Hello everyone, My name is Adam, but you can call me Crash or CrashMechanic, either one it doesn't matter. Well this is my first time on CK site, I found it bbecause I did a search for how to wire a P Cap into a system. I was looking at bying a P Cap and wanted to know what I was getting into before I actually baught it(because I am a DIY guy.) Now I wanted a P Cap because I am having this problem with major power draw ie lights dimming on hard hits, but thanks to your sight I have learned that I don't need a P Cap, I just need to do some wire changes and maybe a batt. change and my problem should be solved, so anyways just thaught I would give credit where credit was due, Thanx Guys. Now for my question. What are your thaughts on my system and do you have any ideas on upgrades. My system specs are: HU- JVC model KD-LH1100, in the front doors are JVC 6 1/2"(size might be wrong, can't exactly remeber right now), in the rear deck are 2 Infinity 6"x9", and in the trunk are 2 JVC 15" 1000watt MAX/ 600RMS, and to pushall speakers are 2 JVC Warren G signature series amps model KS-AX7300, they push 560watts MAX(don't know what RMS). The enclosure for the 2 15" was built by me it has 2 seperatate chambers sealed off from each other, the enclosure is a sealed type enclosure and the inner airspace is approx. 3.8 cu. ft. Any thaughts, suggestions, or ideas are welcome. Please tell me what you think. I am an amateur installer but would like to learn as much as I can. Also I am thinking of making the enclosure a vented enclosure.
Hope to hears some ideas, and again Thanx
Replies (21)
accusedmonk on 11/1/2003 16:51:12
Welcome to the forum Adam. Glad to see more people come here for help/to help.
A nice large battery 850+ CA's will help. As I've learned already, get a larger alt. I fried mine. I'd get your alt rebuilt, if you haven't already considering that's cheaper. Shoot as high as you can while doing this, around 120-140 is a good area. The cap would still help. Rewiring from alt to battery, ground to battery will help too. Replace what's there with 4 guage. I got lucky and mine already has 4 guage there. I haven't been to long into the car audio scene, but I'm just relaying to you some good ideas to use.
Great idea making your box yourself. I didn't which was rather stupid considering I paid $209 for it. It was too big 6.5 cf, to the needed 5 cf, the ports aren't correctly positioned, and it's not internally braced. It works though, but could be much much better.
I'm bound to have left plenty out, but some of what I suggested should help.
CrashMechanic on 11/1/2003 17:40:59
thanx for the suggestions. now since I am thinking of porting my box myself, I need some knowhow. so far I have what I think is the correct size ports but i wanna make sure before I start cutting away and mess something up, so how can I fure that out. I got the Idea for the numbers I have from the DDaudio site(the the company whore makes the compettiton speakers that the BassMekanik uses), but there numbers were for a 4 cu. ft. space. And also I would like to rebuild my alternator, but as far as I know I can't because my car is a Japanese only car(yes, I am in Japan right now) so I can't find any rebuild kits since everything is written in Japanese, and I can't read Japanese. I am thinking of buying an OPTIMA Battery though.
Swez on 11/1/2003 20:54:36
Welcome Adam of Japan! (What part of Japan?)
When you mentioned all the JVC products in your system, I was thinking... never heard of some of these products before. Am sure they are good stuff... just not familiar with their amps and subs. Sounds good to you? That's all that matters.
About porting... I looked at the USA site and did not find the 15" version... just 10 & 12" DVC's and these were recommended for compact sealed enclosures. (CS-WG1200 was 1.0cf/sub) Same idea as what you noted... 600 RMS, DVC. So ~1.5 cf sealed for a 15" should be about right. Porting may not be recommended for this compact box series sub. They do not recommend ported for the 10"/12" models.
The amps noted.. are those 4 channel amp? Looks like it on the JVC web site:
KS-AX7300
Manufacturer's suggested retail price: $329.95
WARREN G SIGNATURE SERIES
Bridgeable 4-Channel Power Amplifier
Continuous Power (RMS) of 50W per channel into 4 ohms 20Hz-20kHz at no more than 0.08 THD
Max. Power 280W x 2
Pure Class-A Circuit
2 Ohm Stable Operation (2-8 Ohm Allowable)
These amps are rated at 50 RMS per channel x 4 or ~125 RMS x 2 @ 4 ohms bridged/ch. I also note this is a Class A amp... this means a very clean signal, but VERY INEFFICIENT design. These amps must pull a lot of current and delivery only modest power. Good for the interior speakers, but not designed for subs.
If you want more bump and less current drain on your electricals. consider using one 4 channel amp for internal speakers and get a Class D MONO sub amp. Much more efficient design and more watts per dollar too. I see no amps on the JVC USA site that meet your needs very well. The amps noted... are those 4 channel amp? Looks like it on the JVC web site.
A Class D MONO amp would be a big step in the right direction for more sub power. Your subs are seeing less than 300 RMS/each now and with these amps, huge current draw to get that much wattage from a Class A amp. (am guessing 50-60 Amperes/amp)
You have some power management issues already right? What is the fuse rating on that 7300 series amp? (just add up the fuses)
May I suggest that you keep one amp to power the interior speakers and get a more potent Class D amp for the subs. To manage the power draw, a larger CCA rated battery (+850 CCA rating) is definitely appropriate. The ALT in this car... do you know the current output of the stock ALT.? As noted earlier in the threads, you will probably need to dig up a larger output ALT too. Figure 120A min., is about right and some wire gage upgrades too... should get you in the game for a 1000 RMS sub amp.
You may need some help from your Japanese buddies to find an ALT that can do that much power. A good option... look for a truck ALT that can be fitted to your present system. They have more output, a bit larger... but this is one option to look at.
Domo arigato gosiemashta, (I hope I got that right... my Japanese is a bit rusty)
Comments?
Swez
CrashMechanic on 11/1/2003 21:38:22
Thanx Swez, I am in a town called Fussa, it's about 25 miles from Tokyo. I'm stationed here for 1 more yr, I've been here for 2 yrs already. Anyways, I called my wife and got the model number for my subs( good thing I kept the box), it is CS-D3800. As far as the amps go yes it is a four ch amp its the exact same amp as the one you found but I did not know they were that expensive, I didn't pay that much for them, I bought them brand new from the store for only $160, man did I get a deal or what. Now the system really bumps now, but your telling me that if I put a class D amp to the subs that they'll hit harder. Question should I get 2 class D amps 1 for ea. sub or just 1 for the both, and also do you have a recomendation on a brand. To answer your question the fuse rating on the amp is 40a (2 20a/32v fuses). Hie, Douzo, you got your japanese right.
Thanx for your help
Swez on 11/2/2003 10:40:18
Good... we are communicating adequately in 2 languages Hie domo..
Those subs can take a lot more power then you can give them with the amps mentioned. I cannot find any data on that sub model number so it may be out of USA only or an older model?
If you are sure on the RMS power each sub can handle (~600 RMS/ea.) JBL makes a beast of an amp that will do well for these subs. Only need 1 amp here as both subs will be wired to the amp.. one sub to each ouput terminal set is easy.
Have a look at this: http://ikesound.com/product-product_id/209
JBL BP1200.1 $259.00 + S/H (USD)
Output 4 Ohms: 600W x 1; Output 2 Ohms: 1200W x 1 (RMS)
Signal-to-Noise (dBA): >100
Frequency Response (±3dB): 20Hz - 500Hz
Total Harmonic Distortion: 0.1%
Input Sensitivity: 250mV - 4V
Die-cast chassis uses the entire footprint for amplifier cooling;
"Direct-Connect" allows choice of 4 - 8-gauge power and ground cable; High-frequency switching power supply is more efficient, drawing far less current from the vehicle's electrical system.
Four high-level and low-level inputs facilitate constant bass, regardless of head unit fader position; Variable electronic crossover and bass-boost optimize subwoofer performance.
Now, this amp is rated for a max current draw of 114 amperes. But it is Class D, so nominal current draw will be well below 60A. at normal listening levels and a bit more when you crank it up. Couple that with one of your JVC 4 channel amps for interior speakers, looking at 80-120A of current draw. (when you really push the system hard)
Maybe you can head down to the motor pool and see if you can get them to fabricate and install a secondary 120A alt for this car. Use the stock ALT/BAT for the car needs and the 2nd ALT/BAT (Optima Yellow Top 850 CCA) for your audio system.
If you have any friends in the motor pool, this should be an easy thing for them to do for you. Just hope there is enough HP to run that 2nd ALT as it will definitely pull a few HP from a small engine. A regular Kamakizi on wheels is what you can get from this system... sonic boom speaking, I mean. hehe
How does that sound to you so far?
Swez
PS Do you like the Japanese food? I love Sushi of most kinds and other foods I have tried too. Like Supporo, Kirin beers go well... but Sake... kinda bland
Worked for TDK USA in the mid 80's as a Sales Engineer and really enjoyed the difference in cultures... the language barrier was big... but managed to stick it out for ~ 2 yrs. Even learned how to write some faxes in Japanese... but all that is long erased from my mental hard drive. Very interesting experiences while there.
CrashMechanic on 11/3/2003 10:29:44
Thanx alot for the suggestion on that amp, I think that amp will be a gold mine. As far as the Batt goes I found a strong Optima for an excellent price. Here check it out: http://www.batterymart.com/battery.mv?p=OPT-D31A
12 Volts
75 Amp Hours
CCA@0°F: 900 Amps
MCA@32°F: 1125 Amps
J240 Life Cycle: 10,000 to 12,000 cycles
Cycle Life - Deep Cycle: 350 Cycles
Reserve capacity: 155 Minutes
SAE Automotive Terminals
Length: 12 13/16 in.
Width: 6 1/2 in.
Height: 9 3/8 in.
Deep Cycle
Optima part number: 8051-160
This is an excellent deal, this Batt should cover for any system, a bit big though, probably need to fabricate to this akward thing, but at least it will definately get the job done. Now, for the HP issue, don't think there will be a problem. I don't know if you are into japanese cars or not, but my car the Nissan Laurel is kinda a cross between a Skyline and a Sylvia. It has the frame of the Skyline and the drivetrain of the Sylvia and the engine from both. The engine is an RB20DE, the car is not bad for a full size family car. Basically after I get this amp and batt, I can't wait to here what it gonna do, cause its incredibly loud now, I cant imagine how loud it will be when I add these upgrades.
I love japanese food except sushi and I haven't worked my taste buds up to that yet. And I agree Sake is pretty bland, it'll get ya messed up though, but I tend to stick mainly to Shochu. Yeah I enjoy the culture alot, there is a bit aof a language barrier but I usally can get past that somehow, someway. Well, that's it for now, I'm glad I found this site, and I'll be checkin in pretty often.
Talk to every body later,
Adam
PS I allways open to suggestions. As One of my favorite qoutes goes " Taking a chance to teach someone is better than taking no chance at all"- me
Swez on 11/3/2003 12:41:35
No like sushi huh? You're missing out as Tuna, Shrimp and Teka Maki are wonderful. My fav... California rolls ! Udon soups are are good and I like the noodles they use in Udon. Been a while since I had them though.
That JBL amp is killer for raw power and brute reliability. Is 1 or 2 ohm stable and ~90% efficient, so you get a lot of power output ratio from power input. The Class A amps are ~35-40% efficient. Very clean audio, but suck a lot of current for nominal power they deliver.
Not too familiar with Japanese Domestic cars. Know some of the Imports we have here in the States... but sounds like your car is more like a mid/full size sedan and not a compact etc. That'll work!
That battery will do just fine... plenty of reserve current for a large amp. Do you know what the ALT in this car can put out current wise? Hopefully, close to 100A or more, should be fine. I happen to like Deep Cycle batteries as they can take many charge/discharge cycles. A regular car battery may have 8-10 recharge cycles before you can throw it away. They don't deal well with deep discharge issues.
Finally, you think the system rocks now... wait till you get a 1200.1. That will really blow you away and use 1 of your 4 channels to kick up the interior speakers. This should help a lot in over all performance if you have decent speakers.
Swez
PS Insanity defined: "If we always do what we have always done and expect different results ... that's true insanity" (author unknown)
CrashMechanic on 11/3/2003 13:23:52
No I don't like sushi, I haven't worked the guts to try it, still got this image that it's pretty nasty. Yeah it's a pretty large car with lots of trunk space, as a matter of fact I was thinking of adding 2 more 15" to give even more thump but I will deffinately have to wait till I get the upgrades done. I was thinking about why my subs hit hard now with only about 120-150wats to each, do you think that maybe it has something to do with the airspace in the box, cause you stated before that it was recomended about 1cu. ft. each chamber, and right now I have 3.6cu. ft. for each chamber. And I will have to find out about the output of the alt. Hey did u ever check out that site I mentioned in the first post http://www.ddaudio.com/ its a pretty good site they got some useful info, not to mention they are they are the company who the BassMekanik uses, they are kinda pricy but they look like they are woth it. anyways talk later
Adam
Swez on 11/3/2003 17:54:01
Yes, I was looking at the DD products the other day and they are well made and can do a nice job on bass as well. Very expensive on the top end of the line however.
About the box you have now... that's a huge enclosure for 15's. It will net loads of deep bass at low power, but the bass definition and punch are probably not as crisp in such a large enclosure. I caould not find specs on the 15" JVC subs, (only 10 & 12".) I would think the 15" is optimal for power and punch (SQL) in a 1.5 - 2.0 cf enclosure when sealed. You may have to go back into your product install spec sheet fro details.
NOTE:
Smaller sealed enclosures permit more watts into the sub to reach full SPL. Not much deep bass, but plenty of punch. Larger sealed boxes net more low bass, but we lose power input capacity as it takes less power to drive the voice coils to maximum excursion limits. No matter the power input... once X-max is reached, the SPL will not increase and can damage the sub mechanicals long before the voice coils burn out.
This is why it is important to know the sub enclosure specs from the Mfg. In the wrong box... can easily blow a 1000 watt sub with 300-400 watts input power. X-max determines how much power the sub can handle mechanically and the size of the box determines how much back pressure there will be, to balance the sub and avoid overexcursion of the cone & mechanical motor system of a given sub.
Want to see a few great 15" subs for large SPL and Comp applications?
www.adireaudio.com Some very good reading here in the White Papers. The power handling specs are how much the voice coils can take electrically. But depending on the enclosure size and design, need much less power to reach full SPL and X-Max. Pretty efficient subs too.
Tempest: (Not so pretty, but takes SQL to a new level in a sub in this price range)
http://www.adireaudio.com/mobile_audio/drivers/tempest.htm
$150.00 USD/sub
Brahma: (Beauty & a Beast)
http://www.adireaudio.com/mobile_audio/drivers/
brahma_series.htm $439.00 USD/sub
Many of my web friends are using the Brahma/JBL 1200.1 combo now and love em! A real SQL machine!!!
Swez
CrashMechanic on 11/4/2003 12:12:30
I'll have to find the paperwork somewhere at home. I never thaught that going bigger in a sealed enclosure could hurt I thaught it would be good. On this JVC Sub info, I don't think you'll be able to find any info on them. I've been looking for 5 days and haven't found anything yet. I don't understand why there is no info out there, tey aren't an old sub, I just bought them brand new from the store about 2 months ago, but I guess I'll post the info when I find it at home. Once I get all of these upgades done how can I found out how well my system is doing, like testing or something like that.
Swez on 11/4/2003 13:52:51
Have had trouble getting technical details off many Japanese based audio sites. JVC, Kenwood and Sony are all pretty scant on "the details" !
Infinity and Pioneer are generally good to excellent on garnering such information. Go figure...
In Home Theater and Pro sound applications, a 15" sub is designed for larger air spaces. They have very different components and design parameteres that allow them to perform best in large sealed or ported enclosures.
For car audio, compactness in sub enclosure design is needed. So, they have different mechanical properties that allow them to perform well in smaller enclosures. In a way, it is good that you have a modest set of power amps powering that sub now. If you had much more power, it may not last very long in that size enclosure.
My guess, you have very deep, full bass right now. Not much punch in the gut bass, but rather, smooth long tones of full, robust deep lows. Does that thought ring true of your bass system now? That's a large sealed box characteristic.
You may have some luck contacting JVC Technical on the sub enclosure specs recommended by JVC. My guess.. they will say 1.5 -2.0 cf sealed for good overall bass and power handling. Not sure if this sub is designed for ported applications.
As for testing your setup... your ears are pretty good intruments for most SQ testing. Want to hear smooth, clear bass. Not boomy or muddy and poorly defined bass notes. There are several performance test CD's out there that will help pinpoint strong and weak points in the bass engine system.
Also, an SPL meter can help you figure out where the bass peaks and valleys are in this install. A test tone CD and SPL meter will tell you where these variations are based on how much SPL the meter registers at different bass notes. These test CD's are calibrated for bass tones that come into the amp at the same power level, but your subs will react differently to these tones, based on the subs' design, enclosure and car characteristics.
The other method is a good A/C volt meter. You can measure the output voltage at each sub and observe the cone for distortions, once the amp gets close to "Clipping". Since you are using one channel to power each voice coil in the sub, they need to be very closely matched. (balanced) If coil A is getting 18 volts on a given tone and coil B is getting 12 volts at same tone and time, you have a mismatch and tough on the sub as each coil is out of balance. The coil voltages need to equal on the same sub. The amp gains will help adjust for that.
Do you understand this detail? I hope I am not shooting information that is over your head. If yes, say so and will try to simplify as best I can.
Swez
PS About sushi again... avoid Eel, Salmon eggs (Roe), Mackerel, Abalone but pure cuts of Tuna (Maguro) Salmon filet, Yellow Tail Tuna, Shrimp (Ebe), Tamago (egg), Teka Maki & Kappa Maki are all very mild and if fresh... they are wonderful. These are very good dipped in Soy sauce, top w/ ginger root and some Wasabe. Go easy on the Wasabe as it is hot/spicy. A small chunk mixed in soy sauce is very nice!
Try a few and I bet you will like these noted. Some of the others are a bit strong for us round-eyes. SMILE
Look here: http://www.asahi-jc.com/sushi.htm
CrashMechanic on 11/5/2003 13:26:35
yeah cool, I understand. I was a little confused at first but I figured it out. I'm a pretty fast learner, if I just take the time. Now, you say that the out volt should be the same in each coil, but since that doesn't apply to my subs( they are only SVC, I think I might have failed to mention that before......oops), I was wondering If the out volt for each sub needed to be the same. I'm gonna try to look for an SPL meter but I not too sure what I'm looking for as far as brands or if it even matters that much. I already have test CD's(Bassmekanik), so I just need a SPL meter. Also what about a oscilloscope, do you think I might want to invest in one of those.
On the sushi matter, I love all the marine life that you stated............................, but only if it is cooked, for now at least. One day though, I might try it. If I can muster up enough nuts, and and quit being a panty waist about it. It looked oishi( I think I spelled that right) on the site you listed though.
Adam USFLAG
compvr15s on 11/5/2003 13:57:49
if running two subs the output being the same is not that big of an issue, you will just get more movment from one, you will be able to adjust this with the gains though, so shouldnt be a big deal, they you wouldnt be able to get them perfect by sight but close enough. i have an oscilloscope but dont know what its used for, my brother got it a few years back, it looks pretty old. i thought it was some medical equipment or something because of the little screen, has a bunch of dials and such, what is it used for?
CrashMechanic on 11/5/2003 14:15:09
haha my dad used to have one that was pretty old, and it did look like something that belonged in a hospital, don't what he did with it though, but since he is a HAM Radio Operater and an old Radio and Electronics collector he probablly put it away somewhere so that it doesn't get messud up. But anyways they are used to visually measure the frequecy of a given sound. For example, if you played a 45hz tone, you would be able to see a visual representation of that tone on the screen. I believe they are used in the competition scene to maximize performance by figureing what the peak hz to spl level is, so that when you go to comp, you know exactly what tone to play. I couldn't tell you how to use it though, never actually used one just seen my dad use it a couple of time, which reminds me to inform you that it is not just for sound, it is used for radio technical stuff and for electrical measurments too.
Adam USFLAG
compvr15s on 11/5/2003 15:02:09
kewl, thanx alot for the info, maybe ill have to plug it in and mess around with it a lil see if i can figure it out. has lots of knobs and dials lol maybe im just better off leaving it alone lol.
Swez on 11/6/2003 05:48:24
An O-Scope is a handy tool for detecting amplifier distortion levels. You can measure the output signal of the HU at a given tone and not the shape of the waveform and scale the voltage input to get a quality reading.
If you have a 2 channel scope, 1 channel can measure the HU output signal shape and voltage, while channel 2 can measure the amplifier output shape and voltage.
If the sine waves are basically the same, but just more amplitude
(voltage gain) in channel 2... you have a clean, undistorted signal coming out of your amp to subs etc. If the signal is really different in shape on channel 2, adjust gain on the amp to bring it back into line with channel 1 signal shape.
The voltage should be much larger in channel 2 (reading off the amplifier outs) but the shape of the wave form should be pretty much identical. A test tone generator/CD is the right music source for testing with an O-Scope. (40,50,60,70,80 & 100 Hz).
Swez
CrashMechanic on 11/8/2003 11:29:37
Hey Swez, I found the spec sheet on my subs. Here's the specs
Max Power Handling--------1000 watts
Nominal Impedence---------4 ohms
SPL(dB,1W/1M)--------------92
Displacement------------------1.8 liters
Mounting Depth---------------6-7/16 in
Re----------------------------------3.6 ohms
BL(T.M)--------------------------14.16
Vas--------------------------------140 liters
Vas--------------------------------4.94 CuFt
Me---------------------------------189.8 gms
Fs----------------------------------29.6 Hz
Qms-------------------------------4.02
Qes--------------------------------0.634
Qts---------------------------------0.547
Pe[Max]--------------------------350 watts
Xmax------------------------------4.8 mm
Freq. Response---------------15-1200 Hz
Magnet Wieght----------------62 Oz
Voice Coil Dia.-----------------2 in.
Hvc---------------------------------17.5 mm
Hag---------------------------------8 mm
Single Aluminum Voice Coil
Thats about as much as I can give you. I do have a question about it, because most of that stuff looks like mumbo jumbo to. Does Vas stand for the recomended box airspace.
Adam USFLAG
Swez on 11/8/2003 18:11:07
Vas:
"Vas is the volume of air that has the same compliance as the speaker's suspension. Stiff speakers have lower Vas and tend to use small enclosures. Speakers with loose suspension have a higher Vas and use larger enclosures. "
Quoted from: http://www.eatel.net/~amptech/elecdisc/spboxad3.htm
In layman's terms, Vas helps us to determine the enclosure size and type (sealed or ported) that is best for a given sub.
In your case, this speaker is pretty efficient, has a strong magnetic flux density, somewhat loose cone compliance and VERY short X-max. It won't take a ton of power to reach X-max (max. SPL) in a large sealed box. It is not recommended that you use this sub in a ported enclosure... Sealed only!
The reason this sub sounds so good at low power is the efficiency rating, large box and Bl. (magnetic flux strength) The large enclosure helps in this case as the sub cone has very low resistance to overcome cone mass and other motor mechanical structures (voice coil length, spider & surround compliance) If you went to a smaller sealed enclosure, low end bass may drop off a few dB, but the subs could take more power without reaching X-max too soon.
As it is now, these subs will perform very well in a large sealed enclosure and get pretty loud with minimal power input. However, if you load them up with >250-300 watts RMS per sub, they may begin to stress and over excursion is likely. Very bad for subs.
Hope that helps, :-)
Swez FLAG
CrashMechanic on 11/8/2003 19:11:03
Thanx alot that really helps. Well, since I got these for pretty cheap I think I'll play around until I mess'em up then by new ones, I only paid $70 ea for them so it won't hurt to play around and find their limits hehe(what that really means is play'em loud as hell, and piss people of untill they blow)
But Thanx again for your help, and just because this has answered alot of my questions, it doesn't mean I'm gone. Because all my questions aren't answered, ya can't answer'em if I haven't come up with one yet, and there will always be questions. So I am gonna stick around till I'm old and grey or the site goes down(which I hope never happens), because I would like to be helped and to help others if I can. But I am out for now as I can here the old lady callin(stupid cell phones hehe).
Thanx
Adam USFLAGUSFLAGUSFLAGUSFLAGUSFLAGUSFLAG
Swez on 11/9/2003 23:45:47
Yep, do hang around and if you wish, you can take my chair in this forum as you learn. It's a big responsibility... but with time, you will learn a lot for the Golds and others here. We have a very talented group here.
Am older and greying now... so we need to look for a few young bucks to pick up the slack... hehe Don't think I can do this forever... but will try to keep up. The mind is a funny thing. The more you put into it, the more it craves.
Your questions are always welcome and there is no such thing as a dumb question. Not sure we can answer them all... but will do our best.
Swez
bairsjw on 11/11/2003 07:17:20
hows it going, just a comment on the optima batteries... i live on a farm and dad got into hios optima stage about 3 or 4 years ago and we now have about 30 of the bloody things- great when working, like we start our truck on 2 of these where we used to use 4 truck batteries, but expensive and and we have prbably 8 or 10 which are stuffed, obviously duds since some of them are more recent ones we have bought. thay are not sold here in oz around us any more, so ahrd to return any for warranty- justr letting evereyone know they aren't all good batteries, just be careful and don't flatten them completely or anything else that batteries don't like, coz its an expensive battery to be stuffing up. mind you i have one in my car with a stock alt, and i will run the stezza at a good volume at beach parties for several hours and still start the car- pretty impressive!
Hope to hears some ideas, and again Thanx
Replies (21)
accusedmonk on 11/1/2003 16:51:12
Welcome to the forum Adam. Glad to see more people come here for help/to help.
A nice large battery 850+ CA's will help. As I've learned already, get a larger alt. I fried mine. I'd get your alt rebuilt, if you haven't already considering that's cheaper. Shoot as high as you can while doing this, around 120-140 is a good area. The cap would still help. Rewiring from alt to battery, ground to battery will help too. Replace what's there with 4 guage. I got lucky and mine already has 4 guage there. I haven't been to long into the car audio scene, but I'm just relaying to you some good ideas to use.
Great idea making your box yourself. I didn't which was rather stupid considering I paid $209 for it. It was too big 6.5 cf, to the needed 5 cf, the ports aren't correctly positioned, and it's not internally braced. It works though, but could be much much better.
I'm bound to have left plenty out, but some of what I suggested should help.
CrashMechanic on 11/1/2003 17:40:59
thanx for the suggestions. now since I am thinking of porting my box myself, I need some knowhow. so far I have what I think is the correct size ports but i wanna make sure before I start cutting away and mess something up, so how can I fure that out. I got the Idea for the numbers I have from the DDaudio site(the the company whore makes the compettiton speakers that the BassMekanik uses), but there numbers were for a 4 cu. ft. space. And also I would like to rebuild my alternator, but as far as I know I can't because my car is a Japanese only car(yes, I am in Japan right now) so I can't find any rebuild kits since everything is written in Japanese, and I can't read Japanese. I am thinking of buying an OPTIMA Battery though.
Swez on 11/1/2003 20:54:36
Welcome Adam of Japan! (What part of Japan?)
When you mentioned all the JVC products in your system, I was thinking... never heard of some of these products before. Am sure they are good stuff... just not familiar with their amps and subs. Sounds good to you? That's all that matters.
About porting... I looked at the USA site and did not find the 15" version... just 10 & 12" DVC's and these were recommended for compact sealed enclosures. (CS-WG1200 was 1.0cf/sub) Same idea as what you noted... 600 RMS, DVC. So ~1.5 cf sealed for a 15" should be about right. Porting may not be recommended for this compact box series sub. They do not recommend ported for the 10"/12" models.
The amps noted.. are those 4 channel amp? Looks like it on the JVC web site:
KS-AX7300
Manufacturer's suggested retail price: $329.95
WARREN G SIGNATURE SERIES
Bridgeable 4-Channel Power Amplifier
Continuous Power (RMS) of 50W per channel into 4 ohms 20Hz-20kHz at no more than 0.08 THD
Max. Power 280W x 2
Pure Class-A Circuit
2 Ohm Stable Operation (2-8 Ohm Allowable)
These amps are rated at 50 RMS per channel x 4 or ~125 RMS x 2 @ 4 ohms bridged/ch. I also note this is a Class A amp... this means a very clean signal, but VERY INEFFICIENT design. These amps must pull a lot of current and delivery only modest power. Good for the interior speakers, but not designed for subs.
If you want more bump and less current drain on your electricals. consider using one 4 channel amp for internal speakers and get a Class D MONO sub amp. Much more efficient design and more watts per dollar too. I see no amps on the JVC USA site that meet your needs very well. The amps noted... are those 4 channel amp? Looks like it on the JVC web site.
A Class D MONO amp would be a big step in the right direction for more sub power. Your subs are seeing less than 300 RMS/each now and with these amps, huge current draw to get that much wattage from a Class A amp. (am guessing 50-60 Amperes/amp)
You have some power management issues already right? What is the fuse rating on that 7300 series amp? (just add up the fuses)
May I suggest that you keep one amp to power the interior speakers and get a more potent Class D amp for the subs. To manage the power draw, a larger CCA rated battery (+850 CCA rating) is definitely appropriate. The ALT in this car... do you know the current output of the stock ALT.? As noted earlier in the threads, you will probably need to dig up a larger output ALT too. Figure 120A min., is about right and some wire gage upgrades too... should get you in the game for a 1000 RMS sub amp.
You may need some help from your Japanese buddies to find an ALT that can do that much power. A good option... look for a truck ALT that can be fitted to your present system. They have more output, a bit larger... but this is one option to look at.
Domo arigato gosiemashta, (I hope I got that right... my Japanese is a bit rusty)
Comments?
Swez
CrashMechanic on 11/1/2003 21:38:22
Thanx Swez, I am in a town called Fussa, it's about 25 miles from Tokyo. I'm stationed here for 1 more yr, I've been here for 2 yrs already. Anyways, I called my wife and got the model number for my subs( good thing I kept the box), it is CS-D3800. As far as the amps go yes it is a four ch amp its the exact same amp as the one you found but I did not know they were that expensive, I didn't pay that much for them, I bought them brand new from the store for only $160, man did I get a deal or what. Now the system really bumps now, but your telling me that if I put a class D amp to the subs that they'll hit harder. Question should I get 2 class D amps 1 for ea. sub or just 1 for the both, and also do you have a recomendation on a brand. To answer your question the fuse rating on the amp is 40a (2 20a/32v fuses). Hie, Douzo, you got your japanese right.
Thanx for your help
Swez on 11/2/2003 10:40:18
Good... we are communicating adequately in 2 languages Hie domo..
Those subs can take a lot more power then you can give them with the amps mentioned. I cannot find any data on that sub model number so it may be out of USA only or an older model?
If you are sure on the RMS power each sub can handle (~600 RMS/ea.) JBL makes a beast of an amp that will do well for these subs. Only need 1 amp here as both subs will be wired to the amp.. one sub to each ouput terminal set is easy.
Have a look at this: http://ikesound.com/product-product_id/209
JBL BP1200.1 $259.00 + S/H (USD)
Output 4 Ohms: 600W x 1; Output 2 Ohms: 1200W x 1 (RMS)
Signal-to-Noise (dBA): >100
Frequency Response (±3dB): 20Hz - 500Hz
Total Harmonic Distortion: 0.1%
Input Sensitivity: 250mV - 4V
Die-cast chassis uses the entire footprint for amplifier cooling;
"Direct-Connect" allows choice of 4 - 8-gauge power and ground cable; High-frequency switching power supply is more efficient, drawing far less current from the vehicle's electrical system.
Four high-level and low-level inputs facilitate constant bass, regardless of head unit fader position; Variable electronic crossover and bass-boost optimize subwoofer performance.
Now, this amp is rated for a max current draw of 114 amperes. But it is Class D, so nominal current draw will be well below 60A. at normal listening levels and a bit more when you crank it up. Couple that with one of your JVC 4 channel amps for interior speakers, looking at 80-120A of current draw. (when you really push the system hard)
Maybe you can head down to the motor pool and see if you can get them to fabricate and install a secondary 120A alt for this car. Use the stock ALT/BAT for the car needs and the 2nd ALT/BAT (Optima Yellow Top 850 CCA) for your audio system.
If you have any friends in the motor pool, this should be an easy thing for them to do for you. Just hope there is enough HP to run that 2nd ALT as it will definitely pull a few HP from a small engine. A regular Kamakizi on wheels is what you can get from this system... sonic boom speaking, I mean. hehe
How does that sound to you so far?
Swez
PS Do you like the Japanese food? I love Sushi of most kinds and other foods I have tried too. Like Supporo, Kirin beers go well... but Sake... kinda bland
Worked for TDK USA in the mid 80's as a Sales Engineer and really enjoyed the difference in cultures... the language barrier was big... but managed to stick it out for ~ 2 yrs. Even learned how to write some faxes in Japanese... but all that is long erased from my mental hard drive. Very interesting experiences while there.
CrashMechanic on 11/3/2003 10:29:44
Thanx alot for the suggestion on that amp, I think that amp will be a gold mine. As far as the Batt goes I found a strong Optima for an excellent price. Here check it out: http://www.batterymart.com/battery.mv?p=OPT-D31A
12 Volts
75 Amp Hours
CCA@0°F: 900 Amps
MCA@32°F: 1125 Amps
J240 Life Cycle: 10,000 to 12,000 cycles
Cycle Life - Deep Cycle: 350 Cycles
Reserve capacity: 155 Minutes
SAE Automotive Terminals
Length: 12 13/16 in.
Width: 6 1/2 in.
Height: 9 3/8 in.
Deep Cycle
Optima part number: 8051-160
This is an excellent deal, this Batt should cover for any system, a bit big though, probably need to fabricate to this akward thing, but at least it will definately get the job done. Now, for the HP issue, don't think there will be a problem. I don't know if you are into japanese cars or not, but my car the Nissan Laurel is kinda a cross between a Skyline and a Sylvia. It has the frame of the Skyline and the drivetrain of the Sylvia and the engine from both. The engine is an RB20DE, the car is not bad for a full size family car. Basically after I get this amp and batt, I can't wait to here what it gonna do, cause its incredibly loud now, I cant imagine how loud it will be when I add these upgrades.
I love japanese food except sushi and I haven't worked my taste buds up to that yet. And I agree Sake is pretty bland, it'll get ya messed up though, but I tend to stick mainly to Shochu. Yeah I enjoy the culture alot, there is a bit aof a language barrier but I usally can get past that somehow, someway. Well, that's it for now, I'm glad I found this site, and I'll be checkin in pretty often.
Talk to every body later,
Adam
PS I allways open to suggestions. As One of my favorite qoutes goes " Taking a chance to teach someone is better than taking no chance at all"- me
Swez on 11/3/2003 12:41:35
No like sushi huh? You're missing out as Tuna, Shrimp and Teka Maki are wonderful. My fav... California rolls ! Udon soups are are good and I like the noodles they use in Udon. Been a while since I had them though.
That JBL amp is killer for raw power and brute reliability. Is 1 or 2 ohm stable and ~90% efficient, so you get a lot of power output ratio from power input. The Class A amps are ~35-40% efficient. Very clean audio, but suck a lot of current for nominal power they deliver.
Not too familiar with Japanese Domestic cars. Know some of the Imports we have here in the States... but sounds like your car is more like a mid/full size sedan and not a compact etc. That'll work!
That battery will do just fine... plenty of reserve current for a large amp. Do you know what the ALT in this car can put out current wise? Hopefully, close to 100A or more, should be fine. I happen to like Deep Cycle batteries as they can take many charge/discharge cycles. A regular car battery may have 8-10 recharge cycles before you can throw it away. They don't deal well with deep discharge issues.
Finally, you think the system rocks now... wait till you get a 1200.1. That will really blow you away and use 1 of your 4 channels to kick up the interior speakers. This should help a lot in over all performance if you have decent speakers.
Swez
PS Insanity defined: "If we always do what we have always done and expect different results ... that's true insanity" (author unknown)
CrashMechanic on 11/3/2003 13:23:52
No I don't like sushi, I haven't worked the guts to try it, still got this image that it's pretty nasty. Yeah it's a pretty large car with lots of trunk space, as a matter of fact I was thinking of adding 2 more 15" to give even more thump but I will deffinately have to wait till I get the upgrades done. I was thinking about why my subs hit hard now with only about 120-150wats to each, do you think that maybe it has something to do with the airspace in the box, cause you stated before that it was recomended about 1cu. ft. each chamber, and right now I have 3.6cu. ft. for each chamber. And I will have to find out about the output of the alt. Hey did u ever check out that site I mentioned in the first post http://www.ddaudio.com/ its a pretty good site they got some useful info, not to mention they are they are the company who the BassMekanik uses, they are kinda pricy but they look like they are woth it. anyways talk later
Adam
Swez on 11/3/2003 17:54:01
Yes, I was looking at the DD products the other day and they are well made and can do a nice job on bass as well. Very expensive on the top end of the line however.
About the box you have now... that's a huge enclosure for 15's. It will net loads of deep bass at low power, but the bass definition and punch are probably not as crisp in such a large enclosure. I caould not find specs on the 15" JVC subs, (only 10 & 12".) I would think the 15" is optimal for power and punch (SQL) in a 1.5 - 2.0 cf enclosure when sealed. You may have to go back into your product install spec sheet fro details.
NOTE:
Smaller sealed enclosures permit more watts into the sub to reach full SPL. Not much deep bass, but plenty of punch. Larger sealed boxes net more low bass, but we lose power input capacity as it takes less power to drive the voice coils to maximum excursion limits. No matter the power input... once X-max is reached, the SPL will not increase and can damage the sub mechanicals long before the voice coils burn out.
This is why it is important to know the sub enclosure specs from the Mfg. In the wrong box... can easily blow a 1000 watt sub with 300-400 watts input power. X-max determines how much power the sub can handle mechanically and the size of the box determines how much back pressure there will be, to balance the sub and avoid overexcursion of the cone & mechanical motor system of a given sub.
Want to see a few great 15" subs for large SPL and Comp applications?
www.adireaudio.com Some very good reading here in the White Papers. The power handling specs are how much the voice coils can take electrically. But depending on the enclosure size and design, need much less power to reach full SPL and X-Max. Pretty efficient subs too.
Tempest: (Not so pretty, but takes SQL to a new level in a sub in this price range)
http://www.adireaudio.com/mobile_audio/drivers/tempest.htm
$150.00 USD/sub
Brahma: (Beauty & a Beast)
http://www.adireaudio.com/mobile_audio/drivers/
brahma_series.htm $439.00 USD/sub
Many of my web friends are using the Brahma/JBL 1200.1 combo now and love em! A real SQL machine!!!
Swez
CrashMechanic on 11/4/2003 12:12:30
I'll have to find the paperwork somewhere at home. I never thaught that going bigger in a sealed enclosure could hurt I thaught it would be good. On this JVC Sub info, I don't think you'll be able to find any info on them. I've been looking for 5 days and haven't found anything yet. I don't understand why there is no info out there, tey aren't an old sub, I just bought them brand new from the store about 2 months ago, but I guess I'll post the info when I find it at home. Once I get all of these upgades done how can I found out how well my system is doing, like testing or something like that.
Swez on 11/4/2003 13:52:51
Have had trouble getting technical details off many Japanese based audio sites. JVC, Kenwood and Sony are all pretty scant on "the details" !
Infinity and Pioneer are generally good to excellent on garnering such information. Go figure...
In Home Theater and Pro sound applications, a 15" sub is designed for larger air spaces. They have very different components and design parameteres that allow them to perform best in large sealed or ported enclosures.
For car audio, compactness in sub enclosure design is needed. So, they have different mechanical properties that allow them to perform well in smaller enclosures. In a way, it is good that you have a modest set of power amps powering that sub now. If you had much more power, it may not last very long in that size enclosure.
My guess, you have very deep, full bass right now. Not much punch in the gut bass, but rather, smooth long tones of full, robust deep lows. Does that thought ring true of your bass system now? That's a large sealed box characteristic.
You may have some luck contacting JVC Technical on the sub enclosure specs recommended by JVC. My guess.. they will say 1.5 -2.0 cf sealed for good overall bass and power handling. Not sure if this sub is designed for ported applications.
As for testing your setup... your ears are pretty good intruments for most SQ testing. Want to hear smooth, clear bass. Not boomy or muddy and poorly defined bass notes. There are several performance test CD's out there that will help pinpoint strong and weak points in the bass engine system.
Also, an SPL meter can help you figure out where the bass peaks and valleys are in this install. A test tone CD and SPL meter will tell you where these variations are based on how much SPL the meter registers at different bass notes. These test CD's are calibrated for bass tones that come into the amp at the same power level, but your subs will react differently to these tones, based on the subs' design, enclosure and car characteristics.
The other method is a good A/C volt meter. You can measure the output voltage at each sub and observe the cone for distortions, once the amp gets close to "Clipping". Since you are using one channel to power each voice coil in the sub, they need to be very closely matched. (balanced) If coil A is getting 18 volts on a given tone and coil B is getting 12 volts at same tone and time, you have a mismatch and tough on the sub as each coil is out of balance. The coil voltages need to equal on the same sub. The amp gains will help adjust for that.
Do you understand this detail? I hope I am not shooting information that is over your head. If yes, say so and will try to simplify as best I can.
Swez
PS About sushi again... avoid Eel, Salmon eggs (Roe), Mackerel, Abalone but pure cuts of Tuna (Maguro) Salmon filet, Yellow Tail Tuna, Shrimp (Ebe), Tamago (egg), Teka Maki & Kappa Maki are all very mild and if fresh... they are wonderful. These are very good dipped in Soy sauce, top w/ ginger root and some Wasabe. Go easy on the Wasabe as it is hot/spicy. A small chunk mixed in soy sauce is very nice!
Try a few and I bet you will like these noted. Some of the others are a bit strong for us round-eyes. SMILE
Look here: http://www.asahi-jc.com/sushi.htm
CrashMechanic on 11/5/2003 13:26:35
yeah cool, I understand. I was a little confused at first but I figured it out. I'm a pretty fast learner, if I just take the time. Now, you say that the out volt should be the same in each coil, but since that doesn't apply to my subs( they are only SVC, I think I might have failed to mention that before......oops), I was wondering If the out volt for each sub needed to be the same. I'm gonna try to look for an SPL meter but I not too sure what I'm looking for as far as brands or if it even matters that much. I already have test CD's(Bassmekanik), so I just need a SPL meter. Also what about a oscilloscope, do you think I might want to invest in one of those.
On the sushi matter, I love all the marine life that you stated............................, but only if it is cooked, for now at least. One day though, I might try it. If I can muster up enough nuts, and and quit being a panty waist about it. It looked oishi( I think I spelled that right) on the site you listed though.
Adam USFLAG
compvr15s on 11/5/2003 13:57:49
if running two subs the output being the same is not that big of an issue, you will just get more movment from one, you will be able to adjust this with the gains though, so shouldnt be a big deal, they you wouldnt be able to get them perfect by sight but close enough. i have an oscilloscope but dont know what its used for, my brother got it a few years back, it looks pretty old. i thought it was some medical equipment or something because of the little screen, has a bunch of dials and such, what is it used for?
CrashMechanic on 11/5/2003 14:15:09
haha my dad used to have one that was pretty old, and it did look like something that belonged in a hospital, don't what he did with it though, but since he is a HAM Radio Operater and an old Radio and Electronics collector he probablly put it away somewhere so that it doesn't get messud up. But anyways they are used to visually measure the frequecy of a given sound. For example, if you played a 45hz tone, you would be able to see a visual representation of that tone on the screen. I believe they are used in the competition scene to maximize performance by figureing what the peak hz to spl level is, so that when you go to comp, you know exactly what tone to play. I couldn't tell you how to use it though, never actually used one just seen my dad use it a couple of time, which reminds me to inform you that it is not just for sound, it is used for radio technical stuff and for electrical measurments too.
Adam USFLAG
compvr15s on 11/5/2003 15:02:09
kewl, thanx alot for the info, maybe ill have to plug it in and mess around with it a lil see if i can figure it out. has lots of knobs and dials lol maybe im just better off leaving it alone lol.
Swez on 11/6/2003 05:48:24
An O-Scope is a handy tool for detecting amplifier distortion levels. You can measure the output signal of the HU at a given tone and not the shape of the waveform and scale the voltage input to get a quality reading.
If you have a 2 channel scope, 1 channel can measure the HU output signal shape and voltage, while channel 2 can measure the amplifier output shape and voltage.
If the sine waves are basically the same, but just more amplitude
(voltage gain) in channel 2... you have a clean, undistorted signal coming out of your amp to subs etc. If the signal is really different in shape on channel 2, adjust gain on the amp to bring it back into line with channel 1 signal shape.
The voltage should be much larger in channel 2 (reading off the amplifier outs) but the shape of the wave form should be pretty much identical. A test tone generator/CD is the right music source for testing with an O-Scope. (40,50,60,70,80 & 100 Hz).
Swez
CrashMechanic on 11/8/2003 11:29:37
Hey Swez, I found the spec sheet on my subs. Here's the specs
Max Power Handling--------1000 watts
Nominal Impedence---------4 ohms
SPL(dB,1W/1M)--------------92
Displacement------------------1.8 liters
Mounting Depth---------------6-7/16 in
Re----------------------------------3.6 ohms
BL(T.M)--------------------------14.16
Vas--------------------------------140 liters
Vas--------------------------------4.94 CuFt
Me---------------------------------189.8 gms
Fs----------------------------------29.6 Hz
Qms-------------------------------4.02
Qes--------------------------------0.634
Qts---------------------------------0.547
Pe[Max]--------------------------350 watts
Xmax------------------------------4.8 mm
Freq. Response---------------15-1200 Hz
Magnet Wieght----------------62 Oz
Voice Coil Dia.-----------------2 in.
Hvc---------------------------------17.5 mm
Hag---------------------------------8 mm
Single Aluminum Voice Coil
Thats about as much as I can give you. I do have a question about it, because most of that stuff looks like mumbo jumbo to. Does Vas stand for the recomended box airspace.
Adam USFLAG
Swez on 11/8/2003 18:11:07
Vas:
"Vas is the volume of air that has the same compliance as the speaker's suspension. Stiff speakers have lower Vas and tend to use small enclosures. Speakers with loose suspension have a higher Vas and use larger enclosures. "
Quoted from: http://www.eatel.net/~amptech/elecdisc/spboxad3.htm
In layman's terms, Vas helps us to determine the enclosure size and type (sealed or ported) that is best for a given sub.
In your case, this speaker is pretty efficient, has a strong magnetic flux density, somewhat loose cone compliance and VERY short X-max. It won't take a ton of power to reach X-max (max. SPL) in a large sealed box. It is not recommended that you use this sub in a ported enclosure... Sealed only!
The reason this sub sounds so good at low power is the efficiency rating, large box and Bl. (magnetic flux strength) The large enclosure helps in this case as the sub cone has very low resistance to overcome cone mass and other motor mechanical structures (voice coil length, spider & surround compliance) If you went to a smaller sealed enclosure, low end bass may drop off a few dB, but the subs could take more power without reaching X-max too soon.
As it is now, these subs will perform very well in a large sealed enclosure and get pretty loud with minimal power input. However, if you load them up with >250-300 watts RMS per sub, they may begin to stress and over excursion is likely. Very bad for subs.
Hope that helps, :-)
Swez FLAG
CrashMechanic on 11/8/2003 19:11:03
Thanx alot that really helps. Well, since I got these for pretty cheap I think I'll play around until I mess'em up then by new ones, I only paid $70 ea for them so it won't hurt to play around and find their limits hehe(what that really means is play'em loud as hell, and piss people of untill they blow)
But Thanx again for your help, and just because this has answered alot of my questions, it doesn't mean I'm gone. Because all my questions aren't answered, ya can't answer'em if I haven't come up with one yet, and there will always be questions. So I am gonna stick around till I'm old and grey or the site goes down(which I hope never happens), because I would like to be helped and to help others if I can. But I am out for now as I can here the old lady callin(stupid cell phones hehe).
Thanx
Adam USFLAGUSFLAGUSFLAGUSFLAGUSFLAGUSFLAG
Swez on 11/9/2003 23:45:47
Yep, do hang around and if you wish, you can take my chair in this forum as you learn. It's a big responsibility... but with time, you will learn a lot for the Golds and others here. We have a very talented group here.
Am older and greying now... so we need to look for a few young bucks to pick up the slack... hehe Don't think I can do this forever... but will try to keep up. The mind is a funny thing. The more you put into it, the more it craves.
Your questions are always welcome and there is no such thing as a dumb question. Not sure we can answer them all... but will do our best.
Swez
bairsjw on 11/11/2003 07:17:20
hows it going, just a comment on the optima batteries... i live on a farm and dad got into hios optima stage about 3 or 4 years ago and we now have about 30 of the bloody things- great when working, like we start our truck on 2 of these where we used to use 4 truck batteries, but expensive and and we have prbably 8 or 10 which are stuffed, obviously duds since some of them are more recent ones we have bought. thay are not sold here in oz around us any more, so ahrd to return any for warranty- justr letting evereyone know they aren't all good batteries, just be careful and don't flatten them completely or anything else that batteries don't like, coz its an expensive battery to be stuffing up. mind you i have one in my car with a stock alt, and i will run the stezza at a good volume at beach parties for several hours and still start the car- pretty impressive!
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