Replies (51)
cplkittle on 02/13/2007 22:17:51
How is everything set up right now?
what kind of head unit are you using?
what size wire is feeding these amplifiers?
what kind of box are they in?
are you familiar with the settings on the amplifier and what they do?
What is it exactly that you think you might not be getting that you should?
cplkittle on 02/13/2007 22:20:11
Some of these have 4 voice coils, how are they wired up?
mikel on 02/13/2007 23:35:30
the immortal series subwoofers are quad voice coils. so with 1 pa a3000db amp per sub your wiring configurations will give you either a .5 ohm load which is lower than the amps stability, a 2 ohm load, or an 8 ohm load. are you using all of you voice coils and how are they wired? the amp says it delivers 1800 watts @ 2 ohms. with both amps running you would be drawing far beyond your alternators capability. as for only minor dimming of the lights you may have a config that would put an 8 ohm load on your amps, which isnt nearly enough power to run your sub, alot of people counter in this situation with cranking their bass boost to much and playing at high volume which in this case may negatively effect your sub. getting the most out of your amps without any doubt you need a much larger alternator. what size is your power wire and circuit breaker for safety concerns? a good battery will outdue a car full of power caps in my opinion. post some more info and modifications.
Hoova63 on 02/14/2007 09:24:10
Good day all.
My Subs are wire so that my amps see a 2 ohm load and I'm running a o guage wire from the batt to a d-block and out of the d- block at 4 gauge to the amps. My headunit is a pioneer DEH-P3500 which is older but I like the different things on it that I can control and plus pioneer only upgrades just graphics every year they are mostly the same hu's unless you buy premier! I could be wrong but I was just thinking it should have been a little louder to have been 1800 watts going to each of these subs. My box at the moment is a little smaller than it should be but I will have that upgraded by saturday. I am getting a vented box built almost double the size of this one because It's choking the subs off big time. Please let me know any more info that I have let off that would be needed to help answer this ?.
cplkittle on 02/14/2007 13:29:07
You have 2 subs that have 4 x 2 ohm voice coils, and 2 two channel amplifiers.
First of all, the amplifiers are stable at 4 ohms bridged, or 2 ohms per channel. My suggestion would be to run both speakers off of one amplifier. One on each channel at 2 ohms each.
The ideal setup would be a single channel amplifier stable at 1 ohm that could deliver 4000watts RMS.
Hoova63 on 02/14/2007 17:25:26
The amps are monoblock if that makes a difference 1800 watts@ 2 ohms, 2300watts@1 ohm. I wish I would have gotten the 4000 watt amp at first but I didn't so know I have an amp on each sub at 1800 watts going to each sub. Would beefing up my alt to 220 amps help any or will I have to do that plus?
cplkittle on 02/14/2007 18:50:57
Of course it would help some, but would you notice a difference? maybe a little. Is it worth the money? it depends on how much you spend on the alternator. Before you spend $400 on an alternator, I would suggest a $200 optima yellow top battery.
I looked up the amplifier, and it said it was a 2 channel. maybe I got the model number wrong.
One more item to address.. Is the box one common chamber, or is it divided in the center? When using seperate amplifiers it is better to use a chambered box. Even though the amplifiers are exactly the same, it is impossible to get the amplifiers set the same, and any difference in output will negatively affect the performance of the other speaker when they share airspace. More so in a sealed box.
Hoova63 on 02/14/2007 21:14:09
The new box being built will be divided and a vented box, which is going to be my next thing cause I wanna be sure the vents are tuned right to my listen taste and what size they are actually supposed to be so I can make sure I don't get screwed over. When I get the yellow top battery should I replace my front battery also because I've noticed in a lot of forums they say that and also wouldn't that put more strain on my alt to charge two batteries and run a system? Jus wonderin
cplkittle on 02/14/2007 22:20:36
replacing the battery up front with a yellow top should be all you need, but it is difficult to say until everything is hooked up and running. I always recommend the battery first. If you decide to get an alternator later, you will need the battery anyway. It's like having a job that pays 6 figures and trying to cram the money in a piggy bank. You need a battery with the capability to store as much energy as you can.
As far as the port size that all depends on the tuning frequency, the size of the box and the characteristics of the sub. Everything is directly related.
The Audiobahn immortal 12" subs have an EBP of 151. These should be in a ported box, no question. According to WINISD, a box for your subs tuned to 35 Hz could have the following dimensions:
1.25 cubic Ft internal volume
Port would be 2"wide x 12" tall x 38" long
1.75 cubic Ft internal volume
Port would be 2" wide x 12" tall x 26" long
Now if we change the port opening size..
1.25 cubic Ft internal volume
Port would be 2" wide x 6" tall x 18" long
1.75 cubic Ft internal volume
Port would be 2" wide x 6" tall x 12" long
You have alot of room in tha back of that grand cherokee, so you could go up to 3 cuft per sub. In my experience, smaller boxes with long ports hit harder. On the other hand, larger boxes produce thicker heavier bass. The differences are not major, but having built hundreds of enclosures, I have noted a difference.
How good are you with wood working? If you want, we can walk you through building your own box. Even if you only have novice experience in carpentry this can be done in one day.
jamesp on 02/14/2007 22:37:00
Cplkittle, I am interested in building a ported box for my Alpine 12" type R sub. The data sheet says I need a 1.7 ft^3 box with 15sq/in slot or port. How did you determine the smaller of the two port sizes in your calculations above. Thanks
cplkittle on 02/14/2007 23:02:11
I use winisd, a pretty cool program from linearteam. It takes a little bit to learn, but basically you plug in the T/S parameters on the sub and it does all the calculations for you as well as recommends the proper box (sealed/ported) and optimum size / tuning frequency.
I can figure the port size for you if you want, just tell me what size you want to work with and what the tuning frequency needs to be and I'll give you some port sizes. You can go with a smaller box if you want.. It all depends on how much room you have to work with.
Hoova63 on 02/14/2007 23:04:00
Once again I wanna thank you cause u r a big help to me right now.I'm gonna try that battery first just to save a couple of bucks. As far as the box is concerned I am not much into carpentry but I can read a tape and things like that. It pretty much jus depends on how hard it would actually be. But I have been trying to learn how to build boxes. As far as the cuft per sub that is actually about what they recommend so I was actually gonna shoot for the 3. I'm don't have any experience with box building but I downloaded Winsid and tried to read it and got lost in the first 2 min. Haha. But I'm always willing to learn.
cplkittle on 02/14/2007 23:12:33
winisd took me about 4 months to figure out, but I was lucky, I was working for a car audio shop at the time and there were people there that could explain theile small parameters to me and kinda help me figure it out. The guy that taught me everything was the ultimate old school mentality, so if it wasn't done on paper it wasn't right. So I was kinda on my own, but I was allowed to experiment alot, and quite a few of my boxes went into the dumpster ( I had to pay for those ). If they sounded good, we sold them.
The instructions are VERY technical, and I don't understand some of it. I know how to use the program, but I couldn't explain everything.
cplkittle on 02/14/2007 23:13:43
The requirements for building a box are 1 having a good saw that can make straight cuts, and 2 a decent amount of patience.
Hoova63 on 02/14/2007 23:15:45
I got a guy who actually can do this stuff I jus wanna make sure it's right cause he kinda did my first box to small.So I jus wanna make sure it's right.I wish I could get ya'll to do one and mail it to me or something.haha
cplkittle on 02/14/2007 23:20:19
Tell me the dimensions you have to work with in your vehicle, and I will give you the measurements you need.
I need to know length, width, and height. that will fit in your jeep, and I can design it for him to build.
It would cost a small fortune to ship a box to you. You have some pretty stout speakers, and the box would need to be 3/4 MDF. and probably a sheet and a half. total weight would be somewhere around 60-70 lbs without the speakers. UPS would charge somewhere around $125 for that.
Hoova63 on 02/14/2007 23:27:36
I will get all the dimensions and relay them to you tomorrow but say I would rather you actually build the box about how much would you charge to do a box like that. Also I notice your name says georgia so picking it up is also an option because I stay right here in SC. But again I will relay those dimensions to you in the morning just in case you actually doing it isn't an option.
cplkittle on 02/14/2007 23:37:28
I don't mind building one for you. It may be 2 or 3 weeks before I can get to it. I live ~50 miles north of Atlanta (almost in Chattanooga), but my current occupation is industrial sales for the state of Georgia. Matter of fact, I am heading out to Augusta tomorrow morning for a meeting with John Deere on Friday.
Bottom line, I will be in and out of that area a bit for the next month or so depending on how this meeting goes.
If you are patient and can wait, I would be happy to. I need to schedule a trip to Savanna as well if that is closer.
We try to keep business seperate here, so if you want you can email me at cplkittle@yahoo.com to discuss pricing and what not.
It would be cool if we could meet up friday if you are going to be in that area so I can see what you have now and figure out what you want.
Hoova63 on 02/15/2007 00:23:46
I'm actually going to head to ohio on friday but let me know when your trip will be to savannah and that would probably be a good day.
swez on 02/15/2007 00:55:08
This is what I really like to see at CK... a guy with skilled hands, helping a guy who wants the best performance he can get for his hard earned buck!
Hoova, you are in skilled hands and I have intentionally stayed out of this one so that you and Kittle can work out a plan of attack. If you are willing, Kit is able. It does not get much better than that. Keep up the dialogue so that others will benefit from the details as well. Just keep your financial dealing private.
Power Acoustik makes some decent mid-level power amps. They can take a beating and the Immortal subs should be up to the task as well. Kit mentioned a strong battery as your 1st step and I agree. Ask him to walk you through the "Big 3" wiring upgrade so you can get the most current flow from the ALT/BAT to your amps and subs.
Frankly, I cannot see a 90A stock ALT keeping up the power need of these 2 strong amps. Depending on your listening habits, may need a H.O. ALT anyway. As a source, contact:
http://www.motorcityreman.com
See what they can bring to the table for your needs. Stinger and Ohio Generator are also great products. But they are very expensive and support a niche market.
Swez
Hoova63 on 02/15/2007 08:19:44
Thanks also swez. Cause one of my next ?'s was actually going to be about the "Big 3" and exactly what that was. I have seen it in many forum and never asked what it was in fear of sounding stupid. But I'm comfortable here and the only stupid ? is the one "unasked". If that's a word.haha. Also kit I passed out last night but I'm gonna get those dimensions to you in a little bit here. Just so I can see what the design would look like
Hoova63 on 02/15/2007 08:25:13
Also I just checked out motorcityreman and they have a great price on the alt but I can only get up to about 160 amps will that suit me for this application.
Hoova63 on 02/15/2007 08:42:44
I think I have figured out the big 3 if that is what that is on the motorcity site.The only thing I'm still wondering is does the pulley that needs to be smaller come with the new alt and can I get the wire with the new alt also?
swez on 02/15/2007 08:48:42
Here's a tuitorial link for the "Big 3" upgrade.
http://forum.sounddomain.com/ubb/ultimatebb.php?ubb=get_topic;f=5;t=007801
As you say, there are not many stupid questions here at CK. We try to teach... not bash.
It looks like each amp will draw about 150 - 160A's per amp at full power. 1/0 wire is designed to carry up to 300A's. That part is good.
However, a lot of this depends on how you use your gear too. As a daily driver, most guys don't go boomin' through town at full bass power. Those who do will eventually be cited for excessive noise and be ticketed as well. (Appropriately so) Here, a single sub and amp are more than sufficient as a daily driver. Just turn off the 2nd amp and sub.
When competing in DB Drags and such, that 160A ALT and dual batteries may be enough, along with the Big 3 upgrade. (Use 1/0 wire here too) Burp tones are a big drain on the electrical system and a 2nd BAT will help with short-term current demands.
You may wish to consider a pair of single ported sub enclosures here. Using 1 amp and sub as your daily driver. When competing, go for broke and use both amps and subs to hit your best numbers.
Comments?
Swez
Hoova63 on 02/15/2007 09:44:04
Thanks swez that was very helpful. I think I will try that with the yellow top upfront first and see what that will do. And leave the alt as a last resort.
Hoova63 on 02/15/2007 11:47:12
Just one more ? not to doubt anything anyone is saying but I spoke with an auto electrician about getting my alt beefed up and he said something like."The alt is never actually gonna see the output that it's rated at putting out from different experiments he has done and that it would be pointless to beef it up. He told me just not to run it long and turn off all accessories possible when playing it loud. He said that bigger alt only have a bigger die or something like that in them that can allow them to take more heat but that about all that is different and maybe a few more amps of juice but never what it's actually rated at. Now this is like 45 years exp. talking to me and I have none so it's hard to fig out that's why I turned to you guys.
swez on 02/15/2007 12:38:08
Your electrical guy is pretty close but may have left out a few details is all. H.O. ALT's are often larger casings, bugger windings, HD brushes and armatures and high current diodes and regulators.
I too had an old timer rebuild one of my ALT's a few years back. He'd been doing this kind of work, (ALT's and Starters) since the 50's and he took me back to his work shop and test area as he did my ALT.
As he pulled the core apart, he showed me the guts and explained each function. (I just played dumb and let him talk) Then he replaced the regulator kit with a H.O. version, installed fresh bearings and brushes and tested the diode pack. He alslo cleaned everything up nice and shiney and then put it back together and tossed it on his test jig for voltage and current tests. I started out w/ a 105A... went home with a 120+ amp version.
The main thing here, ALT rotation speed, determines the output capacity to a given load. At idle speed, we get ~50-60% of rated power from a given ALT. At 2,000 RPM or so, the ALT is spinning fast enough to develop maximum rated power. Some guys will often use a slightly smaller pully drive to increase ALT speed at idle. This is a common trick in racing too. These guys need/want full spark potential off the line. Also, a well balanced ALT can operate above 15,000 RPM.
OK, so much for this... yeah, try what you have for now and see how it goes. If you find a need for more juice to power these big amps, you know the drill.
Swez
cplkittle on 02/15/2007 19:33:19
The smaller pulley trick is pretty big down here. Most of the IASCA events I have been to disqualify you if you rev your engine over 1500 RPM. One of my customers had an alternator rebuilt for a monte carlo with a variable voltage controll mounted in the vehicle. He could crank up the output of the Alt to 18V through a potentiometer. It has something to do with vehcles that controll output via variable resistance. Too bad he was using JL 1000/1 amplifiers and didn't really need it with their regulated power supply.
Good idea though. I think he paid somewhere in the neighborhood of $240 for a 180 amp alternator.
Hoova63 on 02/15/2007 20:25:07
Sorry took so long but I just went out and got those specs for the trunk of the jeep.
42.5 inches wide
21 inches deep
19.5 inches wide
This is the space that I have to work with and the subs call for like 3.4 cu ft of air space and have a displacement of 0.4 which I don't know what that means.haha. Sorry trying to make humor out of being lost here
Hoova63 on 02/15/2007 20:40:25
Also if you need any specs on the subs I have them also cause I might actually try this myself. Depends on how the numbers look when I get them back and how hard it might possible be.
cplkittle on 02/15/2007 23:24:12
ok, internal dimensions using 3/4 MDF would be 41x19.5x18 = 8.328 cu ft. minus the displacement of the divider (.152cuft) = 8.176. Divide that by 2 and you get 4.088 cu ft, minus the sub displacement gives you 3.688 cu ft per sub.
Port size will be as follows:
2x12x:
13" deep = 32Hz
12" deep = 33Hz
11" deep = 34Hz
10.25" deep = 35Hz
9.5" deep = 36Hz
The port displacement is figured in to the calculations. Luckily you got pretty round numbers. If you need port lengths for round ports, let me know and I will convert it for you.
If you want to build it yourself, here are the sizes of each piece:
Top and Bottom 19.5 x 41
front and back 19.5 x 41
end pieces 21 x 19.5
center divider 19.5 x 18
The front and back will be on the outside of the top and bottom
A side view would look like this : l-----l Where the bottom piece and the top piece are sandwiched by the front and back. This way all 4 pieces can be cut the same size. Also, you want the front to be a solid piece for stability from top to bottom. The ports should be cut seperately and glued and stapled/screwed/nailed into place. A flush tip router bit will cut the port holes in the front nicely and keep it flush with the walls of the port. Remember to make the port 3/4" shorter to compensate for the thickness of the front piece of MDF. If you don't it will tune it almost 1Hz lower than desired.
Any questions?
Hoova63 on 02/16/2007 09:01:44
Is that just one single port and where should I place it if so. I think the only thing I'm really lost on now is the port because I think everything else is pretty easy.
cplkittle on 02/17/2007 14:20:47
There needs to be a port for each speaker.
The port needs to be on the same side of the box as the speaker.
If you go with 33Hz, for example, build a rectangular slot with the interior opening of 2"x12", and make it 11 1/4" long. Place it on the inside of the box and attach it to the front of the box. Drill a hole in the front of the box where the port opening is, and using a router with a 1" flush tip bit, you can cut out the face of the box flush with the port. by making the port 11 1/4 instead of 12" long, with the 3/4" thickness of the front added to it, you get the 12" length.
Other than that it can be above, below, beside the speaker, vertical, horizontal, diagonal, and if I recalculate the interior airspace, you could put it on the outside of the box. In other words it dosen't really matter.
jamesp on 02/17/2007 17:43:13
Cplkittle, arere you using WinISD or WinISD Pro? I cant use yhe regular version at all and the PRO version is giving me fits.I am not having much luck entering my Alpine SWR 1242D. I enter the parameters that I have and the auto check fails for the QMS, QES and QTS. I am entering the values from the data sheet and making sure the units are correct. There is not a value for every parameter specified and I have the "auto calc"(may not be the right term) box checked. I wonder why there are no Alpine products in the data base???
Also, from the above post, it sounds like the slots framed on the inside of the box and not just cut into the front box panel. I went to the audio shop eariler but the owner was out and I didnt get any good info to help me. I just want to try a ported box w/ my sub.Thanks.
cplkittle on 02/17/2007 18:19:11
Winisd pro will kick out your parameters if they are not exact. Most manufacturers will either fudge a little or round the numbers off. Make sure the auto calculate unknown box is checked, and enter one number at a time. After you QMS and QES, hit tab until you get to Fs. Qts will auto calculate to a higher decimal place or slightly off than the manufacturer's information. After that enter Vas and hit tab 4 or 5 times until some of the other blanks fill themselves in. It's a little quirky, but very accurate.
I have also found out that it will not save if you enter a number, then try to change the unit of measurement, so make sure the unit of measurement is correct before entering the value.
The easiest way to do a port is to build the hollow rectangle port, then place it into the box with one opening against the front of the box, then that flush tip router bit does a perfect job of cutting the port-sized hole in the front of the box. If you try to cut the hole first and put the port up to it, you will be sanding trying to get everyting flush. If you cut the hole large enough to slide the port into the box, it makes a nasty mess where you have to seal it up. Using the method I suggested is the quickest, cleanest, most professional looking method.
Another method is to build the port with only 3 sides, and use the bottom of the box as one of the sides. It is not as fast because you have to build it into the box halfway through the construction of the box. Another setback is that it is harder to keep the inside of the port clean (glue). If you get glue on the inside of the port it looks bad. I usually spraypaint the inside of the ports black, and the glue dries slick and dosen't absorb the paint like the wood does (it usually takes 3 or 4 coats). The glue will give you a slick shiny painted finish, and the wood will be a flat finish.
jamesp on 02/17/2007 18:38:55
Thanks for the info. I was entering my value then changing the unit of measurement..then changing the value if necessary..The data sheet on this sub has a recommended external dimension listed for a vented box as well as vent size. The recommended size is 18"x13.5"x16.5" Then it gives a vent area at 15in sq.(12x1.25) and a vent length of 22.75in. It does not say what frequency this is tuned for....Dont mean to hi-jack this thread but that sound like a decent first time box to build. Then when I have my tools set up I can try to get creative...what do you think??
Hoova63 on 02/17/2007 19:54:56
Well Kittle I wanna thank you man, my box came out great perfect fit and everything. And man let me tell you it's loud or loud enough for me that is.But that power problem is gonna have to be fixed for sure. It's draining like crazy now and I didn't even put the other amp in yet. But I'm gonna try another batt first and see if that works.Everything in the car is blinking now.haha. Never ending battle in car audio.
cplkittle on 02/17/2007 20:00:28
That comes out to somewhere between 27 and 29Hz depending on the thickness of the wood.
I don't know that I would tune it that low. If you shorten the port to 14 1/4" That will give you 34Hz.
Building a box with a port that has to wrap around more than one wall of the interior is not exactly easy. Would I suggest it? Of course! Once you build a box that detailed, everything else is cake.
cplkittle on 02/17/2007 20:09:04
Hoova,
just missed your post there.
I'm glad it turned out well. That was pretty fast! Did you build it yourself?
I think a battery will make a big difference, but remember the battery only stores energy, and the amplifiers are pulling more than the alternator puts out, so common sense tells us that you gotta give the stereo a little down time and let the battery charge up a little. Plus, you don't want to do too much damage to your ears. I was one of those wide open guys for a couple of years, and now I have to hold my cell phone up to my left ear if I want to understand anything. It sounds a little louder in my right ear, but it is distorted.
I am only 30, and believe me, I would definitely do things different if I had a chance.
mikel on 02/17/2007 20:50:03
James, with the program i use the parameters for the alpine swr-1242d gave me and fs=29, qms=7.89, vas=1.589cf. for electrical in parallel qes=.5, re=1.85, qts=.47. for seperate config the electrical parameters are just doubled. your ebp is 58. let me know if this is any help to you as id like to know. i didnt fiddle around with boxes and response, but i can do so tomorrow when i have time. for my driver settings i only allow a 3% tolerance, which is helpful because as you said manufacturers specs are very often incorrect, and if specs dont coincide i would often not know. good luck, get back to me.
jamesp on 02/17/2007 20:54:09
Cplkittle, is 34Hz a good tuning point. The shorter port will be easier to deal with too. If a long port was needed could I run it along the top and turn it down the side of the front panel if the front panel is overlapped by the top panel and the end panel?
Hoova, man you are into speed building, huh? You need to let the glue dry before you crank it up too much. What did you caulk the box with. Have you covered it yet? Post a link to a picture if you get a chanceGlad to hear it sounds good.
cplkittle on 02/17/2007 21:32:45
You can run it all the way around the box twice if you have to. Just remember that port length in a turn is measured to the center of the airspace. Man this is hard to explain without doing it in a kindergarden tone.. No offense.
Let's say the port is 12" tall, 2" wide, and 24" long.
The interior of the box is 16x16. The port can run the length of the bottom, but dosen't mean that you get 16" of port length, the port is 2" wide, so you subtract half of the port width. Now you have 15" of length. When you make the turn you have to take into account half of the width again, but this time you add 1" because you are measuring from the center of the airspace in the port, which is 1" lower than the top of the port at the turn before the rest of the port is added. 24-15=9, but you gain an inch, so you only need 8 more inches after the turn.
I know that was long winded, but this is something that is easier drawn out than explained. There are alot of factors that can change the tuning of the box, but once we have it narrowed down this far, the length of the port will not affect the tuning to an extreme extent. you are pretty much to the point that 1" too short will only change it by 1 Hz. (shorter will tune it higher, longer will tune it lower) basically your margin of error can be almost 20% and you will still be somewhere between 32 and 36.
jamesp on 02/17/2007 22:23:35
Thanks for taking the time to answer the Q. Believe me, when I ask a question , Im not going to take offense at someone trying to explain it where I can undertand it..
I bought a book called Car stereo Cookbook that has some sub box stuff in it, Ill check it out.
Hoova63 on 02/17/2007 22:27:02
No actually a friend of mine did it but I learned alot from it. I watched him since like 7 am this morning and got done maybe around 6pm but we also ran my wires again though so that took a lot of extra time also.But I could probably build my next box though with some number assistance but I got the physical part pretty down packed.It's almost like legos.lol
jamesp on 02/17/2007 23:51:41
Mikel. sorry, somehow I didnt see your post. Ive been looking at this book I bought. I think it may help make sense out of the TS numbers for me. What program do you have?Ill see what I can come up with tomorrow. Thanks.
mikel on 02/18/2007 01:57:58
the program i use is bassbox pro by harris technoligies inc. in my opinion its a great program. it has tons of drivers listed as well as an uptated database. enclosures, crossovers and all shows different types of data for drivers, types of enclosures and all of there responses. the graphs are usefull as it shows normalized and amplitude response and max acoustic power, electrical input, cone displacement, vent air velocity, impendence resopnse, phase response, group delay etc. for parameters it takes in eveything and shows all different configurationsand then moves into all types of enclosures so you can design and modify alot to see what will work well for you. several very helpful aspects are within all of the graphs and comparing differences among things like port sizes, shapes end types dispacement, multiple vents, fill and its effect. with parameters not in the database it will show if one or several are not in place with rest, which helps with the manufacturers specs which seem to often be off, or speaker capabilities exaggerated. aside from the program books like the loudspeaker design cookbook by lance dickason are incredible. i still have a ton to learn about the program and this book. this book is invaluble as the author is phenomenal and covers more information on speakers, enclosures, design possibilities, while showing graphs by leap to show you the differences in all he is talking about. for the book i would defiately suggest. the book your reading now is pretty good as it shows alot of different aspects of audio/video in general. software, as expensive as some programs are i would make sure i wanted the program befor investing as you could use the money somewhere else. good luck
jamesp on 02/18/2007 12:35:54
Mikel, I reinstalled Winisd on my laptop this AM and I cant get it to cooperate with me.
I doubt if I will ever invest in box design software. I have only recently become interested in car audio again. I was interested in it when I was younger in the 70's but there was really no decent 12V stuff around then.LOL We thought our stuff sounded good, if you jammed the pack of matches against the left side of the 8 track tape just right it kept it from dragging. If I just knew what dimensions would work best, I would be ahead of the game...maybe.
My daughters boyfriend had a system installed at a Best Buy or Circuit City a few months ago and I thought it sounded very good at first.Now I know that he has a very poor system . The stuff I have put in my truck lately sounds a lot better than his SQ wise and probably SPL wise.LOL.
I am having fun upgrading my system and just want to knock out a ported box to see if I like it. I love the tite,accurate sound I am getting from my sealed box but I dont have much to compare it too.
My friends, that are around my age, are looking at me kind of funny when I pull up and the tannau cover on the bed of on truck is pulsating(not really) I am having fun with it. JamesP
mikel on 02/18/2007 19:24:57
james, if your using .75" material i came up with dimensions of 12.6 by 12.6 by 20.78. with a 4" port flush end,at a length of 16.33 and a tuning frequency of 32hz. this box totals 1.75 cf and takes into account all displacement.this sub has a pretty low ebp so id imagine your sealed enclosure as long as its the right size, and suites your taste sounds good. but this looks like it will work well. how much room do you have for your enclosure?
jamesp on 02/18/2007 20:12:39
Mikel, my sealed box started out at 1 cu/ft and I shimmed it out with some luann pieces and attached poly-fill material about 2" thick all around. It does sound good. Thanks for determining the boxs size for a ported box. I have a new head unit (Eclipse CD 5000) coming in next Wednesday so Ill hopefully get my factory HU changed out next weekend then Id like to build a box. I have plenty of room to put a box that size in where my sealed box is behind the driver side seat. The sealed box is 12 x 13 x 16 and I have it firing up. I can do the same thing with the 20.78" box if that will work well. Are those the outside dimensions? Again, thanks.
mikel on 02/18/2007 20:49:50
james i apologize those were internal dimensions i posted, external are 14.1 by 14.1 by 22.28. let me know how this works out. give me feedback on the enclosure and the hu. with a stock hu now it will make a big difference im sure. good luck
cplkittle on 02/18/2007 23:41:41
Hey James and Mike,
Could one of you start a new post discussing box building programs? I would like to mark it as a FAQ, but I don't want to mark this one since it is so long and it started out as a different topic. There is alot of good information going back and forth here, and I would rather it not get lost in the archives.
Thanks
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