hi i Live in NYC. Lots of competiton!! I have a 15" Power Acoustic MOFO and a 15" Alphasonik 800 series. I have the Boss gt2500d and Legacy Predator 2 ch 4000 watt amp(bridged) I have a 5.0 farad capacitor from Power Acouistic. I ran three 4 gauge wires from the front of the battery(Duralast Gold i think about 820 -1000 cranks) which is also new. 4 gauge wire is ran to the back underneath the SUV and nice and neat. I grounded a 4 gauge wire from the front to the chassi and grounded all the amps and capacitor to a big bolt, bolted on the frame of the truck. and i used a distributor block for one of the 4 gauge wire to send power to another amp for four 6x8-9 speakers (which only one is currently "hooked up")and the other 4 guage to the capacitor. I made a fiberglass box in the back near the passenger side quarter panel in the very back. holds the two 15" subs and one 6x9 speaker. Now the fiberglass sub is ported from the back and sealed from the front. I used alot of fiberglass clot and mat and resin ..sprayed undercoat spray (rubberized) to be used as a sound deaden in the inside of the sub. and used carpet insulation well taced in the inside afterwards. Subs mount nicely on double mdf rings for both subs. SUppose to be light but witht the subs and everything the box is very heavy, need two men to pick it up. The problem im having is the speaker or something doesnt play loud enough.. seems like a waste of time. please comment thank you
Replies (29)
chrisrohit123 on 06/5/2007 01:07:11
2001 FOrd Explorer sport. I think its the wire i invest money for the 4gauge wire and i think i need 0-2 guage because of the length of my suv.
newB on 06/5/2007 02:06:55
i think i follow.
now- i would look into several things.
voltage drop may be an issue, depending on the stock electrical i would recomend running your big 3 under the hood with extra 4ga. a bigger power wire always helps and if you do decide to upgrade you can use your old 4ga for the "under the hood" upgrade.
also consider this fiberglass box. the way the woofer(s) behave depends on the enviroment they are placed into. how are they ported? areo port?
what is the tuning frequency?
and net internal volume of the box?
check things like phase as well
let us know and keep us posted
-Drew
chrisrohit123 on 06/5/2007 12:35:57
I don't understand the part you said "running your big 3 under the hood" that part i dont really understand. I have a 3 way crossover with a phase. The port is facing the outside or the opposite of the speaker. Facing the truck wall. I also was thinking maybe i need a better alternator. I just changed the battery terminal which has one 0 gauge one 4 gauge and two 8 gauge. I used the three four gauge in the 0 guage which barely fits. The 4 gauge was used for the car wires. I am going to get a better terminal as soon as i get more funds.What do u suggest for a good terminal to accomodate my wire setup. DO you think upgrading to better alternator and 0-2 gauge wires will help significantly. Also i used the subwoofer output from the head unit which is a JVC KD-G725. has a usb input which is great and it 50w x4. I really want this thing to sound good because i had the alphasonik first originally installed and that speaker sounded nice with just the legacy predator amp and the capacitor. Now with all this stuff its sounded like a waste of my time. FIxing from morning untill night. Now im having second guesses since my results are not expected to be. Please help with your advice.
chrisrohit123 on 06/5/2007 12:56:10
heres some pics i took today.
chrisrohit123 on 06/5/2007 12:58:10
Heres some pics
http://i196.photobucket.com/albums/aa80/chrisrohit123/1st.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/electsetup.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/Box1.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/Crossover.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/SIde.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/batteery.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/Batteryposterminal.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/DSC00072.jpg
30Hertz on 06/5/2007 13:00:43
Pictures here would speak a thousand words. We
We also need more information on your equipment. We need Model Numbers, and more specifications on your subwoofers.
What is the exact model number for your Legacy predator? I've looked at for the specs and from every website I gather, its 4000watts MAX POWER bridged but does not give you an Ohm load that it can handle for bridging. The marketing for this amplifier is shady at best.
What is the voice coil configuration for your subwoofers? Are they Dual Voice Coil (DVC) and what OHMS are they? 2, 4 ?
We generally prefer to not mix subwoofer brands due to the fact that T/S parameters vary from make to make and model to model which can affect performance if both are in a single chambered enclosure.
You say you have a 6x9 also in the panel, is this built into the enclosure so its sharing the same airspace as the subwoofers? Or is it in its own seperate compartment away from the subs?
Why did you run multiple runs of 4guage wire? A single run of 1/0 guage would be fine here. Generally we need to have the same size wire going to the ground as we would for the power, installing multiple runs of 4 guage with only 1 run of 4guage ground doesnt fit the bill but will probably work.
I dont see voltage drop really being the culprit here in your lack of wangage.
My gut feeling is telling me 2 things here. A. Your enclosure isnt built correctly for these subs and B. Your lacking in the power department.
What is the total ^ft of your enclosure? I've run the 12" Power Acoustik MOFOs and they are an airspace hungry woofer. A single 12 needed 3^ft and could only be run ported. The 15 would most likely require more. Are both subs installed sharing a single chamber? or is it a dual chambered box?
What size port do you have installed and what is it tuned to?
This is enough for now. Plz respond with the information requested. Myself and other golds will check this thread and update information as needed.
-30
30Hertz on 06/5/2007 13:04:10
Your going to need to redesign your enclosure. I can tell just by looking at it that its not near the ^ft needed for the MOFO alone.
Also, the 6x9 CAN NOT share the same chamber as the subwoofers. It needs to have a seperate area to be installed in, not in the same enclosure. You could probably just not use it =).
Can u take a pic of the port?
chrisrohit123 on 06/5/2007 13:15:21
The legacy amp specs are
SKU: SALA2268
Mfg SKU #: LA2268
Brand: LEGACY
Condition: Brand New
Description
· 2000 Watts x 2 Output
· 4000 Watts x 1 Bridged Output
· Variable Hi/Lo Electronic Crossover Network
· Variable Bass Boost
· Variable Input Level (Gain) Control
· MOSFET PWM Power Supply
· Power ON LED Indicator
· LED Protection Indicator
· Remote Bass Boost
· Hi/Lo Impedance Input
· Thermal / Overload / Short Circuit Protection
· Anti-Thump Turn-On
· Dimensions: 1.97'' H x 11.42'' W x 21'' L
The Boss Amp specs are
Product Description: · Class D Monoblock Power Amplifier · 900 watts @ 4 Ohms RMS / 2500 watts Max Power · Chrome Plated RCA Inputs / Outputs · Variable Gain Control · Input Sensitivity Selector · LED Power and Protection Indicators · Signal-to-Noise Ratio: <100dB · Variable 24 dB Low Pass Crossover · Variable 0 to +18 dB Bass Boost Control · Remote Subwoofer Level Control · Phase Shift Selector · Dimensions: L12-1/2" x W9-3/8" x H2-5/8 · 1-year Manufacturer's warranty Amplifier Specifications:· Number of Channels: 1 - Mono · RMS Power (4 ohms): 900 watts x 1 chan. · RMS Power (2 ohms): 1500 watts x 1 chan. · RMS Power (1 ohm): Not Stable · Bridged RMS Power: Not Bridgeable · Peak Power Output: 2500 watts · Min. Impedance Unbridged: 2 ohms · Min. Impedance Bridged: Not Bridgeable · THD @ Rated RMS Power: 0.01% · Speaker Level Inputs: No · Amp Preamp Outputs: Yes - 1 Pair · Built-in Crossover: Yes - LP · High-Pass Crossover: N/A · Low-Pass Crossover: 50 - 150Hz · Subsonic Filter: 15 - 40Hz · Signal-to-Noise Ratio: 100 dB · Channel Separation: N/A · Bass Boost: 0 - 18 dB · Bass/Gain Remote: Yes · Fan Cooled: N/A · Fuse Rating: 25A x 3 · Warranty: 1-year Manufacturer's
The Power Acoustic Mofo –15 15” are
2600 watts power handling/1500W RMS
340 oz. magnet
4" BASV / Kapton Hybrid 18 AWG Voice Coil
SPL 92 dB
Ported box: 3.4 Ft³
Tuning: 40 Hz
Port size: 4" x 10"
Number of ports: 2
Non-pressed paper cone with aluminum rib insert (patent pending)
Dual 2ohm voice coil
Die cast aluminum
Wrinkle finish front & back plate
Large foam rubber surround
1-piece Rubber gasket
Dual Conex spider
Woven tinsel lead through spider
Chrome screw terminals
http://cgi.ebay.com/POWER-ACOUSTIK-MOFO-15-15-2600-WATT-SUBWOOFER-NEW-SUB_W0QQitemZ250117018721QQihZ015QQcategoryZ18804QQrdZ1QQssPageNameZWD1VQQcmdZViewItem
the capacitors spec is
Capacitance: 5.000,000 micro farad
(5.0 FARAD )
Working Voltage: 12DC(works on 0 to 24 volt)
Surge Voltage: 24DC
Equivalent Series Resistance: 0.0015 ohm @ 120hz/25 C
Capacitance Tolerance: +- 10%
charging bulb and mounts
The rest im still getting together
chrisrohit123 on 06/5/2007 13:30:11
Everything is built in one chamber. one port. If i redesign it can u guys help me with a better design cause i did everything without a lot of knowlegde but now i see a lot of flaws mainly to the build of the box. I spent lots of money in the fiberglass material and labor. Can u give me a example of how the box should be build with just mdf and ported. I think i will just do that instead. But wat will i do with this now or is thier any speaker that would be good for use
30Hertz on 06/5/2007 13:32:34
I can help you, i still need to know what impendance the amp is stable bridged and if its Max power or RMS ratings. My gut feeling is its max power
chrisrohit123 on 06/5/2007 13:38:13
The boss amp is 1500 watt rms at 2 ohms and i think that what i have them at. I will update you with the pictures very soon
chrisrohit123 on 06/5/2007 13:54:12
Heres some pics of the port
http://i196.photobucket.com/albums/aa80/chrisrohit123/DSC00084.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/DSC00087.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/DSC00086.jpg
kirchatndftbl on 06/5/2007 16:10:02
anyone think it might be better to just run the mofo in a ported box built to the sub specs???? instead of mixing subs
just my opinion
swez on 06/5/2007 18:28:40
What is the fuse rating on that Legacy LA2268? Depending on your answer, this amp paired with the MOFO sub, may be your best bet.
I hate to be the bearer of bad news, (Truth telling means a better result) but you might be better off dropping to a single 15" sub in a properly designed ported enclosure. The MOFO 15" can be wired for 1 or 4 ohms and is rated at 1500 watts RMS. This is a solid sub and it may be your best bet. It is not well suited to that Boss Amp as this amp is not 1 ohm stable and only 900 watts RMS @ 4 ohms. (Not too bad, but leaving 30% power short will not get the full potential from this sub)
Do you have a good link to the Alphasonic(k) woofer specs? That would be most helpful.
As for wiring your main power line for all amps used, a 1/0 gage line would be your best bet. Then split to appropriate gage lines for the amps you will use. (#2 gage line is very hard to find these days and a pile of 4 gage lines of this length would be a real mess to work with)
A #4 gage line at say 20 feet is relable at 20 feet or less and can deliver ~80 amps well at this length or shorter. Once we go longer on a #4 line, resistance in that line is larger and voltage drops can be an issue for high current draw amps.
It's unfortunate you did not find CK sooner. We could have saved you a lot of "do-over" work and expense. But, am glad you found us anyway. We can help you reboot and come to a solid system design you can really enjoy later. COFFEE
Yes, this will be a major do-over in the short-term. However, it's better to do the work over and maximize what you now have and build off that success later.
Swez
PS Explorer Sport? That's the door version right? Do you know the stock ALT specs on this one? I hope it has a towing package and a 140A ALT. If not, the "Big 3" wiring upgrade will help to some degree, but so will optimizing what you already have.
PSS Am not being negative toward what has been done in earnest to date. There are a number of things we can lead you through that will make you proud of the outcome later. Yes, a simlified MDF ported box is fine and a lot less hassle to fabricate. We'll guide you through the re-work process as needed. USFLAG
Neither amp noted, (Legacy or Boss) are quality amps that can take the punishment over the long haul. It is also not advised to mix subs in the same enclosure w/o careful considerations to enclosure design and adequate power to each sub.
chrisrohit123 on 06/5/2007 21:37:44
There is a specific box i was looking at which may really help. Here are the specs.
Precision Constructed with MDF
Grey Carpeted Box for added protection
Dimensions 16 1/2" Height X 21 1/2" Width X 18" Depth
3.4 Cu. Ft. Per Chamber
Includes (1) Built-In Speaker Terminals
Single 15" Vented Box
http://cgi.ebay.com/SINGLE-15-SUBWOOFER-VENTED-PORTED-ENCLOSURE-SUB-BOX-U_W0QQitemZ140125663877QQihZ004QQcategoryZ50568QQrdZ1QQcmdZViewItem
and the alphasonik speaker spec is
PSW415
15” ALPHA 400 SERIES SUBWOOFER
Heavy Gauge Stamped Steel Chrome Plated “Alpha” Basket
Motor Assembly Heat Sink
High Rigidity Inverted Dome Mineral-Filled Composite Cone
EPDM Surround for Enhanced Control at Extreme Temperatures
Flat Progressive Rate Nomex® Damper w/ Spiral-Woven Leads
8-Gauge Lug-Lock Input Terminals
Rated at 600 Watts RMS
93dB Efficiency
Frequency Response of
25Hz to 500Hz
51 oz. Double-Stacked Magnet
Dual 4-ohm 2” Voice Coils
Mounting Dimensions
Depth: 6 1/2”
Through Hole: 14”
Diameter: 15 1/2”
http://www.alphasonik.com/400.html
WHat should i do now ? should i use the specs on the box appove and build a box out of mdf, to hold both of the subs.? Im thinking of scrapping the fiberglass box. Making a new box with thier own chambers and port. ALso Swez, 30 Hertz or someone please make a diagram or show me a layout of how the box should be made to make both speakers efficent. i need a layout of what i should atleast abide by.
trunkisloud on 06/5/2007 21:57:58
you "could" get a pre-fab box such as the one noted above....but you can get better results with a box built to spec for your sub with maybe a little tweaking on the dimensions. if you want to run 2 15's maybe you should look into another mofo....matching subs would make things a lot easier.....probably could afford to ditch some equipment here as well ....that would take stress off the electrical equip.....and as mentioned above the amps here are not really up to par for the mofo....you can get better quality for decent price online......
swez on 06/5/2007 22:39:20
If you are determined to use both subs, it is possible with some very carefull planning.
The Alphasonik sub enclosure specs are noted here:
http://www.alphasonik.com/images/tech/400%20Series%20Parameters.pdf
This sub is rated at 600 watts RMS and can be used in a ported chamber with it's own tuning ports. The best amp to use for this one is your Boss Amp. Unfortunately, the Boss amp is rated at 1500 watts RMS @ 2 ohms, 900 watts @ 4 ohms and perhaps 500-600 watts @ 8 ohms.
Your only options with this sub are 2 or 8 ohms from this Boss amp. At 2 ohms, you'll have to be very careful on gain setting this amp so you don't blow the sub apart. It would be safe to run it at 8 ohms and the sub should survive.
The MOFO sub is your strongest sub and can do a pretty good job off the Boss amp when wired at 4 ohms. It's not the most efficient way to use this amp or MOFO sub, but it would work .
Tech Tip: It is better to run one strong sub to the best potential a given amp can deliver. Mixing subs of different brands and specs is a crap shoot that only an advanced tech should even consider. In a well optimized system, often times, "less is indeed more".
In this senario, neither subs are matched and the amps mentioned are not optimal for either sub. Your strongest amp seems to be the Boss amp when mated to a 2 ohm load. However, based on what you have on hand and the specs we know about, the best choice here is the MOFO @ 4 ohms, mated to your Boss amp.
I still cannot find any useful infomation about that Legacy 2 channel amp mentioned. If we knew the fuses used in it, we could estimate the potential RMS power you can expect from it at 2-4 ohms. Do you know the fuse values in this amp?
This sub box mentioned earlier is a good fit for your Alphasonik sub. If we knew the port dimensions, it would help give us a better handle on what kind of bass to ecpect. The specs on the box DO NOT include port dimensions or tuning range.
This box is also well suited to the MOFO 15" sub. The recommended port tuning is 40 Hz. Here again, w/o knowing the box port specs, we are left to a degree of hit and miss scenarios. (I would probably consider using this box for either sub and experiment with the Subsonic amp filters for best results) It would be a good idea to contact the seller and ask what the approximate port tuning specs would be.
If you are deterimined to use both amps and subs, it does look like the box mentioned from e-bay would be a good option for both subs. However, it will require some very careful matching of amp power to each sub so they sound about the same. It can be done and the best way would be to have each amp/sub tested for SPL numbers to match each amps gain settings and SPL #'s from each sub independently.
How does that sound to you?
Swez
chrisrohit123 on 06/5/2007 23:37:13
WHat amp on ebay or a good website would be best for the MOFO?
kirchatndftbl on 06/6/2007 00:26:51
http://www.sonicelectronix.com/item_6336_Hifonics+BXi+1606D.html
the bxi1606D would be a good match rated at 1600RMS @ 1ohm
pretty good price on it too
chrisrohit123 on 06/6/2007 02:59:50
i WAS THINKING OF A NEW DESIGN WHICH I JUST THOUGHT IT COULD POSSIBLY WORK. i AM A FLOORS MAN AND I DEALT WITH WOOD ALL MY LIFE SINCE SEEING FIBERGLASS SUBS. I ALWAYS WANTED TO KNOW HOW TO DO SOMETHING LIKE THAT. BUT THE NEW DESIGN WILL ACCOMODATE THE FIBERGLASS AND MDF WOOD.
THE SPECS IS 50(W) X17(H) X 21(D)
29.5(W) FOR THE MOFO AND 20.5(W) FOR THE ALPHASONIK
L PORT. I THINK THATS THE WAY IT MAY BE SAID. ALSO I NEED HELP WITH PORTING IT AND HOW TO AND WHATS BEST. I DREW A LITTLE DIAGRAM OF POSSIBLE BLUE PRINTS. PLEASE WRITE SWEZ, 30 HERTZ, EVERYONE
http://i196.photobucket.com/albums/aa80/chrisrohit123/RICOBOXREVISE2.jpg
chrisrohit123 on 06/6/2007 03:02:53
THE BOTTOM AND BACK AND EVEN BACK WILL HAVE AMPS AND ALL THE STUFF ON THE TRUCK PLACED ON IT
30Hertz on 06/6/2007 03:25:52
I'll look at this tomorrow. Its been a long day and a late night.
My personal suggestion...Ditch one of the 15s and go with a single 15" Sub. I have personally used the 12" MoFo and it wanged nicely. Throw about 1800watts to it ported and you'll be happy with the performance.
In my opinion, the extra sub , and design isnt worth the hassle. Its not going to provide a very good return on your investment. (IE. $$, Time, Labor etc)
chrisrohit123 on 06/6/2007 03:29:22
tHE STOCK ALTERNATOR IS 130 AMP. SHOULD I GET A 200AMP ALTERNATOR. I THINK I WILL DO THE BIG THREE FIRST THEN IF IT STILL NOT AS GOOD AS I THOUGHT, THEN CHANGE THE ALTERNATOR. aLSO RUN A 1/0 GAUGE WIRE FROM FRONT BATTERY TO BACK. DISTRIBUTOR BLOCK TO THREE 4 GUAGE. USE THE SAME GROUND POINT
chrisrohit123 on 06/6/2007 16:55:58
Guys need help. SWEZ. 30 HERTZZ. I will probaly make a box. similar to the box above and how do you tune the box?
swez on 06/6/2007 18:41:27
Chris,
I am having a little "heartburn" on this project when mixing subs and amps like this. After doing car audio for almost 9 years and Pro/Commercial for another 10 + years. Based on that, I cannot in good conscience, advocate or assist in this phase of the project as is.
You are on the right track with wiring ideas and perhaps an electrical upgrade or 2 as mentioned. Mixing amps and subs as mentioned before. However, I choose not to work in this direction and see it fail with my good name and reputation on the line. (Have been at this too long and know when it's time to bow out)
It's your gig and choice to do as your like. (No problem as it's on your time and your dime) But look at the results so far... built a fiberglass box that does not work, using poorly matched gear and not taking subtle yet direct input from 30 Hz and me, but not listening to solid advice. In my books, that's a deal breaker and I elect to beg off.
Swez COFFEE
PS I am not upset, angry or any such thing with you or your choices. I just choose not to participate. Best of luck as you go froward OK...
kirchatndftbl on 06/6/2007 20:34:52
what they are trying to say is the mofo sub will perform extremely well by itself and the alphasonic might actually only make the system sound worse with cancelation and the design of both subs are different which produce different sounds
try the single mofo by itself n if its not enough for you ad another one
ps swez and 30 hertz no there stuff n have been in the business for a while so i would personally take their advice
chrisrohit123 on 06/6/2007 21:11:42
I will stick to the single 15" sub. The mofo is the best match. And with wiring i will most likely use the boss. Is it possible i can use the boss and the legacy for added power. or just stick with the boss amp. SO i will build a 3.4 cu ft box to work with the mofo and the boss amp + capacitor.
cplkittle on 06/6/2007 23:00:53
You can only use one amplifier. In rare cases, two may be used, but they have to be the same brand, same model, and carefully adjusted with a multimeter for identical output.
You made the right choice going with only one 15. I think you will be very happy with your choice.
Your enclosure can be made of whatever you want to make it with, as long as the sides don't flex and it is airtight (minus the port, of course). After you build the box and you are happy with the results sound wise, you can add to it, dress it up, add amp racks, fiberglass. This is how we do competition audio. Build a box, test it out, make changes, then make it pretty.
newB on 06/7/2007 03:03:37
dangit i missed 90% of this thread!
-Drew
Replies (29)
chrisrohit123 on 06/5/2007 01:07:11
2001 FOrd Explorer sport. I think its the wire i invest money for the 4gauge wire and i think i need 0-2 guage because of the length of my suv.
newB on 06/5/2007 02:06:55
i think i follow.
now- i would look into several things.
voltage drop may be an issue, depending on the stock electrical i would recomend running your big 3 under the hood with extra 4ga. a bigger power wire always helps and if you do decide to upgrade you can use your old 4ga for the "under the hood" upgrade.
also consider this fiberglass box. the way the woofer(s) behave depends on the enviroment they are placed into. how are they ported? areo port?
what is the tuning frequency?
and net internal volume of the box?
check things like phase as well
let us know and keep us posted
-Drew
chrisrohit123 on 06/5/2007 12:35:57
I don't understand the part you said "running your big 3 under the hood" that part i dont really understand. I have a 3 way crossover with a phase. The port is facing the outside or the opposite of the speaker. Facing the truck wall. I also was thinking maybe i need a better alternator. I just changed the battery terminal which has one 0 gauge one 4 gauge and two 8 gauge. I used the three four gauge in the 0 guage which barely fits. The 4 gauge was used for the car wires. I am going to get a better terminal as soon as i get more funds.What do u suggest for a good terminal to accomodate my wire setup. DO you think upgrading to better alternator and 0-2 gauge wires will help significantly. Also i used the subwoofer output from the head unit which is a JVC KD-G725. has a usb input which is great and it 50w x4. I really want this thing to sound good because i had the alphasonik first originally installed and that speaker sounded nice with just the legacy predator amp and the capacitor. Now with all this stuff its sounded like a waste of my time. FIxing from morning untill night. Now im having second guesses since my results are not expected to be. Please help with your advice.
chrisrohit123 on 06/5/2007 12:56:10
heres some pics i took today.
chrisrohit123 on 06/5/2007 12:58:10
Heres some pics
http://i196.photobucket.com/albums/aa80/chrisrohit123/1st.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/electsetup.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/Box1.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/Crossover.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/SIde.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/batteery.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/Batteryposterminal.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/DSC00072.jpg
30Hertz on 06/5/2007 13:00:43
Pictures here would speak a thousand words. We
We also need more information on your equipment. We need Model Numbers, and more specifications on your subwoofers.
What is the exact model number for your Legacy predator? I've looked at for the specs and from every website I gather, its 4000watts MAX POWER bridged but does not give you an Ohm load that it can handle for bridging. The marketing for this amplifier is shady at best.
What is the voice coil configuration for your subwoofers? Are they Dual Voice Coil (DVC) and what OHMS are they? 2, 4 ?
We generally prefer to not mix subwoofer brands due to the fact that T/S parameters vary from make to make and model to model which can affect performance if both are in a single chambered enclosure.
You say you have a 6x9 also in the panel, is this built into the enclosure so its sharing the same airspace as the subwoofers? Or is it in its own seperate compartment away from the subs?
Why did you run multiple runs of 4guage wire? A single run of 1/0 guage would be fine here. Generally we need to have the same size wire going to the ground as we would for the power, installing multiple runs of 4 guage with only 1 run of 4guage ground doesnt fit the bill but will probably work.
I dont see voltage drop really being the culprit here in your lack of wangage.
My gut feeling is telling me 2 things here. A. Your enclosure isnt built correctly for these subs and B. Your lacking in the power department.
What is the total ^ft of your enclosure? I've run the 12" Power Acoustik MOFOs and they are an airspace hungry woofer. A single 12 needed 3^ft and could only be run ported. The 15 would most likely require more. Are both subs installed sharing a single chamber? or is it a dual chambered box?
What size port do you have installed and what is it tuned to?
This is enough for now. Plz respond with the information requested. Myself and other golds will check this thread and update information as needed.
-30
30Hertz on 06/5/2007 13:04:10
Your going to need to redesign your enclosure. I can tell just by looking at it that its not near the ^ft needed for the MOFO alone.
Also, the 6x9 CAN NOT share the same chamber as the subwoofers. It needs to have a seperate area to be installed in, not in the same enclosure. You could probably just not use it =).
Can u take a pic of the port?
chrisrohit123 on 06/5/2007 13:15:21
The legacy amp specs are
SKU: SALA2268
Mfg SKU #: LA2268
Brand: LEGACY
Condition: Brand New
Description
· 2000 Watts x 2 Output
· 4000 Watts x 1 Bridged Output
· Variable Hi/Lo Electronic Crossover Network
· Variable Bass Boost
· Variable Input Level (Gain) Control
· MOSFET PWM Power Supply
· Power ON LED Indicator
· LED Protection Indicator
· Remote Bass Boost
· Hi/Lo Impedance Input
· Thermal / Overload / Short Circuit Protection
· Anti-Thump Turn-On
· Dimensions: 1.97'' H x 11.42'' W x 21'' L
The Boss Amp specs are
Product Description: · Class D Monoblock Power Amplifier · 900 watts @ 4 Ohms RMS / 2500 watts Max Power · Chrome Plated RCA Inputs / Outputs · Variable Gain Control · Input Sensitivity Selector · LED Power and Protection Indicators · Signal-to-Noise Ratio: <100dB · Variable 24 dB Low Pass Crossover · Variable 0 to +18 dB Bass Boost Control · Remote Subwoofer Level Control · Phase Shift Selector · Dimensions: L12-1/2" x W9-3/8" x H2-5/8 · 1-year Manufacturer's warranty Amplifier Specifications:· Number of Channels: 1 - Mono · RMS Power (4 ohms): 900 watts x 1 chan. · RMS Power (2 ohms): 1500 watts x 1 chan. · RMS Power (1 ohm): Not Stable · Bridged RMS Power: Not Bridgeable · Peak Power Output: 2500 watts · Min. Impedance Unbridged: 2 ohms · Min. Impedance Bridged: Not Bridgeable · THD @ Rated RMS Power: 0.01% · Speaker Level Inputs: No · Amp Preamp Outputs: Yes - 1 Pair · Built-in Crossover: Yes - LP · High-Pass Crossover: N/A · Low-Pass Crossover: 50 - 150Hz · Subsonic Filter: 15 - 40Hz · Signal-to-Noise Ratio: 100 dB · Channel Separation: N/A · Bass Boost: 0 - 18 dB · Bass/Gain Remote: Yes · Fan Cooled: N/A · Fuse Rating: 25A x 3 · Warranty: 1-year Manufacturer's
The Power Acoustic Mofo –15 15” are
2600 watts power handling/1500W RMS
340 oz. magnet
4" BASV / Kapton Hybrid 18 AWG Voice Coil
SPL 92 dB
Ported box: 3.4 Ft³
Tuning: 40 Hz
Port size: 4" x 10"
Number of ports: 2
Non-pressed paper cone with aluminum rib insert (patent pending)
Dual 2ohm voice coil
Die cast aluminum
Wrinkle finish front & back plate
Large foam rubber surround
1-piece Rubber gasket
Dual Conex spider
Woven tinsel lead through spider
Chrome screw terminals
http://cgi.ebay.com/POWER-ACOUSTIK-MOFO-15-15-2600-WATT-SUBWOOFER-NEW-SUB_W0QQitemZ250117018721QQihZ015QQcategoryZ18804QQrdZ1QQssPageNameZWD1VQQcmdZViewItem
the capacitors spec is
Capacitance: 5.000,000 micro farad
(5.0 FARAD )
Working Voltage: 12DC(works on 0 to 24 volt)
Surge Voltage: 24DC
Equivalent Series Resistance: 0.0015 ohm @ 120hz/25 C
Capacitance Tolerance: +- 10%
charging bulb and mounts
The rest im still getting together
chrisrohit123 on 06/5/2007 13:30:11
Everything is built in one chamber. one port. If i redesign it can u guys help me with a better design cause i did everything without a lot of knowlegde but now i see a lot of flaws mainly to the build of the box. I spent lots of money in the fiberglass material and labor. Can u give me a example of how the box should be build with just mdf and ported. I think i will just do that instead. But wat will i do with this now or is thier any speaker that would be good for use
30Hertz on 06/5/2007 13:32:34
I can help you, i still need to know what impendance the amp is stable bridged and if its Max power or RMS ratings. My gut feeling is its max power
chrisrohit123 on 06/5/2007 13:38:13
The boss amp is 1500 watt rms at 2 ohms and i think that what i have them at. I will update you with the pictures very soon
chrisrohit123 on 06/5/2007 13:54:12
Heres some pics of the port
http://i196.photobucket.com/albums/aa80/chrisrohit123/DSC00084.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/DSC00087.jpg
http://i196.photobucket.com/albums/aa80/chrisrohit123/DSC00086.jpg
kirchatndftbl on 06/5/2007 16:10:02
anyone think it might be better to just run the mofo in a ported box built to the sub specs???? instead of mixing subs
just my opinion
swez on 06/5/2007 18:28:40
What is the fuse rating on that Legacy LA2268? Depending on your answer, this amp paired with the MOFO sub, may be your best bet.
I hate to be the bearer of bad news, (Truth telling means a better result) but you might be better off dropping to a single 15" sub in a properly designed ported enclosure. The MOFO 15" can be wired for 1 or 4 ohms and is rated at 1500 watts RMS. This is a solid sub and it may be your best bet. It is not well suited to that Boss Amp as this amp is not 1 ohm stable and only 900 watts RMS @ 4 ohms. (Not too bad, but leaving 30% power short will not get the full potential from this sub)
Do you have a good link to the Alphasonic(k) woofer specs? That would be most helpful.
As for wiring your main power line for all amps used, a 1/0 gage line would be your best bet. Then split to appropriate gage lines for the amps you will use. (#2 gage line is very hard to find these days and a pile of 4 gage lines of this length would be a real mess to work with)
A #4 gage line at say 20 feet is relable at 20 feet or less and can deliver ~80 amps well at this length or shorter. Once we go longer on a #4 line, resistance in that line is larger and voltage drops can be an issue for high current draw amps.
It's unfortunate you did not find CK sooner. We could have saved you a lot of "do-over" work and expense. But, am glad you found us anyway. We can help you reboot and come to a solid system design you can really enjoy later. COFFEE
Yes, this will be a major do-over in the short-term. However, it's better to do the work over and maximize what you now have and build off that success later.
Swez
PS Explorer Sport? That's the door version right? Do you know the stock ALT specs on this one? I hope it has a towing package and a 140A ALT. If not, the "Big 3" wiring upgrade will help to some degree, but so will optimizing what you already have.
PSS Am not being negative toward what has been done in earnest to date. There are a number of things we can lead you through that will make you proud of the outcome later. Yes, a simlified MDF ported box is fine and a lot less hassle to fabricate. We'll guide you through the re-work process as needed. USFLAG
Neither amp noted, (Legacy or Boss) are quality amps that can take the punishment over the long haul. It is also not advised to mix subs in the same enclosure w/o careful considerations to enclosure design and adequate power to each sub.
chrisrohit123 on 06/5/2007 21:37:44
There is a specific box i was looking at which may really help. Here are the specs.
Precision Constructed with MDF
Grey Carpeted Box for added protection
Dimensions 16 1/2" Height X 21 1/2" Width X 18" Depth
3.4 Cu. Ft. Per Chamber
Includes (1) Built-In Speaker Terminals
Single 15" Vented Box
http://cgi.ebay.com/SINGLE-15-SUBWOOFER-VENTED-PORTED-ENCLOSURE-SUB-BOX-U_W0QQitemZ140125663877QQihZ004QQcategoryZ50568QQrdZ1QQcmdZViewItem
and the alphasonik speaker spec is
PSW415
15” ALPHA 400 SERIES SUBWOOFER
Heavy Gauge Stamped Steel Chrome Plated “Alpha” Basket
Motor Assembly Heat Sink
High Rigidity Inverted Dome Mineral-Filled Composite Cone
EPDM Surround for Enhanced Control at Extreme Temperatures
Flat Progressive Rate Nomex® Damper w/ Spiral-Woven Leads
8-Gauge Lug-Lock Input Terminals
Rated at 600 Watts RMS
93dB Efficiency
Frequency Response of
25Hz to 500Hz
51 oz. Double-Stacked Magnet
Dual 4-ohm 2” Voice Coils
Mounting Dimensions
Depth: 6 1/2”
Through Hole: 14”
Diameter: 15 1/2”
http://www.alphasonik.com/400.html
WHat should i do now ? should i use the specs on the box appove and build a box out of mdf, to hold both of the subs.? Im thinking of scrapping the fiberglass box. Making a new box with thier own chambers and port. ALso Swez, 30 Hertz or someone please make a diagram or show me a layout of how the box should be made to make both speakers efficent. i need a layout of what i should atleast abide by.
trunkisloud on 06/5/2007 21:57:58
you "could" get a pre-fab box such as the one noted above....but you can get better results with a box built to spec for your sub with maybe a little tweaking on the dimensions. if you want to run 2 15's maybe you should look into another mofo....matching subs would make things a lot easier.....probably could afford to ditch some equipment here as well ....that would take stress off the electrical equip.....and as mentioned above the amps here are not really up to par for the mofo....you can get better quality for decent price online......
swez on 06/5/2007 22:39:20
If you are determined to use both subs, it is possible with some very carefull planning.
The Alphasonik sub enclosure specs are noted here:
http://www.alphasonik.com/images/tech/400%20Series%20Parameters.pdf
This sub is rated at 600 watts RMS and can be used in a ported chamber with it's own tuning ports. The best amp to use for this one is your Boss Amp. Unfortunately, the Boss amp is rated at 1500 watts RMS @ 2 ohms, 900 watts @ 4 ohms and perhaps 500-600 watts @ 8 ohms.
Your only options with this sub are 2 or 8 ohms from this Boss amp. At 2 ohms, you'll have to be very careful on gain setting this amp so you don't blow the sub apart. It would be safe to run it at 8 ohms and the sub should survive.
The MOFO sub is your strongest sub and can do a pretty good job off the Boss amp when wired at 4 ohms. It's not the most efficient way to use this amp or MOFO sub, but it would work .
Tech Tip: It is better to run one strong sub to the best potential a given amp can deliver. Mixing subs of different brands and specs is a crap shoot that only an advanced tech should even consider. In a well optimized system, often times, "less is indeed more".
In this senario, neither subs are matched and the amps mentioned are not optimal for either sub. Your strongest amp seems to be the Boss amp when mated to a 2 ohm load. However, based on what you have on hand and the specs we know about, the best choice here is the MOFO @ 4 ohms, mated to your Boss amp.
I still cannot find any useful infomation about that Legacy 2 channel amp mentioned. If we knew the fuses used in it, we could estimate the potential RMS power you can expect from it at 2-4 ohms. Do you know the fuse values in this amp?
This sub box mentioned earlier is a good fit for your Alphasonik sub. If we knew the port dimensions, it would help give us a better handle on what kind of bass to ecpect. The specs on the box DO NOT include port dimensions or tuning range.
This box is also well suited to the MOFO 15" sub. The recommended port tuning is 40 Hz. Here again, w/o knowing the box port specs, we are left to a degree of hit and miss scenarios. (I would probably consider using this box for either sub and experiment with the Subsonic amp filters for best results) It would be a good idea to contact the seller and ask what the approximate port tuning specs would be.
If you are deterimined to use both amps and subs, it does look like the box mentioned from e-bay would be a good option for both subs. However, it will require some very careful matching of amp power to each sub so they sound about the same. It can be done and the best way would be to have each amp/sub tested for SPL numbers to match each amps gain settings and SPL #'s from each sub independently.
How does that sound to you?
Swez
chrisrohit123 on 06/5/2007 23:37:13
WHat amp on ebay or a good website would be best for the MOFO?
kirchatndftbl on 06/6/2007 00:26:51
http://www.sonicelectronix.com/item_6336_Hifonics+BXi+1606D.html
the bxi1606D would be a good match rated at 1600RMS @ 1ohm
pretty good price on it too
chrisrohit123 on 06/6/2007 02:59:50
i WAS THINKING OF A NEW DESIGN WHICH I JUST THOUGHT IT COULD POSSIBLY WORK. i AM A FLOORS MAN AND I DEALT WITH WOOD ALL MY LIFE SINCE SEEING FIBERGLASS SUBS. I ALWAYS WANTED TO KNOW HOW TO DO SOMETHING LIKE THAT. BUT THE NEW DESIGN WILL ACCOMODATE THE FIBERGLASS AND MDF WOOD.
THE SPECS IS 50(W) X17(H) X 21(D)
29.5(W) FOR THE MOFO AND 20.5(W) FOR THE ALPHASONIK
L PORT. I THINK THATS THE WAY IT MAY BE SAID. ALSO I NEED HELP WITH PORTING IT AND HOW TO AND WHATS BEST. I DREW A LITTLE DIAGRAM OF POSSIBLE BLUE PRINTS. PLEASE WRITE SWEZ, 30 HERTZ, EVERYONE
http://i196.photobucket.com/albums/aa80/chrisrohit123/RICOBOXREVISE2.jpg
chrisrohit123 on 06/6/2007 03:02:53
THE BOTTOM AND BACK AND EVEN BACK WILL HAVE AMPS AND ALL THE STUFF ON THE TRUCK PLACED ON IT
30Hertz on 06/6/2007 03:25:52
I'll look at this tomorrow. Its been a long day and a late night.
My personal suggestion...Ditch one of the 15s and go with a single 15" Sub. I have personally used the 12" MoFo and it wanged nicely. Throw about 1800watts to it ported and you'll be happy with the performance.
In my opinion, the extra sub , and design isnt worth the hassle. Its not going to provide a very good return on your investment. (IE. $$, Time, Labor etc)
chrisrohit123 on 06/6/2007 03:29:22
tHE STOCK ALTERNATOR IS 130 AMP. SHOULD I GET A 200AMP ALTERNATOR. I THINK I WILL DO THE BIG THREE FIRST THEN IF IT STILL NOT AS GOOD AS I THOUGHT, THEN CHANGE THE ALTERNATOR. aLSO RUN A 1/0 GAUGE WIRE FROM FRONT BATTERY TO BACK. DISTRIBUTOR BLOCK TO THREE 4 GUAGE. USE THE SAME GROUND POINT
chrisrohit123 on 06/6/2007 16:55:58
Guys need help. SWEZ. 30 HERTZZ. I will probaly make a box. similar to the box above and how do you tune the box?
swez on 06/6/2007 18:41:27
Chris,
I am having a little "heartburn" on this project when mixing subs and amps like this. After doing car audio for almost 9 years and Pro/Commercial for another 10 + years. Based on that, I cannot in good conscience, advocate or assist in this phase of the project as is.
You are on the right track with wiring ideas and perhaps an electrical upgrade or 2 as mentioned. Mixing amps and subs as mentioned before. However, I choose not to work in this direction and see it fail with my good name and reputation on the line. (Have been at this too long and know when it's time to bow out)
It's your gig and choice to do as your like. (No problem as it's on your time and your dime) But look at the results so far... built a fiberglass box that does not work, using poorly matched gear and not taking subtle yet direct input from 30 Hz and me, but not listening to solid advice. In my books, that's a deal breaker and I elect to beg off.
Swez COFFEE
PS I am not upset, angry or any such thing with you or your choices. I just choose not to participate. Best of luck as you go froward OK...
kirchatndftbl on 06/6/2007 20:34:52
what they are trying to say is the mofo sub will perform extremely well by itself and the alphasonic might actually only make the system sound worse with cancelation and the design of both subs are different which produce different sounds
try the single mofo by itself n if its not enough for you ad another one
ps swez and 30 hertz no there stuff n have been in the business for a while so i would personally take their advice
chrisrohit123 on 06/6/2007 21:11:42
I will stick to the single 15" sub. The mofo is the best match. And with wiring i will most likely use the boss. Is it possible i can use the boss and the legacy for added power. or just stick with the boss amp. SO i will build a 3.4 cu ft box to work with the mofo and the boss amp + capacitor.
cplkittle on 06/6/2007 23:00:53
You can only use one amplifier. In rare cases, two may be used, but they have to be the same brand, same model, and carefully adjusted with a multimeter for identical output.
You made the right choice going with only one 15. I think you will be very happy with your choice.
Your enclosure can be made of whatever you want to make it with, as long as the sides don't flex and it is airtight (minus the port, of course). After you build the box and you are happy with the results sound wise, you can add to it, dress it up, add amp racks, fiberglass. This is how we do competition audio. Build a box, test it out, make changes, then make it pretty.
newB on 06/7/2007 03:03:37
dangit i missed 90% of this thread!
-Drew
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