Need help to choose amps and subs

carabuser · 09-23-2003, 06:50 PM

Hey everyone. Although I have been playing w/ my car audio for a while, I still have a few questions for you

Here's the thing, i can't choose between three amps I like to power my 12" L5 Kicker. The choices I have are:
1. PRECISION POWER PCX1250 1 Channel Car Amplifier
2. ROCKFORD FOSGATE 500BD 1 Channel
3. KICKER KX600.1 Mono Car Amplifier-600

My first priority is PPI PCX1250. The reason, well I just like it. Although it only gives you 500W rms, I heard the quality of their sound is pretty good. Second - FOSGATE 500BD. Reason - price, 600W output at 2ohms. Third (and LAST) - kicker. The reason it's the last one is that I already fried one of 'em for, what seemed to me, no reason. Any other amp worked w/ the same setup.

Most likely I will use my sub in a bandpass box (BIG one) on 2ohm.

Also, another question, I have a pair of Kicker 12" CVR's. What do you think will be better, using the two CVRs in bandpass box w/ nice amp, or using the 12"L5 w/ one of the amps above?

Tell me what you guys think, all help is appreciated!

osirisdon · 09-23-2003, 07:59 PM

Overpower that SUB!!!!

Yeah its a crazy recommendation, but im pushing 150w into a 75w sub, and it sounds as good as any single 10 or 12 inch sub. Also in a bandpass box.

I will not give you any specific recommendation, but I sure can recommend you look at the numbers. Wheres the most power? How much does your sub handle? whats the freq response of the amp? and so on.

Again OVER POWER THAT PUPPY.

guitar333 · 09-23-2003, 10:19 PM

I wouldnt over power it, but its hard to tell how much power your exactly giving it because of impedence, wire, voltage differences etc.

the 2 compvr's will sound better than the one l5, IMO

Put the 2 compvr's in a bandpass and use a kickerkx800.2 (400W RMS X 2 @ 2 OHMS) and you will be bumpin.

If not, the amp I recommend for that l5 is the kicker kx600.1 (600W RMS x1 @ 2-ohms), and you will have to get a specially cut bandpass, if you plan to use the L5 (if you dont make your own)

333rd post

carabuser · 09-23-2003, 10:40 PM

Quote: Originally Posted by guitar333

I wouldnt over power it, but its hard to tell how much power your exactly giving it because of impedence, wire, voltage differences etc.

the 2 compvr's will sound better than the one l5, IMO

Put the 2 compvr's in a bandpass and use a kickerkx800.2 (400W RMS X 2 @ 2 OHMS) and you will be bumpin.

If not, the amp I recommend for that l5 is the kicker kx600.1 (600W RMS x1 @ 2-ohms), and you will have to get a specially cut bandpass, if you plan to use the L5 (if you dont make your own)

333rd post

I'm gonna wire the sub as 2 ohms. Why the kicker amp? I used to have (for a week -))) kx600.4, and that one just burnt after I gave it a little load, so I am very carefull about kicker amps now

What size of bandpass box would you recommend for 12" CVR's?

Thanks everyone!

Snootch · 09-26-2003, 07:38 PM

DO NOT USE ANY PRE-BUILT BANDPASS BOXES! They truly are crap. A correctly designed bandpass enclosure will be different for each speaker. Your best bet for clean, powerful bass is a slightly larger than recommended sealed box with lots of power on the sub. Even if you use an amplifier that is capable of twice the rated power that the speaker is capable of, and you set your gain on your amplifier correctly, this extra power gives you headroom during musical peaks, when a smaller amplifier might distort. A ported box is louder than a sealed box, but usually isn't as clean as a sealed setup. Also, a poorly built ported box will blow speakers, as will playing the speaker below the boxes tuning frequency. So basically buy as much power as you can afford, try to keep it balanced between mids/highs and sub, and use a sealed box for sound quality, ported box for loudness, if you just want it loud.

P.S. Maximum sealed box size for the 12 L5 is 2.0 cubes. So put it in 2.075 cubic feet, and power it with 600+ watts of clean power. I assume you are using the dual 2 Ohm L5? I recommend any older than 2000 Rockford Fosgate amp, or also Arc Audio make good, solid amps. IMO the new Rockford amps are crap.

carabuser · 09-26-2003, 09:08 PM

I've had my L5 (it's dual 4ohm that can be wired as 2 ohm or 8 ohm) in a sealed (and a small) box, w/ a weak amp. Didn't like it. Then got two CVR's 12" in a ported box, used the same amp (2 chanels, 240W RMS, i know, weak) and it was louder up until my friend.... got 2 10" kickers (one CVR and one regular) w/ a much weaker amp in a bandpass box and guess what? They DID sound BETTER!!! Was I ****ed off...

Snootch · 09-26-2003, 09:34 PM

Better, or just louder? Most people who get in my car swear that i've got a pair of 12"s or 15"s in it. I have 1 Elemental Designs 12O.44 in .9 Cubic feet, with 500-600 watts RMS on it. One good woofer in a correctly designed box, with loads of power to it, WILL slam, if done correctly. What crossover point/slope are you using? Is it active or passive? The L5 probably as loud as the two 10"s with the same power because with the 10"s you've simply got more cone area.
Possibly your friend was clipping the hell out of his amp to get louder? A bandpass box exhibits a high peak in the 50-70Hz frequencies, but trades off it's low end extension to do this. So it may be louder at certain freq's, but the low end is non-existant. Also, you can't hear a woofer distort in a bandpass enclosure too well.

carabuser · 09-27-2003, 02:40 AM

Quote: Originally Posted by Snootch

Better, or just louder? Most people who get in my car swear that i've got a pair of 12"s or 15"s in it. I have 1 Elemental Designs 12O.44 in .9 Cubic feet, with 500-600 watts RMS on it. One good woofer in a correctly designed box, with loads of power to it, WILL slam, if done correctly. What crossover point/slope are you using? Is it active or passive? The L5 probably as loud as the two 10"s with the same power because with the 10"s you've simply got more cone area.
Possibly your friend was clipping the hell out of his amp to get louder? A bandpass box exhibits a high peak in the 50-70Hz frequencies, but trades off it's low end extension to do this. So it may be louder at certain freq's, but the low end is non-existant. Also, you can't hear a woofer distort in a bandpass enclosure too well.

wasn't really louder, I just liked it better. Plus his amp is not tweaked at all and.
The only crossovers I'm using are the ones on the amp. The amp is Performance Teknique ICBM 779.

ScYThE · 09-27-2003, 08:01 AM

Well, there is another option for your two kicker CVR's. You could build a pressure box. (the two subs in seperate chambers with a 8 inch channel btween them and the speackers facing each other). This is a massive setup, but my friend was using 4 jl 8w0's and was hitting 150-160 db cleanly with a kicker zx360 at 2 ohms. that was pushing about 1100 to the four speakers. Your two tens should be able to do at least that and maybe into the 160's without much distortion. The sealed box will sound better. Also, it takes less power to move diaphrams in a ported box because you are not compressing the air behind the speaker nearly as much, but you dont get the same quality of sound from them.

I am a JL fan, and I personally would recommend a JL 1000 watt amp or mabee even the Crossfire BFA1000 (or is it BFD).
Just my 2 cents

Snootch · 09-27-2003, 01:14 PM

150-160db, with 4 8"s? I'm sorry, but i don't buy it.

What RTA/mic were they using when it was metered? You said two seperate chambers (sealed?) firing into another chamber (ported). --That's a bandpass box.

ScYThE · 09-27-2003, 01:35 PM

he was measured in Phoenix AZ at a db drag comp. The mic was placed on his front dash.

I usually think of band pass boxes having the speakers faceing the same directions, not directly opposing each other. I could be wrong though.

I was there when he had the measurement taken.

OH, the third chamber isnt ported, its more like having only 3 sides. In this case, the port was 9 X 8 in and the chamber was 9 X 8 X 18 if i remember right.

kickercivic1 · 09-27-2003, 03:48 PM

i wounld get anything kicker.. they *****in suck ***.. i had two kx1200 and 2 L715's i kept blowing amps.. and on the top subs can mad hot..i had hx2 in my old civic and i loved it.so if i were i would go with 2 hx2 and 1000bd

Snootch · 09-27-2003, 05:36 PM

Well, the mic must have been really loose. I guess that's pretty cool bragging rights- 160db with 4- 8"s?

Kicker seems to make a good amplifier, I wouldn't know about thier speakers though. I installed a KX700.5 5-channel in my wife's truck, and it's driving 1 set of JL XR 6.5" comps, 1 set Sony Xplod coaxes (rear fill), and a pair of JL 12W0's. It gets pretty loud, and the highs sound good. The amp puts out it's specified power and then some. Currently I'm running older "batwing" style RF amps, and if I had to do it over, i'd use Arc Audio CLR series amps. They seem to be pretty solid.

carabuser · 09-28-2003, 04:03 AM

ok, talked to another guy today and here's what I've decided. Since all of you guys tell me that sealed are the best (well, that's EVERYBODY's telling me) i'll probale go w/ a big sealed box and a mono amp, probably kicker kx600.1. also thinking about two L5's now. We'll see how tight my budget is. And one more thing: I APPRECIATE everybody's suggestions and comments, and if you have any more, I'm more than glad to check them out