PPI Pro124 subs and questions

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hey everyone
Ok, i have a pair of PPI pro 124 12" subs, they are of the flat piston type and handle 300W RMS i think. I have a choice of running the 2 with an alphasonik PMA-2100i (100WRMS@4ohmsx2) or a pioneer GM-X862(125WRMS@4ohmsx2).
Which amp would be a better choice (or should i get an entirely different amp) for these subs, and also does anyone know where to get the thiele small parameters for these drivers or have any box specs, or at least the resonant frequency so i can add a port?

1 more thing, has anyone ever heard or dealt with these subs? are they cool?do they sound good? gimme some ideas!!!
 
Heres the T/S parameters for the PPI pro 124......

Fs = 43 Hz
Qms = 2.51
Vas = 1.553 cu.ft
Cms = 0.0207 in/lb
Mms = 4.046 oz
Rms = 27.53 lb/s
Xmax = 0.217 in
Xmech = 0.512 in
P-Dia = 10.05 in
Sd = 79.36 sq.in
P-Vd = 0.00994 cu.ft
Qes = 0.66
Re = 4 ohms
Z = 4 ohms
BL = 3.089 lb/A
Pe = 300 watts
Qts = 0.52
no = 0.524 %
1-W SPL = 89.31 dB
2.83-V SPL = 92.39 dB

The pro 124 has a pretty high Fs for a 12" sub. I did some box modeling and a 3cu.ft box tuned at 32hz looks ok with a 3db down point of just above 30hz. If you used a single 4" port it would need to be 7" long(a bigger port would be a little better, but it would be much longer). At 300 watts it would yield a vent air velocity of 7.9%. That design is for one side so you would have to double it for both subs.

As far as your choice of amps go, I would look into something with a little more power. Neither of those amps will run those subs to their full potential.
 
Toasty

I have a couple PPI Pro 104's in my big ol' pile of fried woofers. Here are some pics...


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An externally hosted image should be here but it was not working when we last tested it.

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They have very short voice coil lengths and since they are an overhung design they have a very small Xmax. They sounded quite decent at low volume levels but were not SPL demons when cranked. I had a fairly whimpy 300W Autotek class-D amp driving them and the amp was never driven into clipping (I adjust maximum gain with an oscilloscope).

If you're after good sound quality, your two 12's will perform well with either of the amps you listed. If you are going for sheer decibels then you might want to consider a more traditional (less compact) driver.

-Casey Walsh
 
Just a suggestion...... You could get rid of one of those amps and acquire another one that matches the one you decide to keep. Then you can bridge both amps to 4ohm mono and put one sub on each. That should leave you enough headroom to not clip and fry the subs like the pics above.


Good Luck
 
Re: Toasty

SmarmyDog said:
I have a couple PPI Pro 104's in my big ol' pile of fried woofers. Here are some pics...



They have very short voice coil lengths and since they are an overhung design they have a very small Xmax. They sounded quite decent at low volume levels but were not SPL demons when cranked. I had a fairly whimpy 300W Autotek class-D amp driving them and the amp was never driven into clipping (I adjust maximum gain with an oscilloscope).

If you're after good sound quality, your two 12's will perform well with either of the amps you listed. If you are going for sheer decibels then you might want to consider a more traditional (less compact) driver.

-Casey Walsh

Casey,

That Pro10 is not one of the ones Alma agates used is it?


:D
 
Re: Toasty

SmarmyDog said:
I have a couple PPI Pro 104's in my big ol' pile of fried woofers. Here are some pics...


An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.


They have very short voice coil lengths and since they are an overhung design they have a very small Xmax. They sounded quite decent at low volume levels but were not SPL demons when cranked. I had a fairly whimpy 300W Autotek class-D amp driving them and the amp was never driven into clipping (I adjust maximum gain with an oscilloscope).

If you're after good sound quality, your two 12's will perform well with either of the amps you listed. If you are going for sheer decibels then you might want to consider a more traditional (less compact) driver.

-Casey Walsh



ever heard of moderation my god u had to notice the sound if u wrecked them that bad but i bet it was fun!!!!
:eek:
 
Though I'm a lot more of an SQ guy than an SPL guy, I bought one of the 15" Flat Piston PPIs (I'm almost certain it was a Pro series) off uBid for something like $18. It seemed to be a very impressively build sub but even the local shop that carried PPI said they had problems with the 'crazy power' group and these subs... Lots of service was needed and in fact, the one I had for a short time was from some type of repair service center.
 
If you are really into sound quality and quality bass sound, you should check out the Illusion Audio ND12. In a 1.2 cu ft sealed box with about 1 lb of fill, it's absolutely, without a doubt, the best sound quality I've ever heard from a car audio sub.

In the 'much cheaper but still very good' category, I'd put the older Oz audio subs with the holographic diamond logo on the cone (not the dust cap) I think they were the 250L and 300L. The 300L, also in 1.2 cu ft hits pretty hard (not talking loud, but if it's floppy bass, it sounds floppy, but if its low firm bass (such as the big bass drum on several Telarc recordings) it just really hits you and shakes you, moreso than the Illusion really. And the Aura Force series are nice. A Force 12 is what I currently have in my car. It's a little mellower than the Illusion or the Oz subs and is more suited to a lot of what I listen to. I have it in 1.5 cu ft and it's stuffed to the brim with fill. Very happy with the sound and the fact that my fronts are crossed over at ~60 Hz. The sub crossed over just a little higher than that and I'm very happy.
 
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