PPI's new line
0 Watt CAFz'r
Joined: Nov 2003
Posts: 15
If you're looking for good reliable and very efficient amps try DHC 1400 series from MMATS Audio avail;able in .5 - 1 - and 2ohm v ersions
Specifications:
Frequency Response (-3db) 10Hz to 230Hz
Signal to Noise Ratio -92db A weighted
Distortion@Rated Output < 0.1% THD+n
Damping Factor@100Hz >125
Input Sensitivity 150mV to 2.5Vrms
Idle Current 1 amp
Efficiency @ 1/3 Power 72%
Efficiencies over 90%
4 AWG battery inputs
Optimized for low impedance loads
Dual MOSFET power supplies in the HC models
24db low pass Linkwitz-Riley infinitely variable filter
In my opinion some of the best amps ever built
[ January 22, 2004, 12:30 PM: Message edited by: Dragonfly ]
Specifications:
Frequency Response (-3db) 10Hz to 230Hz
Signal to Noise Ratio -92db A weighted
Distortion@Rated Output < 0.1% THD+n
Damping Factor@100Hz >125
Input Sensitivity 150mV to 2.5Vrms
Idle Current 1 amp
Efficiency @ 1/3 Power 72%
Efficiencies over 90%
4 AWG battery inputs
Optimized for low impedance loads
Dual MOSFET power supplies in the HC models
24db low pass Linkwitz-Riley infinitely variable filter
In my opinion some of the best amps ever built
[ January 22, 2004, 12:30 PM: Message edited by: Dragonfly ]
50 Watt CAFz'r
Joined: Mar 2003
Posts: 309
slownlow ... you can't always have the right amp for your subs. I don't really have that much money that I can just replace my entire system at one time. Say I did buy the right amp and now I have a 2 ohm stable amp driving two four ohm loads (final load of 2 ohm). Then I get tired of those subs and get two DVC four ohm subs instead, giving me either a 4 or a 1 ohm load. Look at that!! I either run my amp at half power or below the minimum load and void my warranty. With a 1 ohm stable amp, no problem. That sounds like more flexiblity to me, and it isn't always possible to get dual two ohm coils, either.
And if specs really don't matter, then there actually is no point to getting any amp that costs more then a Sony. So I guess transient response and speaker control count for nothing. Sound quality comp judges know what a good amp sounds like as opposed to a bad one and so do I, and I know that a good amp can be distinguished from a bad amp most generally by looking at specs. If specs really do mean nothing, then what is the point of a premium brand? TRU Technology, Zapco, Xtant, would all be out of business because their wattages are nothing special but they try to raise their damping factors, transient responses, and lower their THD as much as possible for a discerning listener. I think saying specs are worth nothing is just a cheap excuse to justify building a quiet/"SQ" system with MTX, Sony or Power Acoustiks crap.
PPI's amps are in a class of their own as far as damping is concerned. DEI and Lanzar make the only other amps I've ever seen with that low a damping factor. PPI amps are also rated at 14.4 volts, which means their power ratings are inflated. And now, the last season for buying one - great sound quality - seems gone. Transients will be sloppy and out of control, complicated bass lines will sound mushy and layering of sounds just won't be good. Listen to a JL and a PPI on the same subs in the same box and you will be able to tell a difference in how much worse the PPI will sound then the JL, and that difference isn't going to come out of thin air.
[ January 22, 2004, 12:41 PM: Message edited by: Bumpin' Nova ]
And if specs really don't matter, then there actually is no point to getting any amp that costs more then a Sony. So I guess transient response and speaker control count for nothing. Sound quality comp judges know what a good amp sounds like as opposed to a bad one and so do I, and I know that a good amp can be distinguished from a bad amp most generally by looking at specs. If specs really do mean nothing, then what is the point of a premium brand? TRU Technology, Zapco, Xtant, would all be out of business because their wattages are nothing special but they try to raise their damping factors, transient responses, and lower their THD as much as possible for a discerning listener. I think saying specs are worth nothing is just a cheap excuse to justify building a quiet/"SQ" system with MTX, Sony or Power Acoustiks crap.
PPI's amps are in a class of their own as far as damping is concerned. DEI and Lanzar make the only other amps I've ever seen with that low a damping factor. PPI amps are also rated at 14.4 volts, which means their power ratings are inflated. And now, the last season for buying one - great sound quality - seems gone. Transients will be sloppy and out of control, complicated bass lines will sound mushy and layering of sounds just won't be good. Listen to a JL and a PPI on the same subs in the same box and you will be able to tell a difference in how much worse the PPI will sound then the JL, and that difference isn't going to come out of thin air.
[ January 22, 2004, 12:41 PM: Message edited by: Bumpin' Nova ]
500 Watt CAFz'r
Joined: Aug 2001
Posts: 866
Ok, say you have your 2 4ohm subs, and your amp that max's power into 2 ohm. You then get sick of your subs and you go out and buy new ones.
Hey I have an idea " Go out and buy new SVC subs? " and you can still use the same amp. Then when you get sick of your amp, go and get a new amp that produces max power into 2 ohm.
Even if I had 2 dual 4 ohm woofers I would run it at 4 ohm mono, not 1 ohm.
AND I would run it off my crappy MTX amp, and you would here tight accurate bass. Then with the money I saved Id buy new subs
Hey I have an idea " Go out and buy new SVC subs? " and you can still use the same amp. Then when you get sick of your amp, go and get a new amp that produces max power into 2 ohm.
Even if I had 2 dual 4 ohm woofers I would run it at 4 ohm mono, not 1 ohm.
AND I would run it off my crappy MTX amp, and you would here tight accurate bass. Then with the money I saved Id buy new subs
50 Watt CAFz'r
Joined: Mar 2003
Posts: 309
True enough on the Sony. I still have a 1,000 watt monoblock Xplod that I've been running at 1 ohm for a long time now and it holds up just fine. It didn't sound nearly as nice as my JL did, though, even though it's THD is less then one percent. Layering was sloppy and transients were blurry and would pop from time to time, a problem the JL didn't have.
slownlow show me a high end SVC sub.... it happens more and more often with a lot of subs that you can't even get a SVC version. And why would you run your subs at 4 ohm mono? Your subs are less efficient and your amp is running at half power, so unless you are trying to keep from overextending your alt and battery there is no point. Over reference efficiency, you gain 3dB for series wiring and 9dB for parallel, so that is more then 6dB you are just throwing away. I'm not big into buying subs that aren't any better then the ones I already have, so why would I go from an Xmax 4 ohm SVC to say a Thunder8000 4 ohm SVC (which is way worse, anyway)? I would never waste my money like that. If I wanted to step up, I would get good subs, which only come in DVC nowadays, and you can't always get the sub with dual 2 ohm coils either. You haven't made much of a point, yet.
slownlow show me a high end SVC sub.... it happens more and more often with a lot of subs that you can't even get a SVC version. And why would you run your subs at 4 ohm mono? Your subs are less efficient and your amp is running at half power, so unless you are trying to keep from overextending your alt and battery there is no point. Over reference efficiency, you gain 3dB for series wiring and 9dB for parallel, so that is more then 6dB you are just throwing away. I'm not big into buying subs that aren't any better then the ones I already have, so why would I go from an Xmax 4 ohm SVC to say a Thunder8000 4 ohm SVC (which is way worse, anyway)? I would never waste my money like that. If I wanted to step up, I would get good subs, which only come in DVC nowadays, and you can't always get the sub with dual 2 ohm coils either. You haven't made much of a point, yet.
Guest
Posts: n/a
Well since you called me on it I will reply. BTW I am a trained IASCA SQ Judge, and my frame of reference is competition cars such as Scott Buwalda's Altima, Gary Bigg's Regal etc. that I have listened to within the last 6 months.
I have an idea, for IASCA sq they should just add up the specs of the equipment and whoever's is higher is the winner [img]graemlins/freak.gif[/img]
Originally posted by Bumpin' Nova:
And why would you run your subs at 4 ohm mono? Becausethat could be where the amp makes the most power!
Your subs are less efficient and your amp is running at half power, How do the subs know the final load on the amp, their efficiency is unaffected
so unless you are trying to keep from overextending your alt and battery there is no point. Power is power, the battery and alt don't care about the load an the amp.
Over reference efficiency, you gain 3dB for series wiring and 9dB for parallel, so that is more then 6dB you are just throwing away. The wiring has no affect on this equation, it's the power produced by the amp. If an amp goes into protect when paralleled into a load it can't handle it makes zero watt's throwing your observation out the window.
I'm not big into buying subs that aren't any better then the ones I already have, so why would I go from an Xmax 4 ohm SVC to say a Thunder8000 4 ohm SVC (which is way worse, anyway)? worse how? I have seen these subs win IASCA SQ contests
I would never waste my money like that. If I wanted to step up, I would get good subs, which only come in DVC nowadays, and you can't always get the sub with dual 2 ohm coils either. You haven't made much of a point, yet. Neither have you
And why would you run your subs at 4 ohm mono? Becausethat could be where the amp makes the most power!
Your subs are less efficient and your amp is running at half power, How do the subs know the final load on the amp, their efficiency is unaffected
so unless you are trying to keep from overextending your alt and battery there is no point. Power is power, the battery and alt don't care about the load an the amp.
Over reference efficiency, you gain 3dB for series wiring and 9dB for parallel, so that is more then 6dB you are just throwing away. The wiring has no affect on this equation, it's the power produced by the amp. If an amp goes into protect when paralleled into a load it can't handle it makes zero watt's throwing your observation out the window.
I'm not big into buying subs that aren't any better then the ones I already have, so why would I go from an Xmax 4 ohm SVC to say a Thunder8000 4 ohm SVC (which is way worse, anyway)? worse how? I have seen these subs win IASCA SQ contests
I would never waste my money like that. If I wanted to step up, I would get good subs, which only come in DVC nowadays, and you can't always get the sub with dual 2 ohm coils either. You haven't made much of a point, yet. Neither have you
500 Watt CAFz'r
Joined: Aug 2001
Posts: 866
^LOL! [img]graemlins/thumb.gif[/img]
What the heck is the difference if your amp does 1000x1 @ 4 ohm mono, or 1000x1 at 1 ohm?
Same power.
Not many high end subs are SVC.
[img]graemlins/freak.gif[/img] dude you must go shopping
What the heck is the difference if your amp does 1000x1 @ 4 ohm mono, or 1000x1 at 1 ohm?
Same power.
Not many high end subs are SVC.
[img]graemlins/freak.gif[/img] dude you must go shopping
That's a great idea to have no SQ judges. If I use the most expensive Stinger wiring my car will sound the best. Or they could just add up total system cost, gear, not install, and whoever spends the most wins.
