Disregarding power output and low impedance handling, which type of amp will drive a subwoofer better in respect of sound quality, especially for tight punchy bass? Would I be correct in assuming a good quality 2 channel amp will often have a higher damping factor and lower S/N ratio to a class-D? (I'm only really referring to high quality amps here.)

All oppinions welcome...
cheers

as i understand it class-d is a lower resolution amplifier topology, that is designed primarily for efficiency (ie, high power output). home audiophile tend to steer away from class-d. so i guess theoretically a good class-a/b 2-channel amp would provide greater resolution and hence a more accurate low end.

what actually happens in the audible world could be another thing i've never heard the differences myself.

but yeah, class-d was invented for power, not for SQ, whereas a/b was designed to be a cost effective and low-current topology for general sound quality purposes.

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Custom SQ System

Source: Clarion DRX-9675z - Front Stage: Boston Acoustics Pro 6.5's - Centre Channel: Boston Acoustics FS50 Midrange - Ambient Satellites: Boston Acoustics 3/4" Kortec Tweeters - Processors: Audiocontrol EQT's - Subwoofers: Earthquake BR12's - Amplifiers: Kicker IX404's - Power: Stinger 1 Farad HPM Capacitor
Sounding sweet and taking it to the street

IMO a class D would be better - due to much better efficiency, thus less stress on your cars electrical system and less voltage drop



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- A proud member of Team Gates - A proud supporter of the CAA SPL project

presuming you have a sufficiently strong powersupply, and you're looking at premium amps, and you want SQ, then you could consider a class AB monobloc. just coz it's class AB doesn't mean you need a 2-channel to bridge for subs. what's more, the multichannel is likely designed with smaller speakers in mind so not have the internal power supply or high current design to go with gutsy mono performance.

not to say a premium 2-channel is not good. but i would expect a monobloc to be better, being designed with subs in mind.

there are some very good 2-channels, especially those that are actually built around a 'dual mono' design: hertz H320, dls dual mono, etc.

however, a couple nice class AB monoblocs include the audison's:
*LRx1.400 rated at 1x350/660/900WRMS into 4/2/1ohm respectively
*VRx1.500 (new series 2) rated at 1x560/1080/2000WRMS into 4/2/1ohm respectively

and most monoblocs include a nice steep 24dB/oct LP xover, and often a subsonic filter.

hope this helps.

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/////ALPINE audison DYNAUDIO »»»morel polkaudio OPTIMA Stinger LIGHTNINGAUDIO

Issues of harassment, conflict, vindictive allegations, or unfairness, personal or observed, should be reported to me via Private Messages or at [email="shiny_car@caraudioaustralia.com"]shiny_car@caraudioaustralia.com[/email]

I run a MTX 500d monoblock on an alpine type R sub and to be perfectly honest (i've run it off an a/b amp for a short bit) i couldn't tell even the slightest difference, i mean, the difference between amps at those freq's would be completely in audible... I mean, if you were looking at a cheap amp compared to an exxy mono block (class d) then you'd tell the difference... If going for a class a/b amp, then i'd highly recommend a good brand and a mono block... Monoblocks are generally designed for sub usage and also the power rating of some "midrange" to cheaper amps don't produce their rated power across the whole frequency range... However, a class d amp can (well, most) only produce from 200hz down.... Some of them are limited due to design conflicts... However, that said, i'd definately recommend a good class d over an a/b only because of power usage, but i would never use a full range class d amp on my splits... Just because they weren't really designed for that......
Aaron
P.S. if it doesn't make sense, sorry I'm tired

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Noise producer - Clarion DRX9675
Noise Increasers - MTX 500D - Pioneer GMX-944 - Bridged to the front stage
Making Noise Heard - CDT Audio HD Splits - Pioneer Coax (Bah!)
Low Bumpy Noises - Alpine Type R - Sealed 1 cuft(Going to be 2 if i need it)
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-Team SQ, A Reality Not a Dream :)
-Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you're a mile away and you have their shoes.

My personal experience going from 2 different A/B amps (Alpine V12 and Kicker ZR, both quality things) to the JL Audio 500/1 Class D is that control actually improved in my system, so with a quality product I wouldn't be too concerned about any potential SQ loss.

In car audio applications, the current crop of Class D's seems to get the job done very well.

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Mazda SP20 - NOT yellow,Dynamat Extreme and G Spot in front doors
HU - Alpine CDA-7876RB
Audison VRx 2.150EX front stage amp
JL Audio 500/1 Class D monoblock sub amp
Front Stage - Morel HCW 6.5 woofers, Morel MT2 tweeters, Morel MX2.2 x-overs.
Rear fill - stockies with power from HU (not that they get any)
Sub - Kicker S12L72 in 75 litre 30Hz slot-ported display box.
Stinger cables and connectors etc
TEAM AUDISON SQ WITH ATTITUDE

well there you have it as critter has highlighted, for him, class-d made an improvement. so while theoretically a class a/b has better resolution, in the real world, there are other factors at play.

that's one of the things i argue strongly in car audio - don't get fixated on specifications, tradition, brand, model - what really matters is sonic performance in the car, and the only way to judge that is to hook it up and listen. ive heard $150 speakers sound better than $1,300 speakers, there are just no hard and fast rules

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Custom SQ System

Source: Clarion DRX-9675z - Front Stage: Boston Acoustics Pro 6.5's - Centre Channel: Boston Acoustics FS50 Midrange - Ambient Satellites: Boston Acoustics 3/4" Kortec Tweeters - Processors: Audiocontrol EQT's - Subwoofers: Earthquake BR12's - Amplifiers: Kicker IX404's - Power: Stinger 1 Farad HPM Capacitor
Sounding sweet and taking it to the street

Thanks everyone, appreciate the comments.

I was just curious as to ppl's oppinions on this topic. My personal oppinion is that the power capabilities, low impedance handling and high efficiency of class-d amps outweighs any potential SQ problems when it comes to Subs.

Oh yeah, I'm a big fan of class a/b monoblocks too.

cheers

This is a perfect example, as T-Bro has alluded, of establishing what actually works in a system IMO.

Forget specs and the numbers game yada yada. I cetainly didn't expect the level of improvement that JL provides compared to the ZR it relaced, tho' I did think it should work well.
It had been a case of chasing efficiency to provide sufficient power for the hungry L7 and good damping for a ported enclosure.

I'm letting you inside my head now. Scary

And thereby tells the tale of the value of CAA.
There is gonna be someone here who has done it/ tried it/ found out if it gets the result, and we can all access that bank of experience and benefit ~ with no sales pitch attached !!

*Ends CAA Promo rant*


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Mazda SP20 - NOT yellow,Dynamat Extreme and G Spot in front doors
HU - Alpine CDA-7876RB
Audison VRx 2.150EX front stage amp
JL Audio 500/1 Class D monoblock sub amp
Front Stage - Morel HCW 6.5 woofers, Morel MT2 tweeters, Morel MX2.2 x-overs.
Rear fill - stockies with power from HU (not that they get any)
Sub - Kicker S12L72 in 75 litre 30Hz slot-ported display box.
Stinger cables and connectors etc
TEAM AUDISON SQ WITH ATTITUDE

quote:

---

Originally posted by Critter:
My personal experience going from 2 different A/B amps (Alpine V12 and Kicker ZR, both quality things) to the JL Audio 500/1 Class D is that control actually improved in my system, so with a quality product I wouldn't be too concerned about any potential SQ loss.

---

hee,hee, come on guys. this is not a fair conclusion to draw, that class D is better than class AB. although i realise this isn't exactly the message you're trying to convey.

it's the amp design at stake here. comparing a monobloc to a bridged 2-channel is no comparison. as i mentioned earlier, a good monobloc should romp it in ahead of a bridged 2-channel by virtue of the design.

so a class AB monobloc is as good if not better than a class D one in terms of SQ.

*ducks and weaves from hurls of abuse*

efficiency is another matter.

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/////ALPINE audison DYNAUDIO »»»morel polkaudio OPTIMA Stinger LIGHTNINGAUDIO

Issues of harassment, conflict, vindictive allegations, or unfairness, personal or observed, should be reported to me via Private Messages or at [email="shiny_car@caraudioaustralia.com"]shiny_car@caraudioaustralia.com[/email]

[Edited 1 time by shiny_car on 19 September 2002 at 14:54]

shiny is safe at 1000k's range


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Mazda SP20 - NOT yellow,Dynamat Extreme and G Spot in front doors
HU - Alpine CDA-7876RB
Audison VRx 2.150EX front stage amp
JL Audio 500/1 Class D monoblock sub amp
Front Stage - Morel HCW 6.5 woofers, Morel MT2 tweeters, Morel MX2.2 x-overs.
Rear fill - stockies with power from HU (not that they get any)
Sub - Kicker S12L72 in 75 litre 30Hz slot-ported display box.
Stinger cables and connectors etc
TEAM AUDISON SQ WITH ATTITUDE

D class amps are more efficent and draw less current but have more distortion. a Ab class amp will give you better sound.

/me yells from rooftop

"GO THE CLASS D"

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Team Tycoon - Dollars n dB's
a little Beyond Audio and a little Power = BUUURRRRP

There are Class D's and Class D's, just like there are Class A/B's and Class A/B's.

JL Audio 500/1 THD 0.05%......clean enough for me



------------------
Mazda SP20 - NOT yellow,Dynamat Extreme and G Spot in front doors
HU - Alpine CDA-7876RB
Audison VRx 2.150EX front stage amp
JL Audio 500/1 Class D monoblock sub amp
Front Stage - Morel HCW 6.5 woofers, Morel MT2 tweeters, Morel MX2.2 x-overs.
Rear fill - stockies with power from HU (not that they get any)
Sub - Kicker S12L72 in 75 litre 30Hz slot-ported display box.
Stinger cables and connectors etc
TEAM AUDISON SQ WITH ATTITUDE

So are you suggesting that i can then use my class d as a sq amp?
With a THD of 1% @ sub bass frequencies, would i not have to have bionic hearing to notice the diff btw mine and critters?

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Waiting to be installed
Rockford Fosgate RFX9300
Rockford Fosgate BD1000.1
Stinger HPM Series Wiring

quote:

---

Originally posted by Jetstream:
With a THD of 1% @ sub bass frequencies, would i not have to have bionic hearing to notice the diff btw mine and critters?

---

regarding THD alone, yes, more than a bionic ear.

an amp is the sum of its parts and the design, so THD is a poor representative of SQ and function. i think critter was having us on.

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/////ALPINE audison DYNAUDIO »»»morel polkaudio OPTIMA Stinger LIGHTNINGAUDIO

Issues of harassment, conflict, vindictive allegations, or unfairness, personal or observed, should be reported to me via Private Messages or at [email="shiny_car@caraudioaustralia.com"]shiny_car@caraudioaustralia.com[/email]

Caught red-handed!!
You're no fun shiny......

Umm, yeah, the point is there's amps and there's amps. Good ones are good ones and so on. The numbers really mean diddly-squat IMO.



------------------
Mazda SP20 - NOT yellow,Dynamat Extreme and G Spot in front doors
HU - Alpine CDA-7876RB
Audison VRx 2.150EX front stage amp
JL Audio 500/1 Class D monoblock sub amp
Front Stage - Morel HCW 6.5 woofers, Morel MT2 tweeters, Morel MX2.2 x-overs.
Rear fill - stockies with power from HU (not that they get any)
Sub - Kicker S12L72 in 75 litre 30Hz slot-ported display box.
Stinger cables and connectors etc
TEAM AUDISON SQ WITH ATTITUDE