REVIEW: Surprised by SQ of Class-D Full Range amps!! Alpine PDX, JL Audio, Etc

[gunz4me2 10+ year member]

Full range class d has come a long way. It's only those who can't let go of the past that think otherwise. After all, with the hostile environment that the car truly is for the reproduction of audio, does one honestly think they can tell a difference between amplifier class topologies while actually driving? Really?

Then again, if you believe in hanging on to the past, taking up loads of space, and running inefficient current hogs because you feel that 30 year old 12 volt technology is superior, by all means run it! Just don't try to bring me into your little delusional world where you think that it is "better" than ANYTHING made today.

 

[Shinju 10+ year member]

I have made the jump to Class D topology all around. So far I like it, my only complaint is that I feel that the Alpine PDX 600.1 seems a little weak on putting out the low end, now when I say low end I am not talking about CRUSHING TEH LLOWZZZZ LOLZ I am a SQ guy I want the sub sonic for the effect and image. I had the SS filter set at 15hz and then I just turned it it off it felt like it made no difference at all felt like the bass was well empty.

But I will agree that old school stuff is fun and neat to collect and some of it is still viable to use in some instances, but the gear is old and the parts will give out and the technologies on amplifiers have gotten better.

This is coming from a guy who had more old school stuff then most of the people here, I sold it all and have nothing left of my collection. I run newer gear and I couldnt be more happy with the footprint vs output!

 

[cleansoundzz 10+ year member]

I have made the jump to Class D topology all around. So far I like it, my only complaint is that I feel that the Alpine PDX 600.1 seems a little weak on putting out the low end, now when I say low end I am not talking about CRUSHING TEH LLOWZZZZ LOLZ I am a SQ guy I want the sub sonic for the effect and image. I had the SS filter set at 15hz and then I just turned it it off it felt like it made no difference at all felt like the bass was well empty.
But I will agree that old school stuff is fun and neat to collect and some of it is still viable to use in some instances, but the gear is old and the parts will give out and the technologies on amplifiers have gotten better.

This is coming from a guy who had more old school stuff then most of the people here, I sold it all and have nothing left of my collection. I run newer gear and I couldnt be more happy with the footprint vs output!

I couldn't agree more with these statements. This is why I switched over to the Alpine PDX M-12 and F-4. Between using the M-12 and F-4 and Arc Audio KS 1000.1 & KS 300.4 the sound is exactly the same. The M12 at 1200 + watts is more efficient than the Arc Audio KS 1000.1 1000+ watts. The KS 300.4 and F-4 are neck and neck.

 

[cleansoundzz 10+ year member]

I have made the jump to Class D topology all around. So far I like it, my only complaint is that I feel that the Alpine PDX 600.1 seems a little weak on putting out the low end, now when I say low end I am not talking about CRUSHING TEH LLOWZZZZ LOLZ I am a SQ guy I want the sub sonic for the effect and image. I had the SS filter set at 15hz and then I just turned it it off it felt like it made no difference at all felt like the bass was well empty.
But I will agree that old school stuff is fun and neat to collect and some of it is still viable to use in some instances, but the gear is old and the parts will give out and the technologies on amplifiers have gotten better.

This is coming from a guy who had more old school stuff then most of the people here, I sold it all and have nothing left of my collection. I run newer gear and I couldnt be more happy with the footprint vs output!

I couldn't agree more with these statements. This is why I switched over to the Alpine PDX M-12 and F-4. Between using the M-12 and F-4 and Arc Audio KS 1000.1 & KS 300.4 the sound is exactly the same. The M12 at 1200 + watts is more efficient than the Arc Audio KS 1000.1 1000+ watts. The KS 300.4 and F-4 are neck and neck.

 

[PPI_GUY 10+ year member]

I have made the jump to Class D topology all around. So far I like it, my only complaint is that I feel that the Alpine PDX 600.1 seems a little weak on putting out the low end, now when I say low end I am not talking about CRUSHING TEH LLOWZZZZ LOLZ I am a SQ guy I want the sub sonic for the effect and image. I had the SS filter set at 15hz and then I just turned it it off it felt like it made no difference at all felt like the bass was well empty.
But I will agree that old school stuff is fun and neat to collect and some of it is still viable to use in some instances, but the gear is old and the parts will give out and the technologies on amplifiers have gotten better.

This is coming from a guy who had more old school stuff then most of the people here, I sold it all and have nothing left of my collection. I run newer gear and I couldnt be more happy with the footprint vs output!

Have you tried any other class D stuff? Specifically JL Audio XD/HD. Wondering how it compares with Alpine PDX?

I'm with you on the old school stuff. I seriously doubt I will be buying much more (if any) when the newer stuff is so much more efficent and with such a smaller footprint.

 

[Bettr n' Revrse 5,000+ posts]

Mehhhh I guess the new alpine stuff is getting better but I won't run anything new except maybe the type r 8

 

[rc10mike 10+ year member]

After a ton of said "trial and error" , Ive ended up using high end A/B amps in my setup. IMO, class D is still inferior.

Let me say that Im not concerned about SPL what so ever.

 

[PPI_GUY 10+ year member]

After a ton of said "trial and error" , Ive ended up using high end A/B amps in my setup. IMO, class D is still inferior.
Let me say that Im not concerned about SPL what so ever.

What were the issues you found with class D? Was it a SQ issue or something else?

 

[chillin 10+ year member]

I wish a full range class D 4ch would come brigeable to 1 ohm, or a 5ch that puts out close to 1000 to the sub. Something like a memphis belle or the Alphasonik PMA640HCA which can be run 160x2 +960X1.

Even the xdi listed above would suit my needs better if it could be ran @ 1 instead of 2 and put out a few hundred more. maybe a 100x2 and 750 to the sub @1 ohm

 

[rc10mike 10+ year member]

Honestly, it wasnt the SQ, it was the fact that no matter what I did, my full-range class D amp on my front stage would pick up any noise in the system. Including picking up noise from other class d amps in my system. Switching noises from my (tried many) sub amp were being picked up and played through my front speakers. I have a huge thread on it on DIYMA, including a thread where I offered money to someone who could help me out. I loved my JL HD600/4, but after a year, and having JL themselves come out to see my issue, I just got rid of it and my problems went away, and yes, JL let me try another brand new 600/4.

Thats my experience with full range class D from a leading company.

 

[PPI_GUY 10+ year member]

Honestly, it wasnt the SQ, it was the fact that no matter what I did, my full-range class D amp on my front stage would pick up any noise in the system. Including picking up noise from other class d amps in my system. Switching noises from my (tried many) sub amp were being picked up and played through my front speakers. I have a huge thread on it on DIYMA, including a thread where I offered money to someone who could help me out. I loved my JL HD600/4, but after a year, and having JL themselves come out to see my issue, I just got rid of it and my problems went away, and yes, JL let me try another brand new 600/4.
Thats my experience with full range class D from a leading company.

Wow. That's crazy! Did the JL people have any idea what the cause was? Was it a problem they had heard about from other customers before you? If it was/is, that should have triggered a recall I would think.

I can't imagine how the mid/high amp was picking up the switching frequency (or some harmonic) and adding it to the signal.

 

[gunz4me2 10+ year member]

Class D amplifiers are notorious for causing RFI/EMI issues, but that never mattered to me because I don't listen to the radio. Unfortunately, EMI can be a huge issue amp to amp and nearly impossible to solve. For example, I witnessed a setup where one class d amplifier was under the seat and the other was in the trunk. The class d amplifier under the seat made noise while the class d sub amp in the trunk was just powered up. Power off the trunk amp, no more noise. Replace the amp under the seat with a class ab amplifier, no more noise. I wonder if that is what rc10mike's problem was?

 

[rc10mike 10+ year member]

Class D amplifiers are notorious for causing RFI/EMI issues, but that never mattered to me because I don't listen to the radio. Unfortunately, EMI can be a huge issue amp to amp and nearly impossible to solve. For example, I witnessed a setup where one class d amplifier was under the seat and the other was in the trunk. The class d amplifier under the seat made noise while the class d sub amp in the trunk was just powered up. Power off the trunk amp, no more noise. Replace the amp under the seat with a class ab amplifier, no more noise. I wonder if that is what rc10mike's problem was?

Almost exactly my problem, except they were both in the trunk. The HD600/4 simply did not like another class d amp in the chain.

 

[rc10mike 10+ year member]

Wow. That's crazy! Did the JL people have any idea what the cause was? Was it a problem they had heard about from other customers before you? If it was/is, that should have triggered a recall I would think. I can't imagine how the mid/high amp was picking up the switching frequency (or some harmonic) and adding it to the signal.

They didnt know either, and they didnt really say if it was a problem with other peoples amps..

 

[chillin 10+ year member]

That's all the more reason a more powerful 3 or 5 channel would be nice, so 2 different class d amps are not necessary to get the sub output some of us want.