[medium jim]

Maybe the question should be, What is the best type of amplification for subwoofers?

My subs are being driven by Class A/B SS amplification and I have no complaints. The bass it tight, fast and integrates well with planars.

I've heard that class D is excellent for subs and would like to hear from those who have first hand experience.  Better yet, those who have experience with Class D and other types of amplification for subs.

Jim

[roscoeiii]

I use two hampsters with treadmills. Though sometimes they run out of power if I forget to refill their food and water. YMMV.

[medium jim]

I use two hampsters with treadmills. Though sometimes they run out of power if I forget to refill their food and water. YMMV.

But do they integrate with your speakers?


Jim

[roscoeiii]

Of course. Integration is everything.  I made sure that their fur matched the cherry stain on my speaker cabinets.

[medium jim]

Again, I'm hoping to get some responses that will help those who are looking to buy a subwoofer(s) and the more information they have, the better.

Jim

[roscoeiii]

Well, if folks aren't interested in going the hamster route, then I do think that the high damping factors of many Class D amps could be a good thing for subwoofer bass (with the right driver of course). That high damping factor could give a good deal of control over that woofer, and it is tough to imagine a sub driver that would be designed with a low damping factor amp design in mind.

[medium jim]

I would think that the dampening factor would be a mute point as SS and Class D both have sufficient Dampening Factors, or do they?

Jim

[roscoeiii]

I would think that the dampening factor would be a mute point as SS and Class D both have sufficient Dampening Factors, or do they?

Jim

IIRC, class D amps often have higher damping factors than other SS amps. But with damping factor, you do encounter a point of diminishing returns. Perhaps the high damping factors of class D would be only noticeable for hard to control drivers.

[andy_c]

There's a good thread in the Lab about using pro amps for bass.  I bought two Crown XLS1500 amps, but my subs aren't built yet, so I haven't put the amps to use yet.

Speaking for myself, I'd avoid plate amps for DIY subs or commercial subs using plate amps.  The amps will be subject to significant vibration, and the effect on reliability is a question.  In the case of DIY subs, plate amps come and go, so if the amp fails a few years down the road, there's no guarantee you'll be able to find a replacement that fits.

[medium jim]

The problem with pro amps is the fan noise.  A well designed sub cabinet can virtually eliminate most if not all vibrations.  However, reliability is a valid point.  Which is the more reliable type of plate amp?  Which sounds better?

Jim

[andy_c]

The problem with pro amps is the fan noise.

That was discussed in the linked thread.  See, for example, this link from that thread.

A well designed sub cabinet can virtually eliminate most if not all vibrations.

With a plate amp, the heat sink is outside the box in free air, and the circuitry is generally exposed to the pressure waves inside the box. Said waves can only be eliminated by not using the sub.

However, reliability is a valid point.  Which is the more reliable type of plate amp?  Which sounds better?

The only plate amps I know about with consistently good recommendations from users are from a company called O Audio. They recently closed up shop though.  Various Parts Express plate amps are known for reliability problems.  So I don't know of any, and even if I did, I wouldn't recommend using them, for reasons I've already mentioned.

[medium jim]

No disrespect to Andy, but I don't share the same opinion regarding the reliability of Plate Amps and it is not the subject of the question at hand.  Andy, am I correct that your Crowns are Class D?  Maybe you could talk about them and if you have experience with SS class A/B or class B for bass.

Jim

[mcgsxr]

I have used a lot of different amp solutions for my various DIY sub builds.

I have had one plate amp fail, but it was 10 years old when it did.

I currently use 2 different plate amps, but both are remote from the sub box. 

He is a BASH 300w unit, the other a PE 500w A/B design.

If the PE amp dies, I will go pro for sure, as I have a dedicated media closet, so fan noise in the listening room will not be an issue.

[ctviggen]

I've had a parts express plate amp running for a few years now.  It's outside the sub, though. 

I've had a "pro" amp also, but the fan noise for me was horrendous even with replacing the fan to a quiet one.  I abhor fan noise.  My current HT computer is fanless. 

[Guy 13]

Hi all Audio Circle members.
I have/use two (02) Rythmik A370PEQ for my V1,
I have four (04) GR Research SA-1 for my two (02) V2
and I have two (02) Rythmik A370PEQ on my FG-12 Rythmik
sealed servo sub-woofer.

Guy 13

[TJHUB]

I have a pair of Behringer EP4000 amps driving a pair of 18" subs.  The amps are in my basement below my first floor audio system so fan noise isn't an issue for me.  However, I'd prefer good plate amps, but getting one with the power I need is limited and pricey.  Pro audio amps are a steal, so I'll make due with what I have.  I also have my Behringer EQ stacked on the amps.  It makes for a nice clean setup, especially the stuff that's out of sight. 

[AJinFLA]

The only plate amps I know about with consistently good recommendations from users are from a company called O Audio. They recently closed up shop though.  Various Parts Express plate amps are known for reliability problems.  So I don't know of any, and even if I did, I wouldn't recommend using them, for reasons I've already mentioned.

Hi Andy,

Having used all varieties for 20+ yrs, I'd say they (plate) are really no more/less reliable than their rack mount counterparts, IMO. Yes, it's true that some are known for poor or spotty reliability, but I have several that are 10+ years old, without back covers (which some do have) still going strong. Really more of a manufacturer than a format thing.

cheers,

AJ

[DS-21]

I've heard that class D is excellent for subs and would like to hear from those who have first hand experience.  Better yet, those who have experience with Class D and other types of amplification for subs.

D works best for very small sealed subs, because they can swing more voltage than AB while drawing the same current from the wall. But for most subs, a good AB or G amp will be fine.

FWIW, for my multisub system I use an ElectroVoice CPS-8.5. It's expensive, but to my knowledge it's the only amp available with that many channels (I run 5 subs) and a 12V trigger in just 2RU. (Also, it's made in Germany, which explains some of the cost. EV is owned by Bosch.) If I was willing to tolerate 8RU worth of sub amps, I would probably use three Dayton SA1000s and two NHT A1's.

For nearfield, single-sub use I like the Class G Dayton SA1000 (also rebadged variants, such as the Snell SPA-750) or the Class D Paradigm X-850. The Paradigm is more expensive but nice if (like me) you're lazy, because it includes the subwoofer variant of Anthem Room Correction, called "PBK" here. Even though the spring-loaded speaker terminals are annoying. Still, for equalizing a nearfield sub, ARC is quicker than pulling out the measurement gear and fiddling with a miniDSP, and gets about as good results.

FWIW, here's a survey of sub amps I wrote a couple months ago.

PS: Amps I currently own that are suitable for or designed for subwoofer use (may be incomplete)
EV CPS-8.5
Crest ProLite 2.0 (better-looking Peavey IPR pro amp variant)
NHT Pro B-20
pair of NHT A1
O-Audio BASH 500 plate amp
OEM variant of Dayton HPSA-1000 plate (from parted-out M-Design Eleganza Godfather)
pair of OEM 2-piece variant of Dayton HPSA500 (from two parted-out M-Design Eleganza Bellas)
Dayton HPSA-1000R
Snell SPA-750 (Dayton SA1000 rebadge)
Paradigm X-850

The EV CPS 8.5 and Paradigm X-850 are long-term keepers. Probably the Snell SPA 750 too, though don't have a current use for it. I'm saving the ProLite 2.0 and NHT B-20 for a family member's in-design-stage basement theater. The rest are not currently in use. Some of those (the NHT A1's and Oaudio BASH 500) have already been listed for sale in various places (including, I believe, here). Others will as I find the time/inclination to do it.