Suggestions for a Subwoofer Amp?

[Barry]

Hi folks. Looking for hi-current, stereo subwoofer amp recommendations. Something with great bass and control to drive a pair of Kinergetic Subwoofer SW-800 towers (5 x 10" drivers per side). What's significant is the speaker's nominal impedence of 3.2 ohms. I believe these have roughly ~ 90 dB efficiency but I'm still thinking I'd like 200-300 watts or so even though it might be overkill. System is tri-amped (heavily modified Magnepan 3.6s with Pass Labs XVR-1-3) and the subs are crossed over at 50Hz. Subs response is flat to about 15 Hz.

Could be a new or used piece but prefer not more than 5 years old or so for reliability. This system is primarily tube & tube hybrid-based (ARC Ref 40 Anniv, heavily modified and upgraded Counterpoint NP-220 amps on the 3.6s). Solid state is fine but class D types not my preference. Price range new or used roughly $5K although I could spend more.

Thanks so much for your help.

 

[DonH50]

Class D might be a decent choice for sub amps. You'll get more power for less heat and their lower damping factor (higher output impedance) at higher frequencies is not an issue for sub amps. I would definitely go SS for the sub amps. I would also consider a pair of monoblocks, allowing you to keep the speaker cables very short.

90 dB efficiency for a sub strikes me as pretty good. It does take more power at LF so a couple hundred watts is probably not a huge overkill. If you want to hit 110 dB peaks you could easily need 200 W.

Would you consider a pro amp like Crown or even Behringer? That would probably be the value leader. Then in increasing price Emotiva, Outlaw, Wyrd, Bryston, Krell, etc. There are also "kit" amps that would probably work OK from Parts Express, miniDSP, Marchand Electronics, etc.

 

[amirm]

I would also vote for a class D amp like Crown. I have tested them against very high end linear amps and when it comes to subwoofer or bass duty, they are better in every regard as Don mentions.

 

[JackD201]

I would likewise go for a Crown or maybe a Crest

 

[microstrip]

(...) I would also consider a pair of monoblocks, allowing you to keep the speaker cables very short.

Don,

An interesting issue. How does the total damping factor (amplifiers + cables) affect the perceived and measured quality of bass of a subwoofer? Do you know of any article on this aspect? When we have a system with multiple subwoofers, placing the amplifier near the speaker can be a problem, mostly because of the power cables. And a run of AWG8 cables has less than 10 mohm per meter.

 

[DonH50]

My experience is decades hold so take with a grain (block) of salt.

High output impedance causes FR aberrations and excessive driver "ringing". Especially in a sub it is difficult to hear such things but they are easily measured using FR sweeps and impulse testing. IME when people talk of a "fast" sub they are actually referring to a well-damped rsponse that does not ring after the signal is removed; I think that muddies the sound more than any lack of bandwidth on the "attack" side of the waveform. Proper integration with the mains (phasing) means the attck should be handled just fine; a slow ringing decay can make (in the extreme case) a tight kick drum sound like a kettle drum.

One major consideration is my experience, being only slightly younger than its owner, is rooted in the days when few amplifiers had low output impedance, The advent of high-power amplifiers and more research and development in the 70's and 80's has resulted in designs that perform much better than way back then. Your typical consumer AVR today has better amps than some of the high-end models of decades back.

A good amp provides enough charge storage that IMO the speaker cables are more an issue than the power cables. However, I would not claim how audible the effect is -- far too many variables, the listener being the largest.

You have to admit not many folk run 8 AWG speaker cables; they won't even fit most consumer terminals.

 

[daytona600]

Sanders sound systems magtech stereo , made in usa with a lifetime warranty 500wpc@8ohms will drive Anything and sounds excellent
$5500 roger sanders does f30days home trial , my pair did not go back
Will also drive your maggies no problem as well

 

[Wayne A. Pflughaupt]

Might also consider Carvin. I’ve been using a 1540 for a number of years now for my subs – no issues. Looks nicer in a home rack then most of the “bling” amps you see these days.

Regards,
Wayne A. Pflughaupt

 

[Barry]

Thanks folks many things to think about. It's not that important to me and I'm not looking for bling, but many of these pro audio class D amps are just ugly!

 

[JackD201]

How about older Bryston amps? Get a 2003 model and you'd still have 10 years warranty left.

 

[LL21]

How about older Bryston amps? Get a 2003 model and you'd still have 10 years warranty left.

Very good call.

 

[MCLSOUND]

I have a factory recapped Krell FPB 600 that would rock your world and not one person here will tell you any different.Krell is the ""BEST"" amplifier for bass control.This unit at 3ohms will put out a solid 2400 watts per side at 1%THD.Being that is fully rebuilt(july 2011) from Krell it will not need attention untill 2028...If you may be interested PM me and we can go from there.
thanks John

 

[Barry]

John Thanks. I have looked at Krell of course. Given the efficiency of the subs that's about 2K watts/channel more than I need! While I did not mention weight as a criteria, whatever I buy I also have to be able to lift it and I have yet to pursuade my wife to "lift weights" with me.