Class D car amps for home use?

[JRS]

Maybe I have been looking in all the wrong places but I can't seem to find a 100+ Watts/side stereo amp. Ultimately, I hope to get a 6 channel beast from Buckeye, but for now I just need 75-125W to drive some studio monitor 2 ways I'm building. Several class AB amps in that range from the big Japanese firms and a few from Emotiva,

So looking over the car stereo offerings there are nearly a dozen bridgeable 4 channel amps in the 50W/channel, that would allow me to biamp if I wanted to, or bridge each pair to get 150-200/side (at 13.2 V) for around $300 new. Add a 500W computer power supply for another 75 and I'm looking at a seriously capable amp for well under 250 if I go used.

So apart from aesthetics (if it works out I might look for a dressier computer case than the CPU) and potential fan noise (that can be remedied by buying a quiet fan)from the PS , where's the fly in the ointment. Most of these have THD stats in the
< 0.1 while S/N run from 85 to 105. Certainly not SOTA, but likely good enough. And yes I could look for a 5 channel discrete Denon or Yamaha of the right vintage off of e bay for a song, but doubt any will be nearly this capable.

Thoughts: spinning my wheels or am I on a path to some cost effective and excellent amplification. Some of the product would be so useful in the home arena--DSP amps with PEQ, LP and HP XO filters multich/bridgeable that aren't pro sound are on that list. streaming-->DAC-->amp and done!

 

[DonH56]

You'd have to buy a high-power 12 V supply and wire it up; you might need to modify a standard computer supply for lower noise. But many folk have done that and are happy with the results.

As for two-channel amps, Buckeye does have one that meets your requirements, albeit more expensive than your used solution. One possibility is to buy a two-channel amp now and multichannel version (four or whatever) later when you needed. Probably cheaper/better in the long run than something now, something later...

Two-channel NC252MP $579 shipped: https://www.audiosciencereview.com/...amplifier-builder-line-up-announcement.16835/

6-channel review using the NC252MP modules:

Buckeye 6 Channel Amplifier Review

This is a review and detailed measurements of the Buckeye Hypex NC252MP based, 6-channel amplifier. It costs US $1149 as of this writing. The owner/builder is @Buckeye Amps on our forum. The looks are fine for a well-priced build: The unit is quite light courtesy of rather thin sheet...

www.audiosciencereview.com

Going used I'd probably just look for a standard home amplifier or repurpose an old AVR.

 

[JRS]

You'd have to buy a high-power 12 V supply and wire it up; you might need to modify a standard computer supply for lower noise. But many folk have done that and are happy with the results.

As for two-channel amps, Buckeye does have one that meets your requirements, albeit more expensive than your used solution. One possibility is to buy a two-channel amp now and multichannel version (four or whatever) later when you needed. Probably cheaper/better in the long run than something now, something later...

Two-channel NC252MP $579 shipped: https://www.audiosciencereview.com/...amplifier-builder-line-up-announcement.16835/

6-channel review using the NC252MP modules:

Buckeye 6 Channel Amplifier Review

This is a review and detailed measurements of the Buckeye Hypex NC252MP based, 6-channel amplifier. It costs US $1149 as of this writing. The owner/builder is @Buckeye Amps on our forum. The looks are fine for a well-priced build: The unit is quite light courtesy of rather thin sheet...

www.audiosciencereview.com

Going used I'd probably just look for a standard home amplifier or repurpose an old AVR.

In terms of simplicity, you are right no doubt about looking for some used stuff. Hadn't considered buying the 2 CH now and sending the same piece for the other channels. And I guess part of me just wants to do it for the sake of doing it. Besides there is some really good looking car audio stuff--maybe much is over the top boy racer stuff style, but some stylish gear. Anyway just collecting some opinions and ideas for now while I anticipate starting the speaker build in a few weeks. Hoping to put together a killer 2ch system for under 3200.

 

[MaxwellsEq]

Are the power capabilities quoted like-for-like? I've seen inconsistences between mains-powered audio power amplifiers and car battery equivalents. Are these "peak" or "burst" power values or e.g. sustained power (i.e. able to operate for longer than an hour after an hour's pre-conditioning) at 1% distortion and 10% distortion.

 

[JRS]

Are the power capabilities quoted like-for-like? I've seen inconsistences between mains-powered audio power amplifiers and car battery equivalents. Are these "peak" or "burst" power values or e.g. sustained power (i.e. able to operate for longer than an hour after an hour's pre-conditioning) at 1% distortion and 10% distortion.

I'm very careful about power specs these days, and rue the day when we abandoned all of the previous IEC standards for the current nonsense where 6kw amps are on sale at amazon for $69.95.

So yea, looks like almost all of these specs are RMS at 1% which may as well be 0.1 % given the dynamic limitations of the topology. As to preconditioning I doubt it given how incredibly competitive the market is. But as a rule the smps are heatsinked and lots of open space--likely a function of the heritage of running amp sucking Class AB monsters in very inhospitable environments like the trunk or behind the dash. It surprises me that class D is still sort of the new kid in class; given the advantages I'd think it would be SOP by now.

 

[MaxwellsEq]

Fascinating! Has anyone done a bench test shootout between competing automotive and domestic kit? I'm not into car audio, so I don't know where authoritative measurements are published.

 

[JRS]

Fascinating! Has anyone done a bench test shootout between competing automotive and domestic kit? I'm not into car audio, so I don't know where authoritative measurements are published.

There are some worthwhile msmts that include specs that are nearly as good as home kit, the one exception being the noise floor with S/N ratios in the eighties which is way worse than SOTA home gear.
But its likely in the neighborhood of most AVR's using AB topo. Given that the noise floor of an automobile is what it is, suspect irrelevance, and only audible in a home setup with horns.

I still see it as an interesting exercise in putting a test rig together as I'm shooting almost the entire expense on the speakers--1750 for drivers and xo and 400 for the cabinets. Leaves me about a grand for electronics and needing to save money--want some power for a bridge til I can do the electronics properly and proof of concept.for a many channeled home theater setup. Plus as I said there is some product for which no single chassis counterpart exists.

 

[MaxwellsEq]

That's interesting! Personally as an engineer, I consider reducing sources of noise to be more important than minimising distortion. As you say, for a car noise may not be so important.

 

[JRS]

That's interesting! Personally as an engineer, I consider reducing sources of noise to be more important than minimising distortion. As you say, for a car noise may not be so important.

Agreed. But controlling noise might be more costly in an environment that's noisy electrically and acoustically. The 1% spec I see more and more as if it's become an informal standard, Amir uses it so it can't be too much of a compromise for audible distortion, even though he likes much, much less. What was new to me coming here was the practice of lumping noise and distortion into SINAD spec.

 

[Prana Ferox]

Why rule out used pro sound amps?

 

[JRS]

Why rule out used pro sound amps?

Haven't entirely. Checking used market see mostly Crown and Q something which have fsns and are gaudy visually. I understand 10 or 15 dill get one a quiet fan which would suffice in a home setup.

 

[Prana Ferox]

I can't promise this is true of every make and model but generally PA amp fans don't come on unless you're really hammering on them or running them in hot outdoor ambient conditions. I have two Crowns and I've never heard the fans kick on. I agree you wouldn't want to make them the centerpiece of your interior decor (although a classic Yamaha is quite fetching IMO) but there are ways around that. Also some amps will have crossovers and / or DSP of varying sophistication.

 

[JRS]

I can't promise this is true of every make and model but generally PA amp fans don't come on unless you're really hammering on them or running them in hot outdoor ambient conditions. I have two Crowns and I've never heard the fans kick on. I agree you wouldn't want to make them the centerpiece of your interior decor (although a classic Yamaha is quite fetching IMO) but there are ways around that. Also some amps will have crossovers and / or DSP of varying sophistication.

I see so many lines within the Crown brand I get confused about what is a good price, is there something I should be looking for? And also are there other brands that can be trusted--Behringer or QSC I see sold at Sweetwater. Behringer seems to be a hit/miss proposition with their other products, but I know nothing of QSC. And what should I expect to pay for something decent--like less than 10 years old and in decent condition?

 

[Prana Ferox]

Crown has a lot of different tiers but I wouldn't think you'd go wrong one. QSC is good. Behringer is.... ehhh... they can have a lot of features for a price point. There are plenty of good brands and most of them are branches of the same companies these days.

I would say, check eBay sold listings for price comparisons, and keep an eye out for odd niche products (like having Phoenix connectors on the back instead of regular speaker terminals or Speakon) that you probably don't want to deal with. And like anything, it is good to try to test it before buying.

 

[JRS]

Crown has a lot of different tiers but I wouldn't think you'd go wrong one. QSC is good. Behringer is.... ehhh... they can have a lot of features for a price point. There are plenty of good brands and most of them are branches of the same companies these days.

I would say, check eBay sold listings for price comparisons, and keep an eye out for odd niche products (like having Phoenix connectors on the back instead of regular speaker terminals or Speakon) that you probably don't want to deal with. And like anything, it is good to try to test it before buying.

Thanks. I have had nothing but good luck on ebay with used amps--bought a Marantz 180 x 5, and an Adcom 60 x 4 20 years ago which were all doing well until a string of user errors led to their demise. I had planned to gut them and put Class D modules in them, but like a few other projects this one was derailed by some crappy life events ending without access to all of my gear. Thats still in court. So starting from scratch essentially--I do have a laptop, a CDP and the Topping Dx 3+ pro which will serve as the preamp. And 2k put away for the loudspeaker build which I'll do a thread on here in about 6 weeks hopefully.