ISO DC-powered but SQ high current power amps w/bass-mgmnt

[john61ct]

In search of reco's for a 5.2 system, main pair being OG LS50, so likely adding a pair of mid-to-bass reinforcement boxen depending how high FR the subs go (not that relevant here )

Just as an example for comparison, I came across the 4-channel Polk Audio PA-D4000.

125W RMS x 4 at 4Ω, 200W @ 2Ω and 400W x 2 bridged (minimum 4Ω)

can switch input mode to stereo, so the front pair input is routed to both F&R outputs

includes adjustable crossovers - HPF LPF and bandpass! for front / rear pairs separately

My use case is off-grid and nomadic, not so much cars & vans or open boats, but definitely DC powered and very space constrained.

Looking for good SQ prioritized over blasting SPL but (esp. when outdoors) looking for AMAP of the latter with a minimum sacrifice of the former.

If necessary I "can" (reluctantly ) use AC-powered home gear via sine-wave inverters, but that adds expense & space required and wastes precious electrical capacity

Focusing here on Power amps specifically, with the above PA-D4000 watts being a minimum, apples to apples real RMS not just mfg claims.

I **really** like the idea of bridgeable for flexibility, going between four channels and two, or from two to monobloc when a speaker needs it.

I also highly value the built-in bass management, at least flexible crossovers, if not time domain / polarity. Bandpass especially...

One thing possibly missing from the Polks is line level outputs, their FR filtering only affects speaker outputs.

Note that otherwise I'm thinking the likes of Adcom GFA-555 for the KEF main pair, them needing big current and high damping / load independance,

so the main focus here can be for driving less demanding speakers (yet to be selected / built), for the center, rear pair, subs and (maybe) the bass reinforcement boxen.

But if you know of a DC-powered extra high-current power amp at reasonable pricing for just that pair (not all the xover features) please speak up!

TIA...

 

[john61ct]

Side note, apparently some Hypex nCore Ice type modules can be driven by High voltage DC bypasding the ACtoDC transformer. My standard solar "house banks" and genset are 48Vdc, and I can go to just about any DC voltage needed via DCDC converters if needed, would prefer that to AC inverters.

But very few people I've "met" online are qualified to advise on that path in any detail.

 

[kyuu]

I mean, any amp that uses an external power brick can be easily powered by an external battery bank by just bypassing the brick and connecting the barrel directly to the batteries (or DC-DC converter if the voltage of the battery bank doesn't match), as long as the batteries/converter can supply the requisite peak amperage draw.

 

[john61ct]

Yes, so can you suggest comparable good SQ home amps with external AC-DC bricks?

The built-in bass management seems much more rare, not to mention bridgeable

 

[voodooless]

You’ll get quite a lot of DC powered options if you look at the car audio market. Plenty if amps with bass management, some even have DSP.

As for consumer hifi, that is more difficult. Most amps with bass management will have a built-in PSU. Plenty of separate amps have 48V power bricks, though. Topping and Fosi have several, just check the reviews here. For bass management you would need a separate device.

 

[john61ct]

So do you know of 4-channel amps with those features but better SQ and/or more power Polk Audio PA-D4000 ?

Which forums similar to ASR deal with "car audio"?

 

[voodooless]

So do you know of 4-channel amps with those features but better SQ and/or more power Polk Audio PA-D4000 ?

What is wrong with the sound quality of the amp? Here are some objective measurements:

Polk Audio PA D4000.4 Amplifier

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www.pasmag.com

Amps don’t have a sound unless they are seriously broken. This one isn’t, the 60 SINAD isn’t stellar, but ultimately not critical. Power wise, this should be plenty for the LS50. I run them with less than half if this just fine.

 

[voodooless]

Here are a few reviews on ASR of car audio amps:

Search results for query: Car

www.audiosciencereview.com

Note that most of these aren’t very good performers. The option of a small home hifi class D amp with direct DC input would yield better potential. Get one of the WiiM devices for some DSP and bass management, and you should be set.

 

[kyuu]

There's the recently reviewed Aiyama A20. Takes 48V, which should be easy to provide with a bank of 12V (or a 48V li-ion), subwoofer out, decent amount of power, and inexpensive.

The entire Aiyama lineup seems to take 24-48V DC in, so you could look through the product lineup to see what would work best for you.

 

[kyuu]

Note that most of these aren’t very good performers. The option of a small home hifi class D amp with direct DC input would yield better potential. Get one of the WiiM devices for some DSP and bass management, and you should be set.

The problem is that the Wiims all have an internal PSU, so the OP wouldn't be able to run that off the batteries without opening it up and trying to bypass it (I wouldn't recommend that).

 

[voodooless]

The problem is that the Wiims all have an internal PSU, so the OP wouldn't be able to run that off the batteries without opening it up and trying to bypass it (I wouldn't recommend that).

Yes. I would consider having AC power around would always be a good idea anyway. But MiniDSP has a special car audio version of its DSP.

Another option would be to get one of those Wondom/Sure amplifier boards. Some come with DSP, and can run on 24/48V as well. I suspect they will be better than many car audio amps.

 

[john61ct]

To help narrow things down, focus the thread topic, I am looking here for Power Amps with built in bass management like the Polk model, bridgeable and starting with 4-channels if that exists.

I would like better SQ (less distortion and noise) than that model, if that exists.

The Polk's Watts power output level MIGHT be enough for Center and Rear, and bass reinforcement if needed.

However - could be a different amp - I am also looking to (safely) get maximum SPL out of OG LS50s, high damping factor and most importantly high Current amps output for load independence.

Also I believe to drive true subs will also require higher Watts power.

I believe the Wiim Ultra Amp might be a good option but off topic here since a large sw inverter would be required.

@voodooless
I do not believe Wondom/Sure amplifier boards put out enough power, maybe there are line-level bass management solutions there, but really hoping to avoid DIY.

The reason I want bass management built into the Power Amp is to avoid paying more for solutions like dedicated DSP boxen, in future I may be able to afford getting into that for EQ including room correction, but in my modular stepwise project plan I want simpler less expensive crossover functionality

similar to what that Polk model offers.

 

[voodooless]

Center and Rear

So how do you get multichannel audio? Seems like that might be part of the puzzle.

 

[john61ct]

There's the recently reviewed Aiyama A20. Takes 48V, which should be easy to provide with a bank of 12V (or a 48V li-ion), subwoofer out, decent amount of power, and inexpensive.

The entire Aiyama lineup seems to take 24-48V DC in, so you could look through the product lineup to see what would work best for you.

Thanks will check those out.

TPA3255 in stereo BTL maxes out at ~150 wpc into an 8-ohm load, but is it stable when the LS50s drop impedence at max SPL? I don't think stereo implementations can be further bridged to go higher as monobloc?

The 3e A7 looks a bit better than Fosi v3 Mono?

I'm looking for not only at least that level of power output - maybe at 60Vdc input? but also the built in bass management

I should be able to get by on the main pair (where I need that power) with HPF only

but really the LPF / HPF / BPF flexibility the Polk unit offers is really what I'm after built into the amp.

 

[john61ct]

So how do you get multichannel audio? Seems like that might be part of the puzzle.

Schiit SYN as pre processor.

 

[john61ct]

Here are a few reviews on ASR of car audio amps

Is there a forum outside of ASR frequented by audiophiles that are focused on mobile DC use cases? Yes "car audio" may have to be enough, but SQ not the boomy SPL guys. Maybe for RVs, or yachts?

I like JL Audio as a brand but pricey to get up to high true-RMS levels.

 

[john61ct]

having AC power around would always be a good idea

Of course inverters are fine when necessary

Sources and pre-amps are low power usage, does not cost much in quality inverters nor waste much Ah/day capacity.

The Power Amp category is a different beast.

 

[voodooless]

The Power Amp category is a different beast.

Sort of. They need peak power for sure, but the average power draw is generally not very high with efficient class D amps. Even AB amps aren’t too bad.

I can run my house of a 6kW inverter as part of a PV/battery system. These things are really cost efficient nowadays.

Basically you want an AVR without buying and AVR. Probably getting an AVR might still be the most sensible option.

 

[john61ct]

Weird telling me what I want. I have **absolutely zero** desire for any AVR, even one worth thousands offered to me for free. This is not for a house, and how I want to design my electric systems is very much off topic.

To all, please respond to my actual questions, not try to tell me about other directions I "should" be taking.

 

[john61ct]

AIYIMA A20

Only partly through the thread and, although HPF is rightly touted as rare in home amps,

the power output seems much **lower** than the PA-D4000 Wpc even in 4- channel mode,

never mind its giving the option for 400W x 2 bridged.

Note my preferred power amp if on grid AC would be GFA-555, not that all that output power is strictly required, but I do want headroom, not to fall short.

And they botched the PFFB which if I were to go for TPA3255 I think LS50s at high SPL mid-bass really do need.

The other more sensitive speakers might be OK at A20's lower power but they need LPF / BPF not just HPF...

It does look like great value for nearfield / desktop use case though, thanks for the pointer