Is there any good DC-coupled amps to buy?

[vintologi]

I have read that a lot of amplifiers will not actually reproduce direct current but i havn't been able to find good information regarding this.

With most reviews i see a small dropoff at 10hz, is that due to the amplifier itself not reproducing DC or is it due to limitations when it comes to the measurements?

 

[staticV3]

With most reviews i see a small dropoff at 10hz, is that due to the amplifier itself not reproducing DC or is it due to limitations when it comes to the measurements?

It's the former. Amir's measurement equipment can measure flat down to <1Hz.

 

[vintologi]

It's the former. Amir's measurement equipment can measure flat down to <1Hz.

Yep the benchmark AHB2 doesn't have that issue at 10hz

 

[staticV3]

Yep the benchmark AHB2 doesn't have that issue at 10hz

Not sure why this is presented as an issue. Your audio chain should filter out DC.
DC has no place in audio.

 

[fpitas]

Not sure why this is presented as an issue. Your audio chain should filter out DC.
DC has no place in audio.

Maybe it's the latest in sub sub sub sub sub bass?

 

[Plcamp]

Maybe it's the latest in sub sub sub sub sub bass?

The wavelength of sound at frequency pi (3.1415926 hz) is 109.18 m.

I’d expect something magical must be there and a lack of dc coupling is deliberately hiding it from us all.

 

[notsodeadlizard]

I, too, am outraged why the authorities tacitly forbid applying 30 or more volts DC to a speaker coil with 4 ohms DC resistance.
This is such an industry conspiracy.

 

[vintologi]

Not sure why this is presented as an issue.

It is a problem if the goal is to faithfully reproduce audio as it was recorded and mastered.

Your audio chain should filter out DC.
DC has no place in audio.

That's very much not the case.

I at the very least will need DC for testing purposes.

You can actually reproduce 0.1hz easier than people think (at least partly) you simply need a sealed room with sealed subwoofer element. Unfortunately without also having fans the reproduction will only be partial.

Whether or not you can actually percieve it is a different question, i might test that myself at some point.

I, too, am outraged why the authorities tacitly forbid applying 30 or more volts DC to a speaker coil with 4 ohms DC resistance.
This is such an industry conspiracy.

It's fairly easy to build speaker that can handle DC just fine, you just need to have a crossover filter and sufficient subwoofer elements.

Getting good performance in the midrange is much harder.

 

[fpitas]

It is a problem if the goal is to faithfully reproduce audio as it was recorded and mastered.

The equipment used to record music does not go down to DC. Nor do any of the common mediums have that capability.

 

[RayDunzl]

you simply need a sealed room

Yeah, I gotta get one of those.

Maybe use the fuselage of a small business jet.

What about wall flex?

I think my little big amps are DC coupled "to faithfully reproduce audio as it was recorded and mastered", but shut down if DC is detected.

 

[staticV3]

It is a problem if the goal is to faithfully reproduce audio as it was recorded and mastered.

DC is not audio. You can (and should) filter it out and it won't affect the audio in any way except positive.

 

[HarmonicTHD]

It is a problem if the goal is to faithfully reproduce audio as it was recorded and mastered.

That's very much not the case.

I at the very least will need DC for testing purposes.

You can actually reproduce 0.1hz easier than people think (at least partly) you simply need a sealed room with sealed subwoofer element. Unfortunately without also having fans the reproduction will only be partial.

Whether or not you can actually percieve it is a different question, i might test that myself at some point.

It's fairly easy to build speaker that can handle DC just fine, you just need to have a crossover filter and sufficient subwoofer elements.

Getting good performance in the midrange is much harder.

Can we see some music tracks which contain significant content of 10Hz or less?

 

[fpitas]

Can we see some music tracks which contain significant content of 10Hz or less?

I think some movie tracks have 5Hz or so, mainly from helicopters. Still not DC.

 

[HarmonicTHD]

I’d say, get one of those.

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But please don’t come and ask us about sound fidelity.

 

[HarmonicTHD]

I think some movie tracks have 5Hz or so, mainly from helicopters. Still not DC.

Yep and no music.

And for effects see the “Buttkicker” above

 

[fpitas]

The rotary subs are kind of cool, too. A breath of fresh air, you might say

 

[staticV3]

we see some music tracks which contain significant content of 10Hz or less?

https://www.audiosciencereview.com/...2-review-dac-headphone-amp.35882/post-1558493

https://www.audiosciencereview.com/...500-mkii-review-dac-hp-amp.29468/post-1402058

https://www.audiosciencereview.com/...o-review-dac-headphone-amp.27148/post-1263877

https://www.audiosciencereview.com/forum/index.php?threads/bass.18999/post-622474

 

[John_Siau]

Yep the benchmark AHB2 doesn't have that issue at 10hz

The AHB2 has a 0.1 Hz high pass filter. This keeps the phase response accurate at 10 to 20 Hz. In contrast, amplifiers that roll off near 10 Hz add delay to the low bass.

The 0.1 Hz high pass filter keeps DC out of your speakers (very important) without adding a delay to the low bass.

All Benchmark products measure -3 dB at 0.1 Hz.

 

[fpitas]

The AHB2 has a 0.1 Hz high pass filter. This keeps the phase response accurate at 10 to 20 Hz. In contrast, amplifiers that roll off near 10 Hz add delay to the low bass.

The 0.1 Hz high pass filter keeps DC out of your speakers (very important) without adding a delay to the low bass.

All Benchmark products measure -3 dB at 0.1 Hz.

Thanks John.

 

[Bob from Florida]

You can’t hear DC fed to a loudspeaker unless you increase the DC until ”snap, crackle, and pop” occurs which causes a “noxious odor” to fill your listening room.