Genuine Class D question

[treesey]

In my usual roundabout way of seeking audio nirvana, I've bought another AV Receiver to play various versions of old but recently remixed (or new) music in 5.1 audio, which is why this question is in the HiFi section.

It's a Class D AVR, and it does sound rather good, but it still gets somewhat warm when I rotate the dial towards 11.

So Class Ds still generate lost energy as heat, just not so much as A-B etc.

I was expecting no heat at all - this is excellent, as I can still reduce the electricity bill, AND listen to loud multichannel music, AND heat the house this winter.

Are there any 'HiFi' good Class D active subwoofers at reasonable prices please?

PS I'm bi-amping the Mission 753s from the AVR as main L and R, and they respond nicely to 220W per channel into 6ohms

 

[davidf]

Try NOT bi-amping the 753s from the AVR. It’s just over complicating things, and it’s all coming from the same power supply anyway - any major benefit from bi-amping will come from separate amplifiers with separate transformers. Despite using fairly budget drivers, the 753s are quite demanding, so this may be adding to the demand on the amplifier.

What is the AVR? Harman Kardon? Pioneer? Not many Class D AVRs around. Many AV receivers get warm because of the HDMI board.

 

[treesey]

I first tried it not bi-amped - which is when I noticed it generates heat - and am trying it bi-amped to see if I can tell any difference in the SQ.

The AVR is the Pioneer SC-LX87

But the heat thing was an aside - I am interested in any info on good Class D subwoofers; searching on the interweb doesn't easily throw out that level of info.

 

[Al ears]

Try NOT bi-amping the 753s from the AVR. It’s just over complicating things, and it’s all coming from the same power supply anyway - any major benefit from bi-amping will come from separate amplifiers with separate transformers. Despite using fairly budget drivers, the 753s are quite demanding, so this may be adding to the demand on the amplifier.

What is the AVR? Harman Kardon? Pioneer? Not many Class D AVRs around. Many AV receivers get warm because of the HDMI board.

Good answer, I was about to suggest similar regards biamping and this may be why amplifier is getting hot.....

 

[treesey]

well if you want to go down that rabbit hole.... A) see my answer above, and B) if a Class D amp doesn't get hot, then 2x Class D amps should get twice as not hot.

But as I said - it seems Class D do generate excess heat, just not as much as A-B etc etc.

Here's the first entry I found on the subject - please post up something contrary if you like.

https://www.analog.com/en/analog-dialogue/articles/class-d-audio-amplifiers.html

 

[nopiano]

Are there any 'HiFi' good Class D active subwoofers at reasonable prices please?

These SVS models begin affordably, and though I’ve not read every spec they seem to universally use class D. In fact, I think the majority of sub makers do, as it makes sense in a box - and you can usually spot the ones that don’t by the big heat sinks!

SVS Subwoofers

Powered SVS home theater subwoofers unleash the ultimate bass experience for music and movies.

www.svsound.com

 

[treesey]

Excellent thank you - maybe that's why I can't find out if sub amps are Class D or not, because they all are

 

[abacus]

No amp is 100% efficient therefore they will all produce heat, however class D is the most efficient and so will produce less heat than something like AB amps, (As you have found out) so everything is working as it should.
Look at the manufactures descriptions of their subwoofers and you will find most will say what type of amp it is; however most are class D due to the enclosed space they are in.

Bill

 

[nopiano]

Excellent thank you - maybe that's why I can't find out if sub amps are Class D or not, because they all are

Here’s an exception that proves the rule. It’s class AB and if you click on the rear picture you’ll see the heat sink.

C1 Sub Mk2 | ATC Loudspeakers

atc.audio

 

[treesey]

Which implies that the Polk subwoofer I have already is Class D.

But The Polk specs. don't confirm it.

https://www.polkaudio.com/en/product/home-theater-systems/tl1600

Which is why I was hoping someone had already done the legwork.

Any other brands to add to the following that any of you have tried please?

REL, SVS, M&K and even another Polk as they seem to be well regarded, though mostly available over the Pond.

 

[nopiano]

Which implies that the Polk subwoofer I have already is Class D.

But The Polk specs. don't confirm it.

https://www.polkaudio.com/en/product/home-theater-systems/tl1600

Which is why I was hoping someone had already done the legwork.

Any other brands to add to the following that any of you have tried please?

REL, SVS, M&K and even another Polk as they seem to be well regarded, though mostly available over the Pond.

I’d bet money on it being class D. Chip amps in that type of sub cost cents, so inevitably they are chosen for ease of manufacture and low cost.

The brands you list are probably the best known though there are more if you’re looking.

 

[plastic penguin]

In my usual roundabout way of seeking audio nirvana, I've bought another AV Receiver to play various versions of old but recently remixed (or new) music in 5.1 audio, which is why this question is in the HiFi section.

It's a Class D AVR, and it does sound rather good, but it still gets somewhat warm when I rotate the dial towards 11.

So Class Ds still generate lost energy as heat, just not so much as A-B etc.

I was expecting no heat at all - this is excellent, as I can still reduce the electricity bill, AND listen to loud multichannel music, AND heat the house this winter.

Are there any 'HiFi' good Class D active subwoofers at reasonable prices please?

PS I'm bi-amping the Mission 753s from the AVR as main L and R, and they respond nicely to 220W per channel into 6ohms

Please forgive me for saying this: why are people so hung up about the class of amplification? I don't give a monkeys if it is class A, A/B, D, G or valve.

I've owned Hi-FIs since 1976 and it's all about matching amplifier with speakers. Get that right, regardless of class, and you are home and dry.

Sometimes people try to over complicate the scenario

 

[Al ears]

Please forgive me for saying this: why are people so hung up about the class of amplification? I don't give a monkeys if it is class A, A/B, D, G or valve.

I've owned Hi-FIs since 1976 and it's all about matching amplifier with speakers. Get that right, regardless of class, and you are home and dry.

Sometimes people try to over complicate the scenario

I would quite agree.... Up to a point.
Those that are concerned with electricity consumption are not going to go all out for a valve amp and / or something that is Class A

 

[treesey]

Please forgive me for saying this: why are people so hung up about the class of amplification? I don't give a monkeys if it is class A, A/B, D, G or valve.

I'm not hung up about Class - but I am hung up about burning the planet away.

So IF you have to buy something , all things being equal, why not choose something that uses less power? Not complicated. You must have misunderstood my question

 

[shadders]

I'm not hung up about Class - but I am hung up about burning the planet away.

So IF you have to buy something , all things being equal, why not choose something that uses less power? Not complicated. You must have misunderstood my question

Hi,
I did the same, initially using class AB amplifiers for my active speakers, then implementing class D, to reduce the total power consumption, even in idle.

Is the amplifier hot or warm ?

There is a lot in the unit, and it seems that the processing etc., is at the top and the amplifiers are at the bottom of the enclosure. Maybe it is just the accumulation of heat at the top ?

Looking at the manual, standby power is 0.1watts, but the total power used is stated to be 370watts. Looking at the power per channel, 1 channel into 4ohms, states the power is 260watts.

So, this unit despite having class D does use a reasonable amount of power.

Maybe obtain a power meter and plug the amplifier into it to see the power used under the conditions you use it in.

Regards,
Shadders.

 

[treesey]

Compared to the previous Yamaha, in the same 'space' in the rack, the Pioneer is nowhere near as warm, and this was after a decently loud test with Steve Hackett's recent Live 5.1 BluRay as the source. As you say, there is a lot of kit in the box, and even HiFi nuts can't argue with the Laws of thermodynamics.

I just expected it to be 'cold' - me not clever.

 

[Gray]

I just expected it to be 'cold'

...Bit like LED when compared filament bulbs.
Loads less energy wasted as heat - but certainly not none.

I'd expect your in-use consumption to be quite a bit below the quoted 370, even the 260 watt figure.
Maybe you'll prove that with the use of a power meter, as suggested by Shadders.

 

[davidf]

As I say, HDMI boards produce heat, and some produce more than others. The Pioneers did get quite warm (I have owned a number of models in the past), but not as warm as any Class AB based AV receivers I’ve owned. Except for the big boy SC-LX91, that got hot (as I’m sure Gel will attest to). Onkyo we’re the worst for this, and I believe newer 2.1 boards run a little warmer than previous ones.

As much as it is nice to help the planet, whether you choose Class AB or Class D will make zero difference In the grand scheme of things. Your receiver is probably using less electric than a slot machine in a Vegas casino on a weekly basis.

 

[splasher]

Depending on how long you use your gear each day, the standby consumption is probably equally important. The other aspect I've considered, but not too closely, is leaving the network connection powered up permanently. All three of my music boxes have the option of full standby or standby with live network connection so you have app control at all times and fast startup. I use the latter for convenience but it will inevitably meaning I am consuming more power than the stated standby level.

 

[treesey]

As much as it is nice to help the planet, whether you choose Class AB or Class D will make zero difference In the grand scheme of things. Your receiver is probably using less electric than a slot machine in a Vegas casino on a weekly basis.

But that's the common misconception - 'what I do will make such a small difference, it's not worth bothering.'

It's the cumulative effect that is critical. So if most people only boil the required amount of water, it has a massive effect. If we had LED bulbs in most houses. Building insulation improved. Think as a society rather than waste power/water/anything.

I asked a friend many years ago why he didn't bother recycling any of his rubbish, separating things out.... 'What I do won't make any difference.'

 

[treesey]

Depending on how long you use your gear each day, the standby consumption is probably equally important. The other aspect I've considered, but not too closely, is leaving the network connection powered up permanently. All three of my music boxes have the option of full standby or standby with live network connection so you have app control at all times and fast startup. I use the latter for convenience but it will inevitably meaning I am consuming more power than the stated standby level.

Again - standby/convenience to me is a 'modern' disease. I switch all of my stuff off at the plug if I'm not using it. Including the internet router off at night. Couldn't care less if it gives me a better 'something' if I leave it on all the time. It's fit for purpose as it is.

How long do I have to wait for it to kick in from 'cold'? Seconds..... oh no!

 

[davidf]

But that's the common misconception - 'what I do will make such a small difference, it's not worth bothering.'

It's the cumulative effect that is critical. So if most people only boil the required amount of water, it has a massive effect. If we had LED bulbs in most houses. Building insulation improved. Think as a society rather than waste power/water/anything.

I asked a friend many years ago why he didn't bother recycling any of his rubbish, separating things out.... 'What I do won't make any difference.'

Not many things for us to enjoy nowadays. Do your recycling, boil the right amount of water, wear a jumper instead of putting the heating on etc etc - just get what you want hi-fi wise and enjoy it, especially if it’s your main or only hobby. It’s like never treating yourself to the odd cake or something nice because you’ll add a few pounds.

We could get into the argument that the planet doesn’t need saving. The planet will survive whatever we do, and will still be here and flourishing billions of years after we’ve gone - what won’t survive is us.

 

[Gray]

I asked a friend many years ago why he didn't bother recycling any of his rubbish, separating things out.... 'What I do won't make any difference.'

About 95% of my waste is recyclable - and I always put it in the separate bags.
Someone who knows a collection employee - told me they bury everything together!....whether or not that info is true, it has stopped some locals bothering to recycle 🤨

 

[treesey]

Not many things for us to enjoy nowadays. Do your recycling, boil the right amount of water, wear a jumper instead of putting the heating on etc etc - just get what you want hi-fi wise and enjoy it, especially if it’s your main or only hobby. It’s like never treating yourself to the odd cake or something nice because you’ll add a few pounds.

you are mixing two things up there - making a bit of an effort when you can vs wearing a hair-shirt and doing nothing.

Having HiFi at all is 'treating yourself to the odd cake or something nice' vs what many people have in the world. All I'm saying here is 'make the cake in a more efficient way'.

We could get into the argument that the planet doesn’t need saving. The planet will survive whatever we do, and will still be here and flourishing billions of years after we’ve gone - what won’t survive is us.

I'm a Geophysicist - I know the planet will probably survive, and more importantly, understand the changes that have happened over geological time.
What won't survive (due to our actions) is the billions of other creatures, most of which make it possible for humans to survive, and as a by-product make the planet astoundingly beautiful.

 

[davidf]

you are mixing two things up there - making a bit of an effort when you can vs wearing a hair-shirt and doing nothing.

Having HiFi at all is 'treating yourself to the odd cake or something nice' vs what many people have in the world. All I'm saying here is 'make the cake in a more efficient way'.

Says the man running 5.1 for music
The Pioneer is rated at 370w, whereas the Anthem MRX520 I’m currently using is 365w (albeit a 5.1 amplifier). My usual Yamaha DSP-Z7 is 500w. The Pioneer isn’t necessarily low for an AV receiver, but I suppose it is low for its output (the Anthem is 100wpc and the Yamaha 140wpc).

I'm a Geophysicist - I know the planet will probably survive, and more importantly, understand the changes that have happened over geological time.
What won't survive (due to our actions) is the billions of other creatures, most of which make it possible for humans to survive, and as a by-product make the planet astoundingly beautiful.

I’m more of a gynacologist myself…

Certain life forms will survive - sharks have been around for about 400 million years, so I doubt they’re going anywhere soon. “Life finds a way”. Maybe there will be a few human survivors - the likes of Bill Gates and Elon Musk, those who can afford to survive no matter what - not necessarily them, as they‘ll be dead by that time, but the mega rich who replace them in the future. Money finds a way too.