Class D Power vs Speakers Maximum

[PloddyPastard]

Good afternoon,

I am reading now through this forum for a couple of months. Great insights and knowledgeable community.

Also stumbled upon a thread discussing Class D Amps (I believe it was Audiophonics with Purify Eigentakt). Looking into the Power of these Amps (was 2x400 Watt) and general Class D Amp power (most are 250 Watt ++) - Iam wondering if these would kill my Speakers. They are 30-150 Watt and 89db.

It is too much of Power for them, or?

Thanks and have a great day.

 

[DVDdoug]

The amplifier class (how it's constructed internally) has nothing to do with it.

It's complicated but yes. If you have more than 150W and you turn it up and use that power, you can burn-out your speakers.

A 150W speaker is supposed to be OK with an amplifier that's hitting 150W on the program peaks, and not clipping. If you play constant 150W test-tones into a 150W speaker you can fry it. Especially at high frequencies because the tweeter can't handle as much power as the woofer.

If you push that 150W amplifier into clipping, the peaks are limited to 150W but the average power still goes up, and again you can fry the speaker. There is a popular myth that it's safer to use a higher power the doesn't clip (which creates harmonics that go to the tweeter) but it's actually more dangerous to use a higher power amplifier that's putting-out the same (or more) average power and higher peaks.

So, it's "statistical" and the "theory" depends on trustworthy specs for the amplifier and speakers.

In normal home situations... speakers are rarely blown unless you're having a party and a drunk person has access to the volume control. Or if "kid" is allowed to turn-up the volume, or if you are testing-experimenting to see how loud you can go. Usually it gets plenty loud enough, or you start to hear distortion and you turn it down.

 

[PloddyPastard]

Thank you! I will than better stay away from these high powered amps. I would not forgive me if killing my speakers. However, still wondering why it seems that there are only few Class D Amps with <250 watt and good chipset. But I might have looked at wrong places and also might be biased.

 

[DVDdoug]

why it seems that there are only few Class D Amps with <250 watt and good chipset.

I don't know what chipsets are "good".

MAYBE because it's cheap and easy to make high-power Class-D amp? If you are selling amplifiers, why not make them high power?

There are some Class-D amplifier chips rated for a few watts.

I assume by AVR has Class-D amplifiers because it's lightweight for something that puts-out about 100W X 5 channels.

Most of the benefits of class D are related to power so there's more reason to use it with high power amps. The MOSFETs (or transistors) don't get as hot so they can use less expensive parts (or fewer of them) and smaller heatsinks, etc. It's also more efficient, transferring almost all of the power from the power supply to the speaker.

Most pro high-power amps (1000W or more) seem to be Class-D.

 

[AnalogSteph]

Note that Class D amps have a tendency to start sounding absolutely terrible once they hit clipping, so them being underpowered is something that you'd rather want to avoid with those.

Speakers also tend to complain quite audibly when overloaded, aside from being VERY LOUD (where do you think the power goes?). Anyone remotely sober would be very much compelled to reach for the volume knob at this point. It's just acutely intoxicated people who tend to not notice - party damage is a classic.

 

[MaxwellsEq]

Good afternoon,

I am reading now through this forum for a couple of months. Great insights and knowledgeable community.

Also stumbled upon a thread discussing Class D Amps (I believe it was Audiophonics with Purify Eigentakt). Looking into the Power of these Amps (was 2x400 Watt) and general Class D Amp power (most are 250 Watt ++) - Iam wondering if these would kill my Speakers. They are 30-150 Watt and 89db.

It is too much of Power for them, or?

Thanks and have a great day.

Welcome to ASR!

This is a classic problem. In general it's a good Idea to have as much amplifier power available on tap as you can afford, simply because that way the amplifier will be operating comfortably without clipping. So the "power handling" specification of speakers is not very useful.

But how much power you put through your speakers only depends on their efficiency and how loud you like your music. In practice, you probably never use more than a handful of watts, even when listening quite loud. So, even a 50,000W amplifier won't damage your speakers as long as you don't turn it up too loud.

Meanwhile a 2W amplifier might increase the risk of damage if you have it playing flat out due to increased distortion.

 

[DanielT]

If you feed 150 watts into a pair of 89 dB sensitive speakers and listen to that SPL level often and for a long time then you will probably have other problems to worry about than some possibly burnt speaker elements.

In any case, blowing drivers that have little power handling is not difficult to do. Just put enough power into them and the inevitable happens:

 

[Hear Here]

Iam wondering if these would kill my Speakers. They are 30-150 Watt and 89db.

It is too much of Power for them, or?

Essentially no - the amp won't damage your speakers unless you wind them up to maximum output.

I use a 300 watt Eigentakt amp to power my 107 dB horns, although the speakers only need a handful amps to reach deafening volumes. My amp allows a maximum volume to be set and I've chosen -20 dB, so no damage will be done, even if someone puts a book down on the remote! With you low sensitivity speakers, you should be OK.

 

[tomtoo]

The question is the same as if i buy a porsche with 600HP can i kill my self more easy than in a other car with 200HP. Its indeed possible, but it has not to be that way. Its all about that place between the ears. If there is all ok you can be absolutly save with a 600HP porsche and with a high power amp at lower powerd speakers.

 

[Sokel]

I would worry a lot more for other elements of a gear chain than the high power of the amps.
Do you think that Genelec's 8361A drivers can stand its total of 1kW?
Or the 6kW of 8381A (no matter how big the drivers are) ?

I would also worry to DSP or RC low's for example filling dips (you shouldn't but people do it any way) not taking into account how much of amp's power they can "eat".
I would also worry about the amps themselves,cause these 400W you mention are usually peak power and you can read in the fine print that continious one is 1/5 or 1/8 of it depending the cooling and thermals,etc.

So don't worry about power,sane use is all it takes and some fail-safes against user-error sudden turn-ups or glitches up the chain is not the worst idea,despite the advertised W.

 

[PloddyPastard]

Thanks for all of your replies!

Indeed Iam not listening super loud very often. Currently I have an amp which provides 80w into 4ohm. That's more than enough and I never had it more than 75 (out of hundred) - however, still no clipping. My biggest fear would be someone connecting to it accidentially and push the volume. A limiter is a good idea - my amp has it as well and it is set to 80.

Cheers