Do low powered amps damage speakers?

[Pharos]

This is of great concern to me as I am currently driving (albeit at low volume) B & W 801 speakers with a Sugden A21a amplifier (23 Watts into 8 ohms, 32 watts into 4 ohms). I know that a more powerful amplifier is recommended. So I worry about this, particularly if I may not be noticing clipping. I now see there are some youtube presentations on this subject so I need to check through these too. I am grateful for all your earlier discussions.

In the 70s I used my Nelson Jones 10+10 class A into Tannoy Gold Lancs, and sometimes it clipped. This also occurred when they were used with a Quad 303 at Ravensbourne college to provide music for a dance show. We could hear the clipping, which was at about 50W, and backed of the gain a bit. No damage done.

The vol pot is no real indicator of anything power wise, it merely selects a driving voltage.

What is the sensitivity of the 801? 23W will give you a peak of 13-14dB more than that.

[majex45]

Surely the tweeter is fed through a capacitor that will block any DC?

[Simon11]

In the 70s I used my Nelson Jones 10+10 class A into Tannoy Gold Lancs, and sometimes it clipped. This also occurred when they were used with a Quad 303 at Ravensbourne college to provide music for a dance show. We could hear the clipping, which was at about 50W, and backed of the gain a bit. No damage done.

The vol pot is no real indicator of anything power wise, it merely selects a driving voltage.

What is the sensitivity of the 801? 23W will give you a peak of 13-14dB more than that.

The 801's are apparently
8 ohms nominal throughout range
i just looked them up, they are apparently 85 db according to the brochure - I must check the back. I thought they were 87db but that is the later series 2

[dave2010]

Surely the tweeter is fed through a capacitor that will block any DC?

I wondered about that too.

Referring back to this link - https://mackie.com/blog/what-clippin...a=MXxZfDB8WXww from an earlier post in the thread (posts 6 and 15), although this seems plausible I rather wonder if the argument about DC heating and damaging the coils is in fact completely wrong.

Also the argument based on energy is probably wrong too - as most speakers are very inefficient, so the coils most probably are designed to take a fair whack of current before heating becomes an issue.

Has any really serious study been done of this supposed damage to tweeters, or is this all just urban myth stuff based on bad science?

I'm not suggesting that tweeters or even bass drivers have never suffered damage - they sure have - and I've got some bass units to prove it (suspension gave way - though probably through continued use rather than a sudden blast) - but rather that this topic has been picked on by popular writers in "hi-fi" mags who don't know Einstein from Picasso.

[sailor]

@majex45 and @dave2010, Hi guys, Mackie have been around for about 30 years and one would expect to hear some sense from them.

Dave, your suspicion that their explanation is completely wrong is correct. There is no DC component in a square-wave. My post No. 20 addresses both concerns.

[walpurgis]

Did they say 'square wave'? A clipped sine wave is not one. For a brief time each clipped wave has a linear part and I dare say some might describe this bit as DC, if only momentary. I'm not sure what else it could be called.

[Filterlab]

Did they say 'square wave'? A clipped sine wave is not one. For a brief time each clipped wave has a linear part and I dare say some might describe this bit as DC, if only momentary. I'm not sure what else it could be called.

No, at no point in the article did they mention square wave.

[sailor]

Geoff, this may explain it better where graphs are provided. The following is a copy and paste from this link:

https://www.prosoundtraining.com/201...nd-dc-content/

From these graphs it should be well understood that the high frequency harmonic content, and not a DC component (0 Hz), is responsible for the shape of a square wave. In fact, DC by its very definition can not cause any frequency dependent waveform shape. The DC component of a signal is simply the average value of that signal.

[walpurgis]

Geoff, this may explain it better where graphs are provided. The following is a copy and paste from this link:

https://www.prosoundtraining.com/201...nd-dc-content/

From these graphs it should be well understood that the high frequency harmonic content, and not a DC component (0 Hz), is responsible for the shape of a square wave. In fact, DC by its very definition can not cause any frequency dependent waveform shape. The DC component of a signal is simply the average value of that signal.

I shall read that a few times and absorb what I can, although in my previous comment, I was referring to a clipped sine wave and not the formation of a square wave.

[Macca]

I'd guess that Mackie are referring specifically to their own speakers, which are powered, not passive.