LM3886 clipping behaviour

[cs]

I am considering using some LM3886's in some active speakers, and wondered what the clipping characteristics are like. Do they clip cleanly and recover quickly ?

The datasheet shows some horrendous waveforms when the 'Spike' protection is operating, and I wouldn't like to think they behave that way when briefly driven into clipping ?

TIA,
Chris.

[leadbelly]

Yes, the clipping is that harsh. Why is clipping such a big issue for you? What is the efficiency of your drivers?

[MJL21193]

Hi,
I did an active 3-way amp here. It's in use now (I mean right now, I'm listening to Boston) and I can't tell you anything about how it sounds when it clips because I don't think I've come close.
And yes, I like it loud.

Maybe you should be considering ways to avoid clipping in the first place.

[cs]

The drivers will be Jordan JX92S, 89dB/W/m, and I will use two of them per speaker, each driven by its own PA, running off +/-35V.

So, there shouldn't be any clipping most of the time, but there is still a chance that it might occur on large peaks, albeit very briefly.

[leadbelly]

IMHO you're tipping at windmills.

[cs]

Originally posted by leadbelly
IMHO you're tipping at windmills.

Translation ?

[leadbelly]

It's silly to think you need that much power to drive a fullrange speaker.

[cs]

Originally posted by leadbelly
It's silly to think you need that much power to drive a fullrange speaker.

Surely, it's even more important to have sufficient headroom with a full-range speaker, since the amp has to deliver the whole audio band.

The reason for my post is that with modest amp power (50W) and average efficiency speakers, clipping is bound to occur on transients, so it should do so in a benign manner. But if they clip badly (as has been stated above), then maybe I should avoid them.

[ionomolo]

If you aren't worried about the power but only about clipping behaviour you might want to add a soft-clipping preamp that avoids clipping of the amplifier. Tube preamps are the best in that sense but it they usually clip at very high output levels.

[cabbagerat]

Originally posted by cs

The reason for my post is that with modest amp power (50W) and average efficiency speakers, clipping is bound to occur on transients, so it should do so in a benign manner. But if they clip badly (as has been stated above), then maybe I should avoid them.

Not really. Say you like to listen at 86dB RMS, and have 96dB/W fullrange speakers. Normal listening voltage will be about 0.1W, or 0.9V into 8 ohms. Well recorded CDs will have full scale transients, and the signal RMS at -20dB. This will put your full scale transients at 10W, or 9V into 8 ohms, still well below clipping.

Do your own sums with the sensitivity of your drivers, what volume you listen at, and see whether your chipamp is ever likely to clip. Feel free to give yourself more than 20dB headroom if you wish.