From david@glover.com.au Wed Sep 04 05:28:56 2002
Subject:Re: Sound system

Hi Marc,

The risk isn't so much to your amplifier as to your speakers, for (at least) two
reasons.

Because hifi speakers are designed to reproduce "music" with a broad range
of frequencies, the high frequency speakers ('tweeters') normally have a
relatively low power rating - consistent with the high frequency content in
music.

A keyboard can drive an amplifier to full power at a very broad range of
frequencies - so you can end up putting the amplifier's full power into a
tweeter designed to take maybe 20% of it's power. Result: blown tweeter.

The other potential problem comes from the wide dynamic range: high output
levels from keyboards can overload an amplifer, sending into "clipping". The
clipped signal puts a very heavy load on the speakers, which are typically not
designed to take the amplifier's full output power, least of all with this sort of
signal. Result: damage.

Often this dynamic range is in the transients (particularly on the attack of an
electric piano etc), so the peaks are heavily distorted.

Most amplifiers will accept being driven into overload for short periods
(though long term they'll be damaged by overheating). Speakers will either
overheat or mechanically fail - often very quickly.

Musical instrument amps/speakers are designed to tolerate this: speakers are
typically more robust and amplifiers can dissipate the heat from being driven
heavily.

I hope this clarifies it. Your home sound system is fine as long as you're VERY
careful not to overload it (at the first sign of distortion, turn the volume down).
An instrument amplifier will do a better job in the long term.

David

--- In CloneWheel@y..., Marc Azar wrote:
> I'm about to inherit a small 25 watt bass amp for my BX-3. Meaning that
> so far my output went through my home sound system. Yes, I know. I
> received a commentary emanating from a professional musician recently on
> which I would like to enquire. He strongly suggested that a new sound
> source should be made available as keyboards tend to have peaks when
> played and this could damage the amplifier from the home system. Is this
> true? I'm not enquiring about quality of sound here and yes, following
> past threads, I have learned a lot about the impossibility of
> substituting the original sound of Leslies, and the next best things od
> Speakeasy's, Mackies SM450 and Motion Sound products, etc..
>
> Marc Azar