Speaker matching

Almost Enough · 10-29-2009, 01:08 PM

When choosing a speaker for an amp, is it ok to get a wattage that's just a little under what the amp puts out?

For example, if I were to get a 25w Celestion greenback 16ohm to put in my Peavey Classic 30, that runs max at 30w at 16ohms, will it be bad for the speaker? I hardly ever run the thing more than 5 on the volume knobs.

Folk_guy · 10-29-2009, 03:50 PM

If you're careful not to crank it up all the way you will be able to get by, but it's a lot less risky to replace the speaker with one of the same or a little higher wattage. If you do go with the smaller wattage speaker be careful to turn down if you start hearing the speaker distort of break up.

Major Tom · 10-29-2009, 05:34 PM

You should be fine unless you are cranking it with a really distorted tone. The more distortion and/or compression, the heavier the "duty cycle"; i.e. when the attack of a note / chord is about the same volume level as it is during the sustain or decay portion of the envelope, the average amount of current to the speaker is high. Like some of the "metal" presets on modelers. With a pristine clean signal, the attack is very high, but it drops off very quickly to a fraction of that level, so the average level hitting the speaker is only a fraction of the amp's output. Mild OD, edge of distortion, etc. are somewhere in between.

I would guess that you are not hitting any where near 30 watts, except maybe the transients.

With a speaker, it is more about the average of power they are receiving over a period of time, not transients so much unless it is a really exaggerated situation, like a 10 watt speaker with a 100 watt amp, where a transient at full power could instantly blow the voice coil to bits. In addition, British speakers used to be known for under-rating their speakers by a substantial amount - whether that was fact, or old wives tale....

IMO, you are fine.

Walkeraviator · 10-30-2009, 09:43 AM

I have heard that over watting your speaker like putting a 75 watter n a 40 watt HRD will increase yoru headroom, but havent tested that theory so dont know for sure.

***BillSPrestonEsq*** · 10-31-2009, 06:43 PM

Quote:

Originally Posted by Walkeraviator

I have heard that over watting your speaker like putting a 75 watter n a 40 watt HRD will increase yoru headroom, but havent tested that theory so dont know for sure.

it prevents you from getting speaker distortion.