Rated vs. Actual Power & Volume Control

alucididea

So, I’ve got a question concerning power.

Let’s say an amplifier is rated to 300w RMS (20-20000hz). Now let’s say my speaker is only rated to 250w. Volume control goes from -80 dB to +16.5 dB. At what volume level would it actually be safe to use this amp/speaker combo?

I’m figuring as long as I don’t turn it above, say -20 or so? Any input would be welcomed.

ZLTFUL

Ignore wattage ratings for speakers.

Frankly, it is misleading.

I have a pair of speakers rated at 100 watts running on a 200wpc amp.
And they will drive you out of the room with volume before the amp is even close to clipping.

Clipped signals is what kills speakers...power will too but it is 90% clipping vs 10% overpowering speakers. *note 78% of all statistics are made up on the spot*

Then there is pre amp and amp gain (or lack thereof), distortion levels, tiny little spider like gremlins that eat small children...

Nightfall

60% of the time it works every time.

BlueFox

Use your ears. When it sounds bad, turn it down. If you feel technical then buy a Sound Pressure Level meter so that you can put a number on what you hear. Of course, this assumes you have ‘normal’ speakers that will let you know they are hurting.

alucididea

ZLTFUL wrote: »

*note 78% of all statistics are made up on the spot*

My thoughts exactly.

BlueFox wrote: »

Use your ears. When it sounds bad, turn it down. If you feel technical then buy a Sound Pressure Level meter so that you can put a number on what you hear. Of course, this assumes you have ‘normal’ speakers that will let you know they are hurting.

I agree with that. I guess I’m trying to create a general rule of thumb for myself.

BlueFox

The problem, to me, is that volume controls have different meanings in different setups. A number in one setup doesn’t necessarily relate to another setup.

alucididea

BlueFox wrote: »

The problem, to me, is that volume controls have different meanings in different setups. A number in one setup doesn’t necessarily relate to another setup.

Fair enough.

mpitogo

alucididea wrote: »

Volume control goes from -80 dB to +16.5 dB.

I would ignore the power (unless it’s clipping). The volume control suggests your preamp is able to calibrate to reference levels. At common THX levels -20db on the volume knob should produce around 85db from the speakers. This is a normal listening level and doubt you would be overdriving and pushing more than a few watts. If you know what your speakers maximum output db is it would be relatively easy to derive the max volume level and compute the power.