"Crank it up" - Cheap AVR's vs Headroom

[bearcreekstables]

Help me out here guys or did I whimp out?

I'm extremely pleased with the clean sound of a recently purchased SVS 5.1 system (SBS-01/SCS-01/20-39 PCi) and so are my friends. I was asked to crank it up over my preferred listening SPL (80dB avg. - 90dB peak) and received boo's for declining. Hey, my low $ AVR is working for me until more money and HT savvy come along.

Being an old stereo buff I tried to explain that lower cost amps don't have the headroom to push the envelope for a number of reasons.

Jerry

[eugovector]

Well, you certainly don't want to distort your amp and damage your speakers. Next time, just juice up your sub a little. That SVS has plenty of power and a little exaggerated bass is usually a crowd pleaser (if the crowd doesn't know better).

[lcaillo]

My experience is that if you turn it up until it sounds bad and back it off a bit you are likely fine. You won't likely damage good quality speakers nor amps with short periods of clipping. It is the folks that constantly push the limits that damage things. Just be aware of temperature on the amp and quality of sound from the speakers and you will be fine.

[bearcreekstables]

Thanks for your sound check advice.

The peak SPL reading stated was for CD's. Request to turn up the volume pertained to CD playback.

Did a follow up SPL sound check on DVD demo used for friends - chapter 3 of: Superman Returns - crystal ship crash landing - measured 105dB peak (volume on AVR set at 50, same setting as used for listening to CD's). DVD passage shakes everything in the house except your teeth.

Replayed the same DVD passage using your sound check advice and started to hear sound break up at 110dB (AVR set at 60).

So, do I have more headroom for CD playback? How much more?

Jerry

[tonyvdb]

bearcreekstables wrote:

Being an old stereo buff I tried to explain that lower cost amps don't have the headroom to push the envelope for a number of reasons.

Jerry

The big bottleneck on lower end receivers is always the power supply if it is not big enough the amp simply wont be able to hit the dynamics at high db's causing distortion. There are several things to keep in mind: One the efficiency of the speakers, Two the Ohms that the speakers run at, And three the amps actual power rating is rarely what it says on the spec's.

[lcaillo]

There is no easy formula. There are too many variables and program material varies too much. The bottom line is, if you hear distortion turn it down. It is rare that you will do damage on a few transients.