Determining a Spec

[cassanova]

I've seen amps that have 102 db 1 watt@1 meter. Then I've seen them at 98. At what point when reading the spec sheets would this number indicate efficiency or inefficiency?

[Plstrns]

Originally Posted by cassanova

I've seen amps that have 102 db 1 watt@1 meter. Then I've seen them at 98. At what point when reading the spec sheets would this number indicate efficiency or inefficiency?

Speaker or Enclosure, not amp.

If everything else is equal, (it never is) each db of sensitivity equates to a ~10% increase in volume.

[will33]

Originally Posted by cassanova

I've seen amps that have 102 db 1 watt@1 meter. Then I've seen them at 98. At what point when reading the spec sheets would this number indicate efficiency or inefficiency?

I assume you're talking about speakers/cabinets.

Higher number = more sound coming out per watt going in but don't take that as a hard and fast rule. It varies with frequency, a speaker could be 94db in the lows with a spike up top at 105 or something. These numbers are fudged a lot to make products look better on paper. If you're looking at an actual spec sheet with response charts, etc. you can actually tell what you're looking at. If the print in an ad for a cab just says "X db" there isn't much knowledge to be gained from that. It's more likely to steer you in the wrong direction than it is the right one.

[will33]

Search something like "speaker specs" on here. There's a bunch of threads explaining the details with several posts/links to real engineers.

[cassanova]

Originally Posted by Plstrns

Speaker or Enclosure, not amp.

If everything else is equal, (it never is) each db of sensitivity equates to a ~10% increase in volume.

Yeah, I meant speaker/enclosure, not amps. My bad.

[will33]

Rule of thumb is a difference of 3db is a small but noticable change in volume. A difference of 10db appears to be twice as loud (or half as loud if you're going the other way). To gain 3db you have to double power assuming the speaker can handle it. To gain 10db you have to have 10 times the power, again assuming the speakers(s) can handle it. Having higher SPL speakers is cheaper and easier way to get louder than having huge power trashing your speakers. Adding more speakers will get you louder than adding more power. Generalities here, there are exceptions to everything.