|
Speaker Asylum General speaker questions for audio and home theater. |
|
|
|
Speaker Asylum General speaker questions for audio and home theater. |
|
In Reply to: Loudspeaker sensitivity question. posted by Borough33 on March 24, 2007 at 21:45:44:
In general theough two spkrs in a room give us at least another 3db even at 2-3 metres, so the theory below is a good RoThumbBut the output of an amplifier for this question is best understood in terms of dbw a 200 watt amp having about 22dbw you add that figure to the speakers sensitivity number and get the peak output 'before clipping'. With an 89 db/w spkr @ 1 metre you have 111 db before clipping.
But many spkrs compress dynamics under hard drive which your numbers would be indicating. 6db loss does seems like a lot to me and I'd doubt that a spkr already limiting as 200 watts is approached could go much louder anyway.
Into a 4 ohm spkr 325 watts is only about 24 dbw, and the spkr would only need to be about 81 db/w IF it doesn't itself peak-limit under heavy drive.
The RoT is to figure how much power p.c. you need to get the peaks you want and add 3dbw to that IE double it. OR if your amp has 3db or better peak headroom than you needn't double the power!
A recent article showed that the effects on driver TS par's and FR of entire encl's from heavy drive is not as big as supposed, but I don't think it covered dynamic compression, as the VC's heat up, or even when they are still running relatively cool.
The db/w plus amp's dbw as a calculation 'holds best' IME for spkrs with sensitivities above 90db which are also efficient. These generally don't need high power although many CAN use it, without compressing.
I would not consider a 4ohm spkr to be efficient AND sensitive unless it exceeded 94db/w sensitivity and was an EASY 4 ohm load never falling below 3.5 ohms even under heavy drive.
Note that MANY 8 ohm nominal spkrs are 'sensitive' - 90db/w or better - but have impedance minima below 3 ohms along with highly capacative phase angles and need far more power than the formula I've mentioned would indicate.
famously most of the Wilson Watts / Puppies, more counter intuitively most of the newer Tannoy multiways - with the tulip guide horn in the dual conc. driver - are amp punishers! Both are quite sensitive but they can sure sink power.
IME the only risk to spkr drivers from high power amps is when you are playing around with connections and forget to turn the pre-amp down or the power amp burps anyway!
WarmestTimbo in Oz
The Skyptical Mensurer and Audio ScroungerAnd gladly would he learn and gladly teach - Chaucer. ;-)!
'Still not saluting.'
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- well there acouple issues here, lsitening distnce being one, most of us listen at least 2 to 3 metres away or more! - Timbo in Oz 21:10:11 03/26/07 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
