Originally Posted by MKtheater
Why do you have the JBL pro sensitivities so low, the ones I used were almost 10 dBs more sensitive than my JTR triple 8's which were rated at 96 dbs at that time. ... Is it because they are 4 ohm or something, so are the JTR's. The only speaker I have heard with better dynamics than the JBL pro speakers were the BFM speakers. Of course the JBL pro's had great dynamics down to 40hz where the BFM's went to about 100 dBs, both in room.
Yes, it's because of the 4 ohms, and manufacturers choosing to play fast and loose with their specs (although JBL Pro does better than most).
My comment in the JBL 4722N's sensitivity cell is: "stated 104db sens is for in-room and not normalized for 8ohm."
Let's look at two speakers: JTR Triple 8, and the JBL Pro 4722N. Both are 4ohms.JTR Triple 8
Stated Sensitivity: 98dB (1w 1m full space)
As they're already stating it in full space, and they used 1w, instead of 2.83v, it's already comparable to 8 ohm speakers using 1w/2.83v. We don't have to adjust its sensitivity.JBL Pro 4722N
Stated Sensitivity: 104dB (2.83v 1m)
I believe this is in-room, so adjust sensitivity down ~3dB, to 101dB.
They use 2.83v, so when comparing to another 8ohm speaker measured at 1w, one would be led to believe the JBL's sensitivity was higher than it really is. So we drop the sensitivity down another 3dB, to 98db.
The discussion about impedance normalization was started around post #219 and was resolved in post #245.