Originally Posted by Kilian.ca
The CM9 at 89dB is about average sensitivity and 95dB at 4m requires about 64W. The Klipsch would give you 107dB for the same W and distance, who listens at that level? To say 89dB isn't very efficient is overstating the case.
At four meters, a speaker with a sensitivity of 89dB would suffer falloff of, at minimum, of 12dB which would work out to 77dB, not to mention the loss suffered by reproducing sound into the open nature of most listening venues which open out into hallways and kitches. Stating the obvious, any close proximity speaker reinforcement, would not be added back in until after the room and distance falloff is subtracted.
I spec my Klipsch, Epic, CF-3's, which are rated at 100dB, 1w/1m at 86dB at 1w/4m. When a movie track is cranked up to 0dB, set by Audyssey, MultEQ XT, the dialogue/action sequences are sound meter measured at 85dB-95dB (main listening position) as I've not measured for peak sound levels with explosions and such. The point, our measurements mirror expectations based on specs that are based on realistic falloff due to the open nature of the room and the distance of the main listening position from the speakers.
The point, you're correct when you post that 89 dB at the main listening position is not inefficient but to say that one who has a speaker system that has a sensitivity rating of 89dB, 1w/1m is going get 95dB with 64w's of power, is overstating the case. As to listening at 107dB (and you know this
) considering the THX reference level is 85dB - 105dB and the subwoofer standard is 115dB, I'd say pretty much everybody who goes to their local movie theater to watch a quality action flick is doing what you suggest.If I've missed anything, please straighten me up.
The calculator above says one will have r77dB if a stated sensitivity of 89dB, 1w/1m. One would need 128w to reach 98dB, not counting reduction for room size and loss due to bleeding into hallways and the kitchen; contemporary, open room, architectural design. The point of my above efforts is not to bag on the CM9's but to realistically take into consideration room configuration and main listening position distance from speaker setup and what amplifier requirements one would reasonably expect to need if working towards THX reference listening level standards; proper speaker/amplifier match-up for expectations.
If THX reference level listening levels is the expectation, and one doesn't want to feel they're missing out, then, if using these speakers, they should give consideration to picking up a pair of 500w monoblocks, plug them into a dedicated 20A circuit to prevent current sag during reproduction peaks. If this is not their stated goal, then they'll be happy as a clam in a tidal zone using the ~125w's a 4311Ci is capable of reproducing, five channels being driven, to power these speakers with.
The above said, personally, my opinion, using these speakers, coupled with this AVR, I find the 4311Ci to be underpowered if one is expecting a consistent THX reference level listening experience. My personal philosophy is, never use more than 80% of what a piece of gear is rated for if you want things to last. In this case, using these speakers, to consistently reach THX reference levels, the amplifier section of the 4311Ci falls a few watts short of a full load, necessitating the addition of an outboard amplifier. Using this 80% standard, agreeing with you, using our 11dB more efficient Klipsch speakers and our AVR of choice (Marantz, SR5007), despite easily reaching THX reference level listening levels, one would be well served by the addition of an Emotiva, XPA-5; 200w x 5. Using the CM9's for mains, one would be well served using, at minimum, an Emotiva, XPR-5: 400w X 5.
The purpose of my exercise is to elucidate and eliminate the nagging doubts one has, when wondering or asking if one is missing out.
Question: "With these speakers, married to this AVR, am I missing out?"
Answer:.. "Not if you add a quality, powerful, outboard Amp."
Answer:.. "See my above last few posts."
-Edited by BeeMan458 - 10/14/12 at 6:49am