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AUDIO FORUMS >> General Discussion and Support >> Klipsch RF 7
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Message started by Dan Soukup on 11/30/09 at 16:09:57

Title: Klipsch RF 7
Post by Dan Soukup on 11/30/09 at 16:09:57

I've recently learned that Klipsch is manufacturing the RF-7 speaker again and while viewing the specs from their website, I see they rate the efficiency as "102dB @ 2.83 volts/1 meter".

My understanding is that the norm is to measure dB at 1 volt/1 meter. So what is the reason for the 2.83 volt measurement? Is Klipsch just trying to make their speakers have a higher dB number, or am I missing something? Is there any way to compare efficiency of the Klipsch to, say, a Decware speaker rated at 93dB, 1 volt/1 meter?

Title: Re: Klipsch RF 7
Post by Jeff on 11/30/09 at 18:22:24

you're probably thinking of 1watt/meter.
i think 2.83v is the equivalent of 1 watt.

Title: Re: Klipsch RF 7
Post by Dan Soukup on 11/30/09 at 19:41:41

Duh! of course. Thanks.

Title: Re: Klipsch RF 7
Post by dank on 11/30/09 at 20:30:23

Be very careful with this one. I think speaker manufactures are going to this spec (2.83v/1 meter) to make their speakers look better than they really are. 2.83v / 1 meter is equal to 1w / 1meter if the speaker is 8 ohms. However if the speaker is 4 ohms, 2.83v / 1 meter is the same as 2w / 1 meter and it only gets worse as the speaker impedance gets less.

A Critical Mass speaker that sells for $2799 is advertised as having dual 1.5 ohm voice coils with sensitivity 96.7 db (2.83v/1m - coils in parallel). This translates into a 0.75 ohm speaker that puts out 96.7 db at 1 meter when given 2.83v. This 2.83v into 0.75 ohms is 10.68 watts! So the spec should be "96.7 db (10.68 w/1m - coils in parallel)" which would be equivalent to 88.4 db (1w/1m - coils in parallel).
Note: 88.4 db = 96.7 db - 10log10.68

DanK

Title: Re: Klipsch RF 7
Post by rmt on 12/06/09 at 04:04:31

I have the Nibbelin speakers and a pair of klipsch rf-7s. I have done an A/B testing between the two switching between a single source. The Nibbelin NFX is supposed to be 96b speaker, at least when Decware builds them. I built my own so I suppose they could be anywhere from 92 to 102db. Point is, the Klipsch sounded at an equal volume to the Nibbelins during the tests. No measurements, just a subjective observation that the RF-7s are very efficient. We also tested a set of Klipsch that were supposed to 6db less than the RF-7s and they sounded like it too.

btw, the Nibbelins sound much better. I would buy a pair of MG944s or radials long before i would purchase the Klipsch, especially because of the price. I have several pairs of Klipsch but I bought them before Decware got serious about speakers and began offering the variety they have now. Gave the Klipsch to my kids, but even they covet my Nibbelins NFXs and would trade in an instant.