volume increase

[alabama83]

Hi, 
I have recently purchased the rp600m speakers, with 96db of sensitivity connected to a 220W musical fidelity M6 amplifier.

Compared to the previous 86db speakers I expected that at part of the volume of the amplifier, I would have had a higher volume, instead with the rp600m I have to significantly increase the volume of the amplifier to have the same volume as before, even if the db are well 10 more. Why?

Thank you 

[MeloManiac]

https://www.musicalfidelity.com/products/m6series/m6si

 

Were your 86db speakers 8ohm too, or rather 4 , 6 or 16? That may explain it possibly.

 

As the RP600M speakers have a 96db efficiency, they should indeed play louder than speakers rated 86db efficiency at 8 ohms, so something is not right. Make sure you check your connections (source to amp) and the cables you use.

[capo72]

Make sure one speaker is not out of phase, which would significantly reduce overall output. 

[BadChile]

FWIW, the Stereophile review of the RP-600 from March, 2019 suggested a measured sensitivity of 89.6/2.83V/m.

[alabama83]

The previous ones were 88 db on 8 Ohm, not 86 sorry.

The links are correct, may it be because they are new?

[alabama83]

I have heard the opinion of other owners and they all encounter this problem,  it would seem that the 96 db declared are not at all true

[garyrc]

On 9/9/2020 at 1:12 PM, BadChile said:

FWIW, the Stereophile review of the RP-600 from March, 2019 suggested a measured sensitivity of 89.6/2.83V/m.

@alabama83

 

If 89.6 is the true sensitivity, your new speakers should be 1.6 dB louder (1.6 just noticeable differences) than your old ones..

 

Klipsch's sensitivity ratings are for performance in a typical listening room, rather than in an anechoic chamber.  Such a room should add about 4 dB to the sensitivity.  So, if the above is correct, your in-room sensitivity should be about 93.6 dB, 1 W (2.83V into 8 Ohms), at 1 M.  Some room gain and boundary gain would add more, some less.

 

Putting the speaker near a wall, or in a corner may increase the apparent sensitivity and the SPL.

 

How all this works, or doesn't, can be seen by looking at the Klipschorn.  When Klipsch started measuring sensitivity (in the 40s??) hardly any speaker company had a (good) anechoic chamber.  My 1958 book Hi Fi by Martin Mayer doesn't have a single sensitivity rating in the whole book.  In the 60s, the Klipschorn was rated as 104 dB at 4 feet, rather than at 1 meter, in a living room.  This was also spec'd as being 54 dB EIA.  To convert that to at 1 watt at 1 meter, add 49 dB.  54 dB + 49 dB = 103 dB, which is what JBL got with one of their 54 dB EIA speakers.  These measurements may have been taken between 500 and 2,000 Hz only, or using a wider chunk of the frequency response.  For the Khorn, Stereophile got 101 dB, but that was on top of a furniture dolly, in a driveway.  Let's say the true sensitivity is 101.  If we were to add 4 dB for being in a room, we would get 105 dB, which is Klipsch's published rating for a Khorn in a room.

 

If Klipsch adopted Paradigm's practice of publishing both an in-room and anechoic sensitivity, that might solve the problem.  

 

 

 

[billybob]

Anechoic chambers do not grow on trees but, are made from them...