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Sensitivity 86 v 90

I am considering an upgrade from speakers with a sensitivity rating of 90 db, 4 ohms, to larger speakers rated at 86db, 8 ohms nominal.  Same brand, PMC. My tube integrated amp is 80-112 watts triode/ultralinear, and it’s fine for my 90 db speakers.  Although, it is sometimes at around 4 o’clock on the volume control, approaching the max at 6.  I am aware of the “amp power must double for each 3db increase in volume” rule of thumb, but really have no practical experience with this.  I do like having 90 db efficiency, always assumed that meant a less powerful amp would suffice. 

   My question is, would the decreased efficiency be a concern? 

lloydc

Showing 3 responses by ditusa

ditusa's avatar
ditusa
2,056 posts
 

@lloydc Wrote:

Sensitivity 86 v 90

My question is, would the decreased efficiency be a concern?

No!

The two speakers have the same efficiency. Changing the impedance of the speaker will change the voltage sensitivity, not the efficiency -- the 4Ohm speaker is getting 2 watts from the amp, the 8Ohm speaker is getting 1 watt from the amp. That’s why the 4Ohm speaker has a 3dB higher sensitivity. (Ohm’s law) Sensitivity and efficiency are not the same. See below: Paragraph C. Hope that helps.

Also, what is the gain of the amp you have?

Mike

 

 

ditusa's avatar
ditusa
2,056 posts
 

@lloydc Wrote:

My integrated amp (Rogers EHF 200 Mk 2) has 40 db of gain. 

That is a nice amp, you have plenty of gain. What phono preamp do you have?

Mike

 

 

ditusa's avatar
ditusa
2,056 posts
 

@lloydc Wrote:

  I do like having 90 db efficiency, 

I like having 2.7% efficiency and 96 dB sensitivity! 😎

Mike

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