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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? 

128x128lloydc
audioman58's avatar
audioman58
3,894 posts
 

Yes it is a issue if you are pushing the volume now ,then you will be running the amplifier into its highest distortion which can damage yours speakers as well as your amp, find a speaker around 90 db there are plenty of them out there 

Even if you have to wait and save more Monies , we’ll worth the wait 

or get rid of the amp and get a bigger one.

carlsbad's avatar
carlsbad
1,551 posts
 

Another thread with a lof of misinformation in it. I especially like the misinormation with exclamation points.

oltexan
35 posts
 

I would be concerned. Tube amps don't usually double in power from 8 to 4 ohms so moving to 8 ohm speakers will probably give you even less total power to work with. Especially if you're already almost max'ed out.

billzame
69 posts
 

Tube amps usually put out the same power into 4 or 8 ohms so that might not make any difference.  But I am surprised that your tube amp has to work so hard to drive your 90db sensitivity speakers.  I have a much lower-powered tube amp driving Vandersteens (sensitivity 86 db) in a moderately large space to volumes higher than I want to listen to.  Perhaps the input level to your amp is too low?

larryi
3,753 posts
 

If the ratings are reasonably accurate (a BIG “if”), the 8 ohm load of the lower efficiency speaker might make it a better match than the higher efficiency speaker.  I generally find that an easy load is more important when it comes to tube amps.

 Not knowing the size of your room, how loud you listen to music, etc., it is hard to speculate on whether you have enough power.  I generally expect 80 watts with 86 db/w speakers would be sufficient; at least I would not rule the amp out.

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