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WHAT'S THE DEAL WITH WATTS?

I'm considering acquiring a new (for me) integrated, under $2k, to drive my KEF full range speakers. They are very efficient (93db) , 4ohm and rated for 50 - 200 watts.  It seems that a good amp with 80 or 100 watts per channel at 8 ohms will take these speakers to any volume I'd want to experience in my medium sized living room.  So what advantage/benefit in sound am I going to get with 150 -200 watts, or more, per channel? Is it worth spending more for extra power that will never really be demanded?  
larstusor
willland's avatar
willland
846 posts
 
I would say the benefit of more(quality) watts would be headroom.  Some specifics like how loud you listen and how large/small your room is should determine if you "need" more watts than 80/100 watts.

I have a Yamaha A-S1000 integrated amp with "only" 90w/ch and let me tell you it is the most potent 90w/ch I have ever heard/owned.  This thing is a beast at 48.5 pounds and it does not even break a sweat driving my Klipsch RB-75's(97dB) at ear bleeding levels in my 5000ft3 room.  I know the 75's are bookshelf speakers instead of full range but they do bottom out in the mid 40Hz region.

Bill
lowrider57's avatar
lowrider57
5,393 posts
 
Going from 100 wpc to an amp with 150 to 200 wpc/8 ohms is not a significant increase in power. In terms of SPL, with 200w you would gain 3dB.

A high current amp with 80 or 100 wpc would be a better performer than simply going for higher wattage. High current amps will have better control over impedance demands from the speakers, in your case 4 ohm speakers.
lowrider57's avatar
lowrider57
5,393 posts
 
I should add that since your speaker's impedance goes as low as 3 to 4 ohms, an amp that doubles it's power rating would provide you with high current. For example, an amp rated at 100 wpc/8 ohms, 200 wpc/4 ohms.
The plus side of your KEF's is the high sensitivity of 93dB, so I would say you don't need to look for a high wattage SS amp.
You could also try tubes, although the reviews I've read are using SS.
mesch
3,402 posts
 
+1 Lowrider.  Look for a quality amp that doubles down in watts from 8 to 4 ohms. I run a BEL 1001 MK5. It is rated at 50 into 8ohms, 100 into 4, and 200 into 2. It will drive many speakers better than many 100 wpc amps will.  
paraneer's avatar
paraneer
818 posts
 
I’m considering acquiring a new (for me) integrated, under $2k, to drive my KEF full range speakers. They are very efficient (93db) , 4ohm and rated for 50 - 200 watts. It seems that a good amp with 80 or 100 watts per channel at 8 ohms will take these speakers to any volume I’d want...

I agree with others regarding an amp that can produce high current and preferably double down in its 4ohm power output. Or at least come close.

You know the speakers are 4ohm rated, yet you say that an amp that is rated 50-200 wpc into 8 will get the job done??? Not necessarily if the amp does not have its 4ohm specs published. It could have a compromised power supply and not be able to generate the current needed to be stable at 4ohms. Just make sure the amp has a 4ohm rating too and because the KEF’s have high sensitivity, you’ll have no problems. There are lot of good ones out there in your price range.

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