New Amp

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Shapenz

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#175816 12-Jul-2015 22:24

Hi Gzoners,

Currently I have some Kef Q35 speakers that I got cheap off a friend who was using them with a NAD amp but upgraded to some newer speakers - spec:

Nominal impedance: 6 ohms
Power Handling: 100W
Frequency response: 45Hz to 20kHz +/-3.0dB (-6dB at 42Hz)
Sensitivity: 91dB at 1m for 2.83V
Maximum output: 111dB

I've been using a cheap Sherwood amp just to run them for the past year but now I feel it is time to upgrade. I only run a 2.1 setup and have no intention of expanding my home theatre with rear speakers etc.

We use it primary for watching TV series & listening to music so I really just want a good two channel experience - Airplay / networking would be nice but not essential however I would like optical in as that is currently how I run sound out. We do like loud music but don't use these as 'party' speakers so the amp never gets turned all the way up.

The question I have is around the wattages of amps verses speakers. It seems in the sub $1000 range there aren't many amps that output 100w so I was looking at Amps like the slim Marantz NR1504 (http://www.amazon.com/exec/obidos/ASIN/B00BLZDKX2/avrip-20) but from the specs can only do a max of 60 watts per channel.

So, would this be a bad match for the speakers? - Do I need to look some something with a higher wattage? I have also looked at the Yamaha RN500 stereo amp but again this is only 80watts vs 100...

Thanks

richms

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#1341841 12-Jul-2015 22:39

Watts is a meaningless number to compare unless all the other parameters are the same, so an amp that lists 60 watts at 0.005% distortion will probably outperform one that is 140 watts at 10% because its not much more than double, but with way more distortion. It takes double the wattage to get 3dB more sound, which is about where most people recon you can easily notice that it is louder.

Richard rich.ms

elpenguino

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#1341864 12-Jul-2015 23:50

i have been running KEFs for many years. They tend to be a smooth sounding speaker but are not particularly efficient, so you tend to be better off with more power rather than less.

Never hurts to have more power in many machines I suppose! For those times when you do crank it up a bit, lack of power causes clipping which is bad news for tweeters , and saggy bass is bad news for ears.

With amps, specs are often quoted for certain power per channel but check if they actually declare the spec is valid when running both channels at the same time. This is one way to weasel out of a truthful declaration.

I would suggest you need something with a 'true' 80W RMS capability per channel (or more) in 2 channel mode.

Happy listening,
Chris

Most of the posters in this thread are just like chimpanzees on MDMA, full of feelings of bonhomie, joy, and optimism. Fred99 8/4/21

rhy7s

634 posts

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#1341870 13-Jul-2015 02:16

A general rule of thumb is something like half the power for an instrument amp that you want to distort. About rated power for a PA that's intended to run at the rated power of the speakers and all equipment is rated fairly honestly for specified runtimes. Another 50% or more on top when you really don't want the amp to clip peaks and can restrict usage of the volume knob.