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Robin
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Last seen: 2 years 10 months ago
Joined: Feb 4 2012 - 4:51pm
distortion on my system

Hi all Expert

Newbie here. Currently, just hook up a system consist of integrated amp Audiolab 8200A (60w), PMC  DB1i standmount speaker and marantz CD 6004, interconnect is Cord Cobra and speaker cable is Qed XT evolution and a power cord for integrated amp under Chord company (Superscreen).

Alll the above is under one/two month old. I suppose still under run in. The music is smoothing in vocal. However, when I crank up vol  listen to pop/rock music, i find that there is distortion.

Would like to know is it the amp not enough power. If yes, should i bi-amp my system by adding a power amp? how many watt should I match my integrated amp (pls dont ask me to change as I just brought the amp). Any  recommendation other than audiolab brand under $1000 (US)

jackfish
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Joined: Dec 19 2005 - 2:42pm
It is possible you are driving the Audiolab 8200A

into clipping. The PMCs have relatively low sensitivity. You could run an 8200P on the low frequency section of the PMCs with the 8200A taking the high frequency section in a biamp configuration. Or you could just use the 8200A as a preamp and try an Emotiva XPA-2 or a pair of UPA-1s. You can return either within 30 days for a full purchase price refund if they don't work out.

http://www.hometheaterhifi.com/power-amplifiers/496-a-secrets-power-amplifier-review.html

http://www.tonepublications.com/review/the-emotiva-usp-1-preamplifier-and-upa-1-amplifiers/

Robin
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Joined: Feb 4 2012 - 4:51pm
Thanks for your reply Before

Thanks for your reply

Before I make any movement, can i know more on clipping. I tot when amp clip there is no sound from speaker.. before purchasing should i take note on the gain. must the gain match my current amp.

jackfish
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Clipping is audible.

Yes, a close match in amp gain is advisable when biamping. With the Emotivas I would forego biamping and use the 8200A as a preamp.

JIMV
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What kind of distortion?

What kind of distortion? Clipping is not distortion...

commsysman
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Distortion

Clipping is the most severe type of distortion. It occurs when the peak of the waveform tries to exceed the available power supply voltage, so the top of the waveform is completely missing. You can't get much more distorted than that!!

For example, suppose an amplifier has power supply voltages of +30 volts and minus 30 volts in the power amplifier output stage. You might be able to turn the gain (volume control) up to where the input voltage times the gain is equal to 80 volts peak-to-peak.

The amplifier can only go from +30V to -30V, so that is 60 volts peak-to-peak and the waveform peak will be flattened off during the time that it is trying to go higher but can't.

This is severe distortion which is highly audible!!

 

Your current speakers are rated at a sensitivity of 87db per watt at 1 meter. 10 watts will then produce a sound level of 97dbA from them, and 60 watts will produce a sound level of approximately 104 dbA at clipping from them, beyond which distortion will be very bad. 

This is very very loud. I don't know how loud you are trying to listen to rock music, but some people do try to go louder than that.

Doubling the amplifier power will give you 3db more, which is not that much, so going to another amplifier does not make much sense unless you go to 250 watts or higher.

Changing to speakers that are 6db/watt more sensitive would have the same effect as 4 times as much amplifier power, so that makes a lot more sense. (3db is twice as much, 6 db is 4 times as much, 10 db is 10 times as much, etc.)

Get some speakers that have a sensitivity of at least 93db per watt, and the amplifier you have should be all you need.

The Klipsch Synergy F-30 speakers have a 97db per watt sensitivity. That is 10db better than your current speakers, which would give the same sound level with your current amplifier as if you kept your current speakers and installed a 600 watt per channel amplifier.

Many Klipsch speakers are very sensitive designs.

The botton line is that if you want to go 10db louder than you can now, you either need 10 times as much amplifier power or speakers that are 10 db per watt more sensitive. Either one will have the same result.

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