Benifits of 120 vs 200 watt amplifier (separates) (1 Viewer)

[Brian Kleinke]

I'm running a set of Polk LSi speakers off of a Sony ES-TA9000N amplifier which I believe is rated at either 110 or 120 watts per channel with VERY low THD.

The speakers are rated at a max wattage of 200, and are considered 4 ohms.

I'm considering upgrading to the Outlaw 7 channel amplifier some time in the coming future and adding a pair of rear surrounds. However what does the extra wattage buy me? Is it purely max output? I've had no issues in my current room of any problems getting it to play really loud. I understand the quality of the amp makes a difference as well, but this Sony ES one seems second to none for quality, just lacks the total wattage of some of the bigger amps.

Any opinions and / or thoughts be appreciated.

Brian

 

[Wayne A. Pflughaupt]

Brian,

The extra power would buy perhaps 2dB of headroom (if that much).

Actually, since your speakers are 4-ohm, the Sony is probably pumping out about 200 watts to power them as it is.

Regards,
Wayne A. Pflughaupt

 

[Chuck Kent]

Wayne's right. You'd gain around 2 more db of volume. Maybe more important is the extra dab of headroom to give a little more cushion against distortion and possible clipping. But 2 db is going to be tough to notice under normal listening conditions...

 

[Chu Gai]

well if you're not hearing any problems, then consider opening up the Brian Kleinke Audio Savings Account and bank your money. bound to have something come up that'll drive you nuts!

 

[Brian Kleinke]

Thanks guys, sounds like it might not be worth it.

I think the Sony is rated at 170 or so into 4-ohms. Perhaps then what I should do is just get 2 of the mono blocks from Outlaw when I want to do 7 channel and toss those on the fronts... or is mixing amps of different rates a bad idea?

Brian

 

[Wayne A. Pflughaupt]

...or is mixing amps of different rates a bad idea?

Not really, although the system will be essentially limited by whichever amp clips first.

Extreme example: 500 watts for mains and rears, 50 watts for center. The center channel will obviously “run out of steam” first, and you really can’t turn the system up any higher than that – no matter how much power the other channels have. Make sense?

Regards,
Wayne A. Pflughaupt

 

[MikeTz]

Be careful just considering the power spec. Speakers that have a nominal impedance that is low (4 ohms or less) require an amp that can deliver significant current. Look for an amp that nearly doubles its power from 8 ohms down to 4 ohms and won't get upset by transient impedance dips that go below 4 ohms. This is a good indicator that the amp will supply the current necessary for your speakers.

Also consider the speaker sensitivity. It takes twice the amplifier power to get the same sound level out of a speaker rated at a SPL of 87 dB/w/m as it does for a speaker rated at an SPL of 90 dB/w/m.

Your Sony goes from 100W to 170W from 8 to 4 ohms and your speakers are relatively efficient (88 dB/w/m) so rest peacefully and consider another use for the money.

 

[Brian Kleinke]

I follow, I've never noticed clipping and I've played back things very loud, -5db or so on the outlaw 950 where the sub has hit 111+db on the THX intro. In this regard clipping is a non-issue so perhaps any mono-block would work fine.

The amp does have the ability to operate in a BLT mode on 2 channels and regular mode on a 3rd, which would allow something on the order of 300+ watts for 2 channels. I guess perhaps I could experiment with this in stereo and see what the difference is.

The general consensus on the Sony ES boards was this sub was only really worth it when you owned a few and ran them in BLT mode. But perhaps this is because these people also ran less efficient more power hungry speakers. Speaker Amplification is the one topic I've never completely understood. The rule of 2x the watts for +3db would seem to make the difference between 100 and 200 watts almost negligible.