125w vs 150w amp

[JDmsz]

I have a Denon x4200w that does 125 watts 2 ch driven and I was thinking about getting a separate amp which is the Emotiva Audio A-300 BasX Stereo Power Amplifier that does 150 watts. Now I'm just wondering would it be an audible difference with Polk audio TSX 550t tower speakers?

 

[lovinthehd]

Doubtful. That gains you less than 1dB assuming equivalent spec for the power, that's not much. Turn your Denon volume knob .5 dB or even 1dB and see if you can readily tell....

ps It takes a doubling of power to gain 3dB

 

[JDmsz]

Doubtful. That gains you less than 1dB assuming equivalent spec for the power, that's not much. Turn your Denon volume knob .5 dB or even 1dB and see if you can readily tell....

ps It takes a doubling of power to gain 3dB

Yes I figured that because I have tried the DB formula and it calculated a .8db gain so I was a little skeptical would it rarely make a difference in sound.

 

[lovinthehd]

Some hear differences just by buying the amp You experiencing issues due to lack of power? I'd think at 91dB sensitivity they'd do fine with the avr's power. Are you running more than just these two speakers? Sub?

 

[JDmsz]

Some hear differences just by buying the amp You experiencing issues due to lack of power? I'd think at 91dB sensitivity they'd do fine with the avr's power. Are you running more than just these two speakers? Sub?

Yeah I have a 5.2 setup. My speakers sounds just fine although they're not lacking any power but I know my fronts could handle way more wattage up to 300.

 

[PENG]

Yeah I have a 5.2 setup. My speakers sounds just fine although they're not lacking any power but I know my fronts could handle way more wattage up to 300.

The 4200 has been actually benched tested by S&V so the data below can be trusted. If you don't need more power, adding an amp won't change anything. If you do need the power, or just want to have lots of headroom to spare, then you can do better with a Crownaudio XLS 1500, for the same money as the A300. http://www.parts-express.com/crown-xls-1502-drivecore-2-power-amplifier-2-x-525w-at-4-ohms--245-508


Read more at http://www.soundandvision.com/content/denon-avr-x4200w-av-receiver-review-test-bench#SlA2HlCcmvZMkJ2w.99

-------------------------------------------------------- 0.1% THD 1.0% THD
Two Channels Continuously Driven, 8-Ohm Loads 124.3 watts 149.2 watts
Two Channels Continuously Driven, 4-Ohm Loads 215.9 watts 239.7 watts
Five Channels Continuously Driven, 8-Ohm Loads 94.6 watts 118.0 watts
Seven Channels Continuously Driven, 8-Ohm Loads 76.8 watts 91.9 watts

Read more at http://www.soundandvision.com/content/denon-avr-x4200w-av-receiver-review-test-bench#SlA2HlCcmvZMkJ2w.99

 

[RichB]

For the record, S&V tests power at 1Khz whereas AH does full range power sweeps.

- Rich

 

[JDmsz]

Thanks guys

 

[PENG]

For the record, S&V tests power at 1Khz whereas AH does full range power sweeps.

- Rich

Rich, you and I should both know the difference between those two test protocols are not that significant when the objects being compared are mid range to high end AVRs from reputable manufacturers, may be 1 dB? Also, I am comparing it with the Emotiva A300, that also specifies: 300 watts RMS per channel; 1 kHz; THD < 1%; into 4 Ohms, though they did use 20-20K for their 8 ohm rating.

I have seen enough bench test data from multiple sources including AH's, Stereophile and AVtech's to say while the 1K vs 20-20K is an important point to make, but it's been repeated so many times to the point it borders on being "overrated". Again, I am referring to mid to high end products made by reputable manufacturers. I do believe there are products that will show much more significant differences between being tested at 1K and 20-20K.

 

[RichB]

Rich, you and I should both know the difference between those two test protocols are not that significant when the objects being compared are mid range to high end AVRs from reputable manufacturers, may be 1 dB? Also, I am comparing it with the Emotiva A300, that also specifies: 300 watts RMS per channel; 1 kHz; THD < 1%; into 4 Ohms, though they did use 20-20K for their 8 ohm rating.

I have seen enough bench test data from multiple sources including AH's, Stereophile and AVtech's to say while the 1K vs 20-20K is an important point to make, but it's been repeated so many times to the point it borders on being "overrated". Again, I am referring to mid to high end products made by reputable manufacturers. I do believe there are products that will show much more significant differences between being tested at 1K and 20-20K.

Power Output (two channels driven)
150 watts RMS per channel; 20 Hz - 20 kHz; THD < 0.1%; into 8 Ohms
300 watts RMS per channel; 1 kHz; THD < 1%; into 4 Ohms

Power Bandwidth (at rated power; 8 Ohm load)
20 Hz to 20 kHz (+ / - 0.07 dB).

Broad Band Frequency Response
5 Hz to 80 kHz (+ / - 1.8 dB).

THD + noise
< 0.02% (A-weighted); at rated power; 1 kHz; 8 Ohms

Signal to Noise Ratio (8 Ohm load)
> 120 dB (A-weighted); ref rated power.
> 100 dB (A-weighted); ref 1 watt.

Minimum Recommended Load Impedance
4 Ohms; which equals one 4 Ohm load or two paralleled 8 Ohm loads.

Damping Factor (8 Ohm load)
> 500.

Speaker Output Connections
Audiophile grade, 5-way binding posts.

Power Supply
Linear power supply with heavy duty torodial transformer.

Correct, they fudged the 4 ohm rating. Others are fudging all loads
I'd lean toward the A/B amp with the better power supply.

ATI specifies both, 1kHz and 20Hz to 20kHz which results in about 50 additional watts into 8 ohms and 25 watts into 4 ohms; Not earth shattering in a 300 watt amp. In terms of DB, there is also dynamic power where an amp with an ample power supply has an advantage.

- Rich

 

[PENG]

Just would like to add that the Denon's 125W per channel rating was in fact for 20-20,000 Hz at 0.05% THD, presumably followed FTC requirements. That looks consistent with the S&V's results though S&V as you pointed out, was done a 1 KHz.

Between 125 and 150W, the difference is approx. 0.8 dB as the OP noted.

 

[j_garcia]

Regardless of the ratings, more power will not make your speakers sound better than they are. As mentioned, if they don't sound strained now, then even +3dB levels of power will make them louder, it will not make them sound better.

 

[lovinthehd]

The 4200 has been actually benched tested by S&V so the data below can be trusted. If you don't need more power, adding an amp won't change anything. If you do need the power, or just want to have lots of headroom to spare, then you can do better with a Crownaudio XLS 1500, for the same money as the A300. http://www.parts-express.com/crown-xls-1502-drivecore-2-power-amplifier-2-x-525w-at-4-ohms--245-508


Read more at http://www.soundandvision.com/content/denon-avr-x4200w-av-receiver-review-test-bench#SlA2HlCcmvZMkJ2w.99

-------------------------------------------------------- 0.1% THD 1.0% THD
Two Channels Continuously Driven, 8-Ohm Loads 124.3 watts 149.2 watts
Two Channels Continuously Driven, 4-Ohm Loads 215.9 watts 239.7 watts
Five Channels Continuously Driven, 8-Ohm Loads 94.6 watts 118.0 watts
Seven Channels Continuously Driven, 8-Ohm Loads 76.8 watts 91.9 watts

Read more at http://www.soundandvision.com/content/denon-avr-x4200w-av-receiver-review-test-bench#SlA2HlCcmvZMkJ2w.99

One slight correction, the 1500 is no longer available, gen 2 model 1502 has the same amp section, tho. Would be my suggestion as well, have four 1500s.

 

[PENG]

One slight correction, the 1500 is no longer available, gen 2 model 1502 has the same amp section, tho. Would be my suggestion as well, have four 1500s.

Thanks for the correction. Good thing the one I linked is in fact the 1502. I still can't believe that $399 thing offers 300W into 8 ohms at less than 0.5% THD and is rated 775W into 2 ohms, that's a lot of current for even the highest but rarest short dynamic peaks found in any kind of music/movies.

 

[RichB]

These power amps may all be sufficient for the speaker or the room. However, humans seem tolerant to some distortions and when an amp clips it also limits.

Here is fun video of powering the Harbeth bookshelf speakers (which are probably inefficient) playing some incredibly dynamic digital music.

WARNING: DO NOT TURN THIS UP!

http://www.harbeth.co.uk/usergroup/forum/the-science-of-audio/amplifier-matching-mismatching-and-clipping-a-curse/2486-how-much-amplifier-power-do-i-really-need

Here is the Pan Sonic "Laptevinmeri / Laptev Sea" track:

Even played at -30 on my system, this is frightening.

- Rich

 

[lovinthehd]

These power amps may all be sufficient for the speaker or the room. However, humans seem tolerant to some distortions and when an amp clips it also limits.

Here is fun video of powering the Harbeth bookshelf speakers (which are probably inefficient) playing some incredibly dynamic digital music.

WARNING: DO NOT TURN THIS UP!

http://www.harbeth.co.uk/usergroup/forum/the-science-of-audio/amplifier-matching-mismatching-and-clipping-a-curse/2486-how-much-amplifier-power-do-i-really-need

Here is the Pan Sonic "Laptevinmeri / Laptev Sea" track:

Even played at -30 on my system, this is frightening.

- Rich

That album has been on my playlist since I ran across it. I am playing it at "0" on mine right now due to the suggestion....nice little massage. FWIW I did put sufficient amplification on my subs, that probably helps my avr and mains out just a little bit. Alan is a bit wordy, couldn't get thru the video but playing this stuff on bookshelf speakers alone...I don't think so.

 

[PENG]

Hey Rich, since you mentioned ATI, take a look of the AT6005's S&V bench test data:

http://www.soundandvision.com/content/ati-at6005-amplifier-test-bench#19cd3DOtXFsf4yAx.97

So on an apple to apple (S&V to S&V) basis, the 88 lbs 300W/450W rated AT6002 or the 116 lbs AT6005 is just a touch more than 3 dB or 2X more powerful than the AVR-X4200W.

 

[RichB]

Hey Rich, since you mentioned ATI, take a look of the ATI6005's S&V bench test data:

http://www.soundandvision.com/content/ati-at6005-amplifier-test-bench#19cd3DOtXFsf4yAx.97

So on an apple to apple (S&V to S&V) basis, the 88 lbs 300W/450W rated AT6002 or the 116 lbs AT6005 is just a touch more than 3 dB or 2X more powerful than the AVR-X4200W.

Perhaps apples to watermelons

I do not think this is the end-all measurement for dynamic power and ability to drive difficult loads at low distortion levels. The ATI6000 is the first amp I have had that has absolutely no hum/buzz from the center or rear channels. Amps that buzzed in my system include: ATI3005, Sunfire 7400, Parasound A31, Parasound A51.

I also like amps with clip indicators, I haven't seen those avr's.

- Rich

 

[RichB]

That album has been on my playlist since I ran across it. I am playing it at "0" on mine right now due to the suggestion....nice little massage. FWIW I did put sufficient amplification on my subs, that probably helps my avr and mains out just a little bit. Alan is a bit wordy, couldn't get thru the video but playing this stuff on bookshelf speakers alone...I don't think so.

There is no way I would play that any higher than -10, full-range on the Salon2's. I'd like to keep the tweeters a while longer.

On popular music like Sarah McLachlan "I Love You" the peak indicators will start to illuminate at -6. I brought up and AVR and connected it to the Salon2's. There s no way this song can be driven to close to that level. It just starts sounding flat and upping the volume adds little but compression/distortion.

- Rich

 

[lovinthehd]

There is no way I would play that any higher than -10, full-range on the Salon2's. I'd like to keep the tweeters a while longer.

On popular music like Sarah McLachlan "I Love You" the peak indicators will start to illuminate at -6. I brought up and AVR and connected it to the Salon2's. There s no way this song can be driven to close to that level. It just starts sounding flat and upping the volume adds little but compression/distortion.

- Rich

Nice speakers. Tools for the job and all that. You run those without subs? My clipping indicators on the sub amps were being tickled...wish my avr had clipping indicators, tho it's fairly powerful and I do have about a 6dB sensitivity advantage over yours (if Harman was as accurate for my JBLs with the spec as yours), plus I'm crossing at 110.

OTOH reference volume level not something I do much, I rarely treat myself more than -20, some material -10, due to trying to conserve my poor old ears these days.

Now off to find the McLachlan tune in the library