When to Add External Amplification to an A/V Receiver

[tomd51]

I have a Yamaha RX-A2030 - 140 wpc... But at 9 channels driven, probably closer to 70? I'm running NHT Absolute Towers as my Mains. I have 3 Emotiva XPA-100 (250 wpc and 32db Gain) that I was going to hook up to my Fronts and Center. Should I? I want things to sound as good as they can - but, I have heard about AVR's Clipping due to their preout voltage, and the Yamaha is rated at 1.0V ... I've heard this might be understated. I really want to run the Emotiva's, but don't want to hurt my AVR. Any thoughts or advice? Thank you!

I've been using my RX-A2000 with an XPA-2 and UPA-7 for a couple of years now in my 3000+ cu. ft. theater, which I do enjoy listening to music from time to time fairly loud and I've had no issues whatsoever, besides the stern look from the wife from time to time... -TD

 

[cpp]

It's a huge deal that is often overlooked. And the remedy could be a lot cheaper, simpler and faster than adding an external amp.

So for the guy throwing that house party and leaving his AVR on for 6+ hours playing 90+ dB volume, grab a small cooling fan and cool that AVR!

Sometimes natural ventilation isn't enough; sometimes the AVR just needs intervention.

So true Obi-Wan. I have ordered a paired fan kit CG CabCool802 Dual 80mm Fan Cooling kit for Cabinet - Home Theaters which should take care of the problem...

 

[AcuDefTechGuy]

So true Obi-Wan. I have ordered a paired fan kit CG CabCool802 Dual 80mm Fan Cooling kit for Cabinet - Home Theaters which should take care of the problem...

Good for you. Of course I just use a cheap 6" fan I got for free somewhere. Man, I'm cheap.

 

[cpp]

Good for you. Of course I just use a cheap 6" fan I got for free somewhere. Man, I'm cheap.

NO remember, you are saving for a new # 1 a new house or #2 an addition to your existing home so YOU can have a dedicated audio room. that's the plan remember

I can remember it now, "Read My Lips, NO New Speakers or AMPS "

 

[AcuDefTechGuy]

NO remember, you are saving for a new # 1 a new house or #2 an addition to your existing home so YOU can have a dedicated audio room. that's the plan remember

I can remember it now, "Read My Lips, NO New Speakers or AMPS "

That's true. Dream house and dream car take precedence over HT needs right now. Can't even squeeze a dime for HT. Definitely no more ATI amps until those wishes are fulfilled.

 

[herbu]

Man, I'm cheap.

I already have an ATI AT3005, AT3002, AT2004, and AT6012.

 

[Goliath]

In my opinion, amplifier power is one of the biggest red herrings in all of audio. It just isn't a big issue in most typical conditions, at reasonable seated distances and listening levels.

Most typical people probably don't even exceed 50 watts in extreme conditions with typical speakers (87-90 dB 1W/1M) at reasonable distances (~ 3 meters). What is a dedicated power amp going to offer in such conditions?

The fabled ACD test is not something that people need to worry about. People don't listen to pure tones that have a very low crest factor, nor do they listen to resistive loads, nor are all channels required simultaneously and at high power - just two of these variables probably require many times more power than you'll likely need when listening to music or drama.

Movies don't require simultaneous power into all channels either, so that's another huge weight lifted off receivers which are stress tested to the max on the test bench. I just think the subject of amplifier power is blown way out of proportion most of the time.

 

[AcuDefTechGuy]

Well, a guy can still be frugal, can't he?

I have a McDonald's coupon for buy one large sandwich (like double quarter pounder + cheese) and get one free. Saved me 5 bucks right there.

 

[gene]

In my opinion, amplifier power is one of the biggest red herrings in all of audio. It just isn't a big issue in most typical conditions, at reasonable seated distances and listening levels.

Most typical people probably don't even exceed 50 watts in extreme conditions with typical speakers (87-90 dB 1W/1M) at reasonable distances (~ 3 meters). What is a dedicated power amp going to offer in such conditions?

The fabled ACD test is not something that people need to worry about. People don't listen to pure tones that have a very low crest factor, nor do they listen to resistive loads, nor are all channels required simultaneously and at high power - just two of these variables probably require many times more power than you'll likely need when listening to music or drama.

Movies don't require simultaneous power into all channels either, so that's another huge weight lifted off receivers which are stress tested to the max on the test bench. I just think the subject of amplifier power is blown way out of proportion most of the time.

Very good points but separate amps tend to drive demanding speaker loads a lot better than budget or even midpriced AV Receivers. Even at lowish power levels we have found audible differences. It really depends on speaker type, room acoustics and source material.

 

[Goliath]

Very good points but separate amps tend to drive demanding speaker loads a lot better than budget or even midpriced AV Receivers. Even at lowish power levels we have found audible differences. It really depends on speaker type, room acoustics and source material.

If the voltage and the load impedance do not require the additional power that a larger amplifier can supply then adding a dedicated power amp cannot improve the sound. The load simply will not 'see' it. The amp can't supply more power than the load demands at a given voltage. Ohms Law forbids it.

At a low voltage, there would be no need for a dedicated power amp over a receiver. Ditto for demanding loads, but even if the load was demanding, if the volume was at a low level, the current draw would be minimal and the applied voltage would be minimal = ?? = so how would a power amp improve the sound in such conditions?

 

[AcuDefTechGuy]

In my opinion, amplifier power is one of the biggest red herrings in all of audio. It just isn't a big issue in most typical conditions, at reasonable seated distances and listening levels.

I think that's the key right there - most TYPICAL conditions.

There are always ATYPICAL conditions.

 

[Goliath]

I think that's the key right there - most TYPICAL conditions.

There are always ATYPICAL conditions.

Fair enough. It's just that many people seem to think that a power amp can improve the sound regardless of the conditions. If you listen at very high SPL (over 100 dB) sit far away from the speakers in a large room, with insensitive speakers that have a complex impedance curve, then sure, your requirements for power would differ from the next person.

How many people listen at over 100 dB, seated far away from their speakers, in large rooms, with insensitive speakers that have weird impedance curves? Probably not THAT many, , but I certainly could be wrong.

 

[gene]

If the voltage and the load impedance do not require the additional power that a larger amplifier can supply then adding a dedicated power amp cannot improve the sound. The load simply will not 'see' it. The amp can't supply more power than the load demands at a given voltage. Ohms Law forbids it.

At a low voltage, there would be no need for a dedicated power amp over a receiver. Ditto for demanding loads, but even if the load was demanding, if the volume was at a low level, the current draw would be minimal and the applied voltage would be minimal = ?? = so how would a power amp improve the sound in such conditions?

That is a very closed minded opinion and a narrow analysis of a complex steady state problem using static analysis. As someone who not only reviews amps and speakers for a living, but has also designed amps and holds an EE in analog engineering, I would never make a statement like that nor do I agree with it.

 

[herbu]

That is a... narrow analysis.

Therein lies the rub. Goliath, I think your analysis makes sense for the majority of users, the majority of time. I have our system on low volume music or TV most of the time. But once or twice a week, we'll watch a movie where I'll have the floor shaking and the cats hiding under the bed. I subscribe to the belief that my most demanding usage should ideally be well within the limits of my equipment. So you're right that in my "typical" conditions, a separate amp is not necessary. But it is the atypical conditions that I enjoy the most, thus tailor my system to handle.

 

[Goliath]

That is a very closed minded opinion and a narrow analysis of a complex steady state problem using static analysis. As someone who not only reviews amps and speakers for a living, but has also designed amps and holds an EE in analog engineering, I would never make a statement like that nor do I agree with it.

What exactly do you disagree with? The physical laws of the universe???

Here are a few statements :

"If the voltage and the load impedance do not require the additional power that a larger amplifier can supply then adding a dedicated power amp cannot improve the sound."

What do you disagree with?

The load simply will not 'see' it. The amp can't supply more power than the load demands at a given voltage. Ohms Law forbids it.

What do you disagree with? Can the load 'see' unlimited power that an amplifier can potentially supply? All power is potential unless the load requires it. Do you disagree?

At a low voltage, there would be no need for a dedicated power amp over a receiver

What do you disagree with here, exactly? Why would a speaker need a power amp at a low voltage?

even if the load was demanding, if the volume was at a low level, the current draw would be minimal and the applied voltage would be minimal = ?? = so how would a power amp improve the sound in such conditions?

What do you disagree with? Seems like perfectly legible English. Is the above technically inaccurate and if so, can you explain?

Some of your comments don't appear to be based on anything real. You made some assumptions in your earlier post which could be explained by the placebo effect or just plain expectation bias. If a power amp could improve the sound of a speaker at any level, then a larger power amp could improve on the sound of any speaker at any level, and a larger amp still could continue to improve the sound of said speaker, etc etc etc?

I think we both know that doesn't make any sense. Speakers can't tell whether a larger amp has been connected to its terminals, can they?

Is that what you are suggesting? If not, what exactly are you suggesting?

 

[Goliath]

Therein lies the rub. Goliath, I think your analysis makes sense for the majority of users, the majority of time. I have our system on low volume music or TV most of the time. But once or twice a week, we'll watch a movie where I'll have the floor shaking and the cats hiding under the bed. I subscribe to the belief that my most demanding usage should ideally be well within the limits of my equipment. So you're right that in my "typical" conditions, a separate amp is not necessary. But it is the atypical conditions that I enjoy the most, thus tailor my system to handle.

Sure, and your atypical condition requires a power amp over your receiver, correct? Based on what reliable analysis?

 

[Goliath]

Very good points but separate amps tend to drive demanding speaker loads a lot better than budget or even midpriced AV Receivers. Even at lowish power levels we have found audible differences. It really depends on speaker type, room acoustics and source material.

As far as I'm concerned the above is mystery meat. If you are basing your comments above on sighted evaluations then we've already hit a concrete wall. There is nothing more to discuss.

 

[Nestor]

I added an XPA-3 to take over the LCR from my RX-A3000 because I could send the AVR into overload protection during reference levels under repeatable conditions.

I had no expectations for "improved sound quality" other than "making sure I had sound during transients".

The article provides a reasonable rule of thumb for deciding on whether you might consider adding external amplification. If I were to nitpick, I'd say the chart could be more detailed about "hard to drive" speaker loads.

I don't really see anyone here making outlandishly subjective claims typically made at Absolute Sound, so I'm not sure what Goliath's beef is.

 

[gene]

What exactly do you disagree with? The physical laws of the universe???

Here are a few statements :

"If the voltage and the load impedance do not require the additional power that a larger amplifier can supply then adding a dedicated power amp cannot improve the sound."

What do you disagree with?

The load simply will not 'see' it. The amp can't supply more power than the load demands at a given voltage. Ohms Law forbids it.

What do you disagree with? Can the load 'see' unlimited power that an amplifier can potentially supply? All power is potential unless the load requires it. Do you disagree?

At a low voltage, there would be no need for a dedicated power amp over a receiver

What do you disagree with here, exactly? Why would a speaker need a power amp at a low voltage?

even if the load was demanding, if the volume was at a low level, the current draw would be minimal and the applied voltage would be minimal = ?? = so how would a power amp improve the sound in such conditions?

What do you disagree with? Seems like perfectly legible English. Is the above technically inaccurate and if so, can you explain?

Some of your comments don't appear to be based on anything real. You made some assumptions in your earlier post which could be explained by the placebo effect or just plain expectation bias. If a power amp could improve the sound of a speaker at any level, then a larger power amp could improve on the sound of any speaker at any level, and a larger amp still could continue to improve the sound of said speaker, etc etc etc?

I think we both know that doesn't make any sense. Speakers can't tell whether a larger amp has been connected to its terminals, can they?

Is that what you are suggesting? If not, what exactly are you suggesting?

You are assuming a speaker is a simple resistor. It is NOT. You are assuming an audio signal is a simple steady state tone. It is NOT. There are many factors that affect sound quality. I am not in the camp that ALL amps sound the same if not driven beyond their linearity. I've heard differences in blind tests between amps at low listening levels to know better than to make this type of generalization. You make absolute statements without actually being able to measure or analyze any particular cases. If an amp was a perfect voltage source (no noise or distortion, zero output impedance, unlimited current) and a speaker was a linear device (purely resistive and not changing based on driven level or frequency) then and ONLY then would I agree with most of your statements.

If you truly believe that all amps sound the same when not over driven than more power to you. It certainly saves you a lot of money in the long run. I really don't care to convince you otherwise as I stand behind my testing, measurements and analysis to formulate my own opinions.

 

[gene]

As far as I'm concerned the above is mystery meat. If you are basing your comments above on sighted evaluations then we've already hit a concrete wall. There is nothing more to discuss.

How the F*CK does it matter if an amp test is sighted or blind? If someone else is doing the switching, and its level matched, there is no way for the listener to know which amp is playing. It blows my mind how one can over generalize with little or no real world experience or analysis rather than to keep an open mind and understand the complexity of an audio system.

This is why the whole DBT thing often frustrates me. It allows people to dumb down the whole audio experience into generalizations like:

• MP3 is similarly good as CD
• All amps sound similarly good
• $200 speakers sound similarly good to $2k speakers
• etc

OK I'm off my soap box now. Time to do some "sighted" listening tests