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Would I benefit from an external amp?

post #1 of 30
Thread Starter 
Hey everyone,

Over the past couple of months, I've kind of changed my setup (new AVR, then a switch from 5.1 to 2.1, then new speakers), and had a few questions/was seeking some guidance.

It all started with my new receiver: I replaced my three-year old Pioneer Elite AVR with a Marantz SR5006 a few months ago. I noticed that it got slightly warm when driving my old speakers, B&W 685s (8 ohm, 88db sesnsitivity) but nothing significant. A few weeks ago I replaced the 685s with a pair of Monitor Audio Silver RX6s (6 ohm, 90db sensitivity), and have noticed that now the Marantz runs pretty hot all the time - after long music listening sessions or a long movie, to the point where If I'm close enough to it I can feel it throwing off heat. Much hotter than when it was driving the B&Ws. Some heat is normal, but to me it seems excessive. So I've been looking into maybe adding a relatively budget-friendly 2CH amplifier in the next couple of months to take the load off of the receiver.

So my question is twofold:

1) Should I be concerned with how hot my AVR is getting? Am I wrong in thinking it will impact the longevity of the receiver?
2) If I did add an external amp, do you think I'd be able to notice an uptick in sound quality? My current AVR sounds pretty damn good with these and is rated at 100w/ch with 2 channels driven (8 ohm rating though). I'd assume it would be an improvement over my AVRs internal amps but I read so much to the contrary of that here.

just as a reference, here are some amps I've been looking at:

-Emotiva XPA-200 (probably the best value, but I do find their stuff a bit ugly)
-ATI AT1202 (not super fond of the look, either, lol)
-Marantz PM8004
-Marantz MM7025
-Parasound 2125
-Parasound Halo A23

I mostly listen to music through my Apple TV and Audioengine D1 DAC, and occasionally through an Onkyo CD player.

anyway, thanks in advance for reading this, and I appreciate any and all advice!
post #2 of 30
The hotter electronics runs, the less reliable it becomes, but there's no way to predict when any specific unit will fail.

I assume you re-ran Audyssey to calibrate the receiver with the new speakers. The previous calibration won't sound as good. I also assume you've set the speakers to "Small" in the receiver, which is what enables bass management. You might consider raising the crossover frequency in the receiver to offload more of the low frequencies from the receiver's amps to the subwoofer's internal amp. That should help reduce the receiver's temperature.

If the receiver isn't being driven hard enough to cause distortion or clipping, then you shouldn't hear any difference in sound when you add quality external amps. (You'll have to re-run the Audyssey calibration, too, of course.) Offloading some of the power dissipation from the receiver to external amps would help keep its temperature down, of course.
post #3 of 30
You didn't mention whether your Marantz is in an open audio rack or partially or fully enclosed. If it is not in an open rack why not just add a fan to help cool it?
post #4 of 30
Thread Starter 
Thanks for the replies.

the speakers are set to small and crossover is set at 80Hz. I have actually just had Audyssey turned off since I got the new speakers. Would re-running Audyssey help? I left it off because I wanted to get a feel for how the speakers sounded by themselves, without any processing/EQing impacting their sound.

As far as placement, the receiver is on the bottom shelf of my TV stand. There's about 3" of clearance between the top of the receiver and the next shelf, and it's open on all other sides.
post #5 of 30
Different models of speakers have different frequency response curves. No speaker is linear, and some are quite a lot worse than others. Price is no indication of speaker accuracy (as you can see from the bench-tests included in many of the speaker reviews in Stereophile). frown.gif

Audyssey compensates for differences in speakers and in rooms and should be re-run whenever you change either. Recalibration might or might not reduce the total power requirements needed to drive your new speakers.

A speaker's woofer driver requires far more power than the midrange and tweeter drivers, so anything you can do to reduce the low frequencies going to the woofer will reduce the amount of power that the receiver will have to provide. That's why I suggested raising the crossover frequency to see if it helps.

3" really is too small for convection cooling. If you can't put the receiver elsewhere, I second the suggestion of providing an external fan to pull away the hot air.
post #6 of 30
Thread Starter 
I'll definitely try re-running audyssey and see how it sounds (didn't always like how it made my last pair sound with music) and look into cooling solutions. Thanks!
post #7 of 30
I keep reading in the AVR forum that AVRs rated for 8Ω should drive 6Ω no problems. This thread just shows even with Marantz it seems to be working much harder.

My integrated amp (150WPC) with metal casing and cooling side grilles runs cool driving 4Ω speakers with 3" space above.
post #8 of 30
The size of your room, its sonic characteristics, the efficiency of the speakers, and your preferred volume level all affect how much power is needed and thus how hot the receiver or amps will get. I drive 4 ohm speakers in my bedroom with a 50 W/ch Marantz receiver with no problems. I wouldn't even try to do that in my living room.
post #9 of 30
The Monitor Audio Silver RX6 impedance plot show it dips to nearly 4 ohms in the 150Hz to 300Hz area (above your crossover). I would normally have said this isn't a problem, but you mention that you're heating up more since the speaker change. In music, there's a lot of energy in that frequency range, and since its above the crossover frequency there's no off-loading it to the sub, at least not completely.

I'd suggest running Audyssey again. There's also a small response bump at 100Hz, which if Audyssey corrects would at least help.

No published specs on the Marantz, other than it's spec'ed into 8 ohms, which doesn't mean it can't drive 4 ohms, but it's not the heftyest amp every built. Might actually help to either upgrade it or use external amps in this case.

Can't emphasize proper venting enough! You can add a fan if you have to, there are some very quiet computer fans around these days, and you don't need much of a fan to make a decent improvement. Most computer fans have noise figures stated.

Here's the Monitor test data:
http://www.stereophile.com/content/monitor-audio-silver-rx6-loudspeaker-measurements
post #10 of 30
It is really really stupid to set the crossover at 80 Hz with those speakers; you should have them operating down to around 50 Hz (or lower)!! They are rated to go down to 38 Hz and you are treating them like mini-speakers. That is ridiculous.

Set the front speakers to full-range and set the subwoofer's filter so that it only operates up to 50 Hz.

Disable all of the "processing" and "equalization" and I'll bet the sound will be 100% better.

The MM7025 would be a big help to your overall system sound, however, and let your receiver do a better job overall. Its power supply is marginal for 5 channels.


Quote:
Originally Posted by fatuglyguy View Post

Thanks for the replies.
the speakers are set to small and crossover is set at 80Hz. I have actually just had Audyssey turned off since I got the new speakers. Would re-running Audyssey help? I left it off because I wanted to get a feel for how the speakers sounded by themselves, without any processing/EQing impacting their sound.
As far as placement, the receiver is on the bottom shelf of my TV stand. There's about 3" of clearance between the top of the receiver and the next shelf, and it's open on all other sides.
post #11 of 30
Quote:
Originally Posted by commsysman View Post

It is really really stupid to set the crossover at 80 Hz with those speakers; you should have them operating down to around 50 Hz (or lower)!! They are rated to go down to 38 Hz and you are treating them like mini-speakers. That is ridiculous.

Well, a lot of us do it and find it to be very effective for a number of reasons. No need to flame everyone who does. The fact that you still can't comprehend the reasons why after it has been explained to you multiple times in these forums, doesn't make it a "ridiculous" choice. Says more about you rolleyes.gif
post #12 of 30
Crossover filters are not brick walls. They let though a well defined amount of sound above and below their specified frequencies. The frequency setting of a subwoofer crossover normally should be set 1 octave above the "3db down" point of a speaker's frequency response curve in order for the resulting sound to be properly balanced. If you set it too low, there will be a noticeable dip in the sound level in the vicinity of the crossover frequency. The main speaker will be producing a reduced output, but the signal getting to the subwoofer won't be great enough to be offsetting it yet.

In other words, 80 Hz is only slightly high for speakers which have a response curve down 3 db at 38 Hz., since 1 octave above that would be 76 Hz.

Also, don't forget that manufacturers' frequency response curves are measured in anechoic chambers. Speakers sound quite different (have quite different frequency responses) when they're used in small rooms, like those in most homes. You actually have to measure the speakers' output in the location where you'll be using them in order to know their characteristics, which is what room equalization software like Audyssey and YPAO does.
post #13 of 30
Thread Starter 
So I'll just bump this thread to ask a question -- a friend recently purchased a XPA-200 and I had a listen to his speakers being driven by it, and they sounded pretty fantastic, very open, lots of headroom...and I can't help but get external amplification off of my brain rolleyes.gif

I'm wondering which would be a better choice: XPA-200 or a used A23?

I can get a discount on the Marantz PM8004 or the MM7025 though work, although I'm not sure how either one would rank among the emo or the parasound -- the MM7025 seems to be designed with powering a a second zone or rears in mind, and uses an EI transformer while the 8004 uses a toroid.

Thanks for any replies in advance!
post #14 of 30
Quote:
Originally Posted by fatuglyguy View Post

So I'll just bump this thread to ask a question -- a friend recently purchased a XPA-200 and I had a listen to his speakers being driven by it, and they sounded pretty fantastic, very open, lots of headroom...and I can't help but get external amplification off of my brain rolleyes.gif

I'm wondering which would be a better choice: XPA-200 or a used A23?

I can get a discount on the Marantz PM8004 or the MM7025 though work, although I'm not sure how either one would rank among the emo or the parasound -- the MM7025 seems to be designed with powering a a second zone or rears in mind, and uses an EI transformer while the 8004 uses a toroid.

Thanks for any replies in advance!

I'd go with Parasound, but plenty of other options also, depending on your budget.

Did you ever look into the Odyssey Audio amplifiers? Built like a tank and offer great sound quality, better than any AVR or budget amp.
post #15 of 30
Quote:
Originally Posted by fatuglyguy View Post

So I'll just bump this thread to ask a question -- a friend recently purchased a XPA-200 and I had a listen to his speakers being driven by it, and they sounded pretty fantastic, very open, lots of headroom...and I can't help but get external amplification off of my brain rolleyes.gif

I'm wondering which would be a better choice: XPA-200 or a used A23?

I can get a discount on the Marantz PM8004 or the MM7025 though work, although I'm not sure how either one would rank among the emo or the parasound -- the MM7025 seems to be designed with powering a a second zone or rears in mind, and uses an EI transformer while the 8004 uses a toroid.

Thanks for any replies in advance!

I'm sure your friend's system sounds great. But it is more likely that it sounds great because of the speakers and room acoustics than anything else.

In the real world I'd set up a level-matched DBT and prove to you that he just wasted a ton of money. There's a reason why people don't do amplifier DBTs at audio shows and in magazines with paid advertisting, and that is the dampening effect on sales that comes from a reality check.

Numbers don't lie. The XPA 200 is only 2 dB more powerful than your typical AVR. It takes 10 dB to create the impression of "twice as loud"

Even if you had to run both the AVR and the XPA 200 just below clipping, you'd be hard put to hear a difference with music. Chances are excellent that you never ever clip out your existing amp.
post #16 of 30
Quote:
Originally Posted by arnyk View Post

I'm sure your friend's system sounds great. But it is more likely that it sounds great because of the speakers and room acoustics than anything else.

In the real world I'd set up a level-matched DBT and prove to you that he just wasted a ton of money. There's a reason why people don't do amplifier DBTs at audio shows and in magazines with paid advertisting, and that is the dampening effect on sales that comes from a reality check.

Numbers don't lie. The XPA 200 is only 2 dB more powerful than your typical AVR. It takes 10 dB to create the impression of "twice as loud"

Even if you had to run both the AVR and the XPA 200 just below clipping, you'd be hard put to hear a difference with music. Chances are excellent that you never ever clip out your existing amp.

Arny do you ever take a break? Some people just want to try new things it is their money, if they can decide on their own if it was a waste of money. Odyssey has a trial period and I believe some other manufacturers might to? I know you think your opinion trumps all, but come on now!
Edited by Todd68 - 1/27/13 at 5:10am
post #17 of 30
You don't seem to realize that anything he says IS a fact! If he says it, it has to be true...rofl. Let's show some respect.

Quote:
Originally Posted by Todd68 View Post

Arny do you ever take a break? Some people just want to try new things it is their money, if they can decide on their own if it was a waste of money. Odyssey has a trial period and I believe some other manufacturers might to? I know you think your opinion trumps all, but come on now!
post #18 of 30
Quote:
Originally Posted by Todd68 View Post

Quote:
Originally Posted by arnyk View Post

I'm sure your friend's system sounds great. But it is more likely that it sounds great because of the speakers and room acoustics than anything else.

In the real world I'd set up a level-matched DBT and prove to you that he just wasted a ton of money. There's a reason why people don't do amplifier DBTs at audio shows and in magazines with paid advertisting, and that is the dampening effect on sales that comes from a reality check.

Numbers don't lie. The XPA 200 is only 2 dB more powerful than your typical AVR. It takes 10 dB to create the impression of "twice as loud"

Even if you had to run both the AVR and the XPA 200 just below clipping, you'd be hard put to hear a difference with music. Chances are excellent that you never ever clip out your existing amp.

Arny do you ever take a break?

If you haven't noticed I almost never start threads or take threads off topic. That means that my posts are responses to other people's posts. They take a break, I take a break.
Quote:
Some people just want to try new things it is their money,

That's fine. I guess you don't notice the absence of Arny's Brown Shirts who fly to cities across the world and hold people at gunpoint so that they don't spend their money in politically incorrect ways. ;-)
Quote:
if they can decide on their own if it was a waste of money. Odyssey has a trial period and I believe some other manufacturers might to? I know you think your opinion trumps all, but come on now!

Like I said if you hadn't taken it upon yourself to bait me like this, I probably would have passed this thread by.

Oh, I get it, in your world there is one set of rules for you and a different set of far more restrictive rules for me! ;-)
post #19 of 30
Quote:
I guess you don't notice the absence of Arny's Brown Shirts who fly to cities across the world and hold people at gunpoint so that they don't spend their money in politically incorrect ways.
You know what we need, Arny? Objectivist drones!
post #20 of 30
Quote:
Originally Posted by Todd68 View Post

Arny do you ever take a break?..!
You mean he shouldn't pass on important information as he sees fit?
post #21 of 30
I think an external amp might be helpful if you were running 5.1 and your front speakers were more demanding. But, with 2.1 it would seem the 5006 should be plenty provided you re-run Audyssey and use an 80 Hz crossover as already suggested.
Quote:
Quote:
I guess you don't notice the absence of Arny's Brown Shirts who fly to cities across the world and hold people at gunpoint so that they don't spend their money in politically incorrect ways.
You know what we need, Arny? Objectivist drones!

I thought you two were the Objectivist drones. You could write your own treatise and call it Fountain of Audio Head. Just kidding and sorry I couldn't resist.
post #22 of 30
Thread Starter 
Didn't mean to start anything, lol. Technically I'm running 3.1 now, I have the RX center. I re-ran Audyssey and it sounds good....but I do wonder if I could eke out any more performance when listening to music, I mean I think I know the answer, but I can't help but wonder smile.gif
post #23 of 30
Quote:
Originally Posted by CharlesJ View Post

Quote:
Originally Posted by Todd68 View Post

Arny do you ever take a break?..!
You mean he shouldn't pass on important information as he sees fit?

It is really very interesting to see who wants to end other people's free speech.
post #24 of 30
Quote:
Originally Posted by fatuglyguy View Post

Didn't mean to start anything, lol. Technically I'm running 3.1 now, I have the RX center. I re-ran Audyssey and it sounds good....but I do wonder if I could eke out any more performance when listening to music, I mean I think I know the answer, but I can't help but wonder smile.gif

I'd like to make it possible for people to do more than wonder. But, I don't see sighted evaluations or equipment-buying expeditions to be a reasonable way to do it.

It is possible to figure out whether or not you amps are clipping or creating excess distortion, but it takes a software setup along the lines that people are setting up to tune their rooms and speakers with to do it.
post #25 of 30
Quote:
Originally Posted by Todd68 View Post

Arny do you ever take a break? Some people just want to try new things it is their money, if they can decide on their own if it was a waste of money. Odyssey has a trial period and I believe some other manufacturers might to? I know you think your opinion trumps all, but come on now!

With respect to you Todd and apologies to the OP for straying from the thread, I strongly disagree. ..Aside from the occasional snidery (yes, I just invented that word) which makes me wince and for which I've also griped at Arny, I very much like his persistence in advocating for objectivity. ..This hobby needs more of this. There is no shortage of people on this site willing to give their wine-tasters impression of how this amp sounds bloated and this CD player sounds shrill, etc.. yet very few bringing any science into the discussion. Arnyk does this. ..I'll bet many a newbie has come here, read his posts, saved a ton of $ as a consequence and ended up happier with their system. People come here looking for advice and Arnyk gives his.

Arnyk: It would be very interesting if you shared some your objectivist's viewpoint on audioasylum.com as well; particularly the amp/preamp section.. At least here at AVS there is some objectivity, there is absolutely none at AA and your posts would undoubtedly lead to some very interesting discussions.
Edited by syd123 - 1/28/13 at 3:44am
post #26 of 30
Thread Starter 
So let me recap this (and I appreciate the advice from all sides, really):

Objectively, if my AVR is performing within spec and not clipping, then I will not/should not be able to hear a difference or improvement in dynamics, etc. when powering my speakers with an external power amplifier. Any difference I would notice would result from my own expectation that I'd hear a difference?

Ugh.
post #27 of 30
Quote:
Originally Posted by syd123 View Post

With respect to you Todd and apologies to the OP for straying from the thread, I strongly disagree. ..Aside from the occasional snidery (yes, I just invented that word) which makes me wince and for which I've also griped at Arny, I very much like his persistence in advocating for objectivity. ..This hobby needs more of this. There is no shortage of people on this site willing to give their wine-tasters impression of how this amp sounds bloated and this CD player sounds shrill, etc.. yet very few bringing any science into the discussion. Arnyk does this. ..I'll bet many a newbie has come here, read his posts, saved a ton of $ as a consequence and ended up happier with their system. People come here looking for advice and Arnyk gives his.

Arnyk: It would be very interesting if you shared some your objectivist's viewpoint on audioasylum.com as well; particularly the amp/preamp section.. At least here at AVS there is some objectivity, there is absolutely none at AA and your posts would undoubtedly lead to some very interesting discussions.
fwiw, well said i totally agree he gives that other dimension even if you disagree with him he still can back his knowledge up and make you think . i've learned a few things myself over the years as this is the av science forums
Edited by smasher50 - 1/28/13 at 4:23am
post #28 of 30
Quote:
Originally Posted by fatuglyguy View Post

So let me recap this (and I appreciate the advice from all sides, really):

Objectively, if my AVR is performing within spec and not clipping, then I will not/should not be able to hear a difference or improvement in dynamics, etc. when powering my speakers with an external power amplifier. Any difference I would notice would result from my own expectation that I'd hear a difference?
.

Yes.

The objective difference that it actually takes to reliably change our perceptions of improvements in dynamics, etc. is well known. We have production tools that allow technical people to alter dynamics perceptibly. They have been around for decades. They have calibrated knobs on them and it is generally known how far to turn the knobs to actually alter the sound of the dynamics in music.

We also know about the tendencies of power amplifiers to make similar changes to music. With modern amplifiers, and the era of modern amplifiers goes back into the middle 1970s, power amplifiers only make itsy-bitsy changes to music in comparison. Changes we can measure but cannot possibly hear, and not by a little.

The exception is when a power amplifier clips. In times past and I would say through the 1970s but not very far into the 1980s, there were problems with SS power amplifiers that clipped prematurely with certain tough speaker loads. As a rule both the amplifiers and the speakers have improved greatly since then. Speaker manufacturers discovered that it is pretty deadly for their bottom line to try to sell speakers that only a few amplifiers can drive, and amplifier manufacturers discovered that building amplifiers that only worked well with a few speakers was equally bad for their bottom line. Technology did its part, and the critical parts that related to this now-solved problem improved greatly during the latter 1970s and early 1980s.

The other thing that happened in the 1970s and early 1980s is that we learned a great deal about how to do listening tests involving audio gear. The expectation that different pieces of audio gear sounded different was based on how real world audio gear worked from day 1 (late 1920s) through the mid-1980s at the latest. The problem dramatically improved with the second and third generation of SS audio gear, both amps and preamps. Digital audio did its part by eliminating the need for analog tape and LPs, which were always problematical and had inherent problems that have not been adequately solved through this days.

So,what was a reasonable expectation decades ago became an unreasonable expectation today. However, the brain is the most powerful organ in the body and its effects on perception are not to be trifled with. Group memory and culture are pervasive and nearly all-encompassing. In the 1970s we found that people would definitely perceive differences when none could possibly exist. I can make the same amplifier sound to you like it is two different amplifiers by simply convincing you that is the case and making no other changes.

As I have said in other posts there are technical differences that are so strong that they can be reliably perceived even when there are many conflicting influences. For example a small AM radio sounds different from a great HT system with total disregard for differences in the testing environment. However when comparing good modern audio gear, differences on that scale have become very elusive and you really need to set up your test very carefully or else perceived differences due to your test setup will overwhelm the tiny or non-existent audible differences that are actually due to differences in SQ. Nobody does these things in audio stores or at audio shows, and only a very few people even takes this kind of care when they compare gear at home or in a laboratory environment.

There are standards organizations publications that list out and describe in detail what it takes to do a good comparison test relating to sound quality. Perhaps the best known of these is ITU Recommendation BS 1116-1, which can be purchased online for a nominal fee. http://www.itu.int/rec/R-REC-BS.1116-1-199710-I/e

And here it appears to be for free:

http://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.1116-1-199710-I!!PDF-E.pdf

I grieve over the fact that doing the classic audiophile listening test has become this complex and demanding to do right, but it is a small price to pay for all of the progress in SQ that I have personally seen and heard since the 1950s.
post #29 of 30
Guys, I was just picking on Arny a bit, no disrespect intended. He is dedicated and smart. But part of the fun for some in this hobby is trying different "better" gear.

I havn't changed amps for 10 years myself, but I did sample a few very good preamps and power amps before I settled with what I now use. They all sounded different to me, especially the tube preamplifiers. And phono stage amplifiers can sound quite different too.

I totally agree speakers and room are most important to the overall sound, but I don't like to discourage folks from trying different amps etc. if they would enjoy the experiences, they then can form their own opinion that way.

People in this hobby have all sorts of opinions that should be respected. I have been called an audiophool, snake oil believer, ignorant and gullable already. I am big boy though, I can take it!

Happy Listening!
post #30 of 30
Quote:
Originally Posted by Todd68 View Post

I totally agree speakers and room are most important to the overall sound, but I don't like to discourage folks from trying different amps etc. if they would enjoy the experiences, they then can form their own opinion that way.
I don't see much of discouragement on that, if at all. I do see many questions on their method of comparison. By the way, there are many a / v forums out there. People choose the one that suits their taste and go with it but that won't be possible if all the forums were the same.
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