EMOTIVA Amps - Power Rating Discussion - Page 4 - AVS Forum
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post #91 of 421 Old 02-17-2011, 02:36 PM
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post #92 of 421 Old 02-17-2011, 02:43 PM
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post #93 of 421 Old 02-17-2011, 02:52 PM
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Quote:
Originally Posted by ss9001 View Post

That's about where I'm at. I have no skin in the game, don't own their gear, but have looked at their offerings because they are "cheap" and I admit that's tempting.

I'll say it again, if I were in the market for a monoblock or stereo amp, their XPA's do look fairly spec'd and are great values. The others....

I have owned Emotiva amps (XPA-5, LPA-5), I have also owned their speakers and the LMC-1... I do not own any of them any more.

All your points are great but the XPA1 and XPA-2s are not really great values at all, I think their XPA-1 and XPA-2 are a waste of $$$.

1. Running that much power into main speakers is silly, the amount of compression/distortion in most cases is too high. People that think they need all that power seldom have any idea about their speaker designs and what is really happening at those high voltage levels.


2. If we want that much power then we go with proven pro audio amps. The XPA-1 and XPA-2 are overpriced compared to valid pro options. I guess people are just paying for comercial looks.

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post #94 of 421 Old 02-17-2011, 02:56 PM
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Penn, if you get time, I found an article from Stereophile written by someone who seemed to know what they were talking about on speaker power compression

He did not actually find much going on, and he used material lacking dynamic range.

http://www.stereophile.com/reference/1106hot/index.html

Back when I first compare pro amps, I found the XPA-3 to be a pretty good deal, compared to buying two pro amps. In this case, I have to disagree a bit with you.

However, if I could do it all again, I would look at buying 3 class D pro amps to simplify moving them around. Problem is, I have noise from my Crown, and hum because it's grounded. Not having those issues with the XPA-3, I would want a pro amp that had the same lack of issues. The hum can probably be solved with an isolation transformer for my cable line. The noise is another issue - I don't really care to hear noise 12" from my speaker drivers to be honest...

"But this one goes up to 11"
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post #95 of 421 Old 02-17-2011, 03:16 PM
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With all respect to Audioholics and the excellent job I think they do, I feel there is some value to some test driving all channels.

Perhaps it needs to be something like the dynamic test Audioholics is now using rather than a power sweep.

I don't see a lot of good options out there for basic evaluation of power in amps/receivers.

Two channel, 20-20 khz test - tells us something, but does not really show how budget receivers limit power, making them seem better than they are?

All channels driven, 1khz sweep - As Audioholics argues, probably not indicative of real world load. But does it tell us something about a receiver/amps power supply and/or how quickly the limiter circuits kick in?

Burst test - I don't know enough to evalulate how closely this mimics real world content, specifically movies

Weight - Some indication of power supply capability, but has various issues such as different cabinet sizes and construction, and weight from other factors

Power consumption - Even if the manual does list power consumption, I don't think this is indicative of peak capability

I guess I prefer what Audioholics does now. Give the 2 channel measurement, the sweep and the burst, and you then have a lot of numbers to look at which I think gives a fair idea of what an amp/receiver can do?

Ultimately, and in my own opinion, power measurements will never tell the whole story. Some rough guidelines (my own opinion of course) -

* Avoid those sub $400 receivers. For example, look at how Yamaha's 667 is a nice step up from the 567, and ask if it's worth the better power supply.

* Buy whatever receiver meets your needs, but consider something with pre outs. If after spending time with your system, you conclude you are too demanding for the receiver, add some external amps - there are affordable options out there.

* Don't buy $1000+ receivers for power only. You are starting to reach the limits of receiver power in that price range, and are heavily paying for top end VP, network features and such. May as well reconsider options that involve a cheaper receiver that meets your needs then add external amps.

* Shooting for reference level is going to cost you. You need very good subwoofer(s,) substantial power, and speakers that can get it done. If you are pragmatic about it, you can get within 6 dB or so for less money. You are pushing the laws of diminshing returns as you push towards reference level SPL.

Just my own thoughts...

"But this one goes up to 11"
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post #96 of 421 Old 02-17-2011, 04:29 PM - Thread Starter
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Quote:
Originally Posted by penngray View Post

You didnt just call me "fandom", did you?? That would be extremely funny considering my long time position on Emotiva equipment

My point really is that power differential is almost meaningless in real terms. I never though Emotiva had a rep for any 'REAL' specs. I thought they simply are a low cost online audio equipment source. Nothing special at all.

PennGray -- just got off the phone with Richard at ParaSound in the City, and he said that EMO makes some very nice amps for the cost indeed. So I asked him why should I pay over 300% more for his 5250v2, which only sources 25% more power than the EMO if we believe in the specs. Guess what he told me to do?
He said buy the EMO, and most likely you will be happy. He has tested the EMO XPA-5 and stated that it performs to their specs. Parasound has their own Mkt. like recording/film and Dolby industries. Very interesting ... for sure.
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post #97 of 421 Old 02-17-2011, 04:42 PM - Thread Starter
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Originally Posted by JHAz View Post

don't know, but if we were talking about Bryston, which is even more expensive, you'd be seeing a huge S/N ratio, amazing distortion performance, huge power. Query whether you could hear any of these differences, but Bryston does seem to make astoundingly clean amps. I used to have a little one, but could not at present bring myself to purchase even a used multichannel, because I don't sense that I'm pushing my midlevel Denon receiver hard enough for cracks to appear in its performance . . . and I can't buy tech for tech's sake at present.

JHAz -- that is part of what started this discussion of EMO Power Ratings, etc. I pushed my Denon AVR-3311CI driving FL/FR/C/SL/SR Klipsch's w/sensitivities at 98db in Multi Ch Stereo Mode, and the Denon PROTECTED itself and shut down at +12db (Never made it to +18db) -- now was it loud yes, and clipping YES... totally distorted and thermal runaway on the Denon, and it SHUT DOWN. BTW - I love the front end of the Denon for Pre/Pro, and it has a lot of nice features, but not for any degree of power in a 5.1 or 7.1 as is the case here.

So, that is what this thread is about POWER discussions on the Emotiva Amps.
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post #98 of 421 Old 02-17-2011, 04:51 PM
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Any plans to test the XPA-5? For the record, I am an Audioholics user, love the reviews your group does.

On your comment about the receivers' cost, I don't need to remind you that you can get an SC-37 for less than $2K and if you bought a UPA7 amp you'd still have to add the cost of a decent prepro which makes the comparison in favor of the receiver or at best equal, doesn't it?

No need to test an XPA-5 when I already tested an XPA-2 and they are so similar. With Emotiva changing and upgrading amps so frequently, I will wait for their next model lineup to do another review.

Quote:
And I'm afraid I'm in the school of thought that has high regard for the ACD test though it looks like we are a dying breed!

That is why I still do ACD testing despite its not a typical real world usage scenario.

Quote:
With all respect to Audioholics and the excellent job I think they do, I feel there is some value to some test driving all channels.

Perhaps it needs to be something like the dynamic test Audioholics is now using rather than a power sweep.

We do both

The CEA Burst testing I do is very similar to how THX does their power testing and is much closer to music program material than a continuous sinewave sweep test.

Quote:
* Avoid those sub $400 receivers. For example, look at how Yamaha's 667 is a nice step up from the 567, and ask if it's worth the better power supply.

Yes try to avoid receivers that don't have a discrete amp section. I was glad Yamaha replaced the 665 with the 667 after I hammered them on it here:

Trading Amplifier Quality for Features

Best Regards;

Gene DellaSala (GDS)
President, Audioholics.com
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post #99 of 421 Old 02-17-2011, 04:58 PM - Thread Starter
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Originally Posted by DonH50 View Post

Wow, what a hoot!

My take on Emotiva is what I said: great performance for the price (good value). I have not compared them recently with any high-end equipment (or very little, and not in my system so I can't really comment). There are plenty of reviews favorable to them at their price point, and frankly I wanted to put my money into other things than $20k worth of amps. Like room treatment, and college tuition for my boys...

I cannot, and as far as I know, do not claim they will match said monoblocks. Don't know they won't, to me, but I have not listened recently. I could rig up a test system to check their power, but it's not worth it to me. I have work to do and a concert to prepare for in my free time (anybody in the Colorado Springs area? -- www.pikespeakphil.org ).

I have Magnepan MG-IIIa's, a relatively benign load but 4-ohm and fairly inefficient so they suck some power. Center CC3, surrounds and rears MC-1's. An XPA-2 drives the L/R and XPA-5 the rest. Maybe it is a piece of junk, but it sounds OK to me. My past experience leads me to belive that differences among SS amps is subtle at best once you exceed a fairly low threshold. (Threshold, another great old amp...)

My previous setup was probably 15 years back, before the system went into storage while Life took over. Then, I used a modified ARC SP3a-1 preamp, and biamped the MG-IIIa's with an ARC D-79 on top and Counterpoint SA-220 on the bottom. At that time (say mid-80's) I worked in the business and a number of amps, including Bryston, Krell, CJ, Levinson, etc. all passed through the system. I loved my tubes, whilst knowing they were not the cleanest, quietest, nor provided the best bass. I just liked the sound, colored as it was. When I set up my system again I went into deep depression when I realized the class of equipment I had before was far beyond my means, and I didn't really have the time and funds to bring all my tubes back to life. The Emotivas filled the gap nicely enough for me.

I have always found specsmanship a bit misleading and marketing-led so have never been particularly upset by claims (some are pretty funny, but that's another thread). I use the spec sheet as a rough guide, then read reviews and test results. The biggest spec-shock I have had in the past couple of years was finding out just how little power by previous Sony AVR actually put out...

As for credentials, in addition to decades in the biz (usually install and repair work, plus a lot of live sound and some studio mastering) I have a few degrees in electrical engineering that I have put to good use in the world of high-speed (GHz+) analog IC design. Gives me no more cred than anyone else since you probably can't prove it online.

Don't think I can contribute any more (not sure I actually did any at all) to this thread, but there's my take on it.

FWIWFM, my 0.00001 cents, YMMV, blah blah blah - Don

DON -- That was a Very Nice writeup, and your few degrees in EE, must put you at a .PHD level then without the Period , as my degrees are a few less, but some for sure and hats off to your excellent writeup here.

So as Don stated the EMO's are working fine there, like many others have stated.

What's interesting his Sony AVR also gave him Spec-Shock, like the Denon AVR of mine did. Same thing, different AVR!
The AVR's today are more of a Front End than a Real Amp, and we all know that, but it fits the Mktg. bill and home Mkt. place fine, w/o using a forklift to load it onto a shelf in the ave. home environment.
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post #100 of 421 Old 02-17-2011, 04:59 PM
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Quote:
Originally Posted by penngray View Post

1. Running that much power into main speakers is silly, the amount of compression/distortion in most cases is too high.

Even for electrostats and inefficient planars like Magnepan?

The vast majority of Maggie owners would disagree with you on this.

My own experience with their middle speaker in their line, the 1.6QR, was that while my 140 watt 8 ohm receiver drove them, going to an amp with 300 watts at 8 ohms allowed transients like the action on piano keys, percussive drum thwacks, all came through more clearly with the higher power driving the speaker. It's possible that the receiver was power supply limited at 4 ohms but I was only listening to 2 Ch and bench tests showed it was capable of >200 watts 4 ohms, 4 channels driven - but like this discussion, who knows what the test conditions were.

In every listening comparison I did except 1 Peter Gabriel recording where I couldn't tell any difference, the speaker responded better with the higher powered amp: the massed choral part of Beethoven's 9th was less congested, percussion attacks in Dire Straits Brothers in Arms, piano in various recordings both classical & jazz, all sounded better with the 300/600 watt amp at same volume settings. I didn't have a db SPL meter then, but I left the volume control on the receiver the same. If it wasn't exact, it was darn close to being same.

I agree with you that the vast majority of conventional dynamic speakers even if 4 ohms don't need nearly that much power, but planars & electrostats are a different story. Stats need hi-current, and planars benefit from hi power to drive the panel to reproduce dynamics and bass.

1000 watts @ 4 ohms may be a little extreme even for Maggies, but I wouldn't say they don't benefit from higher powered amps.

Do you disagree?

Steve
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post #101 of 421 Old 02-17-2011, 05:06 PM
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Taken from Audioholics review of the Yamaha RX-A3000


Interestingly enough the RX-A3000 delivered similar dynamic power output ACD into 8 ohm loads and slightly more power two channels driven into 4 ohm loads than the Emotiva UPA-7 dedicated multi-channel power amplifier
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post #102 of 421 Old 02-17-2011, 05:47 PM
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Originally Posted by DenPureSound View Post

JHAz -- that is part of what started this discussion of EMO Power Ratings, etc. I pushed my Denon AVR-3311CI driving FL/FR/C/SL/SR Klipsch's w/sensitivities at 98db in Multi Ch Stereo Mode, and the Denon PROTECTED itself and shut down at +12db (Never made it to +18db) -- now was it loud yes, and clipping YES... totally distorted and thermal runaway on the Denon, and it SHUT DOWN. BTW - I love the front end of the Denon for Pre/Pro, and it has a lot of nice features, but not for any degree of power in a 5.1 or 7.1 as is the case here.

So, that is what this thread is about POWER discussions on the Emotiva Amps.

I'm just wondering why would you turn it up to +12? Do you actually plan on listening to music or movies that loud? I don't know anybody who watches movies in the pluses. Also, all channel stereo is not really an accurate depiction of what's going on in a 7.1 movie. You will rarely have that much happening in all 7 channels. I'm just wondering because I have a 3310 with some 90db paradigms and I've never had any problems with clipping. My room is small (11 x 13) but those Klipsch are very efficient. Were you running a sub with the speakers set to small or did you have them set to large?
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post #103 of 421 Old 02-17-2011, 06:04 PM - Thread Starter
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Originally Posted by mjpearce023 View Post

I'm just wondering why would you turn it up to +12? Do you actually plan on listening to music or movies that loud? I don't know anybody who watches movies in the pluses. Also, all channel stereo is not really an accurate depiction of what's going on in a 7.1 movie. You will rarely have that much happening in all 7 channels. I'm just wondering because I have a 3310 with some 90db paradigms and I've never had any problems with clipping. My room is small (11 x 13) but those Klipsch are very efficient. Were you running a sub with the speakers set to small or did you have them set to large?

MJPearce023,
+12db listening in Multi Ch. Stereo running 5.1 (.2) with dual subs, and listening to LoverBoy music recorded in two ch., not a movie. Room size here is 22' x 28' x 9-10' Sloping ceilings -- all spkrs. were set to Small, except the fronts at that time. We were just seeing what the AVR-3311CI would do if it had to drive ALL Five Klipsch's, and we found out for sure, as it never made it to +18db which I was glad it did Protect, as it was Super Loud and very Distorted at +12db just prior to shutting itself down. So that is the story of the Denon AVR-3311CI here.
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post #104 of 421 Old 02-17-2011, 06:44 PM
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Originally Posted by Gene DellaSala View Post

No need to test an XPA-5 when I already tested an XPA-2 and they are so similar. With Emotiva changing and upgrading amps so frequently, I will wait for their next model lineup to do another review.



That is why I still do ACD testing despite its not a typical real world usage scenario.



We do both

The CEA Burst testing I do is very similar to how THX does their power testing and is much closer to music program material than a continuous sinewave sweep test.



Yes try to avoid receivers that don't have a discrete amp section. I was glad Yamaha replaced the 665 with the 667 after I hammered them on it here:

Trading Amplifier Quality for Features

Gene what is the duration time for all of these test? Is the time standard, do the print publication and manufacturers use the same times? And who if anyone governs everyone is on the same page?

Also this statement that you make that there is no need to test the XPA-5 since you have already tested the XPA-2? The XPA 2 uses a different amp module and has 1200VA available to produce 600watts @8 ohms and 1000watts @ 4 ohms. This does not compare to the XPA-5 that has 1200VA available to produce 1000watts @ 8ohm and 1500watts @4ohms. What is the basis for this statement?
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post #105 of 421 Old 02-17-2011, 07:33 PM
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Originally Posted by DenPureSound View Post

Ok, so we are BACK to the XPA-5 MODEL with ACD Simultaneously and it states Continuously also... how do they get 1,000 Total Watts RMS into 8 Ohms per Channel with a 1200VA Xformer, using a Class A/B design????

Class AB designs will be at their peak efficiency at full output power, 70% wouldn't be an outlandish number for efficiency at that point which works out to 1430W from the wall to drive 1000W, a 1200VA transformer could supply that for shortish periods.

The efficiency of class AB designs suffers when they are operated at lower power levels with efficiency at low volume being flat out terrible and max power dissipation occurring in the neighborhood of 50% max output.

In reality amps don't spend much time at full power so the "real world" efficiency of a class AB design is much lower which is the 35-50% type numbers that usually get quoted. Even thats at around half of max output. At maybe 10% of max output the efficiency probably like 5-10% if that.
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post #106 of 421 Old 02-17-2011, 09:18 PM
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Originally Posted by DenPureSound View Post

MJPearce023,
+12db listening in Multi Ch. Stereo running 5.1 (.2) with dual subs, and listening to LoverBoy music recorded in two ch., not a movie. Room size here is 22' x 28' x 9-10' Sloping ceilings -- all spkrs. were set to Small, except the fronts at that time. We were just seeing what the AVR-3311CI would do if it had to drive ALL Five Klipsch's, and we found out for sure, as it never made it to +18db which I was glad it did Protect, as it was Super Loud and very Distorted at +12db just prior to shutting itself down. So that is the story of the Denon AVR-3311CI here.

Thats a huge room. Yea you probably do need a emo for a room that big. You made a good call with the Klipsch for a room that size. Those horns will do alot better that a dome tweeter could have. I think the amps in the 3311 would be good for most medium size rooms but not anything that big.
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post #107 of 421 Old 02-17-2011, 09:45 PM
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Originally Posted by xianthax View Post

Class AB designs will be at their peak efficiency at full output power, 70% wouldn't be an outlandish number for efficiency at that point which works out to 1430W from the wall to drive 1000W, a 1200VA transformer could supply that for shortish periods.

The efficiency of class AB designs suffers when they are operated at lower power levels with efficiency at low volume being flat out terrible and max power dissipation occurring in the neighborhood of 50% max output.

In reality amps don't spend much time at full power so the "real world" efficiency of a class AB design is much lower which is the 35-50% type numbers that usually get quoted. Even thats at around half of max output. At maybe 10% of max output the efficiency probably like 5-10% if that.

It's a good point to make. People assume AB amps are more inefficient than they are, when they at max power.

One of the main reasons for the inefficiency in class AB amps is that the transistors are being fed with full rail voltage all the time regardless of how much current they are drawing.

"But this one goes up to 11"
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post #108 of 421 Old 02-18-2011, 07:01 AM
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Originally Posted by ss9001 View Post

Even for electrostats and inefficient planars like Magnepan?

The vast majority of Maggie owners would disagree with you on this.

My own experience with their middle speaker in their line, the 1.6QR, was that while my 140 watt 8 ohm receiver drove them, going to an amp with 300 watts at 8 ohms allowed transients like the action on piano keys, percussive drum thwacks, all came through more clearly with the higher power driving the speaker. It's possible that the receiver was power supply limited at 4 ohms but I was only listening to 2 Ch and bench tests showed it was capable of >200 watts 4 ohms, 4 channels driven - but like this discussion, who knows what the test conditions were.

In every listening comparison I did except 1 Peter Gabriel recording where I couldn't tell any difference, the speaker responded better with the higher powered amp: the massed choral part of Beethoven's 9th was less congested, percussion attacks in Dire Straits Brothers in Arms, piano in various recordings both classical & jazz, all sounded better with the 300/600 watt amp at same volume settings. I didn't have a db SPL meter then, but I left the volume control on the receiver the same. If it wasn't exact, it was darn close to being same.

I agree with you that the vast majority of conventional dynamic speakers even if 4 ohms don't need nearly that much power, but planars & electrostats are a different story. Stats need hi-current, and planars benefit from hi power to drive the panel to reproduce dynamics and bass.

1000 watts @ 4 ohms may be a little extreme even for Maggies, but I wouldn't say they don't benefit from higher powered amps.

Do you disagree?

When posting that point, I knew someone would reply with the Maggie POV

No doubt they need a ton of power because they have extremely low sensitivities but you should measure the distortion when the Maggies have that much power.

two things I believe after spending thousands of hours testing drivers, reading and playing around with speaker designs. Massive power requirements have huge SQ issues and low sensitivity driver choices are not a good choice if dynamics matter.

NOTE: The Maggies are incredible sounding speakers when driven within their limits, one of my favorite sounding designs but I would never consider them a good choice for HT dynamics.

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post #109 of 421 Old 02-18-2011, 08:20 AM - Thread Starter
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Quote:
Originally Posted by Gene DellaSala View Post

No need to test an XPA-5 when I already tested an XPA-2 and they are so similar. With Emotiva changing and upgrading amps so frequently, I will wait for their next model lineup to do another review.



That is why I still do ACD testing despite its not a typical real world usage scenario.



We do both

The CEA Burst testing I do is very similar to how THX does their power testing and is much closer to music program material than a continuous sinewave sweep test.



Yes try to avoid receivers that don't have a discrete amp section. I was glad Yamaha replaced the 665 with the 667 after I hammered them on it here:

Trading Amplifier Quality for Features

Gene DellaSala -- with all do respect, and I am an Audioholics User also, the XPA-5 and the XPA-2 from Emotiva, ARE NOT SIMILIAR at ALL such as:

XPA-2: 300W RMS @ 8 Ohms x 2
XPA-5: 200W RMS @ 8 Ohms x 5

XPA-2: Total Power Out = 600W RMS @ 8 Ohms
XPA-5: Total Power Out = 1,000W RMS @ 8 Ohms

Different secondary capacitance as:

XPA-2: 45,000uF
XPA-5: 60,000uF

Output Devices per Ch.:
XPA-2: 12 per Ch.
XPA-5: 6 per Ch.

The biggest issue in my right mind is both Models have the 1,200VA Xformer, but look at the Power Output of the XPA-5 at 1KW Output -- how can EMO get that magnitude of power continuously from their XPA-5?

The reason it would be GREAT if you TESTED the XPA-5, is many are questioning how EMO with a Class A/B design can get 200W RMS into 8 Ohms x 5 Channels ACD from that Xformer and they state Continuously per their X-Series Manual on Pg.10.

My previous calc's. show that it is Not Possible for the EMO XPA-5 to produce 1KW into 8 Ohms CONTINUOUSLY -- another reason for a Bench Test Review.

Gene - give it some deep thought there, as it could be a while before their new line comes out also.

Dennis
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post #110 of 421 Old 02-18-2011, 08:27 AM
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No offsense, but why do you keep questioning continuous all channels driven power of their amp specs? I think evidence strongly suggests their definition of continuous is not the same as FTC (5 mins.) And that they tested using sweeps for all their multi-channel amp.

If you are simply trying to get Emotiva to confess to some theoretical lie, they won't. They have already been questioned on this, and answered the questions.

"But this one goes up to 11"
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Originally Posted by xianthax View Post
Class AB designs will be at their peak efficiency at full output power, 70% wouldn't be an outlandish number for efficiency at that point which works out to 1430W from the wall to drive 1000W, a 1200VA transformer could supply that for shortish periods.

The efficiency of class AB designs suffers when they are operated at lower power levels with efficiency at low volume being flat out terrible and max power dissipation occurring in the neighborhood of 50% max output.

In reality amps don't spend much time at full power so the "real world" efficiency of a class AB design is much lower which is the 35-50% type numbers that usually get quoted. Even thats at around half of max output. At maybe 10% of max output the efficiency probably like 5-10% if that.

===================================

Yes, I AGREE that it can produce 1KW for only for a short period of time, and during that time the 1200VA Xformer is overdriven -- the difference here is CONTINUOUS or Only for a Short Period of Time --

EMO states VERY CLEARLY on Pg. 10 of the X-Series Manual that their Power Ratings are CONTINUOUS (But with NO Mention of the TIME DOMAIN).

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Quote:
Originally Posted by MichaelJHuman View Post

No offsense, but why do you keep questioning continuous all channels driven power of their amp specs? I think evidence strongly suggests their definition of continuous is not the same as FTC (5 mins.) And that they tested using sweeps for all their multi-channel amp.

If you are simply trying to get Emotiva to confess to some theoretical lie, they won't. They have already been questioned on this, and answered the questions.

With all do respect MJHuman -- please read Pg. 10 of the X-Series Manual, in which they discuss PEAK vs. CONTINUOUS POWER RATINGS. And, it clearly states they EMO do not play games with the specifications, and the rest you should read to get a very clear understanding of what I am stating -- CONTINUOUS is the Issue here, is it not?
Your all right MJH...
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post #113 of 421 Old 02-18-2011, 08:36 AM
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Quote:


Gene DellaSala -- with all do respect, and I am an Audioholics User also, the XPA-5 and the XPA-2 from Emotiva, ARE NOT SIMILIAR at ALL such as:

XPA-2: 300W RMS @ 8 Ohms x 2
XPA-5: 200W RMS @ 8 Ohms x 5

XPA-2: Total Power Out = 600W RMS @ 8 Ohms
XPA-5: Total Power Out = 1,000W RMS @ 8 Ohms

Different secondary capacitance as:

XPA-2: 45,000uF
XPA-5: 60,000uF

Output Devices per Ch.:
XPA-2: 12 per Ch.
XPA-5: 6 per Ch.

The biggest issue in my right mind is both Models have the 1,200VA Xformer, but look at the Power Output of the XPA-5 at 1KW Output -- how can EMO get that magnitude of power continuously from their XPA-5?

The reason it would be GREAT if you TESTED the XPA-5, is many are questioning how EMO with a Class A/B design can get 200W RMS into 8 Ohms x 5 Channels ACD from that Xformer and they state Continuously per their X-Series Manual on Pg.10.

My previous calc's. show that it is Not Possible for the EMO XPA-5 to produce 1KW into 8 Ohms CONTINUOUSLY -- another reason for a Bench Test Review.

Gene - give it some deep thought there, as it could be a while before their new line comes out also.

The basic amplifier design between the two models is the same only the XPA-2 doubles up on output devices. Their gain structures are very similar.

I've tested virtually all of Emotiva's amps and found their power ratings for 1/2CH driven are quite conservative while the ACD are usually a bit off, most likely do to how they test (using a VARIAC to hold line voltage constant) vs how I test it (typical 20A consumer outlet & no line regulation). Their way will always yield higher power #s.

I could review an XPA-5, but people here will likely complain that we review too many Emotiva amps.

After finishing up my audio tests for the Oppo BDP-93/95, I think I will pick another amp brand to test and revisit Emotiva next time around.

Best Regards;

Gene DellaSala (GDS)
President, Audioholics.com
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Quote:
Originally Posted by xianthax View Post

Class AB designs will be at their peak efficiency at full output power, 70% wouldn't be an outlandish number for efficiency at that point which works out to 1430W from the wall to drive 1000W, a 1200VA transformer could supply that for shortish periods.

The efficiency of class AB designs suffers when they are operated at lower power levels with efficiency at low volume being flat out terrible and max power dissipation occurring in the neighborhood of 50% max output.

In reality amps don't spend much time at full power so the "real world" efficiency of a class AB design is much lower which is the 35-50% type numbers that usually get quoted. Even thats at around half of max output. At maybe 10% of max output the efficiency probably like 5-10% if that.

OK, I agree with you for "Shortish Periods" ???

What does that mean in a TIME Measurement, secs/mins/hrs/days or What?

EMO states CONTINUOUS -- to me that is not just a Shortish Period of Time??
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Originally Posted by penngray View Post

I have owned Emotiva amps (XPA-5, LPA-5), I have also owned their speakers and the LMC-1... I do not own any of them any more.

All your points are great but the XPA1 and XPA-2s are not really great values at all, I think their XPA-1 and XPA-2 are a waste of $$$.

1. Running that much power into main speakers is silly, the amount of compression/distortion in most cases is too high. People that think they need all that power seldom have any idea about their speaker designs and what is really happening at those high voltage levels.


2. If we want that much power then we go with proven pro audio amps. The XPA-1 and XPA-2 are overpriced compared to valid pro options. I guess people are just paying for comercial looks.

OK, Penngray, give us your proven pro audio amp recommendations if you have given up on Emotiva, and why would you recommend those mfg's. and models?
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FROM MJHuman -- I TOTALLY AGREE W/ ALL THAT YOU STATED!!
JUST WANTED TO REPEAT IT FOR ALL AGAIN ...

* Avoid those sub $400 receivers. For example, look at how Yamaha's 667 is a nice step up from the 567, and ask if it's worth the better power supply.

* Buy whatever receiver meets your needs, but consider something with pre outs. If after spending time with your system, you conclude you are too demanding for the receiver, add some external amps - there are affordable options out there.

* Don't buy $1000+ receivers for power only. You are starting to reach the limits of receiver power in that price range, and are heavily paying for top end VP, network features and such. May as well reconsider options that involve a cheaper receiver that meets your needs then add external amps.

* Shooting for reference level is going to cost you. You need very good subwoofer(s,) substantial power, and speakers that can get it done. If you are pragmatic about it, you can get within 6 dB or so for less money. You are pushing the laws of diminshing returns as you push towards reference level SPL.
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Quote:
Originally Posted by Gene DellaSala View Post

The basic amplifier design between the two models is the same only the XPA-2 doubles up on output devices. Their gain structures are very similar.

I've tested virtually all of Emotiva's amps and found their power ratings for 1/2CH driven are quite conservative while the ACD are usually a bit off, most likely do to how they test (using a VARIAC to hold line voltage constant) vs how I test it (typical 20A consumer outlet & no line regulation). Their way will always yield higher power #s.

I could review an XPA-5, but people here will likely complain that we review too many Emotiva amps.

After finishing up my audio tests for the Oppo BDP-93/95, I think I will pick another amp brand to test and revisit Emotiva next time around.

Gene -- Thank you for your post here. If you pick another Amp Mfg. to test, hopefully you would pick the next closest Mfg'd. one with the smallest Quotient ($ / Total Watts Out). In other words, a multi-channel amp closest to Emotiva at around $0.90 / Watt (EMO's XPA-5: $899/1KW) or a shade higher you will most likely end up at for sure, but closer to EMO's comparative Mktg. Cloud Price Point.
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Quote:
Originally Posted by Gene DellaSala View Post

After finishing up my audio tests for the Oppo BDP-93/95, I think I will pick another amp brand to test and revisit Emotiva next time around.

Anthem or Parasound, perhaps?

AJ
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post #119 of 421 Old 02-18-2011, 09:31 AM
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Originally Posted by DenPureSound View Post

With all do respect MJHuman -- please read Pg. 10 of the X-Series Manual, in which they discuss PEAK vs. CONTINUOUS POWER RATINGS. And, it clearly states they EMO do not play games with the specifications, and the rest you should read to get a very clear understanding of what I am stating -- CONTINUOUS is the Issue here, is it not?
Your all right MJH...

I read all those statements on their web page. Marketing spin, IMO. I would not go as far as calling them liars. They really seemed to believe that they way they measured their amps was fair (based on the thread in the lounge comparable to this thread.)

Eventually they just sort of took a final stand. And stopped discussing it.

Trying to paraphrase them, they were saying that continuous did not have to mean it could hold that power for minutes at a time because that's unrealistic, does not reflect real world signals, etc.

Even reading into what I think they are trying to potray a bit more...that their rated power per channel is conservative with real world material, because not all channels will be hitting peak signal level at the same time, so as long as they can put out at least 200 watts / channel as needed under real world conditions, they have given you a fair rating.

Proving that is a bit difficult, because even if it was true for one movie, is it true for all movies? Is there a movie where 5 channels are all at near peak level at the same time and keeps hitting that peak every so many miliseconds for long enough to drain the caps to the point that the amp clips? Or that many channels peaking or near peaking cause the limiters to kick in, thus causing clipping?

I have no idea. But in their minds, I think, they have given you a fair power rating. I could be wrong. They could be spinning this.

We know some companies will always rate their amps more conservatively than others. That's a given. Emotiva is not the most conservative with their measurements I think we can say with some certainty.

"But this one goes up to 11"
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post #120 of 421 Old 02-18-2011, 09:34 AM
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Originally Posted by DenPureSound View Post

OK, I agree with you for "Shortish Periods" ???

What does that mean in a TIME Measurement, secs/mins/hrs/days or What?

EMO states CONTINUOUS -- to me that is not just a Shortish Period of Time??

They discussed what they think continuous RMS means.

Here is a quote from Lonnie when asked about continuous...

"In short, no. Why would you run an amp at full power on all channels for 4 hours? What would this prove? What useful information could be derived from this when it is never used in this way? Music by nature is dynamic and not continuous so a 4 hour full power test would not result any useful data so what would be the point? "

This is the thread I read discussing the topic of continuous -

http://emotivalounge.proboards.com/i...d=12891&page=1
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