Emotiva XPA 2 vs Onkyo TX-SR706 for a 2.1 system!?!?!?!

[StephenM]

If you're reading this, the title did it's job. Yes, I understand that the XPA-2 has far greater power reserves than the Onkyo, and that there is no contest in terms of headroom. But this post isn't about who can muster the most juice, it's a question of how a lowly HT receiver compares against a highly regarded and very powerful two channel amplifier at volumes I care to listen at, specifically with a pair of RF-5s which dip down to 4 ohms, but not below, and are 99dB sensitive with a 2.83 watt input.

What volumes do I care to listen to? I generally listen to movies around -20dB from reference; this calls for peaks from your main speakers of 85dB. Listening to music, I've recorded peaks of 90dB or so on my SPL meter. So reasonably loud, but not obnoxiously so. As such, 90dB at the seats is what I'm aiming for.

Now like most Klipschites, my RF-5s are rated to be fairly sensitive. However, being the conservative type, I'll say that they are 95dB sensitive with a 2.83 volt input (1 watt @ 8 ohms, 2 watts @ 4 ohms). Factoring in losses for distance, and ignoring boundary gain to be further conservative, this means at 4 ohms, I need roughly 6 watts, and at 8 ohms I need roughly 3 watts, or about a 5 volt input.

Enter in measurements...of both...at 5 volts!

Emotiva, 4 & 8 ohms:

http://www.hometheaterhifi.com/images/stories/2008/december-2008/emotiva-xpa-2-amplifier-thd+n-vs-fr-4-ohms-large.gif

http://www.hometheaterhifi.com/images/stories/2008/december-2008/emotiva-xpa-2-amplifier-thd+n-vs-fr-8-ohms-large.gif

Onkyo 4 & 8 ohms:

http://www.hometheaterhifi.com/images/stories/2009/march-2009/onkyo-tx-sr706-receiver-thd-n-vs-fr-8-ohms-large.gif

http://www.hometheaterhifi.com/images/stories/2009/march-2009/onkyo-tx-sr706-receiver-thd-n-vs-fr-4-ohms-large.gif

Looking at the yellow curve, at 8 ohms, the Onkyo holds THD+N to under 0.01% until 4kHz where it rises to peak at 0.05% at 20kHz. The Emotiva holds THD+N to 0.03% until ~2kHz where it rises to peak at ~0.2% at 20kHz. For all practical purposes, either should be transparent at this level.

At 4 ohms....things don't change all that much. The Onkyo holds THD+N to under 0.02% until 3kHz where it rises to peak at 0.1% at 20kHz. The Emotiva holds around 0.04% until about 3kHz where it rises to peak at a tad over 0.2% at 20kHz. Again, for all practical purposes, this is very good.

If one looks at even lower levels of wattage, the Onkyo holds its advantage over the Emotiva:

http://www.hometheaterhifi.com/images/stories/2008/december-2008/emotiva-xpa-2-amplifier-thd+n-vs-power-8-ohms-large.gif

http://www.hometheaterhifi.com/images/stories/2008/december-2008/emotiva-xpa-2-amplifier-thd+n-vs-power-4-ohms-large.gif

http://www.hometheaterhifi.com/images/stories/2009/march-2009/onkyo-tx-sr706-receiver-thd-n-vs-power-8-ohms-large.gif

http://www.hometheaterhifi.com/images/stories/2009/march-2009/onkyo-tx-sr706-receiver-thd-n-vs-power-4-ohms-large.gif

The Onkyo also measures lower for intermodulation distortion, although both are very good:

http://www.hometheaterhifi.com/images/stories/2008/december-2008/emotiva-xpa-2-amplifier-imd-large.gif

http://www.hometheaterhifi.com/images/stories/2009/march-2009/onkyo-tx-sr706-receiver-imd-large.gif

Both are razor flat in FR into both 4 and 8 ohm loads in the audible range.

http://www.hometheaterhifi.com/images/stories/2008/december-2008/emotiva-xpa-2-amplifier-fr-large.gif

http://www.hometheaterhifi.com/images/stories/2009/march-2009/onkyo-tx-sr706-receiver-fr-large.gif

Food for thought.

[Fish]

There is a difference......If you compare in your house let us know what you think about the sound.

[StephenM]

There is a difference

Perhaps, but objectively speaking, it seems not to be in the Emotiva's favor. I would also note that since the Onkyo is a THX certified receiver, it is rather unlikely there will be any major skeletons rolling out of the closet due to basic things like crosstalk or output impedance; THX is rather tight in how they spec even midrange receivers. Of course if there are measurements proving that premise wrong, I'd be interested to see them. However, judging by the numbers, the Onkyo seems very clean within its expected performance envelope.

If you compare in your house let us know what you think about the sound.

The Emotiva isn't on my list due to lack of reliable information on how it performs into more difficult loads (1-2ohm). However, a Parasound might be in the cards depending on whether I decide to move to speakers that are more difficult to drive than my current RF-5s (ie RF-7s).

[elitedemo]

if your looking at 1-2 ohms your definitely not in the right ballpark on this comparision for both the 706 and xpa-2, the 706 just doesnt stand a fighting chance regardless the circumstances and if your looking at swapping speakers to something difficult to drive i have no doubt a xpa2 is still a decent choice but maybe xpa1s or another brand is better suited

on occasions the rf83s dip to 2.8ohms and ive had multiple receivers and a few amps on them, the xpa2 has vastly outpreformed anything else including mid range avrs and if your looking for a better preformer than a xpa2 prepare to bring your wallet

let your ears be the judge

[StephenM]

if your looking at 1-2 ohms your definitely not in the right ballpark on this comparision for both the 706 and xpa-2

I'm aware of this. My current speakers do not dip below 4 ohms and that was the context with which the comparison of Onkyo 706 vs Emotiva XPA-2 was made, combined with very low power levels. I don't pretend that the Onkyo is the equal of the Emotiva in all respects.

As far as the 1-2 ohms comment: I'm not actively looking for new speakers; however, if I were, I would probably be aiming at something like RF-7s or maybe even Palladiums. It is my understanding that either are a significant burden to bear for any amplifier, and I'd probably choose the most robust I know of in my price range. Since nothing in the Emotiva line has been tested down to 2 or 1 ohms, nor are they rated at 2 ohms, I don't include them on my list of upgrade possibilities at this time. On the other hand, I've seen the Parasound Halo A21 tested down to 1 ohm with effective output at that load, so they do make the list.

[Fish]

No Emotiva amp made that's 125 watts or better will have any trouble driving 7's beyond sane levels. The Onkyos, well I have one in my garage, that's about as close to my listening room as it will get.

[Youthman]

However, a Parasound might be in the cards depending on whether I decide to move to speakers that are more difficult to drive than my current RF-5s (ie RF-7s).

I can say that my Parasound doesn't seem to break a sweat when driving the RF-83's system. Extremely clear at high volumes. Definitely an amp with authority. I was hesitant about dropping $750 on a 10 year old amp but now I have no regrets.

[gagelle]

I would write to Emotiva tech support. The tech who answers the emails is very knowledgable and will get back to you within 24 hours.

I'm running a 200 watt EPA-3 powering 2 Cornwalls and an Academy. The sound is terrific and gets better the more I play the unit. I'm using my 90 watt HK AVR 3600 to power my rear Fortes. There is so much more power and depth in the front that it took me awhile to balance the speakers for a good sound stage. My Academy's sensitivy is only 96 db and I have more power than my ears, (or speakers) can take.

But you have a different setup and I think an Emotiva tech can stear you in the right direction.

[Rich_Guy]

I also have RF-5's so this would be a good comparison for you. I went from using an Onkyo TX-NR900 alone for 2 channel to using it with an XPA-3, it was a very nice improvement. Later after I had upgraded to using an Onkyo PR-SC885 processor I upgraded from using the XPA-3 for 2 channel to using the XPA-2 again it was another very nice improvement.

None of these ever had any problem playing as loud as I wanted that was never an issue, but each upgrade just made nice improvements at every volume level. The improvements were in clarity, detail, imaging, musically, bass and just overall sound quality. The RF-5's love the XPA-2 and together they really sound good. Also the background floor noise level is nearly dead silent with the XPA amps, quieter than when using the receiver power. Both much more refined and much more powerful, definitely a huge improvement!

[StephenM]

No Emotiva amp made that's 125 watts or better will have any trouble driving 7's beyond sane levels. The Onkyos, well I have one in my garage, that's about as close to my listening room as it will get.

Suffice it to say: if they don't rate it for 2 ohm usage, I'm not interested in using it for speakers that dip down that low. In any case, I would expect some sort of difference with RF-7s as they do dip lower in impedance than my RF-5s.

[StephenM]

None of these ever had any problem playing as loud as I wanted that was never an issue, but each upgrade just made nice improvements at every volume level. The improvements were in clarity, detail, imaging, musically, bass and just overall sound quality. The RF-5's love the XPA-2 and together they really sound good. Also the background floor noise level is nearly dead silent with the XPA amps, quieter than when using the receiver power. Both much more refined and much more powerful, definitely a huge improvement!

See that's the odd part: its the Onkyo that is measurably quieter at lower listening levels, although either are fine in this regard. I'm not sure how an amplifier affects imaging unless the channels aren't properly balanced or perhaps if there is a major crosstalk issue (which shouldn't be the case with either). So my question is: how much if it is in your head, ie: "I just got this huge 80lbs amplifier. Of course its better than my old receiver." Because from where I stand, the objective measurements don't bear it out being better at lower volume, and I'm very much an objective creature: if something sounds better, there is a clear reason as to why.

[cornfedksboy]

Maybe I missed it, but do you have any graphs that show THD with all channels driven? Per one bench test I saw the Onkyo TX-nr608 had a distortion of greater than 1% and only 1/4 the watts were output with seven channels driven immediately prior to clipping.

On the other hand, if you are only peaking at 85-90dbs from your listening position (I assume that's where your measurements came from), that's not very loud. You may not notice much of a difference (as is demonstrated by your graphs). I notice that my 82s "open up" and have additional clarity at higher volumes.

[psg]

But this post isn't about who can muster the most juice, it's a question of how a lowly HT receiver compares against a highly regarded and very powerful two channel amplifier at volumes I care to listen at, specifically with a pair of RF-5s which dip down to 4 ohms, but not below, and are 99dB sensitive with a 2.83 Volt input.

What volumes do I care to listen to? I generally listen to movies around -20dB from reference; this calls for peaks from your main speakers of 85dB. Listening to music, I've recorded peaks of 90dB or so on my SPL meter. So reasonably loud, but not obnoxiously so. As such, 90dB at the seats is what I'm aiming for.

I think you have answered your question. It would be a fun experiment to have a close-by forum member visit with an amp to try out. I have powered my Klipschorns with harman kardon avr-325 and avr-254 receivers, alone and with external amps Nikko Alpha 220, Carver M4.0t and Monster Signature MPA-2250. Except for noise floor (unbearable on the Carver and Monster, best on the 20-year old Nikko), they all sound the same to me.

[StephenM]

Maybe I missed it, but do you have any graphs that show THD with all channels driven?

Not from Secrets of HT & Hifi, but Sound and Vision tested the 706 as well. They show that it put out 75WPC into 5 channels for half a second before it went into protection. Of course, since I'm running 2.1 only, with no great desire to move to 5 or 7.1, it makes little difference to me. Maybe if I hit the lotto and can afford a Palladium 7.1 setup; until then, I'd prefer to upgrade the quality of my mains and get truly great speakers as opposed to having 5 or 7 pretty good speakers. Personal opinion of course.

On the other hand, if you are only peaking at 85-90dbs from your listening position (I assume that's where your measurements came from), that's not very loud.

It's funny how opinions of what is loud varies so much. Suffice it to say, with music, 90dB peaks with average levels of 80dB (country & rock music) is loud enough for me, and my wife has no problems making out what I'm listening to at night from 2 floors up. Of course with movies, -20dB from reference theoretically indicates 85dB peaks for the main channels, but 95dB for LFE (subwoofer volume will be a little more since my speakers are set to small and crossed at 50Hz).

You may not notice much of a difference (as is demonstrated by your graphs).

Indeed, and that's the point of it all. Of course, my test is very narrow: most people don't have speakers quite as efficient; not all speakers have an impedance minimum of 4 ohms; probably very few people stick with 2 channels; not everyone is satisfied with my volume levels; etc. But, it is interesting data, at least to me, and maybe to someone else, which is why I posted it.

[cornfedksboy]

Thanks for the response. I have to agree with what you stated in that there would be little, if any, audible difference in a 2.1-channel set-up between your Onkyo and a quality large amp at those levels. That type of power just isn't waranted under those conditions.

I did recently read that about 50% of participants in a study considered music played at 95 db at the listening position to be a normal to quiet listening level while 50% considered it to be too loud.

Also, the 75 watts in the S&V article at five channels driven is quite consistent with other articles I've read on Onkyo's. They didn't do 7 channels study, which drops it under 30 wpc. Also, they didn't list the THD prior to clipping which is greater than 1%. Lastly, they only did it at one frequency, 1 KHz. I found (subjectively) that my Marantz produces much "cleaner" sound in the lower frequencies than my Onkyo.

Again, though, you were very clear in what you were reviewing...2-channels driven at a moderate level. I can't really argue with any of the data being untrue under those test conditions. Thanks for sharing!

[Fish]

No Emotiva amp made that's 125 watts or better will have any trouble driving 7's beyond sane levels. The Onkyos, well I have one in my garage, that's about as close to my listening room as it will get.

Suffice it to say: if they don't rate it for 2 ohm usage, I'm not interested in using it for speakers that dip down that low. In any case, I would expect some sort of difference with RF-7s as they do dip lower in impedance than my RF-5s.

I don't really understand the point of the whole thread, it's not important that I do I know.Is it that large amps are not needed at low volume??, I think that's well known.Is it Onkyo is as good as Emotiva? you may get a very few bites.If you want a big honkin' 2ohm load amp why would you ever purchase an Onkyo product which can never tell the truth about numbers which don't really matter to start with.I have 125watts on 7's that I am sure will bust them apart if I choose to crank it and leave it long on heavy rock passages sometime after I've went deaf.I've also had 550 watts per ch on my 7's but it didn't matter because I can only listen so loud.

[StephenM]

I don't really understand the point of the whole thread

Simply a performance (mis)matchup between two unlikely contenders in a very specific set of circumstances for informative purposes.

Is it that large amps are not needed at low volume??, I think that's well known.

Surely; some get by on just a few watts from some amplifiers. However, it still takes a good quality amplifier to deliver good sound, high powered or otherwise, which leads to...

.Is it Onkyo is as good as Emotiva?

Within the context of this test, absolutely. Of course, if we look at quality with the amplifier swinging 40V continuously, obviously things change considerably, with the Onkyo going into protect mode and the Emotiva comfortably cruising along. But with efficient, moderately easy to drive speakers and reasonable volume requirements, the Onkyo's measurements show it to be a very good quality amplifier, on par with a very good separate 2 channel amplifier.

.If you want a big honkin' 2ohm load amp why would you ever purchase an Onkyo product

I wouldn't, nor have I ever stated I would.

[Fish]

One final ? Is this "test" on paper, in a book or graph or is this after listening? Listening is the only test that matters,ever.

[StephenM]

Is this "test" on paper, in a book or graph or is this after listening?

This test is based on measurements taken by Secrets of Home Theater and High Fidelity, and projecting performance amplifier performance into a very specific speaker load/sensitivity and volume requirement. It is not meant to be a thorough review of both pieces of equipment; just something worth thinking about in a forum filled with people who do have highly sensitive speakers, some of which present an easy load to an amplifier, and possibly some of which don't listen at ear bleeding levels.

Listening is the only test that matters,ever.

Surely; whatever makes you happy is all that really matters in the end. And lets face facts, not everyone has or is interested in such detailed information on their amplifiers, nor of their speakers; all they have left is listening.

Conversely, sighted, non-level matched comparisons are hardly a scientific way to pick which amplifier is objectively better. Measurements very much do help in this regard. Do the few measurements I've provided cover every last detail of performance? Obviously not. However, it does give a reasonably good indicator of how the amplifiers perform relative to one another, at the voltage and impedance levels I've chosen.

Personally, that they measure closely, even within the limited confines of this post, was a little surprising given how superior separates are supposed to be, even at low volumes, and how well regarded the XPA-2 is. Of course, I'm not entirely shocked either: THX Select certification is a stringent process, and frankly this test confirms to me that it is worth something. Just for interests sake, here is a 20V test of a Denon that retailed for $1500 into 4 and 8 ohms. It is not certified by THX. Feel free to compare with the less costly Onkyo.

http://www.hometheaterhifi.com/images/stories/2009/november-2009/Denon-AVR-3310CI-Receiver/denon-avr-3310ci-receiver-thd-plus-n-vs-fr-large.gif

While Secrets doesn't give the 5 volt curve for whatever reason, judging by the abysmal 20V/4 ohm performance, this probably wouldn't be a product I'd care to own.

[Fish]

"All they have left is listening"

That's the start and stop for everyone I've known in 40 years of caring.If you don't like the sound for whatever reason numbers won't seal the deal.Now...there could be only two amps, one for loud jammers and one for quiet listeners.I'm sure you know there are numerous makers of amps etc...the reason is there is an element out there that thinks there is a difference at any level.There must be lots of em' cause there are lots of companies.

After saying all that...there is way more similar in amps than differences I agree.I could take a number of amps and do the job from low to high dollar that sound similar.The big differences are source ,preamp ,that's where avrs fall of the list and stop the 706 etc...from futher serious listening consideration, imo.