Stream of consciousness buying process, or Talk me off the "inaudible" cliff.

[day7a1]

(Note: This started with a question, but as is often the case the more I got into exactly I was trying to ask the closer I got to just answering the thing myself, which I believe I did. So here is my thought process open for correction, notes, questions, or other critique/discussion.)

So I love this forum but one thing that I'm not sure is super clear is just how good is good. Of course, that clearly depends on budget and power when it comes to amplifiers, but I have 3 amps that I'm trying to decide between for a particular set of speakers. All 3 are reasonable and affordable, but the highest priced one is nearly twice the price of the lowest (I'm naturally inclined towards "cheapskate"). I think it's in the spirit of this forum to discuss how much SINAD is worth in tangible and intangible assets. I think the general and reasonable consensus is that it's worth a lot up until the point where it's not really worth anything.

None of the three have specifically been tested here, but the 2nd and 3rd have tests of the modules in different applications. If it matters the particular brands are Emotiva PA-1 for 1 and the Apollons for 2&3. I need rack mountable units so if you have better recommendations please make sure that criteria is hit.

Speakers will be the Revel M126Be, 86dB sensitivity. "Recommended power of 50-150 watts", whatever that means. 150W is 110.77dB@1m.

Listing the modules and not the manufacture, I'm choosing between the
1) ICEpower ASC300, $639 USD (after discount), .two 135w @8 ohm channels (.1%THD)..................... SNR 112dB (135W) 91dB (1W). SINAD 86dB(1W 4 Ohms)
2) NC252MP, ...............$959 USD (shipped).............. two 200w @8 ohm channels (125@91dB SINAD). SNR 113dB (246W)....................... SINAD ~86dB(1W 4 Ohms)
3) NC502MP, ...............$1042 USD (shipped).............two 350w @8 ohm channels (270@ 87dB SINAD).SNR 127dB (445W?)..................... SINAD ~94dB (1W 4 Ohms)

So 1&2 are so close in measurements that I may as well get 1, but 2&3 are so close in price that I may as well get 3. So what's the audible difference between the 1 and 3? Given the similarity in specs can we approximate 2 for 1?

For 2 minimum distortion occurs at 100W 8 Ohms and is -100dBFS THD+N. For 3, the same spec is 2W and -101dBFS. However, at 100W 3's distortion is ~ -90dBFS. 100W is 110.77dB@1m.

Full 16 bit resolution is 96dB peak. Using the Homestead calculator , near a wall, and at an insanely large 20ft distance, 96dB happens to be 100W. That's convenient...

Thus, minimum distortion at maximum practical output levels can best be achieved with amp 2 which has similar stats to amp 1, which is considerably less expensive than amp 3. Caveat is that distortion curves are similar. NC252MP distortion curve appears to be typical. It is unlikely that ASC300 distortion curve is atypical. Consequence of atypical distortion curve is low. Risk of incorrect assumption is negligible. Risk of spending 1.6x more is unlikely to be parity.

 

[garbulky]

(Note: This started with a question, but as is often the case the more I got into exactly I was trying to ask the closer I got to just answering the thing myself, which I believe I did. So here is my thought process open for correction, notes, questions, or other critique/discussion.)

So I love this forum but one thing that I'm not sure is super clear is just how good is good. Of course, that clearly depends on budget and power when it comes to amplifiers, but I have 3 amps that I'm trying to decide between for a particular set of speakers. All 3 are reasonable and affordable, but the highest priced one is nearly twice the price of the lowest (I'm naturally inclined towards "cheapskate"). I think it's in the spirit of this forum to discuss how much SINAD is worth in tangible and intangible assets. I think the general and reasonable consensus is that it's worth a lot up until the point where it's not really worth anything.

None of the three have specifically been tested here, but the 2nd and 3rd have tests of the modules in different applications. If it matters the particular brands are Emotiva PA-1 for 1 and the Apollons for 2&3. I need rack mountable units so if you have better recommendations please make sure that criteria is hit.

Speakers will be the Revel M126Be, 86dB sensitivity. "Recommended power of 50-150 watts", whatever that means. 150W is 110.77dB@1m.

Listing the modules and not the manufacture, I'm choosing between the
1) ICEpower ASC300, $639 USD (after discount), .two 135w @8 ohm channels (.1%THD)..................... SNR 112dB (135W) 91dB (1W). SINAD 86dB(1W 4 Ohms)
2) NC252MP, ...............$959 USD (shipped).............. two 200w @8 ohm channels (125@91dB SINAD). SNR 113dB (246W)....................... SINAD ~86dB(1W 4 Ohms)
3) NC502MP, ...............$1042 USD (shipped).............two 350w @8 ohm channels (270@ 87dB SINAD).SNR 127dB (445W?)..................... SINAD ~94dB (1W 4 Ohms)

So 1&2 are so close in measurements that I may as well get 1, but 2&3 are so close in price that I may as well get 3. So what's the audible difference between the 1 and 3? Given the similarity in specs can we approximate 2 for 1?

For 2 minimum distortion occurs at 100W 8 Ohms and is -100dBFS THD+N. For 3, the same spec is 2W and -101dBFS. However, at 100W 3's distortion is ~ -90dBFS. 100W is 109.01 110.77dB@1m.

Full 16 bit resolution is 96dB peak. Using the Homestead calculator , near a wall, and at an insanely large 20ft distance, 96dB happens to be 100W. That's convenient...

Thus, minimum distortion at maximum practical output levels can best be achieved with amp 2 which has similar stats to amp 1, which is considerably less expensive than amp 3. Caveat is that distortion curves are similar. NC252MP distortion curve appears to be typical. It is unlikely that ASC300 distortion curve is atypical. Consequence of atypical distortion curve is low. Risk of incorrect assumption is negligible. Risk of spending 1.6x more is unlikely to be parity.

For your budget - I would reccomend a pair of Emotiva PA-1 monoblocks (which use the Ice ASC300 module). At $315 each you get it for $630 for a pair of monoblock amps. I've personally used them extensively and have compared them to the Emotiva XPA-1 (1000 watts @ 4 ohm) monoblocks. Imo the PA-1's are close to the same quality - and the XPA-1 is the best amp I've heard.

I have heard the Revel's. Are you sold on them? Because though they sound great.... for their asking price, I've heard speakers at a fraction of the price that sound either just as good or better. Plus the Revel's will need a sub.
For example- the Emotiva T2 go a whole lot louder and a whole lot lower at about the same quality for a $1000. So does the T1 r the Axiom M5HP bookshelves (1000) with available real wood/gloss finish. Imo the equivalent to the Revel is the Emotiva Airmotiv 6 speaker which are out of stock but you can get used with a transferrable warranty for about $500 (and they don't necessarily need a sub or amps)

 

[day7a1]

Are you sold on them?

I happened upon a deal on them for a set of open boxes. I was not sold on them at $4k, but for a bit more than half that, I was. Subs were always intended. I do not have a room nor will I have a room that doesn't change every 2-3 years for the next 20 years. I needed bookshelves that were designed to be good in any room and whether or not the Revels are the best or the cheapest in that regard, they are the most transparent about that being the goal and the steps they took to achieve it.

I don't think the Airmotiv 6 are out of stock, it looks like they're no longer made. Floorstanders are right out.

I would reccomend a pair of Emotiva PA-1 monoblocks

That is in fact what I had decided in the post. However, what is the next step up in budget that you may recommend?My budget may be more than you realize. I just don't believe that price/performance =1.

Edit: Added question mark.

 

[garbulky]

I happened upon a deal on them for a set of open boxes. I was not sold on them at $4k, but for a bit more than half that, I was. Subs were always intended. I do not have a room nor will I have a room that doesn't change every 2-3 years for the next 20 years. I needed bookshelves that were designed to be good in any room and whether or not the Revels are the best or the cheapest in that regard, they are the most transparent about that being the goal and the steps they took to achieve it.

I don't think the Airmotiv 6 are out of stock, it looks like they're no longer made. Floorstanders are right out.


That is in fact what I had decided in the post. However, what is the next step up in budget that you may recommend?My budget may be more than you realize. I just don't believe that price/performance =1.

Edit: Added question mark.

If you already have the Revel's I suggest you enjoy them Congrats! They reminded mme a lot of the sound signature of the Sonus Faber Sonetto VIII (with less bass).

As for amps, I can only recommend what I have heard or used myself. I evaluate things subjectively - no dbt - so keep that in mind.
The PA-1 lies very close to the best amp I've heard which is the Emotiva XPA-1 gen 2. I have heard a good bit of other great amps so I was quite surprised as to the sound. For example, I find myself liking the PA-1's better than the Yamaha S2000, Bob Latino tube monoblocks, any receiver, Emotiva XPA-1 L, Basx A-300, XPA-2 gen 3, Crown XLS drivecore, Hegel H30, Peachtree Decco, Nakamichi Stasis class A etc. So it's hard to say if anything is a worthwile upgrade.

Back to back, the PA-1's sound is a slightly tonally different version of the XPA-1 gen 2. Both sound quite excellent with my speakers (Axiom Audio M80). The XPA-1 produces a bit more of a heft to the sound with powerful bass and slightly better clarity in some ways while the PA-1's sound slightly "airier" on the treble and slightly clearer in some small aspects. Think of it as being the "delicate" version of the XPA-1 gen 2. For large hard to drive speakers, the XPA-1 gen 2 takes the edge due to its tremendous power - I've been unable to max it out or make it strain. But the PA-1 is a serious amp for a seriously great price imo. I would drive it fully balanced because I did get one report of somebody using the unbalanced adapter and encountering a hum.

For your speakers though, the XPA-1 gen 2 may be completely unnecessary. BTW, don't bother with the current gen 3 Emotiva amps because they don't sound as good as the PA-1 amps.
Amps that I do wish to hear is the Hypex Nc400 amps.
FWIW: A used XPA-2 gen 2 is on sale on the Emotiva Forums for $600. I find it to be very close to the XPA-1 sound. They are robust amps that imo are long lived.

Your real upgrade for your speakers would be dual subwoofers (for smoother not louder bass) and a good amount of room treatment imo. Enjoy

 

[Ron Texas]

Yeah, if you want IcePower with 135W @ 8ohms, Emotiva is the way to go. Want Hypex? they measure better, but I doubt they sound much better. the main difference is Emotiva is in the USA and all these outfits assembling Hypex (at low prices) are in Europe. Note, the PA-1 has a higher sensitivity, making them easier to use with an unbalanced DAC. The Revels should be enough to keep anyone happy, but you will be happier with a a sub (or 2). Enjoy.

 

[day7a1]

you will be happier with a a sub (or 2).

I already plan to get 2 subs. Hsu Research is the only one I know of with balanced inputs though, which seems strange to me because all of them recommend multiple subs that could have distant placement. It's not that hard to wrap up 50' around the edges of rooms and across power cables.

Don't know if I'll be getting the ULS or VTF yet, there isn't really a significant price difference.

 

[Ron Texas]

I already plan to get 2 subs. Hsu Research is the only one I know of with balanced inputs though, which seems strange to me because all of them recommend multiple subs that could have distant placement. It's not that hard to wrap up 50' around the edges of rooms and across power cables.

Don't know if I'll be getting the ULS or VTF yet, there isn't really a significant price difference.

Perhaps noise picked up in the interconnects is above the sub's audio output range. Rythmik is popular around here.

 

[day7a1]

Rythmik is popular around here.

Thank you for that recommendation! I re-visited their product line and they do in fact have XLR inputs as options on all (I think) of their subs and as a standard option on some. They are also competitively priced with the HSUs and I think will be a better fit for my needs with the servo technology, of which I was heretofore unaware.