Emotiva UPA 200 or XPA 200 to drive Sierra Towers

[AcuDefTechGuy]

That is an interesting analysis.
To properly analyze this, I have trying to get handle on the dynamics of music.
The more dynamic the greater the peak requirements.

The more compressed music should fit within the RMS view of power requirements.
However, some uncompressed will have huge swings in DB and power.
So doesn't it come down to the dynamics of the recordings that you listen to.
I read a post suggesting that live acoustical recordings can have 20DB peaks.

That seems modest but let's go with it.
In that case, there would be about 20 times average power to peaks.
So, in this case, 3 watts would require 60 watts peak. Still no problem.

I am going with actual SPL, not theory about dynamic swing SPL. Shouldn't we be going with actual if possible?

If we play the entire song and the Max SPL is 108dB from speakers + sub, and only 87dB from 2 speakers, then the amp is required to drive the actual SPL of 84dB -- or let's just say 87dB actual SPL.

60 watts of power would mean the measured SPL is 100dB from 2 speakers in this case. But the actual is 87dB from 2 speakers.

 

[Goliath]

Yeah, going from 125 to 250 WPC would get you 3dB more.

Just going from 125 to 250WPC gains you nothing - if you haven't reached the full rated output of that amplifier and your speakers can output additional SPL without compression then yes, you're going to gain a whopping 3 dB. One could quadruple their amplifier power and the voltage swings would remain the same at the speaker.

 

[RichB]

I am going with actual SPL, not theory about dynamic swing SPL. Shouldn't we be going with actual if possible?

If we play the entire song and the Max SPL is 108dB from speakers + sub, and only 87dB from 2 speakers, then the amp is required to drive the actual SPL of 84dB -- or let's just say 87dB actual SPL.

60 watts of power would mean the measured SPL is 100dB from 2 speakers in this case. But the actual is 87dB from 2 speakers.

Sure but for the purpose of sizing an amp, is a requirements issue.
Running a sub and crossing your speakers works very well and reduces your power requirements.

I was discussing the parameters to size an amp.
Most of the time, I know I am listing to a watt or two.
I am curious though, when I play a dynamic recording in the 80DB range to hear the softer passages, what is a reasonable amount of peak power required to avoid compression.

- Rich

 

[Goliath]

Thanks, I caught that.

It 20 DB peaks a reasonable expectation for well recorded music?
I am sure that amps can produce peaks but depending on the design they cannot sustain it.

- Rich

I think a crest factor of 20 dB represents the extreme end of the dynamic range of recorded music.

 

[Goliath]

Sure but for the purpose of sizing an amp, is a requirements issue.
Running a sub and crossing your speakers works very well and reduces your power requirements.

I was discussing the parameters to size an amp.
Most of the time, I know I am listing to a watt or two.
I am curious though, when I play a dynamic recording in the 80DB range to hear the softer passages, what is a reasonable amount of peak power required to avoid compression.

- Rich

Sorry, not AcuDef... but if your speakers have a reasonable sensitivity (87 dB) and you are seated at a reasonable distance (3 meters) then you probably would need 1W or less once you factor in additional reinforcement from room gain and speakers placed in close proximity to wall boundaries. If you listen at 80 dB average then your peak to average levels could vary as much as 20 dB, or 100 times the power. So if you use 1W on average, then at the extreme end of things, 100W is probably what you'll need for dynamic peaks.

 

[RichB]

Sorry, not AcuDef... but if your speakers have a reasonable sensitivity (87 dB) and you are seated at a reasonable distance (3 meters) then you probably would need 1W or less once you factor in additional reinforcement from room gain and speakers placed in close proximity to wall boundaries. If you listen at 80 dB average then your peak to average levels could vary as much as 20 dB, or 100 times the power. So if you use 1W on average, then at the extreme end of things, 100W is probably what you'll need for dynamic peaks.

My Salons are close to 4 ohms so you probably have to double those numbers.
I do sit 12 feet from my speakers, but there is 20 feet of room in back, 12 foot ceilings and large openings on the left and rear of the room. My guess is I am using the capabilities of my Parasound A51 amp.

- Rich

 

[AcuDefTechGuy]

Sorry, not AcuDef... but if your speakers have a reasonable sensitivity (87 dB) and you are seated at a reasonable distance (3 meters) then you probably would need 1W or less once you factor in additional reinforcement from room gain and speakers placed in close proximity to wall boundaries. If you listen at 80 dB average then your peak to average levels could vary as much as 20 dB, or 100 times the power. So if you use 1W on average, then at the extreme end of things, 100W is probably what you'll need for dynamic peaks.

That's what I don't get. I'm not measuring the average SPL. I am measuring the PEAK SPL. And the Peak SPL is 87dB from 2 speakers.

 

[j_garcia]

3 dB sensitivity gain/loss would be a halving or doubling of amplifier power to maintain the same SPL. It's still not a significant difference. Yes, a doubling of voltage equates to a 6 dB increase, so 3 dB would be 50% of the measured level, but so what? All we care about is perceived volume - you know, what we can or can't hear.

All I was saying is that it IS audible and isn't as small as some like to think. There is no question it can be heard, but I agree with what you are saying because of said previous comments about the perception of a 10dB increase. Where I was going with that is, a lot of people like to just off hand say that you need to double the power (+6dB) to make a big difference in sound, but +3dB is not an insignificant increase in headroom when comparing amp to amp or when comparing sensitivity from speaker to speaker. My old speakers were 91.5dB sensitive and my new ones are about -4dB sensitivity comparatively. Just hooking them up without adjusting levels, there was a significant drop in output.

 

[Goliath]

That's what I don't get. I'm not measuring the average SPL. I am measuring the PEAK SPL. And the Peak SPL is 87dB from 2 speakers.

In my opinion a peak SPL of 87 dB is not ridiculously loud, at least not for me. But you if measure 87 dB peaks, then I think your average level could be anywhere from 6-20 dB below that. Program material can vary so dramatically in level, so I'm really just speculating.

 

[Goliath]

All I was saying is that it IS audible and isn't as small as some like to think. There is no question it can be heard, but I agree with what you are saying because of said previous comments about the perception of a 10dB increase. Where I was going with that is, a lot of people like to just off hand say that you need to double the power (+6dB) to make a big difference in sound, but +3dB is not an insignificant increase in headroom when comparing amp to amp or when comparing sensitivity from speaker to speaker.

I agree that 3 dB is noticeable. I guess I just don't think it's that much of a big deal.

 

[AcuDefTechGuy]

In my opinion a peak SPL of 87 dB is not ridiculously loud, at least not for me. But you if measure 87 dB peaks, then I think your average level could be anywhere from 6-20 dB below that. Program material can vary so dramatically in level, so I'm really just speculating.

Well, the total PEAK SPL from speakers + subs is 108dB, which I think is pretty loud.

Doesn't everyone think 108dB is pretty loud? I hope.

But my point is, when I turn off the subs, the speakers are only 87dB PEAK.

So even when the Total Peak SPL is 108dB, the amp driving the speakers are only driving less than 87dB PEAK.

Next time I need to turn off the speakers to see how loud the subs are by themselves.

 

[AcuDefTechGuy]

I agree that 3 dB is noticeable. I guess I just don't think it's that much of a big deal.

I don't either.

I think power amp is 100 x overrated.

 

[wilejoe]

Thanks for all the help but my head is still swirling . A whole lot of info I'll sit down and digest it when I have a chance . And Rich my cat also loves my music no matter how loud I play it. He can hear a mouse running through the grass and still handle rock and roll. There seems to be a little confusion . The wattage difference between the 2 amps is only 25w (125 compared to 150) and the speakers need to flow through many rooms kitchen, living room, dining room .... I know this isn't the best setup but I'm sure it will sound better then my bose acoustimass 5 little cubes and old $150 Sony 100w receiver.

 

[AcuDefTechGuy]

There seems to be a little confusion . The wattage difference between the 2 amps is only 25w (125 compared to 150)

There will be utterly no difference between 125W & 150W.

But I really think you should just get a good Denon 3313 from Electronics Expo for about $500 and forget the DAC & amp.

IMO, the Denon will sound better for your 2.1 music because it has Audyssey XT Dynamic EQ and the EMO does not.

 

[ImcLoud]

Thats a terrible idea Accudef , not to mention no fun at all.... This is a music system, go back to your movies and eat some popcorn ...

The truth of the matter is there are tons of options, the xda2 with the separate amp is nice, an avr will work {I personally don't like the idea of all that circuitry and additional crap you don't need being in there {but I am jaded from multiple avr's quitting on me after spending thousands of my hard earned dollars..}

Now I read through some of this power stuff that everyone is talking about and it is interesting.. But I can tell you this from my experiences.. If I run my 2.2 system off of my upa2 {125x2} I will clip it, and the sound suffers. When I run the xpa2, NEVER clip it, and you can tell the difference between the two when you push it, the smaller amp is not as clean at elevated levels, just a fact, I can hear it...

I can tell you there is a reason that most amps are between 200-250 watts per channel, it because that seems to be enough, 125-150 is almost enough, 70-90 is not enough, and 200-250 is about perfect, I never clip my 200w per channel amps, while I clipped my avr and I clipped my upa200, while I never clipped my mini X amp or my toppings that are all low power, but that is because I run them in smaller rooms, my minix is powering bookshelfs 11"'s from my face, but in a larger room with a music system, you tend to need a lot more room, and dynamic headroom is cool...

 

[Goliath]

Thats a terrible idea Accudef , not to mention no fun at all.... This is a music system, go back to your movies and eat some popcorn ...

I can tell you there is a reason that most amps are between 200-250 watts per channel, it because that seems to be enough, 125-150 is almost enough, 70-90 is not enough, and 200-250 is about perfect, I never clip my 200w per channel amps, while I clipped my avr and I clipped my upa200, while I never clipped my mini X amp or my toppings that are all low power, but that is because I run them in smaller rooms, my minix is powering bookshelfs 11"'s from my face, but in a larger room with a music system, you tend to need a lot more room, and dynamic headroom is cool...

If you clipped your receiver, as in actually clipped it into gross distortion, then your conditions are most likely atypical - not representative of how most reasonable people use their systems. How much power is "enough" is really dependent on listening habits, for the most part, and since everyone has different listening habits everyone's power requirements will be different, even if every person had the same system!

People also tend to use things like bass management and subwoofers which would significantly reduce the power requirements in their system, so the idea that one needs 200-250 watts in their systems is just absurd. That may apply to one or two people, in certain conditions, but I would argue those conditions are atypical and not reflective of how most people use their systems.

 

[ImcLoud]

I agree to a point, in my 400sq ft room, with 20+ ft ceilings, open the the rest of the house with huge openings and lofts, 125w doesn't do it... and that is with 2- 300watt 12" subs, and crossing the towers at 70hz... With my HT system, it is also a large room, but the ceilings are not as tall and I use an xpa5, I had an avr but 1-it broke down multiple times 2 it ran hot, 3 although it was loud enough, it just didn't have the power...
Just because you have 200w a ch doesnt mean you need to play it loud, think of it this way, the separate amps are built stronger and bigger, they last longer and play louder, not to mention look better{the last one is my opinion of course}, so why not spend the money and have something better and more fun?

The best way to figure out if you need more power is to demo some amps, emo does this for free, get an avr then get an amp and see what you like...
Nothing wrong with starting with one of these DENON DRA-697CI AM/FM Multi-Source/Zone Stereo AV Receiver | Accessories4less adding one of these Amazon.com: MUSE HIFI USB to S/PDIF Converter Decoder Mini USB DAC PCM2704 Black with USB Cable: Electronics and if its not enough power it has preouts so add an xpa2 or a pair of outlaw 2200's, ect... plus you get the zoning options.... and has sub out....

I still prefer xda2 and amps, I am cheap, and I tried the avr and stereo receiver routes, it didn't work for me, I own a r700 like new in its box, but thats where it is, in its box in my basement...

 

[AcuDefTechGuy]

I am jaded from multiple avr's quitting on me after spending thousands of my hard earned dollars.

The only time I've ever been screwed over was when I bought refurbished AVRs. So I understand.

 

[Goliath]

The best way to figure out if you need more power is to demo some amps, emo does this for free, get an avr then get an amp and see what you like...

No offense but that's a very poor method of determining amplifier power. Given the unreliable nature of sighted comparisons one could draw several conclusions that are unrelated to the actual amplifier.

One could misdiagnose the cause of the change in sound due to the gain structure of the amplifier. It could very well be louder at a given setting. You may feel that given the sound is louder it is indicative of higher power and therefore is better. Changes could be related to false positives, not due to the amplifier at all.

Given that sighted comparisons are so chock full of uncontrolled variables it would not seem to be the best test for determining whether that big shiny amplifier actually was responsible for the big sound, and not the other 100 variables that may have been responsible.

If you want to know the voltage at the speaker terminals then perform an actual test like over here :

A Test. How much Voltage (power) do your speakers need? - diyAudio

 

[ImcLoud]

I bought my yammy brand new, it was over $2000 and JUNK, if I never pushed it and listened like a little school girl or my grandmother, then it probably would have lasted for ever but once and a while I like to throw the system on and walk around the house so the volume has to be higher for a few hours, and that was the death sentence for all the avr's I tried, if you want to find some interesting reading google "avr gets hot" or "avr running hot", or "avr quit again" I can go on for ever, there are tons of threads with people dealing with all kinds of problems with avr's.. Which sucks, but they are a part of HT and you can not do much with out a processor or an avr, but with 2 ch music systems, you don't need it, so why burden yourself?

It feels good to have a designated music system, no confusing sh!t storm of buttons, trap doors, microphones, and programming updates, just plug it in, turn it on, and listen to your music... Why complicate something soooo simple, 2 ch music, its EZ leave it alone, integrated amp, pre and amp, or a stereo receiver, don't over think it... Its like needing shorts and buying jeans to cut into shorts.. its like wanting a chair and buying a recliner that you NEVER open up or recline, get it home and take the handle off of it, because you just wanted a chair, its like having a 22" wide lawn and buying a 32" mower.... Im sure one of them will apply...