The advantage of a 250wpc Amp vs a 125WPC is?

[TKYR67]

I didn't make a post about it, but I am now an owner of a natural pair of Sierra-1s. The ACI Sapphire XL is truly an amazing speaker but I am a "more BANG for the BUCK" kind of guy and the Sierra-1 got me pretty much there at half the price. Don't get me wrong, if money was no object I would own the Sapphire XL but in this economy money matters. If I can get amazing sound reproduction and keep some money in my pocket at the same time, it's not hard to decide which way to go.

Now to my question, I am using an Emotiva UPA-2 which is rated at 125wpc and people keep telling me that the XPA-2 (250wpc) would drive them better.

I understand why too little power is a bad thing, but what would be the advantage to having more power? The Sierras are not hard to drive at all.......



Oh, and about that Affordable Audio shoot out which lead to me buying the Swan D2.1SE. After being an owner of both, I prefer the Sierra-1. MUCH better midrange, and I prefer the top end of the Sierra-1. Not to mention I still get my big bass but it is considerably more controlled.

[Mag_Neato]

If you are running the Sierras full range, then more power will help keep things under control more as the volume increases. Also, it will allow dynamics to expand further with less compression. You will not see a big increase in overall loudness, as that requires factors of more power. With a sub taking the burden of the bass off the amp, you will not hear as large a difference, but it can still open up dynamics. Curtis runs 500 watts to his Sierras and I'm sure he will chime in here.

[rogerm]

"Now to my question, I am using an Emotiva UPA-2 which is rated at 125wpc and people keep telling me that the XPA-2 (250wpc) would drive them better."

I have the Sierra's L/C/R and I'm using the Emotiva XPA-3 to drive them. I also have the UPA-2 running my rear speakers. An Onkyo 705 serves as the Pre/Pro. When I listen to music, I listen in two channel, no sub. The XPA-3 delivers 200 wpc. I have had the UPA-2 running them and to be honest I can't perceive any difference in sound quality at my listening levels and once in awhile I listen quite loud. the 125 wpc UPA-2 never runs out of room and is nowhere near pushing hard. You are getting a true 125 wpc with them. I've even had them running my Magnepan 2.5R's which are very inefficient and it drives their 4 ohm load with no effort. The 2 is providing 185 wpc to the 4 ohm load. My room is 1800 cf with an opening to another room the same size. The guys on the Emo Forum love the power and I do too. I just think that at some point you hit diminishing returns. If I had a two channel system the UPA-2 would have been plenty and the UPA-7 would have done the trick in my home theater setup.

[TKYR67]

Thanks guys for the quick replies. It seems to me that this UPA-2 is getting the job done nicely without even working hard and any more power would just be overkill. I can put the $600 difference towards a DAC.

[curtis]

The differences will be with the dynamics at louder levels.....if you push them hard enough. Every doubling of amplifier power (ie. 125w to 250w) is 3db of headroom.

[jvillas]

I would have to agree with all the comments above. There are some Sierra owners running tube amplifiers of modest power with excellent results. I assume this is for 2 channel.
Thread
http://forum.ascendacoustics.com/showthread.php?t=3245

[scape]

If you are running the Sierras full range, then more power will help keep things under control more as the volume increases. Also, it will allow dynamics to expand further with less compression.

is this also called clipping? I've heard of people calling it compression, just want to make sure I understand you is all :D

[scape]

I can put the $600 difference towards a DAC.
what kind of music files are you listening to?

[GirgleMirt]

Nice to hear about Sierra vs ACI! :D


I can put the $600 difference towards a DAC.


I am a "more BANG for the BUCK" kind of guy ... If I can get amazing sound reproduction and keep some money in my pocket at the same time, it's not hard to decide which way to go.

Does not compute. Which are you really? Someone who puts 600$ on a DAC, or someone who's more of a bang for the buck kinda guy? :) You must choose!

[Mag_Neato]

is this also called clipping? I've heard of people calling it compression, just want to make sure I understand you is all :D

I would not call it clipping. Clipping is when the output waveform clips at the peaks, sending out tweeter-destroying distortion. I am talking about dynamic headroom in the form of power reserves. That is what allows the loud dynamics to "bloom", or explode so to speak. More of an effortless sound. compare it to listening to AM radio, then switching to the same thing in FM. The AM version is a bit flatter sounding with no dynamics. A bit extreme, but the only thing I could come up with to describe it. Or take two cars accelarating at highway speed. A four cylinder will get you passing other cars going slower, where as a Hemi Charger will pin you to your seat!

[wish]

I recently purchased 3 Sierra-1's (LCR) and have been tinkering with the idea of an amp. I'm currently driving them with a Yamaha 863 with provides 105watts/ch (RMS Output Power (20Hz - 20kHz) 105W x 7). Given the above my gut is telling me I won't be seeing much difference if I get the UPA-2 since it only gives 20 more watts/ch. The question I suppose is how much of the Yamaha power rating is "true" 105 watts. Even if it were less would it really be so much so as to hear a difference with an amp?

Also, I typically don't have the opportunity to really push the volume (wife and 5yo). I suspect to see any real tangible difference I'd have to move to the XPA-2 at 300 watts/ch (which at $800 is out of my price range).

[Robert7]

I purchased a Nad C 272 which is a 2 (150 watts per) channel amp with a Harman Kardon avr 435 and Sierras across the front and it sounds pretty good. Significantly more dynamic with the added amp to my ears. And I can go up to about 95 to 97 dB when I am in the mood without obvious distortion.

[drewface]

i added an external amp (XPA-5) to my yamaha receiver a while ago, and while not a huge improvement to the overall sound, i did notice the real low end frequencies had a little more presence and sounded "tighter" (less muddy on quick moving bass, like double-bass pedal rolls, if you're familiar with metal). also, the high end frequencies seem less harsh. i don't know if this was a result of the amp or some other change i made at some point prior to the addition, but i didn't really notice it until afterwards.

edit: one thing to note, i (think i) noticed these changes on my 340SEs, which are more efficient than the sierras, and probably were affected less than sierras would be.