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Post by sme on Aug 12, 2014 16:08:43 GMT -5
I haven't seen any specific figures on this. Emotiva amps are rated for continuous power with all channels driven. Of course, very few speakers could survive the maximum 200W continuous power provided by the XPA-5, much less the greater power amounts offered up by the more powerful amps. As such, the continuous power capability isn't necessarily as important as the transient/peak power capability. However, many manufacturers publish peak power figures instead of continuous power figures to inflate their numbers versus the competition. I wonder if this is why Emotiva has avoided providing such figures.
I have an XPA-5 amp with 89-92 dB/2.83V/1m speakers (depending on how they are measured), and I sit at about 3 meters away. In theory, at the rated power of 200W (and disregarding the fact that my speakers would likely be cooked by this much power), I can achieve a continuous output of at least 103 dB. Those who point out that 103 dB is an extreme level would be correct in so far as average SPL is concerned. However, I like to collect and listen to music and other sounds with extraordinary dynamic range. For example, one may find music recordings with peaks up to 105 dB when played back at a more appropriate 82-85 dB reference level. With less effort, one may also find film soundtracks with 105 dB peaks when played back at reference level. For a 82-85 dB average playback level, 200W may be total overkill for me, but depending on the transient power capabilities of the amp, those 105 dB peaks could clip.
So let me phrase my question more precisely. Given that a continuous input signal of 1.8V RMS drives the XPA-5 to its rated power into 8 ohm of 200W/channel, what is the highest transient input voltage that the XPA-5 can accept without clipping under the best of circumstances? In other words, if the amp is totally idle and sees a voltage impulse on one of its channels, how many volts can it take without clipping?
My Denon AVR can output slightly more than 4V RMS continuously (peaks of 5.65V) and hard clips above that figure even on transients. That's more than enough for 105 dB peaks, provided that the XPA-5 can accept that kind of voltage momentarily without clipping. Otherwise, I may want to consider a beefier amp some day. So is there a general trend with Emotiva amps in so far as their peak versus continuous output capabilities?
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Post by garbulky on Aug 12, 2014 16:27:26 GMT -5
Not that we know of. The problem with dynamic peaks is what is the standard one measures it at? How long how much distortion is acceptable etc.
I've found that a pre-amp like an XSP-1 or a USP-1 "beefs up" the dynamics vs going direct from the pre-outs to a (large) power amp. You may also want to consider a DAC for better sound quality. All these I think would be more worth it than beefing up the amp I feel.
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Post by garbulky on Aug 12, 2014 16:29:45 GMT -5
It may help you to know that during surround sequences usually very little power is taken up by the surround channels. The unused power is sent to where they are needed (center and front channels). The XPA-5 is able to push out a huge amount of power 2 channels driven - I believe it's close to the XPA-2's figure when only two channels are driven and even more 1 channel driven - was it 800 watts? I can't quite remember. So if your wondering what the real world capabilties are in regular movie watching it's significantly more than what you are thinking.  |
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bootman
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Post by bootman on Aug 12, 2014 16:51:35 GMT -5
Emotiva preamps outputs 4-7 volts depending on model. (the LMC did 7V while the current UMC-200 does 4. No clue what the XMC does) So I think you are overthinking a problem that may not even be there. If you are experiencing clipping then you need more power. However, if you are not clipping then getting a more powerful amp will not gain you anything. But new gear is always fun. ...and you hinted at the real value of peak power. Marketing fluff.  |
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Post by Gary Cook on Aug 12, 2014 17:55:27 GMT -5
FWIW the XPA-5 is rated at 300 watts continuously with 1 channel driven, 275 watts with 2 channels and 200 watts with all 5 channels.
Cheers
Gary
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Post by AudioHTIT on Aug 12, 2014 18:35:04 GMT -5
I think bootman has said it best, you might get a dB or so of headroom out of your amp so not that significant. Either you're clipping or you're not (or as you say your speakers are fried). |
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Lonnie
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Post by Lonnie on Aug 12, 2014 20:22:55 GMT -5
Actually all our amps have a minimum of 3db of headroom with all channels driven.
With only one channel driven I have measured will in excess of the 3db but I don't want to state what it was because I don't want to give people the wrong idea. Keep in mind that with only one channel driven, the full weight of the power supply is available to that one channel, so it has boat loads of headroom.
Lonnie
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Post by garbulky on Aug 12, 2014 21:38:01 GMT -5
FWIW the XPA-5 is rated at 300 watts continuously with 1 channel driven, 275 watts with 2 channels and 200 watts with all 5 channels. Cheers Gary Okay I got the specs from waybackmachine 200 watts RMS/channel into 8 ohms, all channels driven 5 channels - 8 ohm = 200 watts per channel 4 channels - 8 ohm = 230 watts per channel 3 channels - 8 ohm = 250 watts per channel 2 channels - 8 ohm = 275 watts per channel 1 channel - 8 ohm = 300 watts per channel 4 ohm rating: 5 channels - 4 ohm = 350 watts per channel 4 channels - 4 ohm = 375 watts per channel 3 channels - 4 ohm = 400 watts per channel 2 channels - 4 ohm = 450 watts per channel 1 channel - 4 ohms = 500 watts per channel So if those are 4 ohm speaker you get a whopping 450 watts per channel in stereo, 400 watts per channel if its the center and stereo are both driven hard which would be a usual action scene. That's a pretty healthy figure! |
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Post by deltadube on Aug 12, 2014 21:58:34 GMT -5
I haven't seen any specific figures on this. Emotiva amps are rated for continuous power with all channels driven. Of course, very few speakers could survive the maximum 200W continuous power provided by the XPA-5, much less the greater power amounts offered up by the more powerful amps. As such, the continuous power capability isn't necessarily as important as the transient/peak power capability. However, many manufacturers publish peak power figures instead of continuous power figures to inflate their numbers versus the competition. I wonder if this is why Emotiva has avoided providing such figures. I have an XPA-5 amp with 89-92 dB/2.83V/1m speakers (depending on how they are measured), and I sit at about 3 meters away. In theory, at the rated power of 200W (and disregarding the fact that my speakers would likely be cooked by this much power), I can achieve a continuous output of at least 103 dB. Those who point out that 103 dB is an extreme level would be correct in so far as average SPL is concerned. However, I like to collect and listen to music and other sounds with extraordinary dynamic range. For example, one may find music recordings with peaks up to 105 dB when played back at a more appropriate 82-85 dB reference level. With less effort, one may also find film soundtracks with 105 dB peaks when played back at reference level. For a 82-85 dB average playback level, 200W may be total overkill for me, but depending on the transient power capabilities of the amp, those 105 dB peaks could clip. So let me phrase my question more precisely. Given that a continuous input signal of 1.8V RMS drives the XPA-5 to its rated power into 8 ohm of 200W/channel, what is the highest transient input voltage that the XPA-5 can accept without clipping under the best of circumstances? In other words, if the amp is totally idle and sees a voltage impulse on one of its channels, how many volts can it take without clipping? My Denon AVR can output slightly more than 4V RMS continuously (peaks of 5.65V) and hard clips above that figure even on transients. That's more than enough for 105 dB peaks, provided that the XPA-5 can accept that kind of voltage momentarily without clipping. Otherwise, I may want to consider a beefier amp some day. So is there a general trend with Emotiva amps in so far as their peak versus continuous output capabilities? you can never have enough power bro.. join the mono block society with a set of xpa 1s or xpr 1s see novisnick for details cheers.. |
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Post by sme on Aug 13, 2014 1:51:57 GMT -5
Actually all our amps have a minimum of 3db of headroom with all channels driven. With only one channel driven I have measured will in excess of the 3db but I don't want to state what it was because I don't want to give people the wrong idea. Keep in mind that with only one channel driven, the full weight of the power supply is available to that one channel, so it has boat loads of headroom. Lonnie Thank you Lonnie. I am assuming there is some maximum voltage the power supply rails can provide under the best of circumstances. When you say "the full weight of the power supply is available to that one channel", it leads me to conclude that this ultimate maximum voltage must be much higher than is needed to push 200W into 8 ohm. Is that correct? Or may even that information would "give people the wrong idea". I see what you mean, but I think it's unfortunate because in my view, the dynamic power capability is the spec that matters most to HiFi. To other who have asked if I'm currently clipping or not. To tell the truth, I don't know. If I do clip, it's only on the biggest hits that land above 150 Hz or so. In the 300-400 Hz range the Audyssey auto-EQ applies a boost of up to 6 dB (to compensate for a bad reflection that I hope to treat soon) , so I could clip there. The auto-EQ applies similar and even higher boosts above 2 kHz, but I doubt program material gets as hot up there. Either way, my speakers are higher impedance / more efficient in the upper range, so it's mostly a question a whether the power supply rails can provide enough volts as opposed to power. |
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Post by Deleted on Aug 13, 2014 2:09:33 GMT -5
I wouldn't get too hung up on power amp peak power output. The RMS power output specification and test in reviews is a standard measurement done for years and is very legitimate for comparing quality amps, but not how much volume you will realize in your room with your speakers, other than an approximation. Many quality brands of power amps like Emotiva use the demanding all channels operating into 8 and 4 ohms, usually at about 0.1% THD, and their ratings are quite accurate and conservative (not exaggerated). Yes, music and movie sources require extremely short durations of peak dynamic output. Real sources except for test tones almost never produce steady tones that require RMS power. The RMS power is just fine for comparison purposes in a buying decision. It is very difficult to state actual peak power as I don't believe there is an industry wide accepted standard test (someone correct me here if I am wrong). Just know that XPA-5 will provide far in excess of its RMS power output for short periods and even more when most of the power demand in a certain track/selection is in less than all channels (which is most of the time). Sensitivity (efficiency) rating of speaker brands varies in accuracy and that spec is quite often over-stated. Also the lower the frequency being reproduced the more power required, RE your comment above: If I do clip, it's only on the biggest hits that land above 150 Hz or so. (?)
IMO, you won't get more peak power output from amps with similar RMS ratings in any other quality amp brands than you will realize from Emotiva power amps. That said, the amps in AVR's, regardless of their power specs, are not as strong as the RMS or peak output of Emotiva power amps. Trying to in theory predict or even state exact peak power levels thru your speaker in your room is a wasted exercise in futility. There is no AVS AVR's power amp on this planet that will match the RMS/peak power output of the XPA-5 regardless of their stated specs.
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Post by sct on Aug 13, 2014 9:56:52 GMT -5
Chuckster opined: " There is no AVS power amp on this planet that will match the RMS/peak power output of the XPA-5 regardless of their stated specs."
Ummmm, mebbe not, your Chuckness. Take a look at the Sunfire Theater Grand receivers, they are big-boned powerhouses with massive transformers and loads of capacitance: 200 watts/ch. into 8 ohms, all 7 channels driven...
SCT
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geebo
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Post by geebo on Aug 13, 2014 10:23:00 GMT -5
Chuckster opined: " There is no AVS power amp on this planet that will match the RMS/peak power output of the XPA-5 regardless of their stated specs." Ummmm, mebbe not, your Chuckness. Take a look at the Sunfire Theater Grand receivers, they are big-boned powerhouses with massive transformers and loads of capacitance: 200 watts/ch. into 8 ohms, all 7 channels driven... SCT One thing conspicuously missing in the Theater Grand TGR-401 is a 4 ohm power rating. That could be an indication that it just can't deliver the current that the Emo amps are capable of. |
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Post by garbulky on Aug 13, 2014 10:50:13 GMT -5
The TG7201 does 400 W/Ch @ 4 ohms.
However if you look at their ratings, they don't specifically say all channels driven. They say per channel. And for the front they specifically state that it's 200+200.
Also they are rated at a 1 Khz signal. While Emotiva's XPA-5 is rated at full bandwith 20hz to 20khz.
Either way the sunfire amps are pretty nice! Just significantly more expensive.
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geebo
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Post by geebo on Aug 13, 2014 11:06:41 GMT -5
The TG7201 does 400 W/Ch @ 4 ohms. However if you look at their ratings, they don't specifically say all channels driven. They say per channel. And for the front they specifically state that it's 200+200. Also they are rated at a 1 Khz signal. While Emotiva's XPA-5 is rated at full bandwith 20hz to 20khz. Either way the sunfire amps are pretty nice! Just significantly more expensive. Isn't the TG7201 a separate amp? I believe chuckienut meant there is no AVR's power amps that can compete with the XPA-5. Perhaps Chuck will clear that up. |
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Post by sct on Aug 13, 2014 11:16:41 GMT -5
The unit I referenced, Theater Grand, *is* a receiver. Sunfire also made separate amps, the Cinema Grand series...
SCT
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Post by garbulky on Aug 13, 2014 11:57:30 GMT -5
oh ooops.
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Post by Deleted on Aug 13, 2014 12:11:41 GMT -5
The TG7201 does 400 W/Ch @ 4 ohms. However if you look at their ratings, they don't specifically say all channels driven. They say per channel. And for the front they specifically state that it's 200+200. Also they are rated at a 1 Khz signal. While Emotiva's XPA-5 is rated at full bandwith 20hz to 20khz. Either way the sunfire amps are pretty nice! Just significantly more expensive. Isn't the TG7201 a separate amp? I believe chuckienut meant there is no AVR's power amps that can compete with the XPA-5. Perhaps Chuck will clear that up. Error corrected. |
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geebo
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Post by geebo on Aug 13, 2014 12:27:34 GMT -5
The unit I referenced, Theater Grand, *is* a receiver. Sunfire also made separate amps, the Cinema Grand series... SCT I thought you were talking the receiver. So the comment that they do not specify a 4 ohm output could be an indicator that it just can't deliver the current of the XPA-5 which would support chuckienut's statement. |
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Post by Deleted on Aug 13, 2014 12:37:10 GMT -5
Chuckster opined: " There is no AVS power amp on this planet that will match the RMS/peak power output of the XPA-5 regardless of their stated specs." Ummmm, mebbe not, your Chuckness. Take a look at the Sunfire Theater Grand receivers, they are big-boned powerhouses with massive transformers and loads of capacitance: 200 watts/ch. into 8 ohms, all 7 channels driven... SCT Sorry, but that big boned amp in the light weight Sunfire Grand (32lbs) is spec'd at (Front: 200 W + 200 W, 8 ohms, 1 kHz, < 0.5 % THD ----- no 4 ohms or all channel driven here), That is a far cry from the ACD (all channels driven at 4ohms --- 300 watts RMS @ 4 ohm (0.1% THD) output of the XPA-5 (73lbs). No offense to any AVR, but they are not separate power amps, simply no contest. |
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