|
Post by Jim on Mar 13, 2013 19:43:46 GMT -5
wow im confused how or why do they say 250 wpc at 8 if it really is 360 at 8.. It's just a technical matter of the rated distortion at any given wattage. They could probably even do more than 360 watts... just with higher distortion. The rated wattage isn't necessarily the max output. But yeah, listen to your speakers. If they sound unhappy, you're probably cranking it too loud (either for the amp or the speakers).
|
|
|
Post by Dan Laufman on Mar 13, 2013 21:28:24 GMT -5
It's clipping that kills speakers, not clean power.
The more power, the better! ;D
|
|
|
Post by deltadube on Mar 13, 2013 21:39:55 GMT -5
well to be a bit more clear paradigm recommend or suggest
amp power 15 watts up to 350 watts for the studio 100s but not to imput more than 230 watts does not say at what ohm. but i assume 8 since they say its an 8 ohm speaker.. but im sure it dips to low 4s at times..
i do understand under power vs over powering your speaks which paradigm also recommends but to be careful.. i guess you have to do it slowly.. and listen .. wish i knew when i was hitting 225 watts..
i got my xpa 3 wow very happy with it.. scared to turn it up.. think i might run out of power .. i have my limiter set to -10 db.. one day like to try -9 or -8 but its only 200 watts so how do you know when u run out of power.. speakers could burn out quick..
its pretty loud at -10 i like it sometimes.. couch is vibrating like crzy feels good LOL.. but being addictive personality i like MORE..
cheers..
|
|
|
Post by garbulky on Mar 13, 2013 22:48:10 GMT -5
When your ears give out, then you are using 200 watts.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 13, 2013 23:12:33 GMT -5
..... the XPA-1L in Class A mode will run toastier than either itself in Class A/B mode or the XPA-1. You shouldn't worry about it; but do be sure to give it a bit of room to breathe. Did anyone else noticed that Keith made an apparent non-intentional slip of the tongue fingers here when typing his post. Notice how the term toastier subconsciously entered into the text of the post. This IMO is a Freudian slip, a very obvious parapraxis! This mistaken slip and use of the word toastier, I presume supposedly is the presence of restrained or repressed impulses, an anxiety type release of hidden emotion on the part of Keith. My secret source at Jade Design Headquarters mentioned that Keith has been burning the midnight oil feverishly working on getting the New Emotiva X-Toaster prototype ready for production, so that it might be the highlight surprise of the next Emotiva Podcast. I'm certain that I have caught on to something hot here folks. Don't miss the next Emo Podcast!
|
|
KeithL
Administrator
Posts: 9,945
|
Post by KeithL on Mar 13, 2013 23:48:26 GMT -5
Try not to worry so much about those numbers In general, speakers "burn out" when you overheat the voice coil. When you feed it too much power, the voice coil overheats over time and eventually melts. If you run the amplifier into pure clipping, then an "unnatural" amount of energy will go to the tweeter, and it will eventually burn out. Those numbers are GENERAL, LONG TERM GUIDELINES. Their recommendation of 230 watts as a maximum does not mean that your speaker will burn out if you send it 231 watts. It means that, if you send it a lot more, for a long time, eventually the speaker will be damaged. I would also advise AGAINST using a limiter. The limiter will indeed limit the maximum power, but it will generally not limit the average power. If you continue to turn things up after you are "in limit", the average power will rise even though the peaks are limited. You will feel safer, but will actually be at greater risk of damaging your speakers. Simply avoid turning things up until they distort and you should be fine. You know you've run out of power when you hear distortion. If you're running things so loud you can't tell if they're distorting then you are definitely risking damage to your speakers and/or your ears (and you can't buy new ears). [If you want your couch to vibrate, then you need a big sub, or one of those "ButtKicker" things that clamps to your couch and shakes it to the music ] well to be a bit more clear paradigm recommend or suggest amp power 15 watts up to 350 watts for the studio 100s but not to imput more than 230 watts does not say at what ohm. but i assume 8 since they say its an 8 ohm speaker.. but im sure it dips to low 4s at times.. i do understand under power vs over powering your speaks which paradigm also recommends but to be careful.. i guess you have to do it slowly.. and listen .. wish i knew when i was hitting 225 watts.. i got my xpa 3 wow very happy with it.. scared to turn it up.. think i might run out of power .. i have my limiter set to -10 db.. one day like to try -9 or -8 but its only 200 watts so how do you know when u run out of power.. speakers could burn out quick.. its pretty loud at -10 i like it sometimes.. couch is vibrating like crzy feels good LOL.. but being addictive personality i like MORE.. cheers..
|
|
|
Post by milt99 on Mar 13, 2013 23:57:44 GMT -5
EDIT: Oops it took me so long to type in my post that KeithL already responded
deltadube, it's like Dan and I said. When an amp is over-driven, i.e., turned up so loud that the amp cannot deliver any more watts and amps at a given ohm, the amp will "clip", meaning that the amp will try to go louder but will output a highly distorted signal at a frequency that causes the speaker cone and voice coil to move in an extremely fast non-piston-like manner which fries or welds the voice coil to the magnet OR if severely over-driven like with a severe transient in the music can cause the cone into over-excursion where it tries to reproduce the loud SPL but is driven forward to the limit of the surround that holds the cone to the basket and makes a horrible flapping noise. This can cause the surround to rip and/or cause the voice coil to permanently come out of the perfect alignment with the pole of the magnet or warp the voice coil. In either case when you push on the cone you will feel the voice coil rubbing against the magnet. Finito! Over excursion is more common in subwoofers. You're worrying too much about this, trust me. Your system will tell you when things aren't kosher by sounding really sh!tty and well, distorted. The ohm ratings of your speakers are a "nominal" rating which is kind of like an average over the entire frequency range. Any decent review of your speakers will have a graph of the ohm number over the freq. range and\or mention what it is in more detail.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 14, 2013 0:03:05 GMT -5
Does the test data show that this is actually a 362.3W amp? Into 8 ohm. yep ;D Shhhhh........don't tell anyone we under rated the amp. Sorry Lonnie, not to bring up a dead horse, but I'm still confused. Why is the power output at 8 ohms 363.2 watts with 0.371686 %. Why not at the common level of 0.1% THD for the AP test? I'm of course not familiar with the operation of the AP, but my question would be why 0.371686? I would presume one could set the THD level first and then see what the power output is at that level or visa versa (is my thinking here incorrect)? Sorry, of course I might be way off in my presumption here and please Lonnie or Keith explain why we don't use a consistent THD level for all XPA amps not only in the published specs but also with the AP test. For example, the 8 ohm output on the XPA-1 of 500.5 watts is at 0.003260%. Are these perhaps misprints? XPA-1L 363.2 watts into 8 ohms @ 0.371686 % XPA-1 500.5 watts into 8 ohms @ 0.003260 % In other words, the published spec on the XPA-1l is 250 watts @ 8 ohm (0.1% THD). So why don't we use the AP to see what the actual THD is at 250 watts output or see what the actual power output is at 0.1% THD?
|
|
|
Post by cwt on Mar 14, 2013 0:17:59 GMT -5
I'm certain that I have caught on to something hot here folks. Don't miss the next Emo Podcast! Mmm dual monoblock toast ;tasty ;D
|
|
KeithL
Administrator
Posts: 9,945
|
Post by KeithL on Mar 14, 2013 0:45:26 GMT -5
Power specifications are LIMITS. When we publish a spec, it is a general statement about the minimum performance you can expect from any unit of that model. So, when we say 250 watts @ 8 ohms @ 0.1% THD, we're saying that any XPA-1L you test will produce more power at less distortion than that. (All production units can be expected to test very much the same as each other.) The AP can be programmed to format its results in lots of different ways. We could have asked it to give us the maximum power before the distortion hit 0.1%, or we could have told it to give us the distortion at 250 watts, or both. We could also have had it run the graph up to a very high distortion point, then "read" the power output from that one graph at different levels of distortion. As you'll notice, we usually DO set the AP reports to run at "rated power". We just wanted to show off a bit this time and show everyone how conservatively we rated the XPA-1L, so we set the AP to let the test run up to levels way beyond rated power - so we could show off that it's that much better than the spec. Where the actual number comes from is easy.... if you look at the distortion curve a few pages later, considering the amount of detail you can see on the graph, you can see that the XPA-1L "stays below about 0.5% distortion up to somewhere just over 350 watts". When we decided we wanted to show off, the operator was told to have the AP check the distortion at a point somewhere close to where that maximum level was. It turns out that the closest round number was 1.810 V of input level, which, due to the gain of the XPA-1L, just happened to work out to that odd number. If we'd really wanted to we could indeed have given the exact power level when the XPA-1L hit 0.5% THD, or the exact THD at 350 watts, but that's not what we did...... If you like, you could say that the specified power is 250 watts, and the graph is just showing off. yep ;D Shhhhh........don't tell anyone we under rated the amp. Sorry Lonnie, not to bring up a dead horse, but I'm still confused. Why is the power output at 8 ohms 363.2 watts with 0.371686 %. Why not at the common level of 0.1% THD for the AP test? I'm of course not familiar with the operation of the AP, but my question would be why 0.371686? I would presume one could set the THD level first and then see what the power output is at that level or visa versa (is my thinking here incorrect)? Sorry, of course I might be way off in my presumption here and please Lonnie or Keith explain why we don't use a consistent THD level for all XPA amps not only in the published specs but also with the AP test. For example, the 8 ohm output on the XPA-1 of 500.5 watts is at 0.003260%. Are these perhaps misprints? XPA-1L 363.2 watts into 8 ohms @ 0.371686 % XPA-1 500.5 watts into 8 ohms @ 0.003260 % In other words, the published spec on the XPA-1l is 250 watts @ 8 ohm (0.1% THD). So why don't we use the AP to see what the actual THD is at 250 watts output or see what the actual power output is at 0.1% THD?
|
|
|
Post by deltadube on Mar 14, 2013 0:46:09 GMT -5
Try not to worry so much about those numbers In general, speakers "burn out" when you overheat the voice coil. When you feed it too much power, the voice coil overheats over time and eventually melts. If you run the amplifier into pure clipping, then an "unnatural" amount of energy will go to the tweeter, and it will eventually burn out. Those numbers are GENERAL, LONG TERM GUIDELINES. Their recommendation of 230 watts as a maximum does not mean that your speaker will burn out if you send it 231 watts. It means that, if you send it a lot more, for a long time, eventually the speaker will be damaged. I would also advise AGAINST using a limiter. The limiter will indeed limit the maximum power, but it will generally not limit the average power. If you continue to turn things up after you are "in limit", the average power will rise even though the peaks are limited. You will feel safer, but will actually be at greater risk of damaging your speakers. Simply avoid turning things up until they distort and you should be fine. You know you've run out of power when you hear distortion. If you're running things so loud you can't tell if they're distorting then you are definitely risking damage to your speakers and/or your ears (and you can't buy new ears). [If you want your couch to vibrate, then you need a big sub, or one of those "ButtKicker" things that clamps to your couch and shakes it to the music ] well to be a bit more clear paradigm recommend or suggest amp power 15 watts up to 350 watts for the studio 100s but not to imput more than 230 watts does not say at what ohm. but i assume 8 since they say its an 8 ohm speaker.. but im sure it dips to low 4s at times.. i do understand under power vs over powering your speaks which paradigm also recommends but to be careful.. i guess you have to do it slowly.. and listen .. wish i knew when i was hitting 225 watts.. i got my xpa 3 wow very happy with it.. scared to turn it up.. think i might run out of power .. i have my limiter set to -10 db.. one day like to try -9 or -8 but its only 200 watts so how do you know when u run out of power.. speakers could burn out quick.. its pretty loud at -10 i like it sometimes.. couch is vibrating like crzy feels good LOL.. but being addictive personality i like MORE.. cheers.. thanks .. i had no idea a limiter does that.. with the limiter at -10db i can say it sounds great no sign of distrotion when i turn it up to say -10.5db.. its sounds good and loud.. for a good tune.. i have accidentally hit the volume button and it goes up pretty fast .. so that limiter saved me from being 0 in a few sec so i should take it off then is what your saying right? if i hooked up a xpa 1 vs xpa 3 would it be this loud sooner like -20db on the scale with the more power? thanks for you time
|
|
|
Post by deltadube on Mar 14, 2013 0:49:10 GMT -5
I'm certain that I have caught on to something hot here folks. Don't miss the next Emo Podcast! Mmm dual monoblock toast ;tasty ;D with 2kw on the scale does it need a dedicated 20 amp circuit i like it! cheers.
|
|
KeithL
Administrator
Posts: 9,945
|
Post by KeithL on Mar 14, 2013 1:06:05 GMT -5
What a standard limiter does is to turn down the parts that get too loud. Since, with music, since it's the peaks that get loud first, the limiter turns them down but leaves the average parts alone (another word for limiter is "compressor"). Used in moderation, it may prevent the peaks from clipping, and limited peaks sound better than clipped peaks - but undistorted peaks are better yet. The hazard is that, since the peaks don't distort, it encourages you to turn up everything because it doesn't sound clipped. Limiters are extensively used for radio broadcasts (that's why commercials are louder than most shows, yet they don't clip - because they are MORE limited or compressed). If you want the best sound you want to get rid of the limiter, make sure your amp is powerful enough to play without clipping on the peaks, and simply avoid turning it up past where it starts to distort. [Alternately, if it's a good quality limiter, you can keep it as a safety stop, but set it so that it NEVER limits unless you accidentally turn something up too loud. Most good limiters have lights that tell you when they are limiting. Those lights should be off in normal listening, and should ONLY go on if you accidentally turn something up too high - at which point you should turn whatever it was down until the limit lights stop lighting again. If you set things so that the limiter comes on only when the amp would have clipped anyway, then it will serve as a safety net without damaging the sound (this is assuming it has good audio quality otherwise). I would also test it in and out of circuit to make sure that the limiter doesn't introduce other distortion or noise - some do, some don't.] Try not to worry so much about those numbers In general, speakers "burn out" when you overheat the voice coil. When you feed it too much power, the voice coil overheats over time and eventually melts. If you run the amplifier into pure clipping, then an "unnatural" amount of energy will go to the tweeter, and it will eventually burn out. Those numbers are GENERAL, LONG TERM GUIDELINES. Their recommendation of 230 watts as a maximum does not mean that your speaker will burn out if you send it 231 watts. It means that, if you send it a lot more, for a long time, eventually the speaker will be damaged. I would also advise AGAINST using a limiter. The limiter will indeed limit the maximum power, but it will generally not limit the average power. If you continue to turn things up after you are "in limit", the average power will rise even though the peaks are limited. You will feel safer, but will actually be at greater risk of damaging your speakers. Simply avoid turning things up until they distort and you should be fine. You know you've run out of power when you hear distortion. If you're running things so loud you can't tell if they're distorting then you are definitely risking damage to your speakers and/or your ears (and you can't buy new ears). [If you want your couch to vibrate, then you need a big sub, or one of those "ButtKicker" things that clamps to your couch and shakes it to the music ] thanks .. i had no idea a limiter does that.. with the limiter at -10db i can say it sounds great no sign of distrotion when i turn it up to say -10.5db.. its sounds good and loud.. for a good tune.. i have accidentally hit the volume button and it goes up pretty fast .. so that limiter saved me from being 0 in a few sec so i should take it off then is what your saying right? if i hooked up a xpa 1 vs xpa 3 would it be this loud sooner like -20db on the scale with the more power? thanks for you time
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 14, 2013 3:03:24 GMT -5
..... We could have asked it to give us the maximum power before the distortion hit 0.1% ..... As you'll notice, we usually DO set the AP reports to run at "rated power". ..... We just wanted to show off a bit this time and show everyone how conservatively we rated the XPA-1L, ..... so we set the AP to let the test run up to levels way beyond rated power - so we could show off that it's that much better than the spec...... Chuckienut: Sorry Lonnie, not to bring up a dead horse, but I'm still confused. Why is the power output at 8 ohms 363.2 watts with 0.371686 %. Why not at the common level of 0.1% THD for the AP test? I'm of course not familiar with the operation of the AP, but my question would be why 0.371686? I would presume one could set the THD level first and then see what the power output is at that level or visa versa (is my thinking here incorrect)? Sorry, of course I might be way off in my presumption here and please Lonnie or Keith explain why we don't use a consistent THD level for all XPA amps not only in the published specs but also with the AP test. For example, the 8 ohm output on the XPA-1 of 500.5 watts is at 0.003260%. Are these perhaps misprints? XPA-1L 363.2 watts into 8 ohms @ 0.371686 % XPA-1 500.5 watts into 8 ohms @ 0.003260 % In other words, the published spec on the XPA-1l is 250 watts @ 8 ohm (0.1% THD). So why don't we use the AP to see what the actual THD is at 250 watts output or see what the actual power output is at 0.1% THD? Thanks much Keith. I am very familiar with power specs. I just was not sure how the AP could be programed. I think lots of folks are confused when they see different THD figures used in the spec sheet from those on the AP results (many of them don't actually notice the difference). Folks reading this thread will think that the XPA-1L that they know is rated at 250 watts actually tested out at 363 watts, but that's not on a level playing field. Many folks like me know the published spec is usually low and we go to the AP test to see the actual results. If we see the THD has been boosted up by a factor of 3.7X, then we have to checkout the graph to estimate the actual figure. As you say " We could have asked it to give us the maximum power before the distortion hit 0.1%" I think that would have been much more relatively fair and accurate. I looked at the graph and it looks like about 285 watts or so at 0.1%THD which is still makes 250 watts very conservative. " We just wanted to show off a bit this time and show everyone how conservatively we rated the XPA-1L, so we set the AP to let the test run up to levels way beyond rated power - so we could show off that it's that much better than the spec." Well, it is much better than spec but not 363 watts because that was at a higher THD. You also mentioned that " As you'll notice, we usually DO set the AP reports to run at rated power," Take a look at the XPA-1, rated at 0.1% and tested at 0.003260%. It sure would seem more consistent if all XPA amps were rated and AP tested at 0.1% THD. I'm picky about a number of things including price/performance and that is one of the reasons I buy and promote Emotiva. I'm also picky about specs and think they should be consistant. ;D
|
|
|
Post by garbulky on Mar 14, 2013 4:27:57 GMT -5
It took me some time to understand what a limiter was. But if Keith is anything t ogo by, it sounds like dynamic range compression which reduces the peaks - also known as night time mode. You don't want that delta. It compresses the dynamics and liveliness of the music.
|
|
|
Post by ocezam on Mar 14, 2013 7:53:58 GMT -5
I am very familiar with power specs. I just was not sure how the AP could be programed. I think lots of folks are confused when they see different THD figures used in the spec sheet from those on the AP results (many of them don't actually notice the difference). If we see the THD has been boosted up by a factor of 3.7X, then we have to checkout the graph to estimate the actual figure. Chuckienut, The number you're quoting is listed as THD+N Ratio. While I am well aware of what THD is, could you enlighten me about N Ratio? Thanks ...
|
|
KeithL
Administrator
Posts: 9,945
|
Post by KeithL on Mar 14, 2013 9:16:23 GMT -5
THD+N means "total harmonic distortion plus noise". The standard way to measure total harmonic distortion is to send a very clean test signal to the amplifier, take back the output signal FROM the amplifier, scale that down to the same level as the original test signal, and subtract the original test signal from that. What you have left after the subtraction is everything that changed on the way through the amplifier. Since there's no way, with this test, to actually sort out the distortion from the residual noise, the result is THD+N. (Obviously, the distortion by itself is always LESS than this.) (The reason why these graphs usually go UP towards very low power levels is that virtually all amps have a very low but steady "residual noise". So, as the total power, and the total distortion, go down at very low levels, the noise makes up PROPORTIONALLY more of the error signal. This artificially makes the graph go up at very low power levels since the signal and distortion go down but the noise does not. In fact, the actual distortion of a well-designed amp, like ours, actually continues to drop until very close to zero output - it's just hard to separate the distortion from the residual noise - because it is so low.) At any given point, THD+N is a PERCENTAGE OF THE TOTAL SIGNAL. Noise (S/N) is always rated RELATIVE to something and is a RATIO. It can be referenced to full power, or to 1 watt. Since, with most amps, the noise will be relatively constant, the ratio will change as you change what you're comparing it to. You can mathematically derive one from the other (what it should be), but the real measurements are sometimes slightly different. We measure both. If you have two amps sitting next to each other, playing at the same level, comparing the S/N of each referenced to 1 watt for each will give you a direct comparison of how loud the hiss will be on each. I am very familiar with power specs. I just was not sure how the AP could be programed. I think lots of folks are confused when they see different THD figures used in the spec sheet from those on the AP results (many of them don't actually notice the difference). If we see the THD has been boosted up by a factor of 3.7X, then we have to checkout the graph to estimate the actual figure. Chuckienut, The number you're quoting is listed as THD+N Ratio. While I am well aware of what THD is, could you enlighten me about N Ratio? Thanks ...
|
|
KeithL
Administrator
Posts: 9,945
|
Post by KeithL on Mar 14, 2013 10:47:59 GMT -5
Awwwwww, c'mon..... You can't really be complaining because the XPA-1L delivers a lot MORE power than it was rated for ;D Forget the numbers and listen to the music already ..... We could have asked it to give us the maximum power before the distortion hit 0.1% ..... As you'll notice, we usually DO set the AP reports to run at "rated power". ..... We just wanted to show off a bit this time and show everyone how conservatively we rated the XPA-1L, ..... so we set the AP to let the test run up to levels way beyond rated power - so we could show off that it's that much better than the spec...... Chuckienut: Sorry Lonnie, not to bring up a dead horse, but I'm still confused. Why is the power output at 8 ohms 363.2 watts with 0.371686 %. Why not at the common level of 0.1% THD for the AP test? I'm of course not familiar with the operation of the AP, but my question would be why 0.371686? I would presume one could set the THD level first and then see what the power output is at that level or visa versa (is my thinking here incorrect)? Sorry, of course I might be way off in my presumption here and please Lonnie or Keith explain why we don't use a consistent THD level for all XPA amps not only in the published specs but also with the AP test. For example, the 8 ohm output on the XPA-1 of 500.5 watts is at 0.003260%. Are these perhaps misprints? XPA-1L 363.2 watts into 8 ohms @ 0.371686 % XPA-1 500.5 watts into 8 ohms @ 0.003260 % In other words, the published spec on the XPA-1l is 250 watts @ 8 ohm (0.1% THD). So why don't we use the AP to see what the actual THD is at 250 watts output or see what the actual power output is at 0.1% THD? Thanks much Keith. I am very familiar with power specs. I just was not sure how the AP could be programed. I think lots of folks are confused when they see different THD figures used in the spec sheet from those on the AP results (many of them don't actually notice the difference). Folks reading this thread will think that the XPA-1L that they know is rated at 250 watts actually tested out at 363 watts, but that's not on a level playing field. Many folks like me know the published spec is usually low and we go to the AP test to see the actual results. If we see the THD has been boosted up by a factor of 3.7X, then we have to checkout the graph to estimate the actual figure. As you say " We could have asked it to give us the maximum power before the distortion hit 0.1%" I think that would have been much more relatively fair and accurate. I looked at the graph and it looks like about 285 watts or so at 0.1%THD which is still makes 250 watts very conservative. " We just wanted to show off a bit this time and show everyone how conservatively we rated the XPA-1L, so we set the AP to let the test run up to levels way beyond rated power - so we could show off that it's that much better than the spec." Well, it is much better than spec but not 363 watts because that was at a higher THD. You also mentioned that " As you'll notice, we usually DO set the AP reports to run at rated power," Take a look at the XPA-1, rated at 0.1% and tested at 0.003260%. It sure would seem more consistent if all XPA amps were rated and AP tested at 0.1% THD. I'm picky about a number of things including price/performance and that is one of the reasons I buy and promote Emotiva. I'm also picky about specs and think they should be consistant. ;D
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 14, 2013 10:50:01 GMT -5
People love to complain on here
|
|
|
Post by Jim on Mar 14, 2013 11:00:00 GMT -5
People love to complain on here Maybe we'll have something more to do when they start arriving...... Like some actual reviews.. So far we've hit SNR....THD...wattage..distortion..... venting.... What's left? Some really great informative posts about SNR, THD, etc, however. Thanks Keith and company.
|
|