|
|
Post by Bonzo on Aug 19, 2011 8:33:47 GMT -5
Hello, I'm new here, and don't own any Emotiva gear, YET. But I'm gearing up for it with my upgrade plan (found here) emotivalounge.proboards.com/index.cgi?board=newbie&action=display&thread=19353 I did some searching around on here, even using the search function, and I couldn't find the answer to a few questions about this amp. Part of my plan involves eventually bridging the XPA-2 to drive one one speaker, my center channel, while using 2 XPA-1's to drive the left & rights. My speaker is rated at 8 ohms, so I don't think that's any issue according to the XPA-2 spec sheet and manual. What I was wondering first is, what is the power rating out of the XPA-2 when bridged? From what I've read on other amps over the years, is that they typically double in power when bridged. So are we now talking 600 watts for the XPA-2? Center Channel Speaker
Definitive Technology C/L/R 3000
8 ohm, 91 db sensitivity, rated for 20-400 wattsSecond, does anyone know if this is going to give me any funky issues across the front 3 channels? I'm thinking "no", as long as I do the pre-amp/receiver channel level set up thing correctly to compensate. But, I'm not 100% sure. Third, and this is just something more general, I see a bunch of old type/talk about the XPA-2 being rated at 250wpc, but it's now rated at 300wpc. Was there an upgrade somewhere along the way? Was the initial rating wrong? Can someone fill me in? Thanks for any information you can help me with. Cheers ---- Bonzo  |
|
|
|
Post by razel on Aug 19, 2011 11:25:46 GMT -5
XPA-2 is 1000 watts bridged. Audioholics tested it bridged and came close at 860 watts. Their line voltage dropped, so I'm sure it can output 1k. If fact, I bet if you can run it 220v, your AC wires will allow it to get there easier.
There was no upgrade. It just depends on what distortion you measure it at. 1% distortion ratings which is common with mass market receivers are usually higher than .1%.
Have fun with a bridged XPA-2. That was my next upgrade path. I had XPA-1s which were AMAZING. Too bad my existing RPA-1 is 95% as amazing at 1/4-1/3 of the cost and half the space. My next venture was a pair of bridged XPA-2s, but those upcoming XPR-1s look like killers!
|
|
|
|
Post by srrndhound on Aug 20, 2011 15:54:12 GMT -5
Bonzo, just curious why you want to bridge the amps. The center speaker will not need any more power, and bridging costs you in cutting the damping factor in half because the output impedance is now that of two amps, not one. Might even raise the distortion slightly since amps usually have lower distortion with higher impedance loads.
It will also increase the noise floor as much as 6 dB (assuming the noise is dominated by the preamp output stage).
|
|
|
|
Post by Bonzo on Aug 23, 2011 17:24:03 GMT -5
XPA-2 is 1000 watts bridged. Audioholics tested it bridged and came close at 860 watts. Their line voltage dropped, so I'm sure it can output 1k. If fact, I bet if you can run it 220v, your AC wires will allow it to get there easier. There was no upgrade. It just depends on what distortion you measure it at. 1% distortion ratings which is common with mass market receivers are usually higher than .1%. Have fun with a bridged XPA-2. That was my next upgrade path. I had XPA-1s which were AMAZING. Too bad my existing RPA-1 is 95% as amazing at 1/4-1/3 of the cost and half the space. My next venture was a pair of bridged XPA-2s, but those upcoming XPR-1s look like killers! Yikes!!! 860 watts?  !@#$% I was just looking for a bit more juice, no to power the entire neighborhood. Maybe I should back my plan down a bit. Hmmmmm....... So why wouldn't more people do the bridge thing? Oh wait, I see srrndhound's answer below. Add that you must mate this to an 8 ohm only load, and the XPA-1 becomes more flexible. Thanks for the answer, it's helps me a lot. Cheers! |
|
|
|
Post by Bonzo on Aug 23, 2011 18:02:02 GMT -5
Bonzo, just curious why you want to bridge the amps. The center speaker will not need any more power, and bridging costs you in cutting the damping factor in half because the output impedance is now that of two amps, not one. Might even raise the distortion slightly since amps usually have lower distortion with higher impedance loads. It will also increase the noise floor as much as 6 dB (assuming the noise is dominated by the preamp output stage). srrndhound, From my post in the other thread, my current plan to upgrade in short form went like this; #1. XPA-2 to give me awesome music performance first. Use my receiver to power the center & 4 surrounds (of which I currently only have 2 for 5.1). So I get great music day 1, and I upgrade surround to 7.1. #2. XPA-5 to upgrade the center and 4 surrounds. #3. Lastly, when ready, upgrade the L/R fronts to (2) XPA-1's. With that done, the idea was to bring the center up from 200wpc closer to the 500wpc of the fronts by using the amp I had on hand. But I had no idea I would go from 300 to 860 or even 1000. I was thinking 300 to 600, tops. And then with your added input, maybe it's not such a good idea and why people aren't talking about it much. I'm not an electrical engineer by any means, and when I had a chance to learn the ins and outs in college I hated it at the time (why I'm not sure because now I would like it). So honest input from folks like you helps a lot. I do know things from years and years of reading mags like Home Theater and Sound & Vision, but I don't always understand everything they are discussing either. So thanks for the input. As far as the plan goes, I see other possibilities, some better than others. #1, Since the XPA-2/XPA-5 is supposedly already a wicked combination, just stick with the original plan, but stop after step #2. #2. Buy an XPA-5 first and live with it until I can go up. I can just power the 7.1 rears with my receiver. This gets me over all better performance, just not the super super kick of 300 watts for music. Then, upgrade to 3 XPA-1's across the front when money allows. This would leave the XPA-5 running 4 channels. #3. Now this might be a crazy stupid dumb *bleep* idea, but you tell me. What if instead of bridging the XPA-2, I used it to bi-amp my center? I could use a splitter to send the same center channel signal to both inputs in the XPA-2, then run 1 output to the top terminals and 1 output to the bottom terminals like bi-wiring (my center is actually tri-wirable). Is something like this even advisable? EDIT 7/23 #4. You know, everyone always talks about the power of an amp with all channels driven, which is now 300 for the XPA-2 according to the website. But, what is the power if only one channel is being driven? 350? 400? Maybe my original plan isn't so far off, but I would be leaving a channel unused, which seems like a sin to me. I'm sure there are other plans too, and right now I'm just trying to come up with the best one for us, our money reserves, our furniture space, and other things we are doing. Any way I do this it's a bit of "sell" to the wife, so I need to "show" her the wow difference. We also don't have room or coin right now for buying it all at once, or even buying 2 amps right now, I only have room in my rack for 1. So I'm looking to buy 1, then move up to more later after I've gotten a new rack under a new TV (which we've already picked out from Salamander, not cheap either). Anyway, I'm just plodding on now off on my plan thread, not the bridging thread. Sorry for hi-jacking my own thread. Thanks for you help though, I do appreciate it. Cheers --- Bonzo |
|
NorthStar
Seeker Of Truth
"And it stoned me to my soul" - Van Morrison
Posts: 0
|
Post by NorthStar on Aug 23, 2011 19:12:38 GMT -5
Here's my take: * Loudspeakers with two sets of speaker binding posts (99% of them) are more a novelty for selling than actual audio performance benefit. {The only exception is Active Crossovers used for loudspeakers made specifically with that intended purpose.} * Amplifiers (or A/V Receivers) with Bi-wiring, Bi-Amping, and Bridging facilities, are also more of a novelty than actual audio performance benefit! In all cases you create more harm than good! CONCLUSION: Use ONE channel amp per ONE Loudspeaker. And like I said, the only exception is with Active Crossovers, and Separate Amps (the same amps for the same Gain and same Output Impedance) in a true beneficial way. - Each part of an Audio system requires its own power supply with its own transformer and own crossover. The more you cross that equation, the more you deviate from the true balanced intention. I did not invent this; it has been well documented and experienced. And I know several people who permanently damaged their amplifiers (or receivers) by going over the law of physics! And even damaging their loudspeakers as well by doing so! Audio stress, distortion, overtaxing, etc., are real phenomenons in our electrical power system. And electronics are built mainly to sell, and those features mentioned just above are the making of the devil (useless & destructive features)! I'm just sayin'. ..And I can say much more, but it's sunny outside, and I like to enjoy life fully and in a balanced way!  |
|
|
|
Post by Kidchewie on Aug 23, 2011 21:32:50 GMT -5
Probably not helping here but I'm using four XPA-2s into seven Deftech Mythos Tens and bridging the center channel. I asked Emotiva what the output was bridged and this was their reply:
Thank you for being an Emotiva customer. The XPA-2 puts out roughly 500 watts bridged into 8 ohms. It was not designed to be bridged into 4 ohms so we only give an 8 ohm rating. I hope this helps.
Best Regards,
Emotiva Support
I haven't had a problem but I'm not driving them at reference levels either. I was advised by Chet from Deftech that it would be okay (assuming Emo's information was accurate and I assume it is) as long as I wasn't driving them at reference levels.
However due to the efficiency of the speakers and the power of the amplifiers it is messing up my results with Audyssey during auto-calibration. Therefore I was advised by Chris with Audyssey that I would have to manually adjust Audyssey's results in order to get my speaker levels within range.
I am planning to unbridge my center channel and just leave one channel open on the XPA-2. I thought about using a splitter from the pre/pro to the XPA-2 and getting another center channel (one below and one above the TV) but funds will not allow at this point.
|
|
|
|
Post by srrndhound on Aug 23, 2011 22:14:08 GMT -5
However due to the efficiency of the speakers and the power of the amplifiers it is messing up my results with Audyssey during auto-calibration. It's not the power, but the gain, that is causing the problem for Audyssey. |
|
|
|
Post by Kidchewie on Aug 23, 2011 22:16:02 GMT -5
However due to the efficiency of the speakers and the power of the amplifiers it is messing up my results with Audyssey during auto-calibration. It's not the power, but the gain, that is causing the problem for Audyssey. Yes, thank you that's the word I was looking for. |
|
|
|
Post by srrndhound on Aug 23, 2011 22:25:07 GMT -5
#3. Now this might be a crazy stupid dumb *bleep* idea, but you tell me. What if instead of bridging the XPA-2, I used it to bi-amp my center? I could use a splitter to send the same center channel signal to both inputs in the XPA-2, then run 1 output to the top terminals and 1 output to the bottom terminals like bi-wiring (my center is actually tri-wirable). Is something like this even advisable? It's free, so no harm other that the cost of wires. Don't expect any miracles, though. I know the feeling. I have a 6-ch amp driving 5 speakers (center and 4 surrounds), but it just means the other amps ha a little more juice and a cooler chassis. I agree with using external amps instead of the AVR's, especially for L/C/R. If you are running powered subs, the stress on the main amps (and speakers) is greatly reduced. You might find other ways to use the money than stepping up the power amps again. |
|
|
|
Post by razel on Aug 24, 2011 11:22:52 GMT -5
The XPA 3 and 5 off the website used to have wattage for 1,2,3,5 channels and yes they were higher. Actually here is what was published for the XPA-5 off the web.archive.org/web/20080815023329/http://www.emotiva.com/xpa5.html. 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 I don't know why they removed it, it's great specs that it's more than capable of. |
|
|
|
Post by roadrunner on Aug 24, 2011 12:36:54 GMT -5
Lonnie said that they removed this reporting because some users were interpreting the tables to mean they could abuse the amps by pushing them far beyond their designed usage. Some users were buying an XPA-5, running only one channel, as if it were a 500W mono-block amp. The XPA amps are built very robustly, but not for that extreme misuse.
It is perfectly fine to use just 3 or 4 channels on the XPA-5 and drive them hard. However they discovered some who thought they could use just the one channel and drive it far beyond its designed range and would burn out the output devices. Thus, as usual, the few abusers spoil it for all and Emotiva no longer releases this data.
They also had people bridging the XPA-2 and driving speakers to high volume levels when the speakers where known to presents impedances below 3 Ohms; and then complaining that the amp was going into protect mode. Duh, I wonder why. The Owner's Manual clearly stated to use only 8 Ohm speakers if using the "bridged mode".
|
|
|
|
Post by House on Aug 24, 2011 13:36:51 GMT -5
since i currently have two xpa-2 amps in bridged mode sitting in my bedroom i;ll chime in.....
in all honesty i think you would have to drive your center to rediculous volume levels to notice any kind of distortion....unless of course you just have a pos center. you will get some rediculous headroom out of the amp for your center which in all fairness.....is really overkill! I wont bother with the said wattage output because i think personally watts is the most over rated measure of power there is.....people should really focus more on how much CLEAN juice there system is putting out at a resonable listening volume.....
me bridging my two amps was more for something different to try...honestly...now i cant turn it down quiet enough at night due to the volume contols on my XDA-1 just not being enough cut in signal..........I will say one thing.......my towers do rock the snot out of my room and have yet to hear any noticable distortion out of my speakers.....but keep in mind....im pretty resonable when it comes to volume levels and try to listen responsibly also.
seriously dont be affraid to bridge that amp to your center.....just be ready to have to adjust your signal gains DOWN on your speaker settings in your receiver to match the rest of the system........
I use 8 ohm speakers....and have yet to ever clip my amps into prot. mode at some rediculous volumes when showing some friends the system......
|
|
|
|
Post by ausman on Aug 24, 2011 16:59:16 GMT -5
they likely removed the old stats and revised the totals...
last I checked the xpa-2 is 500 watts x 2 @ 4ohm 1000watts at 4ohms bridged
350watts @ 8 ohms and a bridged capacity of 700watts or there abouts..
xpa-1 is rated at 500 watts @8ohms, 1000 watts @ 4 ohms.
while most of us use 4-8ohm speakers, I wish emo would post stats for 3,2 and 1 ohms loads so if people wanted to use the 1-3ohms speakers they know what they could drive the amps at before protect mode activates..
I don't advocate using a 1-3 ohms speaker though it would be nice to know what the emo amps can do just incase the speakers can dip under 4ohms..
Bonzo looking at the specs of your speakers I would say as long as you don't drive them to hard I would say the xpa-5/xpa-3 would work just fine though as a safety margin I would say go for the xpa-2 to give you a bit of clearance issues..
|
|
stiehl11
Emo VIPs 
Give me available light!
Posts: 7,261
|
Post by stiehl11 on Aug 24, 2011 17:52:10 GMT -5
Really... is there a mouse in your pocket? What speakers do you use, ausman (I haven't asked that question before)? |
|
|
|
Post by Bonzo on Sept 13, 2011 13:15:00 GMT -5
Thanks for all the input everyone. Sorry I've been out of touch for a bit, but still I appreciate the help.
Thanks ---- Bonzo
|
|
!@#$% I was just looking for a bit more juice, no to power the entire neighborhood. Maybe I should back my plan down a bit. Hmmmmm.......
