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Post by Hughes, G D on Nov 12, 2017 6:37:29 GMT -5
When I bought the XPA-5 it was with the intent to bi-amp my Paradigm Studio 100 v.2 front mains which worked out very well. With the Onkyo set up for Front High using two of the Sherbourn amps, the surrounds using two and the back surrounds using two, it only made sense to match the remaining single amp in the XPA-5 for the center channel bi-wired.
So, when the Onkyo died I got excited at the thought of buying the XMC-1 (which was not ready when I needed to buy and the only reason I bought the Onkyo) Anyway, Now with the Front High removed, this opens up the chance to Bi-Amp the center but before I do, I need to order some wire and make my cables. Meanwhile, upon setting up the XMC-1, I went ahead and plugged the center into the Sherbourn and ran Dirac for the first time.
Now, I was to totally surprised to find the center channel from the Sherbourn several db louder, maybe a full octave louder than from the XPA-5 which is driving the main stereo pair. Now, it's easy to trim that back but, it makes me question my intent. Am I better off putting the bi-amped fronts with the bi-amped center all on the Sherbourn and using the XPA-5 for the four surrounds? Or, am I over thinking it?
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Post by AudioHTIT on Nov 12, 2017 11:04:55 GMT -5
Logically (and sonically) to me, using the same amp/sensitivity/voicing for the L/C/R and the other amp for the surround channels makes the most sense. It sounds like you have a G2 XPA-5 with 29dB gain and the Sherbourn has 32dB? This isn't a big deal and just requires you to trim them to the proper levels, I just like the idea of making the fronts as seamless as possible.
BTW, 'octave' is not a term which defines loudness, amplitude, or volume; octave refers to pitch and frequency. A note that is one octave higher than another has a frequency twice as high, a note an octave lower has a frequency 1/2 of the other.
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Post by Hughes, G D on Nov 12, 2017 21:15:46 GMT -5
BTW, 'octave' is not a term which defines loudness, amplitude, or volume; octave refers to pitch and frequency. A note that is one octave higher than another has a frequency twice as high, a note an octave lower has a frequency 1/2 of the other. I stand corrected. Tks. |
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Post by pknaz on Nov 13, 2017 3:22:39 GMT -5
What’s the purpose of bi-ampung?
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KeithL
Administrator 
Posts: 9,945
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Post by KeithL on Nov 13, 2017 12:13:22 GMT -5
In very general terms, by splitting the whole audio range in half, and assigning each half to a different amp, you reduce interactions between them. For starters, each amp channel is working less hard. Beyond that, if either amp channel distorts, that distortion won't affect the other. So, for example, if you turn things up until the bass clips a little, the midrange and high frequencies will remain clean. The current version of "bi-amping" (often referred to as "vertical bi-amping" or "horizontal bi-amping") consists of feeding the same signal to both amplifier channels. The upper and lower sections of the speaker are then separated, and each connected to one of the amplifier channels. Both amplifiers still amplify the entire audio signal; and both halves of the speaker still retain their passive crossover to control which audio frequencies go to each driver. Since the load on each amplifier channel only covers part of the audio frequency range, each is working less hard. This type of bi-amping can give you more power, and allows your system to continue to sound clean, even when playing very loudly (more loudly than usual).. The "bi-amp jumpers" on many speakers are wired to accommodate this sort of connection.) In the original (true) version of bi-amping.... an active crossover is used to separate the audio frequency ranges before sending them to the amplifier channels. The passive crossovers are removed from the speaker, one amplifier channel is connected to the woofer, and the other to the midrange and tweeter. This setup gives more benefits, including better damping for the woofer (because the crossover between the amplifier and the woofer has been omitted). However, this method requires that your speakers be specially wired internally, and also requires the addition of a true active crossover. What’s the purpose of bi-ampung? |
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Post by leonski on Nov 13, 2017 15:12:46 GMT -5
Keith, I'm not certain that Elliot Sound Products would agree with you entirely. The amount of power in a passive biamp system doesnt' really increase. or SEEM to. And while each 'way' of the amp does get a full range signal, you don't reap the benefits. The amp STILL tries to amplify a full range signal and will STILL clip, even though not formally 'under load'. Please recommend section 1.4 of the linked article. I think that explains much better than I could, the downside of the passive system. I use that system on my Maggies, but will reap roughly a 3db 'apparent' power increase when going to an active crossover. sound.whsites.net/bi-amp.htm#act_vs_eff |
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Post by pknaz on Nov 17, 2017 22:41:55 GMT -5
In very general terms, by splitting the whole audio range in half, and assigning each half to a different amp, you reduce interactions between them. For starters, each amp channel is working less hard. Beyond that, if either amp channel distorts, that distortion won't affect the other. So, for example, if you turn things up until the bass clips a little, the midrange and high frequencies will remain clean. The current version of "bi-amping" (often referred to as "vertical bi-amping" or "horizontal bi-amping") consists of feeding the same signal to both amplifier channels. The upper and lower sections of the speaker are then separated, and each connected to one of the amplifier channels. Both amplifiers still amplify the entire audio signal; and both halves of the speaker still retain their passive crossover to control which audio frequencies go to each driver. Since the load on each amplifier channel only covers part of the audio frequency range, each is working less hard. This type of bi-amping can give you more power, and allows your system to continue to sound clean, even when playing very loudly (more loudly than usual).. The "bi-amp jumpers" on many speakers are wired to accommodate this sort of connection.) In the original (true) version of bi-amping.... an active crossover is used to separate the audio frequency ranges before sending them to the amplifier channels. The passive crossovers are removed from the speaker, one amplifier channel is connected to the woofer, and the other to the midrange and tweeter. This setup gives more benefits, including better damping for the woofer (because the crossover between the amplifier and the woofer has been omitted). However, this method requires that your speakers be specially wired internally, and also requires the addition of a true active crossover. What’s the purpose of bi-ampung? Yeah, sorry, my question was targeted at the OP, and should have read "What's your purpose for bi-amping" |
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Post by Hughes, G D on Nov 18, 2017 9:33:28 GMT -5
Yeah, sorry, my question was targeted at the OP, and should have read "What's your purpose for bi-amping" I have 12 channels of amplification so, why not? It all started with a friend who is a stereo purist kind of guy. We used to work shift work together so, long nights sometimes leaves lots of time to conjure up snake oil. Well, you know, you read about this and you read about that and some things you can try and somethings just cost too much to try. First, I bi-wired the fronts when I just had the 7/2100 and was running 5.1 surround and to be honest, I was very skeptical but, I really believe the front stereo pair seemed just a bit cleaner, I bit more clarity in the mids and highs and maybe slightly better bass like an upright bass just sounded...different. Maybe, my imagination but listening at a healthy listening level, ~80db, it got just a little better. After that, I had picked up an Onkyo which allowed for front high/wide so I wanted to try it and having always been a fan of little companies like B&K Components, Sherbourn and not Emotiva, I jumped at the chance to buy the XPA-5 which I thought was a steel at full retail. I think GEN-2 must have been on sale or something. Anyway, with the extra channels, I thought I'd try bi-amping the fronts and so, they have been that way for a while because I can. I don't know if it's better but, I'm sure it's not worse. Listening to very dynamic music can be a real treat. Yo-Yo Ma comes to mind. IDK. May be snake oil. Maybe my old ears are trying to regain their glory days before all the tinnitus. I guess I do it because I can. |
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Post by leonski on Nov 18, 2017 14:09:47 GMT -5
'passive' biamp doesn't really buy you much. I do this with my panels and a pair of stereo amps. One per speaker.
The ultimate goal will be to go to an ACTIVE crossover which eliminates the speaker level crossover, connecting the various speaker drivers directly TO an amp.
Such a crossover goes between the PREamp and the Power Amp(s).
Ridding the amp of the frequencies it no longer has to amplify can buy you as much as 3db additional 'apparent' power. This depends on the crossover frequency, mainly.
My speakers cross @about 600hz, which is near-enough to the 50:50 power point to tell me that each amp 'half' will redline about the same time into 'normal' music. If you were to use an identical pair of amps and have a crossover at say,
5000hz, the LF amp would be far more heavily stressed than the HF amp.
Read the article I linked, above. Elliot Sound Products white papers are very well done and not part of a sales campaign.
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