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Post by novisnick on Apr 27, 2014 11:10:27 GMT -5
That's what I thought. Thanks so much boom. What a great forum and wonderful friends. Nick |
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Post by novisnick on Apr 27, 2014 11:12:26 GMT -5
On the amp, that can be a single post for the left and a single post from the right,,,,correct?
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Post by dpohlman on Apr 27, 2014 11:40:05 GMT -5
For the person asking for the pictures/diagrams:
As boomzilla's vertical bi-amping diagram shows, the speakers must have two sets of binding posts meaning they have independent passive cross-overs for both the low frequency (woofer(s) and for the mid/high frequency (midrange/tweeter).
You would remove the jumper cables or bridge straps to allow each set of binding posts to be driven independently. As boomzilla's diagram also shows in the connections, it is necessary for your pre-amp to feed both the right and left channel of the amp with the same signal (Y - cable needed).
Obviously his diagram only shows the set-up for driving one speaker, but the same would repeat for the left channel. In theory (and I believe in practice) this arrangement minimizes any cross talk/distortion between channels (same signal to both left and right inputs and outputs of the amp). It also allows uses of much of the amps power supply to support the low frequency element, but also still provides outstanding power to the mid/high frequencies as well. Finally, this approach also presents a much easier load for the amplifier to drive vs. trying to run it in a mono-mode (assuming it has that option) - helping it run cooler.
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Post by eclypse on May 8, 2016 12:10:20 GMT -5
Is vertical bi amping like what I'm doing with 2 xpa-1L amps and a single xpa-2? Ea xpa1l is connected to the high end connection of the speakers and 1 channel off the xpa-2 is connected to the low end of ea speaker. Obviously would be better if I had 2 xpa-2s runing ea low end speaker but best would be 4x xpa-1ls or 2 xpa-1L and 2x xpa-1. |
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Post by cheapthryl on May 8, 2016 15:57:50 GMT -5
Pretty much. You understand the concept. One more thing to do is run amps with the same gain for best results.
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Post by repeetavx on May 8, 2016 20:18:54 GMT -5
Is vertical bi amping like what I'm doing with 2 xpa-1L amps and a single xpa-2? Ea xpa1l is connected to the high end connection of the speakers and 1 channel off the xpa-2 is connected to the low end of ea speaker. Obviously would be better if I had 2 xpa-2s runing ea low end speaker but best would be 4x xpa-1ls or 2 xpa-1L and 2x xpa-1. What your doing is called horizontal bi-amping. And your doing it exactly right. |
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Post by leonski on May 8, 2016 21:01:12 GMT -5
1 amp per speaker. Do NOT bridge amps with these guys. The impedance is between 3 and 5 ohms up to 600hz, which is OVER 50% of the power needed for 'normal' music. I've heard FEW if any persons say bridging actually sounded better, anyway. Do what I do. 1 amp behind EACH speaker. Here are the Stereophile Measurments of the Revel Ultima Salon 2 Speaker. www.stereophile.com/content/revel-ultima-salon2-loudspeaker-measurements#O6q96ovVGz150qCx.97For better or worse, it is a 4-way speaker. This means 3 crossover points and a potential set of bandpass filters which will REALLY complicate things. The crossover at 575hz is where I'D break into the crossover since this is near enough the 50:50 power point to not matter. Each amp will come close to redline at about the SAME TIME given a normal distribution of frequencies and power demands. Since the crossover is on 4 seperate boards, any proposed alterations should be fairly easy. OMITTING the supplied jumpers to the 2 pair of binding posts of course, seperates the speaker for biamp use. I DO NOT see any call-out as to WHAT drivers or frequencies are so-seperated, though I would split the posts at the 575hz crossover. When biamping GAIN is generally more important than sheer power. Matched amps make that a no-brainer. Next Step? GUT THE SPEAKER crossover and get something like a MiniDSP and to ACTIVE LINE LEVEL CROSSOVER. This, if done with a stereo pair of amps COULD give you an additional 3db (double) power bump. But, SOME speaker level crossovers would need to be retained OR go to 4 amps per speaker! This would require knowing a LOT about the factory crossover AND the willingness to spend a LOT of time duplicating the factory setup OR perhaps spending a LOT of time with a calibrated microphone and a program like REW. The simple way is both rewarding and easy. Going Active on a speaker like this is a real project. |
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Post by Wideawake on May 8, 2016 23:22:52 GMT -5
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Post by AudioHTIT on May 8, 2016 23:45:08 GMT -5
There is some incorrect information disseminated in this thread. I suggest you read the following articles before you decide to continue on the bi-amping path. I'd say that decision was made about two years ago ... |
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Post by leonski on May 9, 2016 0:48:12 GMT -5
BINGO: When using the speaker level crossover not much or ANY advantage is to be had. BOTH amps to the speaker STILL amplify ALL frequencies. It is only when you go to either a passive OR active line level crossover that you LIMIT the out of band signals TO the amps and at the SAME TIME you eliminate the speaker level crossover which is generally a WASTE OF POWER. When I bought a pair of stereo amps for my panels, it was with the LONG TERM goal of ridding myself of the speaker crossover and going to the MiniDSP active crossover. You can gain as much as 3db 'apparent' power by this means. So my 200x2 amps will ACT like almost 400x2 EACH AMP. A passive crossover CAN work, but changing crossover points requires some calculation AND you need to know the input impedance of the amp and the OUTput impedance of the PRE. Getting the active or passive line level system working correctly with a 4=way speaker would be QUITE the task. |
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Post by repeetavx on May 9, 2016 10:58:51 GMT -5
Bridging an amp raises the noise floor. Usually only inefficient speakers would benefit from power greater than its rated power.
Only you can decide if separating the current flow between the woofer and tweeters increases the quality of the sound presentation of your speakers.
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Post by leonski on May 9, 2016 12:27:14 GMT -5
Raise the noise floor? sounds reasonable.
As for speaker 'power'? Well, speakers don't have watts. I find the ratings to be so much marketing nonsense. Keep your ears OPEN for distortion. Speakers CHANGE in performance as they get hot. Don't forget that a home speaker is really no more than about 1% efficient. Some of the VERY highest sensitivity big-box designs can go nearly 2%, but that's a BIG speaker!
The rest is HEAT.
True, LINE LEVEL crossovers can and DO help make the most of available amp power.
And OH! BTW, look at the measured data for the Revel of the OP. I don't know that it'd work well 'bridged', anyway. The impedance is very low up to about 600hz.
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