As I observed in post #16, that should work fine since the lowest frequencies are omnidirectional.
Bi-amping vs dual mono setup. Which would sound better?
- Thread starter Cajunchuck
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twiiii
Lunatic Member
Running mono is less costly that bi- amping for sure. But only 3 db increase of power is really of no use. I tried it three times using both tube and SS amps. If your speakers can handle the extra power you really a 5 db increase to really hear a big difference. What I have found over the years its better to spend the money on better speakers than on a little more power. If the speakers don't cut it in the first place adding e db of power is not very satisfactory. Some times changing amps can make a lot of difference, depending on the short comings of the amps you have now. If you have a great amp I see Avery small chance you will hear an improvement.
Sure there are modern amps with 3 channels, primarily intended for home theater use (note the THX logo) but even then the options are limited and they are certainly not vintage.
And while the lowest frequencies are omnidirectional, not all tri-amped set-ups send just the lowest frequencies to the woofer.
And while the lowest frequencies are omnidirectional, not all tri-amped set-ups send just the lowest frequencies to the woofer.
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This is what I run tri-amped. Includes two Marantz 170DC amps, a Marantz 1180DC integrated console, and custom made electronic crossover. The speakers, crossover, and HF eq units (not shown here but placed between the power amp and horns) are all probably "one-offs" made by The Mastering Labs. I got them from a recording studio.
And these are the slopes:
604E2 Horn:
604E2 woofer:
Aux woofer:
The two 170DC amps push the four woofers (with one amp doing the 604 woofers and the other doing the aux woofers) and the 1180DC pushes the horns.
In theory, one would want to push the aux woofers with the 1180DC because it offers a bit more wattage per channel (rated at 90 WPC vs 85 WPC for the amps) and that's where you want to put the power.
But, there are other considerations too.
The 1180DC also serves as the preamp, so less draw off of its power supply would be thought to have less impact on the preamp circuits. Obviously, the horns draw very little relative to the woofers.
Also, the horns would draw so little power as to render the meters on the 170DC amps as pretty much dead with very little movement. Even the woofers only shows a few watts of movement.
Would anyone have done this differently?
And these are the slopes:
604E2 Horn:
604E2 woofer:
Aux woofer:
The two 170DC amps push the four woofers (with one amp doing the 604 woofers and the other doing the aux woofers) and the 1180DC pushes the horns.
In theory, one would want to push the aux woofers with the 1180DC because it offers a bit more wattage per channel (rated at 90 WPC vs 85 WPC for the amps) and that's where you want to put the power.
But, there are other considerations too.
The 1180DC also serves as the preamp, so less draw off of its power supply would be thought to have less impact on the preamp circuits. Obviously, the horns draw very little relative to the woofers.
Also, the horns would draw so little power as to render the meters on the 170DC amps as pretty much dead with very little movement. Even the woofers only shows a few watts of movement.
Would anyone have done this differently?
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On another vein, the two small speakers sitting on the floor are original Chartwell LS3/5A (~$2K/pr now).
This is what their crossovers look like. Obviously, there is a whole lot more than just low and high pass going on here, and this would take some/lots of eq if bi-amping so these probably would not be good candidates.
This is what their crossovers look like. Obviously, there is a whole lot more than just low and high pass going on here, and this would take some/lots of eq if bi-amping so these probably would not be good candidates.
I think you'll find a wide range of MC amps on the market today. I don't recall *vintage* being a requirement.
I believe the OP is talking about commercially designed speakers - not one off tri-amped-from-the-start designs.
Clearly, those were not intended for bi-wire/bi-amp use as you commonly find today.
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What I find to be of use in this example is threefold: improved separation and thus wider soundstage you find with mono amps, isolating potential bass clipping from upper driver(s) and collectively, a stiffer power supply for better dynamics.
The 3 db added power is secondary to those qualitative factors.
You could leverage those advantages with your twin 207s, but if memory serves choose to not.
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Flexibility .. more amps can definitely get ya there ..
Just to add another wrinkle ..
Horizontal bi-amping with the speaker's included passive crossover will get you the advantage of using two different sounding amps depending on what you like without upsetting the speaker designer's intended driver balance ....
I like the sound of tube amps on the midrange/treble and big high current Solid State amps on the bass ..
YMMV
Just to add another wrinkle ..
Horizontal bi-amping with the speaker's included passive crossover will get you the advantage of using two different sounding amps depending on what you like without upsetting the speaker designer's intended driver balance ....
I like the sound of tube amps on the midrange/treble and big high current Solid State amps on the bass ..
YMMV
Well said.
Can't understand why so many jump to the conclusion this is about watts when in many cases just one of the amplifiers involved has enough to melt the speakers without any help lol.
I took that approach as a teen with tri-amped Braun LV1020s. I put The Fisher tube amps on the tweeters leaving woofer/midrange driven by the on board amplifiers.
Now as a coherency freak who enjoys the benefits of using mono amps, I'm with Luke Manley and Peter McGrath as they put together what was reported to be a really nice system at RMAF a few years back. Scroll down for Luke's comments.
Having said that, I use powered subs in the HT, but they are low passed at 40 hz.
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For those who are bi-amping and more specifically, tri-amping, how do you go about setting your levels?
I've been taking the three drivers to the same volume level at the seat position using pink noise on the "C" weighted scale. But I think this is making it too bright and probably should be using "A" weighting.
But, do you set the highs to the same volume as the lows, or let them "roll off" a bit, and if so, how much?
I've been taking the three drivers to the same volume level at the seat position using pink noise on the "C" weighted scale. But I think this is making it too bright and probably should be using "A" weighting.
But, do you set the highs to the same volume as the lows, or let them "roll off" a bit, and if so, how much?
Nixxuz
Super Member
Horizontal here, as tubes for the mids/highs, and SS for the lows. The main benefit I see is the ability to use disparate efficiency drivers. My FR drivers are 99dB efficient. My woofers are 84dB. Obviously not gonna work properly off the same amp at the same volume. I run sweeps for each driver to determine volume, while keeping track on a real time FR analyzer. Seems to work alright for me, but I assume others can be a bit more exacting.
I've never been accused of being exacting .. I just use my ear, but one of the benefits is the ability to easily compensate with a touch more upper, or lower frequency depending on the room, the material, your preference, or your state of mind ..
My guess is most folks don't tinker with custom systems that have no established response curve.
With the HT using powered subs, I used in-room measurements for the bottom three octaves to set xover settings, level and parametric EQ attenuation for the most linear response.
My guess is most folks don't tinker with custom systems that have no established response curve.
With the HT using powered subs, I used in-room measurements for the bottom three octaves to set xover settings, level and parametric EQ attenuation for the most linear response.
For my home theater/main audio set-up, I just let the Yamaha do its YPAO thing.
But I don't believe that we are talking about bi-amping for subs here, which is totally different.
How is using independent amplifiers for separate frequency ranges *totally* different?
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Its been a while since I set my triamped system up. Basically I don't have any of the original speaker crossover left, but I do have protection caps and a resistor on both the mid (LE85) and high (077). When I replaced the old LE15B's and installed the new 2216ND1's I did some REW work at the speaker (1" from each driver separately and 1 meter together), to try to get the response corrected there first. Then after some success I focused at the listening chair with the calibrated mic and REW to try to get it flatter there. First with REW's Auto EQ and then I just kept hammering the dents by running frequency sweeps over and over, and manually manipulating the correction with the PEQ's.
The levels, well each amp of mine has its own pots, which I set all first at 50%. This was fairly close but while I was manipulating the curve with PEQ's I also would adjust the individual amplifiers volume some, so ended up with the LF amp set at around 60%, and the mid and hi frequency amps at about 45%. after that, I was mainly concerned with a flat response from 20>20Khz. That was my target. This was the final result (after a month of driving my wife nuts with the frequency sweeps).
After that I listened some, and found that the mids were a little too bright so I just backed off a (very) little on the mid frequency amps volume pot. I suppose I could have backed off in the mid frequency from within the MiniDSP interface itself too.
And as I think I'm a little tone deaf at the frequencies from 7khz up, not having a rolloff was what suited me best although I did experiment with various rolloffs too.
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WaynerN
Addicted Member
I do not like vertical bi-amping as it puts an unbalanced load between the channels of an amp. I would rather see one amp run the left and right LF and one amp run the left and right HF. However, in most cases of horizontal bi-amping, one of the amps should have a volume control so that the outputs of both can be matched (due to different input impedances, etc.). Also mixing SS and tube amps can present a problem as many tube amps have a lower gain rate compared to SS designs.
There are also claims of improved performance from bi-wiring, running 2 sets of cables from each amp channel to the LF and HF drivers as I do with my Martin Logan reQuests.
There are also claims of improved performance from bi-wiring, running 2 sets of cables from each amp channel to the LF and HF drivers as I do with my Martin Logan reQuests.
fill35u
Super Member
If you're doing the ubiquitous 2-way with a 15" woofer crossed to a horn, you're hopefully crossing low enough to mitigate abrupt change in directivity. So you're going for a larger CD and giving up a little on the very top (the eternal 2-way compromise). Such CD's are usually rated well over 100W (with proper XO to limit excursion at the bottom end).
However, that XO point is going to have to be somewhere around 1kHz, depending whether you compromise on directivity or maximum volume. Power spectral density of music is balanced above and below about 250-350Hz, depending of course on the particular music. So the woofer will be using a good portion of the power between that balance frequency and the XO to the CD. It does seem that in that case a lot less power is needed for the tweeter.
I use three-way speakers and biamp between the woofers and the combined teeters and mids(passive XO retained for the tweeter also confers DC fault protection). The XO is at 300Hz, so it works out nicely. I still use more power on the woofers, because they present more reactive impedance and can handle the power.
All this talk about improved channel separation from vertical biamping is nonsense. You only need 30dB max (20dB for most people under most conditions). In a real setup in a real room, there's a lot of interaural crosstalk going on, no matter how perfect the amps and speakers. Even exceptional phono cartridges might only have 30-35dB of channel separation, but most are well below that. The analog tape machines that much classic music was recorded and mastered on had less than 50dB of channel separation. Any amplifier with less than 40dB of channel separation would be an atrociously bad design or broken, more so if it degraded to that degree under heavy load. Most amps spec better than 70dB of channel separation, far more than necessary. If you were really worried about channel separation, vertical biamping would be the worst case. There's much more difference between the high/low signals (and crosstalk would have more consequences, especially IM distortion in the amp and drivers) than there is difference between L-R channels.