Hello,
I am toying with the (future) idea of building a pair of 2-way speakers and using an active crossover with two amps to power them.
What I am wondering about is, whether the two amps used for such a system must each handle LF and HF separately, or if each could handle LF on the right channel, and HF on the left channel instead?
The reason why I would want to wire it this way is simply a cabling issue... it would make things much easier in my room if I could power one speaker with one amp, using left for LF and right for HF, and the same on the other speaker.
But I assume now, that this would only make sense if the power amp would be a true dual-mono design, because otherwise I would actually loose the advantage of using separate power amps for different frequencies... if I use LF and HF on the same amp?
Does this make sense, or am I overthinking this?
I have a Nakamichi PA-5... which is not a true dual-mono design as far as I understand... so I am wondering if I should get another PA-5 and do as described, or if I'd be better off with two dual-mono amps or just run long cables...
I am toying with the (future) idea of building a pair of 2-way speakers and using an active crossover with two amps to power them.
What I am wondering about is, whether the two amps used for such a system must each handle LF and HF separately, or if each could handle LF on the right channel, and HF on the left channel instead?
The reason why I would want to wire it this way is simply a cabling issue... it would make things much easier in my room if I could power one speaker with one amp, using left for LF and right for HF, and the same on the other speaker.
But I assume now, that this would only make sense if the power amp would be a true dual-mono design, because otherwise I would actually loose the advantage of using separate power amps for different frequencies... if I use LF and HF on the same amp?
Does this make sense, or am I overthinking this?
I have a Nakamichi PA-5... which is not a true dual-mono design as far as I understand... so I am wondering if I should get another PA-5 and do as described, or if I'd be better off with two dual-mono amps or just run long cables...
That's what I recommend.
Use one stereo amp located beside/behind the active speaker to power the two drivers of the 2way speaker.
Use a second stereo amplifier for the other active speaker.
Use very short amp to speaker cables.
Use long interconnects from a conveniently located Source/Buffer/Pre-amp.
The volume control is in the convenient location.
The stereo amplifier can be made from two identical amplifiers.
or you can build a two channel amplifier with two different amplifiers. Each amplifier is dedicated to it's driver and can be specially assembled to perform at it's best for that driver.
Use one stereo amp located beside/behind the active speaker to power the two drivers of the 2way speaker.
Use a second stereo amplifier for the other active speaker.
Use very short amp to speaker cables.
Use long interconnects from a conveniently located Source/Buffer/Pre-amp.
The volume control is in the convenient location.
The stereo amplifier can be made from two identical amplifiers.
or you can build a two channel amplifier with two different amplifiers. Each amplifier is dedicated to it's driver and can be specially assembled to perform at it's best for that driver.
Should not be a problem at all as far as I can tell.
Running non-dual monos as you suggest means that the PSU is unlikely to be unduly stressed as treble tends to need less power provided your crossover point is appreciably above 350Hz (the average equal power point in music).
Running non-dual monos as you suggest means that the PSU is unlikely to be unduly stressed as treble tends to need less power provided your crossover point is appreciably above 350Hz (the average equal power point in music).
Thanks for your responses.
I now realized that there are actually terms for this question, and I should have asked if vertical bi-amping is preferred over horizontal bi-amping. My idea of connecting would be vertical, and a couple of articles I have read so far indicate that the vertical approach is actually the preferred one—as long as one uses the same power amplifiers.
Looks like I am on the right track then.
I guess it's all about "Intermodulation distortion" of the amplifier, which I don't completely understand yet...
I now realized that there are actually terms for this question, and I should have asked if vertical bi-amping is preferred over horizontal bi-amping. My idea of connecting would be vertical, and a couple of articles I have read so far indicate that the vertical approach is actually the preferred one—as long as one uses the same power amplifiers.
Looks like I am on the right track then.
I guess it's all about "Intermodulation distortion" of the amplifier, which I don't completely understand yet...
Vertical bi-amping will reduce stereo cross-talk, and means both amps are running about as hard (ie, you're not cooking just one). Horizontal bi-amping means you can put more power where its needed.
Chris
Chris
have been using old 800w/ch qsc amplifier for old rcf event 18 bass bins ,crossed over at 310hz with old rcf event 3000 tops on 150w/ch class d diy amp. in my opinion it would be waste of money/power to have qsc playing on top or all cabinets as this 150w/ch is in real life double the power of what is actualy needed, i know that suggested power at 350hz is 50/50 but in real life i never pulled more than 70w/ch from d-class while qsc would occationaly blink red lights 😀 . yeah tops are lot more sensitive than bass and thats probably why this works in this case.
This is DIY, man - there's no such thing as overthinking, or a single right way to do anything in all cases. 😀
Almost all of the 2-ways I build are basically FASTs - essentially a 3-4" fullrange driver generally operating from around 200Hz or so up, and supported by whatever number and size of mid-bass drivers strikes our whim at the time - so there may or not be a big difference in net load impedance and sensitivity of each pass band and corresponding power requirements.
I prefer horizontal bi-amping as it allows for both the very convenient and flexible- if not scrupulously matched - practice of using a pair of whatever stereo amps may be at hand, as well as more careful selection of amp type and power level to suit each driver & enclosures "personality". Some folks just love the synergy of a flea watt SET driving a high sensitivity FR / mid-tweet -when done well, myself included - while the woofers/ sub(s) may be of equal or lower sensitivity and need the torque / HP of a 60-100W SS amp for the heavy lifting
What am I saying, all amps sound the same.
Almost all of the 2-ways I build are basically FASTs - essentially a 3-4" fullrange driver generally operating from around 200Hz or so up, and supported by whatever number and size of mid-bass drivers strikes our whim at the time - so there may or not be a big difference in net load impedance and sensitivity of each pass band and corresponding power requirements.
I prefer horizontal bi-amping as it allows for both the very convenient and flexible- if not scrupulously matched - practice of using a pair of whatever stereo amps may be at hand, as well as more careful selection of amp type and power level to suit each driver & enclosures "personality". Some folks just love the synergy of a flea watt SET driving a high sensitivity FR / mid-tweet -when done well, myself included - while the woofers/ sub(s) may be of equal or lower sensitivity and need the torque / HP of a 60-100W SS amp for the heavy lifting
What am I saying, all amps sound the same.
Right!
I will definitely experiment with both options when the time comes. But the thing is, if I would go for vertical bi-amping, I would think that the amps should be the same, and I may be able to get a nice PA-5 for a good price right now... hence I sort of need to know whether this works and is worth it.
I have a couple of other amps, so a horizontal setup would be no problem, it's just that I would have cables all over the place which is obviously inconvenient and not very wife-friendly 😉
Well you could certainly do a lot worse than a pair of PA5s, so provided your active XO has level controls on each pass band and there's a master level control upstream, it should work like a dream.
I wouldn't lose much sleep over the absence of dual mono power supplies - I think even back then Mr Pass had a good handle on things.
I wouldn't lose much sleep over the absence of dual mono power supplies - I think even back then Mr Pass had a good handle on things.
Yeah, the PA-5 is quite nice... mine has been restored, too.
The active cross-over I would want to use is the Ashly XR1001. I have read quite a few praises for it (on forums), and I don't see too much out there with the same features, apart from a Pass Labs crossover, which is way over my budget.
The active cross-over I would want to use is the Ashly XR1001. I have read quite a few praises for it (on forums), and I don't see too much out there with the same features, apart from a Pass Labs crossover, which is way over my budget.
Time for an update... if anyone still follows this post.
I managed to get a Pioneer D-23 active crossover. After lots of research, I decided that I would like this crossover the most, due to its build quality, countless configuration options etc. It does up to 4-way active, has left/right level controls for each "way", 6-12-18db slopes, and a wide choice of crossover points. The only thing missing is a 24db slope, oh well.
It was a bit of a, well, let's just say "eventful" journey, until the unit arrived from Japan. Shipping damage, seller sent another unit, arrived after 5 weeks, didn't work at first, accepted a partial refund... then cleaned it thoroughly and de-oxit'd a bit, and now it works just fine.
Instead of building new speakers however, I decided to try the D-23 on my current ones first (can be seen here).
So after that big journey of building my first passive crossovers for those, I disconnected it again uhhhh...
Anyway, I did a bunch of experiments with this setup:
I tweaked and tweaked for quite some time, and, although I tried to be skeptical, the result was crystal clear: the active setup sounded much better. The bass player joined the band again, while on the passive system it seemed like he was abandoned to play in the greenroom. The sound also felt more "airy", as if the amps played "at ease". I will refrain from further sound-descriptive poetry... let me just say it sounded much more like music now.
So, long story short, I was hooked. Of course now I needed to try 3-way active amping, disconnecting the passive crossover in the left channel entirely. I tried it first with an older Sansui amp, which was good. But when a really good deal for an Adcom GA-545 appeared on Craigslist, I went for it and just tested the left channel as fully active system tonight; Nakamichi Amp for LOW, Adcom for MID-HIGH, Herron M-150 for HIGH.
It was just wonderful... I really like the Adcom amp. Midrange has improved a great deal, bass is strong but clear. I still have to tweak and learn some more, but so far I am very impressed.
Of course, one could argue it's the room (left channel side may have better acoustics than right channel), maybe it's the fact that the Adcom/Nakamichi just sound better... well, I did swap amps around quite a bit, and the active setup always sounded much more like real music than the right side, which always had a bit of a muffled sound, as if it was playing though a big can or something.
Enough rambling... just felt like I write an update to this post. I will probably start a new thread in a few days with some questions that I still have regarding tri-amping...
I managed to get a Pioneer D-23 active crossover. After lots of research, I decided that I would like this crossover the most, due to its build quality, countless configuration options etc. It does up to 4-way active, has left/right level controls for each "way", 6-12-18db slopes, and a wide choice of crossover points. The only thing missing is a 24db slope, oh well.
It was a bit of a, well, let's just say "eventful" journey, until the unit arrived from Japan. Shipping damage, seller sent another unit, arrived after 5 weeks, didn't work at first, accepted a partial refund... then cleaned it thoroughly and de-oxit'd a bit, and now it works just fine.
Instead of building new speakers however, I decided to try the D-23 on my current ones first (can be seen here).
So after that big journey of building my first passive crossovers for those, I disconnected it again uhhhh...
Anyway, I did a bunch of experiments with this setup:
- Mac Laptop as a source (for convenience... measurements etc.)
- Nakamich CA-5 Pre-amp
- Right Channel into Herron M-150 mono block, and then into the right speaker using its passive crossover
- Left Channel into the Pioneer D-23, "Low" into Nakamichi PA-5 and then directly to the woofers, "Mid-Low" into Herron M-150 mono block and into the mid/high passive crossover.
I tweaked and tweaked for quite some time, and, although I tried to be skeptical, the result was crystal clear: the active setup sounded much better. The bass player joined the band again, while on the passive system it seemed like he was abandoned to play in the greenroom. The sound also felt more "airy", as if the amps played "at ease". I will refrain from further sound-descriptive poetry... let me just say it sounded much more like music now.
So, long story short, I was hooked. Of course now I needed to try 3-way active amping, disconnecting the passive crossover in the left channel entirely. I tried it first with an older Sansui amp, which was good. But when a really good deal for an Adcom GA-545 appeared on Craigslist, I went for it and just tested the left channel as fully active system tonight; Nakamichi Amp for LOW, Adcom for MID-HIGH, Herron M-150 for HIGH.
It was just wonderful... I really like the Adcom amp. Midrange has improved a great deal, bass is strong but clear. I still have to tweak and learn some more, but so far I am very impressed.
Of course, one could argue it's the room (left channel side may have better acoustics than right channel), maybe it's the fact that the Adcom/Nakamichi just sound better... well, I did swap amps around quite a bit, and the active setup always sounded much more like real music than the right side, which always had a bit of a muffled sound, as if it was playing though a big can or something.
Enough rambling... just felt like I write an update to this post. I will probably start a new thread in a few days with some questions that I still have regarding tri-amping...
Been MY experiences that an active crossover works best (gives most audible/pleasing result) when the Speakers and their passives are less than ideally designed.
Sadly that encompasses a Lot of speakers.
Better units exhibit markedly reduced 'improvement' from Actives.
It's Not a magic bullet. Just saying.
That said: doing a Tri Amp may be Sketchy.
Sadly that encompasses a Lot of speakers.
Better units exhibit markedly reduced 'improvement' from Actives.
It's Not a magic bullet. Just saying.
That said: doing a Tri Amp may be Sketchy.
I am not sure what you mean by that?
Regarding the passive crossovers, I built the passive crossovers for those speakers, but I did it to the specs of the manufacturer, it was thus not my design, just my construction.
Yesterday I noticed that the original (digital-active) version of the speaker is crossing at 400Hz and 3000Hz. They don't specify the slopes unfortunately. However, my active crossover settings sounded best when crossed at 200Hz and 4000Hz.
When I set the D-23 to crossover points closer to the manufacturers specs, they sounded worse... actually, in that case the left and right channel sounded very much alike.
So I think that is pretty much a prove for your experience... the passive crossover in my speaker could have been designed better. Still, I do hear an improvement of bass response in the active setup, no matter what settings I choose...
Which brings me to a question, how can I read/calculate from a crossover schematic what crossover points are used? The schematics are here:
http://www.diyaudio.com/forums/multi-way/239240-schematics-crossover-my-first-need-help.html
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