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Post by Mikomill on Feb 12, 2020 11:07:12 GMT -5
I have a question for all the emotiva experts regarding bi amping.
my current home made speakers require 3 channels of amplification per speaker to drive the 11" Focal woofer, 4 1/2" mid and Morel tweeter. each speaker is using a minidsp hd as a crossover.
I'm using 6 channels of amplification to drive them.
Tweeters will use an Emotiva A100, 50 watts per channel stereo amp
Mids will use 2 Emotiva XPA-100 Mono amps, 250 watts per amp. (Probably more than i need?)
Woofers will use my Emotiva XPA-2 stereo amp, 250 watts per channel.
Do you think i would loose any SQ by using 1 of the 2 XPA-100 mono amps that i have to run the woofers and use the A100 amp to run the midrange and tweeter of each speaker? I would need to get another A100 amp for the other speaker to do that. I would then be able to locate each set of 2 amps behind each speaker and use shorter lengths of speaker wires. I would be eliminating the XPA-2 completely and that a lot of watts taken out of the system and i'm not sure how that would effect the sound.
Does anyone have any thoughts or suggestions?
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Post by Deleted on Feb 12, 2020 11:29:42 GMT -5
I have a question for all the emotiva experts regarding bi amping. my current home made speakers require 3 channels of amplification per speaker to drive the 11" Focal woofer, 4 1/2" mid and Morel tweeter. each speaker is using a minidsp hd as a crossover. I'm using 6 channels of amplification to drive them. Tweeters will use an Emotiva A100, 50 watts per channel stereo amp Mids will use 2 Emotiva XPA-100 Mono amps, 250 watts per amp. (Probably more than i need?) Woofers will use my Emotiva XPA-2 stereo amp, 250 watts per channel. Do you think i would loose any SQ by using 1 of the 2 XPA-100 mono amps that i have to run the woofers and use the A100 amp to run the midrange and tweeter of each speaker? I would need to get another A100 amp for the other speaker to do that. I would then be able to locate each set of 2 amps behind each speaker and use shorter lengths of speaker wires. I would be eliminating the XPA-2 completely and that a lot of watts taken out of the system and i'm not sure how that would effect the sound. Does anyone have any thoughts or suggestions? Haven't anything really to add but only sharing my initial thoughts. I see that you're using an active crossover which requires the 6 channels of amplification. If you've already pretty much set up your active crossover as to where you'd like it have you thought about replicating the crossover points and db roll off with passive crossovers? I'm sure you may well imagine running a single channel per side through passive crossovers might cut down on a lot of equipment. William |
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Post by Mikomill on Feb 12, 2020 11:40:47 GMT -5
i thought about that but the cost of good quality crossover parts can add up very quickly and the flexibility of the 4 crossover presets are eliminated with a passive crossover. Also, I'm a mechanical Engineer and i learned a long time ago to leave the electrical stuff to someone more qualified.
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KeithL
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Post by KeithL on Feb 12, 2020 11:42:36 GMT -5
Interesting... and the answer will depend, to a degree, on where the crossover points are located, and how loud you like your music.
Here's what I think.... 50 watts should be plenty for each midrange and tweeter (and the A-100 is actually a pretty beefy little amp). 250 watts should be plenty for each woofer.
However, to be quite honest, while it's theoretically nice to be able to locate the amps right next to the speakers, I'm not quite convinced that it actually matters. (A few feet of speaker wire really doesn't make a significant difference in sound... you didn't say how far apart your speakers are.)
The bottom line is this. I think you'll have plenty of power and you won't notice any difference. In general, most of the power goes into frequencies below what the midrange would normally be handling....
(And, from your choice of drivers, I sort of suspect you don't plan to be blasting Metallica at 120 dB anyway.) However, and I can't substantiate this with anything specific, I think I'd be happier using the XPA-2 than the pair of XPA-100's to run the woofers.
(There's nothing whatsoever wrong with the XPA-100's... but I think I just like the XPA-2 better...)
Again.... this is absolutely positively just my personal opinion... 
I have a question for all the emotiva experts regarding bi amping. my current home made speakers require 3 channels of amplification per speaker to drive the 11" Focal woofer, 4 1/2" mid and Morel tweeter. each speaker is using a minidsp hd as a crossover. I'm using 6 channels of amplification to drive them. Tweeters will use an Emotiva A100, 50 watts per channel stereo amp Mids will use 2 Emotiva XPA-100 Mono amps, 250 watts per amp. (Probably more than i need?) Woofers will use my Emotiva XPA-2 stereo amp, 250 watts per channel. Do you think i would loose any SQ by using 1 of the 2 XPA-100 mono amps that i have to run the woofers and use the A100 amp to run the midrange and tweeter of each speaker? I would need to get another A100 amp for the other speaker to do that. I would then be able to locate each set of 2 amps behind each speaker and use shorter lengths of speaker wires. I would be eliminating the XPA-2 completely and that a lot of watts taken out of the system and i'm not sure how that would effect the sound. Does anyone have any thoughts or suggestions? |
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Deleted
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Post by Deleted on Feb 12, 2020 11:56:21 GMT -5
i thought about that but the cost of good quality crossover parts can add up very quickly and the flexibility of the 4 crossover presets are eliminated with a passive crossover. Also, I'm a mechanical Engineer and i learned a long time ago to leave the electrical stuff to someone more qualified. Can most certainly appreciate what you're suggesting. Sure you already know but there are DIY calculators. Don't know how accurate they are. www.diyaudioandvideo.com/Calculator/SpeakerCrossover/I worked in car audio for years and used to make my own passive crossovers. However, that was a couple of decades ago and would need a refresher course. I don't remember coils and caps being that much but again that was decades ago. I'd be really tempted to use the mini dsp to crossover the woofers [and keep the active design for flexibility] but I'd lean towards a two way passive cross over for the mids and highs. That would result in reducing from 6 channels to only 4 in a bi-amp L and R setup. |
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Post by Mikomill on Feb 12, 2020 11:57:09 GMT -5
Keith, that's great advise, thanks for your input. I've always liked the sound of the XPA-2 and i do think it sounds a bit better then the XPA-100 too.
I wasn't expecting a benefit in SQ by locating the amps behind the speakers, it would get them out of the stereo cabinet though, better ventilation. It would also free up the XPA-2 to be used for other channels but require me to purchase another less expensive stereo amp for the tweeter and midrange.
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Post by Mikomill on Feb 12, 2020 11:59:39 GMT -5
i thought about that but the cost of good quality crossover parts can add up very quickly and the flexibility of the 4 crossover presets are eliminated with a passive crossover. Also, I'm a mechanical Engineer and i learned a long time ago to leave the electrical stuff to someone more qualified. Can most certainly appreciate what you're suggesting. Sure you already know but there are DIY calculators. Don't know how accurate they are. www.diyaudioandvideo.com/Calculator/SpeakerCrossover/I worked in car audio for years and used to make my own passive crossovers. However, that was a couple of decades ago and would need a refresher course. I don't remember coils and caps being that much but again that was decades ago. I'd be really tempted to use the mini dsp to crossover the woofers but I'd lean towards a two way passive cross over for the mids and highs. That would result in reducing from 6 channels to only 4 in a bi-amp setup. ....that's not a bad idea! |
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KeithL
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Post by KeithL on Feb 12, 2020 13:58:09 GMT -5
There are two drawbacks to passive crossovers - and they are somewhat related.
The first is that good quality passive crossover components can be somewhat expensive. (But they aren't too bad if you stay away from "silly audiophile components" that really don't make any difference.) However, this is also a problem because it limits your ability to adjust and fine tune things (every time you want to try a new setting you need to buy more parts).
But, beyond that, crossover design is rather more complicated than many people think. That little DIY calculator is cute, and it probably does very accurate calculations, but those calculations are based on "standard values". They're assuming that an 8 ohm woofer is really 8 ohms across the audio band - which isn't at all realistic. (Every 8 ohm woofer is different, both electrically and mechanically, but that calculator treats them all as "8 ohm resistors".) The measurements and calculations necessary to compensate for the differences between real drivers and real cabinets make doing it well a lot more complicated. And, in most cases, you end up doing a lot of careful listening, and then making adjustments based on what you hear or measure. (This is really difficult if you have to order each new value you want to try - and then wait for it to arrive.)
With an electronic crossover all of this becomes much simpler.... Because changes are simply a matter of changing number in a program rather than changing parts. (And, as they say, "bits are really cheap".)
I would also note that what we're talking about here is what I would call REAL bi-amping (which is what used to be simply called "bi-amping"). (In general, both "vertical bi-amping" and "horizontal bi-amping" are terms used to describe using multiple amplifiers to drive parts of a speaker, without bypassing the individual passive crossover sections inside a speaker.)
i thought about that but the cost of good quality crossover parts can add up very quickly and the flexibility of the 4 crossover presets are eliminated with a passive crossover. Also, I'm a mechanical Engineer and i learned a long time ago to leave the electrical stuff to someone more qualified. Can most certainly appreciate what you're suggesting. Sure you already know but there are DIY calculators. Don't know how accurate they are. www.diyaudioandvideo.com/Calculator/SpeakerCrossover/I worked in car audio for years and used to make my own passive crossovers. However, that was a couple of decades ago and would need a refresher course. I don't remember coils and caps being that much but again that was decades ago. I'd be really tempted to use the mini dsp to crossover the woofers [and keep the active design for flexibility] but I'd lean towards a two way passive cross over for the mids and highs. That would result in reducing from 6 channels to only 4 in a bi-amp L and R setup. |
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Deleted
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Post by Deleted on Feb 12, 2020 15:23:42 GMT -5
There are two drawbacks to passive crossovers - and they are somewhat related.
The first is that good quality passive crossover components can be somewhat expensive. (But they aren't too bad if you stay away from "silly audiophile components" that really don't make any difference.) However, this is also a problem because it limits your ability to adjust and fine tune things (every time you want to try a new setting you need to buy more parts).
But, beyond that, crossover design is rather more complicated than many people think. That little DIY calculator is cute, and it probably does very accurate calculations, but those calculations are based on "standard values". They're assuming that an 8 ohm woofer is really 8 ohms across the audio band - which isn't at all realistic. (Every 8 ohm woofer is different, both electrically and mechanically, but that calculator treats them all as "8 ohm resistors".) The measurements and calculations necessary to compensate for the differences between real drivers and real cabinets make doing it well a lot more complicated. And, in most cases, you end up doing a lot of careful listening, and then making adjustments based on what you hear or measure. (This is really difficult if you have to order each new value you want to try - and then wait for it to arrive.)
With an electronic crossover all of this becomes much simpler.... Because changes are simply a matter of changing number in a program rather than changing parts. (And, as they say, "bits are really cheap".)
I would also note that what we're talking about here is what I would call REAL bi-amping (which is what used to be simply called "bi-amping"). (In general, both "vertical bi-amping" and "horizontal bi-amping" are terms used to describe using multiple amplifiers to drive parts of a speaker, without bypassing the individual passive crossover sections inside a speaker.)
Can most certainly appreciate what you're suggesting. Sure you already know but there are DIY calculators. Don't know how accurate they are. www.diyaudioandvideo.com/Calculator/SpeakerCrossover/I worked in car audio for years and used to make my own passive crossovers. However, that was a couple of decades ago and would need a refresher course. I don't remember coils and caps being that much but again that was decades ago. I'd be really tempted to use the mini dsp to crossover the woofers [and keep the active design for flexibility] but I'd lean towards a two way passive cross over for the mids and highs. That would result in reducing from 6 channels to only 4 in a bi-amp L and R setup. I think the setup would be as simple as can be. I mean the woofer would be on its own mini dsp active crossover and amp and therefore fully adjustable. The midrange and tweeter would also be on a mini dsp and the active crossover hi passing the midrange [assuming or "if" rolling off naturally to the tweeter]. The tweeter alone might be the only passive crossedover speaker in the system. Correct if wrong but that's about the simplest solution which might only require caps. I guess one could pass the signal between X [actively] and Y [passively] to the midrange but that might also be done to the midrange actively depending on wiring solution and everything above Z [passively] to the tweeter or even vice versa. I imagine that one could play with the passive crossovers to create a zobel circuit to compensate for non linearity etc [the extent of my memory] which would require a little more inventory or parts I was merely suggesting that if crossover frequencies are pretty much "set" in the system that they could be replicated passively to reduce the amount of equipment. Correct me if wrong but most of the impedance variations compensated by more indepth passive crossovers generally pertain to the woofers? I mean, I know some passive crossovers are a work of art and require a lot of headwork to create. I would actually love to see the passive crossover system in my Tektons but I "heard" they are pretty well secured in the cabinets [sealed] to prevent prying eyes. Of course mkanter may be a "tweeker" and utilize different crossover points for various music types or source formats such as movies etc and if so I could definitely understand why he'd prefer the active crossover system. Anyhoot I can definitely appreciates mkanter's current system. Much appreciate your responses too Keith! |
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KeithL
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Post by KeithL on Feb 12, 2020 16:38:44 GMT -5
The short answer to all of this is sort of that it depends on what you want to do.
A single capacitor will provide a passive first order high pass crossover - which isn't especially sharp. Assuming that you ended up wanting a simple first order then doing that passively with a capacitor would do the job. The rest really depends on the individual components you're using. For example, many midranges and tweeters have a peak or dip somewhere in their frequency response, which requires a tuned RLC of some sort to eliminate or tame. (But that will depend on the specific driver you're using and over what frequency range.) (In general, all drivers have one or more resonances, which much either be avoided or tamed, so that depends on the driver and the frequency range you want it to cover.)
In general active crossovers can be far more precise and complex... since you aren't limited by either parts count or the losses inherent in passive components.
The Tektons have multiple tweeters in a pattern or array. The frequency response and directional properties of the entire array of tweeters will depend on what signal is being sent to each. It's quite possible that different tweeters are covering slightly different frequency ranges - or that some receive a signal that is delayed relative to others. (You're basically treating them all as one big "virtual tweeter"... but one where you can control the "size" and "response" separately over different frequency ranges.) When you start talking about multiple drivers covering the same range of frequencies, and "beam steering", and "array response", it all gets VERY complicated.
I wouldn't be at all surprised if the center tweeter in each group has a frequency response that extends higher than the circle around it.
You get wider dispersion at high frequencies by limiting the driver area... and, at higher frequencies, less power handling is required. Note that this is just a wild guess... so their choices there might be entirely different. The point is that, when it comes to multiple speaker arrays, things have gone far beyond "just dividing up the frequency ranges".
You often see this even with relatively simple speakers. For example, with most "MTM center channel speakers", the two identical mid/woofers are actually being driven with different signals.
(Often the high frequency response of only one is limited so that, above a certain frequency, only one is working... which reduces unwanted comb filter effects that would otherwise occur.)
There are two drawbacks to passive crossovers - and they are somewhat related. The first is that good quality passive crossover components can be somewhat expensive. (But they aren't too bad if you stay away from "silly audiophile components" that really don't make any difference.) However, this is also a problem because it limits your ability to adjust and fine tune things (every time you want to try a new setting you need to buy more parts). But, beyond that, crossover design is rather more complicated than many people think. That little DIY calculator is cute, and it probably does very accurate calculations, but those calculations are based on "standard values". They're assuming that an 8 ohm woofer is really 8 ohms across the audio band - which isn't at all realistic. (Every 8 ohm woofer is different, both electrically and mechanically, but that calculator treats them all as "8 ohm resistors".) The measurements and calculations necessary to compensate for the differences between real drivers and real cabinets make doing it well a lot more complicated. And, in most cases, you end up doing a lot of careful listening, and then making adjustments based on what you hear or measure. (This is really difficult if you have to order each new value you want to try - and then wait for it to arrive.) With an electronic crossover all of this becomes much simpler.... Because changes are simply a matter of changing number in a program rather than changing parts. (And, as they say, "bits are really cheap".)
I would also note that what we're talking about here is what I would call REAL bi-amping (which is what used to be simply called "bi-amping"). (In general, both "vertical bi-amping" and "horizontal bi-amping" are terms used to describe using multiple amplifiers to drive parts of a speaker, without bypassing the individual passive crossover sections inside a speaker.)
I think the setup would be as simple as can be. I mean the woofer would be on its own mini dsp active crossover and amp and therefore fully adjustable. The midrange and tweeter would also be on a mini dsp and the active crossover hi passing the midrange [assuming or "if" rolling off naturally to the tweeter]. The tweeter alone might be the only passive crossedover speaker in the system. Correct if wrong but that's about the simplest solution which might only require caps. I guess one could pass the signal between X [actively] and Y [passively] to the midrange but that might also be done to the midrange actively depending on wiring solution and everything above Z [passively] to the tweeter I imagine that one could play with the passive crossovers to create a zobel circuit to compensate for non linearity etc [the extent of my memory] which would require a little more inventory or parts I was merely suggesting that if crossover frequencies are pretty much "set" in the system that they could be replicated passively to reduce the amount of equipment. Correct me if wrong but most of the impedance variations compensated by more indepth passive crossovers generally pertain to the woofers? I mean, I know some passive crossovers are a work of art and require a lot to create. I would actually love to see the passive crossover system in my Tektons but I "heard" they are pretty well secured in the cabinets [sealed] to prevent prying eyes. Of course mkanter may be a "tweeker" and utilize different crossover points for various music types or source formats such as movies etc and if so I could definitely understand why he'd prefer the active crossover system. Anyhoot I can definitely appreciates mkanter's current system. Much appreciate your responses too Keith! |
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Post by Mikomill on Feb 14, 2020 8:00:20 GMT -5
Does anyone have any thoughts on biamping with my current amps or suggestions on a stereo amp to biamp the mids? That would free up 2 xpa-100 monoblock amps that are probably overkill for two 4 1/2" midrange drivers.
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