View Full Version : Bi-wiring DOES work if you have external crossovers.
I would encourage all those who have external crossovers to place them as close as poss. to their amps and then run long(er) bi-wire cables out to their speakers.
I built my DIY speakers - World Audio Wd25TEx - with external crossovers and I have always positioned their respective crossovers in boxes under a bureau strategically placed between them via say 60cms of bi-wired cable and with 5m of underfloor single stereo cable from amp to crossovers.
Well fast forward to last month when I read a resurrected 10 year old thread on pfm DIY which included a post by Les Wolstenholme saying "the sooner you divide the signal into its frequency groups (Bi or Tri wire ) the clearer it all sounds", no explanation why but a few had done it and rated the results so I now have placed my crossovers just 30cms from my amp and run bi-wired cables to my speakers. Boy does it work.
Donīt know why and donīt care. I understand that in fact there is no change in the electrical circuit but I swear itīs like having a new, better amp.
Just do it if you get the chance.
Stratmangler
25-04-2016, 23:38
What you've described is not biwiring.
All you've done is connect the crossover with very long tails to the drivers.
Yes, of course. Bi-wiring has always been taken as beginning at the amp - in this case it begins at the crossover (inevitably) - The physical distance from amp to speaker is a constant but it does involve almost double the amount of cable which, I think, is what most of us refer to when talking about bi-wiring being a bit of a waste of time. It certainly did nothing for me in the traditional guise and now it certainly does..
Better still if you have a pre-power that is suitable - place the power amps as close to the speakers as possible and use a very low capacitance cable from pre to power. Not really suitable for passive preamps, but many active preamps can drive several metres of interconnect with no issues (my old Croft hates it, but it's an exception).
Simon_LDT
27-04-2016, 16:46
I've just came from a bi-wired connection. Used to have 2x2.5mm Van Damme Blue but decided to try 4mm single wire (same VD Blue), with 4mm wire jumpers between the posts. I'm not hearing any difference at all. Then again my speakers have passive crossovers and from everything I've read on the subject, bi-wiring will only give benefits when using active crossovers (which makes sense).
There seems to be some confusion amongst contributors as to what constitute bi-wiring, bi-amping and (possibly) active operation.
However, to address the topic, I'm not sure what the actual technical difference is in moving the crossover in this manner. All the signal and return paths stay the same, the only thing that has changed is the cable that goes between the amplifier and the crossover becomes short and the cables from the crossover to the drive units becomes long.
In my own case I have three way speakers and the crossover is external. However, the tweeter and mid crossovers share no common paths (except at the amp) and are independently wired (bi-wired). To confuse the issue a bit more the speaker cable is relatively long compared to the umbilical joining the crossover to the speakers and the bass is actively driven from another amp completely, also via relatively long cable (five metres) but connected directly to just the bass drivers.
I've just came from a bi-wired connection. Used to have 2x2.5mm Van Damme Blue but decided to try 4mm single wire (same VD Blue), with 4mm wire jumpers between the posts. I'm not hearing any difference at all. Then again my speakers have passive crossovers and from everything I've read on the subject, bi-wiring will only give benefits when using active crossovers (which makes sense).
You can't bi-wire as such if you are using active crossovers but you must inherently use separate runs of cable for each drive unit.
There seems to be some confusion amongst contributors as to what constitute bi-wiring, bi-amping and (possibly) active operation.
However, to address the topic, I'm not sure what the actual technical difference is in moving the crossover in this manner. All the signal and return paths stay the same, the only thing that has changed is the cable that goes between the amplifier and the crossover becomes short and the cables from the crossover to the drive units becomes long.
In my own case I have three way speakers and the crossover is external. However, the tweeter and mid crossovers share no common paths (except at the amp) and are independently wired (bi-wired). To confuse the issue a bit more the speaker cable is relatively long compared to the umbilical joining the crossover to the speakers and the bass is actively driven from another amp completely, also via relatively long cable (five metres) but connected directly to just the bass drivers.
This might be of help: http://theartofsound.net/forum/showthread.php?5818-Basics-amp-General-Bi-amping-and-Bi-wiring .
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However, to address the topic, I'm not sure what the actual technical difference is in moving the crossover in this manner. All the signal and return paths stay the same, the only thing that has changed is the cable that goes between the amplifier and the crossover becomes short and the cables from the crossover to the drive units becomes long.
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If there is a technical difference I don't know what it is. I doubt many have tried this for themselves as it is usual to place external crossovers next to the speakers. More to keep them out of the way than anything, I suppose.
Unfortunately it would involve a lot of custom cable making and a load of general 'dicking about' for me to achieve this mod. If I saw some logic to it I would be prepared to go to the effort (as I have all the necessary hardware) but without some technical persuasion (particularly given my non-standard wiring config) I am reluctant to experiment in this area. However, as ever, I remain open to persuasion.
As an electronics expert, I make a good plumber so what about wide band noise getting back from conesī action etc. to the crossover components but down the wires somehow and not only through microphony. As simple as longer length wires means less negative effect ? Do cones retrogenerate electrical noise he says running out to buy 20m extra speaker cable. This would also help explain why sound through my headphones has always been better than through my speakers but the gap is much tighter now. Told you I was a romantic plumber.
Stratmangler
28-04-2016, 15:30
Do cones retrogenerate electrical noise he says running out to buy 20m extra speaker cable
Back EMF?
Arkless Electronics
28-04-2016, 18:33
It's technically no different to bi wiring.
But for some reason sounds a zillion times better.
Hi Mark,
What if you just did a lash up to extend the length of the cables between tweeters and crossovers and mids and crossovers to simulate more physical distance ? By default everyone uses the shortest cables poss. Just to see if you hear something. Yes, I know itīs crazy.
CornishPasty
28-04-2016, 20:22
By default everyone uses the shortest cables poss.
I've tried my IMFs both ways ie long interconnects, short speaker leads and visa versa and I prefer them with long speaker leads. I can also understand the system sounding different (I can't say better as I haven't tried it) with long speaker leads after the crossover. The speaker leads will have a certain inductance and dc resistance and this is now on the output side of the crossover. I'm only surmising of course.
walpurgis
28-04-2016, 20:36
I only actually need about 2.5m speaker leads, but generally use around 4.0m leads. I like a bit of leeway to move speakers and route leads. Can't say I've heard any difference using short or longer leads of similar type.
(by the way. I've come across some great sounding speaker cable. Transparent Audio Musicord. It's not desperately expensive, but it is pretty hard to track down. It's fairly slim and looks like strimmer cable, but really sounds fine. Very open and no harshness at the top. Works wonderfully with my Tannoys. Worth finding)
Isn't the Only relevant factor of a Speaker wire it's Resistance ? Remembering that it's a Power feed.
Presumably the OP had the worst/most resistive wire on the Planet pressed into use as Speaker wires.
Not many other possible explanations that are not into 'betwixt the ears' subjects.
Just to enter the fray, it is NOT a great idea to move external passive crossovers as far from the speakers as possible (ie back to the amp) and there is no "wide band" coupling from speaker "cones" to passive crossovers placed close to speaker enclosures. Too many assumptions being chucked about folks.
The reason you ought to keep external crossovers close (ish) to the enclosures is that the further away you move them, the more chance of altering the voicing because you are unnecessarily introducing a greater length of reactive capacitance and inductance from a filter which should, as far as is practicable, be placed as close to the driver as possible because the whole point of a passive crossover is to act as part of the electrical load on the drive unit to accurately shape the acoustic response to the desired shape and phase alignment. For all practical purposes, just outside the enclosure is usually the best place.
Bi-amping does nothing magic to a speaker's response and the only obvious benefit is that bass damping factor can be improved where you have longer cable runs, but equally, just stepping up to the next cable gauge size does the same thing. In theory, single wiring also offers less crossover distortion by introducing some electrical damping between cone and woofer, depending on the design.
That all said, run with whatever you prefer the sound of as there's no right or wrong, but it is not correct to make assumptions based on assumption or what others have written on t'ut interweb! ;)
Virtual-Symmetry
15-05-2016, 12:27
Why don't people build proper active systems any more? [I don't mean speakers with built in class D power amps]
Arkless Electronics
15-05-2016, 12:42
Why don't people build proper active systems any more? [I don't mean speakers with built in class D power amps]
There are a few about..... Mainly though because hi fi tends to run on what's trendy or "in" at the moment and not on what's the best engineering solution to problems.
There have been a couple of (proper) active systems at the NEBO meets. They were very good.
Just to enter the fray, it is NOT a great idea to move external passive crossovers as far from the speakers as possible (ie back to the amp) and there is no "wide band" coupling from speaker "cones" to passive crossovers placed close to speaker enclosures. Too many assumptions being chucked about folks.
The reason you ought to keep external crossovers close (ish) to the enclosures is that the further away you move them, the more chance of altering the voicing because you are unnecessarily introducing a greater length of reactive capacitance and inductance from a filter which should, as far as is practicable, be placed as close to the driver as possible because the whole point of a passive crossover is to act as part of the electrical load on the drive unit to accurately shape the acoustic response to the desired shape and phase alignment. For all practical purposes, just outside the enclosure is usually the best place.
Bi-amping does nothing magic to a speaker's response and the only obvious benefit is that bass damping factor can be improved where you have longer cable runs, but equally, just stepping up to the next cable gauge size does the same thing. In theory, single wiring also offers less crossover distortion by introducing some electrical damping between cone and woofer, depending on the design.
That all said, run with whatever you prefer the sound of as there's no right or wrong, but it is not correct to make assumptions based on assumption or what others have written on t'ut interweb! ;)
Hi Paul,
The fact remains that my speakers (WD25TEx) and one other pair (WD20T) we tried (funnily enough, both are Peter Comeau aperiodic designs) go lower, higher and give better piano tone etc. with the crossovers close to the amp. I take it this would mean that the crossovers could have been better designed or implemented (more likely) in the first place and the changes are just that - changes and as you say, each to his own.
Virtual-Symmetry
16-05-2016, 18:00
There have been a couple of (proper) active systems at the NEBO meets. They were very good.
What of the Stonehenge variety? :(
Thought about it but nope I don't understand your question
unfairlane
17-05-2016, 07:58
Isn't the Only relevant factor of a Speaker wire it's Resistance ? Remembering that it's a Power feed.
Presumably the OP had the worst/most resistive wire on the Planet pressed into use as Speaker wires.
Not many other possible explanations that are not into 'betwixt the ears' subjects.
Yup, you are right danilo. Most audiophiles have no idea how important this is to a systems performance. Btw;`my speakers are tri-wired and I know why.
The cable I had was the one sold by World Audio as simple OFC cable. I hardly think itīs the worst cable in the world but certainly not the best, I assume.
Do you have a equaliser set up in your system too?
Just a thought but could the length of cable or position of the crossover affect the frequencies to and from the eq causing your speakers to sound different and could the same sound difference be achieved if you tweaked your eq?
Taz
Errr....
what the OP describes is not biwiring. You HAVE to split the signal after the crossover, otherwise you are mingling the frequency divided signal back into one with no crossover! All external crossovers work the same, they take the signal from the amp (single wired usually) and pass it through a crossover which splits the signal to each drive unit. Hence there is no birwiring involved. It happens on internal crossovers where the signal gets split to each driver. Some confusion here methinks.
As for claims of signals from amps to crossovers (nternal or external) being clearer if biwired, well the signal doesn't know it's been bi-wired so each run contains the full frequency signal anyway, therefore the only beneficiaries are cable salesmen. If it does sound better, chances are going up in thickness from your standard cable will have the same effect.
Then there's bi-amping, where the signal from the preamp is split and one or two (stereo or mono) power amp handles the bass (usually one with high damping factor and adequate power) and the other(s) handle the higher frequencies so each power amp has a set of output cables feeding a seperate crossover board for each drive unit (crossever needs to be split for each drive unit usually).
Then there's active, where prior to the power amp (before or with the preamp), the signal is split so that the preamp has outputs for the various frequencies (ie a pre with several outputs linked to internal active crossover boards or in some cases, external to the pre, crossover boards) or multiple pres are used with active boards for each driver.
Confused?..you will be.
StanleyB
09-06-2016, 09:54
Bi-wiring works on more or less the same principle as star grounding, and few would argue against the technical benefits of star grounding. It's funny for me to read some of the comments in this thread. As the designer of possibly the world's only bi-wiring capable speaker selector I have had literally hundreds of customers feedback on the differences that users noticed before and after they tried bi-wiring in their system. I am not claiming that it is the best thing since sliced bread. But all little bit helps when it makes an improvement to our system's performance.
Bi-wiring works on more or less the same principle as star grounding, and few would argue against the technical benefits of star grounding. It's funny for me to read some of the comments in this thread. As the designer of possibly the world's only bi-wiring capable speaker selector I have had literally hundreds of customers feedback on the differences that users noticed before and after they tried bi-wiring in their system. I am not claiming that it is the best thing since sliced bread. But all little bit helps when it makes an improvement to our system's performance.
I have no doubt that some people may hear improvements in their systems Stan, but I would be interested if you could point me to a single technical paper which supplies solid proof that biwiring provides any audible gains, as in measurable. You aren't star-earthing, you're doing the exact opposite by splitting the ground return between the different drivers, unless I've missed the point you were trying to make? I would also seriously question any audible benefits at the voltages in question because even with commoned ground returns, the difference between splitting the grounds and using a common ground would account for less than audible (possibly less than one quarter of one dB in cross-talk) differences. I have looked hard for any discernible benefits and have found none. I'm not the only loudspeaker designer who thinks this way either. That in itself is not concrete proof of anything, but just as you find some of these comments "funny", I reasonably question the technical merits which are often espouced without a single shred of evidence to back them up. I remain fully open minded though and genuinely would be appreciative if you could in fact show me the error of my ways!
Hi Paul,
The fact remains that my speakers (WD25TEx) and one other pair (WD20T) we tried (funnily enough, both are Peter Comeau aperiodic designs) go lower, higher and give better piano tone etc. with the crossovers close to the amp. I take it this would mean that the crossovers could have been better designed or implemented (more likely) in the first place and the changes are just that - changes and as you say, each to his own.
I understand that Chris and in your particular case, the additional loop resistance provided downstream of the filter becomes additive with the drive unit impedance and does alter the crossover slightly, so it could well point towards some tweaks being necessary in the original design, who knows. I would be easily able to determine this though with a relatively simple set of comparative acoustic measurements and some simulation. Pointless in this case as your ears tell you that you prefer the outcome, but generally, my advice is that it is not a great idea to move crossovers too far from the loudspeaker they're meant to be driving as doing so will alter the impedance that the filter sees and needs to drive, albeit only slightly.
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