• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Bi-Wiring without Bi-Amping

MediumRare

Addicted to Fun and Learning
Forum Donor
Joined
Sep 17, 2019
Messages
852
Likes
899
Location
Chicago
#1
My speakers have two sets of binding posts and both the manufacturer and reviewers have recommended bi-wiring them. (The speakers do come with jumpers to bridge the binding posts in case of not being able to bi-wire them.)

I think one reason is that the tweeters and mid-range are rated 8 ohms, while at very low bass the impedance drops to perhaps 3 ohms. I have a Mac 200 watt amp with 2, 4 and 8 ohm taps - I currently use the 4 ohm taps in a single wire configuration as the amp runs cool, while using 8 ohms it got a little hot when run at higher output levels.

My question is: Should I bi-wire the speakers from the same amp using two sets of positive posts and returning to the same ground?
 

Webninja

Active Member
Forum Donor
Joined
Oct 8, 2018
Messages
141
Likes
125
Location
Los Angeles
#2
From what little research I did, bi-amping makes sense, but bi-wiring does not. I didn't find any non-subjective documentation about bi-wiring.

I did try it on my speakers and I didn't notice any improvement when I bi-amped vs the jumper. Did not do any proper testing though.
 

KozmoNaut

Active Member
Joined
Sep 28, 2019
Messages
299
Likes
513
#3
To get any real benefit from bi-amping, you should bypass the crossover in the speaker, and use an active line level crossover before the amps. Effectively making passive speakers into active speakers.
 
OP
MediumRare

MediumRare

Addicted to Fun and Learning
Forum Donor
Joined
Sep 17, 2019
Messages
852
Likes
899
Location
Chicago
Thread Starter #4
To get any real benefit from bi-amping, you should bypass the crossover in the speaker, and use an active line level crossover before the amps. Effectively making passive speakers into active speakers.
Wouldn’t the speaker mfg have managed that when they set up to separate inputs?
 

DonH56

Technical Expert
Technical Expert
Forum Donor
Joined
Mar 15, 2016
Messages
4,179
Likes
6,363
Location
Monument, CO
#5
Wouldn’t the speaker mfg have managed that when they set up to separate inputs?
No. The terminals split the high-pass and low-pass sections of the crossover but do not bypass them. The crossover is still inside and in the signal path, just in two pieces.

If you want to bi-wire you can but it probably (almost certainly unless the wire gauge is much too small) won't do anything. Try it and see; wire is cheap, but remember expectation bias is strong... If the wire size is too small it may help, but since the bass section is lower in impedance and usually takes the most power anyway (see e.g. https://en.wikipedia.org/wiki/Equal-loudness_contour and notice how bass much be much louder for us to hear the same loudness as in the midrange), you'd be better off wiring the two cables in parallel (connect but leave the jumpers in place). Or just buying larger wire (single pair, larger gauge).

FWIWFM - Don
 

Kal Rubinson

Major Contributor
Industry Insider
Joined
Mar 23, 2016
Messages
1,897
Likes
2,299
Location
NYC/CT
#6
Wouldn’t the speaker mfg have managed that when they set up to separate inputs?
Of course but not necessarily with the intent that you assume. More than one speaker manufacturer has told me, in confidence, that they went from a single pair of terminals to a dual pair ("suitable for bi-wiring") specifically in response to requests from their dealers who want to sell more cables. They even modified the user's manual to "suggest" that users might prefer bi-wiring. FWIW.
 

oivavoi

Major Contributor
Forum Donor
Joined
Jan 12, 2017
Messages
1,436
Likes
1,040
Location
Oslo, Norway
#7
Of course but not necessarily with the intent that you assume. More than one speaker manufacturer has told me, in confidence, that they went from a single pair of terminals to a dual pair ("suitable for bi-wiring") specifically in response to requests from their dealers who want to sell more cables. They even modified the user's manual to "suggest" that users might prefer bi-wiring. FWIW.
Makes sense to me.

On a similar note, given that I mostly don't eat meat I've sometimes communicated with producers of vegetarian replacement "meat". Some of them are touting that their products are "SOY FREE!" or "NO SOY!". I've asked them: Why? Given that there's no credible research which suggests that soy consumption has negative effects on people, quite the opposite actually, and that we know that soy is the most complete non-animal protein? Many of them have then admitted to me that well... personally they don't think soy is bad, and for the sake of the nutritious value of their products they would have liked to include it... but this is what consumers want.

Markets are not always rational, neither in hifi nor in other areas.
 
OP
MediumRare

MediumRare

Addicted to Fun and Learning
Forum Donor
Joined
Sep 17, 2019
Messages
852
Likes
899
Location
Chicago
Thread Starter #8
Of course but not necessarily with the intent that you assume. More than one speaker manufacturer has told me, in confidence, that they went from a single pair of terminals to a dual pair ("suitable for bi-wiring") specifically in response to requests from their dealers who want to sell more cables. They even modified the user's manual to "suggest" that users might prefer bi-wiring. FWIW.
Does this help? Not the exact schematic, but let's assume for now it is).
https://www.usaudiomart.com/details...ete_heads_with_crossovers_read/images/735760/
 

Soniclife

Major Contributor
Forum Donor
Joined
Apr 13, 2017
Messages
2,885
Likes
2,739
Location
UK
#9
My question is: Should I bi-wire the speakers from the same amp using two sets of positive posts and returning to the same ground?
You are wanting to use the 4 ohm and the 8 ohm taps at the same time? That sounds like a bad idea to me.
 
OP
MediumRare

MediumRare

Addicted to Fun and Learning
Forum Donor
Joined
Sep 17, 2019
Messages
852
Likes
899
Location
Chicago
Thread Starter #10
You are wanting to use the 4 ohm and the 8 ohm taps at the same time? That sounds like a bad idea to me.
Yes, that was my thought, otherwise the effect would just be more capacitance and less resistance, right?
 

Soniclife

Major Contributor
Forum Donor
Joined
Apr 13, 2017
Messages
2,885
Likes
2,739
Location
UK
#11
Yes, that was my thought, otherwise the effect would just be more capacitance and less resistance, right?
I'm not the best person to answer but that sounds like different amounts of power would be sent to the 2 drive units.
The simple answer is biwire is only of benefit to one group, the ones selling you the wire.
 

graz_lag

Major Contributor
Joined
Oct 13, 2018
Messages
1,296
Likes
1,443
Location
Le Mans, France
#13
I did exactly as posted by @DonH56 so running larger gauge (AWG 12) to the LF terminals and a smaller one (AWG 16) to the HF ones.
Subjectively, I feel this solution more pleasant over the one with the same gauge on both terminal pairs.
 

Blumlein 88

Major Contributor
Forum Donor
Joined
Feb 23, 2016
Messages
8,957
Likes
11,591
#14
DonH56 knows more than me. And I would have written pretty much what he did anyway.

Bi-wiring really doesn't help anything. Bi-amping might.

The difference in your case is I believe your McIntosh amp has an autoformer (assuming it is a solid state model).
1572462793378.png


There might be some complex interaction between connecting two frequency dependent loads onto two different taps.

The simple way to look at an autoformer is each tap represents a different level of max voltage, and max current. Higher taps are more voltage, and less current. Lower taps are less voltage and more current.

So connecting your mid/tweeter to 8 ohms would be a higher voltage and less (though sufficient) current. It would be about like turning up the mid/tweeter by 3 db relative to the woofer. So in this case it would likely sound different. It would be a different balance than the speaker maker intended. Unless you want to alter the frequency balance of your speaker, I'd use a single sufficient cable running off the 4 ohm tap. But I don't think you will blow up anything if you want to try it.
 

DonH56

Technical Expert
Technical Expert
Forum Donor
Joined
Mar 15, 2016
Messages
4,179
Likes
6,363
Location
Monument, CO
#15
I think I misunderstood the OP's intent if the plan was to use two different output taps. You do NOT want to load both taps of the output autoformer. That could cause problems, and while may not break anything, if the internal circuits are not isolated you may create an unintended short-circuit that takes out the amp. It could cause the amp to run hot, or just change the sound as @Blumlein 88 said, but I would not do that. Use the 4-ohm tap as you are now and connect both pairs of wires to it, then one pair to the high input and one to the low input on the back of the speaker. Make sure the polarity is maintained for both sets of wires when connecting, and that you do not short the amplifier's output. You can remove the bridging strap on the speaker if you bi-wire.

For the record, I do not think it will help, and if it does anything at all you'd would be better just connecting both to the bass terminal and leaving the jumper. The premise of bi-wiring is to use the wires to "isolate" the tweeter from the woofer so back-EMF from one does not get into the other. That only makes sense if the amplifier's output impedance is very low (most are) and wire resistance fairly high (most are not and you really do not want them to be). My view is the effect might be measurable under certain rather extreme conditions but is not audible.

Bottom line: I would not bi-wire in this case, but if you try it just use the 4-ohm output tap for the connections.

FWIWFM, YMMV, etc. - Don
 

LuckyLuke575

Senior Member
Forum Donor
Joined
May 19, 2019
Messages
326
Likes
273
Location
Germany
#16
My speakers also have 4 terminals on the back, but I'm scared of breaking them if I bi-wire them :(

My stereo amp has 4 outputs that I can run simultaneously, but I'm not sure what benefit this would have, because I already have plenty of power to drive the speakers.
 

Julf

Major Contributor
Forum Donor
Joined
Mar 1, 2016
Messages
1,536
Likes
1,704
Location
Amsterdam, The Netherlands
#17
My speakers also have 4 terminals on the back, but I'm scared of breaking them if I bi-wire them :(

My stereo amp has 4 outputs that I can run simultaneously, but I'm not sure what benefit this would have, because I already have plenty of power to drive the speakers.
Those kind of outputs are usually connected in parallel (so two pairs of 4 Ω speakers would result in a 2 Ω load), but amps with output transformers/autoformers (tube amps and MacIntoshes) are slightly different.
 
OP
MediumRare

MediumRare

Addicted to Fun and Learning
Forum Donor
Joined
Sep 17, 2019
Messages
852
Likes
899
Location
Chicago
Thread Starter #18
For the record, I do not think it will help, and if it does anything at all you'd would be better just connecting both to the bass terminal and leaving the jumper.
Thanks, I think I will just leave as-is on the 4 ohms taps just as you described.
 

anmpr1

Major Contributor
Forum Donor
Joined
Oct 11, 2018
Messages
1,455
Likes
2,073
#19
In the latest News from the Moronosphere, McIntosh Labs have moved on from yesterday's bi-wires. Their $80,000.00, 1000 watt monophonic amplifier sports terminals for tri-wiring. That's one more than bi-wiring, for those who are counting. My obvious question was why they didn't pull out all the stops, and go for quad-wiring? Since this had been worrying me, and since I hadn't read anything from Darko or What Hi-Fi about it, I decided to do some independent investigatory work, and phoned McIntosh support. I was fortunate to reach Mactavish Mcfool, product engineer and marketing maven (known as the Big Mac by his Binghamton colleagues), who took time from his busy schedule to explain it all to me.

McFool said that while it might seem more symmetrically intuitive to go with four hook-up wires, their in-house listening tests (done after a late night candle light Ouija board session, where they attempted to call up the spirit of Frank McIntosh and Gordon Gow, but whose spirits refused to show up for unknown reasons) validated the ancient saying, omne trium perfectum: everything that comes in threes is perfect. He then explained the religious nature of tri-wiring: how the tri-wire can represent not only the Hindu Trimurti, but also the Christian Trinity, thus confirming the spiritual wholesomeness of the triwire schema. Not only that, but the Big Mac told me how everyone knows that "the third time is the charm."

I said, "Yes... I see. But what about the idea that 'three strikes and you're out'?" Or 'bad news comes in threes?' Or 'three's a crowd'. Wouldn't those technical theorems argue against tri-wiring?" McFool thought about it, and admitted as much, but then told me how everything in high-end audio is a trade-off. However, he hinted that the top-secret Mac Skunkworks are devising a new Quinto-Wire half-mono amp (requires two dedicated amps for mono--one amp for each half of the waveform) that will make even tri-wiring obsolete, and skip the quad-wire debate altogether. It should sell for less than $200,000.00. The downside is that you will need four for stereo, and five times the hook-up wire. But in return you'll definitely get audio Nirvana. And blue meters. Four of them... one per amp. Each meter will cover half of the waveform, so you'll really be able to tell what's going on with your system.

Well...after hearing it, that convinced me. I mean, who can argue with science?

MC2KW Output Module Back.jpg
 
OP
MediumRare

MediumRare

Addicted to Fun and Learning
Forum Donor
Joined
Sep 17, 2019
Messages
852
Likes
899
Location
Chicago
Thread Starter #20
Well...after hearing it, that convinced me. I mean, who can argue with science?
Do you not agree that the amp that ideally drives a subwoofer would be a different design from the amp that ideally drives tweeters?
 

Similar threads

Top Bottom