To Bi-wire or not?


I was using Tara Labs shot-gun cable to connect my Usher speakers, leaving the jumpers in. When I switched to Blue Jeans cable and true bi-wire and removed the jumpers. I hear no improvement, in fact i lost some bass. I contacted Blue Jeans to see about cable burn-in but they said burn-in is a myth. I have heard that bi-wiring a speaker with low end cable is better than using higher quality cable in non bi-wire application. Any thoughts?
tbromgard
welcome to a feature that (on many speakers)should have been done way with a decade ago.
when i bi wired my infinity renaissance 90's i ran into the same problem that Tbromgard had, bass loss, i thought that my speakers also sounded better with a single wire too.
greg
You've changed two things at once (cable type, and bi-wiring instead of single-wiring), which makes it hard to provide a meaningful response. I suggest that you try the Blue Jeans cables single-ended, with the jumpers in place, preferably with the high and low frequency wires in parallel, or if that is not feasible then using the low frequency wires and leaving the high frequency wires unconnected.

Bass performance can be compromised by some combination of high cable resistance per unit length (i.e., too small a gauge, meaning an AWG number that is too high), long cable length, low speaker impedance, and/or high amplifier output impedance. Let us know as many of these parameters as you can, and we'll be in a better position to help.

You'll also be interested in the following current thread:

http://forum.audiogon.com/cgi-bin/fr.pl?cspkr&1247016622

Regards,
-- Al
well guys, i wanted to try an experiment, i also have a pair of infinity kappa 9's and we all know how hard they are to run, so for the first time i tried to bi wire them to see if it has something to do with low impedance speakers, when bi wired they sound like you do not have the 4 twelve inch woofers connected (no bass at all) and when they are connected using the single wire bass galore, so i think that it must be a current thing, the amps i am using are two adcom 565 mono blocks, i wonder what is happening.
greg
Hi Greg -- How long are the cables? What is the gauge of the wire used in the single-wire configuration? And what is the gauge of the wire which carries the low frequencies in the bi-wire configuration?

Regards,
-- Al
Tbromgard, as you using two seperate cables per speaker?
If so, are you sure that the connections are in correct polarity at the amp and the same at the speakers?
Also, I find it very helpful to make sure that the routing of the cables is as direct as possible without too much parelleling if possible.
hi Al, i am using 2 identical sets or pairs of wires, 12 gauge and 6 feet long.
greg
Two 12 AWG cables would be the equivalent of one 9 AWG cable. At 6 feet long, that is huge overkill. I just don't see how you could be losing any bass. But of course, there's no harm in sticking with your single wire cables.

If you want to tie this down, you could use a Radio Shack SPL meter plus a program like SynRTA or Room EQ Wizard to actually see what your bass response is.
Bi-amping with external x-over is only reason speakers should have two sets of taps.Amazing what a hustle bi-wiring has been with $250 speakers to $25K is and the general B.S. on wire.Blue Jean was good choice.It has always been like those really thin disc candy on your stereo cake not even real sprinkles (isolation or power conditioning).No way is it frosting let alone the cake.Well made cables make sense and on rare situations where some taming is needed (Cardas with Krell??).But think about NHT.Used those blocks to roll off highs and lows and accentuate mids so people who drop a packet go "Ooooh" and "Ahhh" when in fact they are getting less information but accentuated mids make you think your getting more.Blue Jean single and maybe jumpers made of same wire.Low end Kimber has always been deepest I'd go.Know this is off and widening topic but it has always pissed me off as snake oil as percentage of what some folks spend.
Chaszz
i am ahead of you on this one, i have a rabos system from my infinity preludes that i used to have, it measures the frequencies from 20 to 100hz for the sub for that system, on average there is a 1 to 2db drop on all frequencies from 20 to 100hz when the speakers are bi wired as compared to one single wire, i know 1 to 2db is not much but when i listen and compare a single wire to a bi wire setup, the bi wire setup sounds like less bass.
greg
Well, if you can measure a drop off of 1 dB below 100 Hz, that's pretty definitive: there's something wrong with your bi-wire cable, go back to the old cables. Perhaps there's some issue with the connectors.

I still think the explanations for bi-wiring being supposedly superior sound like bafflegab to me. But I wouldn't expect it to be *inferior* to the point where frequencies below 100 Hz would drop compared to frequencies above.
how could there be an issue with the connectors when i am using 4 new pieces of all the same wire, there can't be an issue with the connectors only when bi wired and not when single wired, it doesn't make sense, also other guys are reporting the same thing too (lack of bass), all our connectors can't be having the same issues, it's just strange, i don't know whats going on here.
greg
From my experience, all the speakers I owned benefited from bi-wire. To me the effect was the sound opened up, bass and treble each got their own feed which allowed the signal to be separated by frequency IE- Highs and Lows are separated which freed up the signal to the drivers. This is just my observation

Speakers I bi-wired with vs jumper
Spendor SP1/2e
Eminent Tech LFT 8a
Magnepan MG3.6
B&W 801 III
Revel F52
regardless IF a change is better or worse, there usually is a change in the sound by using either an acutal bi wired speaker cable, or going with shotguns, twin runs of same cabling.

The idea of Blue Jeans saying what they did is about their perspectives on wire in general.

I'm thinking they are a bit off on that no need for breaking business they told you. I've yet to find a cable of any sort which did not need time with signals flowing through them to improve.

I have found too that wires do have an influence on different areas of the spectrum... some are more bottom end oriented, some aren't. new or otherwise... high priced or low. they're like clothes. They might look great, and have a nice price tag on them, but if they don't fit you, why buy them.

If someone says "wire is just wire" and/or "wires don't need run in time", and you feel differently, just move on. It's a waste of time and energy to tell them otherwise.
Okeeteekid -- I looked into the Kappa 9's a bit. As you realize, but others may not, and assuming that you are using the "extended/normal" switch in the back in the "extended" position, at bass frequencies they are perhaps the most difficult speaker load ever devised by mankind.

In that mode, which seems to be the one most commonly preferred, they go down below 0.8 ohms at some bass frequencies, causing them to be widely known as amp killers.

Your 12 foot round-trip run of 12 gauge wire has a resistance of only about 0.02 ohms, which is negligible even in comparison to the 0.8 ohms. But I calculate that approximately 0.2 ohms of resistance anywhere in the path would result in a 2db bass loss. You shouldn't have that much resistance if all of the joints between cables, terminations, jacks, etc. are well-made and are not oxidized, but when we are dealing with such low levels of resistance being significant, who knows?

In any event, considering how uniquely difficult that speaker is in the bass region, I would not make any generalizations from your observations about bi-wiring that are applicable to anything other than your own setup.

Regards,
-- Al
hi al, just did the same test using the renaissance 90's that are not as difficult to run as the kappa 9's and i still get a 1db drop from 20hz to 100hz slightly less than the kappa 9's 2db, i still think it has something to do with current, i have all infinity speakers that are mostly hard to run, i have a pair of infinity towers that i use for ht i think they are 6 ohms i will try the test on them to see what happens.
greg
Okeeteekid,

Here's a theory I just thought of: You are not really losing bass in the bi-wire configuration; you are just getting better bass damping (meaning tighter, more well-controlled bass), for reasons I'll explain below. That would very conceivably produce the slight measured loss in bass response that you have found (I presume using test tones), and on musical material could very conceivably produce a subjective impression of less bass.

The reason that may be happening is as follows:

In the bi-wire configuration, back-emf from the low frequency drivers is conducted directly (and only) back to the amplifier, which in your case has an extremely good damping factor (i.e., an extremely low output impedance). So the back-emf is absorbed there very effectively.

In the single-wire configuration, some small fraction of the back-emf from the low frequency drivers is conducted through the jumpers into the mid-frequency drivers, where it will not be effectively damped (because the impedance is much higher than at the amplifier output), and, more significantly, WHERE IT WILL PRODUCE SOUND THROUGH THE MID-FREQUENCY DRIVERS, ADDING TO THE SOUND PRODUCED BY THE LOW FREQUENCY DRIVERS.

So you may indeed be getting measurably more bass in the single-wire configuration, but bass which is the result of back-emf effects and is therefore less accurate!

Regards,
-- Al
Al, you may be right, anyhow on my infinity's it just sounds better with a single wire and it may be because the infinity's are on the bright side and the bi wire makes them sound even brighter or slightly more detailed, i was gonna run the bass test on my infinity ht towers but there is no option to bi wire them.
greg
Don't quote me but on this but it maybe related to your question. I read back somewhere in a interview with Cardas that you want to run the smallest gauge possible( just above the min.) that is required by your speakers otherwise bass can be effected.

9 gauge is pretty big but not out of hand.

Your ears are the final truth, if single wire is the best way for your system, by all means stick to it.

Take all of this with a grain of salt but the only way to get a much better answer is try different Bi-wire cables and perhaps an amp but Right now it just apples & oranges.