To terminate or not, that is the question

[garylkoh]

for spades v banana plugs, Gary
Thanks!

No real rationale - just a preference. Amplifiers don't vibrate (or shouldn't) hence the spades which have a better connection at that end. Loudspeakers vibrate, and the spring on the particular banana I like should "seat" better over time and generate a better contact - instead of the binding post nuts going loose and make for a worse contact.

Also, I like bananas at the loudspeaker because it lets me remove the binding post nut on the positive side - if you're coming to RMAF and stopping by my suite after hours I'll demonstrate.

 

[Gregadd]

I put bananas on the speaker so when you trip over the cord it will disconnect when you trip over it.

 

[c1ferrari]

Also, I like bananas at the loudspeaker because it lets me remove the binding post nut on the positive side - if you're coming to RMAF and stopping by my suite after hours I'll demonstrate.

Thanks, Gary...it would require taking time off from work to make RMAF this year. Should I decide to do just that, it would certainly be fine to meet you and the WBF associates.

 

[Dr_jitsu]

I went with the Canare 4s11 and WBT connects (banana plugs) for my front stage....went w/ the cheaper Chinese plugs (but they are still pretty decent quality, and they still are put on over WBT 14k ferrels) for my subs.

I am upgrading my rear surrounds to Klipsch RF-82's (I have RB 51's mounted up high behind them) and I am going to go w/ these ribbon cables (since I run them under the carpet and walk on them occasianally): http://www.ebay.com/itm/Professiona...uting_CablesConnectors_RL&hash=item4841b9ca0e

 

[Orb]

Hmmm... No comment on your choices, Dr_jitsu, but want to briefly sidetrack this thread to ask Gary about banana plugs being better than bare wire in a screw terminal. I read about spades vibrating loose; isn't the same true of banana plugs? (For the record, I have had problems with both in the past, but more with banana plugs so admit my bias.) And, without a really good mechanism for expanding and capturing the banana plug, won't their connection impedance be higher than a screw-type bare-wire connection? At least, I found that to be true in the past, but I am not sure I ever actually measured one of the expanding types of banana plugs that provide more positive capture and retention, and I have not looked recently.

Curious - Don

What would be interesting is the consideration of cleaning contacts or even removing and reconnecting the cable.
It has been commented on by quite a few engineers and a few with scientific backgrounds that after a short while (can be under weeks slow degradation starts) the sound quality can be compromised if the cable is not removed and reconnected/clean termination/connection points.

If using bare wire I would had thought this is more tricky to do with possibility of greater wear.
Cheers
Orb

 

[garylkoh]

As I mentioned earlier, I am not a fan of bare wire for quite a number of reasons.

If you give consideration to the cleaning of contacts - the particular type of banana I use (similar to the ones that Naim uses to terminate their speaker cables) has a sprung piece that is extremely tight. With some binding posts, it can be extremely difficult to insert. Removing and reconnecting it scrapes the contact surfaces and this can result in better sound...... but then again I have not been able to measure the improvement so for the cable non-believers it's probably my imagination.

I believe that for spades, there is much less advantage to removing and reconnecting.... unless the nut has worked itself loose.

 

[DonH50]

Thanks Gary, makes sense. The idea behind any connection is to make it air-tight to prevent oxidation; a tight screw-clamp with bare wire or soldered spade clamped tightly has been my choice but I have not tried any of the new "tight" bananas. It would make life easier at times so I need to look into those.

To satisfy your imagination, while I cannot quote specific numbers after so many years, I have measured contact resistance over the audio band for various connections and it is quite measurable with the right equipment. Including the effect of wiping action on banana plugs. In fact, from an old, dirty plug to the same one cleaned up, IIRC the difference was in the 10 - 100 mohm range of order, enough to change the effective DF significantly. Audibility is always the question, of course, but you can measure it.

 

[Orb]

Yeah,
I think even JJ also feels the degradation within weeks is audible, and he is pretty skeptical of a lot of audio audible related theories.
Seperate to this, much of this can go back to John Curl testing that showed quite clearly measurement effect/degradation after short time, following up on his anecdotal audibility experience relating to cables.
Cheers
Orb

 

[fas42]

I've been banging on quite a bit about getting really good sound, but you haven't got a hope in hell of achieving what I'm talking about unless you sort out these connections properly. Less than 100% perfect connections, for a start, will guarantee that "bad" recordings will always sound bad, even if every piece of your gear costs over $100k apiece. In my experience connections start to go off in a matter of minutes, not weeks, so being sloppy here also guarantees the vast majority of the money spent on getting better sound is being wasted ...

Frank

 

[microstrip]

Thanks Gary, makes sense. The idea behind any connection is to make it air-tight to prevent oxidation; a tight screw-clamp with bare wire or soldered spade clamped tightly has been my choice but I have not tried any of the new "tight" bananas. It would make life easier at times so I need to look into those.

To satisfy your imagination, while I cannot quote specific numbers after so many years, I have measured contact resistance over the audio band for various connections and it is quite measurable with the right equipment. Including the effect of wiping action on banana plugs. In fact, from an old, dirty plug to the same one cleaned up, IIRC the difference was in the 10 - 100 mohm range of order, enough to change the effective DF significantly. Audibility is always the question, of course, but you can measure it.

Did you check if this difference had a linear behavior? I have read that sometimes these poor contacts are characterized by a non constant DV/DI (non ohmic behavior) .

 

[DonH50]

Had a long post and lost it, durn MS update reminders!

I have seen at least a couple of things that can cause the resistance to act a bit strangely:

1. Dissimilar metals and/or oxidation can cause quasi-semiconductor (e.g. Schottky diode) effects, a nonlinear phenomenon; and,
2. The oxidation can cause the resistance to vary with current and frequency.

I am not a materials guy so have to defer on explanations (I have friends who are). Any signal-dependent effects potentially cause distortion.

Audio adds vibration, which can cause the resistance to vary with the signal via mechanical movement of the connection.

HTH - Don

 

[garylkoh]

Hi Don,
Thanks. Some of this I've measured, even with rudimentary equipment. However, due to the magnitude of the differences, FR and distortion differences are extremely minor. I've measured different bananas to differ in the range of 10 mOhm to 30 mOhm. But the argument is that with a speaker impedance of 8 Ohms, the difference is not audible. Given the how different the various bananas can sound to my ears, I'll keep the ones I like to myself, and let the objectivists tell me that it's my expectation bias or my imagination and refuse to get drawn into these arguments. I think that we've conclusively proven in an earlier thread that well-designed cables cannot matter.

 

[fas42]

And another of the bits of wacky audiophilia is that people obsess over the level of silver in their super special solder on the other side of a connection where one piece of grubby metal is hanging on for grim life to another piece of grubby metal. Imagine if Formula 1 engineering used this type of engineering rationale ...

Frank