# CMC binding posts



## robh (Mar 24, 2009)

I found these to be not terribly expensive, so I was wondering what the opinions of CMC connectors in general, and their copper binding posts specifically, are.

Thanks


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## Anthony (Oct 5, 2006)

I haven't used them, but they look like a lot of OEM stuff I see on amplifiers and receivers.

didn't see prices on the site, though, so I couldn't comment on the relative value.


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## robh (Mar 24, 2009)

Thanks. I decided that since I can replace the binding posts on my all Polks for just over a $100 US, it's relatively cheap as audio experiments go, and won't take a lot of work to do, either, I'm just going to try it. That's usually what it comes down to, anyway. I'll do a post after I get them installed and let people know. They'll be replacing the gold plated brass posts the Polks come with. Since they're red copper, I'm assuming it's pure copper with zero zinc or tin.

I managed to locate their site. Looks like the stuff is coming out of Taiwan. Not quite as good as if it came out of the US, but probably decent. I was mainly worried about it coming out of China, as that stuff is real hit or miss on quality.


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## robh (Mar 24, 2009)

Posts got here Friday. I'm going to try to get them installed in a few speakers today and see if I can tell any difference. I got the "red copper" version. I'll be treating them with Deoxit inside and out. I'll post once I have some put together and do some listening.


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## robh (Mar 24, 2009)

Or not... looks like this is going to be more work than I thought, and I don't want to get into it today. But the short of it is that these posts are larger diameter, so I'm going to have to rework the cross overs a bit to make these fit. I also need to find some copper round terminals to use in place of the nickel or tin or whatever they have soldered into the cross over.


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## Kenobi (Aug 11, 2010)

Hi Rob and all,

I am new and just thought I respond to provide my impression--however limited. I replaced my binding posts for a pair or ELT525M along with internal wiring swap, by-pass caps added and sound dampening (no-rez/black hole variant) and aluminum terminal plates. Since I did all of the above at once, its really hard to isolate or give credit to any one change as they all contribute their fair share. I would say that, overall, the results were better than expected. If the CMC binding posts contribute on par with any of the above mentioned, I think it is doing an awesome job. The speakers were transformed from a shy, wall-flower, inarticulate and indistinct to an articulate, singing machine that's clear, clean, fresh and alive-sounding. It took at least 24hrs on the Isotek burn-in CD to achieve the results mentioned however. Prior to that, I thought I made a mistake and wasted time, money and effort. I must say that these posts must have done its part to contribute to this overall, very satisfactory result.

YMMV,

Kenobi


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## Seaxe (Sep 13, 2008)

G'day robh, FWIW, I have found solid high conductivity copper binding posts sonically superior to gold plated brass in every respect. I cannot comment on CMC brand, as I make my own in my brothers machine shop. As a practical experiment, those folk with bi-wireable speakers still fitted with gold plated brass fittings connecting the two sets of posts, replace the brass strips with 12G stranded copper wire. Play some music, and useing your amps balance control, listen, one to the other. For myself, I have found c opper beats gold/brass every time. Depending on other factors, the improvement may be small to marked. In any event, I am a fan of copper over other metals as I percieve sonic improvements due to its employment. YMVV, but the cheap and easy experiment mentioned may serve to convince some. Cheers, Mike.


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## Seaxe (Sep 13, 2008)

Ooops, my fondness of the grape is addling my courtesy! A big welcome to you Kenobi, I am sure you will find the Shack a great resource, with some of the most helpful and friendly people on the"web". Congatulations on succesfully tweaking your speakers, its often an ear opening experience, coupled with the satisfaction of doing it yourself. Cheers,Mike.


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## robh (Mar 24, 2009)

Seaxe said:


> G'day robh, FWIW, I have found solid high conductivity copper binding posts sonically superior to gold plated brass in every respect. I cannot comment on CMC brand, as I make my own in my brothers machine shop. As a practical experiment, those folk with bi-wireable speakers still fitted with gold plated brass fittings connecting the two sets of posts, replace the brass strips with 12G stranded copper wire. Play some music, and useing your amps balance control, listen, one to the other. For myself, I have found c opper beats gold/brass every time. Depending on other factors, the improvement may be small to marked. In any event, I am a fan of copper over other metals as I percieve sonic improvements due to its employment. YMVV, but the cheap and easy experiment mentioned may serve to convince some. Cheers, Mike.



Ah, you're a lucky bastard... a brother with a machine shop. I'd give body parts, and important ones too, for such a wealth.

I still haven't even gotten started on this project. I got some 1/8" OFC copper plate to make the plates to mount the posts in, but it turned out to be too difficult to work with give the meager selection of tools I have. Ended up with some OFC copper sheeting, which should be easier and will let me make a single solder connection from the plate into the xover. Now I just need work to slow down so I can actually take a few days off and get this done, since in studying the problem, I'm going to have to completely remove the xovers and disassemble them to do this modification. They tell me October for new people now, but they've been telling me "in 2-3 months" for most of the last year and a half, so I'm not particularly optimistic. What I am, though, is glad that I still have a job and haven't had to take a pay cut in this economy.


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## Seaxe (Sep 13, 2008)

No worries mate. Remember that binding posts must be electricaly isolated from whatever they are mounted on.Save the expensive copper sheet for projects needing shielding,or ground planes, or front panel "bling". Aluminium, or even wood or mouldable plastics (like Kydex) are often more suitable. My earlier post mentioning "high conductivity copper" may need added clarification. This is an industry term for high thermal conductivity, as opposed to "machinable copper". However, thermal conduction and electrical speed are closely related,so "high conductivity" copper is vastly prefered for sonic reasons, it is also somewhat soft, and more care (slow speed), is required to machine it. Non ferrous metal merchants will supply you various billet sizes for your needs. Cheers, Mike.


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## 1Michael (Nov 2, 2006)

If you are going to do a side by side comparison, then you must change the signal to Mono, or regardless of what you are comparing, you are gong to hear a difference in sound...because there are different sounds coming to each speaker...which would negate the comparison...


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## looneybomber (Sep 20, 2006)

Heh, I don't even notice a difference when I bi-amp my speakers, so there's no way I'd hear a difference if I used OFC wire vs. a jumper.


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## Kenobi (Aug 11, 2010)

Seaxe said:


> Ooops, my fondness of the grape is addling my courtesy! A big welcome to you Kenobi, I am sure you will find the Shack a great resource, with some of the most helpful and friendly people on the"web". Congatulations on succesfully tweaking your speakers, its often an ear opening experience, coupled with the satisfaction of doing it yourself. Cheers,Mike.


Thanks for the warm welcome, Mike. Appreciated. I've been into this hobby for close to 20yrs and have tried various things to improve a system. I've been successful with some and not so with others. Therefore, I think I have a good grip of what's real improvements vs snake oil. Nevertheless, I am always out to do more trial and error in the quest to improve my set up.

In the above case, I did the mod on one speaker first and was about to reverse it due to a drop in efficiency that sounded like I had a blanket over it when the parts weren't burned in (another subject of controversy for some). However, I was actually pleasantly surprised how good it sounded compared to the original stock after break-in. It literally only looked the same on the outside but sounded totally different in character. 

Previous to this, I also swapped out RCA input jacks from my Nuforce amp for the CMC copper ones. It took a long time but eventually, I have no more high-frequency fatigue/harshness that was a part of my system for a time. Yet, the details are still all there, just more pleasant and enjoyable, smoother and easier on the ear. 

Lastly, regarding the other gentleman's remark about bi-amp, I run my center speaker bi-amped. I had no doubt about its increased slam and control factor for HT use vs regular non-biamp. YMMV.

Best regards,

Kenobi


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## bambino (Feb 21, 2010)

looneybomber said:


> Heh, I don't even notice a difference when I bi-amp my speakers, so there's no way I'd hear a difference if I used OFC wire vs. a jumper.


I never could tell a differance either untill i went to outboard amps and Bi-amped them, there is deffinatly more there then when i was trying to Bi-amp just using my AVR's amps.:T


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## looneybomber (Sep 20, 2006)

bambino said:


> I never could tell a differance either untill i went to outboard amps and Bi-amped them, there is deffinatly more there then when i was trying to Bi-amp just using my AVR's amps.:T


Yeah with my AVR, I can measure that I am drawing more power from the wall socket (kill-a-watt type thing) but I can't a difference. However, AVR vs my EP2500, there's a difference


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