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[Barry Hufker]

In case I didn't make it clear (and I don't think I did), the person contributing this information is Bruno Putzeys, who I would take to have at least some expertise given his ability to quote the AES document and his general experience with the very technical side of audio gear.

Barry

[Andy Peters]

Barry Hufker wrote on Sat, 23 June 2007 07:19

What I find about the Accusound is that it sounds maybe a bit less nasal and possibly more open.  But I feel as tho' it smears sounds together.

I don't see how this test can be truly fair.  The speaking voice (if that's your test signal) will never be identical for all iterations of the test.  You can't clamp the speaker's head into a test jig, and you can't ensure that the voice tone remains constant.

-a

[Barry Hufker]

Andy,

For me it's not about being "fair".  It's about what I heard no matter how imperfect the test.  This is what I posted earlier.  Everyone must judge for themselves when presented with something new.  You listen to the new thing.  You listen to what you have.  You are unbiased to the extent you can be and then you make a decision to buy or not.

I am *not* claiming a scientific test, nor am I aiming at creating a standard for others as to how they should approach their testing and purchasing.

Testing this new cable has been a journey Klaus has been kind enough to let me chronicle here.

Barry

[maarvold]

Barry Hufker wrote on Thu, 05 July 2007 21:51

...It's about what I heard no matter how imperfect the test.  This is what I posted earlier.  Everyone must judge for themselves when presented with something new.  You listen to the new thing.  You listen to what you have.  You are unbiased to the extent you can be and then you make a decision to [use it] or not...

The analogy for many self-improvement manuals is (loosely quoted) "you are like a guided missile: zig-zagging toward your goal, correcting your course with ever smaller maneuvers as you home in on the target".  
This is certainly what I do: attempt to weed out (and never repeat) the negative experiences and try to build upon and/or recreate the positive ones.  Isn't this why many here seem to like transformers: because they often like what they hear when a transformer is part of the signal chain?  

[HockeyMike]

"Ground conductor and shield go to pin 1 of XLR and to the metal connector's solder lug provided for this purpose. On most connectors this ground/shield lug is a metal loop which has conductance to the connector's shell."


Klaus, sorry if this is a basic question, but how are you connecting the ground conductor and shield to both pin 1 and the solder lug? Dividing up both the shield and the ground conductor wire into two segments? The ground conductor on GAC-3 just seems so thin, being 24 AWG.

Thanks,
Michael

[Klaus Heyne]

I am sorry that I did not make that clearer:

Gotham suggests to connect both ground lug and connector shell lug by dividing the dual Reussen layer of copper strands into two- one to each lug, and the ground conductor to pin 1. That way, they all have the same ground potential in the end.

I normally don't go through that much trouble, and solder to whatever lug is bigger the fat dual-layer of copper shield, and the cable's ground conductor to pin 1 of XLR.

The important issue is to make sure that you jumper between XLR pin 1 and shield lug.

[Barry Hufker]

When I was doing research on this subject, I started a thread that still continues here:

http://recforums.prosoundweb.com/index.php/t/18221/5149/

Barry

[Andy Simpson]

I spent some time today with a test inspired by this thread.

I have generic mic cables in the workshop where I test my mics. Having followed this thread with some interest I decided to go straight to the next stage, which involved putting one of my mics directly into the pre-amp i.e., stuck into the back, with no cable.

With one mic straight into the pre and the other into a gain-matched channel via my usual length of cable for orchestra (approx. 100ft). The mics were basically matched and sound identical usually - which I checked before the test.

I tested with an 8 bell tambourine - at a distance of approx. 10ft - because I always find that basic impulse response is well tested by the individual sounds of each bell and how much natural separation, life & 'dynamic freedom' (the opposite of the sound of compression) there is.

After I gain matched the output of each mic (there was a gain loss from the cable) I did an a/b comparison on loop of a small section.

I was hoping not to find a (great) difference, but I have to admit that it was a disturbingly large difference in this test.

The difference I would describe as extra resolution or clarity.

Further, no amount of eq could bring back this resolution (it reminded me a little of the muddying that tape does).

There was also a gain of ~3dB for going without cable, so noise floor also gained.

I will be making some heavy duty mic stands for my pre's before I set foot in the concert hall for my next recording session and I will run the long runs at line.

This is not a scientific test.
The pre-amp, cable length & mic in question will no doubt affect the results massively.

However, for anyone who can trust their ears, I strongly recommend this test. It is not a subtle thing.

Andy

[Andy Simpson]

Addendum:

I just repeated the test with snare drum and then nylon string classical guitar. Both from 5-10ft.

Snare was much clearer & more dynamic and guitar was much cleaner & more alive.

On the guitar especially, I noticed a huge improvement where the resonances of the body/strings were much more clearly audible and (please forgive my 'audiophile' style description) the sound was more engaging & realistic.

I can only imagine what this will do to an orchestra recording. I can't wait to make the a/b because I suspect that in stereo these differences will be multiplied (as has been my experience with other mic resolution issues in the past).

Again, I would urge anybody to try this test (with plenty of pre-amp headroom).

In most cases, the microphone output xlr can easily be unscrewed & pulled slightly out to allow direct connection to pre-amp inputs.

Andy

[Klaus Heyne]

I recall, this "test" has come up in past threads and articles on mic cables.

Only problem: The test is not realistic, as you will need a mic cable in real world recording- usually at least 25-30ft. long. (This reminds me of speed records set by "bicycles" which are ridden 3 ft. behind a giant aerodynamic shield mounted to a muscle car- not exactly realistic!)

However, you could use the sound of the cable-less connection as a benchmark: judging the "best" microphone cable as the one with the least amount of deviation from that sound.

[Andy Simpson]

While I agree that this 'test' is extreme, it isn't unrealistic.

Yes, this can be used as a benchmark for cables.

For myself, I can't justify using mic cables again unless I absolutely have to. I have worked very hard to get resolution in my microphones and am happy to find such a large degree more than I expected. Maybe >5dB, if I had to quantify. Highly significant.

Perhaps with some mic designs this is not a feasible thing to do, for physical or even acoustic reasons, but for me I have tasted something much better and will absolutely be working this way at my next session (as long as I can contrive some sturdy stands!).

Andy

P.S.: in any case, since the thread has so far consisted largely of subjective opinions & debate, I would suggest that at least this test will give a repeatable and healthy result which nobody will find to be subjective.

[Tomas Danko]

Andy Simpson wrote on Mon, 16 July 2007 09:43

Klaus Heyne wrote on Mon, 16 July 2007 06:19 I recall, this "test" has come up in past threads and articles on mic cables. Only problem: The test is not realistic, as you will need a mic cable in real world recording- usually at least 25-30ft. long. (This reminds me of speed records set by "bicycles" which are ridden 3 ft. behind a giant aerodynamic shield mounted to a muscle car- not exactly realistic!) However, you could use the sound of the cable-less connection as a benchmark: judging the "best" microphone cable as the one with the least amount of deviation from that sound. While I agree that this 'test' is extreme, it isn't unrealistic. Yes, this can be used as a benchmark for cables. For myself, I can't justify using mic cables again unless I absolutely have to. I have worked very hard to get resolution in my microphones and am happy to find such a large degree more than I expected. Maybe >5dB, if I had to quantify. Highly significant. Perhaps with some mic designs this is not a feasible thing to do, for physical or even acoustic reasons, but for me I have tasted something much better and will absolutely be working this way at my next session (as long as I can contrive some sturdy stands!). Andy PS, in any case, since the thread has so far consisted largely of subjective opinions & debate, I would suggest that at least this test will give a repeatable and healthy result which nobody will find to be subjective.

I'd be interested in comparing the two recorded tracks by phase cancellation. Hopefully it would be quite enlighting.

[Klaus Heyne]

Andy Simpson wrote on Mon, 16 July 2007 09:43

I have worked very hard to get resolution in my microphones and am happy to find such a large degree more than I expected (by removing the cable and plugging the mic directly into the mic pre) Maybe >5dB, if I had to quantify. Highly significant.

It's news to me that the term 'resolution' is quantifiable and can be attached to dB units. Please give a definition for 'resolution', and how you define a 5dB improvement.

Quote:

...since the thread has so far consisted largely of subjective opinions & debate, I would suggest that at least this test will give a repeatable and healthy result which nobody will find to be subjective. I'd be interested in comparing the two recorded tracks by phase cancellation. Hopefully it would be quite enlighting.

As soon as you can define for us objective parameters of 'resolution', I will follow along.



In the meantime: Phase reversing (and thus pointing out any divergence between the cable and non-cable connections) still will need subjective interpreting in terms of musical meaning of these deviations- rather than assuming that the larger the deviation, the more useless the cable, you would need to decree what amount of deviation in what frequency band is least/most objectionable to the ear!

Quote:

There was also a gain of ~3dB for going without cable, so noise floor also gained

In audio measurements, noise floor improvement and gain increase are not necessarily directly linked. Your cable-less connection may have seen a slight gain increase (though I very much doubt that it was anything more than maybe 0.5 dB), but any noise floor improvement would need to be separately measured.

[ioaudio]

[Andy Simpson]

Klaus Heyne wrote on Mon, 16 July 2007 18:50

It's news to me that the term 'resolution' is quantifiable and can be attached to dB units. Please give a definition for 'resolution', and how you define a 5dB improvement. As soon as you can define for us objective parameters of 'resolution', I will follow along.

The definition of gain in resolution which I use is this:

the equivalent increase in perceived detail level from the equivalent gain in volume.

For example, by turning up the monitors by 5db I have a perception of increased detail.

This perception of increased detail for a 5dB monitor gain increment is roughly the same as I experienced in the test.

Subjective it is but I would guess that if we were all tested and asked to guage (in dB) increase of detail against increase in monitor gain, we would likely have similar results. So perhaps we can agree on some pseudo measurement which we will all be able to relate to in some useful way?

Quote:

In the meantime: Phase reversing (and thus pointing out any divergence between the cable and non-cable connections) still will need subjective interpreting in terms of musical meaning of these deviations- rather than assuming that the larger the deviation, the more useless the cable, you would need to decree what amount of deviation in what frequency band is least/most objectionable to the ear!

Alas, if we could make such measurements in a controlled way we could at least measure differences, which would render the subjective aspects as academic.

In any case, I would not expect to gain anything from phase cancelling as it would be impossible to get an actual cancellation. Impulse response tests would be more benefitial perhaps, but like I said, for anyone who can trust their ears, it is not a hard test.

Quote:

In audio measurements, noise floor improvement and gain increase are not necessarily directly linked. Your cable-less connection may have seen a slight gain increase (though I very much doubt that it was anything more than maybe 0.5 dB), but any noise floor improvement would need to be separately measured.

Well, the noise floor issue comes easily as matching the channels audibly reduced the noise-floor. I was listening at varying levels up to very loud to check this.
Regarding the gain issue, my results were repeated many many times without alteration. A significant increase in gain but far more significant, a bigger gain in resolution.

Andy