[00940]

Quote:

Originally Posted by jcx /img/forum/go_quote.gif – so you’d need to get the world to accept a new standard for compact 4 pin connector and to start recabling IEMs

To play the devil's advocate... TRRS plugs and jacks

edit: Steve was faster on this.

 

[jcx]

I think I've mentioned before that sensitive IEMs could be "unamped" with step-down transformers to reduce hiss - and possibly extend low frequency corner

how about a passive "balanced" output box for portable players? - still going to be hard to match a Nano's case size

its hard to get genuinely low contact reisitance with the trs style connector - pretty much limited to "point contact" cantelever beams which have to ride over the notch in the tip

much lower R multi-contact pin/socket geometries are readily available

not that the 10's of miliOhms of even poor TRS contacts are likely audible - as long as they are completley stable

 

[Steve Eddy]

Quote:

Originally Posted by jcx /img/forum/go_quote.gif I think I've mentioned before that sensitive IEMs could be "unamped" with step-down transformers to reduce hiss - and possibly extend low frequency corner

Then you could use something like the PC600/150 which is a 2:1 stepdown.

Quote:

how about a passive "balanced" output box for portable players? - still going to be hard to match a Nano's case size

You mean "passive" as in transformers? Or do you have something else in mind?

Quote:

its hard to get genuinely low contact reisitance with the trs style connector - pretty much limited to "point contact" cantelever beams which have to ride over the notch in the tip much lower contact R pin/socket contacts are readily available

True.

k

 

[moonboy403]

Here were some measurable differences of a balanced and SE HD600 posted by a member a while ago.

Here are some relevant info regarding the test:

"We have measured the differences in frequency response, impulse response, distortion and energy storage on the HD600 single ended, compared to balanced (using a RPX-100 balanced amp) using a single ended signal, and the differences were measurable despite the signal not being balanced."

"Yes, that's right, we just changed the HD600's stock single-end cable for a balanced one from Rudistor. We used the same amp's input fed with a single-end signal from the Apogee interface plugged into the Mac computer, and just re-calibrated the system prior to each measurement."

"The dummy ear has a round area to make you placing the headphone with its center pointing to the dummy ear canal. Moreover we repeated measurements and had consistent results."

 

[JaZZ]

Quote:

Originally Posted by Shike /img/forum/go_quote.gif Two issues: 1) I fail to see how that's even relevant.

Quote:

Originally Posted by xnor /img/forum/go_quote.gif JaZZ, what's the point in throwing random off-topic quotes into a discussion like this? To make fun out of other people?

Yes, I thought badmouthing other people would be fun.

Quote:

Your reputation is suffering badly...

Oh yes, my reputation...

Quote:

Btw, I've heard an effect in direct comparison – in favor of unbalanced... funny, isn't it?

Yes, funny. After all it made a difference. But I don't really care. Did you do proper level matching? Did you do it by ear or by measurement?

.

 

[xnor]

Haha that's very funny. Not.

 

[Currawong]

Quote:

Originally Posted by xnor /img/forum/go_quote.gif JaZZ, what's the point in throwing random off-topic quotes into a discussion like this?

It's a very relevant quote. It's important to understand that some people are only out to validate their beliefs, not learn the truth about things. The more they are confronted with the possibility that their beliefs might not be true, the more obsessed they become with finding evidence that they are. I've even heard of a person at a meet, when asked to try a different cable on his headphones, shouted at the person about DBT.

Quote:

Btw, I've heard an effect in direct comparison – in favor of unbalanced... funny isn't it.

With what amp and headphones? Some people have said with some gear they preferred the results single-ended with a pair of headphones than balanced.

 

[Steve Eddy]

Quote:

Originally Posted by moonboy403 /img/forum/go_quote.gif Here were some measurable differences of a balanced and SE HD600 posted by a member a while ago.

Thanks.

Though it brings up more questions than answered.

For example, are the graphs the result of averaging, or were they all taken from one-shot measurements?

Were output levels matched between balanced and single ended?

Where the output impedances matched between balanced and single ended?

k

 

[Shike]

Quote:

Originally Posted by Currawong /img/forum/go_quote.gif It's a very relevant quote.

To the topic? No. I'm pretty sure this is about balanced and unbalanced . . . not electrostatics and their cult following. I'll gladly dissect your post since you want to make this part of the topic though.

Quote:

It's important to understand that some people are only out to validate their beliefs, not learn the truth about things.

Really? This is a funny concept . . . because seeking the truth either means to validate ones belief OR to have it disproved. Head-fi isn't a particularly scientific oriented forum. Scientific discussion is actually not allowed in certain sections. What's wrong with seeking the "truth" in a forum dedicated to science? When one seeks knowledge should the first place they go be a university or a church?

Quote:

The more they are confronted with the possibility that their beliefs might not be true, the more obsessed they become with finding evidence that they are.

Pot meet kettle.

Quote:

I've even heard of a person at a meet, when asked to try a different cable on his headphones, shouted at the person about DBT.

How much time do you waste on bible thumpers? Same thing. I've never been to a meet, but I can completely understand the sentiments.

 

[moonboy403]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif Thanks. Though it brings up more questions than answered. For example, are the graphs the result of averaging, or were they all taken from one-shot measurements? Were output levels matched between balanced and single ended? Where the output impedances matched between balanced and single ended? k

Seeing that the person and his sound engineering friends conducted the test looking for measurable differences between balance and SE, I assumed that levels were matched for all trails. Moreover, judging from the context of "Moreover we repeated measurements and had consistent results", I also assumed that the results were not averaged.

As for impedance matching, I also assumed that it wasn't matched.

You can always PM that head-fier and ask.

 

[b0dhi]

Matching the output impedances would be contrary to the purpose of the measurement. We are trying to determine real-world performance.

 

[Steve Eddy]

Quote:

Originally Posted by moonboy403 /img/forum/go_quote.gif Seeing that the person and his sound engineering friends conducted the test looking for measurable differences between balance and SE, I assumed that levels were matched for all trails. Moreover, judging from the context of "Moreover we repeated measurements and had consistent results", I also assumed that the results were not averaged. As for impedance matching, I also assumed that it wasn't matched.

If the goal was to look for measureable differences between balanced and single ended, then that's the only thing that should have been tested for. In other words, the ONLY difference should have been that of balanced versus single ended keeping all else equal.

And averaging should have been done. You can make several one-shot measurements and get several slightly different results. So what you do is average a number of measurements to factor out the variability. Otherwise, all you may end up measuring is the measurement variability.

Quote:

You can always PM that head-fier and ask.

I may do that. Thanks.

k

 

[Steve Eddy]

Quote:

Originally Posted by b0dhi /img/forum/go_quote.gif Matching the output impedances would be contrary to the purpose of the measurement. We are trying to determine real-world performance.

I thought what was trying to be determined was balanced versus single ended, all else being equal.

Edit: I just checked the original poster in that thread emphasized keeping all else equal. And as I said previously, all else being equal, a headphone doesn't know balanced from a hole in the ground and there would be no earthly reason for any change in the headphone's performance driven one way or the other, again, all else being equal.

k

 

[b0dhi]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif Edit: I just checked the original poster in that thread emphasized keeping all else equal. And as I said previously, all else being equal, a headphone doesn't know balanced from a hole in the ground and there would be no earthly reason for any change in the headphone's performance driven one way or the other, again, all else being equal.

All else was equal. The same amplifier was used for the two measurements, with the same headphone unit, cables, calibrated, etc.

As for your claim about balance drive not having any theoretical benefit, that's not the impression I got from amp designers such as AMB Labs, but I'm sure someone more qualified can respond to that.

 

[Steve Eddy]

Quote:

Originally Posted by b0dhi /img/forum/go_quote.gif All else was equal. The same amplifier was used for the two measurements, with the same headphone unit, cables, calibrated, etc.

You can't quite say it was the same amplifier. It may have all been in the same box, but what was feeding the headphones in balanced mode wasn't exactly what was feeding it in single ended mode.

The amp in question ultimately has four separate amplifiers in it. In the test, it was being fed a single ended signal from the source. In this instance, the unbalanced output uses just two of those four amplifiers just as you'd have with any single ended amplifier.

The balanced output then uses a phase splitter to derive an inverted signal to feed the other amplifier and then the outputs of those two amplifiers are bridged, creating the "balanced" output.

So at the very least, you'll end up with two different output impedances between balanced and single ended.

The output impedance is spec'd at "3 Ohms to 1200" though I don't see any provision for changing the output impedance of that amp unless it's something that can be adjusted internally.

Quote:

As for your claim about balance drive not having any theoretical benefit, that's not the impression I got from amp designers such as AMB Labs, but I'm sure someone more qualified can respond to that.

And I'd love to hear from them.

Because as far as I can see, the only thing the headphone knows is the voltage being applied across its terminals and the output impedance of whatever's driving it. And provided both of those parameters are the same, I don't see how any change can come about in the behavior of the headphone in question.

k