PLEASE, PLEASE, PLEASE Give my subwoofer Balanced XLR connections

[markw]

Anything is possible, but

It *could* be a non-issue, but panther did say that he was in a high-interference environment. If, for the sake of argument, we say that the rest of his (unbalanced) interconnects are 1 meter and the run to his sub is going to be 10 meters (not unreasonable if he runs the cable around the perimeter of the room), then he's got 10x the potential antenna in his cabling. It's possible that he doesn't even have analog audio interconnects at all, so he wouldn't have any audible interference already apparent in the system.

When I was in college in Boston's Back Bay area, I could pick up WBCN on my Sony MDR-V6 headphones as clear as day, and without the added expense of any kind of radio tuner. A headphone cable's signal level is much closer to line than mic. It's not a stretch that panther and others could face similar challenges. Only they can make that decision. In no (properly wired) case will an unbalanced connection pick up less noise than a balanced one, but whether or not the listener can hear the difference...

..he won't know until he tries, will he?

For what it's worth, I've been doing semi pro sound for a couple of years myself.

Severe RFI is a reality but the situation you are describing is an exception. Besides, the headphone cables were not shielded and the drivers themselves could be the culprit as well, not to mention a solder junction. And, if it is that severe, I'm pretty sure it would have shown itself before this.

Again, all this agonizing over a problem that probably doesn't even exist is a waste of time, worry and bandwidth. A lot of good information has come out of this thread and it's time he did a little experimentationtation for himself instead of crying over something that, in all probability, is a non issue.

Point blank, he could "borrow" a shielded cable with RCA's from RatShack or a similar entity of a similar length to see if there IS a problem but since he's reluctant to even try that, well then..., why should I even bother. I'm outta here until he tries something for himself.

And, if this is part of a crusade to get balanced XLR connectors on all audio equipment, why not get Neutiik Speakons as a standard speaker connector?

 

[Francious70]

http://www.bcae1.com/ballndrv.htm

Paul

 

[b_panther_g]

“Point blank, he could "borrow" a shielded cable with RCA's from RatShack or a similar entity of a similar length to see if there IS a problem but since he's reluctant to even try that, well then...,”

I never stated that I was reluctant to try anything. Actually I have tried what you described. The result…

There was an audible difference in the sound. (No I don’t have the measured results)

I’m a computer guy and I have an HTPC. I also have a friend with a home studio. So I borrowed his sound card (E-MU 1820M) and an extra pro amp. I played music from the balanced output (the PC and sound card are located in the front of the room) to the AMP (located in the rear of the room, where I want the sub) connected to a B&W 303 speaker. I also repeated the same thing with an unbalanced connection and a RCA to XLR connector located at the amp. (I know this was a very dirty setup, but hey, it’s what I had) The result…

The balanced connection was cleaner every time. I even blind folded my girl friend and had her listen. She picked the balanced connection like 18 out of 20 times.

I have tried to run an unbalanced connection. It doesn’t sound as clean as I’d like it to. I concluded that the balanced connection was cleaner than the unbalanced.

I have a powered sub. So I was wondering why there weren’t more balanced connections for subs.

Bottom line. Don’t assume that because I didn’t want to detail my unscientific experiment that I haven’t done anything.

Later,
B

 

[b_panther_g]

Francious70,

Thanks for the web page. It looks like a good read.

It’s funny, just when I think I know something, it turns out that there’s so much more to learn.

Thanks again.

Later,
B

 

[djoxygen]

http://www.bcae1.com/ballndrv.htm

Interesting, thanks for the link!

They are doing exactly what I had speculated/feared - using the shield as the negative. I'd sure be curious to hear how effective it is. The theory makes me really nervous because it trumps the very purpose of the shield. To utilize common mode rejection, the interference has to hit both conductors equally. In a co-ax cable, the shield is designed to pick up more interference than the central conductor. It may be better in this semi-balanced scheme to use zip cord, speaker cable, or other non-co-ax cable for the run so that neither conductor is shielded.

Any electrical engineers out there want to weigh in on this?

 

[djoxygen]

I have tried to run an unbalanced connection. It doesn’t sound as clean as I’d like it to. I concluded that the balanced connection was cleaner than the unbalanced.

I have a powered sub. So I was wondering why there weren’t more balanced connections for subs.

Bottom line. Don’t assume that because I didn’t want to detail my unscientific experiment that I haven’t done anything.

You definitely did your homework. If you don't want to spring the major $$ for a balanced pre/pro, you should make the shortest possible RCA connection to a transformer like the Aphex I mentioned, and then run the XLR to your sub. It may not be the best possible solution, but <$200 is a lot less painful than >$3K.

 

[b_panther_g]

“You definitely did your homework. If you don't want to spring the major $$ for a balanced pre/pro, you should make the shortest possible RCA connection to a transformer like the Aphex I mentioned, and then run the XLR to your sub. It may not be the best possible solution, but <$200 is a lot less painful than >$3K.”

djoxygen,


Thanks for the suggestion. You’re right; it is a lot less painful.

I really don’t know what I’m going to do. I have some ideas about other tweaks that may ultimately be more rewarding. Who knows what’ll happen. But hey, for me anyway, it’s all part of the fun.

Later,
B

 

[djoxygen]

Severe RFI is a reality but the situation you are describing is an exception. Besides, the headphone cables were not shielded and the drivers themselves could be the culprit as well, not to mention a solder junction. And, if it is that severe, I'm pretty sure it would have shown itself before this.

Now we know that panther's situation does warrant it. In my case, the exact same set of pro gear and headphones was dead silent in my Minneapolis home during summer break, so it was definitely site specific, and yes, an exceptional situation.

And, if this is part of a crusade to get balanced XLR connectors on all audio equipment, why not get Neutiik Speakons as a standard speaker connector?

That would put a lot of snake-oil salesman in the line at the soup kitchen, wouldn't it ?!?!? >:-D

If I weren't using active monitors with balanced connections, I'd be more than irked that I'd have to use plain old speaker cables. Not to mention the need to use 2 sets of cables for each speaker in a bi-amped system. Yep, Speakons would be the ticket, and the cabling wouldn't really be much bigger than 2 pairs of 14AWG. (No worries about polarity either!)

(Rant) Given the prices that some of us pay for our consumer HT gear, there's no excuse except our own acquiescence for the prevalence of RCA jacks on even the most esoteric pieces. On the back of a $4K pre/pro there should be complete sets of properly wired/impedanced/amplified BNCs and XLRs available for at least 2 inputs and 1 output. Any manufacturer who says cost is a factor is relying on the fact that even the most educated HT consumers may not be aware that Alesis makes signal processors with 4 balanced jacks that sell for under $200. I'll be Joan of Arc if there's people I can lead on this crusade. (/Rant)

 

[markw]

Well ,you definitely fall in the minority then.

I have tried to run an unbalanced connection. It doesn’t sound as clean as I’d like it to. I concluded that the balanced connection was cleaner than the unbalanced.

I'm curiuous about what "clean" means but that's another issue entirely.

It would seem that you need to search out that gear that offers balanced outputs. It may cost more but you gotta do what you gotta do.

I'm a big guy and would just looove a sporty little miata but, realities force me to buy a different vehicle that cost more, burns more gas and lacks the sportiness of that little sucka. But hey, that's my cross to bear, nobody elses.

I have a powered sub. So I was wondering why there weren’t more balanced connections for subs.

Most people simply don't need them. Simple as that. Manufacturers are selling these things hand over fist just as they are. Balanced connectors don't seem to be a major need for most subwoofer users. They work fine with the old fashioned unbalanced connectors. Why should all buyers have to pay for what they don't want or need just because you need them?

Just like my car, I should wonder why all cars won't fit my frame? That would be foolish and selfish, no? I'm sure they could be made but it would cost everyone more. Why should they have to pay for me?

Now, there ARE subs out there that have balanced connectors but, just like my car, you might have to pay more for what you need. Wotta country...

 

[djoxygen]

Most people simply don't need them. Simple as that. Manufacturers are selling these things hand over fist just as they are. Balanced connectors don't seem to be a major need for most subwoofer users. They work fine with the old fashioned unbalanced connectors. Why should all buyers have to pay for what they don't want or need just because you need them?

By the same token, I still have to pay for the sea of empty RCA jacks on the back panel. And really, who among us even *needs* a HT system at all?

I think there should be a range of options available to everyone depending on their needs/desires/ear sensitivity. As for myself, I have limited my pre/pro prospects to those that have 7.1 XLR outs on the back. As you suggest, I have always planned to do what I gotta do. I'm thrilled to see that there are at least triple the options as when I started to research and assemble my HT system a couple years ago. I do firmly believe that some high-end manufacturers should be hung out to dry for even trying to sell stuff at their MSRPs that has NO options besides RCA for transporting analog audio.

 

[b_panther_g]

The reason for wondering was because, for long cable runs, balanced connections generally provide a cleaner signal than unbalanced connections. This is especially useful for subs. I suspect that if more people heard/knew the difference they would use them more.

That’s why I put the question out there, to get feedback. I wanted to know how many other people thought the same thing.

Besides, I already pay for stuff I don’t need (DTS NEO, Circle Surround). How much could 1 balanced output cost? But hey, I guess not everyone’s ready for a balanced HT world.

Later,
B

 

[mtrycrafts]

The reason for wondering was because, for long cable runs, balanced connections generally provide a cleaner signal than unbalanced connections. This is especially useful for subs. I suspect that if more people heard/knew the difference they would use them more.

Later,
B

But, hearing wise, human hearing is poor at the low frequency band compared to mid band. You just don't notice small differences. The Just noticable Differences is huge compared to midband:

http://www.pcavtech.com/abx/abx_crit.htm

 

[b_panther_g]

Mtrycrafts,


If you are suggesting that my experiment does not prove that the balanced connection is the reason I heard differences in the subwoofer, you are 100% correct.

Human hearing is considerably more sensitive to mid and high frequencies. And most of what I heard during my experiment was mids and highs.

There could be tons of reasons why I heard a difference in the sub. I also admit that 1 of them could be psychological. I try to be as objective as possible, but I’m still human.

The only way to prove what I heard is with a carefully controlled BDT. I don’t have the facilities to perform one, so I’m left with questionable unscientific experiments.

That’s a BIG reason why I didn’t want to post my experiment. I didn’t want everyone to begin focusing on the experiment and not the question. I’ve seen it happen on too many forums. A huge argument erupts and everyone is picking apart every aspect of another persons experiment or experience and no one focuses on the question.

I was trying to ask a very general question. Does anyone else think that it’s a good idea to have balanced connections become standard for subwoofers? The reason(s) why I came up with the question are kind of irrelevant.

Oh well, hopefully more people will get involved and answer the question.

Later,
B

 

[djoxygen]

But, hearing wise, human hearing is poor at the low frequency band compared to mid band. You just don't notice small differences

True indeed, but depending on one's configuration (and panther has already told us that this was the case) that part of the audio spectrum isn't the problem.

If, as an example, one was using the crossover in one's receiver/pre-pro to set the crossover frequency/slope for the .1 channel, one might defeat the crossover on the sub so as not to conflict. Running a long unbalanced cable to the sub could possibly pick up environmental interference at higher frequencies that the crossover had previously filtered out. This would introduce unwanted noise in ranges where not only is the human ear quite sensitive, but also that the sub shouldn't be trying to reproduce.

 

[djoxygen]

Does anyone else think that it’s a good idea to have balanced connections become standard for subwoofers?

I believe balanced connections should be an available option for all audio interconnects, and they pretty much are, for the right price. Not necessarily mandated or "standard" (whatever that means). There is no (reasonable) question that balanced connections are better than unbalanced ones. It is up to the listener to determine if the difference in quality is worth the difference in price.

Someday, balanced audio will be regarded much as component video is now. If you're serious you won't mess around with anything less.

 

[moverton]

djoxygen wrote:
"I could pick up WBCN on my Sony MDR-V6 headphones as clear as day"

I cannot see how this was being introduced through the wiring to the headphones. It must have been bleeding across in the receiver into the amplification stage for the microphone. And it seems like it must have been coming from the tuner. The raw radio signal would not be audible of course as it is in the megahertz range.

not sure but doesn't seem to make sense.

 

[djoxygen]

I cannot see how this was being introduced through the wiring to the headphones. It must have been bleeding across in the receiver into the amplification stage for the microphone. And it seems like it must have been coming from the tuner. The raw radio signal would not be audible of course as it is in the megahertz range.

I would love to accept your explanation. However, there was *no *tuner *in *the *system. No consumer audio gear at all, in fact. This was my project studio recording rig consisting entirely of a Tascam 238 8-track (not the kind that plays Doobie Brothers, the kind for doing multi-track recording), a Peavey XR-1200C mixer, a couple keyboards (Yamaha DX-100 and Sequential Six-Track), and Sony MDR-V6 headphones. The strength of the reception varied with the position and extension of the headphone cable. There were some orientations clean enough that I could work, and some that made my rig unusable.

I will admit that "clear as day" is a bit of hyperbole. If I moved to the right (or rather wrong) position, I could identify the song playing. Also, I didn't claim that the headphones themselves were demodulating the signal, just acting as an antenna for the system. I don't know for sure what piece of gear was demodulating, but I have at least one recording with a little extra Steely Dan identifiable at the beginning.

 

[markw]

Amazing...

... I didn't claim that the headphones themselves were demodulating the signal, just acting as an antenna for the system. I don't know for sure what piece of gear was demodulating, but I have at least one recording with a little extra Steely Dan identifiable at the beginning.

For the recording to have sound from the headphone wire antenna, that signal would have to have been fed back (at least) through the power amplifier (or whatever amp the phones were plugged into), through the output of the recorder, to it's input and finally to the tape heads.

 

[djoxygen]

For the recording to have sound from the headphone wire antenna, that signal would have to have been fed back (at least) through the power amplifier (or whatever amp the phones were plugged into), through the output of the recorder, to it's input and finally to the tape heads.

Yes. I know how the signal gets to the tape. They probably wouldn't have graduated me if I didn't. Who was demodulating the FM is still a mystery, and to be honest, I haven't given it a minute's thought in the last 14 years, nor am I much interested in figuring out now. I only brought it up as an example of how outside EM and RF interference can get into a system at audible levels. Balanced connections in that old rig may or may not have helped the problem. The interference was there way back then, and (especially in urban environments) isn't any less today. Balanced interconnects are one way to guard against the possibility.