Behringer X32 has a air leak in the mains!

Re: Behringer X32 has a air leak in the mains!

Mark Wilkinson said:
Thanks guys,

Checked the talkback, not that.

Maybe I'm making a mistake, and there is no validity in the Main Out voltage readings.
On either 7 or 8 main outs (Compact), when the desk is first powered up, XLR pins 2 & 3 read 0.13mV (-78dbV). When I raise Main fader to 0, voltage goes to just below 3mV (-50dbV)
Once the Main fader has been raised to 0, the voltage stays at 3mV no matter where the fader is.....even all the way down.
Either turning the desk off, or changing the sampling frequency in setup, returns voltage to 0.13mV (when the Main fader is all the way down)

More baffling:
1. the speaker hiss stays the same, whether first powered up at 0.13mV or at 3mV, as described above with main fader down.
2. the hiss increases plenty when raising the Main fader to 0, even while the voltage stays at 3mV no matter where the fader is....

maybe i'm clueless on how to read, or what to make of, balanced voltages.


Things i do know though:
XLR's unplugged at mixer = no hiss. Speakers plugged into my old analog mixer = no hiss.

Thanks for direction, mark
Click to expand...

My experience is that there is noticeable hiss in the Meyer UPJ-1P's that I use for my shop monitors when connected to any X32, and that the hiss stays the same regardless of the master fader position. That was alarming until I then connected my previous best small analog console, the APB Dynasonics House Rack. The hiss was the same or somewhat less (it's a long time ago that we did this) on the APB with the master fader off, but went up very drastically when the fader was in its usual 0 db position. We never heard the APB through a PA when used in a real situation, and we never worried again about the X32 hiss at idle.

My guess for your situation is that you have an effect return or something else that is up when you don't think it's up, or that you have a bad console. There was a documented and notable whine coming out of the outputs at some settings on some consoles, and Behringer seemed to find and fix it eventually. If you search the X32 megathread for "console whine" or something like that I and others wrote a lot about it a little more than 2 years ago. It was different depending on if you were running at 44 or 48k.

I don't know anything about how you are measuring the noise floor or what it means. The numbers you are giving seem high compared to what I think I'm hearing, and I know that comment could cause discussion (to put it politely).

The Meyer speakers are irritating in that you cannot turn down the gain going to them without inserting another device, whether it's the pad that you are using or something else. They do have other significant virtues, though.

Those MTS4's are now legacy products, along with my beloved MSL-4. Do you like them a lot?

Is that pad solving the problem for you, or are you hurting for gain?

Good luck getting to the root of this!
 
Re: Behringer X32 has a air leak in the mains!

Dan Mortensen said:
My experience is that there is noticeable hiss in the Meyer UPJ-1P's that I use for my shop monitors when connected to any X32, and that the hiss stays the same regardless of the master fader position. That was alarming until I then connected my previous best small analog console, the APB Dynasonics House Rack. The hiss was the same or somewhat less (it's a long time ago that we did this) on the APB with the master fader off, but went up very drastically when the fader was in its usual 0 db position. We never heard the APB through a PA when used in a real situation, and we never worried again about the X32 hiss at idle.

My guess for your situation is that you have an effect return or something else that is up when you don't think it's up, or that you have a bad console. There was a documented and notable whine coming out of the outputs at some settings on some consoles, and Behringer seemed to find and fix it eventually. If you search the X32 megathread for "console whine" or something like that I and others wrote a lot about it a little more than 2 years ago. It was different depending on if you were running at 44 or 48k.

I don't know anything about how you are measuring the noise floor or what it means. The numbers you are giving seem high compared to what I think I'm hearing, and I know that comment could cause discussion (to put it politely).

The Meyer speakers are irritating in that you cannot turn down the gain going to them without inserting another device, whether it's the pad that you are using or something else. They do have other significant virtues, though.

Those MTS4's are now legacy products, along with my beloved MSL-4. Do you like them a lot?

Is that pad solving the problem for you, or are you hurting for gain?

Good luck getting to the root of this!
Click to expand...


Many Thanks Dan,

The Main Out voltage reading, although repeatable without fail per previous post, doesn't seem to tie to the hiss in any way...so I've ignored the voltage reading other than making note its frequency bounces around between 120-160 khz....

A factory reset has reduced the hiss some. I have no idea why, as I'm pretty sure all inputs and FX were muted or unassigned.
Like you, I compared the hiss more carefully to my quietest analog mixer, a high spec A&H x-one 464 dj mixer. And found the A&H had a little more hiss than I remembered....maybe more on par with the x32 than not, after the factory reset.
So bottom line, I'm living happily with the hiss....padding it within the quietness of my house and lower listening levels,.... and then removing the pad, and not even noticing the hiss at full levels..

Yes, I like the mts4a's a lot...other than the huge difficulty in moving them around. I guess that's just the price of having it all in one box.
In fact, I love the damn things.... even if I can't move them around. They are so coherent sounding they make me laugh sometimes.....and show me the virtue of a fully engineered solution that extends down to sub bass.
They also show me how much i have yet to learn about speaker alignment!!

I imagine the MSL-4's sound very similar? What bottom end do use with them?
 
Re: Behringer X32 has a air leak in the mains!

Mark Wilkinson said:
Many Thanks Dan,

The Main Out voltage reading, although repeatable without fail per previous post, doesn't seem to tie to the hiss in any way...so I've ignored the voltage reading other than making note its frequency bounces around between 120-160 khz....
Click to expand...

What's this, now? Over 100kHz? Pretty sure that's inaudible.

When I was measuring the whine it was around 4kHz, IIRC which I'm sure I don't, and it was audible clearly. 120-160k would not be hiss but rather nothing to our ears.

Mark Wilkinson said:
A factory reset has reduced the hiss some. I have no idea why, as I'm pretty sure all inputs and FX were muted or unassigned.
Like you, I compared the hiss more carefully to my quietest analog mixer, a high spec A&H x-one 464 dj mixer. And found the A&H had a little more hiss than I remembered....maybe more on par with the x32 than not, after the factory reset.
So bottom line, I'm living happily with the hiss....padding it within the quietness of my house and lower listening levels,.... and then removing the pad, and not even noticing the hiss at full levels..
Click to expand...

That's happy news, and I hope it continues.

Mark Wilkinson said:
Yes, I like the mts4a's a lot...other than the huge difficulty in moving them around. I guess that's just the price of having it all in one box.
In fact, I love the damn things.... even if I can't move them around. They are so coherent sounding they make me laugh sometimes.....and show me the virtue of a fully engineered solution that extends down to sub bass.
They also show me how much i have yet to learn about speaker alignment!!

I imagine the MSL-4's sound very similar? What bottom end do use with them?
Click to expand...

Agreed on huge difficulty to move them around; aren't they over 400# each?

Yes, I assume the MSL's sound similar, since Meyer has a remarkable ability (and goal) to have all the products, large and small, have as identical a voicing as possible given the limitations of physics. I've never heard the MTS's.

I have both Bag End ELF subs and Meyer USW-1P's, although I have some MSL's in a ballroom dance club and they had me take the Bag Ends out because the MSL's had plenty of low end for both their application/needs and their very live room. The MSL's make a fairly horrible sounding room sound OK.

Back to your issue, the Monitor output XLR's had that whine way worse than the Mix Bus outputs, and the monitor volume pot is actually an attenuator so that unity gain between the Mix Bus Outputs and Monitor outputs is full output rotation on that attenuator; did that have anything to do with your problem, maybe? You would have had to be connected to those Monitor outs rather than the Mix Bus outs for this to be true, though.
 
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Re: Behringer X32 has a air leak in the mains!

Thx Dan,

Yes, I'm guessing the high freq reading is why the 3 mV voltage doesn't mean anything noise wise.

Just 280 lbs.... but they are such deep trap boxes, the castor wheels end up being only 10 inches apart and feel tippy

I just tried feeding the mts with the monitor outs...... complete dead silence fully attenuated ...hey, I found my built in hiss pad :lol:
At unity gain, fully CW, monitor hiss is same as main outs....so AOK.
 
Re: Behringer X32 has a air leak in the mains!

Mark Wilkinson said:
Thx Dan,

Yes, I'm guessing the high freq reading is why the 3 mV voltage doesn't mean anything noise wise.

Just 280 lbs.... but they are such deep trap boxes, the castor wheels end up being only 10 inches apart and feel tippy

I just tried feeding the mts with the monitor outs...... complete dead silence fully attenuated ...hey, I found my built in hiss pad :lol:
At unity gain, fully CW, monitor hiss is same as main outs....so AOK.
Click to expand...

That is really fascinating!

What is your console build date? (Located on back near power cord somewhere.) Behringer must have completely fixed that problem by relocating the wires.

No whine on the headphone outs either?

If that is all true, then you have indeed found your hiss reducer.

On all my consoles, which were built 11/2012, if we use them as monitor consoles we have to route the solo out to a Mix Bus XLR because the Monitor outs are unbearable. Since that completely solves the whine problem I have not tried further to resolve the root whine problem.

Glad that works for you!
 
Re: Behringer X32 has a air leak in the mains!

Dan Mortensen said:
That is really fascinating!

What is your console build date? (Located on back near power cord somewhere.) Behringer must have completely fixed that problem by relocating the wires.

No whine on the headphone outs either?

If that is all true, then you have indeed found your hiss reducer.

On all my consoles, which were built 11/2012, if we use them as monitor consoles we have to route the solo out to a Mix Bus XLR because the Monitor outs are unbearable. Since that completely solves the whine problem I have not tried further to resolve the root whine problem.

Glad that works for you!
Click to expand...


Thx Dan!
Build code is 06/13.
Just checked the headphones...totally quiet.

My Compact only has a pair of TRS bal/unbal monitor outs.
Does your 2012 full x-32 do the same thing on both xlr and trs outs?
 
Re: Behringer X32 has a air leak in the mains!

Guys, thanks for all your help. Can't remember who, but someone said I may have a metric crap load of gain. So I went up to look at the amps. Before the amps I found this box labeled controller. On the input side I found a switch that read what I beloved to say -10 or +4. It was switched to -10. I put it to the +4 position and the hiss left, but I lost about 25% of my volume. I still had plenty of room on the board so I was able to get the volume back and the hiss stayed away. Problem is I don't what the switch is, or what I actually did. Any thoughts?

IMG_20150301_101912517.jpg
 
Re: Behringer X32 has a air leak in the mains!

Jason Johnston said:
Guys, thanks for all your help. Can't remember who, but someone said I may have a metric crap load of gain. So I went up to look at the amps. Before the amps I found this box labeled controller. On the input side I found a switch that read what I beloved to say -10 or +4. It was switched to -10. I put it to the +4 position and the hiss left, but I lost about 25% of my volume. I still had plenty of room on the board so I was able to get the volume back and the hiss stayed away. Problem is I don't what the switch is, or what I actually did. Any thoughts?

View attachment 12085
Click to expand...

Yes it stands for +4dBu (1.223V) or -10dBV ( .316V) 0VU reference. So the +4 position has about 12 dB less voltage gain.

If the +4 position sounds better use it... problem solved.

JR
 
Re: Behringer X32 has a air leak in the mains!

Robert Lofgren said:
home consumer products like you CD player have output levels in the -10dBV region while professional audio gear uses +4dBu.

So this amp can take both of these types depending on the switch position.
Click to expand...

While most home hifi products are closer to -10dBV than +4dBu, they are not actually nominal -10dBV= 0VU, if anything more like 500mV=0VU. The -10dBV standard is left over from the small format (narrow track) open reel tape machines very popular in the 1980s for bedroom/project recording set ups. The lower voltage nominal 0VU supported 20dB of signal headroom while using cheaper lower voltage power rails. Another subtle benefit of the -10dBV standard was that the slow (0.5v/uSec) op amps common back then were fast enough to reproduce audio within those lower voltage rails. -10dBV was always considered the amateur or pro-sumer standard, while +4dBu was the big boy professional reference standard.

JR

PS I wrote a column on the subject back in the '80s comparing performance of both and +4 had a very slight noise floor advantage over -10dBV, but the performance differences between them were mostly inconsequential.
 
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