You are here

Technical question regarding +4 vs -10 on moniotrs

For everything after the recording stage: hardware/software and how you use it.

Re: Technical question regarding +4 vs -10 on moniotrs

Postby Hugh Robjohns » Mon Aug 10, 2020 10:18 am

ef37a wrote:there can be no dispute surely that the 'cold' side of the balanced input is not getting signal?

True. But completely irrelevant...

Without digging out the formula I am not sure how that affects the output.

It doesn't.

A differential receiver looks for the voltage difference between its two inputs. So it makes no difference to the output level at all whether the signal is all on the hot side with nowt on the cold, of if both inputs receive half the signal each but in opposite polarities.

That's one of the beauties of the arrangement!
User avatar
Hugh Robjohns
Moderator
Posts: 28322
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Technical question regarding +4 vs -10 on moniotrs

Postby ef37a » Mon Aug 10, 2020 10:25 am

Hugh Robjohns wrote:
ef37a wrote:there can be no dispute surely that the 'cold' side of the balanced input is not getting signal?

True. But completely irrelevant...

Without digging out the formula I am not sure how that affects the output.

It doesn't.

A differential receiver looks for the voltage difference between its two inputs. So it makes no difference to the output level at all whether the signal is all on the hot side with nowt on the cold, of if both inputs receive half the signal each but in opposite polarities.

That's one of the beauties of the arrangement!

Yes, I half thought that half way through my post! Still, if it helps someone else's understanding I don't mind looking a bit of a twit.

I WAS right though about the puniness of many budget AI outputs! I cannot really see why? IF they have even modest internal rails it cost nothing to increase op amp gain. No wonder so many active monitors have too much gain and are therefore noisy.

Dave.
ef37a
Jedi Poster
Posts: 11998
Joined: Mon May 29, 2006 12:00 am
Location: northampton uk

Re: Technical question regarding +4 vs -10 on moniotrs

Postby Hugh Robjohns » Mon Aug 10, 2020 10:29 am

+10dBu should be plenty to get any modern active speaker rockin' the doors off. And it's only 4dB lower than the maximum output of the alternative interface which apparently does blow the doors off.

So, if we accept that the cabling is all fine there are only two possibilities as far as I can see:

1. A faulty UR22 -- possible but unlikely.

2. User error in configuration or operation -- which is by far the most likely scenario.

I've not used the UR22, but I'd be checking those front panel master volume controls and then all the software routing and mixer facilities.
User avatar
Hugh Robjohns
Moderator
Posts: 28322
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Technical question regarding +4 vs -10 on moniotrs

Postby CS70 » Mon Aug 10, 2020 10:40 am

Burdenko wrote:
CS70 wrote:Didn't ADAM monitors have a switch to change between the two levels? You are using it when moving from RCA to XLR, right?

Yep, exactly. There is a switch, I use it. In previouse post I wrote that with another sound card ti is super much louder - I am lissening now and really differecne in volume is not that drastic, and I even wouldn't have written about it here if it was only about volume, cause I can rise it on monitor (now it is on 0 and can be rised up to +18db).

Yeah that's why the gain controls are there - if a source has slightly lower output than a referenced one, you compensate with that.

But boosting it like that does not giving desired result - sound becomes muddy. So for now I tend to think that there is some problems with my UR22.

Ha, That would make me think that there's a problem with the monitors! :D
But of course it can be the UR22 as well.

Which musical material are you using for comparison?

It behaves like if it have only unballanced outputs - through unbalanced cable it sounds rather loud (if to compare with same levels but through balanced) and quality of sound is normal, and with M-audio through ballanced cables it sounds about 30% louder, but it percived even louder because of entire range of frequencies and especially low and high frequencies are better heard.

For a short cable length, so long the right inputs and outputs are used, there shouldn't really be any sonic difference at all between balanced and unbalanced unless you have a radio station emitter on the side - I mean, in term of muddiness and such.

If you have two signals and one is louder, Fletcher-Munson will apply so higher and lower freqs will stand out more with the loudest one (perhaps that's exactly what you were referencing to); and therefore any midrange (mud) will subjectively stand out more with the less loud signal.

So in general you should aim for the same loudness when you compare.
Even if your monitor gain knobs are at zero, you can turn down the playback volume to lower down the integrated loudness when you use the "louder" interface to get (whereabouts) similar levels, to compare the sound. Or you can do two bounces of the same recording, one less loud than the other.

Also since it's two different hardware devices, check out that Windows is not tricking you, as level and sound effect settings are per-device, so it's not a given they are the same when you swap..
User avatar
CS70
Jedi Poster
Posts: 6048
Joined: Mon Nov 26, 2012 1:00 am
Location: Oslo, Norway
Silver Spoon - Check out our latest video and the FB page

Re: Technical question regarding +4 vs -10 on moniotrs

Postby James Perrett » Mon Aug 10, 2020 2:07 pm

ef37a wrote:
There would seem to be a market for a Stereo Booster? Takes anything from 0dBu to +10 and cranks out +20dBu 'properly' balanced. Mr Orchid?

There used to be a few of these around. I have 24 tracks worth of level convertors sitting in the studio that came with my Fostex G24 and I seem to remember Tascam having something similar.

I see ART still make one...

https://artproaudio.com/product/cleanbo ... converter/
User avatar
James Perrett
Moderator
Posts: 9654
Joined: Mon Sep 10, 2001 12:00 am
Location: The wilds of Hampshire
JRP Music - Audio Mastering and Restoration. JRP Music Facebook Page

Re: Technical question regarding +4 vs -10 on moniotrs

Postby resistorman » Mon Aug 10, 2020 2:39 pm

James Perrett wrote:
ef37a wrote:
There would seem to be a market for a Stereo Booster? Takes anything from 0dBu to +10 and cranks out +20dBu 'properly' balanced. Mr Orchid?

There used to be a few of these around. I have 24 tracks worth of level convertors sitting in the studio that came with my Fostex G24 and I seem to remember Tascam having something similar.

I see ART still make one...

https://artproaudio.com/product/cleanbo ... converter/

Ebtech makes them too.

https://www.sweetwater.com/store/detail ... el-shifter
User avatar
resistorman
Frequent Poster
Posts: 1017
Joined: Sun Nov 22, 2015 1:00 am
Location: Asheville NC

Re: Technical question regarding +4 vs -10 on moniotrs

Postby Hugh Robjohns » Mon Aug 10, 2020 2:45 pm

There are dozens of different -10dBV to +4dBu (and vice versa) consumer/professional converters on the market, but I don't think that's quite what Dave was thinking of.

Rather, I think he was pondering a device that would convert the often restricted output levels of some of the budget interfaces to full professional levels... but this seems rather unnecessary to me.

There are few, if any, situations where a budget amateur installation will required to interface with high-end professional gear that really demands +24dBu peak levels... Most of the time not hitting those peak levels just means working with some extra headroom, which is hardly a bad thing.

More to the OP's specific point, I cant't think of any active monitors -- budget or high-end -- that requires +24dBu levels.

Nor any that would be the slightest bit bothered whether the source featured symmetrical or impedance-balanced outputs.

I really don't think the interface's peak output level capability has anything to do with the OP's problem. I am more persuaded by the possibility of a software configuration/user setup error...
User avatar
Hugh Robjohns
Moderator
Posts: 28322
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Technical question regarding +4 vs -10 on moniotrs

Postby James Perrett » Mon Aug 10, 2020 3:05 pm

Hugh Robjohns wrote:Rather, I think he was pondering a device that would convert the often restricted output levels of some of the budget interfaces to full professional levels... but this seems rather unnecessary to me.

There are few, if any, situations where a budget amateur installation will required to interface with high-end professional gear that really demands +24dBu peak levels... Most of the time not hitting those peak levels just means working with some extra headroom, which is hardly a bad thing.

I see what you mean Hugh.

The only time I've ever needed more level from my Zoom U-44 was when I was trying to use it to drive a Dolby decoder so I'd agree that this is a rare occurrence. I solved the problem by feeding the digital input and output to a Sonifex ADDA which can handle the levels that the Dolby decoder uses.
User avatar
James Perrett
Moderator
Posts: 9654
Joined: Mon Sep 10, 2001 12:00 am
Location: The wilds of Hampshire
JRP Music - Audio Mastering and Restoration. JRP Music Facebook Page

Re: Technical question regarding +4 vs -10 on moniotrs

Postby ef37a » Mon Aug 10, 2020 4:47 pm

resistorman wrote:
James Perrett wrote:
ef37a wrote:
There would seem to be a market for a Stereo Booster? Takes anything from 0dBu to +10 and cranks out +20dBu 'properly' balanced. Mr Orchid?

There used to be a few of these around. I have 24 tracks worth of level convertors sitting in the studio that came with my Fostex G24 and I seem to remember Tascam having something similar.

I see ART still make one...

https://artproaudio.com/product/cleanbo ... converter/

Ebtech makes them too.

https://www.sweetwater.com/store/detail ... el-shifter

No Sir, that Ebtech is a passive, transformer based device and therefore the 'gain' you get will depend upon the source and sink impedances. I am sure the device is of good quality but not what I meant.

Yes Hugh, you have it and yes, not really necessary for the home bod most of the time (but what about those daft sods with the A80s on tother thread?) I just thought of a compact box that could put out +24dBu balanced at low (even 'zero') impedance and might be handy for driving very long lines.
With trimmable gain could still be used in a projjy studio?

Dave.
ef37a
Jedi Poster
Posts: 11998
Joined: Mon May 29, 2006 12:00 am
Location: northampton uk

Re: Technical question regarding +4 vs -10 on moniotrs

Postby Hugh Robjohns » Mon Aug 10, 2020 5:04 pm

ef37a wrote:No Sir, that Ebtech is a passive, transformer based device and therefore the 'gain' you get will depend upon the source and sink impedances.

Yes, but only slightly... Not enough variation to be a problem in practice given the commonality of low source and high destination impedances in modern equipment.

...what about those daft sods with the A80s on tother thread?

I can't imagine they would be using budget USB interfaces anyway, so not a problem... ;-)

I just thought of a compact box that could put out +24dBu balanced at low (even 'zero') impedance and might be handy for driving very long lines.

A 12dB hotter signal level isn't really going to make any difference on any long lines in a typical home studio -- they just aren't going to be long enough to cause problems.

I understand why the relatively low maximum level bothers you... but I think it's just one of those things that really doesn't matter to most, and for those for whom it would matter, they will be using gear that works to the full spec* anyway.

*Note: the EBU spec is for a Maximum Permitted Level of +18dBu (with an alignment level of 0dBu), rather than the SMPTE's +24/+4dBu references. I use the EBU +18/0 alignment here as that suits the RME interface card I use, as well as my classic twin-twin BBC PPMs! ;-)
User avatar
Hugh Robjohns
Moderator
Posts: 28322
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Previous