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Topic: Level mismatch solutions - fixed and variable attenuators

Level mismatch is a continuing topic on our forum and support line. The most often reported problem is that active monitors are far too sensitive. The low volume click and pop when turning a unit on/off turns into a quite loud one. A volume control pot then has a very limited operation area, and the master fader in TotalMix has to be lowered to below -20 dB constantly. This also raises concerns about reduced audio resolution. With such a level mismatch hum and noise can also become audible.

What needs to be done in such cases is to make the connected amplifier or speakers/active monitors as insensitive as possible. Ignore whatever the current setting print on the monitor says, choose one that makes them as low in volume as possible.

Some customers encounter situations where this is not enough. We heard of professional and very powerful active monitors using a reference level of +4 dBu, which seems to equal full output power. Setting an RME unit to -10 dBV, which equals +4 dBu at full output level, then again requires to lower TotalMix FX to far more than -20 dB to be able to work at a typical studio listening level - plus having all the above disadvantages/problems.

The solution here is to use passive level attenuation between the RME interface and the amp/active monitor's input by a simple voltage divider, built of 2 (unbalanced) or three (balanced) resistors per channel. Do a Google search for 'line level audio attenuators' or just 'audio attenuators', and you will realize that this is not a RME problem, but a long time classic found everywhere - even in home HiFi. And this is also the reason that the web is not only full of examples on how to build such parts, including the part values and circuit diagrams, but why they are also available at reasonable prices in various models from various manufacturers.

If you don't want to waste your time with ordering parts, soldering, and drilling housings, here are two solutions that have been tested to work perfectly with RME devices:

For balanced outputs: JTS Mic attenuator MA-123, XLR to XLR, available for around 20 €, switchable attenuation of -10, -20 and -30 dB. Don't get confused with the term 'mic attenuator'. It works perfectly with line outputs. In fact it works even better as other 'line' solutions, because its impedance is high enough for the RME output stages to not cause distortion (1 kOhm), but very low for any following device (below 200 Ohm), which means there is no added low level noise and no high frequency rolloff caused by cable capacitance when plugged into the output of the RME device. Of course, cable influences can be ruled out completely even with higher impedance attenuators by plugging them directly into the amp/monitor's input jack - at the end of the cable.

For unbalanced outputs: IMG Line attenuator ILA-1020, RCA to RCA, switchable attenuation of -10, -15 and -20 dB. One pair is available for around 25 €. Note that these use much higher resistor values than the balanced ones, more than 10 kOhm input and around 1 kOhm output. Therefore they should be placed directly at the input of the receiving unit, not at the output of the sending one.

These are just two examples. There exist many other, like:

Balanced:
Hosa ATT448
Pro Co Max20
Audio-Technica AT8202
Shure A15AS

Unbalanced:
Rothwell RCA attenuators
Harrison Labs RCA Line level attenuators

Another way to solve the level mismatch is by adding a variable resistor (aka potentiometer) instead of the fixed ones. Put the pot into a desktop housing and you have a variable volume control. These are also very popular, examples:

SM Nano Patch +, also available from JBL
Palmer Monicon

They have a few advantages: volume controlled from your desktop, mute switch provided, also serves as format adapter as it provides XLR, TRS and small TRS stereo on input and output simultaneously. The current generation uses quad potentiometers, so work both balanced and in stereo, and are also automatically compatible to unbalanced operation. All passive!

Compared to the above fixed low impedance resistor solutions the variable ones have a technical disadvantage - they use pots with 10 kOhm resistance, 10 times as much as the 'mic' attenuators. Ideal they would use 1 kOhm pots, but maybe decided for higher values as some devices have much higher output impedances as RME units. With 10 kOhm and the pot in the middle position a series resistor of 5 kOhm is in the signal path, and a parallel one of 5 kOhm works as load. Depending on the used cables and input circuitry a slightly increased noise floor as well as a slight high frequency damping might occur. In real-world operation and usage user feedback is very positive when using these devices.


Background information:

RME interfaces and converters provide several, user adjustable output levels, from -10 dBV up to +24 dBu. Most devices support +19 du, +13 dBu and +4 dBu (aka -10 dBV). Some devices like the Babyface and Babyface Pro do not support different ref levels at their outputs, for example the BF Pro XLR outputs are fixed at +19 dBu. As explained in the manuals a digital fullscale level in -10 dBV setting does not equal -10 dBV, but +2 dBV, or coarsely +4 dBu. The reason is that analog equipment, especially mixing desks working with this reference level, offer a very high headroom - not astonishing, as the internal circuitry ist still running with +-15V, the same voltage that is used for +24 dBu output level stages. We therefore defined our -10 dBV setting with 12 dB of headroom.

The attenuation required in mismatch cases as described above is typically -20 dB.

Regards
Matthias Carstens
RME

Re: Level mismatch solutions - fixed and variable attenuators

Many thanks !

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

Re: Level mismatch solutions - fixed and variable attenuators

That is a great article...thank you.

Babyface Pro, UFX+ via Thunderbolt, Win 10, Cubase 9.5 Pro, Asus Z270 i7700k Guitarist-1961

4 (edited by Markk786 2017-08-13 14:43:35)

Re: Level mismatch solutions - fixed and variable attenuators

Thanks a lot....!!!
subchorionichematoma

Re: Level mismatch solutions - fixed and variable attenuators

MC wrote:

For balanced outputs: JTS Mic attenuator MA-123, XLR to XLR, available for around 20 €, switchable attenuation of -10, -20 and -30 dB.

Where to even get these? Thomann doesn't hold them, and Monacor seems to be way too slow to authorize new webstore accounts, they don't even allow to browse the shop without logging in (lame).

Any other solutions are more than twice expensive (Shure, AT, especially Hosa) so I'm not interested in them. This JTS seems like just the ticket, but googling around, it's hard to find ANY shops that hold them! What gives? hmm

A very happy RME UFX+ & ARC owner smile

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Re: Level mismatch solutions - fixed and variable attenuators

Geht's hier um Deutschland/Europa? Dann kann ich nur sagen schlecht gesucht. Amazon.de hat zwar aktuell nur einen, Conrad aber jede Menge für 18,90. Etc etc...

Regards
Matthias Carstens
RME

7 (edited by EvilDragon 2017-10-15 17:45:35)

Re: Level mismatch solutions - fixed and variable attenuators

Croatia here, so EU, yeah...

Saw it available at Conrad.de, but they don't ship to Croatia (no options to enter a Croatian address in their webshop checkout). They do have a Croatian website, but no MA-123 on it available to order, at all (not sure why!)... sad

A very happy RME UFX+ & ARC owner smile

Re: Level mismatch solutions - fixed and variable attenuators

Just send a mail to the Croatian Conrad site and ask for the Conrad.de item.

The same happens with the Conrad.be site. They just don't have every item listed. Usually, they"re happy to add anything and a while later it'll be listed too.

MB Pro - 2 X FireFace 400, FF800 & DigiFace USB
ADAT gear: Korg, Behri, Fostex, Alesis...

Re: Level mismatch solutions - fixed and variable attenuators

Thanks, I think I'm gonna do that smile

A very happy RME UFX+ & ARC owner smile

Re: Level mismatch solutions - fixed and variable attenuators

If you ever liked a (over) priced solution, but one that looks unmistakably cool and stilish, and runs smooth as melting butter, here is one I've been using since ever, for this very purpose: http://www.tcelectronic.com/level-pilot/.  I find it easier to grab than turning the BabyFace Pro dial-wheel in a hurry-up occurence: it's closer, it sticks out, you grab it even if blindfolded, and it's never assigned to the wrong pair of outputs, or inputs, ever.

My case was as typical as all others here: amp on full input level was way too loud to make any sense, and yes, it's not RME's fault, not in the least. It's an evergreen, classic audio topic, that's been on any schooldesk ever since, for students and teachers alike to deal with, and solve. Like MC correctly points out, correct as ever, there's cheaper and cheapest solutions that do the job great, for peanuts. In my instance, cheap is often seen as wrong, even when it works great, so to dispel any doubt, expensive just means assuringly good (if it works, at least).

Pot works great, and it's also fairly even between channels, and at modest rotation angles, too, which, in my view, justified and justifies the hefty price: if lowering the program to whisper-level volume makes channels uneven, that's what spoils the whole effort. With this one, it doesn't happen, balance stays true, and that's what counts here.

What I can't forgive the maker for, though, are the connectors, of a cheaper-than-cheapest sort: for the price it sells (on average street level), it might as well have had Neutrik XLR connectors soldered at the end of the cable, and with a proper color coding scheme, none of which has been provided by the manufacturer.

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Re: Level mismatch solutions - fixed and variable attenuators

I overlooked that one, thanks. Would be nice to know how much Ohms the pot in it has. Also ESI just announced the new MoCo

http://www.esi-audio.de/produkte/moco/

which is comparable to the mentioned NanoPatch and Monicon units, and (not mentioned) others like the Mackie Big Knob Passive, the Swissonic M-Control and whatever there might exist. The MoCo now has a big variety of I/O connectors (therefore also serves as jack format converter) and all the buttons one could want. Its design might not fit everyone, though.

The desktop pot solution is giving extra features, but this review of the MoCo reminds German readers that those units do introduce level mismatches over the pot range, reduce channel separation a bit, and (due to the higher Ohm pot) even might introduce a  little noise:

https://www.bonedo.de/artikel/einzelans … -test.html

Something you won't see with the more simple level attenuators and a digital volume control.

Regards
Matthias Carstens
RME

Re: Level mismatch solutions - fixed and variable attenuators

MC wrote:

I overlooked that one, thanks. Would be nice to know how much Ohms the pot in it has.

just looked it up on ggl, searched for "bourns pot resistance tc level pilot". search returned a funny salesforce page (helpdesk material, most likely from manufacturer) saying it's a 4*10k log one.

opened up the thing, peeped at the blue plastic box of the pot, stamped across is 410K, which sounds consistent to the .pdf datasheet shared by manufacturer when users ask for pot replacement.

so 10k it is, a 4-wires Bourns PTD 904 - 1020K-A103.

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Re: Level mismatch solutions - fixed and variable attenuators

Ok, I better not ask you about details of RME devices wink

Regards
Matthias Carstens
RME

Re: Level mismatch solutions - fixed and variable attenuators

Thanks Matthias for this very helpful article.

Mac/PC => USB/Toslink => customized DAC => RCA => Yamaha R-S700 => copper cables => JBL 4313B

15 (edited by FIXXXER 2017-12-25 22:07:02)

Re: Level mismatch solutions - fixed and variable attenuators

MC wrote:

What needs to be done in such cases is to make the connected amplifier or speakers/active monitors as insensitive as possible. Ignore whatever the current setting print on the monitor says, choose one that makes them as low in volume as possible.

at this point everything is set to 0dB on my ADAM P11A active speakers.
so you do recommend to turn down the input gain to -10dB?

https://s1.imagebanana.com/file/171225/4Boe7Z2y.jpg

16 (edited by ramses 2017-12-25 22:24:33)

Re: Level mismatch solutions - fixed and variable attenuators

Yes, better there with an analog vol poti.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

Re: Level mismatch solutions - fixed and variable attenuators

Thanks for this info. I'm running genelec a pair of 1029a... Have set the gain right down low on the front of the monitors, and seems to be running fine, but my speaker b (running out of ph 3.4 3.5mm on babyface pro) (small bluetooth speaker guy) seems to need more juice, so I'm finding the output is overloading on the headphone output to get a matched level on the reference (speaker b)... I'm not sure if there is a better way to match the speaker b output level without buying the attenuators... They're about $30 each in AUS, + postage... Not too expensive, but not peanuts...

Is there a way to set the output to speaker b without overloading the output in totalmix? Sorry if this info is not clear, happy to answer any qualifying questions..

Also, the attenuators look kind of long, I'm thinking they may stress the output sockets, especially once you hang xlr cables off them at the back of the babyface pro... Could you just plug them into the back of the monitors instead? Am I missing something here?

Thanks for your help. Loving the quality of the BBFpro... Everyone's emphatic encouragement for RME quality is well deserved.

Re: Level mismatch solutions - fixed and variable attenuators

This is a Great page for making your own  PADS
http://www.uneeda-audio.com/pads/

Ive made a fixed pad only with 3 resistors for each pad. ive a RME UCX and  ADAMS A7Xs.

Re: Level mismatch solutions - fixed and variable attenuators

gimenezex wrote:

This is a Great page for making your own  PADS
http://www.uneeda-audio.com/pads/

Ive made a fixed pad only with 3 resistors for each pad. ive a RME UCX and  ADAMS A7Xs.

neat site, wise words... thanks for the tip, makes for a useful recount, or reading!

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Re: Level mismatch solutions - fixed and variable attenuators

Does this work with every interface (also from other manufactures) or is the "impedance thing" different?
For example my setup:
Raydat>Apogee Symphony>Box

Totalmix via RME ARC
Is the JTS Mic attenuator MA-123 the way to go?

21 (edited by Vicente 2019-01-10 15:15:53)

Re: Level mismatch solutions - fixed and variable attenuators

Hi folks,

Just wanted to confirm that the JTS MA-123 mic attenuator works perfectly with the Babyface Pro. I've tested all three attenuation positions (-10, -20 and -30bB) and ballistics of the LED meters have improved considerably making use of most of the 24 bit resolution without destroying your eardrums. My Genelec 8040A's sensitivity is set to +6bBu and I can comfortably crank the TotalMix master fader above -20dBFS. 0dBFS is glorious, but it depends on how much you're willing to bother your neighbors! big_smile

You can definitely listen to the higher definition of the sound when using the full 24 bit resolution of your interface. A lengthy post in the Gearslutz forum discusses this level mismatch as well. Composer Charlie Clouser (Saw movies and a veteran of digital audio) participated in the thread and insisted on using as much digital resolution as possible to get all the detail from your speakers while mixing.

On the other hand, I also wanted to point out that the correct specifications for the JTS MA-123 are 1,6 kOhm for input impedance and 660 Ohm for output impedance. You can check them at their official website. Since the administrator gave different figures I asked RME support about this because I'm no electrical engineer - good music is already difficult to create, thank you very much - and I don't know if this discrepancy is relevant. Unfortunately, I didn't get a response to my last email... which is quite disappointing. I'm certainly satisfied with the superb audio quality of this interface, the rock solid drivers, and the impeccable software that comes with it, but not answering a customer's inquiry is both impolite and unprofessional.

Good luck!

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Re: Level mismatch solutions - fixed and variable attenuators

The JTS impedance varies a bit depending on the used attenuation. And honestly we are not the support for third party tools.

Regards
Matthias Carstens
RME

Re: Level mismatch solutions - fixed and variable attenuators

Sorry I didn't get round to replying to that mail yet, had a few long phone calls yesterday.

As for "losing resolution", a) I would doubt that you can really hear it (more volume does not mean more resolution), and digital attenuation does not actually lose "resolution" (as in LSB accuracy of the DA), it only lowers S/N ratio somewhat. But even that is only theoretical and not audible, as long as you don't massively attenutate digitally and then amplify in the analog domain again. If you just attenuate digitally, the DA's noise level does not increase in absolute terms.


Regards
Daniel Fuchs
RME

Regards
Daniel Fuchs
RME

Re: Level mismatch solutions - fixed and variable attenuators

sorry for the noob question. i have a babyface pro and a pair of focal shape 50. these monitors dont even have any volume adjustment so i m using the babyface in very low db settings in totalmix (-30, -40 db,i also like to mix with low volumes) do i lose anything in terms of resolution or audio quality in general?

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Re: Level mismatch solutions - fixed and variable attenuators

Do you hear a constant low volume noise out of the Focals? That would be the limitation in 'resolution', as it might cover even lower volume audio. But even if not the reasons outlined in post 1 should make you order the JTS adapters.

Regards
Matthias Carstens
RME

Re: Level mismatch solutions - fixed and variable attenuators

MC wrote:

Do you hear a constant low volume noise out of the Focals? That would be the limitation in 'resolution', as it might cover even lower volume audio. But even if not the reasons outlined in post 1 should make you order the JTS adapters.

no everything is quiet and clean, i have zero issues working with very low DB values

27 (edited by integra 2019-01-24 14:27:46)

Re: Level mismatch solutions - fixed and variable attenuators

MC wrote:

Background information:

RME interfaces and converters provide several, user adjustable output levels, from -10 dBV up to +24 dBu. Most devices support +19 du, +13 dBu and +4 dBu (aka -10 dBV). Some devices like the Babyface and Babyface Pro do not support different ref levels at their outputs, for example the BF Pro XLR outputs are fixed at +19 dBu. As explained in the manuals a digital fullscale level in -10 dBV setting does not equal -10 dBV, but +2 dBV, or coarsely +4 dBu. The reason is that analog equipment, especially mixing desks working with this reference level, offer a very high headroom - not astonishing, as the internal circuitry ist still running with +-15V, the same voltage that is used for +24 dBu output level stages. We therefore defined our -10 dBV setting with 12 dB of headroom.

The attenuation required in mismatch cases as described above is typically -20 dB.

Not realy understand +4dBu equal to -10dBV? or???

Usable link for levels compare http://www.sengpielaudio.com/calculator-db-volt.htm

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Re: Level mismatch solutions - fixed and variable attenuators

It's about headroom and explained in detail in the manuals.

Regards
Matthias Carstens
RME

29 (edited by integra 2019-01-25 09:44:55)

Re: Level mismatch solutions - fixed and variable attenuators

Its explane mistake?
Termin Headroom and him correlation with analog output is not aplicable for understand what output modes user need switch on.
Only one thing need to be understand for all users is simple formula.
Example for +4dBu setup.
Switch output trim +4dBu. This ecual to 0dBfs=1.23V RMS on the balansed outputs. Point.
Another words. Maximum level in digital domen = maximum Volts RMS for outputs with choised output level.
If user have amplifier/monitors ets with input sensitivity -10dbV(316mV RMS) its not a problem. Decrease volume for Minus 8dB for +4dBu setup. But this is not good for use volume knob on the DAC. User must be see on the dislay each time when increase volume for overload reason.
For all use online calculator.
For better compatible with consumer devices and stop many discussion about levels compabilyties RME need to be add 2 program points in the out menu. For 0.775 and 1 volts devices and include adapters XLR-RCA in the shipping bundle. Many(all) adapters on the market shorted 3 and 1 pins and not aplicable for RME main out for non servobalanced circut reason.

Re: Level mismatch solutions - fixed and variable attenuators

I turn my Yamaha HS5s' level to nearly zero and now I can definitely work at about 0 dB both "software playback" and "AN1/2". It kinda solve the issue even though I didn't buy an attenuator.

But that arouse another issue that now I have to turn down the MDR-7506 (PH3/4) to -23 dB to have a reasonable listening volume,
and I wonder if that would reduce my PH3/4's resolution. I don't think the above mentioned attenuator method could solve the problem, either.

So is there a workaround for the overly loud headphone?

regards,
Seb

31

Re: Level mismatch solutions - fixed and variable attenuators

You don't loose resolution, so no workaround needed.

Regards
Matthias Carstens
RME

32 (edited by bbaasszz 2019-01-30 00:13:07)

Re: Level mismatch solutions - fixed and variable attenuators

Hi, thanks for the reply.

and the master fader in TotalMix has to be lowered to below -20 dB constantly. This also raises concerns about reduced audio resolution. With such a level mismatch hum and noise can also become audible.

So do you mean this is just a waste of worry and isn't true for all the RME interfaces? It's really good to know if that's the case.

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Re: Level mismatch solutions - fixed and variable attenuators

The resolution thing is misunderstood quite often. Uh, it's only 10 bits left and will sound distorted as hell. Do the test yourself: reduce the level to say -50 dB, analog loopback, record the analog signal, then normalize level. The music will sound phantastic, but naturally with a low level, constant and audible noise floor (from DA and AD conversion). But there is zero loss of information, space, sound stage, bass/mid/treble still in full glory, and most important there is zero distortion added. As long as you can't hear the noise floor anyway - what did you loose?

Regards
Matthias Carstens
RME

34 (edited by bbaasszz 2019-01-30 03:22:33)

Re: Level mismatch solutions - fixed and variable attenuators

MC wrote:

The resolution thing is misunderstood quite often. Uh, it's only 10 bits left and will sound distorted as hell. Do the test yourself: reduce the level to say -50 dB, analog loopback, record the analog signal, then normalize level. The music will sound phantastic, but naturally with a low level, constant and audible noise floor (from DA and AD conversion). But there is zero loss of information, space, sound stage, bass/mid/treble still in full glory, and most important there is zero distortion added. As long as you can't hear the noise floor anyway - what did you loose?

Yes, I just watched a clip recently, in which Ian Shepherd explained the only difference between 24 bit vs. lower bit (say 8 bit) audio is the noise, while the signal will remain intact.
https://www.youtube.com/watch?v=Rc_-eavKptY

So now can I conclude that the whole Totalmix Fx is a digital mixer (including all faders), and that by lowering my PH3/4 down to -18 dBFS, I'm acctually lowering the device's bit-depth from 24 to 21?

35

Re: Level mismatch solutions - fixed and variable attenuators

Phantastic video - something like this was missing for a long time! While he is doing it fully digital it stays true when doing it via analog loopback. AD/DA will add their own noise, but the music stays the same.

BTW, your device's bit depth is below 21 bit (we are talking about the analog monitor output), limited by the noise floor of the DAC - if you look at the dynamic range as 'bit depth'.

Regards
Matthias Carstens
RME

36 (edited by all 2019-03-22 20:26:42)

Re: Level mismatch solutions - fixed and variable attenuators

hi !

i discovered this topic just now. well, i'm actually, with ufx on 3 focal solo 6be, small rom, in a situation of typically fader master at -17/-20 with ufx master set at +4dBu and focal on the lower setting aka +4db. No particular pb here, for years. after reading this, JUSTE FOR FUN : i did a comparaison between my old -17 at +4dBu and a new -8 at -10dbV, and then it seems the same volume (focals remain unchanged). so i was wondering what to think ? to my hears same volume, no hum or nothing in any case... (scratching my head....)

Re: Level mismatch solutions - fixed and variable attenuators

Hi there! I will soon receive my Neumann KH 310 monitors. They will be driven by the RME ADI-2 DAC.

I have two questions regarding this thread:
1) In order to match the level, is it better to put the Neumann pot to -15 dB, or to put it at 0 dB with JTS Mic attenuator MA-123?
2) Where must I plug the attenuator in such case? Directly to the speaker or after a short cable (in order to not damage the speaker plug)?

Many thanks. smile

ADI-2 DAC (with stock PSU) - Neumann KH 310 A monitors - Cheap USB and XLR cables

38 (edited by ramses 2019-07-18 16:08:56)

Re: Level mismatch solutions - fixed and variable attenuators

Thanks for the tips Matthias. The JTS Mic attenuator MA-123 works perfect for me in -30 dB setting.

Very good price compared to the others.
Quality and flexibility in settings: -10 / -20 / -30 dB.

The Setup: ADI-2 DAC as preamp for the poweramp section of Accuphase E-600 (30W Class A).
The JTS Mic attenuator MA-123 works perfect for me in -30 dB setting.
On the ADI-2 DAC I am using:
- Auto Ref Level ON
- Low Vol Ref: -40 dBu (for dynamic loudness)
- Level: -20dB (+1dBu), as start value (before dynamic loudness kicks in)

As I do not need my turntable at the moment I will use this setup now for a while.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

39 (edited by berme_1 2019-08-07 18:03:21)

Re: Level mismatch solutions - fixed and variable attenuators

Thank you for this thread!

I have exactly this problem.  Even with my monitors turned down to -10dB AND the Level on the settings tab of TotalMix's Main Out set to -10dB, if the the mix in my DAW is outputting anything above -6dB and the main out of TotalMix is set to 0dB, the sound output is ear splitting.  So I end up monitoring with TotalMx turned way down to -25 or -30dB.  Especially when playing back commercial reference tracks which have been compressed to commercial loudness levels.

My search for a solution had me looking at very expensive third party monitor controllers in order to get the transparency I want.  But even they aren't ideal.  The only protection is that it's more unlikely to twist a knob to max by mistake, and the knob is easily available in case of an unexpected sudden volume jump in software.  But they don't actually limit the ability of the system to reach excessive levels.

And then I found this thread.  An in-line attenuator that will actually physically limit the maximum possible output, with little to no sound quality degradation, all for around $50 each.  So elegant.  Thank you.

FYI for RME - I understand this thread essentially promotes other companies' products, BUT - if I can solve the output level problem with one of these attenuators, then I can buy the RME ARC USB for monitor control instead of a third-party monitor controller.

Anyway - it's such an extraordinarily good solution that it seems almost too good to be true.  So, just to reassure myself, can I double check a few details?

1. In the OP, MC says:

MC wrote:

"...here are two solutions that have been tested to work perfectly with RME devices...JTS Mic attenuator MA-123, XLR to XLR, ... It works perfectly with line outputs. In fact it works even better as other 'line' solutions, because its impedance is high enough for the RME output stages to not cause distortion..."

To be specific, I have an RME Fireface UFX.  This unit:  https://www.rme-audio.de/en/products/fireface_ufx.php

Would the JTS be as ideally suited to this unit as described generally?

I case it matters, my monitors are Dynaudio BM5a MkII.

2. Regarding transparency - I also found another thread discussing this.  When asked about the JTS attenuators introducing distortion or coloration, RME replied:
https://www.forum.rme-audio.de/viewtopi … 02#p143402

MC wrote:

I have measured these several times, THD is below the measurable limit, around -140 dB (0.00001%). Their numbers show the usual problem of getting more noise into the measurement the lower the level.

These are simple resistor dividers that don't change the frequency response, do not add noise nor distortion. The achieved attenuation might be some dBs off due to the source devices' output impedance, but that's for overall volume, and not sound changing.

I know it's right there in black and white - but just wanted to double check - really?  This good?  I'm just surprised because to get a transparent monitor controller is very expensive.

3. Alternate Units - I've checked out a couple of  the similar items mentioned in the OP:
Audio-Technica AT8202 - specs here:  https://www.audio-technica.com/cms/elec … index.html
Shure A15AS - full specs here:  https://pubs.shure.com/guide/A15AS/en-US

Both input impedance of 1k-Ohm and output impedance of 175 to 200 Ohm.  A bit different from the JTS.  So I'm wondering -  is it that, in theory, they should be fine also?  Or have they been tested and confirmed to work just as good (ie, transparent)?  Or are the JTS's the only ones that RME has actually tested and confirmed work very well - in which case I'll stick with that.

Thank you again.

Re: Level mismatch solutions - fixed and variable attenuators

> FYI for RME - I understand this thread essentially promotes other companies' products, BUT - if I can solve the
> output level problem with one of these attenuators, then I can buy the RME ARC USB for monitor control
> instead of a third-party monitor controller

Yes.

I got the recommended JTS myself, it's robust, flexible (-10, -20, -30) and works very well:
https://www.thomann.de/de/jts_ma_123.htm

The ARC USB gives you then some value on top for your UFX. Good decision.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

Re: Level mismatch solutions - fixed and variable attenuators

ramses wrote:

> I got the recommended JTS myself, it's robust, flexible (-10, -20, -30) and works very well...

Thank you for the reassurance.

Re: Level mismatch solutions - fixed and variable attenuators

In this thread:

https://www.forum.rme-audio.de/viewtopi … 30#p144230

we discussed achieving headphones output attenuation internally by doing this:

open the Dynamics tab, turn it on, set the compressor and expander ratios to unity and turn down the input Gain

Then the volume fader can be turned up just as with an external attenuator. 

Two questions about this:

a) On the one hand, it avoids introducing additional external circuitry to the signal path.  On the other hand, I don't know what it might do to the signal internally.  In terms of retaining the best, unlatered, sound quality, which do you think is the better solution?

b) How about reliability?  A simple resistive external hardware attenuator is very unlikely to ever fail.  Does it seem at all likely that TotalMix would ever just 'forget' the Gain setting, or fail to set it on start up?

Thanks.

43

Re: Level mismatch solutions - fixed and variable attenuators

a) We are not talking about lowering the volume and then re-recording that analog signal - that would be a bad idea. On monitor or phones outputs digital volume control is (these days) transparent and shifts the signal into the noise floor without any coloration or distortion. So as long as you can't hear the noise floor the limiting factor is not the reduced dynamic range (from lowering the digital signal's volume), but your ears. They can not hear the super low level parts anyway, and that's why you don't need to worry about it.

b) TotalMix does not reset itself automatically. Only you can cause such a reset, which might happen more quickly than you like by playing around with it...

Regards
Matthias Carstens
RME

Re: Level mismatch solutions - fixed and variable attenuators

MC wrote:

....TotalMix does not reset itself automatically. Only you can cause such a reset, which might happen more quickly than you like by playing around with it...

:-)  Ha ha - yes, there's always the fallibility of the human user.

Anyway - So - using the Dynamics tab Gain to attenuate output is built-in, transparent without any coloration or distortion, undiscernable unless I attenuate way down into the noise floor (I'm only going ~-20dB on both monitors and headphones) , free, and the only flaw in reliability would be if the user makes a change himself?

I believe I have my solution.

Thank you for your help.

Re: Level mismatch solutions - fixed and variable attenuators

I got myself some JTS Mic attenuator MA-123's to use with my Fireface 802, but recently I also installed a Genelec 7070a subwoofer which is rated to go down to 19hz.
Yet the JTS MA-123 spec sheet tells it has a frequency range of: 22 - 20,000 Hz.
Could this be a bottleneck for subs or just some technical nonsense.

Cheers!

Re: Level mismatch solutions - fixed and variable attenuators

I'm having issue with Neumann KH120 being extremely loud. I set the input gain to lowest settings (0 db) on the back on the monitor and output level to lowest (94 db SPL).

If i go into total mix and set master to -10dbV its going back to more acceptable level but when i put into DAW mode its ear splitting.

Is the solution an attenuator?

47 (edited by Manuel 2020-11-19 00:25:06)

Re: Level mismatch solutions - fixed and variable attenuators

Great thread! I'm a bit confused though, @MC, in your first post you said:

MC wrote:

A volume control pot then has a very limited operation area, and the master fader in TotalMix has to be lowered to below -20 dB constantly. This also raises concerns about reduced audio resolution.

But in a later post you said:

MC wrote:

On monitor or phones outputs digital volume control is (these days) transparent and shifts the signal into the noise floor without any coloration or distortion. So as long as you can't hear the noise floor the limiting factor is not the reduced dynamic range (from lowering the digital signal's volume), but your ears. They can not hear the super low level parts anyway, and that's why you don't need to worry about it.

So is reduced audio resolution something I should worry about or not? I'm happy to use passive attenuation as per your recommendation but if I'm connecting my headphones directly to my audio Fireface UFX I have no choice but to adjust the level in Totalmix.

Fireface UCX II, BabyFace Pro, Fireface UFX, Fireface 400

48

Re: Level mismatch solutions - fixed and variable attenuators

1. No. 'it raises concerns' for some users, not me.

2. The UFX has two hardware based ref levels for its phones outputs (equalling a -15 dB attenuator). Problem solved...

Regards
Matthias Carstens
RME

Re: Level mismatch solutions - fixed and variable attenuators

MC wrote:

1. No. 'it raises concerns' for some users, not me.

2. The UFX has two hardware based ref levels for its phones outputs (equalling a -15 dB attenuator). Problem solved...

Nice—that will save me a bit of money smile

Fireface UCX II, BabyFace Pro, Fireface UFX, Fireface 400

Re: Level mismatch solutions - fixed and variable attenuators

I just bought a couple of Tannoy Gold 5 to pair with my Babyface Pro, good value for the price but, damn, they are sensitive as your ex-girlfriend.
I confirm that the JTS Mic attenuator MA-123 does the job. With -30 dB attenuation I still don't need to push the speaker level past 1/4 for nearfield listening, but at least I can set the interface to 0 dB and take advantage of all the headroom or put it at -6 to -10 for casual listening/background music.
Also the noise level coming from the speakers is significantly less.