Setting wireless lavs for dialog (mic level vs. line) what's your preference?

[Tom Visser]

I'm all one for setting line level (or utilizing AES when available) but to play devil's advocate, many mixers utilize a simple pad in front of a mic preamp when set for line level input, so no matter how you slice it, you may in fact be padding a line level signal down to mic level either way.  If the cable runs are short, cabling is adequately shielded, there may be circumstances where mic level will simply sound better, whether due to input transformers, or aesthetic of the opamp in the mic preamp stage, or ability to utilize input limiters that are not active on line stages, etc...

[chris_bollard]

I understand the line setting gain structure thing - but with SD 633 you really need to run the Rx at mic level to have enough oomph. That's the problem with inputs 4-6

[RPSharman]

Certainly if you need more gain, then it can make sense. Or you're using inputs 1 & 2 on 744T with no mixer in front. Or if you're using a mixer or recorder whose line input is just a pad, and you're not getting any "noise" from the system, and it makes you feel warm and fuzzy to attenuate the receiver instead of padding the input of the gear....

But as a general rule - what Larry wrote.

[Tom Visser]

It's a thinking man's game, so as long as you are on top of things and do things for good reasons, it's all good.  For me, line all the way.

[John Blankenship]

... many mixers utilize a simple pad in front of a mic preamp when set for line level input, so no matter how you slice it, you may in fact be padding a line level signal down to mic level either way.

...

Can anyone name a single professional mixer that is designed this way? Even from a cost-cutting standpoint this design shortcut makes no sense since the invention of the opamp.

[chris_bollard]

Based on specs solely looking at the Rx line level is king - the reality of what is down stream determines how you slice it, and in the mix it would be very hard to tell the difference. +5 line on the 788; -25 to -20 mic on the 633 inputs 1-3; inputs 4-6 on 633 +5 and max menu gain on 633.

What ever works for you.

[LarryF]

Now that I've Damned "mic level" to the bowels of the underworld, here's the best way to implement mic level in the presence of ground loops, etc., without spending big bucks on isolation transformers or battery eliminators: Come out of the device (Lectro receiver or other) at line level and go down the cable at line level.  Put an attenuator at the input to your device that requires mic level, balanced or unbalanced. What this does is it puts a signal at line level on the shield or ground or common at high level that swamps the noise. When you attenuate the signal at the input device, you also attenuate the hum loop or RF picked up on the shield or ground wires.

 

For instance, assume you were dealing with a device with an Automatic Gain Control that uses an 1/8th inch jack unbalanced and it wants a -40dBm signal or the AGC starts acting up. (The very thought of this device gives me goosebumps but s*it happens). You can turn the receiver output down and if it sounds good, fine. If you are getting hum, whine or RF pickup, this following will most probably work: Come out of the receiver at line level, put a 10k Ohm resistor in series with the center conductor to the tip of the 1/8 inch plug and a 330 Ohm resistor from the tip connection to ground. This will give you 30dB of attenuation and plenty of adjustment range. The 30 dB of attenuation will attenuate hum loop and RF pickup also. This is much better than turning the receiver down 30 dB and having any noise pickup come into the input at full level. If you need 10 dB more attenuation, use a 100 Ohm resistor from tip to ground.

 

Best Regards,

Larry Fisher

Lectrosonics 

[Eric Toline]

The Headmaster of the Hogwarts School of RF Magic has spoken.

[LarryF]

The Headmaster of the Hogwarts School of RF Magic has spoken.

 

Hi Eric,

HHSRFM. -- I like it. That and a cup of coffee will get you 10 cents.

Best,

Larry F

[Jay Rose]

to play devil's advocate, many mixers utilize a simple pad in front of a mic preamp when set for line level input

 

 

 

+1 John's comment. I've never seen that in pro equipment either... except IIRC, the Sony PD150 camera from 12 years ago (which was a disaster anyway). 

 

It makes no sense with modern designs. Even if you're not using an op-amp configuration, you can still apply negative feedback to reduce the gain.

 

But even if some equipment does use a pad, it makes sense to put the pad at the -end- of the signal cable, not at the front. For reasons Larry mentioned, among others.

[Rich Reilly]

Ok..did I miss the part when OP posted the wireless used?

[LarryF]

Ok..did I miss the part when OP posted the wireless used?

Hi Rich,

I think the question, answers and application are brand independent. Am I missing something here, like a model (brand) that clips the output when at line level?

Best,

Larry F

Lectro

[Rich Reilly]

I get your point, Larry....from a strictly technical perspective. But it seems natural to include that info. And..I am curious about Jason's preference for mic level based on how he feels it sounds. Any thoughts on that? Perhaps there are impedance issues etc that might come into play depending on gear in the signal chain.

[daniel]

I understand the line setting gain structure thing - but with SD 633 you really need to run the Rx at mic level to have enough oomph. That's the problem with inputs 4-6

+1. 99% i use the line level o/p when but at times use a 'hotish' mic level o/p because the sd302 doesn't have enough gain at line level (with 411s) to use 302 i/p limiters.

[John Blankenship]

...

And..I am curious about Jason's preference for mic level based on how he feels it sounds. Any thoughts on that? Perhaps there are impedance issues etc that might come into play depending on gear in the signal chain.

I addressed the likely reason in an earlier post.

[JDirckze]

I get your point, Larry....from a strictly technical perspective. But it seems natural to include that info. And..I am curious about Jason's preference for mic level based on how he feels it sounds. Any thoughts on that? Perhaps there are impedance issues etc that might come into play depending on gear in the signal chain.

I'm curious too...

My system has changed slightly, I now have SRb's in the bag instead of 411's. Back when I made the decision to stick to Mic level I think I was using a Wendt X5 and a mix of 211's and Sony WRRxxx. Now I have a 552 & 788 (& 302, Mix Pre D). So, there are ALOT of variables in my setup.

This thread got me thinking, and I am experimenting further and have changed 1 channel of my SRb to Line and have left the other on Mic. The first day of use didn't bring up any noticeable difference in manner/quality between the two using my 552. I'll keep playing around as I'm just about to embark on an 8 month contract, so there will be plenty of time to experiment.

[Dennis Kersten]

 When linelevel is what we need, how come the audio ltd 2040 DX is mic level only? Been wondering about this for some time..

 

http://www.audioltd.com/location/dx2040-receiver-the-next-step/

[studiomprd]

DK: "  how come the audio ltd 2040 DX is mic level only? "

guess you should ask them...

[Dennis Kersten]

DK: "  how come the audio ltd 2040 DX is mic level only? "

guess you should ask them...

Mailed them right away and got a super quick response within two hours or so....   ;

 

The actual output level from the DX2040 receiver at full deviation is -26dBm, which is greater than mic but below line level.

 

It is only in the last few years that the demand for portable receivers to have line level outputs has come into play. It was only studio mounted equipment where the line level output was requisite.

 

I believe it is only sine the Sound Devices products became available that the demand for line level outs has become more of an issue.

 

We do have the headphone level output available from the DX2040 which has been successfully used by many freelancers to connect to the Cantar and also the Sound devices products. There is no penalty in quality, but it is unbalanced.

 

Also, don’t forget that the RMS2040 series was launched just over 8 years ago.

 

Hopefully we will bring out line level outputs in our next generation of systems.

[Rick Reineke]

Were not the Lectro CR-185 187 & 195 portable receivers mic level (or there about) as well?

[studiomprd]

rick: " Were not the Lectro CR-185 187 & 195 portable receivers mic level (or there about) as well? "

if you want to know, Lectro is only a toll-free call away, and actually, you can find that information on their web-site...

[LarryF]

Were not the Lectro CR-185 187 & 195 portable receivers mic level (or there about) as well?

185 and 187 were -20dBv max or 100mV. The 195 had three levels: variable up to -30 dBV, variable up to 0 dBV and fixed at + 8 dBV. We learned as the years went by.

Best,

Larry F

Lectro

[Mark Orusa]

Unless you're inputting the signal to your mixer through a line level input, like Nomad's inputs 7-10 for example, you are using the mic pre any way. Every XLR input I've used on a location sound mixer just introduces a pad for line level signals. That essentially makes your incoming line level signal mic level.

 

The point Larry makes is keep everything line level until it reaches the mixer, for many worthwhile technical reasons.

 

Mark O.

[John Blankenship]

Unless you're inputting the signal to your mixer through a line level input, like Nomad's inputs 7-10 for example, you are using the mic pre any way. Every XLR input I've used on a location sound mixer just introduces a pad for line level signals. That essentially makes your incoming line level signal mic level.

...

    

In my experience, this is simply not the case.  Although many modern designs may use some of the same components, they alter the circuit characteristics via a negative feedback loop to optimize for line level signals as opposed to mic level.  This is completely different than just padding down an input to mic level.

[mulluysavage]

Based on specs solely looking at the Rx line level is king - the reality of what is down stream determines how you slice it, and in the mix it would be very hard to tell the difference. +5 line on the 788; -25 to -20 mic on the 633 inputs 1-3; inputs 4-6 on 633 +5 and max menu gain on 633.

What ever works for you.

Can you explain further why you use mic level on inputs 1-3 on the 633? I use line, which does work for me, but I'd like to understand better. Does your principle also apply to the 664?