Topic: CAFS straight into M10 (mic in) -- overloaded recording. New: 2nd try was great

[tbger]

(originally "CAFS straight into M10 (mic in) -- overloaded recording. Help me learn my lesson")

The show was quite boomy in bass that I could feel my trousers moving.  I thought the extreme highs and the low bass were too loud where I was standing (right where the sound desk was), my guess is that since it was at a park and in front of more than 15,000 people, the sound had to be loud enough so that those standing away from the stage could hear and feel everything.

I was running CAFS straight into PCM-M10's mic in, with recording level set at 7.

I've taped a lot of shows using CA14 > CA-9100 > PCM-M10's LINE-IN, with very nice results.  Thought I'd give the CAFS a try, without the preamp, but oh the remorse ...

The single was hot at the recording, and every time there's a bass punch, it overloads.  You know it when you can't hear clapping between songs clear enough, and you kind of hear only the loudest claps which 'depress' the rest of sounds ?  ... Sorry my description is bad but I hope you get the idea. 

What could have been wrong with my setup ?  Is it the CAFS not being able to handle such strong bass ?  Or do they need a battery box to do that ?  Is it the recording level, or the fact I didn't use an external preamp ?

I haven't taped for more than a year and honestly forgot to watch my levels.  In post (sound editing programs) it looks like obvious overloading, which might imply I should have lowered the recording level.  Would that really help ?  In my experience when a mic can't handle bass it will overload no matter what level you record it at.


Thanks for any help

[yousef]

SSIA...

I know you occasionally see opinions to the opposite round here but I don't touch the 'mic-in' on any recorder unless I'm absolutely desperate for some extra gain that can't be provided from elsewhere.

Battery box/preamp into line-in and you can't go far wrong.

Edit to add: also, 7 sounds a bit on the high side to me - maybe that played a role too...

[Datfly]

I just did a LINE IN with the M10 recorder dial on 8 with no problems after Todd R. made a comment
about no real ill effects from going past "Unity Gain" 3 to 5ish on the M10.

[tbger]

By the way, I don't have the M10 around, but as far as I remember the recording level knob isn't functional when going LINE IN.

[tbger]

SSIA...

I know you occasionally see opinions to the opposite round here but I don't touch the 'mic-in' on any recorder unless I'm absolutely desperate for some extra gain that can't be provided from elsewhere.

Battery box/preamp into line-in and you can't go far wrong.

Edit to add: also, 7 sounds a bit on the high side to me - maybe that played a role too...

Thanks.

I'll try to see what I should have used in this case, a preamp or a battery box.  I guess I don't know enough to figure this out myself.

[vanark]

By the way, I don't have the M10 around, but as far as I remember the recording level knob isn't functional when going LINE IN.

Not sure where you got that... The recording level knob is functional when using line in.

[tbger]

I think I read it somewhere on the "Sony PCM-M10 (Part x)" a few years back.  Anyway that's great to know, thanks 

[TimSmith]

I think the problem most likely was in the absence of bbox or preamp. Its not easy to overload m10's mic input. It may happen on levels below 2, but not on 7.

Edit: well, if you did not watch your levels, it may be just clipping.

The single was hot at the recording, and every time there's a bass punch, it overloads.  You know it when you can't hear clapping between songs clear enough, and you kind of hear only the loudest claps which 'depress' the rest of sounds ?  ... Sorry my description is bad but I hope you get the idea. 

Sounds like hard limiting = clipping to me.

[tbger]

Hey Tim,

Thanks for your input.

Its not easy to overload m10's mic input. It may happen on levels below 2, but not on 7.

First of all I'd thought clipping and overloading describe the same thing.  Isn't it so ?
My intuition about this was:  the higher the recording level, the more chances you overload the recorder.  I guess I'm wrong ?

[taper666]

I think I read it somewhere on the "Sony PCM-M10 (Part x)" a few years back.  Anyway that's great to know, thanks 

the recording level knob is functional well when going LINE IN but changing the MIC SENS knob doesn't change anything when going LINE IN - I suppose that's what you read and was in your mind. I've had lots of distortion when going mic in at a very loud concert at level 4 (!!!) and using a battery box (PIP switched off in that case). That was back then when I learned my lessons - never went mic in again 

[tbger]

^^^ thanks a lot for your input, taper666.  That's surprising to hear ... lesson learnt here as well now ! 

Also thank you for the clarification on the level knob and sensitivity switch.  I was confusing the two probably.

[TimSmith]

@simplemind:

Taper666 is right. The general rule is to use line-in instead of mic-in when you can and *always* use bbox or preamp to provide enough (9v) power to the mics. Use 24 bit and dont worry that the levels will be too low. You can boost them in post. When I'm taping my levels are usually bouncing between -20 and -12db.

Clipping occurs when the wave goes above 0db and gets cutted. The overload (=brickwalling) may happen even if the levels are below 0db. It depends on how loud the signal actually is. The louder music is - the lower level setting you use to keep the levels below 0db, and at some point the overload begins. Line in can take hotter signal than mic-in - thats why you should prefer it for loud shows. It is useful to make some tests with your home stereo or at a cheap local show and see how it goes.

Anyway my experience tells me that micin overload cant happen at level 7. I've recently taped several loud shows at setting 5 mic in with the levels peaking at -12db.

And always set the mic sensitivity switch to low, unless you tape something extremely quiet.

That's as much as I can tell.

[tbger]

Hello Tim,

Let me know if I got you clearly:  if overload didn't happen for you at rec. level 5, it will necessarily not happen at 7 ?   I mean, does chances for overloaded-signal lower as the rec. level goes higher ?

Thank you again

[earmonger]

Quick summary: For a loud show, send the mics through a battery box or preamp into line-in.  A battery box is all you need for loud amplified music.

Here's why:

A Mic-in jack does two things. It provides power (Plug-in power on the PCM-M10, a few volts) to the mic and it sends the signal through a built-in preamp.

The Line-in Jack, meanwhile, is for a signal from something amplified or powered, so it provides neither power or preamp.

Going through Mic-in, overload can happen at two different spots in the recording chain:

1) It can happen at the mics themselves--mics can only handle a certain sound pressure level (volume), particularly in the bass.

2) It can happen in the preamp, and again megabass is the quickest to overload it. If you had the mics at Hi Sensitivity, the preamp is boosted higher and overloads faster. 

To help prevent (1) you provide more power to the mics, either through a battery box (which is generally all you need at loud shows) or a preamp (which, turned to zero gain, is essentially a battery box); more power helps them handle higher volumes.

(2) To skip the built-in preamp in the unit, you go through line-in with a better preamp or a powered signal (via battery box) from the mics. For loud shows, a battery box into Line-in works well because it's loud enough--you don't need amplification from the preamp.

[tbger]

^^^  That's very helpful, thanks a lot.