Topic: PCM-M10 microphone upgrade options

[diehlr]

I suppose technically I am upgrading from a Sony Minidisc setup circa 1998 with CoreSound binaural mics, although I sold / gave away the setup a few years back from non-use. The main reason I gave away the setup is because of the inconvenience factor of having a rig full of gear strapped to my body and not being able to enjoy myself while taping shows.

I recently purchased a Sony PCM-M10 due to it appearing to be a pocket sized solution where I could more-or-less set it and forget it. I am not aiming to obtain a prestine recording of shows I attend, but I have noticed a distinct shortcoming in my rig, which is that many of the shows I attend appear to overload the internal mics of the PCM-M10 and produce a fairly pronounced distortion in the recording. Nearly all of the shows I record require me to set the gain to Low at around 2.0 on the dial. This results in the meters displaying levels of around -6 or so typical maximum values, but when listening to the recordings, I am observing significant levels of distortion.

So, my question is, does anyone know of some relatively low-maintenance external microphones that could be coupled with the PCM-M10 that doesn't require phantom power? I am fine with omni-directional mics because I generally tend to plop the recorder down and let it do its job. I don't mind some crowd noise as a result of omni mics (the previous Core Sound mics I used to use were fabulous, but the cardiod design made them a little but too directionally sensitive).

My primary goal is to decrease distortion due to loud SPL but also maximize the practicality factor in making the entire setup relatively compact and friendly to someone who just wants to set down a recorder and let it do its thing. As far as budget goes, anything under $500 for some mics that will result in a good sounding, yet ergonomically friendly setup is greatly appreciated!

Speaking of which, would it be worth just upgrading to the Sony PCM-D50? How are the mics in this thing compared to the M10 in terms of dealing with loud concert venues?

[earmonger]

To beat the overload, send your mics through a battery module into Line-in.  It will end the distortion problem for anything but the most brutally bass-heavy shows (which could overload your mics even before the signal reaches the battery box). You don't need a preamp, or bass roll-off, or anything fancier than a battery module.

The battery module is not as big as a phantom power supply. It can be as compact as the first three gizmos on this page, each slightly bigger than a 9V battery, smaller than a cigarette pack.

http://www.soundprofessionals.com/cgi-bin/gold/category/310/mics

And then you can get as much mic as you want to pay for--anything with a 1/8" stereo miniplug. Church Audio gets a lot of props here (search the Yard Sale for his deals), and guysonic's SonicStudios DSM, which I have never been able to afford. You  can even get better sound than the PCM-10 built-ins from little clip-ons like the $59 Sound Professionals BMC-2. 

 http://www.soundprofessionals.com/cgi-bin/gold/item/SP-BMC-2

I have a beef with SoundPros at the moment over their BMC-12, which have no bass response despite being shown with a frequency response of 20-20000 Hz. It's in a nice sweet price range of around $99 but don't be tempted--it's a speech mic, not a music mic.  I contacted them about the wrong specs, but they remain unchanged.

Whatever you get, make sure it has a 30-day guarantee so you can try it and see how you like it.

My portable rig is little clip-on mics, PCM-10, battery module and a LowePro Ridge 30 camera pouch, which conveniently has a separate pocket that fits the battery module and a place in its flap for the PCM-10's little flat remote. 

[su6oxone]

Your best options are probably the Church Audio CA-11 w/cardioid and omni caps and the Sound Pro AT853 series w/omni, subcard, hypercard, and cardioid caps (maybe even shotgun too).  The AT853 will need to get the 4.7k mod (they can do it if you buy new from them, or Chris Church can do it also for a reasonable fee) to handle loud shows.  Either way, you will need either a battery box or a preamp to power them, probably the Church Audio 9100 preamp is your best bet as it can power your mics and give it nice clean gain too when needed. 

[Flashmd]

I have experienced similar distortion issues during several bass heavy concerts, in which I had intentionally used one of the Low Frequency Filter settings to minimize or balance out the spectrum for a tasteful sound on playback.

However doing so, I had noted distortion during the realtime recording when using closed headphones to monitor. A quick check of the meters indicated safe levels.... but not the whole story.

Apparently the gain structure in the M10 is such that, much like a mix board error abusing the EQ, overloaded due to the LOW filter affecting the meter readings as well.

In other words, the gain stage before the filter was overloading, because I depended on the meters to stay out of the danger zone. The meters simply did not see the Lows to so call pin them!

With some quick thinking, I decided to lower my recording gain despite my meter readings, then everything sounded better!

So my question to you is, whether or not, your LOW EQ Filter was on at the time committing a crime under your nose. Hope this helps solve another mystery...Happy Recording:)

[diehlr]

I always leave the bass rolloff disabled in the PCM-M10 menus. Darn, I was hoping I would be able to get away with avoiding some kind of external power supply brick. I really like the portability and low maintenance factor of the integrated mics, but the distortion in loud recordings is really getting on my nerves. I might give a while lowering the levels more just in case it is clipping even though the meters indicate otherwise, but I am kind of doubting it will make any difference.

Do any other handheld recorders have better integrated mics?

[kleiner Rainer]

I always leave the bass rolloff disabled in the PCM-M10 menus. Darn, I was hoping I would be able to get away with avoiding some kind of external power supply brick. I really like the portability and low maintenance factor of the integrated mics, but the distortion in loud recordings is really getting on my nerves. I might give a while lowering the levels more just in case it is clipping even though the meters indicate otherwise, but I am kind of doubting it will make any difference.

Do any other handheld recorders have better integrated mics?

The M10 internal mics are specified with a maximum SPL of 123dB (A-weighted). This is just below the pain threshold. If the mics distort (even with low mic gain settings), I would be concerned about my hearing. Look here:

http://www.gcaudio.com/resources/howtos/loudness.html

I would consider using hearing protection, if the mics are really clipping 

BTW I record steam trains, and the only ocurrence of mic clipping was when a safety valve set to 18 bar blew off 5-10m from my mics...

I would try setting mic sensitivity to "Low" for loud shows and then reduce the gain.
It worked for me when recording church bells forming a 50 bell carillon at a distance of abt. 3m
 
http://upload.wikimedia.org/wikipedia/commons/c/ce/WestertorenAmsterdam.jpg
 
BTW the largest bell in this carillon weighs 7.5 tons. Thats real heavy metal 

EDIT: http://www.youtube.com/watch?v=Q3eJ5FZnR1g&feature=related   shows where I recorded: the M10 was placed on one of the upper steps of the stair.

Greetings,

Rainer

[Church-Audio]

I always leave the bass rolloff disabled in the PCM-M10 menus. Darn, I was hoping I would be able to get away with avoiding some kind of external power supply brick. I really like the portability and low maintenance factor of the integrated mics, but the distortion in loud recordings is really getting on my nerves. I might give a while lowering the levels more just in case it is clipping even though the meters indicate otherwise, but I am kind of doubting it will make any difference.

Do any other handheld recorders have better integrated mics?

The M10 internal mics are specified with a maximum SPL of 123dB (A-weighted). This is just below the pain threshold. If the mics distort (even with low mic gain settings), I would be concerned about my hearing. Look here:

http://www.gcaudio.com/resources/howtos/loudness.html

I would consider using hearing protection, if the mics are really clipping 

BTW I record steam trains, and the only ocurrence of mic clipping was when a safety valve set to 18 bar blew off 5-10m from my mics...

I would try setting mic sensitivity to "Low" for loud shows and then reduce the gain.
It worked for me when recording church bells forming a 50 bell carillon at a distance of abt. 3m
 
http://upload.wikimedia.org/wikipedia/commons/c/ce/WestertorenAmsterdam.jpg
 
BTW the largest bell in this carillon weighs 7.5 tons. Thats real heavy metal 

EDIT: http://www.youtube.com/watch?v=Q3eJ5FZnR1g&feature=related   shows where I recorded: the M10 was placed on one of the upper steps of the stair.

Greetings,

Rainer

Lots of companies use high spl distortion specs.. They can be misleading.. Just because they say 123 db SPL does not mean its at low frequency. Low frequency distortion is never specified. So they might distort at lower levels then 123 db. And using bass roll off or high pass filter WILL NOT fix mic distortion only mask it. The distortion is happening at the mic capsule no bass roll off can fix that.

[kleiner Rainer]

Lots of companies use high spl distortion specs.. They can be misleading.. Just because they say 123 db SPL does not mean its at low frequency. Low frequency distortion is never specified. So they might distort at lower levels then 123 db. And using bass roll off or high pass filter WILL NOT fix mic distortion only mask it. The distortion is happening at the mic capsule no bass roll off can fix that.

From what I understand, omni condenser mics as used in the PCM-M10 are pressure transducers whose membrane elongation is frequency independent for a given sound pressure (see this excellent ebook written by the former Neumann chief engineer: http://www.neumann.com/download.php?download=docu0002.PDF , especially page 32). The primary source of distortion is the nonlinearity of the capacitance change at high SPL (page 40).
This leads me to believe that maximum SPL for omnis is frequency independent.

The behaviour of the FET amplifier in electret mics with two-wire interface is also a source of distortion: the voltage-to-current conversion has a quadratic component that gets worse with higher input voltage - this is also distortion, and it is also frequency-independent. Another source of distortion is insufficient drain voltage (this is the cause for using "battery boxes" instead of PIP - plug-in power). This type of distortion is also frequency-independent.

Googling found another interesting article with measurements of high-SPL-distortion in microphones at lower frequencies:

http://www.fesb.hr/~mateljan/arta/AppNotes/AP5_MikroMeasChamber-Rev03Eng.pdf     Page 15

Do you have a reference for the frequency dependence of distortion at high SPL levels? I am interested!

Greetings,

Rainer

[Church-Audio]

Lots of companies use high spl distortion specs.. They can be misleading.. Just because they say 123 db SPL does not mean its at low frequency. Low frequency distortion is never specified. So they might distort at lower levels then 123 db. And using bass roll off or high pass filter WILL NOT fix mic distortion only mask it. The distortion is happening at the mic capsule no bass roll off can fix that.

From what I understand, omni condenser mics as used in the PCM-M10 are pressure transducers whose membrane elongation is frequency independent for a given sound pressure (see this excellent ebook written by the former Neumann chief engineer: http://www.neumann.com/download.php?download=docu0002.PDF , especially page 32). The primary source of distortion is the nonlinearity of the capacitance change at high SPL (page 40).
This leads me to believe that maximum SPL for omnis is frequency independent.

The behaviour of the FET amplifier in electret mics with two-wire interface is also a source of distortion: the voltage-to-current conversion has a quadratic component that gets worse with higher input voltage - this is also distortion, and it is also frequency-independent. Another source of distortion is insufficient drain voltage (this is the cause for using "battery boxes" instead of PIP - plug-in power). This type of distortion is also frequency-independent.

Googling found another interesting article with measurements of high-SPL-distortion in microphones at lower frequencies:

http://www.fesb.hr/~mateljan/arta/AppNotes/AP5_MikroMeasChamber-Rev03Eng.pdf     Page 15

Do you have a reference for the frequency dependence of distortion at high SPL levels? I am interested!

Greetings,

Rainer

Actually thats not entirely true. Since frequency's below 200hz are non directional omni mics tend to be more efficient at picking up low frequency then say a cardioid mic would. So they tend to be overloaded first in the low frequency area. Most manufactures of mics don't tend to measure the effects of low frequency distortion. Because its difficult to do. 

For the most part electret capsules we use for live recording have a much large backplate to diaphragm space then studio condenser mics have. Thus problems with diaphragms hitting the back plate are not really an issue with small electret.. Its more an issue of voltage swing and the inability of the poor little fet inside the capsule to deal with it. Thus designs like my design have a much lower level of distortion. But it comes at a cost of sacrificing sensitivity this is not an issue for concert recording because high sensitivity is not required.

[Church-Audio]

I always leave the bass rolloff disabled in the PCM-M10 menus. Darn, I was hoping I would be able to get away with avoiding some kind of external power supply brick. I really like the portability and low maintenance factor of the integrated mics, but the distortion in loud recordings is really getting on my nerves. I might give a while lowering the levels more just in case it is clipping even though the meters indicate otherwise, but I am kind of doubting it will make any difference.

Do any other handheld recorders have better integrated mics?

The M10 internal mics are specified with a maximum SPL of 123dB (A-weighted). This is just below the pain threshold. If the mics distort (even with low mic gain settings), I would be concerned about my hearing. Look here:

http://www.gcaudio.com/resources/howtos/loudness.html

I would consider using hearing protection, if the mics are really clipping 

BTW I record steam trains, and the only ocurrence of mic clipping was when a safety valve set to 18 bar blew off 5-10m from my mics...

I would try setting mic sensitivity to "Low" for loud shows and then reduce the gain.
It worked for me when recording church bells forming a 50 bell carillon at a distance of abt. 3m
 
http://upload.wikimedia.org/wikipedia/commons/c/ce/WestertorenAmsterdam.jpg
 
BTW the largest bell in this carillon weighs 7.5 tons. Thats real heavy metal 

EDIT: http://www.youtube.com/watch?v=Q3eJ5FZnR1g&feature=related   shows where I recorded: the M10 was placed on one of the upper steps of the stair.

Greetings,

Rainer

Your first line in the spec of the M10 says it all A weighted distortion measurement. Means that low frequency distortion can be happing at a much lower level then 123db Thus proving my point about the fact that most of the Max SPL statements do not incorporate low frequency into the equation.. Why? The task of finding a low frequency LOW distortion source is almost impossible. You can use an actuator but thats not the same as free field unless you have correction data.. The next possible way would be a a plane tube measurement.. But you would need one hell of a large tube to measure down that low


Although its just below the pain threshold at 123 db at 1k I assure you at 100hz its much below the pain threshold.. I am also pretty sure the pain threshold is higher around 135db.

[kleiner Rainer]

Your first line in the spec of the M10 says it all A weighted distortion measurement. Means that low frequency distortion can be happing at a much lower level then 123db Thus proving my point about the fact that most of the Max SPL statements do not incorporate low frequency into the equation.. Why? The task of finding a low frequency LOW distortion source is almost impossible. You can use an actuator but thats not the same as free field unless you have correction data.. The next possible way would be a a plane tube measurement.. But you would need one hell of a large tube to measure down that low


Although its just below the pain threshold at 123 db at 1k I assure you at 100hz its much below the pain threshold.. I am also pretty sure the pain threshold is higher around 135db.

Wrong. I stated the SPL in the correct form. The SPL is measured A-weighted and at 1kHz, because it is in the standards (and the instruments for measuring SPL have an "A" weighting filter). So, if you use an "A" weighted instrument to measure low-frequency SPL, it will show too low levels: at 100Hz it is abt. 20dB down from 1kHz, at 20Hz 50dB! So in fact, if you measure an SPL of 100dB(A) at 100Hz, it is in fact 20dB higher, and an omni mic will show it, because it does not care about weighting.

The published pain threshold varies between 120 and 140dB (A). It is not a fixed value, but depends on the individual. In an old reference book for audio engineers, "Webers, Tonstudiotechnik", I found 120dB, and OSHA defines it at 140dB. The 120 dB seem to come from the classic Fletcher-Munson measurements decades ago.

BTW in my other post I did not write about the diaphragm touching the backplate, but about the fact that big elongations of the diaphragm get nonlinear - that is something different. Your mics for high SPL recording use lower resistor values to lower the output voltage, but at the price of a higher equivalent noise SPL, right? Been there, done that... and I also experimented with current mirrors to get rid of the drain voltage variation of the FET - works great!

But I agree - measuring mics is a minefield, if you want to do it the correct way.

Thanks for an interesting discussion - and I hope the less technical inclined are not bored to death.

Greetings,

Rainer

[Church-Audio]

Your first line in the spec of the M10 says it all A weighted distortion measurement. Means that low frequency distortion can be happing at a much lower level then 123db Thus proving my point about the fact that most of the Max SPL statements do not incorporate low frequency into the equation.. Why? The task of finding a low frequency LOW distortion source is almost impossible. You can use an actuator but thats not the same as free field unless you have correction data.. The next possible way would be a a plane tube measurement.. But you would need one hell of a large tube to measure down that low


Although its just below the pain threshold at 123 db at 1k I assure you at 100hz its much below the pain threshold.. I am also pretty sure the pain threshold is higher around 135db.

Wrong. I stated the SPL in the correct form. The SPL is measured A-weighted and at 1kHz, because it is in the standards (and the instruments for measuring SPL have an "A" weighting filter). So, if you use an "A" weighted instrument to measure low-frequency SPL, it will show too low levels: at 100Hz it is abt. 20dB down from 1kHz, at 20Hz 50dB! So in fact, if you measure an SPL of 100dB(A) at 100Hz, it is in fact 20dB higher, and an omni mic will show it, because it does not care about weighting.

The published pain threshold varies between 120 and 140dB (A). It is not a fixed value, but depends on the individual. In an old reference book for audio engineers, "Webers, Tonstudiotechnik", I found 120dB, and OSHA defines it at 140dB. The 120 dB seem to come from the classic Fletcher-Munson measurements decades ago.

BTW in my other post I did not write about the diaphragm touching the backplate, but about the fact that big elongations of the diaphragm get nonlinear - that is something different. Your mics for high SPL recording use lower resistor values to lower the output voltage, but at the price of a higher equivalent noise SPL, right? Been there, done that... and I also experimented with current mirrors to get rid of the drain voltage variation of the FET - works great!

But I agree - measuring mics is a minefield, if you want to do it the correct way.

Thanks for an interesting discussion - and I hope the less technical inclined are not bored to death.

Greetings,

Rainer

Um no I am not wrong. Actually measuring distortion via A weighting does not show low frequency distortion at all. You can have a mic that measures quite well at 1k and quite poorly at 100hz.. Actually.. Bored to death hopefully not I think there are many people on here that fine such discussions interesting And yes the industry standard is at 1k I think it should be measured at at least 4 different points in the 1/3 octave spectrum. BTW thats not true that all measurements for spl are A weighted.. And that they are all set up that way.. Lots of meters allow for None or MANY different weighting curves.

[kleiner Rainer]

I was not talking about measuring the DISTORTION A-weighted, but the SOUND LEVEL! Measuring distortion in mics is another can of worms.

Greetings,

Rainer

[Church-Audio]

I was not talking about measuring the DISTORTION A-weighted, but the SOUND LEVEL! Measuring distortion in mics is another can of worms.

Greetings,

Rainer

I do know the difference..  They are stating Max spl at 123 dbA I am not sure what that means with out a distortion in a percentage at that level But anyway ALL I am saying is simple. When you say A wheighted you dont take into consideration low frequencey so at 123dbA you can have much more distortion if you measure at say 100hz 123 db source.

So if your source is 123 db at 1k thats one percentage of distortion at that Acoustic level

IF you measure at 123 db at 100hz thats another percentage of distortion...

You can have a mic that has a spec of 1% at 123 dbA at 1k and then do an unweighted measurement at 100hz at 123 db and get quite different distortion percentages..


So its misleading.. not that you are trying to mislead anyone... BUT the spec it self is misleading.

The simple truth of the matter is I have 1000's of customers that are happy that my mics dont overload.. Lots of companies that make mics that eventually get sent to me for modification. That is the bottom line. If the mics did not overload nobody would send them too me.. And they all have "super high" Max spl specifications based on 1k
Most of them cant come close to handling a real live show with out overload.

[guysonic]

I always leave the bass rolloff disabled in the PCM-M10 menus. Darn, I was hoping I would be able to get away with avoiding some kind of external power supply brick. I really like the portability and low maintenance factor of the integrated mics, but the distortion in loud recordings is really getting on my nerves. I might give a while lowering the levels more just in case it is clipping even though the meters indicate otherwise, but I am kind of doubting it will make any difference.

Do any other handheld recorders have better integrated mics?

My own custom made stereo-surround DSM mics are directly powered to fullest performance by M10's mic power, so no external anything needed for having a no-compromise 2-piece outfit as described here: http://taperssection.com/index.php?topic=83254.0

It does seem most of you are not aware to never place this and most portables in HIGH mic input sensitivity that gives plenty of gain, but lots of overload distortion faced with amplified sources.  Use only the LOW setting.   M10 mic input can handle without distortion +4 dBu which is more than a lot of decks can handle using thier LINE input!

Below are suggestions on getting both external and the M10 internal mics working for cleanly recording most anything at moderate to very loud volume.

------------------
TIPS: (For highest quality recording purposes)
 
Use M10 ONLY set in 24 bit recording mode.  Sample rate is your choice, but suggest using 44.1K sample rate if wanting best CD compatible editing options.
 
Use M10 ONLY with MIC INPUT sensitivity switch set in "LOW" taping over this switch to not be moved.  "HIGH" setting is way too much 20 dB boosted first stage gain giving inferior audio quality.  Even with very low VU levels, LOW setting gives cleaner more defined 24bit depth audio best boosted in post edit, NOT by using deck in HIGH setting.
 
Allow for having best headroom dynamics with NOT pushing recording VU levels.   Wise to ONLY push REC levels of master recording to -12 dB PEAK VU (not average, but maximum peak reading) so recording has best chance of never clipping even if much louder unexpected sound is encountered.
 
Use M10 in full manual (not AUTO, Limiter) record level control mode setting, suggest also taping over this switch so it does not move. 
 
Wise tact is to always engage HOLD feature so touching buttons do not accidentally stop recording until you're ready to stop the session. 
 
Do all editing in 24 bit mode, adjusting loudness and other changes desired.  Then as last software edit step convert copy of file to 16 bit if later doing CD storing this copy of file for disc burning purposes.
 
See taperssection.com M10 comments/tech data GuySonic posted at: http://taperssection.com/index.php?topic=130924.0;all 
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