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Gear / Technical Help => Ask The Tapers => Topic started by: shpy on February 22, 2020, 06:17:31 AM

Title: brickwalling using XLR conections. Help!
Post by: shpy on February 22, 2020, 06:17:31 AM
Hy everybody. I need some answers.
I had a problem before (brickwaling) using  SP-CMC-2-XLR https://www.soundprofessionals.com/cgi-bin/gold/item/SP-CMC-2-XLR directly to OLYMPUS LS-100 recorder. So tapers suggested to buy line-in  -20 db pad. SO i did. Brought  Shure A15AS https://www.shure.com/en-US/products/accessories/a15as.
Yesterday i had event and today im listening record and still in some parts i got distortion.

Settings used:
XLR input with (low sensitivity)
Mic input gain wheel was around 4 from 10. using -25dB PAD
Recording level around -12 db

https://drive.google.com/file/d/1jG6zQTmBi3euiePRZGvxN4W2LyNFtfP5/view

Mics where set in the end of club. Its small club.

Best part is that my colleague recorded same concert with https://www.soundprofessionals.com/cgi-bin/gold/item/SP-CMC-4U mics using battery box with bass rolloff connected directly to camera and sound is way better.
https://youtu.be/es6FdDxfEq8

P.S. Don't afraid of music style.
Title: Re: brickwalling using XLR conections. Help!
Post by: kuba e on February 22, 2020, 01:47:20 PM
Shpy, you don't need 4.7k mod when the mics are connected via xlr.  AT831 are designed to be powered via xlr. Mod 4.7k is intended only for mics that are reterminated to 1/8'' (two wires connection instead three wires). Look on your recording in some audio program e.g. Audacity. Are the highest peaks reaching 0db?

Cheesecadet, I don't know how pads are affecting audio signal and noise floor. But I wonder.
Title: Re: brickwalling using XLR conections. Help!
Post by: hubbachild on February 22, 2020, 02:30:59 PM
Is the phantom power on your deck set to 24v or 48v?  You want to be at 48v. You can use 24v but you won't be able to handle as much SPL as at 48v. Page 84 of the manual, mic power menu. You should not need to use the -20db pad.
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on February 22, 2020, 03:08:41 PM
Yes i use 48v. Chris from sound profesionals said  same, that my recorder provide low sensivity setting on xlr so  it should be ok.. but its not.. even with -20 pad.. so what the hell...
Title: Re: brickwalling using XLR conections. Help!
Post by: kuba e on February 22, 2020, 03:33:09 PM
You cannot exceed 0db.  Send us some short sample where the distortion occurs. Did you switch on the low sensitivity in the settings of your recorder?
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on February 23, 2020, 03:54:01 AM
Chris from Sound professional said I need more Attenuation.  Other members said that  -20db is optimal, lower can be bad for sound. Quality pad i found is max -30dB https://www.audio-technica.com/cms/electronics/a05620466ab0ce16/index.html
But who can say that its will be enough :(

I come to Conclusions, that XLR is bad decision to use for LOUD source.
Title: Re: brickwalling using XLR conections. Help!
Post by: kuba e on February 23, 2020, 05:47:27 AM
There is no clipping in the sample. You have headroom of 8.8 db. The pad -20 db is ideal. And you still have some reserve for louder music. You can set recorder's gain wheel to 1 instead 3.

I don't hear a distortion in the sample. Maybe someone more sensitive can hear it. I do not think that the distortion is originating in the microphone or recorder. Maybe the distortion is in the music itself. ;D

Xlr connection is the best. We are using 1/8'' connection only because smaller size and less demands on recorder.

P.S.: If you want more stereo, try a greater angle or spacing between microphones.
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on February 23, 2020, 06:21:46 AM
There is no clipping in the sample. You have headroom of 8.8 db. The pad -20 db is ideal. And you still have some reserve for louder music. You can set recorder's gain wheel to 1 instead 3.

I don't hear a distortion in the sample. Maybe someone more sensitive can hear it. I do not think that the distortion is originating in the microphone or recorder. Maybe the distortion is in the music itself. ;D

Xlr connection is the best. We are using 1/8'' connection only because smaller size and less demands on recorder.

P.S.: If you want more stereo, try a greater angle or spacing between microphones.

You dont hear distortion on drums? :O Especially Around 1:53
Title: Re: brickwalling using XLR conections. Help!
Post by: Walstib62 on February 23, 2020, 11:18:13 AM
The recording is very bass heavy. You could try to engage the bass roll-off on the recorder. You can then boost the bass back up in post if you want to.
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on February 23, 2020, 11:51:59 AM
The recording is very bass heavy. You could try to engage the bass roll-off on the recorder. You can then boost the bass back up in post if you want to.

Didint try that..  I have low cut filter 300 and 100 Hz
Title: Re: brickwalling using XLR conections. Help!
Post by: EmRR on February 23, 2020, 12:16:18 PM
I don't hear distortion either.  Many times the PA itself will be clipping at shows like this. 

Headroom in the recorder looks fine.  The mics don't appear distortable according to the spec. 

You may be surprised how much level drops if you take bass out, that's where most energy is.  I'd start with 100, 300 would be pretty heavy handed. 
Title: Re: brickwalling using XLR conections. Help!
Post by: nulldogmas on February 23, 2020, 12:45:17 PM
I don't hear distortion, either, especially not when listening on my headphones with better bass response. You might try just reducing the low end with some EQ, and see if it sounds better to you.
Title: Re: brickwalling using XLR conections. Help!
Post by: Humbug on February 23, 2020, 06:05:46 PM
Hi,

I tried some mild EQ, using a recent EQ I'd used for another rock show (not as heavy as this):

https://www.dropbox.com/s/spio22uvhgajbh7/VOC_190820-0081_MOD%20Humbug%20EQ.wav?dl=0

Attached is a rough idea of what I used, though I used +12dB
Title: Re: brickwalling using XLR conections. Help!
Post by: Humbug on February 23, 2020, 06:08:10 PM
As I've stated on your other thread, CMC2's are absolutely fine for rock/metal, though you need to play with the settings, and/or get used to EQ.
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on February 24, 2020, 03:22:23 AM
Hi,

I tried some mild EQ, using a recent EQ I'd used for another rock show (not as heavy as this):

https://www.dropbox.com/s/spio22uvhgajbh7/VOC_190820-0081_MOD%20Humbug%20EQ.wav?dl=0

Attached is a rough idea of what I used, though I used +12dB

Thanks you all. So Ok i understood that problem is to heavy bass.. I use EQ in post production but usually leave bass or even add some. In this case its to much :)
Title: Re: brickwalling using XLR conections. Help!
Post by: kuba e on February 24, 2020, 07:04:15 AM
Attached is a rough idea of what I used, though I used +12dB

Clipping and similar kind of distortions can occur at three different places - in microphone electronics, in recorder electronics or during post processing.

Maybe your problem has arised during post-processing. Your original sample track has headroom 8.8 dB. If you amplify this track by +12dB and you don't use limiter or compressor, you will cause clipping. Amplification above 8.8 dB cuts the highest peaks of sound waveform. You have to use limiter (or compressor). To put it simply, the limiter rounds off the cut off peaks and then it doesn't sound distracting.

Title: Re: brickwalling using XLR conections. Help!
Post by: morst on February 24, 2020, 12:31:15 PM
You dont hear distortion on drums? :O Especially Around 1:53
Nope. Floor tom hits are clean. Try a mastering limiter, it's already pretty compressed-sounding.


The distortion I hear is the guitar tones, but they are typical overdriven metal sounding. The growling vocals are similarly distorted from the source, where it sounds like the vocalist might be "cupping" the mic inside the palm of the hand. The guitars are louder than the vocals, but that's just because you were probably close to the stage, or the guitars were so loud that there was no escaping them.
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on February 24, 2020, 02:51:40 PM
Full show: https://youtu.be/rxTMGkyz5AQ. But i posted this video before posting problem here. I haven't reduced bass. Next time :)
Title: Re: brickwalling using XLR conections. Help!
Post by: beatkilla on February 24, 2020, 05:15:50 PM
Full show: https://youtu.be/rxTMGkyz5AQ. But i posted this video before posting problem here. I haven't reduced bass. Next time :)


Sounds fine over here.

What camera are you using to film with?
Title: Re: brickwalling using XLR conections. Help!
Post by: opsopcopolis on February 24, 2020, 05:44:33 PM
I hear some distortion on my little apple headphones, but not on any of my bigger gear. Leads me to believe that you're probably listening on speakers that can't reproduce the sub freqs that are extremely prevalent in that source. I agree with the others that a low shelf of some sort (mess around with q, and freq) would probably help.
Generalizations ahead, so proceed with caution: Unless you're EQ-ing to listen on a system with actual subs and want to be pounded to death, I'd say it's pretty rare to need to amplify anything below 100 and definitely anything below 60
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on February 25, 2020, 01:27:53 AM
Full show: https://youtu.be/rxTMGkyz5AQ. But i posted this video before posting problem here. I haven't reduced bass. Next time :)


Sounds fine over here.

What camera are you using to film with?

Fuji X-T3 :)
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on February 25, 2020, 01:29:09 AM
I hear some distortion on my little apple headphones, but not on any of my bigger gear. Leads me to believe that you're probably listening on speakers that can't reproduce the sub freqs that are extremely prevalent in that source. I agree with the others that a low shelf of some sort (mess around with q, and freq) would probably help.
Generalizations ahead, so proceed with caution: Unless you're EQ-ing to listen on a system with actual subs and want to be pounded to death, I'd say it's pretty rare to need to amplify anything below 100 and definitely anything below 60

Im using Audio Technica ATH-M40x :)
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on March 11, 2020, 06:40:17 AM
Maybe now someone will hear, that sound is not right? Yesterday show WITH PAD -25dB. https://drive.google.com/open?id=1jG6zQTmBi3euiePRZGvxN4W2LyNFtfP5  I dont understand whats going on :((

Best part is that my colegue recorded same concert with https://www.soundprofessionals.com/cgi-bin/gold/item/SP-CMC-4U mics using batterybox with bass rolloff connected directly to camera and sound is way better.
https://youtu.be/es6FdDxfEq8
Title: Re: brickwalling using XLR conections. Help!
Post by: kuba e on March 11, 2020, 02:43:47 PM
Yes, there is a distortion. It is difficult to say where is the origin of this distortion. The waveform has a 16db headroom.

I don't own these mics. I looked at the web page you provided at the first post and there is written "Power Requirements- 48v phantom power with power converter adapter". I see that the mics are terminated to the classic xlr connectors. I am not sure that the phantom adapter is inside that connector. Did the manufacturer confirm that you can connect these mics directly to the phantom power 48 V? What exact chain of gear do you use?
Title: Re: brickwalling using XLR conections. Help!
Post by: morst on March 11, 2020, 04:46:57 PM
Yes, there is a distortion. It is difficult to say where is the origin of this distortion.
Just listened to the start of the video and the distortion sounds like it's the keyboards, or the recorded track, since they don't appear to have a keyboardist.
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on March 11, 2020, 04:55:48 PM
Yes, there is a distortion. It is difficult to say where is the origin of this distortion. The waveform has a 16db headroom.

I don't own these mics. I looked at the web page you provided at the first post and there is written "Power Requirements- 48v phantom power with power converter adapter". I see that the mics are terminated to the classic xlr connectors. I am not sure that the phantom adapter is inside that connector. Did the manufacturer confirm that you can connect these mics directly to the phantom power 48 V? What exact chain of gear do you use?

Price i paid for xlr modification was 100$ so i think adapter is inside.. i never asked but wrote to chris that i have problem. I think something with mics not right..
Title: Re: brickwalling using XLR conections. Help!
Post by: jerryfreak on March 11, 2020, 05:50:07 PM
PS. Event's sound man was a Girl and it was her second attempt or maybe more.. but we all felt she don't do her task well

how is that relevant? was she using her vagina instead of her ears to monitor the sound or something?
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on March 12, 2020, 06:02:44 AM
Yes, there is a distortion. It is difficult to say where is the origin of this distortion. The waveform has a 16db headroom.

I don't own these mics. I looked at the web page you provided at the first post and there is written "Power Requirements- 48v phantom power with power converter adapter". I see that the mics are terminated to the classic xlr connectors. I am not sure that the phantom adapter is inside that connector. Did the manufacturer confirm that you can connect these mics directly to the phantom power 48 V? What exact chain of gear do you use?

Price i paid for xlr modification was 100$ so i think adapter is inside.. i never asked but wrote to Chris that i have problem. I think something with mics not right..

Im still waiting answer form Chris about power converter. But if it turns out that there was no power converter inside then i speechless. To run these mics i should use chain:
mics-> -20dB pad -> converter ->recorder. Very Long stick out from recorder. NO portable at all and expensive.

I hope so that adapter inside.



Title: Re: brickwalling using XLR conections. Help!
Post by: kuba e on March 12, 2020, 06:37:31 AM
You are right Jerryfreak.

Shpy, the last thing that occurred to me. Make sure you have freshly charged batteries in the recorder. If possible, try another recorder to make sure there is a problem with the microphones. Maybe the girl would be kind and give you two inputs with phantom 48 V and a line output from her soundboard.
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on March 12, 2020, 08:03:46 AM
You are right Jerryfreak.

Shpy, the last thing that occurred to me. Make sure you have freshly charged batteries in the recorder. If possible, try another recorder to make sure there is a problem with the microphones. Maybe the girl would be kind and give you two inputs with phantom 48 V and a line output from her soundboard.

forget that girl. Its another event, new recording. Its not AA batteries https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcToKp7lPtq0DfFtqXuz-xjA4LKGYdKec5Riez8rkJr2DaOM5O5Ymg&s I have three original LI-50B batteries. Sad that i don't have another recorder :(
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on March 13, 2020, 10:17:27 AM
Chris said My mics with power converter inside. Last guest that my mics disort due to lack of rollbass-of. Deep Bass saunds could make distorsion. So i should use bass off pads.. but im afraid to imagin how ugly my setup should look. Rollbass off plus attenuator pad
Title: Re: brickwalling using XLR conections. Help!
Post by: kuba e on March 13, 2020, 08:18:43 PM
Bass roll off should help if your microphone's output is too hot. But the signal is -16db in the output of recorder's preamp. I think here is no problem. (Do not use preset bass roll off. It is better to reduce lows in post because you can reduce it precisely while listening.)

The distortion could occur:
-in the microphone when the maximum loudness is exceeded. We can exclude it because your microphone specification is "Maximum Input Sound Level- 151dB"
-in the microphone when it is not properly powered. You should check your phantom power settings in the recorder. You need 48 V according specification on the web page.
-in the recorder's preamp input. This can be assessed by someone who understands the technical data. Unfortunately, I don't know this. I guess there's no trouble here.
-in the recorder's preamp output.  We can exclude this because the recording sample is -16db.
-Also check if you have set any limiter or compressor in the recorder. Turn it all off.

Try to ask a sound guy from your club for help. Explain him your problem. He could find a way how to test your microphones/recorder.
Also you can ask Chris. Send him your recording sample with distortion and tell him what recorder you're using. He knows well the technical parameters of his microphones. He can assess if they are compatible with your recorder and for how loud music it fits.
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on March 14, 2020, 04:56:50 AM
Bass roll off should help if your microphone's output is too hot. But the signal is -16db in the output of recorder's preamp. I think here is no problem. (Do not use preset bass roll off. It is better to reduce lows in post because you can reduce it precisely while listening.)

The distortion could occur:
-in the microphone when the maximum loudness is exceeded. We can exclude it because your microphone specification is "Maximum Input Sound Level- 151dB"
-in the microphone when it is not properly powered. You should check your phantom power settings in the recorder. You need 48 V according specification on the web page.
-in the recorder's preamp input. This can be assessed by someone who understands the technical data. Unfortunately, I don't know this. I guess there's no trouble here.
-in the recorder's preamp output.  We can exclude this because the recording sample is -16db.
-Also check if you have set any limiter or compressor in the recorder. Turn it all off.

Try to ask a sound guy from your club for help. Explain him your problem. He could find a way how to test your microphones/recorder.
Also you can ask Chris. Send him your recording sample with distortion and tell him what recorder you're using. He knows well the technical parameters of his microphones. He can assess if they are compatible with your recorder and for how loud music it fits.

I use 48v
My recorder is new, didint brought used.
I dont use any limiters

Iv sent chris examples several times. First he said i need attenuator, now he gues i need bass rolloff. Nobody can help me..
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on March 14, 2020, 05:29:36 AM
Here is a photo. Phantom passes to mics 47.3 V  https://drive.google.com/file/d/11-J-5h9L1L74yLm1AK3soHlvVmcHQ8Z_/view?usp=sharing
Title: Re: brickwalling using XLR conections. Help!
Post by: kuba e on March 14, 2020, 09:50:29 AM
I found this on Chris web:

https://www.soundprofessionals.com/cgi-bin/gold/item/SP-CMC-4U
Quote
Powering Options:
....

3-However, if your recorder/mixer, etc. supplies phantom power, you can add the high SPL modified XLR connector option. Each mic has it's own XLR connector and cable and microphones ordered this way will not work with "plug in power" or standard battery module as shown above.

4-For intensely loud situations, consistent with highly amplified concerts at close distances to the speakers, you can add set of Ultra high SPL power modules (AT8538 or AT8531) with locking connectors between the mics and the power modules. In this configuration, the mics remain balanced. With the AT8538 modules, the microphones will plug into device (mixer, mic preamp, recorder, etc) that supplies 9-52v phantom power. With the AT8531, the microphones will run on each modules standard AA battery or 9-52v phantom power. This configuration provides the highest level of SPL capability. The output of the modules are XLRM plugs. To connect the portable recorder with miniplug input, select this cable.

Ask Chris:

1. What is the the max SPL for SP-CMC-2-XLR?
According to the above it looks like that Chris's modified xlr connectors are not designed to power mics at high SPL (sound pressure level). That would also explain why your friend has no trouble with the same microphone powered by battery box. On other hand Chris lists max SPL 151 db for SP-CMC-2-XLR on his web. That would be more than enough. (https://www.soundprofessionals.com/cgi-bin/gold/item/SP-CMC-2-XLR)

2. Have modified xlr connectors unbalanced output? I'm not sure, maybe unbalanced xlr output can cause some recorders trouble.

3. The sample with distortion has -16db headroom. Why he is suggesting bass roll off?

Feel free to resend my post to Chris.
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on March 14, 2020, 10:29:59 AM
I found this on Chris web:

https://www.soundprofessionals.com/cgi-bin/gold/item/SP-CMC-4U
Quote
Powering Options:
....

3-However, if your recorder/mixer, etc. supplies phantom power, you can add the high SPL modified XLR connector option. Each mic has it's own XLR connector and cable and microphones ordered this way will not work with "plug in power" or standard battery module as shown above.

4-For intensely loud situations, consistent with highly amplified concerts at close distances to the speakers, you can add set of Ultra high SPL power modules (AT8538 or AT8531) with locking connectors between the mics and the power modules. In this configuration, the mics remain balanced. With the AT8538 modules, the microphones will plug into device (mixer, mic preamp, recorder, etc) that supplies 9-52v phantom power. With the AT8531, the microphones will run on each modules standard AA battery or 9-52v phantom power. This configuration provides the highest level of SPL capability. The output of the modules are XLRM plugs. To connect the portable recorder with miniplug input, select this cable.

Ask Chris:

1. What is the the max SPL for SP-CMC-2-XLR?
According to the above it looks like that Chris's modified xlr connectors are not designed to power mics at high SPL (sound pressure level). That would also explain why your friend has no trouble with the same microphone powered by battery box. On other hand Chris lists max SPL 151 db for SP-CMC-2-XLR on his web. That would be more than enough. (https://www.soundprofessionals.com/cgi-bin/gold/item/SP-CMC-2-XLR)

2. Have modified xlr connectors unbalanced output? I'm not sure, maybe unbalanced xlr output can cause some recorders trouble.

3. The sample with distortion has -16db headroom. Why he is suggesting bass roll off?

Feel free to resend my post to Chris.

Thanks for helping :)
yep my mics now, according to Chris can hand 151db, but he also says that some high bass can ruin recording (exceed 151db) ;/ and now he suggesting me to replace my xlr conectors to AT8538 conectors.

i thinking my next mics will be https://www.thomann.de/gb/se_electronics_se8_stereo_set.htm, with PAD and low cut.
Title: Re: brickwalling using XLR conections. Help!
Post by: kuba e on March 14, 2020, 04:12:50 PM
It isn't serious from Chris. It looks like modified XLR connector is not able to properly power a microphone for high SPL. If you want to tape loud music you shouldn't buy SP-CMC-2-XLR. Maybe you are not alone. Chris has to correct it.

You can reterminate your mics. But it is complicated. If it's true that SP-CMC-2-XLR has lower SPL than as indicated, Chris should take them back.
I don't know SE mics. Look in the yard sale here too. Let us know how it turns out. Good luck and happy taping.
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on March 14, 2020, 06:29:09 PM
Sad that im from europe and its to expensive to send mics just for test.. becouse of duty customs. I pay 30% more every time from price sound profetional declare..
Title: Re: brickwalling using XLR conections. Help!
Post by: jerryfreak on March 14, 2020, 07:31:23 PM

yep my mics now, according to Chris can hand 151db, but he also says that some high bass can ruin recording (exceed 151db) ;/ and now he suggesting me to replace my xlr conectors to AT8538 conectors.


151 dB is extremely high, and that max SPL is higher than 80% of the rigs anybody here runs

he must be mistaken (or hes quoting you some arbitrarily high number at some very high distortion value)
Title: Re: brickwalling using XLR conections. Help!
Post by: if_then_else on March 15, 2020, 03:56:45 AM
These or the official specifications for the AT831(R) and AT831(B) versions. N.B. that the frequency response, maximum input sound levels and dynamic range values are different from the ones published for the SP-CMC-2-XLRs on the soundprofessionals.com web site. There might be some SP-specific customisations with the SP-CMC-2-XLR mics- but I doubt they would make such a big difference.

That said, "141 dB SPL, 1 kHz at 1% T.H.D." respectively "135 dB / 121 dB SPL, 1 kHz at 1% T.H.D." should still be sufficient for your purposes. Therefore, as "kuba e" has already suggested, make sure to check first whether or not the batteries in the recorder drain too quickly.

https://www.audio-technica.com/cms/resource_library/literature/c9398ce4908c7ca5/p52750_at831r_spec.pdf
https://images.static-thomann.de/pics/atg/atgdata/document/specs/115362.pdf

Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on March 15, 2020, 04:24:03 AM
These or the official specifications for the AT831(R) and AT831(B) versions. N.B. that the frequency response, maximum input sound levels and dynamic range values are different from the ones published for the SP-CMC-2-XLRs on the soundprofessionals.com web site. There might be some SP-specific customisations with the SP-CMC-2-XLR mics- but I doubt they would make such a big difference.

That said, "141 dB SPL, 1 kHz at 1% T.H.D." respectively "135 dB / 121 dB SPL, 1 kHz at 1% T.H.D." should still be sufficient for your purposes. Therefore, as "kuba e" has already suggested, make sure to check first whether or not the batteries in the recorder drain too quickly.

https://www.audio-technica.com/cms/resource_library/literature/c9398ce4908c7ca5/p52750_at831r_spec.pdf
https://images.static-thomann.de/pics/atg/atgdata/document/specs/115362.pdf

At that night i recorded three bands with to diferent batteries and result was same. One battery hold about 2,5h and i took picture that shows recorder outputs 47v.
Title: Re: brickwalling using XLR conections. Help!
Post by: jerryfreak on March 15, 2020, 06:57:51 AM
idle voltage means less than actual voltage with a mic on it

some drop as low as 30V (which really should still be fine)
Title: Re: brickwalling using XLR conections. Help!
Post by: kuba e on March 15, 2020, 08:35:34 AM
Olympus LS100 is a quality recorder. Yes, it may be a faulty piece. But rather Chris's answers and some data on the site are suspicious. His answers are unreliable. Is he manufacturer of microphones? If somebody know him, it would be good to get his direct statement.

Shpy, I would ask for a refund and send mics back. The reason for refund: SP-CMC-2-XLR max. SPL is much lower than specified. Or Chris have to seriously explain it.
Title: Re: brickwalling using XLR conections. Help!
Post by: kuba e on March 15, 2020, 08:44:52 AM
To confusion with bass roll off. I can only think of two reasons when to turn it on for ambient recording:

- You don't want to do post processing.
Then you can preventively turn on a preset bass roll off. But it's blind. Preset bass roll off may harm the recording by reducing too much bass or may be weak. It is the best to do this in post processing. You can set it exactly right according to the listening.

- The microphone output is too hot and overload your preamp/recorder.
You recognize this easily. The red LED on the recorder will flash to indicate clipping. So you set the preamp gain to a minimum. If the LED still identifies clipping, the signal at the recorder input is too hot. Also at home, you can see in the audio program that the waveform reaching 0 db and peaks are cut off.
The standard solution is to plug in an attenuators pads before recorder input. If you have no pads, you can save situation with a provisory solution bass roll off.  The electrical circuit of bass roll off is placed before the preamp in your recorder. So the signal will be attenuated by reducing the bass before entering to the preamp.

(But Shpy's case is different. Because improper power supply of microphone, the distortion occurs in a microphone's capsule.  More specifically, distortion occurs in the FET. It is an electronic component that is in a microphone's capsule. If the FET is not properly powered, it is causing distortion. This shows up just at high SPL.)
Title: Re: brickwalling using XLR conections. Help!
Post by: beatkilla on March 15, 2020, 09:32:59 AM
There are tons of recordings made with those mics terminated directly to a stereo miniplug that do not have any distortion problems.

Why not get rid of the xlr's.
Title: Re: brickwalling using XLR conections. Help!
Post by: shpy on March 15, 2020, 10:21:39 AM
There are tons of recordings made with those mics terminated directly to a stereo miniplug that do not have any distortion problems.

Why not get rid of the xlr's.

I wanted to have max SLP. and don't use battery box. I had issues before too, changed batteries after every show, because after 2h of recording it started to distort. At that time i didint knew about Low sensitivity mode and changed connections to XLR, another plus, i was thinking of is using XLR and internal mics at same time