Topic: SP-CMC-4U mics from Sound Professionals

[stevetoney]

And if the 4.7k mod is neccessary, why hasn't AT done this

Because when Audio Technica sells the mics they are terminated in a mini xlr, thus not requiring this mod.  You only need the 4.7k for mics that are terminated in a 1/8" plug.

A better question is, why doesnt SoundPros do this mod?  You will have to figure that out on your own... 

I think Soundpros is offering up a solution now.  They have an Ultra High SPL option now for purchasing these mics.

[Alchemy]

And if the 4.7k mod is neccessary, why hasn't AT done this

Because when Audio Technica sells the mics they are terminated in a mini xlr, thus not requiring this mod.  You only need the 4.7k for mics that are terminated in a 1/8" plug.

A better question is, why doesnt SoundPros do this mod?  You will have to figure that out on your own... 

The Sound Professionals don't do this mod because it raises the noise floor. If you go with the AT831 (SP-CMC-2) and give them 9 volts with a battery module, from my experience, you don't have to worry about high SPLs too much. You do lose some bass (below 80 Hz about?), but you can run the usual 1/8th jack this way at least.

[boojum]

I have spoken with some fellow back at SP and he is pretty sure that I would not need the phantom power setup; that the 9 volt battery box would be fine.  Nice attitude when he could be amping me up for another hundred or so dollars.  I will take a stab at building a 9 volt battery box from the plans at minidisc.org.  I have the electronic parts and just need a 9 volt battery box and a male 90 degree plug with a foot or so of wire on it and I am soldering.  Yes!  Love these basement junk bin projects.   

[nameloc01]

i just sent mine back wednesday to get the phantom power/xlr  modification.i aslo ordered a denecke ps-2 phantom power supply. i called audio technica (they have an office not far from me) and they told me "point blank" that the u853s were designed to use the AT power modules.they are a couple hundred bucks each.one for each mic. these only increase the handling ability (over the xlr mod) by about 5 db.which isnt very much,at least not for that money. chris assured me that the xlr mod and denecke combo would handle just about any concert situation that you would be in.(spl wise)
he also said the simple BB would be more than likely adequate also, but i am not a gambler and a lot of the shows i record are loud,so i decided to get the mod done.

[boojum]

he also said the simple BB would be more than likely adequate also, but i am not a gambler and a lot of the shows i record are loud,so i decided to get the mod done.

I will try the BB route.  If it does not work I am out a 9 volt battery and some parts.  If it does work it will proudly stand alongside my geeky homemade Jecklin, made from an Oral Roberts LP.  ;o)  If AT said that about their capsules, and did not sell phantom power supplies, I would reject what SP says.  But it is almost common knowledge that many electrets work with bias voltage ~9 volts just fine.  It seems to work enough that SP sells the BB's along with the SP-CMC-4U's.  They would be getting a lot of them back if they did not work as promoted.  So I am willing to take the low-cost chance. If it fails and it is not my building of the BB, I will let you know.  I ain't proud.   

[poorlyconditioned]

Does anyone have opinions on the new vs. older capsules?

I'm wondering if the sound has changed and/or improved any over the "classic" AT853.

Thanks,
  Richard

[Will_S]

Does anyone have opinions on the new vs. older capsules?

I'm wondering if the sound has changed and/or improved any over the "classic" AT853.

Thanks,
  Richard

The new hypers have better bass extension, and are more sensitive, than the old hypers.  Haven't compared the other patterns.

[usernox]

Hi, I'm quite new to this (taped my first concert last week  ), and I used CMC-4U->SPSB-8->line input of Edirol R-09.
While I'm quite surprised (in a positive way) with the results (I should have started this 10 years earlier  ), I do have some distortion at high levels. (sample at http://users.telenet.be/mdg/sample.wav ). The input signal never clipped, so I think it must be the mics. According to my ears, the show wasn't especially loud, so I'm thinking about that 4.7k mod, since I don't want to carry around more stuff. If I then want to record something acoustic from time to time, would that be a problem?

[Arni99]

Hi, I'm quite new to this (taped my first concert last week  ), and I used CMC-4U->SPSB-8->line input of Edirol R-09.
While I'm quite surprised (in a positive way) with the results (I should have started this 10 years earlier  ), I do have some distortion at high levels. (sample at http://users.telenet.be/mdg/sample.wav ). The input signal never clipped, so I think it must be the mics. According to my ears, the show wasn't especially loud, so I'm thinking about that 4.7k mod, since I don't want to carry around more stuff. If I then want to record something acoustic from time to time, would that be a problem?

where did you place yourself? near the soundboard or near the PA?
I NEVER had distortion with standard SP-CMC-8 cardioids(2 wire) which have the same SPL(125dB with bbox) + bbox. taped pearl jam and the chili peppers an had no problems at all. I´m always at soundboard distance to the PA.
could it be you were to close to the PA?

[Church-Audio]

Hi, I'm quite new to this (taped my first concert last week  ), and I used CMC-4U->SPSB-8->line input of Edirol R-09.
While I'm quite surprised (in a positive way) with the results (I should have started this 10 years earlier  ), I do have some distortion at high levels. (sample at http://users.telenet.be/mdg/sample.wav ). The input signal never clipped, so I think it must be the mics. According to my ears, the show wasn't especially loud, so I'm thinking about that 4.7k mod, since I don't want to carry around more stuff. If I then want to record something acoustic from time to time, would that be a problem?

where did you place yourself? near the soundboard or near the PA?
I NEVER had distortion with standard SP-CMC-8 cardioids(2 wire) which have the same SPL(125dB with bbox) + bbox. taped pearl jam and the chili peppers an had no problems at all. I´m always at soundboard distance to the PA.
could it be you were to close to the PA?

Actually the distortion of the AT 853 .. When its converted to two wire is more then 10% @ 114db @ 1k at 125 db the distortion would be closer to 20%

Chris

[hawghunter]

Hi, I'm quite new to this (taped my first concert last week  ), and I used CMC-4U->SPSB-8->line input of Edirol R-09.
While I'm quite surprised (in a positive way) with the results (I should have started this 10 years earlier  ), I do have some distortion at high levels. (sample at http://users.telenet.be/mdg/sample.wav ). The input signal never clipped, so I think it must be the mics. According to my ears, the show wasn't especially loud, so I'm thinking about that 4.7k mod, since I don't want to carry around more stuff. If I then want to record something acoustic from time to time, would that be a problem?

I would get and have had the mod done by Chris, no problems. I even recorded an acoustic gig (not shared yet) without any issues such as not loud enough. I am using his st-9100 pre though to boost the gain.

[blindman]

Actually the distortion of the AT 853 .. When its converted to two wire is more then 10% @ 114db @ 1k at 125 db the distortion would be closer to 20%

Chris, what voltage BB/Preamp did the 853 have to get those ratings?

Would that be the the distortion to expect from AT853's through your ST-9100?

Thanx,
Michael

[usernox]

Hi, I'm quite new to this (taped my first concert last week  ), and I used CMC-4U->SPSB-8->line input of Edirol R-09.
While I'm quite surprised (in a positive way) with the results (I should have started this 10 years earlier  ), I do have some distortion at high levels. (sample at http://users.telenet.be/mdg/sample.wav ). The input signal never clipped, so I think it must be the mics. According to my ears, the show wasn't especially loud, so I'm thinking about that 4.7k mod, since I don't want to carry around more stuff. If I then want to record something acoustic from time to time, would that be a problem?

where did you place yourself? near the soundboard or near the PA?
I NEVER had distortion with standard SP-CMC-8 cardioids(2 wire) which have the same SPL(125dB with bbox) + bbox. taped pearl jam and the chili peppers an had no problems at all. I´m always at soundboard distance to the PA.
could it be you were to close to the PA?

Well, I was somewhere in between... (I wanted to see something too, you know). Guess I'll first experiment a bit more, before I decide anything 

[Church-Audio]

Actually the distortion of the AT 853 .. When its converted to two wire is more then 10% @ 114db @ 1k at 125 db the distortion would be closer to 20%

Chris, what voltage BB/Preamp did the 853 have to get those ratings?

Would that be the the distortion to expect from AT853's through your ST-9100?

Thanx,
Michael

I used a 9 volt battery with a 10k resistor and a 10uf cap.. I dont use a battery box for my tests. All distortion measurements are done at 1k. There is no change in distortion from going to my preamp or a battery box because the supply voltage is virtually the same, however going from a preamp ANY PREAMP that is designed properly will improve your signal to noise ratio and provide a much closer to 0 db signal then just a battery box in MOST CASES.

Supply voltage is not the issue with distortion of most electret microphones when they are being powered between 5 and 9 volts.  People have always thought increasing the voltage to the capsule reduces distortion the plain simple truth is it does, but not by any real difference. Any voltage over 5 volts is all you need to power these mics correctly and there is virtually no difference to go from 5 volts to 9 volts the mics still distort at the same levels there might be about a 0.3% difference between 5 volts and 9 volts in the way of distortion performance.

The main reason why it has been an issue in the past is most people assumed that the 1.5 volts of plug in power was not enough for powering a electret mic and they were half right, the other reason in most cases was the shitty mic preamp that they were using as a front end for the mic capsule could not handle the input level and the end result was increased distortion.

So everyone jumped on the battery box bandwagon, There was a decrease in distortion but it was primarily from connecting the mic to the LINE INPUT, and secondarily because of the use of a voltage over 5 volts. There has been talk about increasing the voltage to 12 or 15 volts that does not do shit for distortion percentages in most electret capsules.

Chris

[kfrinkle]

So everyone jumped on the battery box bandwagon, There was a decrease in distortion but it was primarily from connecting the mic to the LINE INPUT, and secondarily because of the use of a voltage over 5 volts. There has been talk about increasing the voltage to 12 or 15 volts that does not do shit for distortion percentages in most electret capsules.

Chris

So I originally had a pair of CMC-8s that loved to distort at high SPL.  I decided to get the three wire done (by hyper-plane) and using the 9v battery box, I still get a little distortion, but it isnt nearly as bad.  I wonder if there might be something up with my mics (maybe i need to clean them or something?).  I am running CMC-8s (3-wire mod) > 9v battery box (3-wire) > MT 24/96 (mic in).

Now, one thing I thought of was using a 12v battery instead.   I wonder if those little mini 9volts are too weak for the mics (at least for the amount of time I need to use them for).  Any thoughts Chris?

I am always amazed at how some people say their CMC-8s never distort, yet mine will.