Topic: Bad Recording (AT943's > Church Preamp > iRiver H100)

[Church-Audio]

So this thread brings up an interesting question. The whole purpose of "three wire powering" is to make use of all three wires coming off of those AT's: the grounder, a "red" wire for each mic, and the "yellow" (or white) power cable. In two wire configurations, the grounder is shorted out to the "yellow" (or white) power cable. I'm curious then what is going on inside the CA "three wire preamp". If one of the pins is shorted out under this set-up inside the pre (like with the CA cards), the AT mics and that pre are the same as running a two wire config, except now you have interlocking connectors.

My 9100 3 wire preamp is
pin 1 ground
pin 2 signal
pin 3 bias.

I have a new version of the 9100 that has a 4.7k mod that is switchable so that you can run it in two wire * high gain * lower spl performance or * low gain * high spl performance this allows you to use the mics with acoustic recording and with really loud shows. This combined with the new 3.0 circuit that provides more power to the mics and more headroom = much lower self noise and better overall performance.

Chris

[Alchemy]

So this thread brings up an interesting question. The whole purpose of "three wire powering" is to make use of all three wires coming off of those AT's: the grounder, a "red" wire for each mic, and the "yellow" (or white) power cable. In two wire configurations, the grounder is shorted out to the "yellow" (or white) power cable. I'm curious then what is going on inside the CA "three wire preamp". If one of the pins is shorted out under this set-up inside the pre (like with the CA cards), the AT mics and that pre are the same as running a two wire config, except now you have interlocking connectors.

My 9100 3 wire preamp is
pin 1 ground
pin 2 signal
pin 3 bias.

Then this is three wire powering of course. 

Well, it's not my tape, but I think something is strange with this one. The sample sounds like typical AT mics overloading. And I've never heard a three wire tape sound this distorted before...
(that's why I replied)

EDIT: This is a moot point. Sorry to drag this out.

[Arni99]

If AGC worked there would be a lot of sound engineers out of a job.. It does not because it can not react fast enough to catch real transient spikes and it does not have "look ahead" unlike real top end compressors costing $1000's even with look ahead on the high end compressor limiters most sound engineers prefer to set the attack and release and threshold manually. I would never EVER use AGC for any recording.. It simply can not work when your very close to the threshold of the AGC it self.

one more time: rockbox´s "safety-clip"-feature is NOT the "bad" AGC you are talking about Chris .
It´s MANUAL gain control with the addition of lowering gain when peaks are around -3 or -2dB on the levelmeter.IT DOES WHAT WE DO WHEN checking levels and see manual gain setting is too high and clipping might occur.

You set gain manually and always can to this while recording with "safety-clip", you just don´t have to check levels for clipping as the software checks if the peaks are at -2db on the levelmeter and IF you set gain too high at the beginning of the show "safety-clip" LOWERS gain until there is no danger for clipping anymore. it NEVER increases gain!

As said before, you can manually set your gain anytime while using the "saftey-clip" mechanism.

I would never use AGC for taping BUT "safety-clip" is a great helping hand for taping .

[Church-Audio]

If AGC worked there would be a lot of sound engineers out of a job.. It does not because it can not react fast enough to catch real transient spikes and it does not have "look ahead" unlike real top end compressors costing $1000's even with look ahead on the high end compressor limiters most sound engineers prefer to set the attack and release and threshold manually. I would never EVER use AGC for any recording.. It simply can not work when your very close to the threshold of the AGC it self.

one more time: rockbox´s "safety-clip"-feature is NOT the "bad" AGC you are talking about Chris .
It´s MANUAL gain control with the addition of lowering gain when peaks are around -3 or -2dB on the levelmeter.IT DOES WHAT WE DO WHEN checking levels and see manual gain setting is too high and clipping might occur.

You set gain manually and always can to this while recording with "safety-clip", you just don´t have to check levels for clipping as the software checks if the peaks are at -2db on the levelmeter and IF you set gain too high at the beginning of the show "safety-clip" LOWERS gain until there is no danger for clipping anymore. it NEVER increases gain!

As said before, you can manually set your gain anytime while using the "saftey-clip" mechanism.

I would never use AGC for taping BUT "safety-clip" is a great helping hand for taping .

I have actually tested it (h120)  and it will distort when pushed to too high of a input level. With or without the "safety" I dont want to get into a pissing contest but testing gear and building it, is what I do for a living.
ps... I never said it increases gain actually.. I said all AGC'S SUCK. And they do..
Chris

[Javier Cinakowski]

I have actually tested it (h120)  and it will distort when pushed to too high of a input level. With or without the "safety" I dont want to get into a pissing contest but testing gear and building it, is what I do for a living.
ps... I never said it increases gain actually.. I said all AGC'S SUCK. And they do..
Chris

your post says nothing about why the AGC safety "sucks".

There is no pissing contest here.  People want to know why you feel the rockbox AGC safety "sucks".   It is obvious what you do for a living, quit qualifing your coments with a job tittle, and give us the facts.


 Thanks for the info about the input distorting though. 

[som]

I can see where the Rockbox AGC could possibly help in a situation where you can't check levels. And I don't see how it could really hurt. However, I think the lazy "I've got AGC turned on, it'll take care of me" approach can bite you in the ass. I'm pretty sure that's what bit me. Especially with the 1 second threshold. The high spl bass spikes were under 1 second, and that's what I'm hearing all over the recording.

This weekend I hope to run some tests. My general take at this point is that I need to turn down the gain on the iRiver and control my levels via the preamp, as much as possible. And allow some more headroom (by *manually* adjusting levels) at loud rock shows.

+T to everyone who chimed in, thanks for the help!

And a big THANK YOU to Chris Church who called me to talk over the problem!

[Arni99]

I can see where the Rockbox AGC could possibly help in a situation where you can't check levels. And I don't see how it could really hurt. However, I think the lazy "I've got AGC turned on, it'll take care of me" approach can bite you in the ass. I'm pretty sure that's what bit me. Especially with the 1 second threshold. The high spl bass spikes were under 1 second, and that's what I'm hearing all over the recording.

This weekend I hope to run some tests. My general take at this point is that I need to turn down the gain on the iRiver and control my levels via the preamp, as much as possible. And allow some more headroom (by *manually* adjusting levels) at loud rock shows.

+T to everyone who chimed in, thanks for the help!

And a big THANK YOU to Chris Church who called me to talk over the problem!

I would use as much gain as possible from the INTERNAL iriver preamp, otherwise you will distort the recording again(overload the input).
With your mics(high sensitive) a bbox is the better choice, even for silent or moderately loud music.
I had the at943s and a preamp and used it with my iHP-120. When i used too much gain from the preamp the line-in overloaded.
try what chris said: 11 o´clock position on the preamp-knob(unity gain...hopefully) and then set "safety" to +15 gain.

[Church-Audio]

I can see where the Rockbox AGC could possibly help in a situation where you can't check levels. And I don't see how it could really hurt. However, I think the lazy "I've got AGC turned on, it'll take care of me" approach can bite you in the ass. I'm pretty sure that's what bit me. Especially with the 1 second threshold. The high spl bass spikes were under 1 second, and that's what I'm hearing all over the recording.

This weekend I hope to run some tests. My general take at this point is that I need to turn down the gain on the iRiver and control my levels via the preamp, as much as possible. And allow some more headroom (by *manually* adjusting levels) at loud rock shows.

+T to everyone who chimed in, thanks for the help!

And a big THANK YOU to Chris Church who called me to talk over the problem!

I would use as much gain as possible from the INTERNAL iriver preamp, otherwise you will distort the recording again(overload the input).
With your mics(high sensitive) a bbox is the better choice, even for silent or moderately loud music.
I had the at943s and a preamp and used it with my iHP-120. When i used too much gain from the preamp the line-in overloaded.
try what chris said: 11 o´clock position on the preamp-knob(unity gain...hopefully) and then set "safety" to +15 gain.

Its actually not an issue of overloading the irivers inputs * if they are set correctly * the preamp does improve the performance of microphones connected to it. Or people would not buy my preamp Maybe you should try running some tests of your own with my preamp and an iriver see what you come up with... The preamp does nothing to increase distortion it actually decreases it when used properly .. With out AGC and by using manual settings.

Chris

[Javier Cinakowski]

I have actually tested it (h120)  and it will distort when pushed to too high of a input level.

  ->

Its actually not an issue of overloading the irivers inputs * if they are set correctly *

Chris , would you please explain the above contradiction.

With out AGC and by using manual settings.

Also, please expalin how the "safety" AGC setting could cause this distortion. (we all realize normal AGC is a problem)

[Alchemy]

I don't care AGC or not- it still does not make sense how three wire powering could distort this badly in the mp3 sample on page 1.

[Arni99]

I can see where the Rockbox AGC could possibly help in a situation where you can't check levels. And I don't see how it could really hurt. However, I think the lazy "I've got AGC turned on, it'll take care of me" approach can bite you in the ass. I'm pretty sure that's what bit me. Especially with the 1 second threshold. The high spl bass spikes were under 1 second, and that's what I'm hearing all over the recording.

This weekend I hope to run some tests. My general take at this point is that I need to turn down the gain on the iRiver and control my levels via the preamp, as much as possible. And allow some more headroom (by *manually* adjusting levels) at loud rock shows.

+T to everyone who chimed in, thanks for the help!

And a big THANK YOU to Chris Church who called me to talk over the problem!

I would use as much gain as possible from the INTERNAL iriver preamp, otherwise you will distort the recording again(overload the input).
With your mics(high sensitive) a bbox is the better choice, even for silent or moderately loud music.
I had the at943s and a preamp and used it with my iHP-120. When i used too much gain from the preamp the line-in overloaded.
try what chris said: 11 o´clock position on the preamp-knob(unity gain...hopefully) and then set "safety" to +15 gain.

Its actually not an issue of overloading the irivers inputs * if they are set correctly * the preamp does improve the performance of microphones connected to it. Or people would not buy my preamp Maybe you should try running some tests of your own with my preamp and an iriver see what you come up with... The preamp does nothing to increase distortion it actually decreases it when used properly .. With out AGC and by using manual settings.

Chris

I had your preamp chris st9100....when i turned the knob to 12 or 13 o´clock gain was added, BUT from 1 o´clock until the max. gain knob setting 5 o´clock (NO MORE GAIN WAS ADDED.....is that how your preamp should work?).
If so, it should at least be declared in some description of your pre........

From your statement above It  seems you are talking too much without having profund facts of what you are actually talking about. You always talk about "AGC" BUT we talk about safety-clip which is NOT AGC...seems you just don´t want to get this in your mind.....
sorry this is the only conclusion me and some others here can come to.

petur did the right thing and doesn´t comment anymore, he realized your statements regarding "safety-clip" are kind of "let him talk"-quality.
enjoy life
this was my last post here in this thread...don´t wanna waste time anylonger .

amen

[som]

I think Chris' bias against the AGC (even the rockbox AGC) is that if you expect it to replace the human "feel" for monitoring levels, you might end up with a situation where AGC never kicked in, but clipping occurred. Especially if the clipping spikes were under the AGC time threshold.

Just because I have an airbag doesn't mean I shouldn't use my brakes! 

[Church-Audio]

I had your preamp chris st9100....when i turned the knob to 12 or 13 o´clock gain was added, BUT from 1 o´clock until the max. gain knob setting 5 o´clock (NO MORE GAIN WAS ADDED.....is that how your preamp should work?).
If so, it should at least be declared in some description of your pre........

From your statement above It  seems you are talking too much without having profund facts of what you are actually talking about. You always talk about "AGC" BUT we talk about safety-clip which is NOT AGC...seems you just don´t want to get this in your mind.....
sorry this is the only conclusion me and some others here can come to.

Anything past 11o'clock should be adding gain but its at very small increments Anything before 11o'clock is attenuation.. So you might not notice it. But it does add gain..... lol....... if it did not I would be out of business. I think you have a "beef" with me thats ok.. But I still stand by what I said..

Anything that controls gain automatically ( reduction or boosting ) one or the other  is an AGC LOL... That's why they call it AUTOMATIC GAIN CONTROL.... Now unless they have found a new way to reduce levels with out the use of an AUTOMATIC GAIN CONTROL then its AUTOMATIC GAIN CONTROL Now some people might call this a limiter but its still controlling gain automatically so its still a form of AGC... And I meant nothing against Peter I dont know the man.. But facts are facts.



I am done with this conversation I dont know why we are arguing about AGC your entitled to your opinion as am I. So lets stop this and just agree to disagree.

Chris Church

[Liquid Drum]

GOT THE EXACT SAME problem myself at Rush last night. 

Pasted from another thread:-

''Recorded Rush last night. The sound was truly amazing (especially for an arena). I had levels on my h120 set to 12 on both channels and safety clip on (set at 1sec). After the show the levels were down to 8 so the safety clip did SOMETHING although I don't hear it. The recording had potential but imo is completely useless as the bass distorts all the way through. I don't think its the mics I just think the levels were too hot and the safety clip didn't do enough. I wish I checked my levels more but had no chance as security were 1 metre in front all night (I could have sworn he saw my mics several times lol).

What do you think of the sample? Can it be repaired to a certain degree? I know its impossible to get rid of distortion fully but if anything that COULD improve the sound even a little bit would be better than nothing.

Ah well, my first bad recording in nearly 2 years taping. Quite annoyed with myself but I guess these things happen (plus was my first time taping with my Iriver, previously used Hi MD).

Source: Sennhieser MKE40 (MM-HLSC) > SPSB-1 (No roll-off) > Iriver h120 (Rockboxed)

Heres the sample:-

http://www.mediafire.com/?arnngmjdifo


Thanks,
Simon.''


Very strange how the HLSC have distorted. Som, it can't be the safety clip not kicking in as the WAVE looks normal so in theory no distortion ever took place. Its gotta be either the mics or the battery powering the mics that caused this imo (although I could be wrong).

I'm quite annoyed as the HLSC are meant to handle very high SPL. I was about 15- 20 metre from stage aswell...

Chris, will your 4.7k modded cable help me in future and work with the HLSC mics??

Thanks.

[Arni99]

Simon, can you test the next recording with a different recorder?
I believe with a MD-line in or edirol R-09 line-in your Rush recording had turned out great without distortion in the lows.
I still believe the iriver-internal preamp got overloaded by too much signal coming in from the mics in the low frequencies.
So it´s NOT the mics or bbox´s fault IMHO.