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

[som]

I recorded Rush a few nights ago. I was way off to the left, and there was a fair amount of wind. So, I didn't expect stellar results, especially with cards. However, I am more disappointed with the results than I expected. There is a lot of what appears to be brickwalling. This is the loudest show I've recorded with the iRiver/Church combo. I was rushed getting setup (*really* slow security at the venue entrance), and when I started recording the level came on at +20, and I had the preamp up about 1/3 to 1/2 of the way or so. It did not appear to be clipping, so I left the levels alone (plus, I had the Rockbox AGC on). The result definitely sounds like the brickwalling I used to get way back when on my old MD recorder prior to going battery-box/line-in.

There's a lot of distortion, especially on the kick drum. I've recorded plenty of loud rock shows with my old D7/battery box but am new to using a pre and balancing the gain between the pre and the recorder. Is it possible that the pre was too high and sent a distorted signal to the recorder? I had a new battery in the pre, so rule that out....

Here is a sample:

http://home.grandecom.net/~myersfamily/Snippets/rush_sample%201.mp3

Any suggestions?

Any input is appreciated!

[Javier Cinakowski]

2-wire 943's   (or mini-xlr?)

your wave looks fine, no brickwalling.  The little bit of distortion I hear is from the mics IMO. 

I have pulled much worse tapes...

[som]

Mini XLR.

I posted this on the iRiver Team thread, and there was a question of whether or not the pre was three-wire. It has mini xlr inputs, so I assume so.

[prof_peabody]

How far back from the speakers?  I have brickwalled(?) the 3-wire CA-9100 before.  I was never able to pinpoint the problem.  For really loud shows you can get away without a preamp.  You could use just a 3-wire powering solution (with np preamp).  I avoid using the CA-9100 unless I know I'm going to a quieter show.  Keep an eye out in the yard sale, you should be able to find a custom 3-wire battrey box pretty cheap.  YMMV

Edit: I'm not sure brickwall is the best term.  More like high SPL distortion.  I still can't pinpoint that it was the preamp that caused it.  The AT943 will distprt under very high SPL.  AT rigs have a lot of trouble with Meg's kick drum at White Stripes shows for instance.  I have heard quite a few problems on white stripes recordings.

[SmokinJoe]

I've overloaded at-853's before, and it doesn't sound quite like this.  In that case it all sounds like mud.  This is different.  Not sure that helps.

[prof_peabody]

I've overloaded at-853's before, and it doesn't sound quite like this.  In that case it all sounds like mud.  This is different.  Not sure that helps.

I'd agree with this, mic overloading sounds different.  And I can verify that's mic overloading, most of the time I dont run a preamp...

[Kindguy]

This may be way off. But can't you record with a iriver line in & not use the internal pre at all? Seems to me you brickwalled the internal pre.

Never even held a iriver, but from past experience with other recorders. You never use the internal pre when using an external with enough gain.

[Church-Audio]

I recorded Rush a few nights ago. I was way off to the left, and there was a fair amount of wind. So, I didn't expect stellar results, especially with cards. However, I am more disappointed with the results than I expected. There is a lot of what appears to be brickwalling. This is the loudest show I've recorded with the iRiver/Church combo. I was rushed getting setup (*really* slow security at the venue entrance), and when I started recording the level came on at +20, and I had the preamp up about 1/3 to 1/2 of the way or so. It did not appear to be clipping, so I left the levels alone (plus, I had the Rockbox AGC on). The result definitely sounds like the brickwalling I used to get way back when on my old MD recorder prior to going battery-box/line-in.

There's a lot of distortion, especially on the kick drum. I've recorded plenty of loud rock shows with my old D7/battery box but am new to using a pre and balancing the gain between the pre and the recorder. Is it possible that the pre was too high and sent a distorted signal to the recorder? I had a new battery in the pre, so rule that out....

Here is a sample:

http://home.grandecom.net/~myersfamily/Snippets/rush_sample%201.mp3

Any suggestions?

Any input is appreciated!

AGC = crap recording.. Set your levels manually. AGC never works right people say it does but it does not. I think this was a case of the iriver being overloaded by my preamp. Also with the gain reduced like that there is no way you overloaded the front end on my preamp. I agree with what some people had to say in the way of a battery box when recording loud shows if you want to use my preamp as just a battery box run the input gain control at 11o'clock That is unity gain, Nothing boosted nothing attenuated. Just plug in power. When your recording a band like Rush they have drums out there ass... There is no AGC in the world that can deal with the dynamic range of a band like RUSH and produce a good quality recording. Don't be lazy use your manual gain settings
 

Chris

[petur]

AGC = crap recording.. Set your levels manually. AGC never works right people say it does but it does not. I think this was a case of the iriver being overloaded by my preamp. Also with the gain reduced like that there is no way you overloaded the front end on my preamp. I agree with what some people had to say in the way of a battery box when recording loud shows if you want to use my preamp as just a battery box run the input gain control at 11o'clock That is unity gain, Nothing boosted nothing attenuated. Just plug in power. When your recording a band like Rush they have drums out there ass... There is no AGC in the world that can deal with the dynamic range of a band like RUSH and produce a good quality recording. Don't be lazy use your manual gain settings

The original poster failed to explain he had RockBox AGC set to SAFETY, which is not your every day AGC, but a (fairly slow) routine that reduces gain when clipping risk is there (-3dB or -2dB, I keep forgetting). I also asked the original poster before and he said gain levels were the same after the show, so the algorithm never even kicked in.

What the recording does sound like is mics or pre overloading.

Now you know I have your cardoids + st9100 and I have to be really close to the PA to get something like this, and even in my case I am fairly sure it was the mics.

Which makes me point at the mics in this case as well.

So please, Chris, stop blaming Rockbox AGC Safety mode, you have to use it to understand that it is NOT TRADITIONAL AGC. Please.

And to prof_peabody: the reason I have the ST9100 was to be able to handle the louder shows because my previous pre was brickwalling.

[prof_peabody]

Chris- good to know about unity on the 9100.  I wish I had known that.

Petur-  I don't understand why you needed a preamp for louder shows.  I could understand getting a 3-wire power source or Chris' mic mod to handle these situations though.

[Arni99]

to me this sounds like overloading the analog input(line-in) of the iriver.
your at943s are very sensitive and adding a preamp with additional gain will result in overloading the analog line-in.
you don´t need a preamp for your at943 mics....this is a deadly combination...high sens 2wire mics+preamp+loud rock show.

next time use a bbox only and get the low sens mod(4.7k resistor) from Chris Church or SP.

It´s just too much input your gear is putting into the line-in at these SPL.

you can even get overloaded input when using a preamp while recording speech...yes it happened to me when i was new to preamps etc.
the levelmeters(digital stage) show no risk for clipping BUT the analog stage(line-in) gets overpowered by using too much preamp gain.


yes petur, rockbox´s "safety-clip" is something every recorder should have implemented in its software.
maybe you should change it´s name from "AGC safety-clip" to "safety-clip" or some similar non-misleading expression. ..."AGAO" automatic gain attenuation only...."ASC" automatic safety clip......."AGL"...automatic gain lowering


AGC is known as evil feature for tapers and safety-clip is NO AGC as it lowers levels but never boosts them again.

[Javier Cinakowski]

the levelmeters(digital stage) show no risk for clipping BUT the analog stage(line-in) gets overpowered by using too much preamp gain.

If we were talking about separate ADC and preamp units then I would agree with what you are saying. The ADC would be recieving an already clipped signal, but would have acceptable levels on its own....   But in the case of the iRiver, it's ADC was calibrated for the analog stage.  The ADC and level meters know what the analog input can handle and would show any clipping.  It would be impossible to clip an iriver without it showing on the level meters.  This has to be a problem with the preamp, or the mics.  I am still leaning toward distortion of the mics. Or,  perhaps the battery was low on the preamp....

[prof_peabody]

the levelmeters(digital stage) show no risk for clipping BUT the analog stage(line-in) gets overpowered by using too much preamp gain.

If we were talking about separate ADC and preamp units then I would agree with what you are saying. The ADC would be recieving an already clipped signal, but would have acceptable levels on its own....   But in the case of the iRiver, it's ADC was calibrated for the analog stage.  The ADC and level meters know what the analog input can handle and would show any clipping.  It would be impossible to clip an iriver without it showing on the level meters.  This has to be a problem with the preamp, or the mics.  I am still leaning toward distortion of the mics. Or,  perhaps the battery was low on the preamp....

I have to agree with Fred on this one...

[Arni99]

BELIEVE me, I have a preamp and a rockboxed iriver and overloaded the line-in but levels(levelmeter) were ok all the time.

[som]

The thing is, I've recorded plenty of loud shows with these mics > battery box > D7 with no problem. The pre and the iRiver are the variables (well, that and the mini-xlr mod to the mics, it used to be a mini-stereo, two wire config).

It seems most likely to me that the extra gain coming from the pre overloaded something in the iRiver, like Arni99 said. I need to do some testing at home and will report back what I find.

+T's to everyone.

Oh and Chris, you have the cutest avatar *EVER*! I get a kick out of it everytime I see it!