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Gear / Technical Help => Ask The Tapers => Topic started by: som on August 29, 2007, 10:13:10 PM
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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!
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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...
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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.
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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.
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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.
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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...
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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.
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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
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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.
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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.
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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.
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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....
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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...
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BELIEVE me, I have a preamp and a rockboxed iriver and overloaded the line-in but levels(levelmeter) were ok all the time.
;)
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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!
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BELIEVE me, I have a preamp and a rockboxed iriver and overloaded the line-in but levels(levelmeter) were ok all the time.
;)
I don't doubt you had problems, but it had nothing to do with the iRiver if the levels were ok. BELIEVE the technical aspects of an intergrated preamp/adc, not me....
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I gotta agree that a preamp is not needed for loud shows, but a BB is essential.
my set up for loud shows dpa4061's>spsb3>line in on d100
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a new 9v battery is all you need.....
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a new 9v battery is all you need.....
If I had to put money money on an explanation it would be this, with slightly overloaded mics as a close second. Sure the 943 can handle high SPLs, but will have trouble at some really loud shows. Don't make me upload samples...
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I recorded Tool with DPA4061>STC-9100>M1 (line in) and I had the gain too high on the pre and even though the levels were fine, it completely distorted. Tool was extremely loud, so I had no business turning up the gain on the 9100. I should have had it at "unity" or less.
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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.
Umm I have used it I have tested it I have owned many iriver h120's and the AGC sucks.... lol.
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I put in a new 9v the day of the show.
I'm gonna do some testing and see if I can recreate the scenario. Hell, I'll even use a Rush CD!
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Umm I have used it I have tested it I have owned many iriver h120's and the AGC sucks.... lol.
::)
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I put in a new 9v the day of the show.
I'm gonna do some testing and see if I can recreate the scenario. Hell, I'll even use a Rush CD!
Maybe you had a bad 9V battery. I know Moke has had this happen to him.
I agree with Chris, the AGC/ASAO feature is not great. It's good for maybe the first couple times you run a rig, but once you get used to your rig you can dial in better on your own. If you get unlucky and end up next to a screamer for a few seconds, the AGC will really crank down the gain permanently for the rest of the show... YMMV
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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.
Petur-
I've come to accept that the Rockbox AGC Safety setting will never be thought of any differently than the standard AGC utilized on most recorders throughout the years. I know when I first got my pcm-m1 and was learning about the settings, the use of AGC was always a bad thing. There have been years of negative discussions about AGC use, and the Rockbox AGC Safety feature is often lumped in with 'typical AGC' in peoples minds. Perhaps you developers could rename the feature as 'Clip preventer' or similar (j/k) ;) Whenever tapers hear the term 'AGC', it automatically brings negative connotations. Probably always will.
+T
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If you get unlucky and end up next to a screamer for a few seconds, the AGC will really crank down the gain permanently for the rest of the show
There is a setting that allows you to change the clip-time. Set it its highest and this situation will not be as big of a problem.
If the screemer does go crazy for an extended time, it will indeed reduce that gain. However, there is no logical reason for someone to suggest the AGC safety clip caused the distortion in question. Nor is there a logical reason to say that it sucks
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...and when I started recording the level came on at +20...
So - is this in addition to the gain from the preamp...?
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...and when I started recording the level came on at +20...
So - is this in addition to the gain from the preamp...?
Hope I'm not speaking out of turn, but as I understand it.....Yes.
I have not run that rig before, but if I was going to I would try to leave the iRiver gain as low as possible (even at 0 if I could get away with it and get decent levels with the pre).
Edit: I guess if you wanted to run 'AGC Safety', you would have to use some gain on the iRiver in order to see the benefits. However, I would recommend trying the iRiver gain at a setting more like 10 than 20.
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...and when I started recording the level came on at +20...
So - is this in addition to the gain from the preamp...?
Hope I'm not speaking out of turn, but as I understand it.....Yes.
I have not run that rig before, but if I was going to I would try to leave the iRiver gain as low as possible (even at 0 if I could get away with it and get decent levels with the pre).
Edit: I guess if you wanted to run 'AGC Safety', you would have to use some gain on the iRiver in order to see the benefits. However, I would recommend trying the iRiver gain at a setting more like 10 than 20.
Is there a "no gain" or unity gain setting on the Iriver Line In...? If so - thats where you should be - It sounds like you are adding an additional 20db to your pre's signal - and likely overloading the Iriver Line Input. Try setting it to 0db and see if it still passes signal...(Im sure others more familiar with the device will chime in)
With the JB3 (for example) - you set it at "0db" - no gain added, no gain subtracted...just whatever the preamp will give...
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Yep, that was 20 on the iRiver, in addition to the pre gain. When I turned it on it was at +20 and I was in a rush (no pun intended) and it did not appear to be clipping so I left it alone, thinking that the AGC (or whatever it *should* be called) would kick in if needed. I thought that was a lot of gain but it was not clipping, so....
One thing I've wondered is if the 1 second threshold on the AGC allowed some distortion to "slip through" without activating the AGC. The distortion is of pretty short duration, but is pretty pervasive throughout.
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Is there a "no gain" or unity gain setting on the Iriver Line In...? If so - thats where you should be - It sounds like you are adding an additional 20db to your pre's signal - and likely overloading the Iriver Line Input. Try setting it to 0db and see if it still passes signal...(Im sure others more familiar with the device will chime in)
Not only is there a 0 gain setting, but you can even use a 'negative gain' setting (I'm assuming it actually attenuates). If you were wanting to use the rockbox 'AGC Safety' feature, however, you would need to use a little gain on the iRiver so that it would 'bump down' your gain setting just enough that it doesn't clip.
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It may not appeared to be clipping - but if you had properly gained recorder to compare it with, you would see the subtle difference in the way the levels move...generally, meters will lack the proper "bounce" - visually speaking...
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Is there a "no gain" or unity gain setting on the Iriver Line In...? If so - thats where you should be - It sounds like you are adding an additional 20db to your pre's signal - and likely overloading the Iriver Line Input. Try setting it to 0db and see if it still passes signal...(Im sure others more familiar with the device will chime in)
Not only is there a 0 gain setting, but you can even use a 'negative gain' setting (I'm assuming it actually attenuates). If you were wanting to use the rockbox 'AGC Safety' feature, however, you would need to use a little gain on the iRiver so that it would 'bump down' your gain setting just enough that it doesn't clip.
So you have to actually add gain to activate this feature? Is that by design? Why wouldn't it work into the negative gain range?
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So you have to actually add gain to activate this feature? Is that by design? Why wouldn't it work into the negative gain range?
I'm not sure if you have to add gain in order to use the 'AGC Safety' feature. In theory, I guess you could set the gain at 0 with the 'AGC Safety' feature enabled, and it would bump down to a negative gain setting to prevent clipping if you had the level on the pre too hot.
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So you have to actually add gain to activate this feature? Is that by design? Why wouldn't it work into the negative gain range?
I'm not sure if you have to add gain in order to use the 'AGC Safety' feature. In theory, I guess you could set the gain at 0 with the 'AGC Safety' feature enabled, and it would bump down to a negative gain setting to prevent clipping if you had the level on the pre too hot.
I cant see the need to add gain (at the recorder) AT ALL when using an external pre like CA9100...unless you are recording hummingbirds or something...
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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!
Ok.. I analyzed this again and most of the distortion is happening at the low end of the spectrum this would seem to indicated I was wrong with my first statement that it was AGC, not saying it could not have been the AGC pumping.. But there is very little distortion in the top end this suggest that its not my preamp rather its the mics overloading from too much low frequency.. These mics have a high tolerance for SPL at least all the mics I have measured. You might want to consider my 4.7k mod in to your mics... I can make you up a cable with the mod in it so when your recording quiet stuff the mod can be (taken out) and when your recording loud stuff you can run the mod in line with your mics. I will do this at cost.. no mark up for labour I am sure this will solve the problem..
Chris
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I cant see the need to add gain (at the recorder) AT ALL when using an external pre like CA9100...unless you are recording hummingbirds or something...
I agree completely. Espescially if the 'AGC Safety' feature is still functional when the iRiver gain is set to 0 (Petur or home testing could verify this). I would assume that the gain provided by Chris' pre is cleaner than the gain provided by the iRiver pre.
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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.
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Ok.. I analyzed this again and most of the distortion is happening at the low end of the spectrum this would seem to indicated I was wrong with my first statement that it was AGC, not saying it could not have been the AGC pumping.. But there is very little distortion in the top end this suggest that its not my preamp rather its the mics overloading from too much low frequency.. These mics have a high tolerance for SPL at least all the mics I have measured. You might want to consider my 4.7k mod in to your mics... I can make you up a cable with the mod in it so when your recording quiet stuff the mod can be (taken out) and when your recording loud stuff you can run the mod in line with your mics. I will do this at cost.. no mark up for labour I am sure this will solve the problem.
Chris
Sounds like you solved the problem, Chris. +T
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.
As Petur eluded to earlier: It apears that you are referring to 'typical' AGC, and not the 'AGC Safety' feature of rockbox. I assume that even with 'AGC Safety' enabled it is possible to have a short section of clipping while the reduction in gain is being made internally. The amount of clipping would be increased or decresed, depending on the sensitivity setting being used.
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It sounds like the Rockbox AGC:
1 - Only lowers the gain.
2 - Does automatically...what you might do yourself...sort of...
I still favor controlling levels at the pre...not the recorder...
seems like it would be too easy to activate the AGC by accident or random PA noise - and then have the rest of the recording too low.
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seems like it would be too easy to activate the AGC by accident or random PA noise - and then have the rest of the recording too low.
Just set the clip time higher. The AGC won't kick in on short random noises.
Like Mr. Church I am not a fan of AGC in general. The rockbox AGC "safety" is an exception...
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The ONLY time that I would use the AGC Safety feature would be if I was in an 'unopen' environment, and I did not want to appear to be checking / adjusting levels. If I'm in an open setting, it's all in my hands.
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This is what my tool recording with AT853's sounded like
SPL for the bass was just way too high, overloading the mics
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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.
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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.
Search for 3-wire on ts.com. There was a lengthly thread that even had schematics. I think it was in the preamp and powering subforum.
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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
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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.
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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 ;).
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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
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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.
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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!
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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.
;)
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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
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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)
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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.
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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 ;D.
amen ;)
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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! ;)
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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
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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.
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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.
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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.
So do you think running an external pre instead of a bb would help in this case on using the iriver?
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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.
So do you think running an external pre instead of a bb would help in this case on using the iriver?
I think a different recorder (MZ-RH1, Edirol R-09) OR a 4.7k mod to your HLSC-1 ground conductor(reduces mic´s signal by -12 to -15dB) would solve the problem for high SPL in big arenas.
Try the 4.7k mod...takes 15 minutes and you are done. It will reduce the hot signal provided by the HLSC mics and therefore not overload the iriver´s analog input(line-in). With the 4.7k mod you´ll need more internal amplification, so I´d start with +20dB and "safety-clip" instead of +8db(your Rush setting in the end of the show).
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Well, I had my 2nd outing with the Church Preamp, with much better results. This was Jethro Tull, 6th row center. Not as heavy as Rush, but a few songs rocked pretty hard, and I don't have any of the distortion I had with Rush.
This time out I had the iRiver gain at 10 (vs. 20), and adjusted the levels via the Church preamp (I had to crank it close to all the way up). I used the Safety AGC, but set it at a lower time threshold. By the end of the show it had bumped the level down to 9.5.
Looking back , I think that I actually may *not* have had the Safety AGC on at Rush. I haven't messed with the iRiver since then, and when I turned it on I saw that the AGC was off. Also, the sample I posted was after doing some minor editing in Audacity, and I wonder if saving the file could have possibly somehow removed the tell-tale signs of clipping.
ANYWAY,
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I'm confused... ???