Rockbox Technical Forums

Support and General Use => Recording => Topic started by: DisturbedPyro on March 20, 2008, 08:01:55 PM

Title: edit: first test run!
Post by: DisturbedPyro on March 20, 2008, 08:01:55 PM
ok, i got my iriver h320 all rockboxed up. and i looked through the iriver faqs about recording settings and set everything to what it said but i would just like to get further advice.

i will be stealthing at loud rock shows with an iriver h320 and chris church STC-11 mics and a BAT-2B. some recordings will be at smaller venues (local bands) but the real important ones will be at larger ones. so i want to know what settings would be best for my equipment and the type of show i am going to record. also, i had some questions as to what stuff is for that i didnt see an explanation of in the faqs. thanks again for all the help

1. i know the frequency deals with the sample rate. but does this effect the overal quality of the recording? i see in the faqs it is suggested to be set at 44.1. is this always the case? or to get the best recording possibvle should it be higher? if this depends, when should it be changed to the others?

2. should channel ever be changed to mono? or is stereo always good?

3. when setting the range of my clip meter displays, the faqs say -30dB & 0dB. will this be appropriate for my recording needs? ie - a loud rock show at large and small venues?

4. what is the best setting for high and low gain? what should i set Gain Left and Gain Right at?

5. i hear that a lot of recordings sound like the bass is too high. how can this be avoided? the sound settings only changes when listening to playback right? it has no effect on recording

basically, should i change the settings in any way from what the faqs suggest for my equipment and the type of show i will be recording? thank you


well, i had my first test run last night! CCR concert, it was last minute, i didnt even know a couple of my friends were goin until like 2 hrs before we were to leave. it was only 10 bucks to get in and it was a good opportunity to test out my gear, so i went. im very pleased with the results, the quality is great. but there was no one around us so it wasnt a good test for talking, clapping, ect. you can clearly hear my voice and my two friends around me so i know that will be a lot more of a disturbance when people are all over the place yelling and everything. however, the band was very quiet so maybe at a louder show peoples voices wont show up as much. i guess ill have to see

only bad thing about the recording is its a little on the quiet side. i know i can boost the sound in editing programs but i dont want to distort the quality any by increasing the volume. is there any best way to increase the volume without distorting the sound?

heres a link to a clip from the opening local band: http://www.sendspace.com/file/gs49u5
Title: Re: iriver h320 (w/ rockbox) help with recording settings please
Post by: Davide-NYC on March 20, 2008, 09:18:54 PM
Stay with the FAQ as far as I can tell.

1. Higher bitrate = better.

2. Stereo if you have two mics.

3. Loud rock shows tend to have less dynamic range so you *could* bring the peak meter range lower limit up a bit. Also you could bring down the the higher limit for added safety margin. But I would just leave them be.

4. That depends on your mics, your positioning, the venue, the band, the soundman, etc etc etc.

5. You could get a battery box with a bass roll-off switch.



Title: Re: iriver h320 (w/ rockbox) help with recording settings please
Post by: DisturbedPyro on March 20, 2008, 09:38:29 PM

Stay with the FAQ as far as I can tell.

1. Higher bitrate = better.

2. Stereo if you have two mics.

3. Loud rock shows tend to have less dynamic range so you *could* bring the peak meter range lower limit up a bit. Also you could bring down the the higher limit for added safety margin. But I would just leave them be.

4. That depends on your mics, your positioning, the venue, the band, the soundman, etc etc etc.

5. You could get a battery box with a bass roll-off switch.
1. is there a way to get the frequency higher than 44.1?

4. so should i leave it at 0 since im a newbie. or is there a number i could set them to that would generally be good?

5. im getting a BAT-2B. i dont know if that has a bass roll-off switch or not. i dont have it yet. but turning down thet bass in sound settings doesnt effect recording options right? so there is no way to make the recording less sensative to bass by altering an option in the settings? that seems strange, but then again, im new to this so, what do i know ???
Title: Re: iriver h320 (w/ rockbox) help with recording settings please
Post by: petur on March 21, 2008, 04:59:18 AM
making rockbox less sensitive to bass in software would be a useless thing to do anyway, because the only reason you want to do bass roll-off is to prevent your mics from overloading the input circuits of your recorder (h300).
If the show is very bass-heavy and you have sensitive mics, it is a wise thing to do, but OTOH I use Chris Church's cards with his st-9100 pre-amp and do not use the bass roll-off. YMMV

As you do not have external gain change possibilities, set AGC mode to AGC-Safety, Gain to +15 or 20dB and enjoy the show. At worst, the first parts may have slight overloading while AGC slowly turns down gain.

AGC time constant is a bit of a discussion: I have it set to 200ms for fast response, but that means it also responds to shouters and clappers...


have fun!
Title: Re: iriver h320 (w/ rockbox) help with recording settings please
Post by: DisturbedPyro on March 21, 2008, 09:22:29 AM
yeah i have AGC mode set to AGC-Safety. the range of my clip meter is: -30dB & 0dB (thats what i saw in iriver taperssection faqs.) but what about Gain Left and Gain Right? what is a good number to set those to?
Title: Re: iriver h320 (w/ rockbox) help with recording settings please
Post by: Febs on March 21, 2008, 11:44:34 AM
It's hard to give a specific answer to that question, because it is going to depend so much on the particular event you are recording, the sensitivity of the mic you are using, etc.  In general, you'll want to set the gain as high as possible without clipping.
Title: Re: iriver h320 (w/ rockbox) help with recording settings please
Post by: DisturbedPyro on March 21, 2008, 12:37:05 PM
well the events will all be loud rock shows, the only difference will be the size of the venue. theres a local place that is very small but i will be taping large arenas for mainstream rock bands also. can i set the sensitivity of the mic somehow? or does it just depend on the type of mic? as i said i will be using chris church STC-11 mics. im not even really sure what causes clipping to begin with

so if i dont get a clear idea of the Gain Left and Gain Right, i will just leave them alone and leave them both at 0. is that ok or would that be a bad choice?
Title: Re: iriver h320 (w/ rockbox) help with recording settings please
Post by: DisturbedPyro on March 24, 2008, 09:03:48 AM
i want to try this out at home, but the problem is, i wont know what the meter should look like so i wont know how to change it if it is a problem. the bars jump back and forth during loud and soft parts, but what is it supposed to look like? how do i know when i got it where it should be?

ive been told elsewhere to: "crank the gain up to the max, and AGC-safety will carefully adjust down until you have the optimal gain." so i should set it at 48.0 dB? would this be best for someone that doesnt know what theyre doing? lol

obviously i want the best gain on both channels. but how do i know what the best gain is? thats my problem, i dont know how to tell what this stuff should look like so i can say "there, thats how it should be" i wouldnt know i had it right even if i saw it
Title: Re: iriver h320 (w/ rockbox) help with recording settings please
Post by: Davide-NYC on March 24, 2008, 11:23:17 AM
You need to do some basic audio research. This thread is now fully outside of the scope of rockbox. There are plenty of basic guides out there to explain the concepts of gain, clipping, etc. After you've done that there is no substitute for experience. Go forth and make recordings! :)
Title: Re: iriver h320 (w/ rockbox) help with recording settings please
Post by: petur on March 25, 2008, 04:41:53 AM

yeah i have AGC mode set to AGC-Safety. the range of my clip meter is: -30dB & 0dB (thats what i saw in iriver taperssection faqs.) but what about Gain Left and Gain Right? what is a good number to set those to?


Gain L/R are just ways to set the gain for Left and Right individually. Unless you need to correct balance, keep changing L/R together. Nothing that can't be fixed in post-processing anyway ;)
Title: Re: iriver h320 (w/ rockbox) help with recording settings please
Post by: DisturbedPyro on March 26, 2008, 04:09:01 PM
yeah i know they should be the same, i just dont know what they should be the same at. but ive heard that around 20 is a good starting place for a loud rock show, then AGC safety will lower my levels accordingly
Title: Re: iriver h320 (w/ rockbox) help with recording settings please
Post by: petur on March 27, 2008, 04:07:59 AM
The values you see are in dB, and show you how much the signal is amplified.

the difference between L+R and the individual L and R gain settings is that when you change L+R (both are selected by the bar) they change together. So just have L and R gain the same and then change them together.

Values from 0 to 24dB are analog gain, anything above or below is done digitally, but it is done in the ADC before the signal is converted to 16bit, so it still might be better to use the full range in stead of limiting yourself to 24dB and doing the rest in post-processing.

I would certainly not try to go above 20dB as the input signal gets noisy. However, if you do not have a variable pre-amplifier between mics and iriver, there is not much you can do but use the gain range that the iriver offers. So stick it to some value and let AGC-Safety do the rest. Make a note of the gain values at the end of the show so you know how much gain you really needed:
if it stayed at the initial value, you might need more gain or an external amplifier.

Beware that your first recordings may fail horribly, it is a bit trial and error ;)

good luck
Title: Re: edit: first test run!
Post by: DisturbedPyro on March 29, 2008, 10:45:53 AM
well, i had my first test run last night! CCR concert, it was last minute, i didnt even know a couple of my friends were goin until like 2 hrs before we were to leave. it was only 10 bucks to get in and it was a good opportunity to test out my gear, so i went. im very pleased with the results, the quality is great. but there was no one around us so it wasnt a good test for talking, clapping, ect. you can clearly hear my voice and my two friends around me so i know that will be a lot more of a disturbance when people are all over the place yelling and everything. however, the band was very quiet so maybe at a louder show peoples voices wont show up as much. i guess ill have to see

only bad thing about the recording is its a little on the quiet side. i know i can boost the sound in editing programs but i dont want to distort the quality any by increasing the volume. is there any best way to increase the volume without distorting the sound?

heres a link to a clip from the opening local band: http://www.sendspace.com/file/gs49u5
Title: Re: edit: first test run!
Post by: DisturbedPyro on March 31, 2008, 07:22:47 PM
anyone? :-\
Title: Re: edit: first test run!
Post by: Llorean on March 31, 2008, 07:48:23 PM
Please, see our posting guidelines. You are asked specifically not to bump.