Topic: 96kHz recording with JB3

[Karl]

I've been thinking about it, and it can be done, but it would take a lot of work and be a PITA.  But I thought I would bring up the thoughts anyways.  You would need two JB3's (which I don't have, but I know a lot of people do). 

Thus far, we know that the JB3 will take a 96k signal.  The file header is written wrong, that needs to be changed, but apparently that's easy.  The problem is, is that 96k is too fast for the JB3 processor, so it results in glitches and dropouts.  Now I'm going to go on the theory that lightning never strikes the same place twice.  So, if you were recording with two JB3's at the same time with the same signal (optical splitter), then both recordings would end up with random dropouts, but not in the same place.  Here's where the hard work comes in--you would need to load both files into some sort of wav editor where you can do two tracks of stereo at the same time, and be able to line the files up against each other (I can do it in Samplitude).  You would then have to painstakingly go through and take all of the good parts and throw away the bad parts, save them as one file, then there you go!  A clean 96k recording.

Food for thought.

[jaguaracer]

interesting...
[dumb question] Are we sure the drop outs be random though?  Maybe the dropouts are at the same time marks for all JB3 because of the physical limitations? ie could be that after 5 seconds of 96 recording, the physical limitations of the JB3 cause all JB3s to drop out at exactly that point, then 15 seconds later, all JB3 drop out again[/dumb question] This is maybe far-fetched, but I'm there are people out there with a couple JB3s who could test this out. I am interested too. 
edit: although I guess one JB3 is all you would need to test this. Just run two separate 96 recordings and see exactly where the drop off occurs. Although if the drop outs do occur at exactly the same spots that wouldn't be conclusive evidence as two JB3 could produce different drop out points.

[Karl]

But then you would just start the recordings at two different times.

[jaguaracer]

yeah, but you would only be testing where the drop outs are on both.
If they both drop out at say exactly 0:05.85 then there might be a problem but if they drop out at completely different spots, you are in business then.

[admkrk]

that all sounds like a lot of work. i'm not sure yet, but i don't understand why recording at a higher frequency is any better? i don't know of any mics that do better than 20-20, so it seams to me that you aren't gaining anything above 44.1.  the only advantage i can see is in increasing the bit rate.

the sampling therem states that a continuous band-limited signal can be replaced by a discrete sequence of samples w/out loss of any information and describes how the original continuous signal can be reconstructed from the samplles; furthermore, the therem specifies that the sampling frequency must be at least twice the highest signal frequency.

the way i read that, unless you have a mic capable of picking up a 48khz signal, what's the points.

[creekfreak]

that's crazy talk

[admkrk]

like it says,        i'm an idiot!    i understand raising the bit rate, but just haven't figured out any advantage to raising the frequency?

[BC]

that all sounds like a lot of work. i'm not sure yet, but i don't understand why recording at a higher frequency is any better? i don't know of any mics that do better than 20-20, so it seams to me that you aren't gaining anything above 44.1.  the only advantage i can see is in increasing the bit rate.

the sampling therem states that a continuous band-limited signal can be replaced by a discrete sequence of samples w/out loss of any information and describes how the original continuous signal can be reconstructed from the samplles; furthermore, the therem specifies that the sampling frequency must be at least twice the highest signal frequency.

the way i read that, unless you have a mic capable of picking up a 48khz signal, what's the points.

some mics have extended freq. response up to 40 or 50 KHz, Schoeps CMC6xt, Sennheiser MKH800 come to mind.


Although regarding the original post it seems lile too much work to just gain some extra frequency response when most PA systems are not putting out anything over 15KHz anyway.

[mmmatt]

What would it take to record @ 24bit with a jb3?  I don't know enough to even guess what would have to be done.

Matt
 ***edit*** ...and does a 48K recording mean that is the highest audible frequency it can record?  I thought there was more to it than that.  Isn't that the sample rate... like how often the signal needs to refresh itself before it saves or something like that?  Like I said I have very limeted knowlege of this kind of thing.

Matt

[Brian Skalinder]

What would it take to record @ 24bit with a jb3?

Can't be done.

and does a 48K recording mean that is the highest audible frequency it can record?

Highest capturable frequency at a given sample rate = sample rate / 2.  So 24 kHz is the highest we can achieve at 48 kHz sample rate.  At 44.1 kHz sample rate, highest frequency would be 22.5 kHz.

[admkrk]

that all sounds like a lot of work. i'm not sure yet, but i don't understand why recording at a higher frequency is any better? i don't know of any mics that do better than 20-20, so it seams to me that you aren't gaining anything above 44.1.  the only advantage i can see is in increasing the bit rate.

the sampling therem states that a continuous band-limited signal can be replaced by a discrete sequence of samples w/out loss of any information and describes how the original continuous signal can be reconstructed from the samplles; furthermore, the therem specifies that the sampling frequency must be at least twice the highest signal frequency.

the way i read that, unless you have a mic capable of picking up a 48khz signal, what's the points.

some mics have extended freq. response up to 40 or 50 KHz, Schoeps CMC6xt, Sennheiser MKH800 come to mind.


Although regarding the original post it seems lile too much work to just gain some extra frequency response when most PA systems are not putting out anything over 15KHz anyway.

i didn't say there weren't any mics that could do it, just that i wasn't aware of them.

and, exactly my point.

24 bit compared to 16 bit,      that's a different story

[mmmatt]

so all I'm getting by recording at 48k instead of 44.1 is a nicer sounding glass clink by the bar?
That just doesn't seem right.

Matt

[admkrk]

so all I'm getting by recording at 48k instead of 44.1 is a nicer sounding glass clink by the bar?
That just doesn't seem right.

Matt

not nessessarily,   as i understand it, people don't hear frequencies above 20khz to begin w/, so unless you're recording a dog wistle for the pooch, you won't "hear" a difference either way. that doesn't mean you can't "feel" the sound. i'm sertain that although i can't hear it i can feel sounds below 20hz, so why shouldn't it work the same way at the other end? it's more of a subliminal deal. it's the bit rate that needs to be higher to get a fuller sound.  unless someone can convince me otherwise. 

[mirth]

I thought that sample rate has nothing to do with the frequency response of your mics... Meaning, it can be compared to frame rate when making a video - higher frame rates mean that more data is 'captured'.

this has me cornfuzed...

[nic]

I thought that sample rate has nothing to do with the frequency response of your mics... Meaning, it can be compared to frame rate when making a video - higher frame rates mean that more data is 'captured'.

this has me cornfuzed...

in your analogy, the frame rate would be comparable to bit-rate in audio, not sample size