Why the doubled tracks in 96k mode?

P

Parlor Music

New member
I just upgraded my converters with the EC-2 boards. I
also updated the software to the latest. I began a
recording session last weekend using 24/96 for 12
tracks. I used the analog inputs for receiving
outboard preamp signals, while the outputs feed a
mixer for monitoring purposes. We recorded guide vocal
(track 1), guide guitar (track 2) and a click track
(track 3).

After the session, I transfered the tracks to my PC
via the Fireport. What I found was that tracks 1 & 2
were the vocals, tracks 3 & 4 were guitar and tracks 5
& 6 were the click track! Why was each track doubled?
I realize that the amount of available tracks are
halved when doubling 44.1 or 48k sample rates, but I
wasn't expecting the available tracks to be halved
TWICE.

Any suggestions?
 
Thats about it. two tracks of 48 equalling the 96. All the converters do is make available the 96k for analog mixers. If you had a digital mixer you can have 96k from beggining. People are often under the assumption that the converters will give them 24 tracks of 96k. Regardless of your setup, the most tracks you can have at 96k is 12 tracks
 
vwodwo22 said:
Thats about it. two tracks of 48 equalling the 96. All the converters do is make available the 96k for analog mixers. If you had a digital mixer you can have 96k from beggining. People are often under the assumption that the converters will give them 24 tracks of 96k. Regardless of your setup, the most tracks you can have at 96k is 12 tracks
Click to expand...

Yes, I know that 12 tracks is max at 88.2 & 96k. The problem is that if I enable record for track #1, it somehow shows up on track #1 AND track #2 when I transfer files to my PC with the Fireport. 12 tracks appear for available record enabling which is what's expected. If recording to each one of the 12 available tracks uses 2 tracks, then I really only have a glorified 6-track recorder! Shouldn't I be able to record ONE track for EACH of the 12 available tracks at 96k? It seems odd that I can record to 24 tracks at 44.1 & 48k, but only 6 at 88.2 & 96k.
 
I'm not sure what you mean. I would think that track 7 to 12 would show up as 13/14 15/16 17/18 19/20 21/22 23/24 respectively. Have you tried recording more than six tracks?
 
Soundbyte said:
I'm not sure what you mean. I would think that track 7 to 12 would show up as 13/14 15/16 17/18 19/20 21/22 23/24 respectively. Have you tried recording more than six tracks?
Click to expand...

I'll try again...
I set up a project at 24/96 with the max setting of 12 tracks. I record enable tracks 1-3 for vocal, guitar and click (each on their own channel). When done, I transfer the files to my PC with the Fireport. That's when the tracks appear doubled. Tracks 1 & 2 are duplicates what was track 1 on the HD24, tracks 3 & 4 are duplicates of what was track 2, and tracks 5 & 6 are duplicates of what was track 3 in the HD24.

And to make it more interesting, the wave forms appear flat on the bottom and very little peaks and valleys on top when viewed in my DAW software. It sounds fine, but it's more challenging to edit. I've worked with high sample rates quite a bit, but never before encountered this.

None of it makes sense. I'm wondering if somehow the Input Normalling got changed to a 2-bus setting. I did update the software just a couple of days before the recording and I'm thinking that maybe it happened then.

I guess I'll just record this project in 48k until I get it figured out.
 
The only thing I can suggest is to make sure the FST/Connect software for the FirePort is set to 96kHz. The unit stores high speed data across 2 tracks at a time in a split sample arrangement. I don't know for sure, but the tracks are probably interlaced between the tracks to get the higher bandwidth. If the DAW or FirePort is not configured for high speed transfer they will appear as two seemingly duplicate tracks instead of one.
 
Soundbyte said:
The only thing I can suggest is to make sure the FST/Connect software for the FirePort is set to 96kHz. The unit stores high speed data across 2 tracks at a time in a split sample arrangement. I don't know for sure, but the tracks are probably interlaced between the tracks to get the higher bandwidth. If the DAW or FirePort is not configured for high speed transfer they will appear as two seemingly duplicate tracks instead of one.
Click to expand...

That makes sense. I just don't remember seeing any such setting in the Fireport software. I'll check it out when I get home this evening. I remember reading somewhere that the samples are alternated between two channels at the high sample rate settings. That's why the number of available channels is halved. I would think that it writes the extra samples to the UNAVAILABLE tracks rather than the available ones. Who knows...
 
Have you tried calling Alesis? They have been very helpful every time I have called. (401)658-5760.

If you call, please post the results!
 
hasbeen said:
Have you tried calling Alesis? They have been very helpful every time I have called. (401)658-5760.

If you call, please post the results!
Click to expand...

I'm getting to that point. First, I have to get my HD24 back home (it's 2 states away) so I can check some of the settings to see if they somehow got changed when I updated the software. Then I'll RTFM one more time before calling. I'll deffinately post the results. Obviously this is something uncommon.
 
Parlor Music said:
I would think that it writes the extra samples to the UNAVAILABLE tracks rather than the available ones. Who knows...
Click to expand...

It is important not to think of track numbers as being unavailable tracks in this situation. They are all available, but the numbers are different. The numbers that are assigned are arbitrary and you still have 12 tracks not 6. It is this way because this data has to ultimately be transferred via the lightpipe ports using the split-sample standard. Let us suppose it used the upper tracks instead, that would mean that track-1 would also use track-13 instead of 2. You would need two ADAT lightpipe connections just to transfer one track.

The behavior you are experiencing is covered in the EC-2 manual in appendix A-11. My money is still on something other than the HD24 not being configured right for high speed.
 
Soundbyte said:
It is important not to think of track numbers as being unavailable tracks in this situation. They are all available, but the numbers are different. The numbers that are assigned are arbitrary and you still have 12 tracks not 6. It is this way because this data has to ultimately be transferred via the lightpipe ports using the split-sample standard. Let us suppose it used the upper tracks instead, that would mean that track-1 would also use track-13 instead of 2. You would need two ADAT lightpipe connections just to transfer one track.

The behavior you are experiencing is covered in the EC-2 manual in appendix A-11. My money is still on something other than the HD24 not being configured right for high speed.
Click to expand...

Yes, that's exactly what is happening. However, I'm not using ADAT lightpipe. It's all analog going into the HD24, then I transfer the files to my PC by plugging the hard drive from the HD24 into the Fireport.
 
Yes I know, but the same rules apply because that is the way the tracks are stored on the drive. If the receiving device is expecting 96kHz data it will demultiplex the two tracks into one and give it the correct track number. If not it will treat them as two separate tracks and give them inappropriate numbers. When you work with the analog I/O everything is handled internally and you don't notice. It is when you are transferring digitally via ADAT,FirePort or Ethernet that this becomes an issue.

In any case, let us know how you make out.
 
Last edited:
Soundbyte said:
Yes I know, but the same rules apply because that is the way the tracks are stored on the drive. If the receiving device is expecting 96kHz data it will demultiplex the two tracks into one and give it the correct track number. If not it will treat them as two separate tracks and give them inappropriate numbers. When you work with the analog I/O everything is handled internally and you don't notice. It is when you are transferring digitally via ADAT,FirePort or Ethernet that this becomes an issue.

In any case, let us know how you make out.
Click to expand...

This sucks. Why doesn't the manual explain this clearly? It only mentions this problem with ADAT at high sample rates. Apparently the high sample rate is best used with a digital mixer that can demultiplex, or an analog mixer for mixdown. I guess I'll call Alesis to confirm this.
 
I talked to Alesis tech support and found out that I'm not going nuts after all! It's a known issue with the software and they said that the update will be posted by the end of the month. We'll see. The secret is to select one file at a time for exporting. The duplication of the tracks happens when I select more than one track to export. I guess that the software combines the duplexed tracks into a single file when transfering through the Fireport, but gets confused when more than one track is selected for exporting, therefore it doesn't combine the duplexed tracks. The wave forms now appear as they should in my DAW software. And it even sounds soooo much better. WHEW!!!!
 
Parlor Music said:
I talked to Alesis tech support and found out that I'm not going nuts after all! It's a known issue with the software and they said that the update will be posted by the end of the month.
Click to expand...

Just curious: is it an umdate of the computer software or the hd24 firmware? If it's the computer software, I hope they have added a feature to extract whole projects (or a couple of songs) in one go, that would save up on some time not having to run in and out of the control room all the time when I could have a lunch break or something instead....
 
tgs said:
Just curious: is it an umdate of the computer software or the hd24 firmware? If it's the computer software, I hope they have added a feature to extract whole projects (or a couple of songs) in one go, that would save up on some time not having to run in and out of the control room all the time when I could have a lunch break or something instead....
Click to expand...
Good question. They didn't say specifically.
 
Glad to hear things are starting to get sorted out for you. There's nothing more aggravating than computer bugs but at least you've got a work-around solution until the fix is published.
 
You must log in or register to reply here.
Back
Top