Andrew C Posted May 2, 2009 Share Posted May 2, 2009 Right, so we bought one, tried it and decided that the Marantz would work for us. This week sees the start of the season, and using four different recorders, several different cards, and 2 PCs, two different teachers got partially corrupt recordings. The recorders are set to PCM-16, 48k WAV. We're doing multiple 15 min recordings of spoken exams, most are fine (60+) today, but 4 have broken up at the end. Two of the tracks were reported as corrupt by Windoze, but chkdsk enabled me to copy them off to the PC and load them into Audition. The last minute or so has blocky, broken audio. The cards are Sandisk SDHC 4Gb. Any thoughts? Link to comment Share on other sites More sharing options...
mervaka Posted May 2, 2009 Share Posted May 2, 2009 oh dear :s how do you mean 'broken up' and 'broken'? Link to comment Share on other sites More sharing options...
smalljoshua Posted May 2, 2009 Share Posted May 2, 2009 Could it be the use of such large cards? There are some documented problems with the SDHC Cards out there. I don't like to use more than 2GB SD Cards as it avoids any possible compatibility issues with the lack of support the SDHC format. Most if not all 4GB cards out there are SDHC. Hence my 2GB preference. Josh Link to comment Share on other sites More sharing options...
Andrew C Posted May 2, 2009 Share Posted May 2, 2009 The instructions refer specifically to 4Gb SDHC cards giving 5 3/4 hours at full quality. What they don't mention, and I have only discovered myself today, is that there are different "speed" cards. Although the slower ones (Class2) should be OK, it looks like this might be my problem. I've ordered some Class6, I'll see what happens with them. It won't help with Tuesday's exams; I'll turn the quality down for them. How to describe "broken, blocky" sou ..... nd. It's a bi. ....... . tlikethisbut the le....... vels go a ...... ll ....overtheplacetoo. Think Kryten from Red Dwarf when he sticks. Sme...Smeeeeeeg Hhhhhheeeeaaaaad! Link to comment Share on other sites More sharing options...
mervaka Posted May 2, 2009 Share Posted May 2, 2009 it does indeed sound like a buffer overrun. FWIW, if mp3s submissions are acceptable, their bitrate will be much lower for recording onto SD cards. it's just a shame it the marantz doesnt offer a 22050Hz sample rate :( EDIT: hang on a minute. I dont think that's definitely the case. 2 channels of 48k 16 bit audio comes in at 0.18MB/s, and a class 2 SD card can write at 2MB/s.. Link to comment Share on other sites More sharing options...
Andrew C Posted May 2, 2009 Share Posted May 2, 2009 it does indeed sound like a buffer overrun. FWIW, if mp3s submissions are acceptable, their bitrate will be much lower for recording onto SD cards. it's just a shame it the marantz doesnt offer a 22050Hz sample rate :( EDIT: hang on a minute. I dont think that's definitely the case. 2 channels of 48k 16 bit audio comes in at 0.18MB/s, and a class 2 SD card can write at 2MB/s..They will accept MP3s. I want to keep them as .wav as I need to boost the level as whatever I do with the mics it is too low for comfort. I can easily drop to 44.1, or if it is still a problem before the faster cards arrive, MP3. After a level boost in Audition, they all get saved as MP3. I did the calculation myself; I began to doubt my decimal places or whether bits and bytes were getting confused! Having one or two "damaged" isn't too traumatic. Each teacher/examiner will choose a representative 'good', 'middle', and 'weak' candidate. I'll just have to persuade them to pick kids who don't talk like Kryten! Link to comment Share on other sites More sharing options...
mervaka Posted May 2, 2009 Share Posted May 2, 2009 could you swap in a more sensitive mic? EDIT: or a compressor or some other gain device? Link to comment Share on other sites More sharing options...
Killyp Posted May 2, 2009 Share Posted May 2, 2009 I think you mean Red Book. B-)So, how did your music tech exam go? :( I don't do music tech ;) Link to comment Share on other sites More sharing options...
the kid Posted May 2, 2009 Share Posted May 2, 2009 I pointed out IT head this direction because a few weeks ago they were stuck with recording a oral exam, they had to load a new piece of software (apparently it was a preset instruction list) the examiner had never REALLY used before + microphones. After much faffing we converted XLR to jack to phono to minijack to go to the pc. But the examiner gave up and just used .... tape. Link to comment Share on other sites More sharing options...
Andrew C Posted May 4, 2009 Share Posted May 4, 2009 There was NO WAY that I was going to use a PC directly. Ludites one and all! Link to comment Share on other sites More sharing options...
TomHoward Posted May 4, 2009 Share Posted May 4, 2009 Have you tried formatting the SD cards in the Marantz before you start, rather than formatting them on a PC or pre-formatted out the box? I used to use one of these and I remember it was a bit funny about formatting - but so many other things are the same. Link to comment Share on other sites More sharing options...
Andrew C Posted May 4, 2009 Share Posted May 4, 2009 Have you tried formatting the SD cards in the Marantz before you start,No, not tried that; although I don't see why only 10% would fail if it was a formatting issue. Still, worth a shot! Link to comment Share on other sites More sharing options...
TomHoward Posted May 4, 2009 Share Posted May 4, 2009 Have you tried formatting the SD cards in the Marantz before you start,No, not tried that; although I don't see why only 10% would fail if it was a formatting issue. Still, worth a shot!I've had all kinds of problems with anomalies from filesystems - I've got an LS9 that won't read pendrives that have been formatted on a PC, a Bullfrog that won't write to disks formatted elsewhere, and the ms has one of those Marantz that wouldn't record until we'd formatted the cards in it rather than the PC. It's just become a habit to format things in whatever you're using them in for me, because the PC will usually still read them, but sometimes they're using FAT16 etc. Link to comment Share on other sites More sharing options...
Andrew C Posted May 5, 2009 Share Posted May 5, 2009 Better today. Reduced the bit rate, and cards formatted on the machines; only one damaged recording. ;) Ahh well, wait for the faster cards to arrive with fingers crossed! Link to comment Share on other sites More sharing options...
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