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Author Topic: Using a JSD60 in a Drive In Lindsay Morris Expert Film Handler Posts: 233 From: Darlington, WA, Australia Registered: Sep 2002 posted 10-11-2016 07:46 PM                     I currently do "first in" mtce at a small community run DI where a JSD60 is installed along with a NEC 1600. From what I understand from the installer the JSD 60 when in DI mode the output levels to the ramp speaker amps is mono & what goes to the FM TX is L & R Stereo at a FIXED level. The front mounted volume control has NO effect on those 2 sound streams, It seems as though somehow this JSD60 has slipped into normal theatre mode as the volume CAN be varied going to the ramp amps or the FM TX by means of the front mounted volume control. I have read the manual from cover to cover & it mentions how it would function differently in DI mode but nowhere can I find HOW that is done. Any drive in users here that also use a JSD60 that can point me to where I might find that bit of info. I am NOT able to view any control screens on the JSD60 as the DI is some 240kms away. It seems that the problem is that loud or heavily bassy passages send the FM TX into horrible overload and the operators were able to turn the volume down by means of the front mounted volume control knob as a short term fix. But if they forget next screening the same old crappy sound blares forth once again until somebody complains  |  IP: Logged Harold Hallikainen Jedi Master Film Handler Posts: 906 From: Denver, CO, USA Registered: Aug 2009 posted 10-11-2016 11:28 PM                        See page 36 at http://ftp.uslinc.com/ftp/Products/JSD-60/Documents/Manual/JSD-60%20User%20Manual%20160406.pdf for information on selecting drive in mode through the gui. The gui can connect using usb or ethernet. You may be able to remotely access a local computer using Team Viewer to remotely run the gui. Also see page 85. If you hold down nonsync and mic during power up, the jsd will load config from the sd card IF it was saved during system config. Good luck! Harold  |  IP: Logged Lindsay Morris Expert Film Handler Posts: 233 From: Darlington, WA, Australia Registered: Sep 2002 posted 10-12-2016 01:05 AM                     Harold, Thanks for that...that download has some 30 more pages than the version I have at hand so now about to print that out & start reading all over again. Not able to remote in at all...I used to use Teamviewer to get access to my past outdoor venue but nothing like that in the setup at this DI. Its is in the sticks... so comms are rather iffy at best. Have you had any experience using this processor in a DI situation as I am curious as to how one can overcome the rather wide dynamic range available on DCP's as compared to film and whether or not a Limiting Amp in the chain before the FM TX input might help control things better. There were always limiting amps in the audio chain on AM transmitters but I have had very little exposure to how a FM unit handles wide dynamic ranges. What the operators are telling me is that the sound gets "scratchy or crackly" which is not a lot to go on & every time I have been there there has been NO DCP available to play only N/S stuff which sounds fine.  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 10-12-2016 02:21 AM                     I would certainly use a dynamic compressor for a drive in transmitter. Harold, wouldn't that be a nice-to-have DSP option for the JSD60? - Carsten  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 10-12-2016 03:27 AM                       I did a 4k Barco 32B in a DI in Dodge City using the JSD 60. Very good results using the snack bar output as well as an output to a Broadcast Warehouse Tx. Also grabbed an output for rows of speakers still in use. Works very well but yes, it needs a limiter. I sent a Smart afterburner which does the limiting but don't think it ever got hooked up despite I send a wiring harness while the install was still fresh in my mind. There are a few of those laying around in US booths. JSD 60 is a very nice unit and very affordable.  |  IP: Logged Lindsay Morris Expert Film Handler Posts: 233 From: Darlington, WA, Australia Registered: Sep 2002 posted 10-12-2016 05:29 AM                     Thanks Sam & Crasten, Only limiters I can seem to find down here are rather expensive..like $5K for single channel job...look more like a broadcast type unit though. I have a single channel unit lying about the workshop but have never seen a mate to it..I think it may have been made in Australia & did once run at a long since gone DI. No name badge on it & I have never powered it up. There is a dual channel limiter/compressor available locally but has a myriad of knobs just inviting some clown to have a fiddle & screw things up yet again. Costs around $400 AU. Any suggestions for a simple twin channel limiter in USA that we could source that's not overly expensive??.  |  IP: Logged Tim Sherman Expert Film Handler Posts: 125 From: North Ridgeville, OH, USA Registered: Aug 2000 posted 10-12-2016 09:42 AM                        I run my Jsd-60 in 5.1 mode at my drive-in and i manually changed the downmix settings to closely mimic the default drive-in mode downmix. The main thing I have noticed is that the factory default downmix is to high on the subwoofer channel. I prefer this mode of operation because it makes the front fader knob contol all channels instead of just the Snack Bar channel. This is important especially if you are running alternate content. Also it makes the display show all 8 channels, a great diagnostic tool in my opinion. Without being able to remote in to that theatre not really easy to modify the settings or find out how it is set up right now. I have a 6 band compressor/limiter on each screen but with the settings i'm running I no longer use them and never over modulate my transmitter. What transmitter is the drive-in you speak of running? The BW Broadcast tx5 is a great transmitter with a built in limiter and processing.  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 10-12-2016 11:02 AM                       I never got to play with the limiter functions of the BW and the owner is a bit intimidated which is why we went with the Smart. I was never a Smart fan but this device is right for the job. I have access to a few of the Afterburners if Lindsay is interested.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 10-12-2016 01:06 PM                     The limiter function on the BW works adaquately. One has to remember that these are all FCC approved high quality transmitters and they have to meet minimum FCC specs to get approval. Many small and many independent FM radio stations in smaller markets use these BW transmitters as back up and the larger units as their primary transmitter. They are VERY easy to service if they go down, and I have had one go down in more way than one. I never used a Smart Afterburner but I think Gord McLeod has used them. Mark  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 10-12-2016 05:01 PM                     Lindsay - you should be able to get decent stereo compressors (link mode) for less than 200US$. Note, a limiter will help to prevent overloading the TX, but not against the high dynamic range of modern digital soundmixes. For this, you need a compressor. Some devices offer both, even the cheaper ones. Samson S-Com, dbx 266, etc. Check out the simple Rolls SL 33b! Yes, many have too many knobs, they need to be adjusted initially on location, but there are protection rack panels available that will prevent unauthorized access. - Carsten  |  IP: Logged Harold Hallikainen Jedi Master Film Handler Posts: 906 From: Denver, CO, USA Registered: Aug 2009 posted 10-12-2016 10:30 PM                        Thanks for the list of compressors, Carsten! We saw prices like that when we were designing the JSD-60 and also that some transmitters have a compressor built in. We could not justify the cost of coding a compressor into the DSP for so few users. As has been noted, we tried to make the JSD-60 as flexible as possible. The entire configuration is saved as a text file that is run through a command processor (the same one that handles automation) on start up. You can see the configuration file with a web browser at /ConfigFlash.html. This same file is saved by the GUI and to the SD card. You can edit the file to make all sorts of non-standard things happen. The GUI attempts to give you access to these commands in a user-friendly way (for example, setting the mixer coefficients). I did the microcontroller work on the JSD-80, JSD-100, and JSD-60. I learned (I think) as I went along. I REALLY like using text config files (like in the JSD-60) since we can add features without corrupting a binary blob. Harold  |  IP: Logged Lindsay Morris Expert Film Handler Posts: 233 From: Darlington, WA, Australia Registered: Sep 2002 posted 10-13-2016 05:45 AM                     The transmitter is a cheapy available widely here in OZ & is called a SainSonic AX058. Runs normally at 0.1W & can be set to 0.5W on the Hi setting. The block diagram for it shows a limiter inbuilt so maybe there is something else messing things up. Will know more when I get up there next week. Coverage on 0.5W was around 7kms radius from the DI field...back on 0.1W the signal started to mute at about 1km radius. Good strong signal all around the actual DI field. The blurb also states that it is FCC approved under part 15 rules so no licence is needed. Thanks for the responses. They have given me much to think about & went hunting for a Compressor/Limiter & found a unit intended for band muso use that looks OK & costs under $200 so IF we have to go that way it is economically doable for the group. Interesting that IF one gets the JSD60 settings just right that a Compressor Limiter is not needed will look at what Tim has done & see if I can replicate that. There is NO sub woofer installed there though. They DO run occasional alternate content so possibly having the Fader operational on all thruputs might also be a good move as they had grizzled about low levels on alternate stuff. First check will be as to exactly what settings the JSD60 currently has & then go from there. Will keep yah posted.  |  IP: Logged Dave Macaulay Film God Posts: 2321 From: Toronto, Canada Registered: Apr 2001 posted 10-13-2016 08:35 AM                     A subwoofer at a drive-in sounds like an interesting challenge... neighbors might be annoyed though. The sub signal is still on the DCP though, and if it's included in your L/R transmitter mix it could cause overmod on explosions or music. A compressor/limiter is a good addition to the transmitter signal path. Unfortunately the transmitter and compressor tend to have knobs that invite "improvement" adjustments. Setting them properly seems to be beyond the skill of site staff. The resulting sound quality can be far worse than having occasional overmod.  |  IP: Logged Cameron Glendinning Jedi Master Film Handler Posts: 845 From: West Ryde, Sydney, NSW Australia Registered: Dec 2005 posted 10-14-2016 07:55 PM                     I have a JSD60 set in Drive in mode, which I use mostly for outdoor cinema screenings with inflatable screens. To get the sound to the audience from the back of the crowd, I have several ways to get the signal to the p.a system using a long run of cat 5 cable, a Sony radio mic system, silent cinema option /up to 330 wireless headsets and have just set up over the last few days a new custom manufactured FM transmitter, as recommended and used buy the Luna Drive In. Tonights Park screening of Finding Dory is to be the first audience screening via fm, over the last few days I have had the JSD60 directly outputting into the cannon inputs of the low power FM transmitter with crystal clear results. Sub woofer is part of the mix displayed and no distortion via FM or Sony professional radio mic or silent disco transmitters has yet been noticed. Volume knob has no effect on output.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 10-14-2016 09:22 PM                     Drive In subwoofers were easy when Intersonics was still in buisness. We rattled glass 25 to 30 stories up in apartment buildings a half block away with this line up. People complained and we had to turn them down a bit. That's a 70' wide screen by the way. Mark  |  IP: Logged

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