ojc123 Posted July 22, 2012 Share Posted July 22, 2012 I've been asked to install the redundant system from the Hall into the Gym. Easy enough. The speakers have Eminence APT80 compression drivers. They are quite good but "They don't like it up 'em." Specifically they don't like it if the amp is on before the mixer. This is fine when dealing with people who can be trained; I'm dealing with PE teachers (and a Dance Teacher who still turns up with Cassettes!). I have thought about sequential start PDUs like this or this. Would those help? They are a bit pricier than a 4-Way from Poundland but if they save me replacing the drivers or diaphragms every week then it'll be worth it. I have available a Behringer MDX-4600 which I considered putting between the mixer and the amp. I'd expect to have a high compression ratio and a very quick attack and a 10ms-ish decay (just guesswork). That's to prevent problems from plugging in whatever portable music device or random laptop the kids turn up with. I've never used a compressor in this way and I'm not sure if it's a good idea. I'm only dealing with two stereo input devices so the compressor could go between the devices and the mixer if we thought it better. I may be barking up the wrong tree (or just barking) but I'm sure I'll soon be told if that's the case. I ask the combined wisdom of the Blue Room for beyond idiot-proof solutions to this problem. I need to have a system where the speakers have some protection despite the best efforts of four PE teachers. Budget is in the order of £200 for hardware for this purpose so keep it simple. I'll try to lock up as much as possible so they only have access to the minimum necessary to work the system.Thanks in advance. Link to comment Share on other sites More sharing options...
Matt Riley Posted July 22, 2012 Share Posted July 22, 2012 In a similar vein, you may find that using a time delay relay on the amps would also fix the start up issue for less money than the solutions mentioned. Another potential source of issues could be that the action of plugging/unplugging the minijack isn't helping either? Link to comment Share on other sites More sharing options...
paulears Posted July 22, 2012 Share Posted July 22, 2012 Will a compressor actually cure the problem - the problem if I've understood you correctly will be when they power it up, and then stick the plug into the CD player or other gadget and it's the pop that damages the system - will the compressor stop this? I'm not certain it will. Link to comment Share on other sites More sharing options...
ojc123 Posted July 22, 2012 Author Share Posted July 22, 2012 The minijack pop is one of the problems. I do not know if a compressor will stop that. I was sort of hoping people here might know. The switch on and off is my other problem. The time delay PDUs I linked to solve the switch on but I've just realised they don't solve the switch off. It may be there is no technology which provides a solution. I may have to attempt to train the PE teachers. All suggestions welcome. I'm looking into the time delay relay; thanks for the suggestion. Link to comment Share on other sites More sharing options...
timd Posted July 22, 2012 Share Posted July 22, 2012 Given that latency really isn't an issue here, you could use a digital compressor which would catch the plug-in pops. The Behringer UltraDyne springs to mind, but if you want them to last you need to hack a hole in the box and fit some cooling fans! Link to comment Share on other sites More sharing options...
djw1981 Posted July 22, 2012 Share Posted July 22, 2012 The minijack pop is one of the problems. I do not know if a compressor will stop that. I was sort of hoping people here might know. The switch on and off is my other problem. The time delay PDUs I linked to solve the switch on but I've just realised they don't solve the switch off. It may be there is no technology which provides a solution. I may have to attempt to train the PE teachers. All suggestions welcome. I'm looking into the time delay relay; thanks for the suggestion.Replacement drivers due to misuse could come from PE budget not tech! tHta might focus minds Link to comment Share on other sites More sharing options...
lampygirl Posted July 22, 2012 Share Posted July 22, 2012 For your switch on and switch off problems, I've seen this system used a few times in clubs and the like http://www.canford.co.uk/Products/42-661_EMO-MASTER-SWITCHER-UNIT-CM6 It does both the on and off sequence for you, rather than just the on. Obviously doesn't stop DJs turning the mixer off (or teachers in your case), but means the socket it gets plugged into can get switched off in the correct order, though might take a bit more of an electrical install than you want? L Link to comment Share on other sites More sharing options...
david.elsbury Posted July 22, 2012 Share Posted July 22, 2012 Think a digital processor is the way to go, I recall reading somewhere that because it delays the input it can properly react to transients etc, whereas an analog processor tries to do it in real time, thereby not being as effective. Just don't whatever you do get a DBX Driverack PA (version one), they have a habit of destroying drivers on power-up... (Driverack PA+ doesn't do this) David Link to comment Share on other sites More sharing options...
ramdram Posted July 22, 2012 Share Posted July 22, 2012 We had a "tech manager" who had plugged the amp, desk and CD player (in this instance) into the same four way and thence into a 13A socket. The on/off switches on the kit were not switched off individually. He simply switched on all the kit at the same instant and relied, presumably, on the "slow start" circuitry in the amp to self test for shorts...did it all season and never had any thumps or issues with the kit. None of us were convinced he knew what he was about and he just got away with it. Link to comment Share on other sites More sharing options...
ojc123 Posted July 23, 2012 Author Share Posted July 23, 2012 The minijack pop is one of the problems. I do not know if a compressor will stop that. I was sort of hoping people here might know. The switch on and off is my other problem. The time delay PDUs I linked to solve the switch on but I've just realised they don't solve the switch off. It may be there is no technology which provides a solution. I may have to attempt to train the PE teachers. All suggestions welcome.I'm looking into the time delay relay; thanks for the suggestion.Replacement drivers due to misuse could come from PE budget not tech! tHta might focus mindsdjw1981 Focus minds? PE Teachers. I doubt it. Certainly that's where the money will come from though. lampygirl The switcher looks great but is well beyond budget. Thanks though. The Digital LMS might help. I'll investigate. Ramdram Getting away with it would be good. I'll try it with my Class-D speakers and see what happens. I can afford to fry the £5 'Professional' tweeter in the interests of Science. Thanks all. Link to comment Share on other sites More sharing options...
david.elsbury Posted July 23, 2012 Share Posted July 23, 2012 A bit left-field, but how long are classes? 45 mins, an hour? Could you set up some sort of sequencer that at the press of one button, powers up the kit in sequence for a specified time (say 1 hour) and then at the end of that time period, powers down in sequence again? Pressing the button in the middle of the period would reset the timer to the start of the sequence. That said, thinking over that it doesn't solve the "minijack pop" problem for you however. Hmm, back to the drawing board :)David Link to comment Share on other sites More sharing options...
Matt Riley Posted July 23, 2012 Share Posted July 23, 2012 If the price was right, you could use a time delay off relay like this one to delay the off on the mixing desk and cd player etc in conjunction with a time delay on relay for the amp. Link to comment Share on other sites More sharing options...
cedd Posted July 23, 2012 Share Posted July 23, 2012 The big issue people don't seem to be able to find an answer for here is the mp3/laptop connection problem. It's a real shame Neutrik don't make one of their silent jack connectors in 3.5mm, because that'd really help you out. Thinking WAY outside the box here, could you not build some type of enclosure for the laptop/mp3 player/iPod's "protection" - from footballs and the like. A microswitch when the door's open sticks a whopping attenuator across the audio to the amp, or maybe even mutes it completely. That way the device has to be used when the door's shut in order to get reasonable volume out of it - if they can unplug it while the door's shut then they've got some skills! You'd need to provide volume controls outside of the enclosure so they can make adjustments once the level comes back up when the door's shut. All kind of depends how often they want access to the device to change tracks. It's not ideal and certainly not that user friendly, but it does solve your jack plug issues. Link to comment Share on other sites More sharing options...
vlfaudio Posted July 23, 2012 Share Posted July 23, 2012 For £200 you could probably put in some higher rated tweeters... Link to comment Share on other sites More sharing options...
jamesperrett Posted July 23, 2012 Share Posted July 23, 2012 For £200 you could probably put in some higher rated tweeters... Or a 12V lamp / Polyfuse wired in series with the tweeters. James. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.