IA76 Posted June 14, 2011 Share Posted June 14, 2011 Hi Is it possible to feed sound from a laptop to XLR socket where a phantom powered dynamic mic is usually powered via a DI box? laptop-->DI box-->mic socket We want to play sound from a powerpoint on our PA system and it would save on a lot of cabling if the above is ok to do and it won't damage the laptop. Link to comment Share on other sites More sharing options...
SimonTheSoundMan Posted June 14, 2011 Share Posted June 14, 2011 Zero damage to the laptop. This is the best way to wire it up. Link to comment Share on other sites More sharing options...
azlan Posted June 14, 2011 Share Posted June 14, 2011 yes that should work fine, I can't see how that would damage the laptop. Link to comment Share on other sites More sharing options...
Mixermend Posted June 14, 2011 Share Posted June 14, 2011 You can certainly feed the line output, or headphone output signal into a DI Box and then on to the PA Mixer. Don't ever make up direct cables to make the connection - as there are dangers to the laptop from the inadvertent application of phantom power - so some form of barrier is essential. This can be provided by almost any DI Box, but you might want to consider an isolation transformer device - as this can also prevent power supply noises from the laptop being passed to the mixer. Never a problem when run on the internal battery! Link to comment Share on other sites More sharing options...
Simon Lewis Posted June 14, 2011 Share Posted June 14, 2011 .....a phantom powered dynamic mic The DI will isolate the laptop, but I'm not aware of dynamic mics needing phantom - unless you have some esoteric ENG mic? Link to comment Share on other sites More sharing options...
chelgrian Posted June 14, 2011 Share Posted June 14, 2011 Is it possible to feed sound from a laptop to XLR socket where a phantom powered dynamic mic is usually powered via a DI box? laptop-->DI box-->mic socket We want to play sound from a powerpoint on our PA system and it would save on a lot of cabling if the above is ok to do and it won't damage the laptop. Dynamic mics don't need power, condensers generally do although mostly these days to power the integrated pre-amp rather than to polarise the capsule as most things sold as condensers are actually electret condensers. Having said that your desk may only have global phantom power. In any case as long as the inputs on you desk have sufficient gain range to be able to cope with with both line and mic level signals then you going laptop->DI->XLR input will be fine. You will not damage the laptop (1) because either you are using a passive DI box with has no electrical connection between the input and the output as it's effectively a transformer. Or you are using a active DI box which probably requires phantom to power itself supplied from the balanced side anyway. The other option is something like http://www.artproaudio.com/products.asp?id=77&cat=13&type=90 which has some more active components inside it and gives you control of the output level. Instead of using PowerPoint directly I'd recommend you use something like Screen Monkey http://www.screenmonkey.co.uk/ (1) This advice comes with no warranty and it's always possible for someone to have an insane bit of kit which causes +48v to appear on the unbalanced side via mis-design or just plain stupidity. Link to comment Share on other sites More sharing options...
billy jim Posted June 14, 2011 Share Posted June 14, 2011 To piggyback onto this, should the same kind of thing be done for, say, an iPod? Link to comment Share on other sites More sharing options...
SimonTheSoundMan Posted June 14, 2011 Share Posted June 14, 2011 Yes. Line/headphone level is pretty inefficient due to their high impedance. Also isolation, making the connection balanced is a bonus advantage. You're more likely to blow your laptop or iPod by running at line level running over long distances as it puts the small amps in them under more strain than they are designed to handle. Link to comment Share on other sites More sharing options...
billy jim Posted June 14, 2011 Share Posted June 14, 2011 But running *a short distance* into an unbalanced stereo input on jacks would generally be alright? Been wondering it for ages, just never actually asked the question... E2A clarification on distance Link to comment Share on other sites More sharing options...
gleek96 Posted June 14, 2011 Share Posted June 14, 2011 This is the system we have installed in my school and it has been fine. You just have to make sure that if you wire it from the sound output and the back of the computer, that there are no other things plugged into the output at the front of the computer as this will overide your DI. BOX and so you will get no sound. That is the only thing we have to check whenever using sound from our computer. Link to comment Share on other sites More sharing options...
IA76 Posted June 14, 2011 Author Share Posted June 14, 2011 Thanks for the quick replies and I did mean condensor mic and not dynamic! Link to comment Share on other sites More sharing options...
azlan Posted June 14, 2011 Share Posted June 14, 2011 But running *a short distance* into an unbalanced stereo input on jacks would generally be alright? Been wondering it for ages, just never actually asked the question... E2A clarification on distance that should work, we use the 2track input on our desk at our students union to hook up laptops etc. without a DI box, and get acceptable results, and I have run my laptop directly into my spirit folio SX in the past, I would guess it depends if your desk is designed to take unbalanced inputs or not. Link to comment Share on other sites More sharing options...
casino_man_dan Posted June 15, 2011 Share Posted June 15, 2011 does anyone know of any small usb/firewire audio interfaces with physical XLR outputs to do this instead. I use a laptops for shows/conferences and HATE rca/phono cable...even if you convert to XLR with adaptor, it's still going to be the weak link...especially with that minijack precariously poking out the headphone socket (which never gives good audio at best of times) googled a bit but can't seem to find any portable 2ch out with XLR's any suggestions?d Link to comment Share on other sites More sharing options...
Bobbsy Posted June 15, 2011 Share Posted June 15, 2011 I can't think of any with XLR outputs but there are quite a few with balanced out on quarter inch TRS connectors. Is it the actual XLR you're worried about or just getting it balanced? Link to comment Share on other sites More sharing options...
david.elsbury Posted June 15, 2011 Share Posted June 15, 2011 CPC do a usb soundcard straight to XLR out. http://cpc.farnell.com/_/av17492/usb-audio-interface-usb-to-2-2/dp/AV17492?in_merch=Products%20From%20This%20Range&MER=e-bb45-00001003 Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.