media gurus, can you help?

Discussion in 'Buying Tips and Advice' started by typewriterchimp, Apr 21, 2007.

  1. typewriterchimp macrumors member

    Sep 30, 2005
    Hi everyone,

    I'm using a g4 ibook (final revision) with 1.33ghz g4 and 512 megabytes of ram. I'm working on a project currently and I'm wondering what kind of extra hardware I would need to buy in order to meet the project's needs. Basically, I need to be able to play multiple .wav files at the same time, and I need each .wav file to output through a different external "channel" (I'm not sure if this is the right terminology). Ideally, for example, my ibook would have 3 or 4 headphone jacks, each capable of playing the output of a different .wav file on its own. Or, alternatively, it would kind of be like duct taping a stack of ipods together.

    What kind of equipment would allow me (via usb?) to do something like this? Does anyone have any experience using a piece of hardware like this, and how well does it work with mac?

    any advice would be greatly appreciated. I would do a forum search, but as you might be able to tell, I'm not even sure what to call such a device (if it even exists).

    many thanks

  2. faintember macrumors 65816


    Jun 6, 2005
    the ruins of the Cherokee nation
    First, what program are you using to play the audio files back from?

    Second, are the audio files mono or stereo?

    Third, you are looking for an audio interface. These come in USB and Firewire flavors and can range widely in price. To figure out which would be best for you, how often do you plan on doing this type of operation? How much CPU do you have left after the playback is going? Are you planning on using non-audio USB or FW devices during the playback? And what is your price range (this might be the most important).

    Fourth, any info about the project (that you don't mind sharing) might help us make better recommendations as well.
  3. typewriterchimp thread starter macrumors member

    Sep 30, 2005
    thanks for the detailed questions. here's my best answers:

    1)audacity or quicktime will be used to play back the audio files.

    2)the audio files are in stereo, but using audacity, could be converted to mono if needed (prefer to keep them in stereo)

    3)this is a studio arts project in an mfa program that involves multiple listening stations. each listening station has a different file looping continuously--the user need not have control at the listening station. I will be doing many projects like this in the future, using this feature at least 3 times per semester and at times in gallery presentations. the sound files I use are nothing complicated right now, so perhaps audio quality isn't a huge concern, although as mentioned above, stereo makes it sound better.

    Using quicktime player, I use about 40% of my cpu playing back 4 stereo mp3s simultaneously. I do not plan on using any external devices other than the interface (thanks very much for the information, by the way).

    and finally, price range: is 100 dollars a good target?

    thanks much

  4. faintember macrumors 65816


    Jun 6, 2005
    the ruins of the Cherokee nation
    Ok, don't want to burst your bubble, but what you want to do is a bit complex, and is not do-able for $100.

    First you need 4 stereo channels of discrete audio. Audacity will not playback multiple audio channels, and it hates most USB or FW audio interfaces (it gives error messages, but there is a quasi-workaround with Soundflower (long story)). Quicktime won't do what you want as well. You can play multiple files back in quicktime, but there is not a way to send them to multiple outputs as would be needed. Either way, even if you can work out the software issue you will run into a hardware issue...

    The other part is a 4-output audio card is easily over $100.

    Even if there was a audio card in your price range to do what you want, most are not set up with stereo outputs. The audio card would then need 8 outputs, as each output is one audio channel (4 tracks with 2 channels each). Then they are the cables you would need.

    But back to your project: Are the listening stations going to have headphones or speakers?

    If speakers, well you need to make some friends in the music department, either with composers that work with electronic composition or with the audio recording/engineering students. If these students are around, and willing, they can pretty much do whatever you want, provided the school has the materials. Note, these students are typically very busy and are often asked to do things like this, so don't be surprised if they say no (i know, I was one of them!).

    If headphones I would recommend that you do it the low-tech way: Burn each audio file to a different CD, find the number of CD players that you need (that have a repeat feature) and run your headphones from the players. The nice thing is this can be a mix of 1 portable CD player, 1 iPod, 1 shelf-sized CD player, etc. (I assume you are doing headphones, since you mention gallery, unless you are doing a audio-installation art project).

    Best bet: Pawn Shops. Find some component CD players for cheap and do it the lo-tech way. Most component players have headphone outputs and repeat settings. They can also be stacked up neatly. If you can't find players for cheap bug family and friends to borrow their players, their iPods, etc. Basically if it plays a audio file/CD and can have headphones plugged in, you can use it.

    The good news is you already have your computer as one source, so just 3 more to go.
    There may be some other way to do it, but I am not seeing it. This coming from a electronic music composer who ran electronics for two national music conferences and as part of his assistantship.
  5. typewriterchimp thread starter macrumors member

    Sep 30, 2005
    thanks for the wealth of info and the suggestions.

    I have a few mp3 players and cd players which may end up as the equipment for now. but for the longterm, I might as well ask (since you probably know):

    what would be the equipment and software (assuming a larger budget of 200-300 dollars) needed to actually accomplish what you described: 4 independent audio tracks playing out to 4 sets of headphones. If this becomes a more serious theme in the work I do, it might be worth planning for the long haul.

    Hate to bug you, and thanks very much for the practical advice and expertise.


  6. faintember macrumors 65816


    Jun 6, 2005
    the ruins of the Cherokee nation
    It's no problem at all.

    For software Logic Express, Cubase SE (the low end one). Basically you need a program that can spit out 4 stereo audio tracks. Cubase SE is $75 with the educational discount. It should playback 8-channels, as LE does, and it is the "bundled free with certain interfaces" software.

    For hardware you need an audio interface and a headphone amp. The issue here is you need 8 channels of audio out, so that basically means a FW interface. The cheapest you will get is the M-Audio Firewire 410 for $299, however you might get lucky and find a "demo" unit for slightly less. The nice thing is this unit gives you 2 headphone outputs, 8- 1/4" outputs and some other stuff you will probably never need. Next stop is a headphone amp. This is one option: Samson S-Phone for $150. This will give you your 4 stereo in/out (with even more outputs still available). The thing here is each stereo input (located on the front panel as "aux in") is one 1/4" female, so you need to combine two mono 1/4" cables from the audio interface into one male 1/4". So you need four of these, which will go into the "aux in" on the headphone amp. That should convert the 2 mono 1/4" lines into one 1/4" stereo line. Or just go with a TRS (stereo) to TS (mono) snake such as this and it should save a little bit of money.

    So you are looking at 75+300+150+20 (adapters)+30 (1/4 to 14 cable snake)=$575

    The audio chain would look like this:
    Computer>Audio Interface>1/4to1/4 snake>Y adapter>Headphone amp>Headphones

    Another option would be to eliminate the headphone amp, and do this:
    Computer>Audio Interface>1/4to1/4 snake>Y adapter>Headphones

    The tricky thing about the above setup is you will have to balance the audio for each set of headphones via software, you would need 4 1/4"female to female adapters (to connect the 1/4 TRS to the headphones). So, basically you will save $150 this way.

    Now, you may be able to save some money on a different headphone amp, or coming up with a software alternative. The nice thing is the audio interface is of pretty good quality and should last for a while (my masters uni. used two as part of their studio) and the headphone amp can accommodate up to 3 sets of headphones per "channel" for a total of 12 headphones. Hell, there may be a cheaper way to do this in general, but if you are serious about this type of deal, this is the way to go IMHO. The main thing that drives up the price for this is the 4 separate stereo channels, and I don't see a way around that issue.

    Now, for a future performance of something like we are discussing, you may want to venture into the electronic music composition students or the music engineering students, as with some time and planning, they might be more willing to help, and even loan some equipment.

    good luck!

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