using car/home audio equipment as a part of your rig?

Discussion in 'Amps and Cabs [BG]' started by Casey C., Jul 9, 2002.

  1. Casey C.

    Casey C.

    Sep 16, 2000
    Butler, PA, USA
    I know this question is asked alot, it should be in the FAQ IMO. My question is, can you use car or home audio components (such as speakers, amps, eqs, and so on) for guitar or bass? and can you use things used for bass or guitar (pedals, speakers, etc.) for car or home audio systems? I'm just curious.
  2. ldiezman


    Jul 11, 2001
    well.. i've been saying for sometime that I was going to build a cab equiped with a 12' dual voice coil "car" speaker and push it with a 700 watt amp with a built in crossover. i would call it my little thumper... use it as a feeling cab not really for sound.. I got my 410 to do that :)... but alas.. i haven't even done it yet
  3. bassmanjones


    Feb 23, 2002
    Boston, MA
    I know Anthony Jackson is known to use extremely hi fi home audio equipment (preamp/power amp) for that part of his rig. He has (or had rather, it got stolen) an FM acoustics preamp at $20k a pop and a power amp that I can't remember the brand of which is around $8k a pop.

    And some of you guys think you're tone nazis. ;)
  4. Golem II

    Golem II

    Jan 4, 2002
    Macon, GA, USA
    While we're in this ballpark:

    Just for kicks I tried plugging my bass into my Digidesign digi 001 (a cheap version of the Protools software for computer recording,) system today, and running the outputs through my poweramp into a speaker cab. I used the software plugins as tone controls, with 4-band parametric EQ and the software version of the Sansamp PSA-1. The results weren't half bad, though the sound had that "polite" and non-aggressive digital quality. It got me thinking: does anybody use their computer as an instrument rig or PA? If you had a laptop, or a rackmounted computer (I know they make rackmount kits for macs and flatscreen monitors, not so sure about PC's) so it'd be feasible (though pretty strange and impractical) to use your computer and software as an all-in-one mixer and FX processor. Of course, you'd get crucified by all the world's analog fans.
  5. Golem II

    Golem II

    Jan 4, 2002
    Macon, GA, USA
    would there be any way to shield the computer from this with a rackmount case or shell, or would that cost more money than it's worth?
  6. Ty McNeely

    Ty McNeely

    Mar 27, 2000
    Shouldn't be any need for shielding. If you sat the laptop on top of the cabinet it wouldn't hurt it. The plywood of the cab is thick enough to absorb that much magnetism so there's really no danger in it at all unless you just happen to sit it in the right spot.
  7. Golem II

    Golem II

    Jan 4, 2002
    Macon, GA, USA
    If you and Psycho are contradicting each other here, I think I'm gonna have to listen to Psycho. I don't think plywood can "absorb" a magnetic field. I've accidentally placed speakers near TV's and monitors before, and the magnets had an obvious effect on them. On the other hand, I pass within a hair's breadth of my computer whenever I carry my cabs out of the room, and there hasn't been any damage so far. I'm guessing as long as I didn't sit the computer or monitor on top of/next to the speakers it'd be alright.
  8. wood will not absorb magnetic fields... i think it may dampen them some but not enough... you can probably get computer parts or something to shield them (stuff like computer speaker casings or something)... but magnets will screw with a hard drive quicker than a jack rabbit on a hot date...

    have fun!
  9. geshel


    Oct 2, 2001
    Yep, what bassist4ever said. Wood don't mean nothin' to magnetic fields. :)

    The field isn't too strong however more than a foot or two away from the drivers. I'm not sure I'd risk a hard drive around one, though. Somebody somewhere online probably has experience with this sort of thing.
  10. Casey C.

    Casey C.

    Sep 16, 2000
    Butler, PA, USA
    hmm... what kind of tone would that give you? :confused:
  11. Casey C.

    Casey C.

    Sep 16, 2000
    Butler, PA, USA
    also, are cabs the same with both applications? I know that ported sub enclosures give you more bass and sealed enclosures give you more punch (car audio). How does this work with bass cabs? I know that bass cabs can push out alot of air and if there is no where for that air to go it will blow the speaker (right?). Thats why I ask.

    I've been playing for 3+ years and I still don't know these things...:p
  12. Jontom


    Mar 11, 2002
    New York
    Check what ohmage your amp is running at(2,4,8). Most car speakers are 4 ohms, while home audio/instrument speakers are usually 8.

  13. I really want to do this too - I've been having trouble deciding which type of amp to use, whether I should use a power amp, a PA amp, or something else, like maybe using a car amp - although I don't know how to switch the power from DC to AC.
  14. geshel


    Oct 2, 2001
    The magnetic field from a speaker won't do anything to harm RAM or your CPU (I don't think it would interfere with their operation, either). It also won't harm your hard drive - but it might screw up the data on it. :)

    As for car audio subs, they are

    1. designed for use in very small boxes, and therefore

    2. terribly inefficient (good ones are like 85 dB 1w/1m these days)

    3. because of this they are built to withstand loads of power, and also

    4. 4 or 2 ohms to get as much power out of the amp as possible (car audio amps, running from a 12-volt high-current power supply, have an easier time with low impedances than home-audio designs)

    5. they are designed knowing that, when the box is put in the car, there is *at least* a 20dB boost going on in the bass region due to the fact that a car is a small space and a couple 10" or 12" push enough air that the properties of sound at low frequencies is different (closer to pressurizing the whole car at once). Opening a window or two doesn't change this too much.

    So. . .take a good bass guitar cab (say a 4x10) that puts out 95 dB at 1w at 30Hz. A car audio sub (say a 15") in a proper sealed box will likely be at least -5dB at that frequency, so 80dB at 1w. To get to the same 95dB level requires 70x the power.
  15. And you can get 19 inch rackmount computers. Professional servers normally come in that shape
  16. geshel


    Oct 2, 2001
    A magnetic field doesn't induce a current unless a) it is changing, or b) the conductor is moving. I don't think the stray field from a speaker (speakers are designed to concentrate as much of the field as possible within the gap) is nearly strong enough or changing enough to have this effect.

    We have this image of speakers throwing powerful fields because they interfere with CRTs. But it doesn't take much of a field to make a single electron, travelling 8-10 inches, miss its target by a tenth of a millimeter. :)

    Not so sure about this one. I don't see it as too likely but with tolerances so small inside hard drives maybe. One thing to keep in mind, HDs actually have pretty powerful magnets (they're small but neodymium) inside of them to move the head - the field is well-controlled with mu-metal pole-pieces but there's still a bit of stray.

    How exactly do they do that? It's very hard to shield against magnetic fields. Takes a good deal of highly-permeable metal.

    I'll take back what I said, however - I don't know for sure it won't damage your computer physically.
  17. I was at a camp-ground a couple of months ago, attending a "ham-fest", and there was the usual jam-session in the evening. The bass player didn't have an amp, but had a really huge (loud) stereo system in his car, and so rigged up his bass to play through the car system. It sounded pretty good but after about an hour or so he suddenly lost all power as he'd completely drained the car battery, and so had to get a push-start to get the car running in order to charge the battery. It sounded quite good - as I'm sure all his neighbours will confirm...

    - Wil
  18. jlmorgan


    May 12, 2002
    In my experience with working with computers you have to put a magnet really close to a component such as a hard drive for it to actualy damage it. Also in most cases the damage is mostly to data and there are no permanent effects. Once while putting together a system for a friend I didn't notice I was using a magnetic screw driver until I was connecting cables at the end. It still worked up fine. If a magnetic screw driver in physical contact with the internals will not damage them then setting for instance, a laptop, on a speaker cab should not pose too much of a problem.
  19. pkr2


    Apr 28, 2000
    coastal N.C.
    An anti-static bag has no magnetic shielding properties, for all practical purposes. Magnetic shielding has nothing to do with its purpose.

    Magnetic shielding is accomplished through the use of mu metal.

    As weak as the magnetic field from a speaker cab is, it couldn't possibly affect a computer. The magnetic field from the power supply transformers is much higher than anything that a speaker cab could possibly produce.

    The monitor of your computer or tv set has a pretty strong magnet (degausing coil) built into it. The yoke on the CRT has an unshielded magnetic field.

    Most electronic devices are loaded with magnets. Every AC conducting wire has a magnetic field.

    I seriously doubt that a transistor switch can be turned on or off with a magnet at all. Unless of course it was a hall effect device.

    A floppy disk definitely can be erased with a magnetic field but it has to be an alternating field or have relative movement between the disk and the magnet.

  20. okay.

    for a bass speaker to work it has to have a negative and positive current korrekt?
    so isnt it natural to assume that the polarities of the speaker would reverse along with the currents?

    hence the afformentioned "hall circuits or something" which could verywell change the direction of a current i believe.

    ALL electronic devices are suceptible to any kind of magenetic interference. magnetic drives more so. CPU's probably. RAM most definately.

    so who ever wants to preform this experiment. why dont you jsut send me the money your going to be wasting on a lap top so i can buy me self a good bass rig.