AMP and SUB WTF

[reverber8]

I know this has nothing to do with music production but -

i would like to hook up a sub and im about to sell my old speakers+amp and was curious as to how i can get this done
shop assistants are dead useless i would appreciate the help

[phunkdust]

well generally subs come in two flavours - powered and unpowered...

the powered kind have their own amp - usually you just add 240v and an RCA lead from the inputs to the sub out/pre out/tape out/aux out/line out of your main amp

unpowered kind - wire up amp to speaker, the amp may or may not have a cutoff filter (ie filters out highs) if the sub amp doesnt have one and your main amp doesnt have one (ie no sub out) then you'll need an external cutoff filter... after that its main amp line outs (as for the above) into the sub amp (thru filter if neccesary)

of course if you're taking the sub sound from a surround sound decoder (low freq effects channel) they usually have filters built in

if you're running a dedicated sub amp they will have filters (usually adjustable)

its sometimes a pain to get the right kind of line outs to run the signal to the sub amp - if you think for a minute, line outs have a constant output level, which means you'd have to adjust main volume as well as sub volume - which can get annoying.

some main amps have preamp outs, which vary output according to the main volume level - all you have to do here is set a volume, and trim the volume of the sub to get a nice balance and then you have one main control for both.

[driload]

can get expensive if you need external crossovers


very expensive (for quality)


your neighbours wont love you much either (bass waves are longer and near impossible to insulate.... believe it or not your neighbours "get" better sub bass then you do!!)

[phunkdust]

dri, I used the parametric sub kit from jaycar - has cutoff, infrasonic cut, boost/cut frequency and boost/cut level.

It's about $40 worth and the quality is fine, it sits in the amp as a pre-stage between the preamp out from my main amp and the subs main amp (300w mosfet stylin)

all the neighbours are noisy at times too so I don't get hassled for my sub, despite it being quite a fierce one. 8-)

[driload]

sounds like you're sorted :P


where would we all be without JAYCAR

they may be as rude as fuck but they arent TOO expensive and have neat things like theremin kits :)

[phunkdust]

i get all my shiznit from jaycar... they rock