active subwoofer and 2channel amp.

[calvin14]

hi,

I would like to ask for guidance here as to what is the best way to set up the following equipment:
1)2 bookshelf loudspeaker
2)1 amplifer with 2 speaker level output.
3) 1 active subwoofer. has line level input and speaker level input. also has speaker lever output.

The source is line level output from a laptop.

So obvious the easiest way to set up is:
laptop --(line out)--> amp --(speaker output)--> Active sub --(speaker output)--> loudspeakers.

howeever, as much as possible i don't want my speakers to run from my subwoofer plate amp as my amp should produce much better sound.

so i was thinking of splitting the output to 2 line outs, one to connect to the amp, the other to the line level input of the amp.

laptop
(y splitter) --------> amp ----> speaker
|
'-----> sub

however i read that you need to consider the input impedance of each input. i don't understand how to.



also another possible method to not use the subwoofer's plate amp altogether is connect an additional amp then connect the speaker outs to the sub.

laptop
(y splitter) --------> amp ----> speaker
|
'-----> amp --(speaker outs)--> sub

this way, because both input impedance of the 2 amps are the same, hence shouldn't have any problem?


please help!! thanks!

[wakibaki]

Originally posted by calvin14
howeever, as much as possible i don't want my speakers to run from my subwoofer plate amp as my amp should produce much better sound.

Connect as per your first idea

laptop --(line out)--> amp --(speaker output)--> Active sub --(speaker output)--> loudspeakers

The speaker output on the subwoofer is a thru connection from the input, the plate amp (mono, driven by a bit of signal sniffed from both speaker channels) will only be driving the subwoofer driver...

w

[calvin14]

so by connecting the speaker outs from the amp to the speaker in to the subwoofer, it will not go through the plate amp?

and hence the signal from the speaker in, goes through a passive crossover in the woofer and comes out as speaker outs?

therefore am i'm right to say the signal will be the cleanest it can be, meaning not going through unnecessary active electronic components?


thank you.

[wakibaki]

Originally posted by calvin14
and hence the signal from the speaker in, goes through a passive crossover in the woofer and comes out as speaker outs?

therefore am i'm right to say the signal will be the cleanest it can be, meaning not going through unnecessary active electronic components?

Yes, depending on the sophistication of the subwoofer the speaker signal will pass through unchanged, or only with bass cut. An op-amp summer and lo-pass filter will extract a signal from the 2 channels to go to the plate amp.

w

[calvin14]

thanks!