Connecting the subwoofer:
The Micro Subwoofer is equipped with both High-level (speaker level) and Line-level (RCA/pre-amp level) inputs. If your
amplifier/home theater receiver has line-level subwoofer output(s), this hook-up method is greatly preferred, since it has the distinct
advantage that you can use the set-up on your receiver For this hook-up method we strongly recommend using RCA cables with gold
plated terminals, since these will never oxidize and introduce noise into your signal path.
If your amplifier/home theater receiver does not have any line-level subwoofer out, you will have to use the same high-level (speaker
level) output that goes to your mains. The subwoofer has a passthrough (“high level out”) to feed the same signal to your mains.
Connecting your subwoofer using Line-Level Input
If you are using one subwoofer and your amplifier/home theater receiver has one subwoofer output, simply connect the output on your
receiver to the input on the subwoofer marked “mono” and proceed to the section on setting the controls on the back. If your
amplifier/home theater receiver has stereo line-level subwoofer outputs, be sure to connect both of them to your subwoofer so that you
don’t lose any information.
If you are using two subwoofers and your amplifier/home theater receiver has two subwoofer outputs, connect the output of each of
these channels to the “mono” input on the corresponding (left or right) subwoofer. Proceed to the section on setting the controls on the
back of your subwoofer. If your amplifier/home theater receiver has only one subwoofer output, you will need to split the signal by
means of a Y-shaped RCA cable. Feed this mono output to the “mono” input on each of your subwoofers.
Connecting your subwoofer using the High-Level Input
If you are using one subwoofer and your amplifier/receiver does NOT have line-level subwoofer outputs, using speaker wire, connect
the left and right speaker outputs on your amplifier/receiver to the corresponding inputs (marked “high level input”) on your subwoofer.
Then, also using speaker wire, connect your main speakers to the “speaker level output” on the back of your subwoofer that corresponds
to that channel. Be sure to connect the colored or striped wire (positive) to the red/positive terminals on your amplifier/receiver, AND
your subwoofer, AND both of your main speakers. Otherwise, the system will play out of phase.
If you are using two subwoofers and your amplifier/receiver does NOT have line-level speaker outputs, using speaker wire, connect
the left and right speaker outputs on your amplifier/receiver to the corresponding subwoofers. Then, also using speaker wire, connect
the SAME channel “high level output” as the “high level input” that you have running to each subwoofer to the corresponding main (left
and right) speaker. Be sure to connect the colored or striped wire (positive) to the red/positive terminals on your amplifier/receiver, AND
both subwoofers, AND both of your main speakers. Otherwise, the system will play out of phase.
Setting the Controls:
At this time, double check to make sure that your amplifier/receiver is powered down and has the volume turned all the way down, and
that your subwoofer is switched off and has both knobs turned all the way to the left. Plug in your subwoofer. Turn on your
amplifier/receiver, switch on your subwoofer(s), turn on some music with some bass and slowly turn up the volume until you have some
signal going through your main speakers.
Leaving the “crossover” dial turned all the way down, slowly roll up the volume on your subwoofer(s) until you can hear it playing.
Phase control:
Listening from your normal position, turn on some music with punchy bass transients. Tom toms, timpani, and other deep, resonant
drums are especially good for this. If you are using two subwoofers, they should both have the phase set to the same position at the
beginning of this test. Listen to one cut long enough to get a feel for how the bass sounds, then get up and reverse the phase switch on the
back of your subwoofer(s). Go back to the beginning of the same cut you just listened to. In one of the two positions, a phase cancellation
will be occurring between your subwoofer(s) and your main speakers, resulting in a perceived lack of power in the bass. The setting
where the bass feels stronger is the correct position. If you are not sure, go back and try the test again with some different material.
From this point, you will probably not have to make any further adjustments to the settings on the back of your amplifier, but you can
always adjust for taste. If your home theater receiver has a smart setup feature, try listening to your subwoofer without it for a while
before you use it. You may prefer the way it sounds without the extra processing. Remember to experiment!
If you have any questions, give us a call!
Toll free: 800-783-1553
Outside the US call: 718-422-1111
Good Listening!
John Strohbeen
President, Ohm Acoustics Corp.
