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Subwoofer Crossover

Scott Wilkinson  |  Nov 14, 2011

I have a Yamaha RX-V2400 A/V receiver driving a set of Boston Acoustics VR2 towers and a Boston PV1000 subwoofer. My question is what crossover, if any, should I set on the front of the subwoofer? It has three controls—a selector switch with 50, 80, 120, and 150Hz; Crossover Set or None; and Polarity None or 180. I did not get a manual because it was a floor model. My bass sounds odd and it is bothering me.

Greg Peckinpaugh

With a setup like this, you definitely want to disable the crossover in the subwoofer, so set the Crossover switch to None. The RX-V2400 (reviewed here) is performing the crossover duties, which direct the frequencies below the crossover point to the sub. (In the RX-V2400, you can set the crossover to 40, 60, 80, 90, 100, 110, 120, 160, or 200Hz; 80Hz is the default and most common setting.) If the sub's crossover is engaged, the signal it gets passes through two crossover filters—one in the AVR and one in the sub—which can make it sound weird. If you disable the sub's crossover, that should fix the problem.

For those with a subwoofer that has no crossover on/off switch, set the sub's crossover frequency as high as possible and make sure the crossover frequency in the AVR is lower than that. This is not ideal, but it's the best you can do.

The Polarity switch controls the phase of the subwoofer, which can potentially help even out some irregularities in the bass of the system. Try it in both positions and see if there's any difference in the bass performance. If so, use the setting that sounds better.

If you have an A/V question, please send it to askhometheater@gmail.com.

COMMENTS
mailiang's picture
Submitted by mailiang on November 14, 2011 - 12:54pm

Setting up a subwoofer is often not an easy task, but once you get familiar with the proper procedures it will be a breeze. These are the most common.

Subwoofer's crossover set to off or MAX setting.

AVR Settings:

All speakers set to small.
AVR crossover set to 80 Hz. (Unless you are using very small speakers).
Subwoofer set to on/yes.
LFE + Mains set to off/no.
Dolby Dynamic Range Compression (DRC)or Midnight Mode circuit set to off/no.
LFE channel enabled.
LFE channel level, NOT attenuated. Full on.
THX modes (if you have one) off.
Subwoofer pre-out level range set to 0 (flat). (Some audiophiles recommend -5, but you can tweak these levels depending on the source, your room conditions, and your listening tastes).

Subwoofer phase control, set to 0 then 180 using your AVR's test tones. Keep the setting that sounds the loudest.

Scott Wilkinson's picture
Submitted by Scott Wilkinson on November 15, 2011 - 5:05pm
Thanks for posting this!
Mittchell's picture
Submitted by Mittchell on November 15, 2011 - 7:17pm

This all makes sense to me but,the one setting that I don't understand is the " L.F.E. + Mains " setting.

I would appreciate it if someone would further explain this setting. Thanks.

mailiang's picture
Submitted by mailiang on November 15, 2011 - 10:08pm

LFE+Mains refers to sending all the bass below the crossover point both to the main speakers, and your sub. You would choose this setting if you have large full range speakers and want the deeper bass frequencies that would normally come out the front speakers also routed to the subwoofer. On some receivers like my Pioneer they refer to it as the 'plus' mode and it can only be available if the main speakers are set to large. However, in most situations, all speakers should be set to small regardless of their size, since most systems work more efficiently by letting your powered subwoofer handle all the deep bass.

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