Subwoofer crossover, receiver crossover, or both?

Tyro · February 2010

I just read the link that Pearsall001 provided.

http://forum.ecoustics.com/bbs/messages/34579/128214.html

That answered some questions I had. Also reading through this whole thread answered almost all of the rest. There is a tremendous amount of collective wisdom in this group.

As a beginner in this field of home theater, I'm sure I will be lurking around quite a bit.

I do have one question tho...I purchased the 95 pack (5 rm8's) and a PWS505 sub. If the rm8's are:
Overall Frequency Response 95Hz-24kHz
Lower -3dB Limit is 130Hz, does that mean the speaker only works well down to 130Hz?

So if my sub is:
Overall Frequency Response 23Hz - 160Hz
Upper -3dB Limit 125Hz
Crossover Variable low pass 60 - 125Hz, 4th order(whatever that means)

Will I still set the crossover to 120? The link provided seems to point to 80 being the magic number, but if I'm interpreting the info correctly my speakers don't even respond to a signal that low.

The question sounds lame as I write it, but I am truly a novice. Never used a sub woofer before.

Thanks for any replies

McLoki · February 2010

Yes you are correct. Provided your main speakers have a -3db point of 80hz or lower, you should set your speakers crossover at 80hz. (you would set the subwoofer LFE crossover (if your AVR has that setting for the subwoofer) to 120hz.

In your case, with your speakers, I would try 120 and 150hz and see what sounds better to you. I would guess that 150hz may be a little to easy to localise the subwoofer and if that is the case, you may want to try at 120hz.

Anyway - give it a shot, try some different settings, and let us know what you think.

Michael

niles300z · September 2010

I am always replying to things years after the fact, but here goes.
I have heard that a powered sub with a built in variable crossover like my Velodyne X-10 , and a receiver with a crossover built in as well, will be a problem of having two crossovers, if not wired through the "Polk Method"
Please advise.

kuntasensei · September 2010

niles300z wrote: »

I am always replying to things years after the fact, but here goes.
I have heard that a powered sub with a built in variable crossover like my Velodyne X-10 , and a receiver with a crossover built in as well, will be a problem of having two crossovers, if not wired through the "Polk Method"
Please advise.

The key is not to have the two crossovers overlap and cause a gap in response. Typically, you can just dial the variable crossover up to its maximum, then let the AVR handle all the bass management on a digital level.

The so-called "Polk method" of setting your mains to large, then wiring them through the subwoofer so that the sub controls the transition has several issues, primarily phase and time alignment. It's better to let the AVR handle all the bass management so that your channel delays can line things up without any analog crossover in place to alter delay.

coldmark · September 2010

kuntasensei wrote: »

The so-called "Polk method" of setting your mains to large, then wiring them through the subwoofer so that the sub controls the transition has several issues, primarily phase and time alignment.

Another fact that people like me don't always understand is that when using the "Polk method", everything is passed through the sub to your mains. It's just as if they were hooked up directly to your receiver, no bass is filtered at all. So if you have satellites or smallish bookshelves, you're sending them the low frequencies whether you like it or not.

coldmark · September 2010

In my post above, I'm referring to most subs. Obviously there are a few subs out there that have a high pass filter. I was thinking about some of Polk's base models and some of their competitors when I made my statement.

Subwoofer crossover, receiver crossover, or both?

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