Subwoofer cross-over frequency with small satellites

[Unregistered]

I've read alot about setting the cross-over frequency for your receiver's sub out, but advice can be conflicting. Obviously, one can experiment and see what they feel sounds best, but I was hoping to get some opinions for this modest setup:

Onkyo TX-SR501
4 JBL N24 - 4" woofer, 1" tweeters, 75Hz - 20kHz (-3db)
1 JBL NCenter - similar to sats, but I think 60Hz - 20Khz
1 JBL Sub - 27Hz - crossover
Connected in the usual way, from receiver sub-out to lfe in.
[LFE in bypasses subs internal crossover]
Small room - ~ 15X10

Rule of thumb I've always seen is xover should be at least one octave above f3 point of speakers, which would make it 150Hz. Onkyo manual suggests 120Hz (based on 4" woofer - just a general guideline). 120-150Hz seems to be reasonable, but may be too high as it may allow the bass to become localizable. 80Hz might match, if the sats really do have usable output at 75Hz.

If YOU had this setup, what would you think is a good xover frequency to use?

 

[annunaki]

I would try multiple x-over frequencies and placement in my room until I found the best overall response to suit my liking. This is typically why I recommend people to stay away from sub sat systems if they can at all afford it. Especially if they will double as a music system. You may be able to find a good balance for the x-over with the sub for movies, but if you are going to use the system for music as well everything will change. For music, in most cases, sub x-overs sound best below 60hz as they become much more detetctable above that. In your case try it around 70hz -75hz as a starting point. Experiment from there.

 

[av_phile]

If your satellite speakesr indicate the -3db roll off point, that would be a good place to start for the sub-crossover frequency.

It would be a good idea to get a test CD like Sheffield's My Disc which has a sweep of LF to check the transition between your satellites or main speakers with the sub. An SPL metere would come in handy at your listening position. Otheriwse, I'd just use my ears.

A crossover of 80hz would be just in the boundary for directional low frequencies. Anything higher and you would need two subs for L and R placement. To determine directionality, use a headphone and you could clearly distinguish between a mixed down mono bass and a stereo bass.