Subwoofer Crossvovers

[landoco]

What is the determining factor to selecting the crossover point? Currently I have e speakers with built in subwoofer amp with the crossover set at 40. The woofers are 12” and the mids are 5.25”. Does one really want everything below 40 going to the sub or is a better crossover point 100? Or is the setting more a personal thing to compensate for all other listening variables?

Also, when is it best to set your speakers to large or small, given a sub is in your overall setup?

I am just trying to understand some of the intricacies/subtleties of speaker and amp set up.

[F1]

I don't think there's any fixed rules on how to set up subwoofer. It's more personal thing like you said given particular system and room. However, it is not adviseable to set the subwoofer crossover too high (like 100Hz) as the subwoofer will reveal its location and damage 'imaging'. If your main speaker can handle low freq better than the sub you may set the crossover freq lower, but if you feel the sub can handle low freq better that the mains you may set higher crossove freq. You may need to try diferent receiver setting like small or large and also receiver LFE crossover freq. Generally large setting gives minimum/no output to LFE channel while small setting sends all low freq (below the receiver crossover freq) to LFE channel. Oh wait a minute, this may not applicable depending on your connection setup as you have subwoofer built in the speaker. Anyway, experiment is the keyword. Good luck.

[kexodusc]

I believe 80Hz and below is where low frequencies become "non-directional". What I mean by that, is you can't tell that the sound is coming out of your sub-woofer, instead it feels like it's all around you. It might be closer to 70Hz, but I seem to have 80Hz in my memory for some reason...anyway.
The following seems to be the most frequently suggested method on these forums:
Assuming you have full range speakes, try setting them all to "small" while setting your receiver's LFE cutoff at 80 Hz or lower (if you can). Some older Yamaha's have it fixed at 90 Hz, that's okay too. Disable the LFE cutoff on your sub, or turn it all the way up if you don't have that option, so your receiver alone handles the LFE cutoff at 80Hz.
This I find to be a good starting point for most systems, you can easily adjust the subs level to blend in with the speakers now. I find this method very quickly eliminates the speakers and subwoofer from overlapping their bass outputs, so 80Hz isn't louder than the lower or higher bass signals.
If it's a bit too bloated or boomy for you, try cutoffs at 60Hz and lower until you're happy.
Of course, depending on your system and preferences, you make like bass exaggerated for movies, in which case you can go back to "large" setting, or raise the cut-off frequency to your liking.
Good luck.

[piece-it pete]

Landoco,

As usual you have gotten good advice, you have to experiment. It may take listening for a couple days at one setting, the the next for another couple of days, etc. It took me quite some time to get mine where I thought it was best.

You might try running the speakers full range, without being crossed over, as well, sometimes this works.

Have fun!

Pete