How to work out crossover?

andrewtayloruk

Active Member
Hi,

I've got a set of Canton Movie 1 speakers with subwoofer hooked up to a Denon 1906.

The Subwoofer has a dial for crossover frequency, starts at 80 goes all the way around to 140.

The Denon also has an option for crossover frequency.

Can someone give me a guide as to what crossover is, how I should set it up, and, how I can test to make sure it's working OK?

I seem to be getting some noise of the unit but it's not very loud, or doing very much. The THX setup disc from the Incredibles barely raises a whisper from it.

Thanks

Andrew
 

Mr Incredible

Distinguished Member
A crossover is not a cliff or wall beyond which a signal will drop off or go no further. Most crossovers will attenuate the signal at the rate of -24dB per octave above or below the crossover frequency (depends if you are looking at it from a sub or amp perspective). What is clear though is that with bass management on the amplifier the subs crossover should be set to 140 (or off if there is an option). Then, as a rule of thumb, the crossover on the amp should be set to twice the frequency of the rated (lower) frequency response of your speakers.

If you find that the FR of the speakers is quite high and the sub therefore taking on more of the lower frequency duties, then with a higher crossover on the amp, say 100Hz or higher, you may find that you can "locate" the sub as it goes through its paces. Subs should be heard and not "seen".

As far as testing is concerned, your amp can produce test tones to set the level. In auto set up using the mic you should be able to hear the sub with your settings in place as the amp cycles and tests the speakers and sub for levels. Which reminds me, set all your speakers to "small" in the menu options along with the crossover level you think you should have.

HTH
 

andrewtayloruk

Active Member
Thanks - that's helped a lot. If the Amp has the crossover set to 100Hz, then I change it to 120Hz, does that mean the sub does more work or less work? I'm trying to work out the direction.

The tone-test indicates the sub is working, I can hear it rumble, but, during movies etc, I can't really tell if it's doing it's thing. Is this actually the desired setting, ie, you can't work out where the sound is coming from?

Thanks again

Andrew
 

Mr Incredible

Distinguished Member
Changing the amp crossover from 100 to 120 will send more signal to your sub and therefore it should be doing more work.

If you wanted to try another approach you could set your speakers to be LARGE in the amp set up, and then set the amp to send the sub "LFE + Mains" if that is an available option, In this way you will get your speakers AND your sub working at the maximum they can be with the available frequencies. The only potential issue with this is that where the sub and speakers are producing the same frequencies from the same source, then if the phase setting of the sub relative to the speakers and relative to your sitting position is not 100% on, you may get cancellation of certain frequencies and the sound may appear a bit flat.
 

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