Testing theory : cascading crossovers

  • Thread starter Vaughan Odendaa
  • Start date
3db

3db

Audioholic Overlord
Agreed

If it was a brick wall filter. But because it's a slope, the sub will still be getting signal for frequencies above the crossover point (though at progressively lessening amplitude).

The point I'm trying to make is this,, I would think that the filter on the receivers effect the signal first before reaching the filter of the sub itself. So if dialing a cutoff frequency at the receiver say around 80Hz, dialing the sub around 90 Hz will have very little affect as the 90 Hz is already being dealt with by the receiver's low pass stage. Secondly phase becomes an issue because every filter be it low, band, or high pass introduces phase delay (don't want to use the word distortion hear cause I don't know if its technically correct). Unless you have a contioulsy variable phase control on your sub ( which mine does not, just 0 and a 180 degrees) your gonna find it harder to dial the sub in properly.

The kind a fiilter that is being employed as the low pass will also determine how difficult it will be to dial in the sub as well. Some filters have an emphasis on keeping the phase shift to a minimum at the expense of an even amplitude response while others trade off phase for an even amplitude response (Butterworth) .
 
annunaki

annunaki

Moderator
Just to get the thread back on topic, can MDS, WmAx or Gene (or anyone with a techical background) offer their thoughts on the graphs and let me know what they think ?

I'm glad that at the same time this thread will help people configure their systems better, but I don't want this thread to be sidetracked.

Thank you.

--Regards,
I appreciate your comments here. Wmax had asked you for specific readings from your screen shots. If you did not comply correctly with his requests, he will not be able to help. Please reread his requests and take the subsequent measurements and post the screen shots.

To all, please keep the thread on topic as per the OP's request. Start your own thread or PM me and I can create the thread for you from this one by removing your posts.
 
WmAx

WmAx

Audioholic Samurai
Annunaki is correct concerning failure to provide the graphs I specified. I made the specific request in order to get an idea what is going on. BTW, since you would need to make new measurements anyways, I need to add to the fact that you need to only measure the subwoofer. Deactivate or disconnect the wires from other speakers. The issue here is the low pass crossover behaviour of your system. If you want to analyze the high pass as well, this will require additional measurements.

-Chris
 
V

Vaughan Odendaa

Senior Audioholic
Unfortunately I don't have a subwoofer with a variable low pass filter (I currently own the SVS PB10 ISD). My subwoofer from work went back. Although I guess I could use the SMS-1 because it too has a built-in low pass filter (it's currently bypassed in the SMS-1).

Would that be alright ? I'll do my best to comply with your requirements. As I said before, I was really in a hurry but tommorrow I'll be off work so I'll have more time to experiment.

Thanks.

At least with the graphs I posted, one can see a reduction in output around the crossover point which is to be expected. I must have been really naive to expect complete or close to complete cancellation at the crossover frequency for various reasons I now understand (or think I now understand).

--Regards,
 

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