SVSound

**bone215** · **09-02-08, 08:16 PM**

Just to play around, I turned on the crossover on the sub and lowered it to around 90 ish to see if any change in sound.
Slight change, seems a little tighter, with more emphasis on the lower stuff.
I will have to listen to a variety of music and movies to see.
Most advice I have read was NOT to do this, use both AVR crossover and sub crossover, but hey, it's time to play.

**E-A-G-L-E-S** · **09-02-08, 08:17 PM**

If I am not mistaken it will only use the lowest x-over, not both.

**bone215** · **09-02-08, 08:28 PM**

Eagles
what do you mean? I thought the AVR's crossover was not a brick wall type of thing. E.G. if I set it to 80 Hz isn't there a slope which determines how much over 80 Hz rides along with it?

**E-A-G-L-E-S** · **09-02-08, 08:50 PM**

You are correct, an 80Hz x-over point in your AVR is a gradual slope below that, not a cut-out filter.
But....say you have your avr @ 90Hz and your subs active x-over at 80Hz.....it will roll off from 80Hz not 90Hz.

I could be wrong, but that is what I think is correct.
Someone with more knowledge than I will come along soon to help, I'm sure.

**salvasol** · **09-02-08, 08:56 PM**

Quote:

E-A-G-L-E-S wrote:

You are correct, an 80Hz x-over point in your AVR is a gradual slope below that, not a cut-out filter.
But....say you have your avr @ 90Hz and your subs active x-over at 80Hz.....it will roll off from 80Hz not 90Hz.

I think EAGLES is correct ... that's why I've seen that is recommended to set the crossover at the AVR @ 80Hz and at the sub higher than 80Hz to avoid that the sub crossover takes over

We'll wait for an answer from the experts

**tonyvdb** · **09-02-08, 09:07 PM**

If you are using the crossover in the receiver then set the crossover switch to off on the PB 13 do not use both.

**bone215** · **09-02-08, 09:09 PM**

Eagles
at Avr set at 80, isn't it a gradual roll off above, not below??, the crossover sends stuff above 80 hz to the sub, but rolled off? So, therefore a 90 hz crossover on the sub cuts those above 80 frequencies even at a more rapid roll off?

**E-A-G-L-E-S** · **09-02-08, 09:19 PM**

You are approaching this from the opposite angle of normal which is confusing.
Just use one(typically avr) and place it wherever you like it best...don't use both.
But yes, it rolls off the frequencies above it's point not below....sorry about that.
But it will still go by the lower one of the two..it can't utilize both at the same time I don't believe.

**Ed Mullen** · **09-03-08, 06:04 AM**

The more accurate description for that control on the subwoofer is a low pass filter. The slope of the filter is 12 dB/octave.

The slope of the digital low pass filter in the AVR crossover network is 24 dB/octave.

When both filters are enabled, they will cascade (combine) above the higher of the two settings. So if the AVR crossover is set to say 80 Hz, and the PB13-Ultra low pass filter is set to 120 Hz, the initial slope of the subwoofer roll-off will be 24 dB/octave above 80 Hz, increasing to 36 dB/octave above 120 Hz.

**bone215** · **09-03-08, 10:05 PM**

Thanks for all who jumped in here with comments, I appreciate it.
Ed, you have a very good knack for writing about this stuff, brief and to the point, you clarified what I was trying to think and express. Theoretically there could be a situation where the both controls could be utilized to create a better listening experience.
I do think in my case, it is all good, I just like to play. I also think the next expenditure will be on bass traps to reduce the room's influence on the sound.
Thanks again all.
SVS did a really good job with this sub, I guess you can't tell us what is next on the sub drawing board?????

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