Proper crossovers for my home theater?

[Dmantis10]

I have an issue with crossing over any speaker in a theater room below or above 80hz.
Most speakers can not reproduce well signals under 80hz as a good quality subwoofer can. Also this takes load off your AVR or amp that drives given speakers.
Now in your case Def Tech is suggesting 120hz on the hone and 100hz in the manual but the speaker is rated to 50hz. Interesting suggestions but I have a problem with all of them.
80hz is a magical place when local and non local tones start to change. You don't really call attention to a sub at 80hz and lower. If your going to redirect signals above 80hz to a subwoofer , those signals now become local and the sub can all attention to itself.
YES I know LFE is a channel and has frequencies above 80hz up to 120hz on that channel. BUT I in my 20+ years ever sent and left it sent signals to a subwoofer above 80hz with great success and integration with the rest of the system.
All my theater I setup and surround systems get a Small setting on all channels at 80hz and I also cross over the sub LFE to 80hz as well. This is the very best option for just about everything made. Super small output speakers that can not reproduce signals down to 80hz I feel personally have no business being apart of a surround system. I'm a huge Definitive Technology speaker fan and Owner of a full Mythos system.
I think IF you test those speakers and they can't reproduce 80hz and up faithfully they need to go. You can get in walls from Def Tech that will perform extremely well, you won't have to use a Bi Polar design unless you enjoy it as Def Tech loves to use that technology then you can get the Bi Polar in walls and perform much better then the 9040's do.
I'd like to call them myself and argue your case here. The way bass is handled in the room is important to the overall experience of the entire system. When you get that wrong, the system doesn't sound enjoyable.

 

[snakeeyes]

Pro sub 1000

This sub probably needs to be upgraded. I would recommend looking at HSU Research. The HSU VTF2 MK5 would be a huge upgrade over your current sub, assuming you don’t live in an apartment or condo where it would be too loud.

 

[everettT]

I cross my subs @110hz and I have no issues. There is no magic number as it can be speaker, sub, and avr/prepro dependent.

@TLS Guy can explain slopes better, hopefully he can chime in

Looking at the FR I'd be above 80 for sure.

 

[snakeeyes]

I agree with Everett.

 

[Swerd]

There are no definitive () answers to this question. Bass responses vary widely among rooms with different dimensions, as well as different speaker and listener locations within the same room. In rooms most of us have in our homes, bass below roughly 250-300 Hz depends more on room dimensions and locations than the performance of the speakers themselves.

Search Google on "Schroeder frequency" and take your pick on what to read. If you want a full explanation, see Room Acoustics by Linkwitz Lab. Read as far as you can before he looses you in the math. Another simpler explanation is on Wikipedia, Room Acoustics.

So, I think the best answer to the OP's question is to try a number of different crossover frequencies, by trial & error, until he finds something that works, or until he gets tired of fussing over it.

 

[lovinthehd]

I have an issue with crossing over any speaker in a theater room below or above 80hz.
Most speakers can not reproduce well signals under 80hz as a good quality subwoofer can. Also this takes load off your AVR or amp that drives given speakers.
Now in your case Def Tech is suggesting 120hz on the hone and 100hz in the manual but the speaker is rated to 50hz. Interesting suggestions but I have a problem with all of them.
80hz is a magical place when local and non local tones start to change. You don't really call attention to a sub at 80hz and lower. If your going to redirect signals above 80hz to a subwoofer , those signals now become local and the sub can all attention to itself.
YES I know LFE is a channel and has frequencies above 80hz up to 120hz on that channel. BUT I in my 20+ years ever sent and left it sent signals to a subwoofer above 80hz with great success and integration with the rest of the system.
All my theater I setup and surround systems get a Small setting on all channels at 80hz and I also cross over the sub LFE to 80hz as well. This is the very best option for just about everything made. Super small output speakers that can not reproduce signals down to 80hz I feel personally have no business being apart of a surround system. I'm a huge Definitive Technology speaker fan and Owner of a full Mythos system.
I think IF you test those speakers and they can't reproduce 80hz and up faithfully they need to go. You can get in walls from Def Tech that will perform extremely well, you won't have to use a Bi Polar design unless you enjoy it as Def Tech loves to use that technology then you can get the Bi Polar in walls and perform much better then the 9040's do.
I'd like to call them myself and argue your case here. The way bass is handled in the room is important to the overall experience of the entire system. When you get that wrong, the system doesn't sound enjoyable.

Re the LPF of LFE, has nothing to do with your crossovers....

 

[lovinthehd]

Pro sub 1000

DT lists an upper response of 150, so might be fine, might want to drop the surround xover to 100.

 

[Kyle Braunlich]

Thank you all very much for the advice!