theta crossover question

i posted this in the speaker forum last week but i think it is better discussed in ht as this relates to dts/dd settings...

looking for some direction/input on crossover settings in my theta casanova. i typically use the phase perfect crossover and my speakers are wilson wp7's which play down to 21hz, watch center 55hz to 22khz and surrounds 45hz to 22khz. i use 1 thiel sw1 sub.

i realize some is dependant on room and preference but where would you start with crossover freq/slope settings and why?
Can you cross the center over independantly from the L R and rear?

If so I would set the L R crossover to about 30hz 12db/octave

set the rear 50 hz 12db or 24 db

set the center @ 50 12db or so

set the sub to play 50hz down about 24 db

I personally like the L R to be as full range as possible.

Having a little overlap from sub to L R will help with integration of the sub, although the Thiel sub likely integrates very well anyway.

Hope that helps.
thanks for the response buff. they can all be set independently but only down to 40hz. why set the center at 50 if it only plays to 55?
Hi Richard,

55hz is likely the 3db down point of the speaker, but it will produce sound beneath 55hz, the speaker just naturally rolls off at that point.

The main purpose of any crossover - active or passive is to take out the frequencies that could damage a speaker, or to basically optimize the frequencies which a transducer is allowed to produce.

I will assume that you can turn off the crossover for the main L R?

So I would set it to OFF for L and R

and use the other settings recommended above.

The reason I say 50 for the center is that you want the center to be as full range as possible. If the speaker naturally has a 55hz 3db down point, a 50hz crossover at 12db/octave will be enough protection and allow you to get as much full range sound from the driver as possible.

Use the points I laid out as a guide. Play with them one at a time and take detailed notes to determine what is best for your system and your room.
Find a piece of music, or a movie which is a good reference and listen to it/play it over and over with the different settings and listen to how each change affects the sound.

you may want to run the sub up to 80hz depending on position and how it integrates with the L R speakers.

Feel free to contact me for more help if you like.

happy listening!
Get threat I've been wonder the same question. I've got B&W 802d's. Range goes down to 34hz I was thing of setting to butterworth 63/18 and center HTM2D 41HZ same 63/18. My sub is a paradigm servo 15. Specs say it'll go down to 17hz. I've always set the crossover to 80/24 accross the board. I just want to try something new. Any additional thoughts?
stick70--- i use the phase perfect crossover. theta says it should sound most accurate and it does to me although some may be just because i think it should. i have set the frequency to the lowest point closest to the speakers spec frequency. this allows the speakers ot carry most of the sound and the sub to pick up what is left. i did not turn off the crossover on the l/r as recommended above as i did not want to put that much strain on my wp's, let the sub do some work.

by the way, love allot of your set up. i lust after the gen vii series ii and the sixshooter/cb combo.
Hey Richard,
Thanks for the response. So you’re using different crossover points based on the spec frequency of each speaker? ie L/R 40hz Center 50hz and so one. Do you use some type of EQ? I'm using the SMS for my subs. The frequency response on those subs are 17hz to 80hz with a slope of 18. Should I match the slope of my sub to the speakers and what should I set that cross point to? What's an acceptable over lap?

My next question on the Theta gear is when you turn off the crossover (set to full) does setting the crossover in the Casablanca or Casanova make any difference? I've read posts of people setting their L/R to full yet they are still setting the crossover to 40/6 or whatever. I'm a bit confused on that.

I've actually changed some of my equipment since last updating my system here on agon. What I've done is installed the digi out card into the Casablanca so I can use the Gen 8 V.2 as an external Dac/analog preamp. It works seamlessly and a nice upgrade even over the extreme dacs in the Casablanca. I have a Analog rig and did not want two systems so the digi card made it possible to separate the two plus the added quality of the dacs was a nice upgrade for HT.

Thanks for your help!
i do not use an eq other than what exists in my sub (thiel sw1) and the casanova. your questions are close to why i started this thread a while ago! i do not know! i think that the slope should be 12 for most of my settings and that tends to be where it sounds best.

off the top of my head, i do not think the crossover settings do anything if the setting is on full so i share your confusion regarding those posts.

that sounds stellar i am sure. i have been using the dac in my casanova as my digital source with a squeezebox duet and really want to upgrade that piece. i also need to add a preamp as the casanova is not up to the level of most of what i have. even moving up to the cb3 would probably not be that much of a change (i think). make sense?? basically, i need a preamp and a dac upgrade. maybe add a transporter too to replace the sb. butlike you, i have combined ht and 2 chan. makes it tricky.
Ok well thanks a bunch for your responses. At least you know what I'm trying to find out. If I hear anything that answers these questions I'll post back.

I think if you bump up to a CB3 w/extremes you'll hear a major difference IMHO. Hopefully Theta will complete their HDMI upgrade but it might take some time. Theta's new website looks very sharp hopefully this is a good sign. At one time Theta was allowing 1st owners of the casanova to upgrade to the Casablanca seeing that they ended the life of that unit. Now that ATI owns them I don;t know if that's still available.