How to determine suitable crossovers for all speakers in a surround system the right way?

[Isak Öhrlund]

Hi,

How can I determine suitable crossovers for all speakers in a surround system? I can use REW to measure and determine the right crossover for the main speakers (Front L and R), i.e. which crossover that gives the best integration with the sub(s), but what about the rest of the speakers?

 

[ryanosaur]

Start off by setting the avr xos at an octave above the lower rated frequency of your speakers. I have a pair rated at 65Hz and have the xo rounded down at 120Hz... Another pair is rated at 48Hz with audible output at 34Hz and I have those set to 90Hz.
At that point, its a process of just listening to them and seeing if there are any signs of distortion with too much LF being fed to them. If you are really concerned, set your XO at 1.5 octaves above and adjust accordingly.

 

[everettT]

What speakers and subs? Ported and sealed speakers vs ported and sealed subs require different settings. You want to match the roll off to one another. Typically I'd like to be an octave above the mains and center, but that's not set in stone. Again depends on your gear

 

[Isak Öhrlund]

ryanosaur, how would you go about doing that listening in a surround setup? Would you just stand next to each speaker, or would you somehow disconnect and listen to each speaker independently?

everettT, I am running the following:
2x Dali Zensor 5 as front L/R, ported, rated 43 - 26 500 Hz
1x Dali Zensor Vokal as center, ported, rated 47 - 26 500 Hz
2x Dali Zensor Pico as surround back, ported, rated 62 - 26 500 Hz
2x Dali Alteco C-1 as Front Dolby Atmos upfiring, sealed, rated 74 - 25000 Hz
2x XTZ 10.17 Edge as subwoofers, ported, rated 20 - 180 Hz

Is there no way of determining the crossover using measurements as with the fronts?

 

[ryanosaur]

I'm not as skilled as everettT yet, in terms of matching roll off. Rather I am simply operating on how I hear what's going on using the octave above technique. Where I've questioned how I should set, I've used test tones I found on Apple Music: Power Tools by Bass Mekanik. And yes, I would isolate that pair and play the tones... to hear how the speaker is handling the frequencies.

 

[everettT]

Most AVRs set the crossover slope at 24dbs , if you have sub that's sealed that is the first issue . Most avrs assume you have sealed mains so the slope is short. If you don't have a sealed sub and ported it get complicated. Integration isnt cut and dry. Bass management is a lot of math.

Since your mains and sub follow the same slope, I'd move the crossover 1/2 an octave above. IIRC the lpf would be a bigger issue. Again @TLS Guy explain it better

 

[Isak Öhrlund]

Thank you both. I'll give your recommendations a try!

 

[KEW]

Most AVRs set the crossover slope at 24dbs , if you have sub that's sealed that is the first issue . Most avrs assume you have sealed mains so the slope is short. If you don't have a sealed sub and ported it get complicated. Integration isnt cut and dry. Bass management is a lot of math.

Since your mains and sub follow the same slope, I'd move the crossover 1/2 an octave above. IIRC the lpf would be a bigger issue. Again @TLS Guy explain it better

I'm confused!
If you have an AVR with bass management, don't you choose a XO frequency that avoids the natural roll off of the speaker such that there is no interference with the XO? It is not like the AVR is trying to match the sub to the speaker's natural roll-off!
What am i missing?

 

[everettT]

I'm confused!
If you have an AVR with bass management, don't you choose a XO frequency that avoids the natural roll off of the speaker such that there is no interference with the XO?
What am i missing?

Yes your correct. That's what I was sayin in a nutshell. Some gear allows for adjustable slopes not fixed which makes integration easier. Fixed 24db per octave from the avr with a sealed sub at 12db per and 1st order mains takes some time to get right (just an example) TLS has explained in detail these issues with a fixed slope from the avr and is way more technical them I am so his explanations maybe easier to follow. Hopefully he will chime in.

Most often we hear start with 80hz and go from there, so I was pointing out that sometimes you can achieve a better result working out the math.