Need help with my crossover settings

D

Darthwarren

Enthusiast
Hi i just bought a used center speaker the polk cs10 and what should the crossover be? I have a t30 in my home theater in the basement and thats set to 100. The cs10 is in a livingroom with in wall speakers and in ceiling speakers for rears. What is a good crossover for my in wall and in ceiling. Front in wall are set to 100 and the ceiling are at 120. Dont know the model they where installed like 7 years ago and hardly used.
 
ryanosaur

ryanosaur

Audioholic Ninja
I always say start 1 octave above the bottom rated frequency of the speaker. Experiment up and down from there.

Example: a speaker rated 34Hz - 20kHz.
34Hz... double it to find the octave: 68Hz. Your AVR may not support 70 Hz, so I would start at the nearest point above: 80Hz. (I would not recommend an XO setting anywhere less that 1/2 an octave above that bottom (halfway between the two, so 51Hz in this example.)
Ideally, you won't need to cross any higher than 120.
What you should listen for is CLARITY. Can you hear and understand the Dialog in a movie well?
 
ryanosaur

ryanosaur

Audioholic Ninja
80 is a fine starting point, though I would start those at 100, not 80.
Mind, you also won't necessarily have all speakers set to the same XO.
;)
 
A

AVUser001

Audioholic
I always say start 1 octave above the bottom rated frequency of the speaker. Experiment up and down from there.

Example: a speaker rated 34Hz - 20kHz.
34Hz... double it to find the octave: 68Hz. Your AVR may not support 70 Hz, so I would start at the nearest point above: 80Hz. (I would not recommend an XO setting anywhere less that 1/2 an octave above that bottom (halfway between the two, so 51Hz in this example.)
Ideally, you won't need to cross any higher than 120.
What you should listen for is CLARITY. Can you hear and understand the Dialog in a movie well?
80 is a fine starting point, though I would start those at 100, not 80.
Mind, you also won't necessarily have all speakers set to the same XO.
;)
@ryanosaur
Is this recommendation of "always start 1 octave above bottom frequency" independent of the roll-off rate of slope ? Or is this based on a 12db/octave slope ?

So in this example, his speaker's frequency response is 53Hz - 25Khz

If this is sloping at 12db/octave, then yes a crossover frequency of 1 Octave from bottom(ie 106Hz ), rounded to 100hz will ensure , the bass o/p is atleast 4 times lower (ie -12db) at 53Hz , than what it is at the XO(100hz). So XO of 100hz is fine here.

But if the roll-of slope is 24db/octave, wouldnt half an octave(ie 79.5 rounded to 80hz) for XO be sufficient, to get the same effect (ie -12db at 53Hz) ? . ie Cross-over frequency of 80z will still reduce o/p by the same factor of 4 at 53Hz and get away with a lower XO?

Reason am bringing this up..is my ML 35XTi has a similar frequency range(50hz- 25Khz) and exhibit a 24db/octave slope (and not 12db/octave) from Audioholics measurement. Yes, I'd have usually set it up with a 100hz XO , but looking at the steeper slope I reached out to MartinLogan on the crossover..,and they recommended only half-an-octave above the bottom most frequency (ie 80hz) and not a full Octave(100hz). This was also the recommendation from SVS(ie 80hz) for my speaker with their Sub ..and infact recommending going down to 60hz for subwoofer's LPF in a 2 channel pre-amp setup for my ML bookshelves, given their Sub's amp fixed at 24 db/Octave.

The other potential concern I have with 100+ hz for XO is higher localization than a lower one(like 80hz). In reality localization may not occur until we reach higher frequencies(120+)..,but thats the other thing I had in mind when debating between half-an-octave vs full octave.

Also, the lower end of male voice starts at about 80-100hz. So isnt there a risk of redirecting lower end of male voice to sub-woofer, with a XO of 100+ Hz with possible localization or lack of clarity?

I'm really good with starting at 80hz for XO.., but not too sure starting at a full octave(ie double the bottom frequency) for all cases independent of the roll-off rate and speaker.

Your thoughts ?
 
everettT

everettT

Audioholic Ninja
@ryanosaur
Is this recommendation of "always start 1 octave above bottom frequency" independent of the roll-off rate of slope ? Or is this based on a 12db/octave slope ?

So in this example, his speaker's frequency response is 53Hz - 25Khz

If this is sloping at 12db/octave, then yes a crossover frequency of 1 Octave from bottom(ie 106Hz ), rounded to 100hz will ensure , the bass o/p is atleast 4 times lower (ie -12db) at 53Hz , than what it is at the XO(100hz). So XO of 100hz is fine here.

But if the roll-of slope is 24db/octave, wouldnt half an octave(ie 79.5 rounded to 80hz) for XO be sufficient, to get the same effect (ie -12db at 53Hz) ? . ie Cross-over frequency of 80z will still reduce o/p by the same factor of 4 at 53Hz and get away with a lower XO?

Reason am bringing this up..is my ML 35XTi has a similar frequency range(50hz- 25Khz) and exhibit a 24db/octave slope (and not 12db/octave) from Audioholics measurement. Yes, I'd have usually set it up with a 100hz XO , but looking at the steeper slope I reached out to MartinLogan on the crossover..,and they recommended only half-an-octave above the bottom most frequency (ie 80hz) and not a full Octave(100hz). This was also the recommendation from SVS(ie 80hz) for my speaker with their Sub ..and infact recommending going down to 60hz for subwoofer's LPF in a 2 channel pre-amp setup for my ML bookshelves, given their Sub's amp fixed at 24 db/Octave.

The other potential concern I have with 100+ hz for XO is higher localization than a lower one(like 80hz). In reality localization may not occur until we reach higher frequencies(120+)..,but thats the other thing I had in mind when debating between half-an-octave vs full octave.

Also, the lower end of male voice starts at about 80-100hz. So isnt there a risk of redirecting lower end of male voice to sub-woofer, with a XO of 100+ Hz with possible localization or lack of clarity?

I'm really good with starting at 80hz for XO.., but not too sure starting at a full octave(ie double the bottom frequency) for all cases independent of the roll-off rate and speaker.

Your thoughts ?
Not answering for him, but ported I definitely would an octave (or 1/2 depending)for mains and center. Sealed a half based on their roll off. I cross my theater subs high, above 100hz, and don't have issues with localization (they reach down to the low 30s).

Of course this is all dependent on the gear.
 
ryanosaur

ryanosaur

Audioholic Ninja
@ryanosaur
Is this recommendation of "always start 1 octave above bottom frequency" independent of the roll-off rate of slope ? Or is this based on a 12db/octave slope ?

So in this example, his speaker's frequency response is 53Hz - 25Khz

If this is sloping at 12db/octave, then yes a crossover frequency of 1 Octave from bottom(ie 106Hz ), rounded to 100hz will ensure , the bass o/p is atleast 4 times lower (ie -12db) at 53Hz , than what it is at the XO(100hz). So XO of 100hz is fine here.

But if the roll-of slope is 24db/octave, wouldnt half an octave(ie 79.5 rounded to 80hz) for XO be sufficient, to get the same effect (ie -12db at 53Hz) ? . ie Cross-over frequency of 80z will still reduce o/p by the same factor of 4 at 53Hz and get away with a lower XO?

Reason am bringing this up..is my ML 35XTi has a similar frequency range(50hz- 25Khz) and exhibit a 24db/octave slope (and not 12db/octave) from Audioholics measurement. Yes, I'd have usually set it up with a 100hz XO , but looking at the steeper slope I reached out to MartinLogan on the crossover..,and they recommended only half-an-octave above the bottom most frequency (ie 80hz) and not a full Octave(100hz). This was also the recommendation from SVS(ie 80hz) for my speaker with their Sub ..and infact recommending going down to 60hz for subwoofer's LPF in a 2 channel pre-amp setup for my ML bookshelves, given their Sub's amp fixed at 24 db/Octave.

The other potential concern I have with 100+ hz for XO is higher localization than a lower one(like 80hz). In reality localization may not occur until we reach higher frequencies(120+)..,but thats the other thing I had in mind when debating between half-an-octave vs full octave.

Also, the lower end of male voice starts at about 80-100hz. So isnt there a risk of redirecting lower end of male voice to sub-woofer, with a XO of 100+ Hz with possible localization or lack of clarity?

I'm really good with starting at 80hz for XO.., but not too sure starting at a full octave(ie double the bottom frequency) for all cases independent of the roll-off rate and speaker.

Your thoughts ?
:)
I don't disagree. Mostly... But even there... it is more a function of YMMV.

Most AVRs are generally rolling off the XO at 12dB. Even Ed from SVS has said this. That 12dB slope is likely enough to protect the woofer even if you cross at 1/2 Octave above the F3 of a speakers FR.
Now, forgive the nitpick, but that Polk's 3dB is actually 63Hz... with "Total FR" down to 53... which is either the -6 or -10dB point.
My point being that it is not a great example for trying to utilize as full range as possible. Since most Centers have some issues with clarity, freeing the speaker from being burdened by the lower frequencies often helps it in reproducing the higher frequencies.
I can hear it in my speakers with a F3 at ~34Hz, and I chose 80dB... not because of dogma, but because I can actually hear the difference. I would prefer to cross them lower, but the proof is in the pudding. That clarity and more precise sound was subtle but unmistakable.

If you have the gear to set your slopes and roll off 4th order, then half an octave is absolutely not a concern. But what should be a concern is how the system actually sounds. And many here have said that they actually prefer what they hear with higher XOs: including big towers crossing at 110 or 120. (I'm not that extreme! :p ...but that should just further illustrate the Mileage Factor!)

:)

I liked the Martin Logan Motion series when I auditioned the 60XT... I didn't have them in my own room though, so we were listening at a dealer room, probably full range. Good speakers, but overpriced, imo. The new XTIs looked pretty cool, as I recall. Would be fun to hear them! :D

Cheers!
 
A

AVUser001

Audioholic
Not answering for him, but ported I definitely would an octave (or 1/2 depending)for mains and center. Sealed a half based on their roll off. I cross my theater subs high, above 100hz, and don't have issues with localization (they reach down to the low 30s).

Of course this is all dependent on the gear.
Cool ..,yes "depending" is the key, I think. I just was making a point about "always starting with 1 full octave".
 
A

AVUser001

Audioholic
:)
I don't disagree. Mostly... But even there... it is more a function of YMMV.

Most AVRs are generally rolling off the XO at 12dB. Even Ed from SVS has said this. That 12dB slope is likely enough to protect the woofer even if you cross at 1/2 Octave above the F3 of a speakers FR.
Now, forgive the nitpick, but that Polk's 3dB is actually 63Hz... with "Total FR" down to 53... which is either the -6 or -10dB point.
My point being that it is not a great example for trying to utilize as full range as possible. Since most Centers have some issues with clarity, freeing the speaker from being burdened by the lower frequencies often helps it in reproducing the higher frequencies.
I can hear it in my speakers with a F3 at ~34Hz, and I chose 80dB... not because of dogma, but because I can actually hear the difference. I would prefer to cross them lower, but the proof is in the pudding. That clarity and more precise sound was subtle but unmistakable.

If you have the gear to set your slopes and roll off 4th order, then half an octave is absolutely not a concern. But what should be a concern is how the system actually sounds. And many here have said that they actually prefer what they hear with higher XOs: including big towers crossing at 110 or 120. (I'm not that extreme! :p ...but that should just further illustrate the Mileage Factor!)

:)

I liked the Martin Logan Motion series when I auditioned the 60XT... I didn't have them in my own room though, so we were listening at a dealer room, probably full range. Good speakers, but overpriced, imo. The new XTIs looked pretty cool, as I recall. Would be fun to hear them! :D

Cheers!
First things first : Yes those ML 60XTs are absolutely fantastic ;-) The newer XTis are more of an update to aesthetics is what I understood. At retail , yes they're overpriced, I'd agree.. but after a while, you'd forget the $$$ ;-)

To be fair , wasnt even paying too much attention to the Polks ;-) , was just using them as an example to make my point using my setup with 24db/octave. Right 12db/Octave is the most common and the general recommendations would apply .

Definitely agree, I'dnt be using them full range , nor was I suggesting to utilize towers full range(LARGE) in general. I have crossed my Focal towers at 80hz too, after trying different XO points +/-..It was just about perfect for me, for movies & music. I do remember the back-forths I had with Ed , years back, when I got the PC13-Ultra from SVS..a monster in all aspects!

Little surprised though with XO of 120hz will Full range towers...I can imagine for the center/surrounds in the HT scenario ...,but for 2 channel music too? . On the other hand, if it sounds good with no localization and clear male dialogue(vs a good Center channel) at 120hz in one's setup, I wont argue with that! To me, 80hz-100hz seems to be the sweet spot ,but like you said YMMV.
I'dnt compromise on the center channel budget though in a HT setup , most important speaker for movie dialogue. Rather not offload some of the dialogue to a sub designed to reproduce bass.

But like you said mileage factor comes into play and how the system actually sounds matter. Just to be clear, I'm not disagreeing or questioning the collective wisdom of this knowlegeable group. It was more of me raising something when I saw "always" , but you clarified it , Cheers!
 
ryanosaur

ryanosaur

Audioholic Ninja
;)
Not to be misquoted... what I said was (format added for emphasis):
I always say start 1 octave above the bottom rated frequency of the speaker. Experiment up and down from there.
No hard fast rules. I just look at:
What can my speaker actually do.​
What does my speaker actually sound good doing.​
Does it make sense.​
Why or why not.​

Too much dogmatic cr@p in the audio world. I definitely don't want to add to it. :D
 
A

AVUser001

Audioholic
;)
Not to be misquoted... what I said was (format added for emphasis):

No hard fast rules. I just look at:
What can my speaker actually do.​
What does my speaker actually sound good doing.​
Does it make sense.​
Why or why not.​
Maybe I jumped the gun ;-). Thanks for the clarification..
 
Pogre

Pogre

Audioholic Spartan
I have full range speakers (+/- 3 dB to 30 hz) and I'm using 120 hz for a crossover point. I'd rather that be lower but given my room modes a higher crossover just measures and sounds better. My subs are both up front with my towers so localization isn't an issue.
 

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