# Center and Surrounds Crossover Suggestions...



## Osage_Winter (Apr 8, 2010)

I have settled on a 60Hz crossover for my Polk RTi12 mains because they're so large as I would like to utilize some of their punch along with my sub, but I'm still getting stuck on what would sound best for my CSi30 center and the SpeakerCraft in-ceiling surrounds; right now, I'm keeping the center and surrounds on an 80Hz crossover, but since I do not know the model of in-ceiling SpeakerCraft speakers that are in my theater room's ceiling (the house had them pre-installed), I don't know what the "better" crossover would be for these.

I'm assuming 80Hz (as it's specified by THX) is okay for the Polk CSi30 center as that speaker can put out a good deal of punch for effects and such; but with the SpeakerCraft surrounds, the 80Hz setting seems to be a bit too low for these; unless my ears are tricking me, I believe I can sense some "crackly" characteristics coming from them (the system is calibrated and isn't distorting in any other way) which is leading me to think they're taking on too much sonic information. Should these in-ceiling surrounds be raised to a 100 or higher crossover? Is there a "set standard" for in-wall or in-ceiling speakers when it comes to crossover points?


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## recruit (May 9, 2009)

TBH - I would just set every speaker for movies/multichannel music to 80hz and then when listening to 2 channel just use the pure direct mode which will allow full bandwidth for stereo replay.


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## tonyvdb (Sep 5, 2007)

80Hz seems about right, There is not a whole bunch of movies that really use the surround channels full range capabilities particularly below 50Hz so I would not be too concerned about it.


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## Osage_Winter (Apr 8, 2010)

Thank You Guys...

Appreciate the input. 

The issue I'm "debating" is more with regard to the 80Hz crossover spec being used for the in-ceiling SpeakerCrafts I am running, as I don't know their technical limits and I am thinking that perhaps there's too much sonic information getting to them at an 80Hz setting -- hence, why I'm asking if perhaps 100 or higher should be used for the surrounds.

Tony -- I completely understand and agree with what you're saying with regard to the surrounds and what they're utilized for and such, but what I'm trying to ascertain is if TOO much low-end is getting to my in-ceilings with an 80Hz crossover and perhaps this should be raised...


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## recruit (May 9, 2009)

There is no harm in trying different crossovers for the rears but tbh I do not think you will notice much difference between 80hz and 100hz...


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## eugovector (Sep 4, 2006)

What's the frequency response specs on the speakercraft in-ceilings?


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## bambino (Feb 21, 2010)

Rule of thumb. Go by the size of the diriver.


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## Osage_Winter (Apr 8, 2010)

recruit said:


> There is no harm in trying different crossovers for the rears but tbh I do not think you will notice much difference between 80hz and 100hz...


Thank you for your thoughts here, recruit.


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## Osage_Winter (Apr 8, 2010)

Bambino and 'Vector:

Thank you for your input; I am uncertain of the technical specs of the SpeakerCrafts, as they were pre-installed with my house we recently purchased. I was trying to ascertain if there's a certain "standard" that can be followed, or suggested, in terms of in-wall or in-ceiling speakers and their crossover points...I am not sure if 80Hz is "too low" for speakers such as these...


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## eugovector (Sep 4, 2006)

If you don't know the model of the speakers, follow Bambino's advice and go by the size of the driver. I'd go:

<4" = 150-200HZ
4-6" = 120-100
6-8" = 80hz


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## Osage_Winter (Apr 8, 2010)

I am technically unaware of the size of these speakers' drivers, either; I suppose what I am going to have to do is ply the ceiling grilles off these things and look...

Can either of you give me some insight by glancing at some of their models here:

www.speakercraft.com ?

My models have to be part of the AIM family, as an installer that assisted me with wiring these mentioned they were pivoting in structure, and that they were definitely SpeakerCrafts...based on this, is there any way to guess at a decent crossover?


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## recruit (May 9, 2009)

Unless you know the exact model number it is hard to say what they suggest what the xover should be, but general listening at moderate levels should be sufficient to tell you whether you are driving them too hard at say 80hz, I had a quick look at the website you posted and the AIM range is quite large...


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## Osage_Winter (Apr 8, 2010)

Oh well,

Thanks, though, John!


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## bambino (Feb 21, 2010)

I know first hand that taking the gills off of inwalls or ceiling speakers can be a trick because you don't want to mess it up for cosmetic reasons. Maybe if you try to look through the grill with a flashlight it might give you a general idea of what size the driver is, otherwise i'd just go with an 80 to 100hz crossover and see how they play, my guess is that they are probly 6'' to 8'' drivers and in that case you should be fine with the frequencys specified here.


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## Osage_Winter (Apr 8, 2010)

bambino said:


> I know first hand that taking the gills off of inwalls or ceiling speakers can be a trick because you don't want to mess it up for cosmetic reasons.


Precisely...



> Maybe if you try to look through the grill with a flashlight it might give you a general idea of what size the driver is, otherwise i'd just go with an 80 to 100hz crossover and see how they play, my guess is that they are probly 6'' to 8'' drivers and in that case you should be fine with the frequencys specified here.


Thank you; when you say "specified here," do you mean the 80 or 100Hz suggestions?


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## bambino (Feb 21, 2010)

Osage_Winter said:


> Precisely...
> 
> 
> 
> Thank you; when you say "specified here," do you mean the 80 or 100Hz suggestions?


Yes, that is where i'd start. :T


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## Osage_Winter (Apr 8, 2010)

bambino said:


> Yes, that is where i'd start. :T


Thanks Bambino...

I pretty much figured it would be 80 or possibly 100 for these in-ceiling speakers, but it could possibly be even higher...

You seem to know more than you hinted at when we first started discussing HT upon my arrival on the site...remember? You had asked questions pertaining to a receiver I believe, and mentioned that I "seem to know my stuff" as you put it -- but I must say, you are quite knowledgeable yourself! :bigsmile:


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## bambino (Feb 21, 2010)

Osage_Winter said:


> Thanks Bambino...
> 
> I pretty much figured it would be 80 or possibly 100 for these in-ceiling speakers, but it could possibly be even higher...
> 
> You seem to know more than you hinted at when we first started discussing HT upon my arrival on the site...remember? You had asked questions pertaining to a receiver I believe, and mentioned that I "seem to know my stuff" as you put it -- but I must say, you are quite knowledgeable yourself! :bigsmile:


Thanks for the kind words and i'm glad i could help. :sn:


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## mdrake (Jan 31, 2008)

You could measure them with REW to get an idea of where they roll off and cross them over from that point on up. 

Matt


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## Osage_Winter (Apr 8, 2010)

Okay, so can we all agree at least that for my Polk CSi30 center, an 80Hz crossover is right?


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## bambino (Feb 21, 2010)

Osage_Winter said:


> Okay, so can we all agree at least that for my Polk CSi30 center, an 80Hz crossover is right?


With me not being familiar to that speaker i would still say yes. 80hz is a fairly high frequency in terms of the intended uses for it (center channel). You'll be fine.:T


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## mdrake (Jan 31, 2008)

bambino said:


> With me not being familiar to that speaker i would still say yes. 80hz is a fairly high frequency in terms of the intended uses for it (center channel). You'll be fine.:T


Dito and I looked up the center, 80hz should be no problem. 

From Here http://www.polkaudio.com/homeaudio/specs/recent/csi30/
*Electrical
Overall Frequency Response	52Hz-27kHz
Lower -3dB Limit	55Hz
Upper -3dB Limit	26kHz*


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## Osage_Winter (Apr 8, 2010)

Thanks A Lot Guys!

Matt, appreciate the link and research info; thank you.

Can you explain to me how it's established that 80Hz is an "okay" setting based on the frequency specs Polk provides? Just trying to get a grip on how it all works...:T


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## eugovector (Sep 4, 2006)

Setting the crossover at 80hz means that frequencies set to that speaker will start to slope off starting at 80HZ. Because that speaker is rated to play as low as 55, you'll be fine.

I use the rule of thumb that if the speaker can play 10hz below the crossover point, you'll be fine.


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## Osage_Winter (Apr 8, 2010)

Thanks, Vector.

Are we sure, then, that perhaps the CSi30 shouldn't be set to something lower than 80?


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## eugovector (Sep 4, 2006)

80HZ is the THX standard and even budget subs will outperform more expensive main speakers from 80-hz down.


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## Osage_Winter (Apr 8, 2010)

Gotcha.

Is it okay, however, to leave my rather large Polk RTi12 mains on a 60Hz crossover point, being that I want to get some low end from them?


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## eugovector (Sep 4, 2006)

If you have a quality sub, it's my opinion, shared by THX, that you should cross even large towers over at 80hz. Yes, this stings if you bought large towers for their increased bass output only to send said bass to the sub, but look at it this way, at least you don't have to buy speaker stands.


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## Jungle Jack (Jul 28, 2009)

Osage_Winter said:


> Gotcha.
> 
> Is it okay, however, to leave my rather large Polk RTi12 mains on a 60Hz crossover point, being that I want to get some low end from them?


Hello,
It is best to experiment. I will say that even though all of my Speakers go far below 80 Hz, I have all Speakers crossed at 80Hz. Keep in mind that 80 Hz might be lower than you presume it to be. Also, even though a Speaker is crossed over at 80 Hz, it is not a Brick Wall.

The best part about using 80 Hz is that is gives extra headroom to your Amplifier/AVR to focus all frequencies above 80 Hz. Moreover, the best place Acoustically for Speakers is almost never the best place for the Subwoofer.
Cheers,
JJ


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## Osage_Winter (Apr 8, 2010)

eugovector said:


> If you have a quality sub, it's my opinion, shared by THX, that you should cross even large towers over at 80hz. Yes, this stings if you bought large towers for their increased bass output only to send said bass to the sub, but look at it this way, at least you don't have to buy speaker stands.


I understand the THX reference is 80Hz, but I do not have a quality sub, and I didn't really buy the RTi12s for their bass response -- it's just that I wanted larger towers for the bigger room the HT is in within this new house and didn't want to deal with speaker stands, as you pointed out ironically. 

But a member over at the Polk forums advised me to use the 60Hz crossover, claiming that at 60, this would allow the RTi12's to "flex a bit more of their muscle" while sending everything below 60 to the sub; I have also read that some recommend very large towers to be crossed over at 60.


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## Osage_Winter (Apr 8, 2010)

Jungle Jack said:


> Hello,
> It is best to experiment. I will say that even though all of my Speakers go far below 80 Hz, I have all Speakers crossed at 80Hz. Keep in mind that 80 Hz might be lower than you presume it to be. Also, even though a Speaker is crossed over at 80 Hz, it is not a Brick Wall.


Hi Jack; I think you actually explained this one to me before. It's just that, as I said in the above reply, I was advised by a Polk forum member to try 60, as this would allow the towers to provide a bit more punch while also feeding below 60Hz signals to the sub; I'm just not sure where the best position is. 



> The best part about using 80 Hz is that is gives extra headroom to your Amplifier/AVR to focus all frequencies above 80 Hz.


This is completely understandable and I agree wholeheartedly; before getting these RTi12s, I was running Polk R20 bookshelves on stands, and always kept the crossover at 80Hz for the exact reasons you specify here...



> Moreover, the best place Acoustically for Speakers is almost never the best place for the Subwoofer.
> Cheers,
> JJ


But how does this come into play with the crossover settings?

You know, it's strange; you recommended trying different settings and experimenting in your first statement, and I believe that's what I am going to have to do because I can swear since I switched the mains to 60Hz, I have been getting _less_ bass and less "tactile slam" from my PSW30 sub compared to even before I got the RTi12s...it's like there's just something "off" with the 60Hz setting, and I don't know what; like the mains aren't "blending" with the sub right...

Does this make any sense? :rubeyes: :blink: onder: :scratch: :dumbcrazy: onder: :unbelievable: :unbelievable:


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## recruit (May 9, 2009)

It's all about integration and getting the set up right, if a sub does not sound as good then I would look at changing the settings until it sounds good enough, experiment !


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## Osage_Winter (Apr 8, 2010)

recruit said:


> It's all about integration and getting the set up right, if a sub does not sound as good then I would look at changing the settings until it sounds good enough, experiment !


John,

I shall have to experiment, it seems. But I'm wondering, does it sound "normal" in the least sense that a 60Hz crossover seems to be "robbing" the bass from the sub? That is, because my mains are set to 60, something just doesn't seem to be "blending" right?


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## bambino (Feb 21, 2010)

Osage_Winter said:


> John,
> 
> I shall have to experiment, it seems. But I'm wondering, does it sound "normal" in the least sense that a 60Hz crossover seems to be "robbing" the bass from the sub? That is, because my mains are set to 60, something just doesn't seem to be "blending" right?


I'm sure your not robbing the sub of bass, you may have some sort of cancelation going on :huh:. My mains and center are set at 40hz and sub crossed at 100hz and have had no issues with blending but i may just be lucky that everything is playing well together. My thoughts are try relocating the sub and maybe repositioning the mains. Hope this helps, it seems to me that you have everything right. :T Oh, and as john says experiment.


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## Osage_Winter (Apr 8, 2010)

Thank you, Bambino. It's probably this: 



> I'm sure your not robbing the sub of bass, you may have some sort of cancelation going on





> My mains and center are set at 40hz and sub crossed at 100hz


Wow -- 40 is pretty low; do you not believe in the 80Hz THX spec? Also, I've been advised that "120Hz" is the best setting for the sub low pass filter (inside the processor or AVR) as that will allow the maximum passthrough of bass from a signal; the LFE channel brickwalls at 120Hz, so you won't lose any LFE at this setting. Try that out. 



> My thoughts are try relocating the sub and maybe repositioning the mains. Hope this helps, it seems to me that you have everything right. :T Oh, and as john says experiment.


Thanks Bambino; I have tried relocating the sub to directly into the corner, firing into the corner directly, and that just seemed to make everything a bit boomier -- right now, it's sitting to the direct left of my left main channel along the main wall. As for the mains, they're flush against the wall unit, flanking the display, so maybe I need to experiment with some toe-in...


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## bambino (Feb 21, 2010)

Osage_Winter said:


> Thank you, Bambino. It's probably this:
> 
> 
> 
> ...


No i don't go by what THX tells me i go by what my ears tell me. The way i figure it is that my mains will pick up where the sub drops off and like i said before is the sub and mains seem to play very well together, to me my system sounds awesome! Corner loading your sub will definatly make it boomier and as far as your mains try moving them out from the wall a bit and play around with that sub location too. Hope this helps. :sn::T


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## Osage_Winter (Apr 8, 2010)

The mains have been pulled off the wall a good ways; not too far, but they're not against the main front wall at all.


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## Jungle Jack (Jul 28, 2009)

Hello,
Again, my main and first point was to experiment and trust your ears in respect to where is the best place to crossover your Mains. I will point out again that the best place to setup Speakers is often one of the worst to setup your Subwoofer. It is this rationale that leads me to use an 80 Hz Crossover on all Speakers. Results may vary.
Cheers,
JJ


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## Osage_Winter (Apr 8, 2010)

Jungle Jack said:


> Hello,
> Again, my main and first point was to experiment and trust your ears in respect to where is the best place to crossover your Mains. I will point out again that the best place to setup Speakers is often one of the worst to setup your Subwoofer. It is this rationale that leads me to use an 80 Hz Crossover on all Speakers. Results may vary.
> Cheers,
> JJ


Thanks Jack,

So, do I understand that because my sub is set up very much near, or like, the main speakers, this could be a reason I may be hearing some cancellation effect with the bass? Is this why you would suggest -- not set in stone of course as you pointed out that our ears are the best judges and results will vary -- crossing the speakers over at 80Hz regardless of sheer size and bass capabilities? Should I, in theory, experience more smooth transitions? 

Right now, something just sounds...well.."off" in that the sub and the mains seem to be "competing" for output, unless I am just not hearing it right...:scratch:


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