# Crossover Suggestions, Please...



## Osage_Winter (Apr 8, 2010)

Greetings.

Recently replaced my Polk R20 bookshelves with RTi12's for the left and right mains in the HT system (the R20's have taken a "backup" role in my two channel rig for now), primarily for a new house we moved into. Also in the system are a CSi30 center, PSW350 sub and SpeakerCraft in-ceilings which were preinstalled when we moved in; I'm using those for surrounds.

The problem is, after running my Onkyo 605's Audyssey auto set up, the system pegged the RTi12's as "Full Range" which ordinarily they would be due to their sheer size and power handling, but in my setup, I'd like to get as much stress off the receiver as possible so I want to have all channels crossed over to the sub. Onkyo implements a setup whereby Audyssey indentifies certain channels, based on certain characteristics, as "Large" or "Full Range," which I understand...the auto setup routine also found my center needing to roll off at "80Hz" and the in ceiling surrounds to be "Full Range" as well. The next time I used Audyssey the next evening, the results were different -- the system found the RTi12's as Full Range, but it also found the CSi30 center and the surrounds as Full Range as well...

This is beginning to confuse me and is getting a bit daunting; I was told, because the Polk RTi12's can flex some low-end muscle on their own, to set the RTi12's to 60Hz in the receiver, and whatever I want for the others. But is this correct? What would be the suggested crossover for a Polk CSi30 center and SpeakerCraft in-ceiling surrounds...can I leave these on 80 as well?

And what about the suggestion of leaving the RTi12's at 60Hz so they can play some of their bass, but also feed ultra-low signals to the sub...is that OK?

If anyone can lend any advice, I'd appreciate it!


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## Jungle Jack (Jul 28, 2009)

Hello,
Cross everything over to 80 Hz. Audyssey often selects Full Range for Speakers. However, especially with your AVR, 80 Hz is absolutely the way to go for all channels.

Audyssey actually recommends that all Speakers regardless of size be crossed over at 80 Hz. By doing so, more processing power is applied to the Subwoofer Channel. Moreover, THX advocates an 80 Hz Crossover as well.

I personally crossover all of my Speakers to 80 Hz even though the Front and Surrounds are capable of going down to around 30 Hz and I have high powered outboard amplifiers. A major part of this is often the best place for Speakers to be placed is often not the best place for a Subwoofer to be placed.
Cheers,
JJ


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## Osage_Winter (Apr 8, 2010)

Jungle Jack said:


> Hello,
> Cross everything over to 80 Hz. Audyssey often selects Full Range for Speakers. However, especially with your AVR, 80 Hz is absolutely the way to go for all channels.
> 
> Audyssey actually recommends that all Speakers regardless of size be crossed over at 80 Hz. By doing so, more processing power is applied to the Subwoofer Channel. Moreover, THX advocates an 80 Hz Crossover as well.
> ...


As Always, JJ...Thank You!

My initial feeling was to cross everything over at 80Hz as well, but I wasn't positive for the smallish in-ceiling surrounds or the CSi30 center...

Are you sure the center and surrounds would be OK with an 80Hz crossover?

Futhermore, what about the rather large tower RTi12's being set to 60 as a suggestion I received...I was told that by setting these floorstanding towers to 60Hz, they can flex some muscle while also feeding low information to the sub...do you agree?


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## Jungle Jack (Jul 28, 2009)

Hello,
I would still use 80 Hz for all channels even though the Rti 12 is capable of going lower. The TX-SR605 while a fantastic value, will sound its best being relieved of playing below 80 Hz.

Your CC should be fine at 80 Hz, but I am not that familiar with Polk's Range. Especially since Audyssey chose 80 Hz for your CC and since Audyssey said your Surrounds could be full range, there should be no problem there.
Cheers,
JJ


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## lsiberian (Mar 24, 2009)

amp stress depends only on the requested power, phase and impedance curves of individual driver in question. Going full range would likely not cause any harm to the amp. However crossing below 80hz is illogical because perceptual research has shown that at 80hz bass is non directional. 

Auddysey good for correcting some speaker issue, but not for setting up the range of your speakers. Set them to 80hz and you will be fine.


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## Jungle Jack (Jul 28, 2009)

lsiberian said:


> amp stress depends only on the requested power, phase and impedance curves of individual driver in question. Going full range would likely not cause any harm to the amp. However crossing below 80hz is illogical because perceptual research has shown that at 80hz bass is non directional.
> 
> Auddysey good for correcting some speaker issue, but not for setting up the range of your speakers. Set them to 80hz and you will be fine.


Hello,
I agree with all of that. I do maintain you would have more headroom for the Polk's and Speakercraft if going with an 80 Hz Crossover. Especially if choosing to playback at or near Reference Levels. I definitely agree that it would not cause damage to the 605 if set to full range. I just think the Subwoofer is best tasked with reproducing all frequencies below 80 Hz which we both agree on.
Cheers,
JJ


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## Osage_Winter (Apr 8, 2010)

Jungle Jack said:


> Hello,
> I would still use 80 Hz for all channels even though the Rti 12 is capable of going lower. The TX-SR605 while a fantastic value, will sound its best being relieved of playing below 80 Hz.


Okay. I understand, and have definitely taken this into advisement -- thank you. There's a small part of me, though, as I have been discussing with glaufman in the subwoofers section, that feels like the bass capabilities of the RTi12's are kind of being "robbed" by leaving these on an 80Hz rolloff; I wish I could find a setting that allows these big speakers to flex a bit of their woofer muscle WHILE sending ultra-low frequencies to the sub...do you still recommend only 80Hz?



> Your CC should be fine at 80 Hz, but I am not that familiar with Polk's Range. Especially since Audyssey chose 80 Hz for your CC and since Audyssey said your Surrounds could be full range, there should be no problem there.
> Cheers,
> JJ


Thanks, once more. The problem is, Audyssey changed its mind the second running of the calibration; it pegged both the center and surrounds as full range, but the night before, it claimed the center should be rolled off at 80Hz and the surrounds at full range, if I am not mistaken...

Is it safe to simply keep all these speakers at 80Hz?


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## Osage_Winter (Apr 8, 2010)

lsiberian said:


> amp stress depends only on the requested power, phase and impedance curves of individual driver in question. Going full range would likely not cause any harm to the amp. However crossing below 80hz is illogical because perceptual research has shown that at 80hz bass is non directional.


Thanks lsiberian.

I do believe, though, that "over stressing" an AVR like the Onkyo 605 in question, especially when connected to power pig mains like my Polk RTi12's, really does come into play if the receiver is asked to play these full range; I've always heard that the receiver will be asked to do a lot more by driving speakers (like these) in a full range configuration, whereby crossing them over will relieve a great deal of the "work load" it needs to perform -- hence more (perceived?) power for mid and upper performance, and cleaner dynamics. 



> Auddysey good for correcting some speaker issue, but not for setting up the range of your speakers. Set them to 80hz and you will be fine.


After running Audyssey a few times, I really didn't like the way it sounded especially with its post-applied EQ curve, so I just set the trims to my taste and turned the EQ off; that said, I still don't understand why it's not advised to let the 12's have some "breathing room" with a 60Hz crossover, so it can utilize a bit of its woofer abilities while sending ultra-low frequencies to the sub...is it because of the non directional factor you cite at 60Hz?


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## Osage_Winter (Apr 8, 2010)

Jungle Jack said:


> Hello,
> I agree with all of that. I do maintain you would have more headroom for the Polk's and Speakercraft if going with an 80 Hz Crossover. Especially if choosing to playback at or near Reference Levels. I definitely agree that it would not cause damage to the 605 if set to full range. I just think the Subwoofer is best tasked with reproducing all frequencies below 80 Hz which we both agree on.
> Cheers,
> JJ


JJ,

I just don't feel comfortable running this relatively low powered receiver full range into the massive towers that are the Polk RTi12's; it just seems that it would be asking the receiver to do too much...plus, I do have a subwoofer in the system, so it makes sense to cross these over.

At any rate, I just want to make sure the center and surrounds are OK on an 80Hz rolloff; I cannot find any specs to suggest a crossover for these...


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## Jungle Jack (Jul 28, 2009)

Hello,
There is definitely no problem with crossing over your CSi 30 at 80 Hz as it rated down to around 60 Hz.
I am not positive about your Surrounds, but if Audyssey said "Full Range", you should be golden at 80 Hz.
Cheers,
JJ


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## Osage_Winter (Apr 8, 2010)

Jungle Jack said:


> Hello,
> There is definitely no problem with crossing over your CSi 30 at 80 Hz as it rated down to around 60 Hz.
> I am not positive about your Surrounds, but if Audyssey said "Full Range", you should be golden at 80 Hz.
> Cheers,
> JJ


So shouldn't the center cross over at 60 then too?


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## Jungle Jack (Jul 28, 2009)

Osage_Winter said:


> So shouldn't the center cross over at 60 then too?


Hello,
No. Everything should be crossed over at 80 Hz. Your Center Channel might be rated down to 60 Hz, but your Subwoofer is best left to handle this frequency. And again, this will give more power to your Center Channel and the rest of your Speakers.

I suppose in the end, you should experiment and trust your ears. Again, I have Speakers that play down to 30 Hz and still crossover at 80 Hz on all channels. With your AVR not having a huge power supply, I really think your best bet will be to use 80 Hz as THX, Audyssey, and most others advocate. However, it goes without saying that the decision is yours.

Understand that 80 Hz is not high a frequency as you might think. Those tiny Satellite Speakers like Polk's budget 5.1 Package have to be crossed over at 150 Hz and higher.
Cheers,
JJ


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## tonyvdb (Sep 5, 2007)

Crossovers are not a brick wall as far as a cutoff is concerned its more like a slope. If you use an 80Hz crossover there is still a fair amount of lower and higher frequencies getting past it usually down to about 45Hz before its gone and again above till about 110Hz.


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## Osage_Winter (Apr 8, 2010)

Thank you, guys. I appreciate the continued help. 

So, here's my speaker setup as seen in the AVR's setup menu:

*Subwoofer: YES
Front: 60Hz
Center: 80Hz
Surrounds: 80Hz
Surround Back: NONE
Low Pass Filter of LFE: 120Hz*

I am leaving the Polk RTi12's at "60Hz" for now, as I think I am going to follow the advice I received from someone that had some experience with Polk towers that suggested to me 60 may allow these large floorstanders to flex a bit of their "bass muscle" while still allowing the sub to handle below-60Hz frequencies.

Is this okay? :huh:


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## tonyvdb (Sep 5, 2007)

There is nothing wrong with having a 60Hz crossover for the mains however it will put more stress on your receivers amp and this is why its better to set it for 80Hz and have the subs amp take the load that it is designed for. But in the end its up to you and what you think sound best to your ears.


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## Osage_Winter (Apr 8, 2010)

tonyvdb said:


> There is nothing wrong with having a 60Hz crossover for the mains however it will put more stress on your receivers amp and this is why its better to set it for 80Hz and have the subs amp take the load that it is designed for. But in the end its up to you and what you think sound best to your ears.


Thanks, Tony.

But does my philosophy, at least, in terms of letting such big speakers do some woofer work, make sense? Will dropping the fronts to 60 actually _allow_ the RTi12's to play a bit deeper?


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## tonyvdb (Sep 5, 2007)

Osage_Winter said:


> Thanks, Tony.
> Will dropping the fronts to 60 actually _allow_ the RTi12's to play a bit deeper?


Yes, it will send more lows to the speakers, I understand your thoughts as my mains also play quite low (down to 36Hz) and for two channel listening this is my preference but movies I really prefer leaving things all at 80Hz even though all my speakers even the surrounds can play much lower.


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## Osage_Winter (Apr 8, 2010)

tonyvdb said:


> Yes, it will send more lows to the speakers, I understand your thoughts as my mains also play quite low (down to 36Hz) and for two channel listening this is my preference but movies I really prefer leaving things all at 80Hz even though all my speakers even the surrounds can play much lower.


Thank you very much, my friend. :bigsmile:


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## JCD (Apr 20, 2006)

Osage_Winter said:


> Thanks, Tony.
> 
> But does my philosophy, at least, in terms of letting such big speakers do some woofer work, make sense? Will dropping the fronts to 60 actually _allow_ the RTi12's to play a bit deeper?


Sorry for jumping in, but I wanted to throw in my $0.02..

I'd first try listening to both crossovers and deciding which sounds best.

On a theoretical level, I would choose 80hz. My thinking is that the harder a speaker has to work, the more likely it's going to distort, and although your speakers may be rated to go lower, they will still have to work harder to get there.

Again, just my $0.02.


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## Jungle Jack (Jul 28, 2009)

Hello,
I totally agree with that. Tis why I posted that he should trust his ears. With the TX-SR605 not being a powerhouse, I definitely am inclined to go with a 80 Hz crossover. I use very high power/current Amplifiers and Speakers that will play down to 30-35 Hz Front and Rear and still crossover at 80 Hz.

Much of this is because with Audyssey's MultEQ XT, when all Speakers are set to Small, over 8 times to filtering power goes to the critical Subwoofer Channel. Moreover, I adore my Subwoofer and truly think it is best handling all frequencies below 80 Hz. Moreover, many A/V Professionals believe that only Speakers that can play down to 20 Hz with meaningful output (unbelievably few Speakers that do) should be set to Full Range.
This Article also further convinced me in the logic of a 80 Hz universal crossover:http://www.hometheaterhifi.com/tech...lings-on-subwoofer-crossover-frequencies.html
Cheers,
JJ


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## Osage_Winter (Apr 8, 2010)

JCD said:


> Sorry for jumping in, but I wanted to throw in my $0.02..
> 
> I'd first try listening to both crossovers and deciding which sounds best.
> 
> ...


Thank you, JCD! 

No problem about chiming in; I appreciate the input and suggestions!

I understand your theory regarding 80Hz, as I do Jungle Jack's and everyone else's; I have been running my RTi12's at 60, per someone's suggestion over on the Polk Forums, and haven't had any problems so far, but I suspect I am going to return to 80, as recommended, at some point. 

I will report back with any changes.


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## Osage_Winter (Apr 8, 2010)

Jungle Jack said:


> Hello,
> I totally agree with that. Tis why I posted that he should trust his ears. With the TX-SR605 not being a powerhouse, I definitely am inclined to go with a 80 Hz crossover. I use very high power/current Amplifiers and Speakers that will play down to 30-35 Hz Front and Rear and still crossover at 80 Hz.


I understand, Jack. Thank you for your continued support.

I think, though, that you should give the 605 a bit more credit than it normally receives (no pun intended); I completely understand you're running high current/high powered stuff in your rig, but this "90 watt per channel" amp inside this thing (the 605, and its "rated" power) isn't really that muscle-less as everyone thinks. It can whoop some serious behind when called upon to do so -- but I understand what you're saying about the 80Hz thing. :yes:



> Much of this is because with Audyssey's MultEQ XT, when all Speakers are set to Small, over 8 times to filtering power goes to the critical Subwoofer Channel. Moreover, I adore my Subwoofer and truly think it is best handling all frequencies below 80 Hz. Moreover, many A/V Professionals believe that only Speakers that can play down to 20 Hz with meaningful output (unbelievably few Speakers that do) should be set to Full Range.
> This Article also further convinced me in the logic of a 80 Hz universal crossover:http://www.hometheaterhifi.com/tech...lings-on-subwoofer-crossover-frequencies.html
> Cheers,
> JJ


I completely get this; makes sense. But what about those who _don't_ run Audyssey in the AVR...are we still getting "over eight times the filtering power" to the sub by keeping the speakers off of "Full Range" and crossed over at some value?


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## Jungle Jack (Jul 28, 2009)

Hello,
Orange, I truly think the TX-SR605 is a stunning value. It is just that even the TX-SR706 drops to the 70 Watt range when 5 channels are driven and your Polk RTi12's are fairly large. My apologies if offended by saying it is not a powerhouse. I really was trying to make the point that even with 350 WPC outboard Amplifiers on the Fronts, I still crossover at 80 Hz.
Cheers,
JJ


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## Osage_Winter (Apr 8, 2010)

Jungle Jack said:


> Hello,
> Orange, I truly think the TX-SR605 is a stunning value. It is just that even the TX-SR706 drops to the 70 Watt range when 5 channels are driven and your Polk RTi12's are fairly large. My apologies if offended by saying it is not a powerhouse. I really was trying to make the point that even with 350 WPC outboard Amplifiers on the Fronts, I still crossover at 80 Hz.
> Cheers,
> JJ


Jack,

That's _Osage_ not "Orange".....:wave: :T

Just messin' around...

But, no, I completely get what you're saying and understand your point -- absolutely no offense taken here. I was just pointing out that this model gets a bad rap everywhere and it's really not as weak of an amp as it's touted to be. But that's besides the point, you're right -- your point was that even with your high current gear, you're crossing over at 80Hz. I understand.

That's disappointing about the 706's drop in power -- it's unfortunate because that looks like a very nice unit. At any rate, my initial concern revolved around the issue of not clipping the amp, but getting some more "punch" out of the RTi12's because they seem like the can do some serious damage, bass wise -- I didn't want to "rob" the speakers of this ability, but on the other hand, I'm kind of in a Pandora's Box because my AVR isn't up to the task of driving towers that large. Forget about Full Range, which is totally out of the question -- but apparently even for a 60Hz rolloff...:rant: :crying: :foottap: :hissyfit:


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## Jungle Jack (Jul 28, 2009)

Hello,
Osage, that was actually my spell check that I did not even notice before posting in respect to your User Name. Should have done better proof reading.

Again, experiment and find what sounds best to you. While I might prefer 80 Hz for best results, you might not. Again, trust your Ears. You have some very nice front Speakers and I totally understand wanting to get the most out of them.
Cheers,
JJ


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## Osage_Winter (Apr 8, 2010)

Jungle Jack said:


> Hello,
> Osage, that was actually my spell check that I did not even notice before posting in respect to your User Name. Should have done better proof reading.


No problem -- I was just yankin' ya chain. 



> Again, experiment and find what sounds best to you. While I might prefer 80 Hz for best results, you might not. Again, trust your Ears. You have some very nice front Speakers and I totally understand wanting to get the most out of them.
> Cheers,
> JJ


Exactly my sentiment -- I'd like to get at least some kind of performance out of the 12's while I still am driving them with the 605. Of course, down the road, I will add a killer three or five channel power amp to the system, with a new AVR with pre outs, so I can drive these RTi12's with better and more appropriate power. 

But at least you can put my mind at ease regarding the 60Hz setting allowing the RTi12's to play a bit lower, yes?

If I hear any issues with this, after doing some demo crank-up sessions, I will report back and switch to 80...


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## Jungle Jack (Jul 28, 2009)

Osage_Winter said:


> No problem -- I was just yankin' ya chain.
> 
> 
> 
> ...


Hello,
Osage, it might not be an issue with clipping so much as an issue of cascading crossovers. That is having different crossover frequencies on your Front Stage (Rti12'a and Center Channel). Check out the Secrets of Home Theater and High Fidelity link I posted for more about this issue.
Cheers,
JJ


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## Osage_Winter (Apr 8, 2010)

Jungle Jack said:


> Hello,
> Osage, it might not be an issue with clipping so much as an issue of cascading crossovers. That is having different crossover frequencies on your Front Stage (Rti12'a and Center Channel). Check out the Secrets of Home Theater and High Fidelity link I posted for more about this issue.
> Cheers,
> JJ


I gotcha. I will look that over just as soon as I can...

In the meantime, are you certain my in-ceiling surrounds shouldn't be at a higher crossover, like, say, 100 or so? Should the center and surrounds be on an 80Hz rolloff? It seems a bit weird for the surrounds because they're circular in-ceiling SpeakerCrafts that are pretty small in dimension...

What do you think?


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