Convince me that crossover overlap is bad...

[William Lemmerhirt]

Polk LSiM707 Surround Speaker System Page 2

Finally, I did something I usually avoid in speaker reviews: I tried a variety of the manual and automated equalization options available on the Integra pre-pro. I settled on the simplest of tweaks: increasing the pre-pro’s treble control to +1 dB. This raised the measured output of the preamp...

www.soundandvision.com

Lmao!!!!! DSW micropro “subwoofer”.... that’s an oxymoron if I ever heard one. Wtf...
Interesting that the reviewer is basically doing the same as Canuck.

 

[ryanosaur]

At the same time, transferring some of the more power-demanding low frequency content to the specialized Subwoofer will also help your tower perform better by using energy more efficiently. Most will agree, I think, that with the appropriate XO from Speaker to Sub, you will realize more clarity in your Mids and Highs, as well as better bass from the Sub.
Another note with the Polks is that they have an infamous and very demanding Impedance/Phase Angle at the worst possible place a speaker can have this happen: the Low Frequencies. Crossing your towers higher helps the speakers avoid this more 'dangerous' spot of your speaker's design, which at sustained high volume at the right frequency could blow your amps.
***I am not saying it will.
However the Polks are known to drop below 4 ohms with that challenging phase angle. This causes the amps to generate a significant amount of heat which needs to be discharged: something many Amps are not designed for, especially the Amp Stage of an AVR.
Crossing at 80-100 Hz is a common practice and could help you experience both a rise in SQ as well as improve the longevity of your gear!

 

[Crazy Canuck]

Polk LSiM707 Surround Speaker System Page 2

Finally, I did something I usually avoid in speaker reviews: I tried a variety of the manual and automated equalization options available on the Integra pre-pro. I settled on the simplest of tweaks: increasing the pre-pro’s treble control to +1 dB. This raised the measured output of the preamp...

www.soundandvision.com

Wow! How amazingly specific! Thank you sir! Plus I love reading good reviews of speakers I already own...

 

[Crazy Canuck]

At the same time, transferring some of the more power-demanding low frequency content to the specialized Subwoofer will also help your tower perform better by using energy more efficiently. Most will agree, I think, that with the appropriate XO from Speaker to Sub, you will realize more clarity in your Mids and Highs, as well as better bass from the Sub.
Another note with the Polks is that they have an infamous and very demanding Impedance/Phase Angle at the worst possible place a speaker can have this happen: the Low Frequencies. Crossing your towers higher helps the speakers avoid this more 'dangerous' spot of your speaker's design, which at sustained high volume at the right frequency could blow your amps.
***I am not saying it will.
However the Polks are known to drop below 4 ohms with that challenging phase angle. This causes the amps to generate a significant amount of heat which needs to be discharged: something many Amps are not designed for, especially the Amp Stage of an AVR.
Crossing at 80-100 Hz is a common practice and could help you experience both a rise in SQ as well as improve the longevity of your gear!

Thanks for that very detailed response! I should have mentioned I'm going through a Crown XLS 2502, so I'm not concerned about power/headroom.

 

[ryanosaur]

Thanks for that very detailed response! I should have mentioned I'm going through a Crown XLS 2502, so I'm not concerned about power/headroom.

Fair enough.
depending on your usage, I would recommend experimenting with the high XO settings, just from a SQ perspective. See if you hear a difference in the music you listen to.
Training our ears to hear these things can be tricky, but doable if you are interested.
Either way, it is your system, so please enjoy as you see fit!

 

[Crazy Canuck]

Ok last stupid question /clarification (for now) if the Denon is set to LFE+Main, and my front speakers set to "Large" - when I set the LFE+Main to 120hz and the front speaker crossover to 60hz, what is being sent to the subwoofer?
I'm thinking (and wanting it to be) everything from all sources below 120? Thus overlapping 60hz-120hz with the fronts?

 

[lovinthehd]

What do you mean set the LFE+Main to 120hz? You mean the LPF of LFE?

If your speakers are set to large and you're using LFE+Main the crossover set limits where that double bass overlaps...but you're sending a full range signal to the mains and limiting the amount of re-directed/managed bass to the sub by the crossover setting selected.

 

[VMPS-TIII]

The advantage of crossing over the Polks around 80Hz on the receiver is it will reduce bass boom and enhance performance for the Polk speakers at higher volumes. I have large speakers with a 15" woofer and I'm still crossing them over at 80Hz. It offers a cleaner sound in my room when I allow the subs to handle the range below 100Hz.

 

[William Lemmerhirt]

"Large vs Small Subwoofers: Exploring LFE, Main, Double Bass, and More | Subwoofer 101"

Discover the differences between the Large and Small Speaker settings in your AVR, and explore the intricacies of LFE+Main, Double Bass, how crossover works, bass management, and more. Learn how to optimize your audio setup with expert guidance from Subwoofer 101.

subwoofer101.com

I think mostly this guy is a dipshit but this article is interesting. Plus Ed Mullen is the guest star so...

 

[Crazy Canuck]

What do you mean set the LFE+Main to 120hz? You mean the LPF of LFE?

If your speakers are set to large and you're using LFE+Main the crossover set limits where that double bass overlaps...but you're sending a full range signal to the mains and limiting the amount of re-directed/managed bass to the sub by the crossover setting selected.

? What do YOU mean by what do you mean lol
There's a setting choice of either LFE, or LFE+Main - I have it set to LFE+Main
Below that you select a cutoff point - I have it at 120hz
Speakers set to "Large"
Individual crossover for front speakers set to 60hz
I'm guessing you well understand all that, since I'm the one not getting things.

I'm just trying to confirm that the sub is still getting everything up to 120hz, and the fronts everything down to 60hz. Sorry for the continued slowness on my part.

 

[Crazy Canuck]

"Large vs Small Subwoofers: Exploring LFE, Main, Double Bass, and More | Subwoofer 101"

Discover the differences between the Large and Small Speaker settings in your AVR, and explore the intricacies of LFE+Main, Double Bass, how crossover works, bass management, and more. Learn how to optimize your audio setup with expert guidance from Subwoofer 101.

subwoofer101.com

I think mostly this guy is a dipshit but this article is interesting. Plus Ed Mullen is the guest star so...

lol on the dipshit comment - I've thought that about his videos, but that article was pretty good.
But I'm assuming that his and other Denons don't all have the separate/individual crossovers? He says that when you set to large, you automatically get full range - but with my x3600, I'm assuming that even set to Large, because it has a separate individual crossover, that when I select 60hz it still does just that...or does it override the LFE+Main setting of 120hz, and only send frequencies below 60hz to the sub?

 

[lovinthehd]

? What do YOU mean by what do you mean lol
There's a setting choice of either LFE, or LFE+Main - I have it set to LFE+Main
Below that you select a cutoff point - I have it at 120hz
Speakers set to "Large"
Individual crossover for front speakers set to 60hz
I'm guessing you well understand all that, since I'm the one not getting things.

I'm just trying to confirm that the sub is still getting everything up to 120hz, and the fronts everything down to 60hz. Sorry for the continued slowness on my part.

Below what and how is it particularly labeled? On my Denon the choice below selecting LFE vs LFE+Main is the LPF of LFE (i.e. the low pass filter of the LFE channel).

You're basically just running double bass up to 60hz with your settings. If you like it....

 

[ryanosaur]

Speakers set to "Large"

With speakers set to Large, there is no Bass Management and the speakers are receiving full range information. To the best of my knowledge, no XO is applied.
Anybody, is this correct, or no?

 

[EthicalEar]

I'm running a set of Polk LSIM 707's (behind a Crown XLS 2502, behind a Denon X3600)) and an SVS SB-3000. The Polks are good down to 30hz. I've been experimenting with crossover points on the sub and the Polks with overlaps as much as 50hz, and I can't really hear anything unpleasant. Other than the obvious bump in the curve where the overlap is (but I like bass!), what is supposed to be the downside?

The LPF of LFE only affects the LFE content (like a movie's ".1" ch) and is normally set to 120hz, but its not a crossover. A crossover is the point where the low pass and high pass filter slopes cross. When you're setting the speakers to 60hz in the Denon, you're crossing that speaker/channel with the sub. I would not use the low pass filter in the svs (it's not a crossover in your use), that's what's called cascading filters and generally not recommended.

My first day on Audioholics, I have a pair of SVS PB-3000 just a month old and I am experimenting with them the same as Crazy C. Learning from you guys. Thanks!

 

[William Lemmerhirt]

lol on the dipshit comment - I've thought that about his videos, but that article was pretty good.
But I'm assuming that his and other Denons don't all have the separate/individual crossovers? He says that when you set to large, you automatically get full range - but with my x3600, I'm assuming that even set to Large, because it has a separate individual crossover, that when I select 60hz it still does just that...or does it override the LFE+Main setting of 120hz, and only send frequencies below 60hz to the sub?

Well afaik, when you set to large you do get full range, and no option for XO. So I’m not exactly sure if you’re thinking about the LPF of LFE(only affects .1 in movies), or possibly thinking the XO for the other channels is for your mains?
Also afaik, using lfe+mains bypasses any XO, because mains have to be set to large(full range) to use lfe+mains.

 

[lovinthehd]

My first day on Audioholics, I have a pair of SVS PB-3000 just a month old and I am experimenting with them the same as Crazy C. Learning from you guys. Thanks!

Have you checked out articles such as

Home Theater Multiple Subwoofer Set-Up & Calibration Guide

This article discusses methods of proper placement, and setup of multiple subwoofers to achieve the best measurable and audible results for your entire listening area not just a single sweet spot.

www.audioholics.com

 

[William Lemmerhirt]

With speakers set to Large, there is no Bass Management and the speakers are receiving full range information. To the best of my knowledge, no XO is applied.
Anybody, is this correct, or no?

Hi! I did post this below, but yeah, that’s my understanding of lfe+mains.

I’ve never like what it did in my rooms, so I don’t use it.

 

[lovinthehd]

Well afaik, when you set to large you do get full range, and no option for XO. So I’m not exactly sure if you’re thinking about the LPF of LFE(only affects .1 in movies), or possibly thinking the XO for the other channels is for your mains?
Also afaik, using lfe+mains bypasses any XO, because mains have to be set to large(full range) to use lfe+mains.

AFAIK when you set crossovers in such situation as using LFE+Main you limit the range of the overlap via the crossover setting (or if you change speaker to small then that would simply be the crossover).

 

[William Lemmerhirt]

My first day on Audioholics, I have a pair of SVS PB-3000 just a month old and I am experimenting with them the same as Crazy C. Learning from you guys. Thanks!

Hey! Welcome to the rabbit hole!

 

[William Lemmerhirt]

AFAIK when you set crossovers in such situation as using LFE+Main you limit the range of the overlap via the crossover setting (or if you change speaker to small then that would simply be the crossover).

Huh. That’s very interesting if you’re correct. I may have just learned something. I always thought the LFE+mains setting overrode any XO availability since you had to select large for that setting to be active.
Happy to be wrong! Going to RTFM now!!!