Questions About Crossover Points for "R" Series Bookshelves...

Mike LoManaco

Hello, Forum!

I am running a rather dated "R" series bookshelf speaker arrangement powered by an Onkyo TX-SR605 receiver; my questions revolve around the proper crossover points for these speakers. The front mains are larger R20s, while the center is a CSi30 and the surrounds are smaller R15s; the sub is a PSW10. Right now, I have all the speakers in the receiver's configuration menu set to cross over at 80Hz -- the mains, center AND surrounds...

But is this the proper crossover point for all the R series (and CSi center) speakers? Should some of these be at 100Hz or higher?

Any help would be appreciated!

Tim D.

Hi Mike,

For the R15s in the back, I would say either 100Hz or 120Hz. For your R20's and CSi30 I would try either 80Hz or 100Hz. Switch back and forth between the two frequencies on each speaker and see if you can hear a difference, then pick the one that sounds the best to you. Those numbers should give you a starting point.

Tim

Mike LoManaco

Tim D. wrote: »

Hi Mike,

For the R15s in the back, I would say either 100Hz or 120Hz. For your R20's and CSi30 I would try either 80Hz or 100Hz. Switch back and forth between the two frequencies on each speaker and see if you can hear a difference, then pick the one that sounds the best to you. Those numbers should give you a starting point.

Tim

Thanks Tim!

Is there a certain "specification" recommended by Polk for the Rs and CSis? Something I can just "go by"?

comfortablycurt

It's going to depend on several issues, including your specific room, and how your speakers and subwoofer blend together.

There is no specific point that will work best.

In general, the rule of thumb is about 80hz crossover points all around. I wouldn't go as high as 120 unless the speakers weren't capable of reproducing those frequencies. Both of your speakers are capable of reproducing frequencies down to at least 65 hz at -3 Db(give or take for in room extension), so I'd leave them at 80 hz. I've found that crossing them at 100-120 provides a really undesirable emphasis on the upper bass and lower midrange areas.

Mike LoManaco

comfortablycurt wrote: »

It's going to depend on several issues, including your specific room, and how your speakers and subwoofer blend together.

There is no specific point that will work best.

In general, the rule of thumb is about 80hz crossover points all around. I wouldn't go as high as 120 unless the speakers weren't capable of reproducing those frequencies. Both of your speakers are capable of reproducing frequencies down to at least 65 hz at -3 Db(give or take for in room extension), so I'd leave them at 80 hz. I've found that crossing them at 100-120 provides a really undesirable emphasis on the upper bass and lower midrange areas.

Thank you so much for your input!

I figured 80Hz was about right all around (as I constantly hear about THX specifications and such) but I wasn't sure if even the REAR smaller R15s needed to be higher than 80...

So, should I feel comfortable running all the speakers -- the R20 mains, R15 surrounds and CSi center -- at 80Hz? It's okay for the surrounds and center to be crossed over at this point as well?

Again -- thank you SO much for your input.

comfortablycurt

You'll likely be fine running them all at 80. I've found that crossing them over at different points can create gaps in the sound track.

Say that you have your sub and your mains all crossed at 80 hz, with the center and the surrounds crossed at 100hz. If there's supposed to be bass from the surround/center channels in between the 80hz and 100hz crossover points, that part of the soundtrack is going to be missing. With the sub low passed at 80hz and the surrounds high passed at 100hz, the information between the 80hz and 100hz XO points gets left out.

If you have the sub low passed at 80 hz and the surrounds high passed at 80 hz though, you're going to be getting all of the information. Everything down to 80hz will be coming through the surrounds channels, and everything below 80hz will get filtered to the sub, leaving no gaps.

That said, if it seems like the surround channels are rolling off a little prematurely you might want to raise the crossover point to 90hz or so. If that's the case, I'd also raise the sub to 90hz. I doubt you'll run into any issues like that.

I've found that with the sub crossed to high, you get a lot of lower midrange coming through it. There have even been instances during movies where I've heard dialog coming through the sub. I'm speaking of James Earl Jones here. My girlfriend and I were watching The Lion King(go ahead and laugh...lol) a while back, and we couldn't help but crack up because Mufasa's voice(James Earl Jones) was coming through the sub and pounding on the floor...lol

motomech

For me, the biggest variable is how hard am I running the mains?
Since my Monitor 40's are being used near-field(computer desk, 2 ft. from my head), they are under little stress and I leave my Onkyo 504 set to mains/large(no high-pass) with little chance for abusing the woofers.
Correspondingly, I set the reciever's sub X-over at 60hz and avoid most of the boundry problems with the PWS10(not Polk's best product, but the price was right). TSi100's surrounds set to large as well.
To me, this is the best way, but if the distances/spaces were larger, I'm sure I would have to compromise more.

Mike LoManaco

Thanks A lot Guys...

So, would it be safe to just leave all speakers at "80" since I don't drive them that hard; I'm using Polk's PSW10 sub?

comfortablycurt

Yes, it will be perfectly safe.

You're speakers are rated for frequency ranges extending well below 80hz. Even if they weren't, it wouldn't hurt them. The woofers would just be rolling off before the XO point. I very highly doubt you'll have that problem though.

Mike LoManaco

comfortablycurt wrote: »

Yes, it will be perfectly safe.

You're speakers are rated for frequency ranges extending well below 80hz. Even if they weren't, it wouldn't hurt them. The woofers would just be rolling off before the XO point. I very highly doubt you'll have that problem though.

Thanks, As Always, Curt...

But which speakers are you referring to that have an extension well below 80Hz...the R20 mains I'm running? What about the CSi center and R15 surrounds, though?

comfortablycurt

Mike LoManaco wrote: »

Thanks, As Always, Curt...

But which speakers are you referring to that have an extension well below 80Hz...the R20 mains I'm running? What about the CSi center and R15 surrounds, though?

The CSi30 has a rated frequency response of 52hz-27khz, the R20 mains have a rated frequency response of 55-24khz and the R15 surrounds have a rated frequency response of 60-24khz. You'll be perfect fine running all of them with an 80 hz crossover point. Even if they didn't have a frequency response that low, you'd still be perfectly fine, it wouldn't hurt the speakers at all. The low frequencies would just be rolling off before they hit the crossover point. You won't have that problem though with them set at 80hz.

motomech

Yeah, and I would leave the PWS crossover set at 80 Hz.(full left?).
It will compound a bit with the reciever X-over giving a slightly steeper roll-off.

Mike LoManaco

Thanks so much guys...

Your help is appreciated greatly; my main concern was simply that the surrounds (R15s) needed to push less low information from them because they're so small as surrounds; is it absolutely, positively okay to keep these even small R15s on 80Hz?

dorokusai

Yes.

comfortablycurt

Mike LoManaco wrote: »

Thanks so much guys...

Your help is appreciated greatly; my main concern was simply that the surrounds (R15s) needed to push less low information from them because they're so small as surrounds; is it absolutely, positively okay to keep these even small R15s on 80Hz?

Yes. It is absolutely positively okay to keep the R15's at 80hz.

As I said before, even if they weren't able to dig that low, there is still absolutely no way that you would damage them. You could set them at full range if you wanted to, and it wouldn't damage them.

It's not as if the woofer is going to blow because it's trying to reproduce a frequency lower than it's capable of.

It would simply roll off prematurely, before the crossover point.

So, yes, it is absolutely, positively and completely safe to run the R15's, along with the rest of your speakers, at an 80hz XO point.

Mike LoManaco

comfortablycurt wrote: »

Yes. It is absolutely positively okay to keep the R15's at 80hz.

As I said before, even if they weren't able to dig that low, there is still absolutely no way that you would damage them. You could set them at full range if you wanted to, and it wouldn't damage them.

It's not as if the woofer is going to blow because it's trying to reproduce a frequency lower than it's capable of.

It would simply roll off prematurely, before the crossover point.

So, yes, it is absolutely, positively and completely safe to run the R15's, along with the rest of your speakers, at an 80hz XO point.

Well, I wasn't worried about damaging the speaker/woofer -- it was more a matter of where those smaller R15s should roll off compared to/in conjunction with the larger R20s...

comfortablycurt

The lower -3db limit of the R15's is rated at 65hz, compared to a lower -3db limit of 60hz for the R20's. The lower -3db limit on the CSi30 is rated at 55 hz.

They'll all blend fine.

Mike LoManaco

Thank you, Curt; I suppose I shall leave all of 'em on 80Hz unless someone else has suggestions for another crossover setting in the receiver for these speakers...

comfortablycurt

Take all of this advice with a grain of salt to some extent. Everyones environment is different, so there really is no universal ideal. As I said previously, 80hz is just the general rule of thumb.

You might want to experiment with the XO points a litle bit and see what sounds best,

Mike LoManaco

comfortablycurt wrote: »

Take all of this advice with a grain of salt to some extent. Everyones environment is different, so there really is no universal ideal. As I said previously, 80hz is just the general rule of thumb.

You might want to experiment with the XO points a litle bit and see what sounds best,

Thank you; your opinions are much appreciated sir.

I know the THX spec calls for 80Hz cutoffs, but I wasn't POSITIVE this was for "all-around" speaker specs; under my Onkyo's SPEAKER CONFIGURATION menu, I can feel safe leaving FRONT, CENTER and SURROUND speakers on "80Hz" with LPF of LFE on 120Hz?

comfortablycurt

You could...but a XO point that high has never really sounded good to me. The sub and the mains/surrounds/center are producing a lot of the same frequencies then, and it usually doesn't blend the greatest. It really tends to muddy up the lower midrange and the higher bass frequencies. It can also create phase issues with the speakers and really make it sound worse.

It also puts MUCH to emphasis on the lower midrange, and makes it rather unpleasant to listen to.

Like I said a few posts back, I've used a 120hz XO point on my sub before, and there were instances where I even heard voices coming from the sub.

Give it a try though, you might like it. I've always found a XO point that high to sound completely terrible though. The only situation where I'd see that to be necessary would be if you had small satellite speakers that aren't capable of reproducing frequencies below that. Your speakers are capable of it though.

If you're looking for more bass, I'd just turn the subs level on the AVR up some, rather than raising the XO point.

Mike LoManaco

comfortablycurt wrote: »

You could...but a XO point that high has never really sounded good to me. The sub and the mains/surrounds/center are producing a lot of the same frequencies then, and it usually doesn't blend the greatest. It really tends to muddy up the lower midrange and the higher bass frequencies. It can also create phase issues with the speakers and really make it sound worse.

It also puts MUCH to emphasis on the lower midrange, and makes it rather unpleasant to listen to.

Like I said a few posts back, I've used a 120hz XO point on my sub before, and there were instances where I even heard voices coming from the sub.

Give it a try though, you might like it. I've always found a XO point that high to sound completely terrible though. The only situation where I'd see that to be necessary would be if you had small satellite speakers that aren't capable of reproducing frequencies below that. Your speakers are capable of it though.

If you're looking for more bass, I'd just turn the subs level on the AVR up some, rather than raising the XO point.

Curt,

That "LPF" filter feature I was talking about on the Onkyo is the LOW PASS FILTER for LFE, which filters out unwanted hum and such; I was told to leave this on Onkyo's default of 120Hz so all the bass information comes through with "no loss"...