Subwoofer crossover, receiver crossover, or both?

bqdla

Hi everyone,

Initially I had Polk RM6750's attached to my Yamaha RX-V1500 through the sub-out on my yamaha.... after further research, i changed to using setup #2, with speaker level connections for the sub.... and now I am a bit confused on how to set the crossover.

Do I now use the crossover on the sub, because the fronts are connected through it, or do I continue to use the crossover on my yamaha? Or do I now use both ? Are there advantages/disadvantages to using both?

Thanks in advance for any help!

McLoki

In the Yamaha - set sub to off and front speakers to large.

Set your other speakers to small with the crossover at 150hz.

Use the crossover in the sub to cross over to your front speakers. (probably around 150hz or so)

bqdla

Thanks for the quick response, i'm gonna try that now.

McLoki

BTW - I forgot to mention - Welcome to Club Polk...

Motzart

I was wondering the same for my Yamy.

My Mains and Sats are the same size....center is rather large (CS150)
On my Velo I have the knob set to direct....on the Yamy I have the crossover at 80hz.
My speakers are all hooked to the reciever not the sub.
Sub is RCA'd from the sub out to the LFE side of the sub.

McLoki

Motzart wrote: »

I was wondering the same for my Yamy.

My Mains and Sats are the same size....center is rather large (CS150)
On my Velo I have the knob set to direct....on the Yamy I have the crossover at 80hz.
My speakers are all hooked to the reciever not the sub.
Sub is RCA'd from the sub out to the LFE side of the sub.

Sounds about right. I only suggested the rather high 150hz crossover because that is as low as the sattelights the OP has will play.

Motzart

McLoki wrote: »

Sounds about right. I only suggested the rather high 150hz crossover because that is as low as the sattelights the OP has will play.

Reason I asked is cuz I never had a reciever with a adjustable crossover setting.

Now my mains and my sats should be set to small?

What about my center?

McLoki

Yep - Set everything to small. 80 or 100hz crossover sounds about right for your system.

Motzart

Thanx for the valuable info!

gqllc007

I have the RM95's, PSW-10 and they will be wired from AVR to sub and then to L/R fronts....what should the crossover be set to? I have Onkyo 606.
THANKS!!

McLoki

In your onkyo - you will set your fronts to large and sub to off. (there will be no crossover for your front speakers) all other speakers will be set to small.

Not familiar with the RM95 speakers, but I would guess the crossover at about 100 and would test at 80 and 150 to see if that sounds better to you. (for your front speakers, you will use the crossover in your sub - for your center and rear speakers - you will use the crossover in your AVR)

Michael

pearsall001

Here's a great article that I think is dead on...http://forum.ecoustics.com/bbs/messages/34579/128214.html

There are a lot of guys who think they have full range speakers, when in reality they don't... there really aren't very many that actually are (insert very $$$$$ & very large for the one's that are). Once you incorporate a quality sub (proper integration is key) or two into your system you will be rewarded with a musical presentation that a single pair of speakers just can't reproduce. Some of the confusion comes into play when one reads Large or Small setting & they think that pertains to the physical size of the speaker. They couldn't be more wrong.

Kex

pearsall001 wrote: »

... Some of the confusion comes into play when one reads Large or Small setting & they think that pertains to the physical size of the speaker. They couldn't be more wrong.

And some more confusion comes from musical reproduction priority versus explosive special effects priority from the 0.1 LFE channel. It seems to be much harder to get the "boom" out of your music than to get the "wow!" into your movies! Some people just give up, and have a separate two channel system for music, frequently with no subwoofer; and another 5.1/7.1 system for movies, with one or more subwoofers. There is even the option of using the subwoofer for music, but leaving the speakers set as large.

P.S., I haven't read the article linked above yet, so apologies are in order if I wrote anything that seems stupid to those that have!

gqllc007

McLoki....sorry about the speaker designation...they are 4 RM8's with PSW-10 Sub and a RM8 center. Am I suppose to set the crossover of the center and surround speakers to the same crossover amount?? I actually had no idea I was suppose to set the center and surrounds....I am a newbie!

gqllc007

had to subscribe to thread:D

pearsall001

Kex wrote: »

And some more confusion comes from musical reproduction priority versus explosive special effects priority from the 0.1 LFE channel. It seems to be much harder to get the "boom" out of your music than to get the "wow!" into your movies! Some people just give up, and have a separate two channel system for music, frequently with no subwoofer; and another 5.1/7.1 system for movies, with one or more subwoofers. There is even the option of using the subwoofer for music, but leaving the speakers set as large.

P.S., I haven't read the article linked above yet, so apologies are in order if I wrote anything that seems stupid to those that have!

I hear ya! I guess a lot depends on the quality of the sub you're trying to interface. But let me tell you straight up...once you experience the musicality of a seemless sub/monitor presentation, there's no going back. It does take a little work to get it just right, but man oh man when you get it right...look out!!!!

Fongolio

On my Yamaha 6160 I have all speakers set to large, subs (two 10") onboard crossovers set to max and the Yamaha sub setting crossing over at 80 Hz. Beautiful seamless bass with huge presence on movies and just right for cd sacd and dvd-audio playback. I have a seperate two channel setup for vinyl with no subs but I do use my front speakers from the HT (front speakers on a switch).

Aldous_Huxley

yay. those are awesome. LP

gqllc007

need help again.... I have 4 RM8's as sats and a RM8 center....I am replacing the sub with a new PSW-505.....
I have the Onkyo TXSR 606 setting the sub to off and wiring into the sub then wiring the Fronts from the sub. I will put the fronts on Large and the rest of the speakers on small. Crossover should be what? For the sub should it be 120?? and what for the other speakers?? They will be set by the Onkyo and should they be 100-150??? THANKS FOR ALL THE HELP....are their OTHER sub settings??

pearsall001

Why in the world are you even considering setting your sats to large????? I gotta hear this one!

gqllc007

Because that is what POLK recommended??????? from their home theater

Small Satellite (sub/sat) Systems
If the subwoofer is hooked up to the front
left and right speaker or preamp outputs
(highly recommended), select “Large.”
If the subwoofer is hooked up to the
subwoofer output jack (not recommended),
select “Small.”

McLoki

You would set your fronts to large if you hook up the subwoofer using the "polk method". (fronts to sub to front speakers. in AVR fronts set to large, sub to off)

gqllc007

that is how I am setting it up....what about the crossover?

McLoki

I would guess at 120-150 for most of the RM series. As I said before - not really sure for that exact series though.

Kex

gqllc007 wrote: »

that is how I am setting it up....what about the crossover?

Is there any particular reason why you are using the "Polk Method" (speaker line method) rather than the more usual LFE method? Using the LFE connection is going to be much better for Home Theater IMO, since it will carry the dedicated 0.1 Low Frequency Effects channel from a surround sound receiver.

I'm not sure if there is an advantage to the "Polk Method" for music listening though.

gqllc007

Hi Kex,
Basically I am a newbie and most of the reviews and the "polk" reading material seems to suggest that this option of L/R from the receiver to the Sub and then to the front L/R speakers is the way to go. HOWEVER I am SOLELY basing that upon all the reading I have done....I am certainly open to suggestions...seems that polk is pretty adamant about wiring them this way???

kuntasensei

My guess is that the small satellites are probably optimal the Polk way because they may be using a custom rolloff in their subwoofer crossover to make up for the capabilities of the small satellites, as opposed to the typical slope that AVR digital crossovers use (which are ideal for bookshelf sized speakers, but perhaps not satellites). Just a guess though... but that'd be the only good reason I could think of to wire them that way.

Typically, I would advise against wiring that way for one good reason: Active crossovers can induce delay and (rarely) cause phase shifts, whereas digital crossovers made to mimic analog Linkwitz-Riley filters typically don't. Here's the gigantic caveat though: The success or failure using the subwoofer output instead of the Polk method depends greatly upon the subwoofer distance setting being properly adjusted, which is something that most people don't typically focus on. Sometimes the best distance setting may not be the actual physical distance, primarily because room acoustics can reverse/shift phase with the other speakers. The distance setting essentially acts like a variable phase control for you to align the subwoofer with the other channels. The only way to make sure you're getting a good phase correlation between the speakers and subwoofer, outside of an RTA, is to measure tones in the crossover range and tweak the distance setting up and down to see which gives the best result.

Another issue is subwoofer phase. Most subwoofers give a very basic 0/180 switch to reverse phase. With passive subs using external amplification, the same result can be achieved by simply swapping the positive and negative connections. With subwoofers that have variable phase controls, you have a dial that lets you carefully tweak phase so that it matches up with your other speakers. In the vast majority of rooms, 0 degrees is the best phase setting so long as the distances are set correctly. However, phase can be affected by subwoofer placement, proximity to room boundaries, etc., so it isn't a simple proposition no matter how you look at it.

To the guy with the Onkyo 606: The LPF OF LFE setting is not a subwoofer crossover control. What it is, in fact, is a filter for only the LFE channel. Since the LFE channel in digital soundtracks is brickwall filtered at 120Hz, you should set this to 120Hz so you're passing the entire LFE channel to your subwoofer. The only time you should use the THX default of 80Hz is if you're using speakers specifically designed to operate under THX conceits. You probably won't hear much of a difference no matter how you set this, since few soundtracks have much above 80Hz in the LFE channel anyway... but there are harmonics above 80Hz in a lot of soundtracks that contribute to the way you perceive the tone of bass, even when it's deep bass. Regardless, this control does NOT affect bass redirected from the other channels at all - that is what the per-channel crossover settings are for.

For the sake of clarity, there is no LFE connection on any AVR. There is a subwoofer out. LFE is a channel in the digital bitstream. Subwoofer out, on the other hand, carries the LFE channel AND any bass redirected from the other channels by the AVR. I see people use LFE and subwoofer out interchangeably, and it's quite incorrect, ultimately serving only to confuse people.

Having said all of the above, it's your system. Try it both ways, see what sounds best to you. Tweaking is part of the fun!

Kex

gqllc007 wrote: »

... I am certainly open to suggestions...seems that polk is pretty adamant about wiring them this way???

It does seem that way. Perhaps it is better suited to music reproduction ... I don't know, but for Home Theater, I would not bother with it. Even for music, I am far from convinced on the advantage when compared to a crossover managed by a receiver, so I would just use the LFE connection instead. If there is any good reason to prefer the "Polk Method", I would expect some of the other Club members here to voice an opinion accordingly.

Kex

kuntasensei wrote: »

My guess ...

Why do I enjoy reading all his posts so much?!

... Merry Christmas everyone!

gqllc007

****....you totally lost me...it was however informative for the parts I did understand!

Kez...I will let you know how it goes. I wish someone who has wired them both ways would chime in here...

spikegomez

McLoki wrote: »

In the Yamaha - set sub to off and front speakers to large.

Set your other speakers to small with the crossover at 150hz.

Use the crossover in the sub to cross over to your front speakers. (probably around 150hz or so)

Yeah i agree with that.... crossover in front speakers....



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