Purpose of crossover on sub? [Archive] - Audio & Video Forums

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Eric Z
02-17-2004, 05:43 AM
I'm sure this is a basic question, but still need to know the answer.

What's the purpose of the crossover on a subwoofer? Is it used to integrate the sound between the subwoofer and front speakers?

Is using the crossover beneficial?

Here's my set up-

Sony DTR315 Receiver or something like that (pretty basic- does a fine job for me)
Mirage FRX5 floor speakers
Definitive Technology PS80 subwoofer

My receiver doesn't have a sub connection, so I'm running speaker wire from the receiver to the sub and then out from the sub to the fronts.

Can I use the crossover without an connection on a receiver? If so, how? Also, is it worth it?

Thanks a bunch in advance!

I'm glad I found this place.
Eric

markw
02-17-2004, 05:58 AM
If so, you'r fine.

Obviously, the speaker INPUTS on the sub will need to be connected to the speaker outputs of your receiver.

The crossover can "filter out" the bass from the signal and channel it only to the sub, thereby relieving your main speakers from trying to reproduce the low, low bass. Thisis a good thing. It generally cleans up the overall sound since your mains strain to do the low bass anyway.

To avail yourself of this option, the speaker OUTPUTS on the sub should be connected to your main speakers.

From what you describe, it sounds like you've got this right. Just remember to set your speakers to "large" and, if you have the option, set the sub output to "no". This will channel all bass and LFE to your mains (and your sub, which will filter out the bass from your mains)

If you still want to send the full range to your mains, although I cannot fathom why, you could simply connect the sub in parallel to your main speakers, either on the same terminals or vis the "B" speaker outputs on your receiver, assuming it has them.

Eric Z
02-17-2004, 08:01 AM
Thank you, Mark! A couple follow up questions. I heard a few people (the manual for the sub, too) say to set the speakers to "large." How do I do that? Is it an option on the receiver? If so, I wonder if my receiver has that option.

It sounds like I have the crossover set up correctly- speaker wire from receiver to sub and then out to main speakers. Now I just need to make sure I have the speakers set to "large" and sub output to "no" if I have that option.

Thank you again- great help!
Eric

markw
02-17-2004, 08:22 AM
These options are for HT receivers. If that's what you have, you gotta read the manual for how to set these. Even then, not all HT receivers have all these functions.

If it's a stereo receiver, you probably don't have these options. But, the good news is that the mains are getting the full range already. So, don't worry about it. You're all set.

omikey
03-03-2004, 09:20 AM
If so, you'r fine.

Obviously, the speaker INPUTS on the sub will need to be connected to the speaker outputs of your receiver.

The crossover can "filter out" the bass from the signal and channel it only to the sub, thereby relieving your main speakers from trying to reproduce the low, low bass. Thisis a good thing. It generally cleans up the overall sound since your mains strain to do the low bass anyway.

To avail yourself of this option, the speaker OUTPUTS on the sub should be connected to your main speakers.

From what you describe, it sounds like you've got this right. Just remember to set your speakers to "large" and, if you have the option, set the sub output to "no". This will channel all bass and LFE to your mains (and your sub, which will filter out the bass from your mains)

If you still want to send the full range to your mains, although I cannot fathom why, you could simply connect the sub in parallel to your main speakers, either on the same terminals or vis the "B" speaker outputs on your receiver, assuming it has them.


WOW, Mark help me out man, sounds like you have answers to most all my questions ..... If my receiver has a SUBWOOFER out, and I send that to the SUB, then just wire my mains to the speakers out, right. Does the receiver then send only the mids and highs to the mains based on the freq crossover setting that I can adjust on the Receiver .... and sends the lows directly to the sub ?

Currenlty I have it wired like this: speaker out to mains, center, and sr, with sub out going directly to sub .... is this the best way to do this ?

Thanks, Mikey

markw
03-03-2004, 10:44 AM
WOW, Mark help me out man, sounds like you have answers to most all my questions ..... If my receiver has a SUBWOOFER out, and I send that to the SUB, then just wire my mains to the speakers out, right.

Correct.


Does the receiver then send only the mids and highs to the mains based on the freq crossover setting that I can adjust on the Receiver .... and sends the lows directly to the sub ?

Also correct.

What the LFE (sub) output does is take the lows and channel them directly to the sub. How much depends on how your speakers are set. If they are set to "small", then virtually all the bass is channeled to the sub, thereby freeing them of that task. If they are set to "large", then the mains will see ALL the bass along with the sub. This presumes that you set your receiver's settings to sub = "yes"


Currenlty I have it wired like this: speaker out to mains, center, and sr, with sub out going directly to sub .... is this the best way to do this ?
Thanks, Mikey

Yep, that's correct. That's the classic HT way to set it up. You could always use the method Eric described but, in most receivers, you would need to go into your receiver's settings and set the sub to "no" or "off". If your receiver has funky bass management, this is one way to get the sub to work for all sources, not just the digital ones.

It always pays to become somewhat familiar with your receiver's owners manual to see what features you have and don't have. You might be surprised and find some goodies you didn't even think of.

...and, you're very welcome.

omikey
03-03-2004, 11:04 AM
Mark, first THANK YOU



What the LFE (sub) output does is take the lows and channel them directly to the sub. How much depends on how your speakers are set. If they are set to "small", then virtually all the bass is channeled to the sub, thereby freeing them of that task. If they are set to "large", then the mains will see ALL the bass along with the sub. This presumes that you set your receiver's settings to sub = "yes"

So here's what I currently have (in the process of chaning, but this will educate me just the same). I have Pinnacle mains - Gold Reference Towers spec'd like this: 2 way diaduct rear venting, 1" liquid-cooled dold dome tweeter, (2) 6.5" fibercone woofers with rubber surronds, frequency response: 29-21kHz, crossover Frequency: 2.5kHz, power rated at 20-200 watts RMS per channel

Here's my question: IF I think there is to much bass in the main, then (based on your previous explaination) I could set the main speaker setting on the receiver to SMALL which would send less bass to the mains and channel more or all to the sub. Correct ?

Given the specs stated above, where should I set my frequency crossover on the receiver ?

How do I utilize the frequency crossover settings on the back of the sub ? What should it be set to ? I have the following options: 60, 80, 100, 125, 160 or 200.
Also - how do I best set the receiver and the sub settings so they are shall we say, in SYNC ........

Well, as long as I'm asking, what is the 'reverse phase' setting for on the sub ? I can hear it change, but not sure which is better




It always pays to become somewhat familiar with your receiver's owners manual to see what features you have and don't have. You might be surprised and find some goodies you didn't even think of.

I agree with you on this one, seems I need to read that thing more and more ..... I have a lot to learn.

Thanks again for your help Mark !

markw
03-03-2004, 01:39 PM
Mark, first THANK YOU





So here's what I currently have (in the process of chaning, but this will educate me just the same). I have Pinnacle mains - Gold Reference Towers spec'd like this: 2 way diaduct rear venting, 1" liquid-cooled dold dome tweeter, (2) 6.5" fibercone woofers with rubber surronds, frequency response: 29-21kHz, crossover Frequency: 2.5kHz, power rated at 20-200 watts RMS per channel

Sounds like a full range speaker to me...



Here's my question: IF I think there is to much bass in the main, then (based on your previous explaination) I could set the main speaker setting on the receiver to SMALL which would send less bass to the mains and channel more or all to the sub. Correct ?

Yes. But, the bass to the sub is constant. Setting the speakers to "large" will send the full bass to the mains as well as the sub. Setting them to "Small" will block bass going to the mains.

Now to really confuse ya... some setups allow setting all speakers individualy.



the specs stated above, where should I set my frequency crossover on the receiver ?

Expierment. Start with the lowest crossover and wotk your way up. This will minimize interaction between the sub and the mains.


How do I utilize the frequency crossover settings on the back of the sub ? What should it be set to ? I have the following options: 60, 80, 100, 125, 160 or 200.
Also - how do I best set the receiver and the sub settings so they are shall we say, in SYNC ........

Same as above. This time start at the top and work down. REmember, it ain't gonna see what the receiver ain't sending. If the receiver is set to 80 hz, the sub won't see much above that but it WILL see something. Xovers are not a brick wall. They gradually decrease the output above (or below, depending) the selected (hinge) frequency.

Actually, if it's possible, see if you can bypass the Xover in the sub and let the receiver do the math. My Velo allows this by flipping a switch and I'm pretty sure others do as well.


, as long as I'm asking, what is the 'reverse phase' setting for on the sub ? I can hear it change, but not sure which is better

Whichever sounds best. (I know it's a copout but I never could figure it out either.)

again, you're welcome. hope I helped. enjoy...

omikey
03-03-2004, 02:08 PM
Mark - Thanks once again, and let me assure you, YOU have been a great help !!

OK, so I set it up as you described, receiver set at 80 sub set to 200, sounds MUCH improved !!

I didn't see any way to disable the crossover on the sub or at the receiver.... so I think what I got now is what I'm gonna have

Now ... I just found a little switch on the back of the sub called the crossover slope, one postion is at 24db/oct the other is at 12db/oct

I've changed it, here's what I notice ... at 12db the sound from the sub is 'brighter' .... what is this really doing ?

This Guy
03-03-2004, 02:26 PM
That means the sub is producing more sound over 80 hertz because the slope isn't as steep, this may also perceive it to be louder. At 24 dB, the sub will output even less over 80 hertz becasue the slope is much steeper. Pick whatever you like most.

-Joey