# Controling A Sub In A 2.1 Setup



## jcmusic (Oct 26, 2012)

I am using two subs in my 2 channel system and was wondering what is the better way to control the subs? Should I use the subs xover? Or run the sub full range and use a seperate EQ just for the subs? I also have a seperate EQ for the mains...


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## JoeESP9 (Jun 29, 2009)

You may be confusing things a little. An electronic crossover (in the sub or separate) is not the same thing as an equalizer.

If you're going to use the .1 output from your receiver/amplifier to drive your sub woofers the crossover in your receiver takes precedence. That means you should set the crossover on the subs as high as it will go. The level setting (on the subs) is something you'll need to experiment with. For a start I suggest setting it at 50%.

Whether or not you choose to run an equalizer on the mains, subs, or both has nothing to do with the crossover, it's frequency or level settings.

If you are using preamp level outputs from a two channel amp/receiver into an electronic crossover, the settings on the subs should be the same as using a .1 output.


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## jcmusic (Oct 26, 2012)

Let me be a little mor clear, I am using one set of the pre outs from my pre-amp to run the subs, and the other goes to my EQ the to the amp. My quetion is I have a second EQ that I can put in front of the subs just like the mains. Would it be better to have the two EQ's controling all the filters? Or should I run the subs full range and use the subs xovers???


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## kevin360 (Oct 4, 2012)

I'm sorry, but you still haven't made very clear. I checked your system listing, but didn't see a device which qualifies as an EQ. So, when you say EQ, what is the make and model of the device to which you refer? The term EQ doesn't imply the existence of a crossover, but there are devices which handle both functions (Behringer DCX2496, for instance). Such a device could well be preferable to the crossover in the sub's plate amp, in which case you'd do as Joe suggested in the 2nd paragraph of his post (in terms of the sub's XO setting). It's all the more puzzling because you refer to using two separate 'EQ' devices, whereas a crossover would split the signal between the mains and subs (wouldn't need two of them). :scratch:


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## JoeESP9 (Jun 29, 2009)

Let me try this again: Please don't take this the wrong way, but I think you don't quite understand the difference between an equalizer and an electronic crossover.

Equalizers and crossovers are not the same thing. Nor do they have the same functions. An equalizer, any equalizer can not and does not do what an electronic crossover does and vice versa. 

A crossover splits the audio signal into two or more bands so it can be directed to and amplified by different amplifiers. 

An equalizer is nothing more than a glorified multi-band tone control. 

One can't replace the other.

I don't quite understand why you need or even want to use two equalizers. 

Use the subs crossover to restrict the amount of higher frequency signal (high pass frequency cut off) the the sub produces.

Any equalizer you place before the sub-woofer will only be effective from a maximum of ~120Hz down as that's about the maximum frequency the sub produces. That means you probably have only two sliders (~30Hz and ~60Hz) that will have any effect on the sub woofer. They will function as tone controls because that's what an equalizer does. The slider centered on ~125Hz may have a small effect on the sub woofer but nothing above that will have any effect on the sub woofer.

If your main speakers are reasonably full range the sub woofer high pass frequency should be set somewhere close to their -3dB point. For most full range speakers that will definitely be below 100Hz and probably below 60Hz. That makes using most equalizers a worthless effort. The level control on the sub woofer is more than adequate for adjusting bass level.

To Sonny and all the Mods:
The new banner that identifies the OP of a thread is a very nice touch.


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## jcmusic (Oct 26, 2012)

Ok Joe lets try this again, the EQ's I am using are Yamaha YDP 2006 parametric Eq's. my mains have their own xovers and so do the subs. Now I know what each one does. So I am using REW t measure the room and then use the EQ to adjust the curve trying to get it flat or near. Problem is the curves show a roll off from 100hz down from the mains without the subs playing. Using the subs to try and bring that curve up to level with the rest of the curve. Hope this helps
Also I have a seperate pre-amp and amp no reciever...


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## AudiocRaver (Jun 6, 2012)

Just a silly comment of appreciation here...

You guys have no idea how cool it is to see your posts going back and forth trying to resolve misunderstandings, and have it all done calmly, helpfully, positively, and respectfully. Only at HTS!

Bravo, and thanks! Carry on!:T


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## Blainetsuds (Feb 12, 2013)

I am in full agreement with AudiocRaver and would like to add this. I am very impressed with how patient and helpful the experienced shacksters are with us less experienced. These are just a few of the things that make this site awesome.:clap:


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## jcmusic (Oct 26, 2012)

Thanks everyone I think i have got it figured out!!!


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## kevin360 (Oct 4, 2012)

Edit/Delete - I removed the first part of this post when I realized that I made an error. Because of the underline beneath the moniker, I didn't see jcmusic; I saw icmusic. :duh: 

---

It would be silly (actually, a shame as it would undermine the raison d'être of the forum) to abandon civility in these discussions. Not everyone has been fiddling with this stuff for more than 40 years. Besides, being technically minded is not a requirement for loving music and/or movies, etc.


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## JoeESP9 (Jun 29, 2009)

jcmusic said:


> Ok Joe lets try this again, the EQ's I am using are Yamaha YDP 2006 parametric Eq's. my mains have their own xovers and so do the subs. Now I know what each one does. So I am using REW t measure the room and then use the EQ to adjust the curve trying to get it flat or near. Problem is the curves show a roll off from 100hz down from the mains without the subs playing. Using the subs to try and bring that curve up to level with the rest of the curve. Hope this helps
> Also I have a seperate pre-amp and amp no reciever...


I suggest:
Don't try to use the EQ's for anything but what they're designed for (equalization). Use the built in crossover(s) in the sub(s) to set and control the crossover frequency and overall sub woofer level. Adjust and set the level and crossover frequency before you use REW and the equalizers to fine tune for flat(er) response. 

I would start with a sub woofer crossover frequency set at ~100Hz and dial the subs in for best sound. I would do this without using REW and/or any equalizer. Once you have the subs level and crossover frequency in the ball park you can then go to using and adjusting an equalizer. IMO it would be better to first adjust the bass (from the cutoff frequency down) using REW and whatever equalizer you have in the line that feeds the subs. Equalizing the frequencies above the sub woofers cutoff frequency (to the mains) would be the last thing on my list.

I hope this helps. Your situation is similar to mine. The differences being that I have a two way electronic crossover (set at 85Hz) that drives a pair of bridged amps for my sub woofers. My mains are tube driven ESL's. I use a Behringer DSP1124P (with REW) as an equalizer (from 85Hz) down for my subs. My full range ESL's have no crossover and I don't equalize the signal going to them. I prefer room treatments. I resorted to the Behringer for bass equalization only after serious room treatment failed to resolve some bass problems. 

A word to the wise: If you adjust for flat response to 20KHz you may find that this results in a harsh shrill sound. I tried it many years ago and eventually went to a gentle roll off for the extreme treble. If you look at my signature you'll see that I also use separates.


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## kevin360 (Oct 4, 2012)

Hey Joe, I couldn't help wondering if he is employing equalizers to produce a de facto crossover - via burying the frequencies above/below what is being fed to the subs/mains. He referred to the crossovers in his speakers, but what speaker crossovers also perform input high-pass duties (for his mains)? What speakers does he have? There are too many unknowns to present proper advice. I hope the OP is not offended by any of this - not my intention. I'm just expressing why I'm confounded, and I am. 

Like you, I prefer not to EQ my mains. Unlike you, I am filtering what they are being fed via a Bryston 10B-Sub XO. So far, I haven't employed any EQ for the subs, but I have invested deeply in traps (and I'd like more). I hope the OP expounds a bit more on his setup. I am curious.


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## tonyvdb (Sep 5, 2007)

Just so you guys know the YDP 2006 is one of the very best parametric EQs out there. I have two of them myself one for my sub and the other on my mains. 
I agree, you don't want to use them as crossovers and my personal take is use them as little as possible. The pre pro should be the deciding factor for the crossovers on all speakers and use the EQ to simply flatten the response.


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## jcmusic (Oct 26, 2012)

tonyvdb said:


> Just so you guys know the YDP 2006 is one of the very best parametric EQs out there. I have two of them myself one for my sub and the other on my mains.
> I agree, you don't want to use them as crossovers and my personal take is use them as little as possible. The pre pro should be the deciding factor for the crossovers on all speakers and use the EQ to simply flatten the response.


Ok so tell me how you hve them connected and and what settings are you usigon your subs??


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## tonyvdb (Sep 5, 2007)

The EQs are just hooked up between the receiver (a pre pro is the same) and the sub and between the same and the amp that goes to my mains. As far as settings my setup would be different than you so that would be pointless to say. 
REW is going to tell you what you would need to do.


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## JoeESP9 (Jun 29, 2009)

kevin360 said:


> Hey Joe, I couldn't help wondering if he is employing equalizers to produce a de facto crossover - via burying the frequencies above/below what is being fed to the subs/mains. He referred to the crossovers in his speakers, but what speaker crossovers also perform input high-pass duties (for his mains)? What speakers does he have? There are too many unknowns to present proper advice. I hope the OP is not offended by any of this - not my intention. I'm just expressing why I'm confounded, and I am.
> 
> Like you, I prefer not to EQ my mains. Unlike you, I am filtering what they are being fed via a Bryston 10B-Sub XO. So far, I haven't employed any EQ for the subs, but I have invested deeply in traps (and I'd like more). I hope the OP expounds a bit more on his setup. I am curious.


Actually my mains are also filtered. They get everything from 85Hz up. I have no other crossover than an electronic crossover. My mains are full range electrostatics with no crossover and can be driven full range. 

I've got tube traps and fiberglass acoustic panels liberally placed. I resorted to equalizing the bass after serious room treatment in a dedicated room failed to smooth the bass. 

I also have gotten the impression that the OP is using equalizers in place of an electronic crossover. That's why I've mentioned their differences.


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## jcmusic (Oct 26, 2012)

Here is some more info on my system: 
I am using a 2wpc SET amp with an all tube pre-amp my speakers started life as Klipsch Khorns that have a passive xover crossed at 400hz and 6000hz. I have two SVS SB1000 subs and two Yamaha YDP 2006 Parametric EQ's. I am using a HPF in the EQ for the mains to play 80hz and above, and the subs xovers are set to play from 80hz down. This is sounding pretty good I need to figure out how to be sure the phasing on the subs is correct???


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## tonyvdb (Sep 5, 2007)

REW is the best tool for that.
http://www.roomeqwizard.com/


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## jcmusic (Oct 26, 2012)

tonyvdb said:


> REW is the best tool for that.
> http://www.roomeqwizard.com/


Yes I am sure it is, if you how to use it and what to look for!!!


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## tonyvdb (Sep 5, 2007)

Generally it's very easy to set up and use. Just ask questions and we will help. Normally a problem with phase is seen by a dip in the graph when you turn on the second sub.


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## jcmusic (Oct 26, 2012)

tonyvdb said:


> Generally it's very easy to set up and use. Just ask questions and we will help. Normally a problem with phase is seen by a dip in the graph when you turn on the second sub.


I have been using REW to measure my room I know how to set it up and use it for frequency response but, i don't know how to use it for checking the subs phasing???


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## tonyvdb (Sep 5, 2007)

Turn off one of the subs do a sweep and then turn on the second sub and do another sweep. If the graphs stay the same but give you a smooth boost across the range you want they are good. If it shows a dip you have a phase issue. Turn the phase knob on one of the subs and do the sweep until you have that smooth graph you want. It's going to take some trial and error.


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## jcmusic (Oct 26, 2012)

So a dip is what I would see if I have a phase issue? Ok and adjusting the phase on one sub would fix this? Are we talking a little turn of the phase knob or 180* turn or something else?


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## tonyvdb (Sep 5, 2007)

Yes, on one sub. turn 180 if that does not help try other spots in between. Usually the dip will be quite drastic if it's just a small 5 to 10 db dip it's most likely a placement issue.


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## jcmusic (Oct 26, 2012)

tonyvdb said:


> Yes, on one sub. turn 180 if that does not help try other spots in between. Usually the dip will be quite drastic if it's just a small 5 to 10 db dip it's most likely a placement issue.


Ok this may be a dumb question but, if I turn the phasing knob on one sub to get the desired results in the graph wouldn't that put that sub out of phase with the mains???


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## tonyvdb (Sep 5, 2007)

Being you have two subs correct? You get the best of both as you should have a smooth response even at the crossover if done right. The only area you could see a problem is at the crossover.


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## jcmusic (Oct 26, 2012)

Ok now you lost me!!! I have two subs yes so how do I adjust one of the two and stay in phase with mains???


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## tonyvdb (Sep 5, 2007)

Each of your subs has a phase adjustment, only adjust one of the subs phase. Leave the other at 0
How does the current settings look at the crossover?


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## jcmusic (Oct 26, 2012)

Ok I understand leaving one at 0 and adjusting the other one but, wouldn't that put that sub out of phase with the mains???


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## tonyvdb (Sep 5, 2007)

But your mains are crossed over at 80hz or somewhere around their correct? If your trying to run your mains full range yes the could but not nessisarally as phase is also about delay and how far away the second sub is away from them. Lots at play here.


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## jcmusic (Oct 26, 2012)

Yes I am using a HPF at 80hz for the mains and the subs are crossed at 80hz also, ok I am starting to get it now. The mains are not going to be doing much around the 80hz area so the phasing is of littl or no value correct???


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## tonyvdb (Sep 5, 2007)

Well because your still leaving one of the subs phase at 0 you should not have any issues at the crossover.
Can you post one of your graphs here?


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## jcmusic (Oct 26, 2012)

I don't have any current ones, I need to take measuements soon.


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## JoeESP9 (Jun 29, 2009)

jcmusic said:


> Here is some more info on my system:
> I am using a 2wpc SET amp with an all tube pre-amp my speakers started life as Klipsch Khorns that have a passive xover crossed at 400hz and 6000hz. I have two SVS SB1000 subs and two Yamaha YDP 2006 Parametric EQ's. I am using a HPF in the EQ for the mains to play 80hz and above, and the subs xovers are set to play from 80hz down. This is sounding pretty good I need to figure out how to be sure the phasing on the subs is correct???


Set the equalizers to flat and get the crossover frequency, phase and level adjustments dialed in first. You can use REW for this. After you get the crossover frequencies, speaker levels and phasing correct then, and only then, should you start using REW (with a calibrated microphone) to equalize for a flatter response. 

One thing at a time!

This is the order I did it.
1. Dial in and set the crossover frequency.
2. Adjust phase of sub woofers.
3. Use parametric equalizer to smooth response.
I had to do some minor tweaking back and forth between step one and step two.


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## jcmusic (Oct 26, 2012)

Ok Joe thanks for the advice...


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## corradizo (Jan 19, 2014)

I leave both subs on at 0 and do a sweep, then set them to 180 and do another sweep. Loudest sweep in db wins. You want your subs to act as a single unit and should EQ them that way. Trying to Eq and phase adjust them separately would be a real challenge I think.


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