Behringer CX2310 question

[Saurav]

Hi,

My A500 amp arrived today, so I finally hooked my sub up. The CX2310 is used in "stereo 2-way + sub" mode - upper half going to the mid+tweet panel, lower half going to the woofer boxes, and now the sub out as well, which goes to a BFD and then the A500.

The mid/woofer XO works, I've been using that all these days, obviously. My question is about the summed sub output, and the XO in the middle of the unit. As far as I can tell, it's low-passing the subwoofer output, but it's not high-passing the woofers. So I essentially have a "bring the sub in under the mains" scenario. Is this how this is supposed to work? I'd thought it would high-pass the woofers as well, so I'd end up with a bandpass on the woofers with the limits set by the 2 XOs.

If this is how it works, then I guess I'll see how blending the sub goes, but part of my reason for getting a sub is so I could EQ it, and i don't really want my woofers getting the low frequencies, because that'll be exciting room modes that I won't be able to control.

There's also a 25Hz cut button on both inputs - does that cut the woofer output, or will it cut the sub as well? I guess I can answer this question by putting in a test tones CD. It doesn't sound like it's cutting the sub out, so maybe this is the closest I can come to removing the low bass from the woofers.

Anyway, I know some people here use this unit, so if anyone's tried the "stereo 2-way + sub" mode, please shed some light on this

Thanks,
Saurav

[soho54]

As you have discovered the Sub section is separate from the Low/Mid/High section. There is no band pass option.

The different sections do not interact with one another. You should be able to enable the 25hz high pass on the woofers, and still be fine on the Sub channel. I say should because I haven't tried that myself, but I am certain that is the case.

[Saurav]

Well, maybe it's time to pull out my DIY XO and rewire that to be just a high-pass at 80Hz and put that between the 2310 and the woofer amp Thanks for confirming my suspicions. My woofers have output down to about 35Hz in this room, and I doubt my sub will go much lower than that, and I can see where it needs EQ between 65Hz and 30Hz.

[ThomasW]

You might want to read this, in particular the text at the bottom of the graphic.

cx2310.gif Image not available

Most Behringer products have a reasonable FAQ section on the Behringer website, the CX2310 is no exception. The above graphic is from a folder in the FAQ section.

http://behringer-en.custhelp.com/cgi-bin/behringer_en.cfg/php/enduser/std_alp.php?p_prod_lvl1=87

[Saurav]

Hmm... I'm pretty sure that's how I have it hooked up, and I'm pretty sure that turning the middle XO dial only affected the low-pass on the sub, not the high-pass on the woofers.

I wonder if it does this if the mid-high XO is in the x10 range. Their example has the woofer doing 200Hz - 2kHz, which would be reasonable for a small 2-way I guess. I want the woofer to do 70Hz - 350Hz, so my mid/high XO buttons are in the x1 position.

I'll try the x10 tonight and see if that makes a difference. if it doesn't, then I probably have everything hooked up wrong or something.

[soho54]

The Sub xover setting has no apparent effect at all on my Low channels. When in the x1 range.

I run my Arvos on the high side with the subs on the low. I need the low/high xover to be in the 60-80hz area, so x10 is out as 440hz is the bottom.

I have tried to set the Sub out for use as a highpass on the stereo subs (with another sub connected and disconnected) and it had no effect on my stereo subs hooked up to the low channels at the frequencies I was expecting(checking).

I'll have to revisit this in x1 mode and check the sub 20hz output. Could the sub out operate at a x.01 with x1 selected and the range is dropped from 10-200hz to 1-20hz?

Something to play with when I get home. :B

[Saurav]

Could the sub out operate at a x.01 with x1 selected and the range is dropped from 10-200hz to 1-20hz?

I don't think so. I can turn that dial down to 10Hz and get no output from my sub, and turn it up to 275Hz and get a 100Hz tone to play from my sub. But if I mute the sub and listen to the woofers, nothing happens when I change that frequency.

[Dennis H]

Guys, you're confusing me with "highpass on the sub". A highpass cuts the lows. Do you mean lowpass on the sub and highpass on the woofers?

[soho54]

I can turn that dial down to 10Hz and get no output from my sub, and turn it up to 275Hz and get a 100Hz tone to play from my sub. But if I mute the sub and listen to the woofers, nothing happens when I change that frequency.

I did the same thing only I had the gain on the extra sub all the way down. I never turned it up, so I was thinking maybe I was never getting any signal then. There goes that theory.

It must only work that way in x10 mode.

Still gonna play with it tonight. :roll:

[soho54]

My bad Dennis.

I have my subs on the Low channel.

I was trying to set the Sub channel up to use it as a variable highpass for the Low channels (my subs).

[ThomasW]

Here's a TrueRTA sweep of just the 'woofer' section of my family room speakers = TC2+ in a small sealed box

[Saurav]

Guys, you're confusing me with "highpass on the sub". A highpass cuts the lows. Do you mean lowpass on the sub and highpass on the woofers?

LOL... I had it backwards in all my posts. Sorry about that. I guess I think in cuts instead of passes or something. Though that's no excuse.

[soho54]

EDIT: This is not the post you are looking for.

Saurav, you seem to be using it correctly in all your posts.

You speak of having the LP on the Sub, and a HP on the woofers is what you are looking for.

[ThomasW]

Here this one is easier to read... XO points are ~70Hz and ~175Hz. So again this is just the 'woofer' section, (not the IB sub section) of the speaker

[Saurav]

Saurav, you seem to be using it correctly in all your posts.

You speak of having the LP on the Sub, and a HP on the woofers is what you are looking for.

That's because I went back and edited all my posts

[Saurav]

Thomas, can you do me a favor... try raising the woofer/sub XO point to 175, or even 200. That should, in theory, result in no output from the woofers, and only the Maggies and the sub playing, right?

Or maybe they changed this functionality between when you bought yours and when I bought mine. Or mine's broken. Or I have it hooked up wrong. I'm pretty sure I don't have it hooked up wrong

[ThomasW]

I can make more specialized measurements after while.

It's 12 degrees outside and I need to shovel the walk.

BTW, I can't measure both the woofer and the MMG's at that high a SPL.

[soho54]

That's because I went back and edited all my posts

I'm a little backwards anyway. I read it fine.

That should, in theory, result in no output from the woofers, and only the Maggies and the sub playing, right?

Lose the "no output" part, and add "noticeably reduced output".

[Saurav]

Well, I just muted the top output and the sub output and listened to only the woofers.

[soho54]

Well, I just muted the top output and the sub output and listened to only the woofers.

And got no output?

[Saurav]

No, I got the same output from the woofers no matter what I did to the sub XO. If I muted the woofer and listened to the sub output, I could hear the sound changing with the XO frequency.

The woofer-mid XO affects the woofers (as a low-pass), but the woofer-sub XO does not high-pass the woofers. Hope I got it right this time.

[ThomasW]

Well, I just muted the top output and the sub output and listened to only the woofers.

The crossover and amps are in the basement. Everything else is in the family room. Moving between these areas to play with settings is a VERY long hike since the house is a "rambling" ranch style.

The plot you see is the IB amp off, and the MMG's unplugged.

[Saurav]

Ah, right, I forgot all the electronics was downstairs. I get annoyed just getting up from the chair to go to the corner of the room

[soho54]

Hope I got it right this time.

Yes.

I got the same thing a few months ago when I was playing around with mine. I gave up when in the manual it only talks about the sub channel as "low end re-enforcement" and gave up. I also seem to remember my manual being different from the one online in the sub section in the back.

My wife left on a business trip this morning, so I can really mess with it in a few hours. I really hope you can get the Sub channel to affect the Low channels. :T

I can go ahead and order a bigger amp. :twisted:

[soho54]

Just got through testing, and my CX3210's Sub channel xover has no effect on the Low channel xover. In x1 or x10 modes.

I tested with sine waves at 15-40hz in 5hz increments at ~85db. I set near field to the right Low speaker with the Sub on the other side of the room (a good 20ft). With the Sub you can easily hear the change while adjusting the knob. I then disconnected the positive lead from the sub driver, leaving the amp on. I heard no change from the Low channel speakers (RS 15's) while adjusting the knob. I brought out the RS meter and confirmed no change. I did the same in x1, x10, and mixed modes. The Low channel was never affected by the Sub xover settings.

I couldn't find my manual. I thought about trying it out in 3-way mode, but decided not to.

[Dennis H]

It looks like the CX3400 will do what you guys need. It's a true stereo 3-way and it has a 'low sum' button on the back panel that will mix both the L&R low outputs on the left connector. It's only a few bucks more than the CX2310 but it kinda sucks if you already have the 2310.

[Saurav]

Yeah... I bought the 2310 some months ago, and just got my sub amp yesterday. if I'd discovered this back when I bought it, I might have upgraded. I'll figure something out... maybe add another line-level filter before the woofer amp, or sell the 2310 and get a 3400.

[ThomasW]

This is the subwoofer output only, all other outputs are muted.

This is maintaining the same frequency setting for the sub XO, while using 3 different settings for the "low" XO frequency ~60Hz, ~170Hz and ~350Hz

[ThomasW]

Just to follow up on this. The 'low' out has a fixed frequency and slope at the low end of the passband.

Here's a plot of 3 different frequencies for the XO point



I've ordered one of the CX3400, and will put it in the system and run the same tests when it arrives.

[soho54]

Now the next question is how much of that roll off is natural and how much is the C3210.

I have a stereo pair of RS 15's in 13.6hz-tuned enclosures on my Low channels. I also have an unexpected roll-off with them, though nowhere near as severe as that in your graphs. Maybe -8db instead of 20db. I have been blaming my measurement gear, but now? I have a new ECM8000 on the way already, so I'll know for sure in a little while.

This could explain why I have been getting the extreme SPL's without bottoming the drivers. There really is a 20db difference from 16hz to 10hz. This would explain a lot. :roll:

Hmmm.. might need to get back with kingpin!

[Spearmint]

Thanks for posting the plots Thomas.

Wow, now I’m in a bind, I’m using stereo subs as well and that roll off is a pain.

I’m guessing the CX3400 will probably have the same roll off with its filters as well since I need stereo sub out.

Looking forward to your tests results Thomas.

Hmmm didn’t really want to use the DCX2496 in circuit with my mains, but if the CX3400 has the same roll off I may have to.

[Saurav]

I hope the 3400 works. I looked through the manual, and it has high/mid/low outputs, with the option to sum the low. Hopefully the mid output will be a true bandpass, and can have the lower end in the 60-80Hz range, so the summed low output can be sent to a sub.

Thanks for testing this, Thomas.

[Dennis H]

Remember Thomas is running dipoles. That rolloff looks like the normal dipole rolloff at the bottom end, not something caused by the crossover. I think the XO is spec'd flat down below 10 Hz.

[soho54]

These are sweeps from a small sealed TC2+ from the Maggie project, aren't they?

[Dennis H]

I guess we'll have to wait for Thomas to clear it up. A small sealed would also roll off like that if it weren't EQ'd.

[ThomasW]

That's the roll-off for the 'low' section of the 2-way, not the sub out.

These are 12" TC2+ mounted in the 18" cube Woodstyle boxes with MMG's sitting on top. Not the dipole bass section of the Arvo's.

Measurement is with a ECM8000 and done extreme nearfield = mic 1/2" from dustcap.

[soho54]

I'm just concerned. I have recommended these to other people, and something seems odd.

I find it odd that Thomas gets a 24db/octave roll off near field with a sealed sub, and I also had an extra ~8db/octave on my ported sub that was unexpected from around 35hz down. I assumed faulty measurements and never gave it a second thought until I saw big T's graphs. They just look too much like my Arvo's TC2+ roll off, and it shouldn't.

The fact that the Sub xover doesn't variably bandpass the Low channels is now known. I am just beginning to worry that there is a permanent roll off affecting the Low channels. Not a big deal if the Low channel is actually hooked to woofers, big problem if it is hooked to true subs.

[Saurav]

There's also a '25Hz cut' button on each input. I'm not sure how much it's supposed to cut by, or where it's supposed to start. But these slopes seem to start at 50Hz, and they're down 20-24dB by 25Hz, so that makes me wonder, because the numbers do kinda line up. Thomas, are you running your 2310 with the 25Hz cut engaged?

[Spearmint]

If I get a chance this weekend I might run an input into the CX2310, and measure both outputs using ETF.

[Dennis H]

I think you guys are jumping to conclusions a bit early. Somebody needs to measure the actual output of the box, not just a speaker's output. The published specs are 20 to 20K -.5dB, <5 to >60K -3dB. Behringer is usually pretty good about meeting specs.

[ThomasW]

Sorry for the confusion.... ops:

That's the nearfield of the 12" in a very small box, not the roll-off of the CX2310

If I pull the mic back into the room and dial in EQ there's acually output down to 12Hz-13Hz.



Funny how both the Arvo and this tiny sealed box have the natural acoustic roll-off I needed for the system in this room. So I never bothered to check what the crossover itself was doing.... :roll:

Sometimes it's better to be lucky rather than good... :B

So after all this time, yes Saurav you do need to use the passive XO.

[soho54]

I played around a little tonight.
There seems to be no real roll off added the the Low channel. This is a good thing for people running their uber subs on the Low channel. The Low and Sub channels do affect one another just not in any helpful ways.

Here are a couple of graphs showing a few of the irregularities. These are uncorrected numbers 2 inches from the driver, so no port output in these numbers. The sub is tuned to 13.6hz

The legend reads: channel testing (Low & Sub xovers) If the Sub channel was connected to anything or not. It made a difference. :huh:



I was ~8db short because I left the Sub channel connected to an unused amp. :E
Live and learn.
EDIT: The blue should be "Low (L65 S10) Sub" in both graphs.

[kingpin]

WooHoo.

Now I don't have to return my cx2310 and pay extra for the 3400.

Thanks Jacob and Thomas :T

Mike

[Spearmint]

Thanks Thomas & Soho for conducting the tests and posting the results.

It’s put my mind at ease thanks. :T

Can I ask why you use a sub & microphone for testing?

I’m sure TrueRTA would accept the signal on the line in of your sound card using your subwoofer cable as a source for instance.

[ThomasW]

Can I ask why you use a sub & microphone for testing?

I’m sure TrueRTA would accept the signal on the line in of your sound card using your subwoofer cable as a source for instance.

My family room system has all the electronics after the pre-amp mounted in an equipment rack in the basement. The rack is directly under the speakers. Given the long IC runs, this system has all balanced connections, and I don't have a sound card with XLR inputs...