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[Bryant Chaffin]

I've been reading about this and I know there are lots of options for doing this.   Just weighing the different ways to solve the problem and trying to decide what is "best" for us.  May try more than one option eventually, but curious on opinions and what you would do if you were in our shoes?   I have gotten some good ideas and learned a lot, both directly and indirectly, from the forum and elsewhere, but wanted to ask more directly here to make sure we have as much info as possible in order to make an informed decision.

5-6 piece band (drums, bass, keys, acoustic and electric guitars (occasionally 2 electrics), and generally 2-4 vocalists, with a mobile setup PA for live music in varying venues, mostly indoor but occasionally outdoors.   

PA includes X32 Rack and SD8 with Ubiquiti router and LR access point/tablet and laptop control
JBL 828SP subs (have built in low pass with some options)
RCF Art 932a tops (in essence the "problem", as they have no built in high pass)
Generally run 1 wedge monitor and everyone else on IEMs (mix of wired and wireless)
Sennheiser e935 vocal mics, sometimes an e835 or SM58

The system has actually sounded pretty good sending full range out to everything, but we want to hear it with the mains high passed properly for obvious reasons.  So, how would you accomplish this?   Seems like we need a crossover or some way to send a high passed signal to the mains and either a low passed signal to the subs or send a full range and let the subs handle the low passing internally.

1.  One option is obviously an external analog crossover.  Any recommended that are good quality and not astronomically priced?   Some additional cost, space and weight in the rack are negatives, but some advantage of having it external and fairly locked down from what I can tell. 

2.   Another is an external processor like a Driverack PA2 or VENU360.   I know there are higher end management systems, but I would prefer to keep the cost of the solution down, and the VENU360 is probably upper end, if not slightly above, where I'd like to be.   Unfortunately, the used Lake LM26 DSP Processor in the marketplace is out at $2600...    I've read positives and negatives on having Driveracks in the chain, putting another A/D/A conversion in there, as well as their additional features (auto eq, auto feedback suppression) as well as the different models.  I'm leaning PA2 if I go this route at the moment based on recommendations from here (Thanks Steve-White and others).   Cost is a factor, too, as well as simplicity.   I like that it could be run from a phone and doesn't require a tablet, too, although not a requirement.

2.  I've seen it said many times in threads to just let the X32R handle the crossover/processing, but there are options here, too.   One would be to to set up a stereo matrix for the mains and another mono matrix for the subs and use the matrix eq's to do the high and low passing on the outs.   

3.  Another would be to use the LCR option and run the mains on the LR and the subs on the Center for a subs on aux setup.   I understand the benefit of not sending everything to the subs, but this seems the most complex and I've seen a few videos and posts about many don't go this route and why it's probably not the best for us.

4.  Is there another or better method of setting up a fairly simple crossover in the X32R that I am missing?

Still learning here, and I appreciate the time for responses.   Just trying to "tap the well".    Thanks.

[Rob Stevens]

I think a Driverack may be your best solution while a Matrix would generally work, it wont cut below 100 on your Mains so you may have a bit of cross-over happening still, with subs on aux or a Matrix you can definitly control what is fed to your subs, but you cant control the other lower frequencies that still hit your mains. You may want to use Both Subs on Aux/Matrix as well as external processing.

[Tim McCulloch]

I've been reading about this and I know there are lots of options for doing this.   Just weighing the different ways to solve the problem and trying to decide what is "best" for us.  May try more than one option eventually, but curious on opinions and what you would do if you were in our shoes?   I have gotten some good ideas and learned a lot, both directly and indirectly, from the forum and elsewhere, but wanted to ask more directly here to make sure we have as much info as possible in order to make an informed decision.

5-6 piece band (drums, bass, keys, acoustic and electric guitars (occasionally 2 electrics), and generally 2-4 vocalists, with a mobile setup PA for live music in varying venues, mostly indoor but occasionally outdoors.   

PA includes X32 Rack and SD8 with Ubiquiti router and LR access point/tablet and laptop control
JBL 828SP subs (have built in low pass with some options)
RCF Art 932a tops (in essence the "problem", as they have no built in high pass)
Generally run 1 wedge monitor and everyone else on IEMs (mix of wired and wireless)
Sennheiser e935 vocal mics, sometimes an e835 or SM58

The system has actually sounded pretty good sending full range out to everything, but we want to hear it with the mains high passed properly for obvious reasons.  So, how would you accomplish this?   Seems like we need a crossover or some way to send a high passed signal to the mains and either a low passed signal to the subs or send a full range and let the subs handle the low passing internally.

1.  One option is obviously an external analog crossover.  Any recommended that are good quality and not astronomically priced?   Some additional cost, space and weight in the rack are negatives, but some advantage of having it external and fairly locked down from what I can tell. 

2.   Another is an external processor like a Driverack PA2 or VENU360.   I know there are higher end management systems, but I would prefer to keep the cost of the solution down, and the VENU360 is probably upper end, if not slightly above, where I'd like to be.   Unfortunately, the used Lake LM26 DSP Processor in the marketplace is out at $2600...    I've read positives and negatives on having Driveracks in the chain, putting another A/D/A conversion in there, as well as their additional features (auto eq, auto feedback suppression) as well as the different models.  I'm leaning PA2 if I go this route at the moment based on recommendations from here (Thanks Steve-White and others).   Cost is a factor, too, as well as simplicity.   I like that it could be run from a phone and doesn't require a tablet, too, although not a requirement.

2.  I've seen it said many times in threads to just let the X32R handle the crossover/processing, but there are options here, too.   One would be to to set up a stereo matrix for the mains and another mono matrix for the subs and use the matrix eq's to do the high and low passing on the outs.   

3.  Another would be to use the LCR option and run the mains on the LR and the subs on the Center for a subs on aux setup.   I understand the benefit of not sending everything to the subs, but this seems the most complex and I've seen a few videos and posts about many don't go this route and why it's probably not the best for us.

4.  Is there another or better method of setting up a fairly simple crossover in the X32R that I am missing?

Still learning here, and I appreciate the time for responses.   Just trying to "tap the well".    Thanks.

My perspective as a console operating mixerperson:  I like matrices.  On the X32 I use 1-4 as left drive, right drive, sub drive, fills drive.  The matrices are sent their signals from Left bus, Right bus, Center/Mono bus, and (in most cases) L&R bus, respectively.  This lets me do several things but the ones important to you:  independent EQ, level, and time control available in the matrices.

In this case you'd high-pass the matrix 1&2 outputs for the RCFs, do nothing with Matrix 3 output (in terms of HP/LP filters), and high pass Matrix 4 depending on what speakers you're using and to cover what area(s).  Any corrective and/or voicing EQ to be done to tops or subs would be done in their respective matrix EQs.  Crude time alignment can be accomplished in the matrices, also.  Matrix 4 could also be a send to video or house feed, overflow... anywhere a controllable, compressable, EQ-able send could be useful.  Ditto for 5&6.

By doing this EQ and alignment in the matrices you've saved all your channel strip, bus masters and main L/R/M processing.

Now that all said, as a "system guy" I prefer to have a system controller that does these things outside of the console.  When acting as the BE for a Band You've Heard Of®, I won't be accepting any process that requires me to do this in my desk, proper system control and processing is required.  But you're mixing your band on your gear, so... one of the reasons I want the system stuff outside of the desk is to lower the likelihood of a IEM muso making inadvertent changes to processing, it's less confusing to operate the console without system distractions, and if I want/need more sophisticated processing than the rudiments available in the desk.

I'd be happy to talk through routing and sends if you go down that road.

[Russell Ault]

My perspective as a console operating mixerperson:  I like matrices.  On the X32 I use 1-4 as left drive, right drive, sub drive, fills drive.  The matrices are sent their signals from Left bus, Right bus, Center/Mono bus, and (in most cases) L&R bus, respectively.  This lets me do several things but the ones important to you:  independent EQ, level, and time control available in the matrices.

In this case you'd high-pass the matrix 1&2 outputs for the RCFs, do nothing with Matrix 3 output (in terms of HP/LP filters), and high pass Matrix 4 depending on what speakers you're using and to cover what area(s).  Any corrective and/or voicing EQ to be done to tops or subs would be done in their respective matrix EQs.  Crude time alignment can be accomplished in the matrices, also.  Matrix 4 could also be a send to video or house feed, overflow... anywhere a controllable, compressable, EQ-able send could be useful.  Ditto for 5&6.

By doing this EQ and alignment in the matrices you've saved all your channel strip, bus masters and main L/R/M processing.

Now that all said, as a "system guy" I prefer to have a system controller that does these things outside of the console.  When acting as the BE for a Band You've Heard Of®, I won't be accepting any process that requires me to do this in my desk, proper system control and processing is required.  But you're mixing your band on your gear, so... one of the reasons I want the system stuff outside of the desk is to lower the likelihood of a IEM muso making inadvertent changes to processing, it's less confusing to operate the console without system distractions, and if I want/need more sophisticated processing than the rudiments available in the desk.

I'd be happy to talk through routing and sends if you go down that road.

Tim just saved me a lot of typing, although I'd add three things:

• You may as well start by experimenting with the onboard options since they're literally free
• If you're not comfortable managing subs on a separate feed, with this setup you also have the option of feeding the Sub matrix from the L&R like everything else
• If the LPF on the subs can be bypassed (or raised up out of the way) I prefer to do my subwoofer crossover filter in the matrix as well, since it keeps everything in one place (but, then again, I also tune my PAs to be "equal amplitude", so subwoofer LPF precision might mean more to me than it does to you)

{...} while a Matrix would generally work, it wont cut below 100 on your Mains {...}

Where are you seeing this? At least on the current firmware (and, IIRC, going back to at least v3), all main/matrix crossover filters on the X/M32 (both HP and LP) can be set to any of the usual EQ frequencies (i.e. anywhere from 20 Hz to 20 kHz).

-Russ

[Bryant Chaffin]

Thanks for the replies thus far, and for the offer, Tim. 

Russ, as for your #3, I believe the LPF options on the subs are 60Hz , 80Hz , 100Hz , and 120Hz, in addition to an "SRX Top" option that is supposed to be optimized for use with a JBL SRX full range speaker.   
 

[Riley Casey]

A quick and cheap way to get the flavor of this is to send the subs from the mono buss and set up the output EQ on that buss as shown in the attachment. This is a fairly good approximation of the kind of setting you'd use in an external processor. This allows you to select which channels are sent to the subs (no vocals or high hat etc ) and it gives you an easy handle for the "subs as an effect" trick. 

[Rob Stevens]

Where are you seeing this? At least on the current firmware (and, IIRC, going back to at least v3), all main/matrix crossover filters on the X/M32 (both HP and LP) can be set to any of the usual EQ frequencies (i.e. anywhere from 20 Hz to 20 kHz).

-Russ

Yeah I wasnt quite seeing it all through in my head, I was sort of forgetting you would do a High pass/Low cut on your Main L/R as well...

I still think in the real world/ this scenario id prefer the Driverack type device.

[Russell Ault]

A quick and cheap way to get the flavor of this is to send the subs from the mono buss and set up the output EQ on that buss as shown in the attachment. This is a fairly good approximation of the kind of setting you'd use in an external processor. This allows you to select which channels are sent to the subs (no vocals or high hat etc ) and it gives you an easy handle for the "subs as an effect" trick.

Just out of curiosity, why are you high-passing your subs?

-Russ

[Brian Jojade]

Just out of curiosity, why are you high-passing your subs?

-Russ

Hi passing subs keeps the ultra low frequencies out of the sub that it can't reproduce anyway.

As far as which method to pick, there are arguments for each.  Personally, I just use the built in crossovers of the X32 and call it a day.  Aux fed subs using the center channel are dirt easy, and then you've got your outputs right in the mixer.

If you do aux fed subs with external crossovers, you will need something that can handle 3 inputs (if doing stereo) or use 2 crossovers.  Not impossible, but definitely a bit more cumbersome.

The advantage of an external crossover is that it does indeed separate those controls from the mixer.  It would be nice if the X32 platform had some lockout features that put certain things behind a passcode, but alas, that's not the case.

Anyway, if you do use an external crossover, that does mean more gear which means more to lug around, and one more potential failure point in the rig.

There's no right or wrong answer to your problem, so you get to pick what works best for you.

[Mike Caldwell]

As already mentioned a few times. I like system processing outside of the mixer.
Think if you need to swap in another mixer at some point, no need to worry about
a an unexpected scene glitch taking out the processing, ect.

The DBX 360 has three inputs, two can be set up as AES inputs.

[Riley Casey]

Lots of reasons to use dedicated sub processing most important of which is things like limiter settings and brand &  model specific slopes and EQ that the generic console EQ can't match That said if the OP wants to get a handle on running subs as an effect ( essentially what this set up is for ) this configuration provide that option quickly and for free. Once questions have been answered about the value of subs as a console output then it's time to drill down to the nuts and bolts of what is the best way.  Given the OPs application description and gear list I'd imagine the console output EQ option would be all he needs.

As already mentioned a few times. I like system processing outside of the mixer.
Think if you need to swap in another mixer at some point, no need to worry about
a an unexpected scene glitch taking out the processing, ect.

The DBX 360 has three inputs, two can be set up as AES inputs.

[Russell Ault]

Lots of reasons to use dedicated sub processing most important of which is things like limiter settings and brand &  model specific slopes and EQ that the generic console EQ can't match {...}

Perhaps I've spent too much time using Meyer products, but surely the 828SP (i.e. a subwoofer with a DSP amplifier so powerful that it has an LCD screen and a network jack) has all that built in, no?

Hi passing subs keeps the ultra low frequencies out of the sub that it can't reproduce anyway. {...}

Per my "too much time using Meyer" comment above, I guess I tend to ASSume that if a DSP-powered subwoofer would benefit from an HPF that the manufacturer would build that in for me.

-Russ

[Tim McCulloch]

Perhaps I've spent too much time using Meyer products, but surely the 828SP (i.e. a subwoofer with a DSP amplifier so powerful that it has an LCD screen and a network jack) has all that built in, no?

Per my "too much time using Meyer" comment above, I guess I tend to ASSume that if a DSP-powered subwoofer would benefit from an HPF that the manufacturer would build that in for me.

-Russ

Like the picture on the food package, perhaps Riley should have overlaid the words "SERVING SUGGESTION."

When I'm willing to sacrifice some ELF extension for extra LF output, I'll do what Riley shows.

[Riley Casey]

When I'm not opining on the inter webs I'm a full time Old Guy ™ so when I read JBL sub I just skip to needing amps and processing to make them work and ignore the important details. All that stuff about processing ? Fageddatoutit. Just roll with the subs as an effect from the console surface idea with the small caveat that having EQ / low pass available on the console surface would allow you to offset the crossover shift issue with running up the sub level IF you combined that with sliding the low pass filter down at the same time. Pretty fiddly thing to have to play with in real time and again given the kinds of things that make subs as effects something worth using it's not something I'd wring hands over.

https://www.youtube.com/watch?v=OjYoNL4g5Vg

Perhaps I've spent too much time using Meyer products, but surely the 828SP (i.e. a subwoofer with a DSP amplifier so powerful that it has an LCD screen and a network jack) has all that built in, no?

Per my "too much time using Meyer" comment above, I guess I tend to ASSume that if a DSP-powered subwoofer would benefit from an HPF that the manufacturer would build that in for me.

-Russ

[Russell Ault]

{...} When I'm willing to sacrifice some ELF extension for extra LF output, I'll do what Riley shows.

I think it says a lot about the kinds of shows that I tend to mix (or, perhaps, the kinds of venues that I tend to work for) that I'm more likely to find myself doing the opposite (i.e. sacrificing headroom for ELF extension by putting in a small-ish parametric boost around 30-35Hz).

-Russ

[John Schalk]

Since the OP's system is fully powered and being used for the same band on a regular basis, I can't see a reason to add an external DSP unit just to add a HP filter to the mains.  The SRX 828SP has four options for the LPF when not being used with a JBL SRX main speaker, which is the case here.  The OP can choose from 60Hz, 80Hz, 100Hz, or 120Hz on the control panel of the SRX 828SP.  FWIW, the manual kind of sort of implies that the subs are crossed over at 80Hz when used with JBL main speakers.  Annoyingly, the manual doesn't specify the filter type and slope for the crossover options.  Does anyone know if JBL uses 24dB/octave Linkwitz Riley filters on the LPF?

Once the OP chooses a LPF frequency for the subs, it's a pretty simple process to setup a matching HPF on the main eq for the L+R output in the X32.  You can even leave a small gap between the subs and tops if you want to allow for running the subs hotter than the mains.  For example, set the subs LPF at 80Hz and then add a 90Hz high pass on the main bus in the X32.  From there the "go the extra mile" step would be to use a dual channel FFT measurement app to see if the system needs any delay to align the RCF & JBL components.  The only risk to using the main eq to high-pass the RCF mains is that the eq filter needs to be added every scene/preset that the band uses. 

[David Morison]

FWIW, the manual kind of sort of implies that the subs are crossed over at 80Hz when used with JBL main speakers.  Annoyingly, the manual doesn't specify the filter type and slope for the crossover options.  Does anyone know if JBL uses 24dB/octave Linkwitz Riley filters on the LPF?

The spec sheet shows this:


Which shows the nominal crossover frequencies at more or less 6dB down from flat, so closer to LR than any other standard topology.
It also shows the "Top" setting is definitely the same as the 80Hz.
However, it looks like the Low Pass slopes are a lot steeper, around 40db/Octave, not 24.

FWIW,
David.

[Mike Caldwell]

Since the OP's system is fully powered and being used for the same band on a regular basis, I can't see a reason to add an external DSP unit just to add a HP filter to the mains.  The SRX 828SP has four options for the LPF when not being used with a JBL SRX main speaker, which is the case here.  The OP can choose from 60Hz, 80Hz, 100Hz, or 120Hz on the control panel of the SRX 828SP.  FWIW, the manual kind of sort of implies that the subs are crossed over at 80Hz when used with JBL main speakers.  Annoyingly, the manual doesn't specify the filter type and slope for the crossover options.  Does anyone know if JBL uses 24dB/octave Linkwitz Riley filters on the LPF?

Once the OP chooses a LPF frequency for the subs, it's a pretty simple process to setup a matching HPF on the main eq for the L+R output in the X32.  You can even leave a small gap between the subs and tops if you want to allow for running the subs hotter than the mains.  For example, set the subs LPF at 80Hz and then add a 90Hz high pass on the main bus in the X32.  From there the "go the extra mile" step would be to use a dual channel FFT measurement app to see if the system needs any delay to align the RCF & JBL components.  The only risk to using the main eq to high-pass the RCF mains is that the eq filter needs to be added every scene/preset that the band uses.

Yea for just a simple high pass on the top boxes doing that in the mixer would be fine. Good suggestion on under lapping the crossover.

[ProSoundWeb Community]