Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Rich Orde]

Hey all,

From time to time in high volume situations I have been having a problem with the snare drum clipping the subs.  I will try to give you as much detail as possible.

We are using 8 JBL VRX918SP subs crossed over at 80Hz, and on the snare channel the EQ is mostly flat with a low cut at 120Hz.  I am using a Behringer X32 rack with iPad control.

As a test I isolated the subs and had the drummer hit his snare drum to the point where the subs peak.  While sticking my head in front of the sub during this, there is barely a thing coming out.  Mind you, the kick drum will knock you on your butt without peaking the amp.

The drummer's snare has a standard coated head without much dampening and is pretty thin sounding on its own.  It is being mic'ed with an SM57 from the top.  I have tried another 57 with the same result.

I used the snare EQ to notch out around 280Hz which definitely helped matters but still, it doesn't make a whole lot of sense that a sub crossed over at 80Hz would be having such a strong reaction to something in the 280 range, and especially something that barely comes out of the speaker.

Does anyone have an explanation why this would be happening and suggestions on how to remedy it?  I definitely like the presence of snare drum in the mix but at times it is constantly peaking the amp and that should not be happening.

Thanks

[Lee Buckalew]

Hey all,

From time to time in high volume situations I have been having a problem with the snare drum clipping the subs.  I will try to give you as much detail as possible.

We are using 8 JBL VRX918SP subs crossed over at 80Hz, and on the snare channel the EQ is mostly flat with a low cut at 120Hz.  I am using a Behringer X32 rack with iPad control.

A bit more detail would be helpful.
What is your signal path?
From the X32 you go to...?
From there to...?
Repeat

The DSP is set how on each cabinet?
For looping the audio from VRX918 to the cabinets DSP switches are set differently than if looping to the sub then to the top.

More details will help.

Lee

[Mac Kerr]

As a test I isolated the subs and had the drummer hit his snare drum to the point where the subs peak.  While sticking my head in front of the sub during this, there is barely a thing coming out.  Mind you, the kick drum will knock you on your butt without peaking the amp.

Does it do this if the snare mic is the only one turned on? Are you absolutely sure the high pass on the snare is engaged, and the crossover to the subs is really 80Hz?

Put a full range speaker on the sub amp and listen to the snare hits. Can you hear them now?

How are the subs fed?

Mac

[John L Nobile]

First thing I would try is to change the mic and channel. Maybe even a different board.
And are you using a HPF on the snare?

[Rich Orde]

Thanks for the replies.  Here is some more information:

The signal path is SM57 directly into the X32, X32 outputs directly into the speakers which are active cabinets with built in crossovers.  The subs run at 80Hz and below and the internal crossover feeds the top cabinets (VRX932LAP) at 80Hz and up.

I have isolated the snare mic and it is definitely the source of the clipping.  I can't put a full range speaker on the bass amp because the speakers are self powered.  The snare is plenty powerful coming out of the upper cabinets but it doesn't clip the top cabinets except in maximum volume situations.  The subs always clip first.

I never verified the crossover frequency of the cabinets but what you hear coming out of them sounds like about 80Hz and below.  You don't hear any of the upper bass frequencies that "muddy up" the music.  The HPF is definitely engaged on the snare.  If I adjust the low cut frequency lower then I can hear low end coming off the snare.

It could be a quirk with the X32 preamp or some strange characteristic of the VRX cabinets but at this time I don't have another mixer to test with.  Trying a different mic would be an option but it's something that would have to be purchased.  Any suggestions on a good snare drum mic?

[g'bye, Dick Rees]

I have isolated the snare mic and it is definitely the source of the clipping. 

I never verified the crossover frequency of the cabinets but what you hear coming out of them sounds like about 80Hz and below.  You don't hear any of the upper bass frequencies that "muddy up" the music.  The HPF is definitely engaged on the snare.  If I adjust the low cut frequency lower then I can hear low end coming off the snare.

Somewhere in here...

[Lee Buckalew]

Thanks for the replies.  Here is some more information:

The signal path is SM57 directly into the X32, X32 outputs directly into the speakers which are active cabinets with built in crossovers.  The subs run at 80Hz and below and the internal crossover feeds the top cabinets (VRX932LAP) at 80Hz and up.

I have isolated the snare mic and it is definitely the source of the clipping.  I can't put a full range speaker on the bass amp because the speakers are self powered.  The snare is plenty powerful coming out of the upper cabinets but it doesn't clip the top cabinets except in maximum volume situations.  The subs always clip first.

I never verified the crossover frequency of the cabinets but what you hear coming out of them sounds like about 80Hz and below.  You don't hear any of the upper bass frequencies that "muddy up" the music.  The HPF is definitely engaged on the snare.  If I adjust the low cut frequency lower then I can hear low end coming off the snare.

It could be a quirk with the X32 preamp or some strange characteristic of the VRX cabinets but at this time I don't have another mixer to test with.  Trying a different mic would be an option but it's something that would have to be purchased.  Any suggestions on a good snare drum mic?

In all of this writing you have not told us the signal path.
X32 outputs to which connector on which speaker, how does the line level then get to the next speaker, which speaker is it, then to the next, then to the next, etc., etc., etc..

Are the subs aux fed or do they take in full range and then send a band limited signal to the tops?
Is this run in stereo, dual mono, or just a dingle mono feed got everything?
Are all of the self powered subs clipping from the snare hits or just some?
If not all, which ones?

Lee

[Mac Kerr]

Thanks for the replies.  Here is some more information:

The signal path is SM57 directly into the X32, X32 outputs directly into the speakers which are active cabinets with built in crossovers.  The subs run at 80Hz and below and the internal crossover feeds the top cabinets (VRX932LAP) at 80Hz and up.

I have isolated the snare mic and it is definitely the source of the clipping.  I can't put a full range speaker on the bass amp because the speakers are self powered.  The snare is plenty powerful coming out of the upper cabinets but it doesn't clip the top cabinets except in maximum volume situations.  The subs always clip first.

I never verified the crossover frequency of the cabinets but what you hear coming out of them sounds like about 80Hz and below.  You don't hear any of the upper bass frequencies that "muddy up" the music.  The HPF is definitely engaged on the snare.  If I adjust the low cut frequency lower then I can hear low end coming off the snare.

It could be a quirk with the X32 preamp or some strange characteristic of the VRX cabinets but at this time I don't have another mixer to test with.  Trying a different mic would be an option but it's something that would have to be purchased.  Any suggestions on a good snare drum mic?

Since you don't hear the snare coming out of the sub, how do you know they're clipping? Since you are apparently hitting the sub with a full range signal, could your full range signal be clipping the input of the crossover in the subs? Unless the signal going to the sub is from an aux that only has the stuff you want in the subs the input is seeing your full range signal. I would feed the subs with an aux that does not have snare in it, and feed the full range with what you are using now.

Mac

[Rich Orde]

In all of this writing you have not told us the signal path.
X32 outputs to which connector on which speaker, how does the line level then get to the next speaker, which speaker is it, then to the next, then to the next, etc., etc., etc..

Are the subs aux fed or do they take in full range and then send a band limited signal to the tops?
Is this run in stereo, dual mono, or just a dingle mono feed got everything?
Are all of the self powered subs clipping from the snare hits or just some?
If not all, which ones?

Lee

X32 to sub 1 input, lo pass @ 80Hz
sub 1 output to sub 2 input, xover bypass, lo pass @ 80Hz
sub 2 output to sub 3 input, xover bypass, lo pass @ 80Hz
sub 3 output to sub 4 input, xover hi pass, lo pass @ 80Hz
sub 4 output to VRX932 input



So in other words, each sub receives a full range signal, but the lo pass is set at 80Hz.

System is run in stereo and all subs peak simultaneously from the snare drum hit.  The only other time the peak lights blink is when the kick drum peaks it in max volume situations.

could your full range signal be clipping the input of the crossover in the subs?

That is a good point.  It's very possible that the subs are set up that the peak light is pre-crossover.  This would mean that the peak light blinking is not necessarily an indication of amp clipping.

The guy who owns the sound system had been working on setting it up with separate low and high outputs but he never finished doing it.  I guess getting that done would solve this problem.  That would be the next step.

Thanks

[Mac Kerr]

System is run in stereo and all subs peak simultaneously from the snare drum hit.  The only other time the peak lights blink is when the kick drum peaks it in max volume situations.
That is a good point.  It's very possible that the subs are set up that the peak light is pre-crossover.  This would mean that the peak light blinking is not necessarily an indication of amp clipping.

The guy who owns the sound system had been working on setting it up with separate low and high outputs but he never finished doing it.  I guess getting that done would solve this problem.  That would be the next step.

Thanks

The bypass switch does not mean there are no electronics in line. I expect the snare is clipping those input electronics. Use one of the aux outs from the console to drive the subs, only putting those instruments in the aux mix that make sense in the subs, kick, bass, keys, and use the full range feed that you are using now to just drive the full range system. No snare in the subs, no vocals, no guitar, no cymbals.

Mac

[Lee Buckalew]

The bypass switch does not mean there are no electronics in line. I expect the snare is clipping those input electronics. Use one of the aux outs from the console to drive the subs, only putting those instruments in the aux mix that make sense in the subs, kick, bass, keys, and use the full range feed that you are using now to just drive the full range system. No snare in the subs, no vocals, no guitar, no cymbals.

Mac

As Mac has suggested you are clipping the input with full range signal prior to the DSP.  Here is a link to the manual.  Look on page 11 for the block diagram of the sub.  http://www.jblpro.com/ProductAttachments/DOC_574.pdf

Lee

[g'bye, Dick Rees]

As Mac has suggested you are clipping the input with full range signal prior to the DSP.  Here is a link to the manual.  Look on page 11 for the block diagram of the sub.  http://www.jblpro.com/ProductAttachments/DOC_574.pdf

Lee

See also "Input Panel" on p. 15 for proper input sensitivity settings.  The stock photo posted by the OP shows the input control fully clockwise (-10 dB setting) while the manual recommends starting with the control fully COUNTER-clockwise (+4 dB setting).

Hmmmmm...

PS...

It's likely that the snare drum hits are merely the "last straw" rather than the sole offender.

[Lee Buckalew]

See also "Input Panel" on p. 15 for proper input sensitivity settings.  The stock photo posted by the OP shows the input control fully clockwise (-10 dB setting) while the manual recommends starting with the control fully COUNTER-clockwise (+4 dB setting).

Hmmmmm...

PS...

It's likely that the snare drum hits are merely the "last straw" rather than the sole offender.

Yes, this is almost certainly a case of incorrect gain structure.  Given the signal path shown on the diagram the clipping indicated at the subs appears to be at the input to the sub rather than at the output of the amp.  The OP needs to go through his system and setup the gain structure properly. 
I would still, as Mac suggested, set up the subs as Aux fed so that I was only sending a few specific signals to the subs.

Lee

[Debbie Dunkley]

See also "Input Panel" on p. 15 for proper input sensitivity settings.  The stock photo posted by the OP shows the input control fully clockwise (-10 dB setting) while the manual recommends starting with the control fully COUNTER-clockwise (+4 dB setting).

Hmmmmm...

PS...

It's likely that the snare drum hits are merely the "last straw" rather than the sole offender.

I see this all the time - like on close ups of powered subs/ mids for sale on Craigslist. I am starting to think I'm one of only a few folks who at the end of the night, routinely goes to each cab and turns all the knobs counterclockwise before I switch them off........ I see it with amps too....

[Rich Orde]

See also "Input Panel" on p. 15 for proper input sensitivity settings.  The stock photo posted by the OP shows the input control fully clockwise (-10 dB setting) while the manual recommends starting with the control fully COUNTER-clockwise (+4 dB setting).

The reason we keep the gain wide open is because the kick drum loses too much low end and I don't like to boost lows on the main EQ or on the channel because it gives the kick drum a "pocky" sound.

If I also cut the gain to the highs equally I end up compensating for the loss of volume by bumping up the master slider on the mixer, which it seems would result in the same peaking of the subs, would it not?

I do agree that the best solution is to restructure the outputs so only lows are being sent to the subs.  I don't own the sound system and currently only have access to it at gigs.  I am just using it as originally set up by the guy who does own it.  He has never had this problem because he tends to bury the snare drum in the mix when he mixes the band.

[Rob Spence]

I leave my gains wide open so the worst a meddler can do is turn it down.

Why change em at the end of the night? You are just gonna put em back next time.


Sent from my iPad using Tapatalk HD

[William Schnake]

Use one of the aux outs from the console to drive the subs, only putting those instruments in the aux mix that make sense in the subs, kick, bass, keys, and use the full range feed that you are using now to just drive the full range system. No snare in the subs, no vocals, no guitar, no cymbals.

Mac

+100  This is how we have ran our systems for years.  It cleans up the low end and the high end.  We always use a Post Fader Aux to send to the sub, this way if you boost the Kick in the mix the sub is brought up in proportion to the Main L/R.

Bill

[Debbie Dunkley]

I leave my gains wide open so the worst a meddler can do is turn it down.

Why change em at the end of the night? You are just gonna put em back next time.


Sent from my iPad using Tapatalk HD

I've always turned amps down before turning off- always have and it comes naturally. To me it's the same as closing a door behind you even though you're just gonna open it next time....

[Rich Orde]

+100  This is how we have ran our systems for years.  It cleans up the low end and the high end.  We always use a Post Fader Aux to send to the sub, this way if you boost the Kick in the mix the sub is brought up in proportion to the Main L/R.

Bill

I can see sending a separate mix to the subs but for the tops, they don't have a built in crossover so the signal sent must have a high pass active on it from the mixer.  I will have to get my hands on the band's X32 during the week and toy around with it.

[g'bye, Dick Rees]

I can see sending a separate mix to the subs but for the tops, they don't have a built in crossover so the signal sent must have a high pass active on it from the mixer.  I will have to get my hands on the band's X32 during the week and toy around with it.

Video tutorial...there may be more...

http://youtu.be/rtwW1l-FECg

[ProSoundWeb Community]