live sound - subs on auxes?

[locutus]

I generally agree with Ben, Paul, and Jim. It does depend on the situation, but more control is almost always a good thing. I don't see any problem with having a well calibrated system at unity and working from there, even with variable gains on a separate sub mix.

I still don't think I have ever found a perfect solution that I really like for how to route them. One thing I really do not like about the aux route is not having a "one throat to choke" solution. I can't pull back the entire system, or kill it, with just two or three convenient faders. The aux master is always someplace else. Take that aux mix and route it back to the Mono Master or something. The matrix solution usually has a similar problem. Enter the digital console, I guess.

Nathan

[fifthcircle]

A couple more comments...

90% of the time, I'm using a full range set of mains. You have a sub of sorts as a part of the big system. I'll usually set my aux for subs to provide the extra low punch that is needed.

EQ and processing is a necessary evil, but that being said, I try to run as clean as possible. You'll always have a tradeoff with processing a signal. Sometimes the benefits outweigh the costs. I use HPF (sometimes extreme) on many of my stages, and all of the other EQ and comp tricks. That being said, if I can avoid having to process something when an easy alternative is available, I *always* take that route. In the end, the mixes are bigger and more open. The result- a happy client.

Because of the way that most crossovers work, as somebody else mentioned, there is regularly stuff in the subs that you don't want there. To put it on an aux lets you control exactly what is there. It also allows for subtle "tricks" when needed. It could be adding the low end of an instrument to fatten up the sound (pianos, keyboards, tenor instruments such as trombones, tenor and bari saxes, male vocals, etc...). These are tricks that I would never pull out on a regular basis, but sometimes you just need that extra help. Let the acoustics of a situation work for you rather than processing.

--Ben

[fifthcircle]

Oh... And Nathan your comments of "one throad to choke"

Do you use VCAs or set up mute groups? I try to do this on just about all big consoles. Most analog boards have the master section right in the middle and everything is easy to get to. On digital boards, it is a bit harder, but usually fine once you set it up. The big problems get to the lower-end consoles that either don't have the functionality or it is burried in a menu. A perfect example that comes to mind is the Yamaha LS-9. No VCA and the mute group is deep on a menu that you can only get to with several key hits.

--Ben

[Darm]

I am sorry for a dumb question I might ask.
Is it ok to use a Y cable to split the signal from the mono output of the crossover to both amps that are driving subs?
In the club that I do sound pretty often they have only on xover, and so I was going to do everything in mono, feeding subs from an aux bus

[bishopthomas]

As long as you can process each processor channel separately, go for the Y!

[bishopthomas]

Originally Posted by fifthcircle

... Yamaha LS-9 ... and the mute group is deep on a menu that you can only get to with several key hits.

That's what the user defined keys are for. But I agree with you, the LS9 is not a quick console to get around on. I have a friend who insists on using it for monitor duties and I think that is by far the worst use for that console.

[fifthcircle]

We're getting to another subject here, but there aren't enough user defined keys to get to all of the features that one would need to get to on that console. I've used it as a monitor board (a client has one) and I really dislike it- so unbelievably slow. Has many of the cool features from the M7CL, but you can't get to them easily.

--Ben

[locutus]

I am thinking mostly about larger format analog desks. Even with VCAs, it still seems to be unwieldy.

Now what I think would be really practical is to turn the master faders into VCAs that control the matrix sends. The former main outs could just be part of the matrix.

Imagine you have your matrix set up to run all your LCR mains, subs, delays, downfills, frontfills, etc. and you can control the whole mess from just one (or two) fader(s). With digital magic you could even DCA control one or more Aux feeds, giving another whole dimension.

[fifthcircle]

Interesting idea if implemented right...

However, I usually set up a "master" VCA in my mixes. I use it to control the entire rig with ease when things get a bit hot. Not controlling output, but rather input side...

--Ben

[audiothings]

Originally Posted by bishopthomas

That's what the user defined keys are for. But I agree with you, the LS9 is not a quick console to get around on. I have a friend who insists on using it for monitor duties and I think that is by far the worst use for that console.

sorry for the OT, but i don't think you can assign the channels to the mute groups via user defined keys on the ls9. neither can you assign HPF on/off or dynamics on/off or shelving/parametric toggle switches for the highest and lowest eq bands. i think that console has good sound and features for the price point and footprint, but it could sure do with an overhauled interface. The M7CL sounds pretty much the same to me, but is SO much faster and more intuitive.

btw, in my case the aux send to the subs passed through a speaker management processor (XTA, i think) for filtering, delays and fine tuning.

thanks for the inputs and keep 'em coming...

[valthesoundman]

As far as I'm concerned, I don't like to mix on aux send subs.
Most of the time, a well tuned (which doesn't necessarily mean flat response) system and precise filtering is the way I prefer it. I can always fine tune on FOH EQ and processors to get where I want to go.

When I do have a set up on auxes, I tend to turn all channel send to unity, and then adjust +/- depending on what I need.

That's just the way I prefer it, as I can understand others preference for subs on aux. I think it's because I try and EQ my system with my own "sound", I like a thick sounding system, with lots of low mid and a rich bass in the 100Hz zone.

Smart compression and EQ is the way for me to get that thick, thumping, cardiac bass that get's the crowd going.


On a side note, in reference to the Jon Burton mix for Prodigy, I saw them in Nimes, here in France, in a roman theatre that I have mixed in before.
It made me sick. Levels where crazy, painfull in front, all the way to the top of the arena. I was wearing my -20 plugs, and it was still loud.
And bass response was just stupid. It was way way too much. And yes, I moved around the whole arena, trying to find a place to enjoy the concert, to no avail.
This venue has amazing acoustic properties, and you can mix a huge sound without having to push it. I just can't understand why these "renouned" engineers do it. Deaf? ok, please, look at the numbers. I have a meter on my Iphone, which is not very precise, I'd say +/- 3dB depending on the level and frequencies, but I was mesuring 108dB spl at the furthest quietest point I could find. Just Stoopid.

[BFSound]

Good info in this thread but i still need some help with aux fed subs.

1. do you still need a x-over with this set-up?

2. should i only send kick, bass through this? I would like to send low bass guitar and low keys through the aux subs as well as kick. And then send the mid/high bass and keys the mid and high packs.

3. Can i send everything L/R and cross it over and send the mono low sum back to an aux return and patch that to mono fader?

I only have 1 x-over which i was going to use for my mid/high stereo mix.

I dont know what to do hear i could leave keys through mains and not patch them to sub send. But i did some research and keys generally produce from 30Hz and up and bass can produce as low as 30Hz as well and also mids and highs.

Some more help would be great. Whats the best spot the seperate lows from the mids and highs as i know lows range from 30-300Hz, mids 300-3500Hz, and highs 3500-20,000Hz.

Also how would i want to set my Low-cut on the rack and Floor toms?

Thanks. again

[Jim vanBergen]

Originally Posted by locutus

I am thinking mostly about larger format analog desks. Even with VCAs, it still seems to be unwieldy.

Now what I think would be really practical is to turn the master faders into VCAs that control the matrix sends. The former main outs could just be part of the matrix.

Imagine you have your matrix set up to run all your LCR mains, subs, delays, downfills, frontfills, etc. and you can control the whole mess from just one (or two) fader(s). With digital magic you could even DCA control one or more Aux feeds, giving another whole dimension.

This is precisely what VCA 9&10 are for on the Midas Heritage series analog desks, as well as Cadac- IMO, the two top -analog- rock consoles, period.

[Jim vanBergen]

1. You need an X-O for subs if they are not self-powered and using their own, unless you are using a Crown Amp with a PIP card designed for that process. So in general, YES, unless they are self-powered and X-O'd subs.

2 & 3. You CAN send anything and everything to the subs. One of the points made on this thread about getting a well-defined and precise sub sound is limiting what gets sent to it. In my world, it depends on the music. For rock, I would not put keys in the subs, for R&B or Hip/Hop, I sure would!

What you mention in #3 sounds like it wouldbe easier to route L&R to mono (usually a single button push) and send the mono send to the X-O for the subs.

As when you do a studio mix, you don't want all the energy that an instrument CAN produce to be what you reinforce. You want to support the part that sits in a specific place in the mix. It's very important to understand this. Don't start with ANYTHING in the subs. Add elements slowly. I know some engineers who start with the kick in the subs, then add the mains, then add bass to the subs, then the mains. I like to start from the stage bleed and move forward, it's just a different way of working.

It sounds like you are not used to crossing over your system. If you're doing it on your own, make sure you know what your components are capable of. You'll be suprised that most subs are crossed over at 40Hz and 300Hz (Meyer Sound's can reproduce 400Hz!) while most "low" speakers work from 80Hz -1.2kHz, and most "highs" from 1.2-18k. Where the mids land is highly dependant on which driver the manufacturer uses and how they load it in the cabinet for proper phase alignment, because it can drift farther than a note or two!

Long discussions for another thread, perhaps?

JvB

Originally Posted by BFSound

Good info in this thread but i still need some help with aux fed subs.

1. do you still need a x-over with this set-up?

2. should i only send kick, bass through this? I would like to send low bass guitar and low keys through the aux subs as well as kick. And then send the mid/high bass and keys the mid and high packs.

3. Can i send everything L/R and cross it over and send the mono low sum back to an aux return and patch that to mono fader?

I only have 1 x-over which i was going to use for my mid/high stereo mix.

I dont know what to do hear i could leave keys through mains and not patch them to sub send. But i did some research and keys generally produce from 30Hz and up and bass can produce as low as 30Hz as well and also mids and highs.

Some more help would be great. Whats the best spot the seperate lows from the mids and highs as i know lows range from 30-300Hz, mids 300-3500Hz, and highs 3500-20,000Hz.

Also how would i want to set my Low-cut on the rack and Floor toms?

Thanks. again

[BFSound]

Originally Posted by Jim vanBergen

1. You need an X-O for subs if they are not self-powered and using their own, unless you are using a Crown Amp with a PIP card designed for that process. So in general, YES, unless they are self-powered and X-O'd subs.

2 & 3. You CAN send anything and everything to the subs. One of the points made on this thread about getting a well-defined and precise sub sound is limiting what gets sent to it. In my world, it depends on the music. For rock, I would not put keys in the subs, for R&B or Hip/Hop, I sure would!

What you mention in #3 sounds like it wouldbe easier to route L&R to mono (usually a single button push) and send the mono send to the X-O for the subs.

As when you do a studio mix, you don't want all the energy that an instrument CAN produce to be what you reinforce. You want to support the part that sits in a specific place in the mix. It's very important to understand this. Don't start with ANYTHING in the subs. Add elements slowly. I know some engineers who start with the kick in the subs, then add the mains, then add bass to the subs, then the mains. I like to start from the stage bleed and move forward, it's just a different way of working.

It sounds like you are not used to crossing over your system. If you're doing it on your own, make sure you know what your components are capable of. You'll be suprised that most subs are crossed over at 40Hz and 300Hz (Meyer Sound's can reproduce 400Hz!) while most "low" speakers work from 80Hz -1.2kHz, and most "highs" from 1.2-18k. Where the mids land is highly dependant on which driver the manufacturer uses and how they load it in the cabinet for proper phase alignment, because it can drift farther than a note or two!

Long discussions for another thread, perhaps?

JvB

Ok thats help but a few things. As for the speakers they are not self powered. They are older EV single ported 18's and ported dual 15" cabs 2 18" cabs 2 15" cabs. Both are capable of producing 40hz-2000/ 3500 Hz. They can be set up in step down do get a lower tunning freq and handle lower levels but i dont run them that way. So i do know what they are capable of.

2nd that band i work for/ mix is not really rock they are metal/ fusion/ trippy. So like slipknot but with floyed influences so keys/ samples are very important and sometime are very low and in a dropped octave so if i did not run some through subs it would not be heard through my mids and highs. So if i crossed over the sub mono send then i could isolate the low bass guitar and synths.. right.

As for the board i use a Crest CPM 32-4. 4 subs, 6 aux (2 post fader, 4 pre) and L/R and mono. Each channel has a HP/ low-cut filter.

Currently i use my DBX 2/3/4 x-over and cross lows at 70hz to my sub amps L/R, and run everything else to mid/high cabs. What frequencies should i be reproducing in my subs. was i not correct in saying that LF range is generally 30hz-300hz? Because a kick drum can produce even higher than 300 right.

Sorry i still a young engineer and learning different ways of mixing FOH. i like the idea of aux fed subs and only want to send kick, low bass and low synth and maybe 1 large F tom to my sub mix. Instead of a xover i only have the 1 can i use an EQ to boost the low frequencies below my midrange roll off on the x-over and cut the rest obviously. Or will there still be some mid-high spill from bass and keys without a x-over.

Thanks again

[Roland]

Originally Posted by BFSound

Ok thats help but a few things. As for the speakers they are not self powered. They are older EV single ported 18's and ported dual 15" cabs 2 18" cabs 2 15" cabs. Both are capable of producing 40hz-2000/ 3500 Hz. They can be set up in step down do get a lower tunning freq and handle lower levels but i dont run them that way. So i do know what they are capable of.

2nd that band i work for/ mix is not really rock they are metal/ fusion/ trippy. So like slipknot but with floyed influences so keys/ samples are very important and sometime are very low and in a dropped octave so if i did not run some through subs it would not be heard through my mids and highs. So if i crossed over the sub mono send then i could isolate the low bass guitar and synths.. right.

As for the board i use a Crest CPM 32-4. 4 subs, 6 aux (2 post fader, 4 pre) and L/R and mono. Each channel has a HP/ low-cut filter.

Currently i use my DBX 2/3/4 x-over and cross lows at 70hz to my sub amps L/R, and run everything else to mid/high cabs. What frequencies should i be reproducing in my subs. was i not correct in saying that LF range is generally 30hz-300hz? Because a kick drum can produce even higher than 300 right.

Sorry i still a young engineer and learning different ways of mixing FOH. i like the idea of aux fed subs and only want to send kick, low bass and low synth and maybe 1 large F tom to my sub mix. Instead of a xover i only have the 1 can i use an EQ to boost the low frequencies below my midrange roll off on the x-over and cut the rest obviously. Or will there still be some mid-high spill from bass and keys without a x-over.

Thanks again

For a start, if you are using aux fed subs, you don't want anything above 100hz in there, more commonly it will be around 80hz.

Secondly, yes you do need a filter network before your sub, do this incorrectly and you will muddy up your midrange, far more of a problem than any risk of mud in the sub by not using aux fed ones!

You have to decide what you want to achieve and if your gear is up to it, it's possible that the EV's and your system are of a generation where aux feeding the subs isn't going to work very well.

Regards


Roland

[AlexK]

Originally Posted by hbphotoav

Installed flown D&B T-10 line array rig with three cardioid subs flown and a pair of dual-18 B2s on the floor. We run stereo (L/R) with everything assigned through the flown array, and assign bass, kick and keys to the Mono send as well, which drives only the B2s. The flown subs are shelved off around 80 Hz; the B2s work 35-80Hz. Nice clean low end, with very little handling noise, stage thumps, etc., through the B2s. The system was tuned with the output gains normalled, allowing a bit more or less thump with the Mono fader. Works for us.

Sorry to go a little OT, but how are you finding the T-10s? I've heard them a few times and TBH thought they were far more suited for vocals.

Impeccable dispersion (frankly amazing feedback rejection) and impressive ability to 'throw' the image, but I didn't think they sounded particularly musical. I know someone who's planning on getting a d&b line array, and is planning on going Q-series over T-series despite the T-series' party trick...

[bishopthomas]

Originally Posted by audiothings

sorry for the OT, but i don't think you can assign the channels to the mute groups via user defined keys on the ls9.

You assign the mute master to a UDK. Assigning channels to mute groups is somewhere else, a simple task that doesn't require taking up a UDK.

[audiothings]

Originally Posted by bishopthomas

You assign the mute master to a UDK. Assigning channels to mute groups is somewhere else, a simple task that doesn't require taking up a UDK.

yeah... can't take 5 or 6 of the available 12 keys for the singular purpose! when i'm on that board, most of my UDKs are reserved for the mute masters... but assigning individual channels to mute groups involves navigation using the cursor keys as far as i know, and its quite a pain.

btw, wrt the OP, it seems that i am not seeing enough reasons why NOT to put the subs on auxes... given that i've gotten my personal best sound using this setup, it might just be that it is the way that best suits my mixing approach... i really don't want guitars and vocals clouding up the low frequencies, considering that most of my venues are not severely acoustically optimized...

keep 'em coming...

[BFSound]

Originally Posted by Roland

For a start, if you are using aux fed subs, you don't want anything above 100hz in there, more commonly it will be around 80hz.

Secondly, yes you do need a filter network before your sub, do this incorrectly and you will muddy up your midrange, far more of a problem than any risk of mud in the sub by not using aux fed ones!

You have to decide what you want to achieve and if your gear is up to it, it's possible that the EV's and your system are of a generation where aux feeding the subs isn't going to work very well.

Regards


Roland

Ok i can understand the first part. Right now i have my subs crossed over at 70hz maybe ill up it to around 80hz. So then would kick drum and bass freq's higher than 80 or 100 hz be fine being reproduced in my mid high cabs?

Can you tell me where its best to set my channel strip HP filters. I did some research and i know i should have my kick and bass around like 25-30Hz just to protect the speakers. I should set my guitars around 150Hz. i would probably set my keys at 30hz again to protect my subs. all my vocals are male and i know they can reach as low as 75hz so i would set those filters at 80Hz. Where i need help is setting the HP on the rest of my drums.

Thanks Guys for the help! I think i will just mix my FOH normal since i agree and Sub aux is prob not best for our older subs.

[audiothings]

Ok i can understand the first part. Right now i have my subs crossed over at 70hz maybe ill up it to around 80hz. So then would kick drum and bass freq's higher than 80 or 100 hz be fine being reproduced in my mid high cabs?

of course. just to be clear, your post fader auxillary output goes through a crossover/delay and feeds your subs. Your main outs are still feeding your tops full range, unless you have a HPF at 80 Hz or whatever, post the master outs of your console and before the inputs to the amps for the tops (which would still usually be a good idea - it would improve the efficiency and headroom of the tops).

it's possible that the EV's and your system are of a generation where aux feeding the subs isn't going to work very well.

I think i will just mix my FOH normal since i agree and Sub aux is prob not best for our older subs.

i don't think this is because of your E/V subs... its more that you need some decent loudspeaker management... a couple of dbx driveracks should sort you out, for starters... lots of ways to configure your system with them... (i know many here would consider them 'prosumer', but i'm used to seeing decent sound coming out of cheap gear).

[Darm]

Originally Posted by audiothings

of course. just to be clear, your post fader auxillary output goes through a crossover/delay and feeds your subs. Your main outs are still feeding your tops full range, unless you have a HPF at 80 Hz or whatever, post the master outs of your console and before the inputs to the amps for the tops (which would still usually be a good idea - it would improve the efficiency and headroom of the tops).

So its better to have two X overs? One for the tops and one for the subs?

[audiothings]

So its better to have two X overs? One for the tops and one for the subs?

yes that would be my opinion... under most circumstances... unless the tops by coincidence have a natural rolloff at the crossover point.

[BFSound]

Originally Posted by audiothings

of course. just to be clear, your post fader auxillary output goes through a crossover/delay and feeds your subs. Your main outs are still feeding your tops full range, unless you have a HPF at 80 Hz or whatever, post the master outs of your console and before the inputs to the amps for the tops (which would still usually be a good idea - it would improve the efficiency and headroom of the tops).




i don't think this is because of your E/V subs... its more that you need some decent loudspeaker management... a couple of dbx driveracks should sort you out, for starters... lots of ways to configure your system with them... (i know many here would consider them 'prosumer', but i'm used to seeing decent sound coming out of cheap gear).

Well on our board, CPM32-4 we have 4 pre-fader aux sends, 2 POST, 2 returns, master L/R, and MONO fader. I was thinking if i did Auz fed i would post only the kick, bass and synth to my mono fader and just use a second x/over for the sub mix. Currently we only have 1 x-over so im just running FOH 3 way stereo, subs x-over at 80Hz. tested it out last night and it sounds good i do agree aux fed subs would greatly clean it up. I can still tell there is some low mud in them.

But for our personally PA it mainly for practice every week so FOH is nice for me But The stage mix is what i focus on. I like to run 8 monitor mixes. 2 guitar, 1 for bass, 1 for keys, 1 drum, 2 for lead vocals, and 1 center fill array.

[hbphotoav]

Originally Posted by AlexK

Sorry to go a little OT, but how are you finding the T-10s? I've heard them a few times and TBH thought they were far more suited for vocals.

Impeccable dispersion (frankly amazing feedback rejection) and impressive ability to 'throw' the image, but I didn't think they sounded particularly musical. I know someone who's planning on getting a d&b line array, and is planning on going Q-series over T-series despite the T-series' party trick...

It is the flattest (i.e., most accurate) PA rig I've heard. Very little EQ in the processing (mainly dealing with the crossover points between the mains, the cardioid subs and the B2s, and the house resonant freq), and about -1.5dB at 160 on the house graphic. Otherwise, it sounds like a huge, well tuned nearfield system. The room gets really bright as we remove chairs, but that's not the PA's fault. When there is no signal, there is no sound. The speakers are dead quiet... not a bit of processing hiss. Thanks to the "impeccable dispersion" you mentioned and the fact that we have our band all on IEMs (and my impeccable gain structuring ), we have yet to hear feedback during worship sets. Zero, zilch, nada.

Pretty cool system. I wish I owned one. But I also wish my house was paid off. Take about the same amount of cash to do either.

I don't know of another system I'd like better for worship and speaking for 1,200 seats. Hard to argue with 20dB or so headroom over "normal" performance levels. It's not even thinking about breaking a sweat at 105 at FOH... and that's 10 over "normal" worship. Audible differences between 58s, OM2s, SM86s, Beta 87, BLUE dynamic and active dynamic performance mics, and the worship leader's KMS105 are not subtle. As he (the worship leader) would say (30-something that he is...)

"Me likey."