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Upgrade the board. Get something offering variable HPF and LPF pass on all channnels. You won’t need to go thought the whole aux fed subs thing. That is like so 1990’s... mostly we used AUX fed subs because we didn't have the variable filters...
The Soundcraft ui-24r is amazing. $800 street from some on-line dealers. It is awesome! And with any of the current gen digital boards, do use an external router!
The Soundcraft ui-24r is amazing. $800 street from some on-line dealers. It is awesome! And with any of the current gen digital boards, do use an external router!
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Yep, I am sure all the big pros have stopped running aux fed subs
. (IMHO) Not going to happen.
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What about using one of the Aux sends and making a low pass filter with the eq for that output? I’m going to give that a try with my Ui16 in a few weks.
Yep, I am sure all the big pros have stopped running aux fed subs
If you ask that at Prosound.web you can near to start a religious war. Aux fed subs are a tool for sure. It is not a tool that works well in the weekend warrior context as it’s reasonably tricky to get right. Back in the analog board days it was very effective though still a pita having to ride 2 volume controls. I was an aux fed sub desciple back in the day...
These days IMo it is much easier to LPF voice mics at 120, acoustic guitar at 160, mando, banjo and others at the appropriate frequency. The UI24 offers 12, 24 and 36 dB slopes on the filters so you can really pull a ton out selectively and accomplish darned near the same thing. IMO that approach is also easier for the weekend warrior to relate to as it is essentially just another tone control... they don’t have to understand that turning up either the mains or the aux driving the subs alone, also changes the crossover point of the system...
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Yeah, it’s a pretty primitive way to do it but I guess the only alternative is external processors. You’d think they could add HPF’s to the EQ section of each master and aux with a system update.
I don't think running aux fed subs is difficult to do right, so much as it is very easy to do wrong. Definitely easier to simply run stereo and use the channel HPFs. However, IMHO, this is easy to screw up as well.
I believe running the sub on the auxes, in addition to using channel HPFs provides superior results...especially if you may be inclined to run the subs center packed where you might want to use a little delay from your digital board to get the system to integrate a bit better...of course you probably know, system tuning is a matter of art and compromise mixed in with a bunch of physics that is way beyond most of us.
I discourage using the sub aux fader as another tone control. IMHO, This is were the approach so often goes wrong! As you infer, the balance between subs and mains should be set and maintained. If more or less bass is desired, reach for the channel strip(s) and dial it in/out there. Changing the balance between subs and mains shifts the crossover frequency and introduces phase errors...assuming they were properly crossed over and phase aligned to begin with.
Generally I didn't need to ride two volume controls as the sub aux is configured post fader and the masters are set at a suitable level during sound check. In the event I needed to bump the masters, most digital boards have numerical gain indicators so all mixes can be changed by precisely the same amount. A bit less precise with analog, especially if you are dealing with rotary encoders for auxes and faders for mains.
To further complicate matters, I often ran aux fed front fills along the lip of the stage as well, and spent some effort to time align all of the speakers and delay the sound to the band's backline. This was all done crudely by ear. A top system tech would use a program such a SMAART to tune the system. I am certainly interested in learning to use this program, but hard to justify the cost for individual who no longer works in the industry.
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All good stuff. I am in between mixing board situations, but am 99% certain my next mixer move will be a wifi-tablet mixing solution.
One thing I really don't grok is how the balance between mains and sub will change the crossover frequency. I don't see how that's possible, even. If I set it at, say, 90hz, it should still crossover at 90hz regardless of volume levels. But I do see how changing the balance might change where you want to crossover.
Variable HPF on all channels should be an option with the wifi setup we'll be using the last weekend of this month.
As for my present setup, I will probably use the main mix channel for the sub, and the Alt mix channel to the Mains amp, just because of what connections are there and what cables I have onhand.
One thing I really don't grok is how the balance between mains and sub will change the crossover frequency. I don't see how that's possible, even. If I set it at, say, 90hz, it should still crossover at 90hz regardless of volume levels. But I do see how changing the balance might change where you want to crossover.
Variable HPF on all channels should be an option with the wifi setup we'll be using the last weekend of this month.
As for my present setup, I will probably use the main mix channel for the sub, and the Alt mix channel to the Mains amp, just because of what connections are there and what cables I have onhand.
Take a look at the image below. Note the green and blue traces meet at the crossover frequency k. If the level of the subwoofer is increased, the blue line will move vertically, and the intersection of the lines will shift to the right. This means the effective crossover frequency has shifted to a higher frequency.
More importantly, and hopefully I get this right. With a 24 db per octave L/R crossover you get ~360 degrees of phase shift across the crossover region. 180 degrees of the shift occurs in the HPF and 180 degree occurs in the LPF. With a properly dialed in system, the effective phase error between the High Passed and Low Passed signal is 0 at the crossover frequency and hopefully very small across the entire crossover range. Phase lags away from the crossover frequency in the HPF and leads away from the crossover frequency in the LPF. If you were to graph the slope of the phase, it would be the same for the HPF and LPF...but the drivers and cabinet tunings has some effect as well.
With a system tuning package like SMAART you can use time delay to overlay the phase response of the sub and main cabinets so they integrate effectively. However, if you shift the effective crossover by boosting the levels of the subs, you eventually inject phase errors in and around the crossover frequency that can effect dispersion and frequency response. I am sure some will argue this is insignificant, to which I disagree. IMHO, audio is messy enough without purposely injecting additional errors.
I prefer the system to start flat so I can use the channels strips as a paint brush on a blank palette. If you prefer hyped subs, a professional system tech could easily tune the system for smooth phase response across the crossover region. The point is, disturbing the balance between subs and mains has unintended consequences that should be considered. If you want to run hyped subs, do it, but I suggest not using the aux fader as a tone control for the reasons described above. Get you subs and mains dialed in and sounding great, then leave the balance alone!
Embarrassing Update:
I hauled the Beast to the festival, hundreds of miles.
Getting the stage ready took several hours, as it was a mess from previous functions, and we had a fairly complex arrangement.
Soundcheck went great. We were using the House PA, and fixed a monitor problem that plagued us in their system years earlier. I patched in the sub. He didn't know how to do an aux mix, or whatever, so we just ran the full mix into it.
I just dialed it in at a subtle level, and it sounded quite nice. The drums in particular had a nice roundness to them. The low B string, balls, etc. I was psyched.
I turned off the sub, as the show was hours later.
Forgot to turn it back on for showtime. 96 pounds. Hundreds of miles. Just pulled it back in the house a few minutes ago.
That was an excessive effort for a sound check. And it was a really good show, too. Ah well. My stage is going to sound nice this year. Especially with me dialing in the sub mix.
(and turning the amp on)
I hauled the Beast to the festival, hundreds of miles.
Getting the stage ready took several hours, as it was a mess from previous functions, and we had a fairly complex arrangement.
Soundcheck went great. We were using the House PA, and fixed a monitor problem that plagued us in their system years earlier. I patched in the sub. He didn't know how to do an aux mix, or whatever, so we just ran the full mix into it.
I just dialed it in at a subtle level, and it sounded quite nice. The drums in particular had a nice roundness to them. The low B string, balls, etc. I was psyched.
I turned off the sub, as the show was hours later.
Forgot to turn it back on for showtime. 96 pounds. Hundreds of miles. Just pulled it back in the house a few minutes ago.
That was an excessive effort for a sound check. And it was a really good show, too. Ah well. My stage is going to sound nice this year. Especially with me dialing in the sub mix.
(and turning the amp on)
What was the house PA?Embarrassing Update:
I hauled the Beast to the festival, hundreds of miles.
Getting the stage ready took several hours, as it was a mess from previous functions, and we had a fairly complex arrangement.
Soundcheck went great. We were using the House PA, and fixed a monitor problem that plagued us in their system years earlier. I patched in the sub. He didn't know how to do an aux mix, or whatever, so we just ran the full mix into it.
I just dialed it in at a subtle level, and it sounded quite nice. The drums in particular had a nice roundness to them. The low B string, balls, etc. I was psyched.
I turned off the sub, as the show was hours later.
Forgot to turn it back on for showtime. 96 pounds. Hundreds of miles. Just pulled it back in the house a few minutes ago.
That was an excessive effort for a sound check. And it was a really good show, too. Ah well. My stage is going to sound nice this year. Especially with me dialing in the sub mix.
Embarrassing Update:
I hauled the Beast to the festival, hundreds of miles.
Getting the stage ready took several hours, as it was a mess from previous functions, and we had a fairly complex arrangement.
Soundcheck went great. We were using the House PA, and fixed a monitor problem that plagued us in their system years earlier. I patched in the sub. He didn't know how to do an aux mix, or whatever, so we just ran the full mix into it.
I just dialed it in at a subtle level, and it sounded quite nice. The drums in particular had a nice roundness to them. The low B string, balls, etc. I was psyched.
I turned off the sub, as the show was hours later.
Forgot to turn it back on for showtime. 96 pounds. Hundreds of miles. Just pulled it back in the house a few minutes ago.
That was an excessive effort for a sound check. And it was a really good show, too. Ah well. My stage is going to sound nice this year. Especially with me dialing in the sub mix.
Well not totally a waste. You had a nice placebo effect
Last gig we couldn’t understand why thinks we’re out of whack until we realized my bandmate has changed the “sub” switch on the board (which activates the crossovers for the mains and monitors and sub although the sub has an internal crossover as well and it also boosts your he output to the sub) last time he used it (his PA my sub). At that point we’d already sound checked so left it that way although it’s sub-optimal
House PA consisted of a pair of powered mains , 12" + horn. I forget the brand. The monitors were a match to that with 10" boxes.
Plastic cases , not the best sound, but not bad per se.
Basswise, it was not a good sound, but at least the monitor mix was acceptable. Usually with these sorts of festivals with semi-pro sound people, you're lucky to hear yourself at all.
btw Bass guitar onstage was run through an SWR Cali Blonde. Good for monitor volumes, but farts out pretty quick.
