Need PA help/ bass buzz through tweeter on PA

[Zooberwerx]

I suppose it depends on your subs. Personally, I find having bass, drums, guitars and vocals all coming out of your mains sounds a little muddy.

Then again, I am not really a sound guy so I am guessing you probably are right.

If you don't sonically assign the vocals and instrumentation correctly, that's whats gonna happen. I see where you're coming from, though. The low end is supposedly the resident domain of bass and kickdrum so why not take advantage? Problem is that there's a lot of harmonic content that falls outside the capability of any sub enclosure.

Riis

 

[Floyd Eye]

If you don't sonically assign the vocals and instrumentation correctly, that's whats gonna happen. I see where you're coming from, though. The low end is supposedly the resident domain of bass and kickdrum so why not take advantage? Problem is that there's a lot of harmonic content that falls outside the capability of any sub enclosure.

Riis

I understand that. The same is true of the kick drum, correct?

I have a large stage rig and rarely use house support and have never ran my bass through my PA, but I assumed that the frequencies not covered by the subs (18s) would be covered by my own rig rather than the 2 main speakers. I guess it would be far different if you were running an array or something.

Like I said, I am no sound guy by any stretch of the imagination, so I tend to agree with the guy who said not to listen to me.

 

[Zooberwerx]

I understand that. The same is true of the kick drum, correct?

I have a large stage rig and rarely use house support and have never ran my bass through my PA, but I assumed that the frequencies not covered by the subs (18s) would be covered by my own rig rather than the 2 main speakers. I guess it would be far different if you were running an array or something.

Like I said, I am no sound guy by any stretch of the imagination, so I tend to agree with the guy who said not to listen to me.

Yes, the same is true of the kickdrum. I always aim to emphasize the low-mid "thonk" and attenuate the low-end "boom". A good example is the kickdrum on the Grateful Dead's "Touch of Gray"....everybody knows the tune and fairly easy to follow the pattern.

I see where you're coming from now: "boost the low-end presence, cover the mids / higher-response via stage / backline". Honestly, I would just run the full-range signal to the board and use the channel strip EQ to roll out the stuff that's unwanted or creates a conflict with the balance of the mix....which is how the pros manipulate vocals and instrumentation.

Riis

 

[Floyd Eye]

Honestly, I would just run the full-range signal to the board and use the channel strip EQ to roll out the stuff that's unwanted or creates a conflict with the balance of the mix....which is how the pros manipulate vocals and instrumentation.

Riis

I'm sure that is the correct way. I have little to no experience mixing bass through my PA so I probably should not have commented just because I thought I knew something. lol

 

[Zooberwerx]

I'm sure that is the correct way. I have little to no experience mixing bass through my PA so I probably should not have commented just because I thought I knew something. lol

No, quite the opposite...I appreciate you bringing the subject to light. There are variations on the theme including aux fed subs with which folks have had success. I prefer to stick with a more conventional approach: bass > DI (box or amp) > mixer > xover > amps > mains & subwoofers. I cheat and throw in a dbx DriveRack and a couple of processors but that's half the fun.

Riis

 

[thumbknuckle]

What people have been describing in this thread is not what is generally meant by the term 'aux fed subs'. The setup is more involved than what you are describing.

It works like this: the fader is routed to a high pass filter and from there to the tops. In addition to that mix a post fader aux is routed to a low pass filter and from there to the subs.

If you set that send at unity on every channel the system behaves like a conventional tops/subs PA with a regular crossover. If you don't need something in the subs you can turn that aux on that channel down or off. If you want something exaggerated in the subs you can turn the aux on that channel up.

Some people swear by this. I'm not one of them, but it's not an uncommon thing.

 

[DuraMorte]

What people have been describing in this thread is not what is generally meant by the term 'aux fed subs'. The setup is more involved than what you are describing.

It works like this: the fader is routed to a high pass filter and from there to the tops. In addition to that mix a post fader aux is routed to a low pass filter and from there to the subs.

If you set that send at unity on every channel the system behaves like a conventional tops/subs PA with a regular crossover. If you don't need something in the subs you can turn that aux on that channel down or off. If you want something exaggerated in the subs you can turn the aux on that channel up.

Some people swear by this. I'm not one of them, but it's not an uncommon thing.

That explanation is a little complicated...
Just use a 2-channel crossover. One side connected to the board's mono out, the other to an aux send, post-fader if you have it. That way, everything goes to the tops, but only the stuff you want goes to the sub.
Alternatively, I've used the L and R outs, L to tops, R to sub. That allows me to send something to just the tops, or just the sub, or anywhere in between.
Clarity in the low frequencies improves dramatically (in my experience) using an aux-fed sub setup.

 

[thumbknuckle]

That explanation is a little complicated...
Just use a 2-channel crossover. One side connected to the board's mono out, the other to an aux send, post-fader if you have it. That way, everything goes to the tops, but only the stuff you want goes to the sub.
Alternatively, I've used the L and R outs, L to tops, R to sub. That allows me to send something to just the tops, or just the sub, or anywhere in between.
Clarity in the low frequencies improves dramatically (in my experience) using an aux-fed sub setup.

What people in this thread seem to be missing is that you are only using the high passed output from one side of the crossover and only using the low passed output from the other.

 

[DuraMorte]

What people in this thread seem to be missing is that you are only using the high passed output from one side of the crossover and only using the low passed output from the other.

Ahhhh... yeah, I did forget that critical bit of info. Oops.

 

[Barisaxman]

I've found that with judicious use of the high pass on individual channels (yes it's a filter and doesn't get rid of EVERYTHING, just rolls it off), which is variable on the Presonus Studiolive that I regularly mix with and being careful to actually set up/tune the PA around the crossover point in the system...the benefit of aux-feeding subs is greatly diminished. I think a lot of beginning bands/PA owners make the mistake with a traditional setup of picking a crossover point and expecting that to be then end of the necessary setup. Like all filters, the crossover isn't a pefect cutover from tops to subs, there's a slope involved where both cabinets will produce overlapping frequencies. These can sum acoustically and make that frequency range hotter to the ear. In a typical system crossed over anywhere between say 90-120, this contributes a HUGE amount of muddiness to the overall sound. If you take the time to grab a decent 31 band main EQ, you can roll off some extra db's in this range and clean up the sound significantly.

In a aux-fed situtation, this is just taken to extreme not sending any signal at all for channels which shouldn't have material below the crossover point (vocal mics, guitar mics, etc.). The filters are still going to leave program material in from those that DO go to the sub channel (eg bass guitar will have some material over the 90hz going to the sub depending on the slope used by the crossover), so you're still not completely eliminating the overlap, but it can help clean up that frequency range. A well integrated high pass on the channel will essentially do the same thing.

 

[DWBass]

If you have subs in your system, you need a crossover as I'm sure it has been mentioned.

Ooops. Looks like you have a crossover. Need to set it up correctly. You shouldn't be getting low frequencies out of your tweeters. Maybe the internal crossovers in the mains aren't working properly.