Loudspeakers Subwoofers and Live Musical Theater

[Silicon_Knight]

I am a volunteer tech manager (as well as sound mixer/light operator) for my church, and we produce 3-4 musical theater productions each year (one of which we take on tour). We started with borrowing equipment from various members as it was needed, but I am trying to slowly acquire equipment for the church so that we can start to have a consistent setup on which we can rely.

We have some powered PAs, a good mixer in a rolling rack, amps for monitors, wireless receivers, graphic EQs, etc. The next purchase I am weighing is whether subs would actually add anything. As I understand it, for music, splitting the very low freqs to subs can be a great way to clean up the muddiness out of the PAs and improve the intelligibility of the vocals.

My question is, for musical theater, will subs really make any significant difference? (At this time, we are not mic'ing the bass guitar (when present) or drums).

As an aside, our challenge is often that the live music is too loud. Especially when on the road with unknown venues - any bright ideas?

 

[themuzicman]

Totally depends on your show and budget constraints. I always have a L/R sub setup at a minimum if I can manage it, but that is just to give me some flexibility and have a place to route my Piano Low mic, Kick, and Bass. It cleans up some intelligibility in the mains, and gives me the LF extension I want for the instruments that need it. Also, if I have any fun SFX like thunderstorms or whatnot, they have a place to go. If you're doing a show like Hair, you'll want subs for sure. If you're doing Hello Dolly, I don't see a huge benefit from having subs when you can focus your money on other places in the sound system you will need it.

Another note on subs is to remember that a single speaker can only make one single frequency at a time, this is why adding subs adds intelligibility because in a proper frequency and phase aligned system you are taking some of the workload off of the Main PA hang. If you are adding subs, make sure that when you route to them are you sending your source material to them at the same volume you would your mains so that you are sending in phase and in amplitude. A change in amplitude will also change phase and you lose intelligibility of the system you gained by adding one in. This might be a bit above the question you are asking, but too much sub is an all too common problem these days. Subs are good, any sub is better than no sub (unless it's a super 'wubby' sub) but too much sub is worse than any sub at all - in my eyes.

 

[Silicon_Knight]

. Subs are good, any sub is better than no sub (unless it's a super 'wubby' sub) but too much sub is worse than any sub at all - in my eyes.

I love the quote!

I know that there are so many variables, and my description was not that clear. However, thank for for your response, that's essentially the "gut feeling" that I was trying to get...is it worth picking up something and experimenting. From your reply..I think the answer is: YES!

 

[damjamkato]

A change in amplitude will also change phase...

I'd just like to clarify your meaning on this. In general, an overall change in amplitude will not change the phase response. Adjusting the volume of the subwoofers will not change their individual phase response. What will change in this situation is the overall phase response of the system (mains and subs), as the level variations effect the summation of the system elements.

 

[Dionysus]

I second that depending on the musical subs may or may not be particularly useful to you. However in general I'd rather have them than not for sure. I actually often tend not to run my subs from my mains for certain types of music and musicals, preferring to run them off of an aux or such. This allows greater control over the subs, so they aren't doing anything when I don't want them to. Particularly for when I only want to route certain inputs to the sub output.
This way there is NO WAY vocals, chorus mics, guitar mics, etc will go though the subwoofers (if they end up picking up frequencies that would). Also allows me to for instance associate the subs strongly to special sound effects that I want a lot of low end in.
Im not saying you have to do it that way at all but sometimes I find it can be a useful tool. I do indeed just route from the main outputs quite often as well.

I also love the quote, "wubby sub" indeed! And I agree that too much sub is very much a BAD THING. Exactly why I like to have a large degree of control over my subs.

 

[Silicon_Knight]

I actually often tend not to run my subs from my mains for certain types of music and musicals, preferring to run them off of an aux or such. This allows greater control over the subs, so they aren't doing anything when I don't want them to. Particularly for when I only want to route certain inputs to the sub output.

Agreed. I like to use a "sub-mix" to the Sub (ok...that wasn't really intentional)...this helps control freaks like me know exactly what is going where....

This way there is NO WAY vocals, chorus mics, guitar mics, etc will go though the subwoofers

That's the other gut feeling item I was wondering about...thanks for the confirmation.

We just added a sub to the main Sanctuary system (that is currently fed from the mono main mix), and I'm constantly adding a 105-160Hz HPF to stop feedback from condenser mics on the pastors. I've pleaded with the "powers that be" to move it to a sub-mix. There has been resistance because it's more "difficult" then to just have it fed from the main mix. In any event, I think we are slowly making progress... For now, I'll look into getting a small sub for our portable system and see if it helps or hurts.

 

[Dionysus]

Personally I don't see it as any more "difficult " at all. It makes things EASIER when you are talking about having to selectively EQ the subwoofer's range out of your vocals. Now I often use the HPF on the strip for vocals regardless, not going to hurt usually.
Sounds like non audio people trying to direct how audio is run and configured. They hardly know how to run it as is so adding something or re routing further confuses them.
Regardless most inputs don't need the subwoofer anyways! So if they forget to route something to the subs than who cares?

 

[Silicon_Knight]

I think we are in violent agreement... (We have a lot of volunteers, many of whom are not very experienced and only run the mixer occasionally...) I just see it as an opportunity for us to grow and learn!

 

[Timothy A. Samuelson]

I agree with the above. It's totally dependent on the specific show. Three months ago, I did Sound of Music. Didn't use them at all. I'm currently working on Green Day's American Idiot. I'm using the subs heavily between kick, low end piano, bass, and sound effects.

 

[JD]

Short of Electric Bass and/or Drums, probably the only thing that will go through the subs are sound effects and any special audio insert tracks that have serious low end. That being said, Having subs and not really using them on a show is better than not having subs and needing to use them on a show. Subs address inter-modulation distortion by allowing for less cone motion on your regular mains. If your content does not require much cone motion, then they don't really help.