Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums > LAB Subwoofer Forum

Best option for spaced subs

(1/2) > >>

Ben Easler:
Hi all,
I have been reading what seems like countless sub articles and experimenting in the theater I work in. I see that while common, spaced subs are not really idea. However, due to there being a pit cover that sticks out on the raised stage in the theater, placing the subs to the sides of that simply is what makes sense/is possible aesthetically. They were previously hung but this was problematic in the room as well. The overall sound is definitely better with them on the ground but I do have some "power alley" issues as is to be expected. My question is what have you found to be the best compromise? The pit cover is 32' wide so the speaker boxes can be about 35' apart on center at minimum. Right now, I have only delayed the subs to the mains but am thinking I may be able to compromise by delaying one sub to the other. Thoughts or other approaches?

Tim McCulloch:

--- Quote from: Ben Easler on November 09, 2017, 07:33:48 AM ---Hi all,
I have been reading what seems like countless sub articles and experimenting in the theater I work in. I see that while common, spaced subs are not really idea. However, due to there being a pit cover that sticks out on the raised stage in the theater, placing the subs to the sides of that simply is what makes sense/is possible aesthetically. They were previously hung but this was problematic in the room as well. The overall sound is definitely better with them on the ground but I do have some "power alley" issues as is to be expected. My question is what have you found to be the best compromise? The pit cover is 32' wide so the speaker boxes can be about 35' apart on center at minimum. Right now, I have only delayed the subs to the mains but am thinking I may be able to compromise by delaying one sub to the other. Thoughts or other approaches?

--- End quote ---

Delaying one sub relative to the other side only moves "power alley" closer to the side that has been delayed but does not eliminate or moderate the effect.

Your flown subs were probably clustered together, which eliminated power alley but flown, reduced your perceived subwoofer impact.  Flow subs have more even coverage and the advantage of not being right in front of a small portion of the audience.

Why were they moved to the ground?

Ben Easler:

--- Quote from: Tim McCulloch on November 09, 2017, 10:42:37 AM ---Delaying one sub relative to the other side only moves "power alley" closer to the side that has been delayed but does not eliminate or moderate the effect.

Your flown subs were probably clustered together, which eliminated power alley but flown, reduced your perceived subwoofer impact.  Flow subs have more even coverage and the advantage of not being right in front of a small portion of the audience.

Why were they moved to the ground?

--- End quote ---

Tim,
Thanks for the response -
The subs were moved to the ground as a few consultants I had come into the space felt that they were not reaching their potential flown. Having read up on this a bit more now, perhaps flown and clustered with some better dsp control would have been a good option. However, for better or worse, they were brought down to have a larger impact and also to create separation between the mains and subs. The theater itself is a quite lively space and tended to create muddiness on the low end. The stage itself also tended to create a lot of bass build up. Perhaps the advice to go in this manner is not the best option but all seem to feel the system does sound better this way. However, I do see that there are low end issues. I know that this is not an uncommon issues. So assuming we cannot or are not flying the subs in the near future and going to try this method, how would you approach it? Would you simply run only one sub? I actually tried this and noticed that the room modes actually created similar areas of less response. In the context of music this is not nearly as big of a deal as with a simple sine wave. Taking measurements, they are not as dissimilar as I would expect either.

Lee Buckalew:

--- Quote from: Ben Easler on November 09, 2017, 03:24:30 PM ---Tim,
However, for better or worse, they were brought down to have a larger impact and also to create separation between the mains and subs. The theater itself is a quite lively space and tended to create muddiness on the low end.

--- End quote ---

By larger impact do you mean louder or do you mean a better transient response (attacks are "punchier")?
The same muddiness if you have only one sub on?



--- Quote from: Ben Easler on November 09, 2017, 03:24:30 PM ---The stage itself also tended to create a lot of bass build up.

--- End quote ---

Create bass buildup or be a part of the power alley thus having a significant amount of bass directly form the speakers?



--- Quote from: Ben Easler on November 09, 2017, 03:24:30 PM ---Perhaps the advice to go in this manner is not the best option but all seem to feel the system does sound better this way. However, I do see that there are low end issues.

--- End quote ---

Go in which manner?
Which layout provided the perceived better sound quality?


Additionally;
What are these subs (make and model)?

Do you have plenty of SPL and enough headroom if there is only one in use?

Do you have the amplification and DSP to separately power and tune the boxes?  I assume so since you indicated possibly trying to time delay 1 sub relative to the other but I wanted to ask.


Lee

John Chiara:

--- Quote from: Ben Easler on November 09, 2017, 03:24:30 PM ---Tim,
Thanks for the response -
The subs were moved to the ground as a few consultants I had come into the space felt that they were not reaching their potential flown. Having read up on this a bit more now, perhaps flown and clustered with some better dsp control would have been a good option. However, for better or worse, they were brought down to have a larger impact and also to create separation between the mains and subs. The theater itself is a quite lively space and tended to create muddiness on the low end. The stage itself also tended to create a lot of bass build up. Perhaps the advice to go in this manner is not the best option but all seem to feel the system does sound better this way. However, I do see that there are low end issues. I know that this is not an uncommon issues. So assuming we cannot or are not flying the subs in the near future and going to try this method, how would you approach it? Would you simply run only one sub? I actually tried this and noticed that the room modes actually created similar areas of less response. In the context of music this is not nearly as big of a deal as with a simple sine wave. Taking measurements, they are not as dissimilar as I would expect either.

--- End quote ---

'Lively' doesn't cause bass buildup...cubic volume does. And a variety of wall placements.

Navigation

[0] Message Index

[#] Next page