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Author Topic: 4 SM80's as possible mains for 1000 ppl?  (Read 1807 times)

David Hoover

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4 SM80's as possible mains for 1000 ppl?
« on: May 19, 2014, 01:36:52 pm »

I made one of our campuses in DDT 3D and I noticed when playing with different models that the SM80 is quite a capable speaker that evenly covered our room according to DDT 3D.  What would your opinion be in using two SM80's per side flown and two BC415's flown in the center.  I am looking at hard packing the SM80's with the center two stereo and the outer two mono side fills for the 180 degree room.  The subs would be flown verical stacked and at a 45deg angle if possible to get more even and wider coverage.  The speakers and sub would be flown about 28' in the air and the distance to the back of the room from there is 67'.  I am looking at achieving about 102dB with 10dB crest factor near the rear of the sanctuary.  I understand that the larger models will be better and louder - but as a cost effective option would it suffice?  I am so curious due to the small size and price. We enjoy the sound of the SM80's as well.  Again, this is just a look at a possible option.
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Tom Young

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Re: 4 SM80's as possible mains for 1000 ppl?
« Reply #1 on: May 19, 2014, 03:12:52 pm »

I am looking at hard packing the SM80's with the center two stereo and the outer two mono side fills for the 180 degree room.  The subs would be flown verical stacked and at a 45deg angle if possible to get more even and wider coverage.

Please elaborate on your plans for arraying the (4) SM80's.

Because subwoofers are omnidirectional (or darn close), seldom is it necessary to aim them as carefully as we would fullrange loudspeakers. One would not allow them to be aimed towards the stage/platform but one would not waste time & money arraying them down when flown from above or splaying them for wider coverage. It is also not uncommon for flown subwoofers to support fullrange loudspeakers suspended below....yet another reason to not tilt them. Even with the claimed "forward directivity" of the BC-415 subwoofer, I don't think you will achieve that much by splaying them.
« Last Edit: May 19, 2014, 03:22:44 pm by Tom Young »
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Tom Young
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Ivan Beaver

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Re: 4 SM80's as possible mains for 1000 ppl?
« Reply #2 on: May 19, 2014, 08:04:36 pm »


I agree for the most part with Tom.

The BC415 has around (I don't remember exactly) 10dB forward directivity around 80hz.  Down at 35Hz it is like 4dB or more.

They could be put in V formation to gain some more forward directivity and narrow the pattern in one plane-if that is needed.

It is hard to say how well the pair of SM80s would cover-without knowing more details.

You could forward the model to Chad@danleysoundlabs.com and have him take a look at it.  There is no charge for modeling or reviewing models.  We HIGHLY encourage it.

He is doing a lot of the modeling-or will pass it on to somebody to look at.

I am not doing as much modeling these days and am basically "out of pocket" till the endish of June.

One thing to consider-the "power rating" on the Sm80 is actually a bit low.

This is due to the fact that the actual impedance is a good bit higher than the rated 8 ohms.  So the voltage used to calculate the power is based on 8 ohms, so the actual power (which would result in greater output SPL) could be higher.

When you say you want 102dB is that A or C weighted?  102 A is pretty loud-especially for a church.

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David Hoover

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Re: 4 SM80's as possible mains for 1000 ppl?
« Reply #3 on: May 19, 2014, 10:38:39 pm »

I agree for the most part with Tom.

The BC415 has around (I don't remember exactly) 10dB forward directivity around 80hz.  Down at 35Hz it is like 4dB or more.

They could be put in V formation to gain some more forward directivity and narrow the pattern in one plane-if that is needed.

It is hard to say how well the pair of SM80s would cover-without knowing more details.

You could forward the model to Chad@danleysoundlabs.com and have him take a look at it.  There is no charge for modeling or reviewing models.  We HIGHLY encourage it.

He is doing a lot of the modeling-or will pass it on to somebody to look at.

I am not doing as much modeling these days and am basically "out of pocket" till the endish of June.

One thing to consider-the "power rating" on the Sm80 is actually a bit low.

This is due to the fact that the actual impedance is a good bit higher than the rated 8 ohms.  So the voltage used to calculate the power is based on 8 ohms, so the actual power (which would result in greater output SPL) could be higher.

When you say you want 102dB is that A or C weighted?  102 A is pretty loud-especially for a church.

Thanks for the info. I will get in touch when I am in the office.  We would need to be able to maintain about 102dBA maximum.  A normal service is about 90 with loudest parts at 94 slow A.  A praise night or whatnot would require a little more juice - around 96 to 98 slow A.  Everyone measures slow A, so I will need to look into the midbass requirements up there.  It is hard to predict speakers arrangements since we measure in A as our standard.  Everyone's C and A measurements will be different lol.  Take care!
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Ivan Beaver

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Re: 4 SM80's as possible mains for 1000 ppl?
« Reply #4 on: May 20, 2014, 06:36:46 am »

Thanks for the info. I will get in touch when I am in the office.  We would need to be able to maintain about 102dBA maximum.  A normal service is about 90 with loudest parts at 94 slow A.  A praise night or whatnot would require a little more juice - around 96 to 98 slow A.  Everyone measures slow A, so I will need to look into the midbass requirements up there.  It is hard to predict speakers arrangements since we measure in A as our standard.  Everyone's C and A measurements will be different lol.  Take care!
My "gut feeling" is that you will be just fine-assuming the coverage is there.

The Sm80 was intended to be a 'stand alone" cabinet-and therefore does not array as well as other Danley products that are intended to be arrayed.

They do a better job than many other products-due to the single source of each one.

If the center of the array could be placed on an aisle-it will should work well.

The woofers will couple down in the "midbass" area,  Also the BC415s can be run a bit higher in freq if needed.
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David Hoover

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Re: 4 SM80's as possible mains for 1000 ppl?
« Reply #5 on: May 22, 2014, 08:38:54 pm »

My "gut feeling" is that you will be just fine-assuming the coverage is there.

The Sm80 was intended to be a 'stand alone" cabinet-and therefore does not array as well as other Danley products that are intended to be arrayed.

They do a better job than many other products-due to the single source of each one.

If the center of the array could be placed on an aisle-it will should work well.

The woofers will couple down in the "midbass" area,  Also the BC415s can be run a bit higher in freq if needed.

Cool. Thank you! We have been doing some tests with two SM80 speakers. I reconfigured them with the XTI2002 amps and pulled up a recorded mix on the venue and mixed from scratch, but loud (full band). With the 1600W @ 8 ohms per SM80, they didn't hesitate to keep up with 6 TFA600L subs under each one.  Amazing! 96-100dBA and around 110dBC all slow measured. Thats just loud, but they didn't sound as loud as I expected. Smooth and effortless.  We then hard packed them and it takes a minute to get them lined up so the middle doesn't sound funny like you said, but its really not bad.  They sound huge hard packed with the extra midbass coupling.  I would think for a budget option (if a larger system can't happen) this is plently of output.  Better amps would have better sustained power that would help as well.  Thanks again!
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