Vertical stacking is there a limit?

[JWH91]

I'm an Acoustical Physicist, so we'll talk about whats ideal here, forgetting practicalities for a bit, if that's OK. Acoustically, the taller you go, the better. Actually, the ones above your head would cover the audience better than those behind you, as your body won't be blocking the mids and highs from them. That's part of what was great about the Greatful Dead setup - its height meant the performers weren't blocking the high frequency sound. If you have to limit your stack to, say, 5 feet high, acoustically you'd be best off with the stack starting at about your ear height (so you could hear yourself) and...going up from there.

Ideally, if you stack from floor to ceiling, the reflections from the floor and ceiling make the array "look" even taller, which is this case, is a good thing - picture the ceiling and floor as mirrors, and the reflected speakers act (acousticlaly) just like what you'd see in a mirror, if that makes sense. Bass varies in a venue in 3 dimensions. If you stack from floor to ceiling, you reduce the variability to 2 dimensions. If you cover an entire wall with bass cabinets, you make a 1 dimensional situation, which would be killer in a lot of ways. Plus it'd just look awesome.

Then again, the taller you go, the more your should pay attention to how well they stack - some sort of nesting/locking brackets would be a very good idea for anything taller than you, especially since the things vibrate.

No worries there because it's all gonna be one cab, well 2 I guess. But each about 8 ft in height.

Okay I loved your answer btw. So essentially I will bring lots of rope and only play venues where I can suspend my rig from the ceiling. Actually that would be freakin awesome. 2 810s and a disco ball.

 

[BunchyMutt]

So essentially I will bring lots of rope and only play venues where I can suspend my rig from the ceiling. Actually that would be freakin awesome. 2 810s and a disco ball.

For outdoor gigs just hang them from a helicopter. I think Sweetwater has some killer holiday deals on Chinooks

 

[ThinCrappyTone]

That column would approach 10 feet tall.

...and be glorious to behold!

 

[ga_edwards]

Going slightly OT: My first band had a couple of Wemm 4x10 vertical column speaker cabs, and like fools, sold them for a song in favour or more compact system.
I wish I still had them, would make for an incredible bass rig!

 

[ga_edwards]

...and be glorious to behold!

And possibly dangerous!

 

[3orangewhips]

This thread is legit buckwild.

 

[Roland GR 88]

Whoa. Where can I go further into detail about this? I was thinking (from bottom) 15/1212/410 then Horn and tweeter, all stacked vertically, 2 separate inputs 15 and 210 for one crossover, 1212 and 210 for the other. Would that be feasible for the frequencies?

OP.....you're not going to set any sonic records with this setup. As soon as your guitarist fires up most of those said frequencies will disappear faster than Harvey Weinstein.
Good luck with this but all you'll likely achieve is a tougher load in/out, an angry soundman and a band that wishes the drummer could come if there was only room in the trailer for the kit.

 

[agedhorse]

Paging @agedhorse

What are your thoughts on two vertically-stacked 8-10 cabs? (Mechanical/gravitational issues notwithstanding....)

Might be a good way to go, especially in a large room BUT...

Yeah, there is always a "but". Going taller can become an issue as the vertical pattern shrinks (especially as the frequency increases). Sometimes, and especially in a gig where there are balconies, you really do want/need 45-60 degrees or more of vertical coverage above say 300Hz otherwise the bass can sound indistinct and unbalanced. This is assuming enough volume to cover those parts of the room with the bass rig.

Another thing that happens, is as the array length approaches multiples of the wavelength (which varies with frequency), there will be major ripples (in a straight array), and as the array length becomes long enough there will also be reflections with the floor boundary causing another set of ripples/nulls.

There is no free lunch.

 

[LordLeigh]

Might be a good way to go, especially in a large room BUT...

Yeah, there is always a "but". Going taller can become an issue as the vertical pattern shrinks (especially as the frequency increases). Sometimes, and especially in a gig where there are balconies, you really do want/need 45-60 degrees or more of vertical coverage above say 300Hz otherwise the bass can sound indistinct and unbalanced. This is assuming enough volume to cover those parts of the room with the bass rig.

Another thing that happens, is as the array length approaches multiples of the wavelength (which varies with frequency), there will be major ripples (in a straight array), and as the array length becomes long enough there will also be reflections with the floor boundary causing another set of ripples/nulls.

There is no free lunch.

So moving around the room/venue you would get hot (sweet) spots where the bass is reinforced and cold spots where there is phasing causing a reduction in the waveform?

 

[agedhorse]

So moving around the room/venue you would get hot (sweet) spots where the bass is reinforced and cold spots where there is phasing causing a reduction in the waveform?

Yes, all over the stage and room.

 

[two fingers]

Might be a good way to go, especially in a large room BUT...

Yeah, there is always a "but". Going taller can become an issue as the vertical pattern shrinks (especially as the frequency increases). Sometimes, and especially in a gig where there are balconies, you really do want/need 45-60 degrees or more of vertical coverage above say 300Hz otherwise the bass can sound indistinct and unbalanced. This is assuming enough volume to cover those parts of the room with the bass rig.

Another thing that happens, is as the array length approaches multiples of the wavelength (which varies with frequency), there will be major ripples (in a straight array), and as the array length becomes long enough there will also be reflections with the floor boundary causing another set of ripples/nulls.

There is no free lunch.

Science stuff.... I knew it was coming.

 

[chadds]

I stacked four SWR Goliath Jrs. in their horizontal position and it was too stupid high.

Stacked two end on end but gig place was small and actually sounded meh. No fullness all mids and highs.

Same place with one 4x10 was perfect. Right amount of roar and blended highs and lows. That I have to say is more the difference in the cabs than the physics philosophy of stacking. I never loved the 2x10s alone or stacked in any orientation.

As much as I respect the science I’ve been playing gigs with vocals only FOH, school cafeterias, deadened hotel banquet rooms, small restaurant/bars or huge venues with huge PAs so the benefits of stacking haven’t materialized for me.

 

[Joe Ty]

The limit would be the ceiling or supported weight limit of the lowest cab in the stack. Outdoors wind could further limit you.

 

[Jeff Scott]

...If you cover an entire wall with bass cabinets, you make a 1 dimensional situation, which would be killer in a lot of ways. Plus it'd just look awesome...

OP.....you're not going to set any sonic records with this setup. As soon as your guitarist fires up most of those said frequencies will disappear faster than Harvey Weinstein...

Oh, but the beauty in the above scenario is that there would be no room for a guitar rig. Problem solved.

...that would be freakin awesome. 2 810s and a disco ball.

 

[DavC]

your height , or height of your ladder .?

 

[MVE]

For outdoor gigs just hang them from a helicopter. I think Sweetwater has some killer holiday deals on Chinooks

Those Neve Design Chinooks sound awesome!!!

 

[Ender_rpm]

Might be a good way to go, especially in a large room BUT...

Yeah, there is always a "but". Going taller can become an issue as the vertical pattern shrinks (especially as the frequency increases). Sometimes, and especially in a gig where there are balconies, you really do want/need 45-60 degrees or more of vertical coverage above say 300Hz otherwise the bass can sound indistinct and unbalanced. This is assuming enough volume to cover those parts of the room with the bass rig.

Another thing that happens, is as the array length approaches multiples of the wavelength (which varies with frequency), there will be major ripples (in a straight array), and as the array length becomes long enough there will also be reflections with the floor boundary causing another set of ripples/nulls.

There is no free lunch.

SO is this why flown line arrays are usually in an arc shape?

 

[micguy]

as the array length becomes long enough there will also be reflections with the floor boundary causing another set of ripples/nulls.

With a decent floor (or ground outside), the floor boundary doubles the array height. Picture a mirror instead of the floor surface; the reflections you see of loudpeakers are where the sound reflections will appear to eminate from. A stack of 4 loudspeakers outdoors on a parking lot will also have 4 virtual sources "below ground" - the stack height is doubled. Even one speaker will have a virtual source due to this reflection. If you do this for all the boundaries (walls, ceiling) in a room, you'll end up with a lot of virtual sound sources, and the comb filter at any given listeing position is the result of all of them adding together - different lengths from each source to each place you might want to listen.

The most audible effects, though, are typically at low frequencies, where the nulls (places where a note drops out a lot) are big - low frequencies have long wavelengths, which makes those nulls big. If you have parallel ceiling and floor sufaces (a box shaped club), and a floor to ceiling array, with the boxes close together, the net result will approach "infinite" reflections (refelections of reflections adding height to the array ad nauseum, due to the ceiling and floor boundaries. Doing this, all those reflections will actually reduce the comb filtering effects - you'll have less nulls in the vertical plane, reducing their effects somewhat. So, if you spend enough money, there is a free.....OK, an expensive lunch.

So, a floor to ceiling stack does have benefits. Then again, the only gig I play where I bring an amp, I just have to keep up with an unamplified acoustic piano, and the ceiling is....probably 40 feet tall, so practically, I'm not going to be the one to do this experiment. We need someone with a full wallet, and a regular gig in a club with a low ceiling to do this. Remember, it's for Science. Tell your wife that, as you rent a big van to get your amp to the bar. Let us know how it goes.

 

[Nev375]

The limit would be the ceiling or supported weight limit of the lowest cab in the stack. Outdoors wind could further limit you.

This. You are going to need some guy wires and some vertical reinforcing structure at some point.

 

[Nephilymbass]

What is considered overkill for example two 410s stacked vertically sounds louder than side-by-side. Now my question is let's say we have an 810, would eight individual 10" drivers stacked vertically sound louder than your standard 810?

For those who already know me on this forum, as you can see I am sober and clearly ready to learn some theory on speaker amplification and sound waves, for the next 15 minutes at least lol

My limit is about head level. Two 810s stacked vertically is definetly out of the question for safety reasons. We jump around a lot and I’m a big guy and I don’t want an 810 falling on my head. I really question if some of the two 210 vertical stacks I see posted on talkbass would remain standing on some of the stages we play on with the give they can have when we’re jumping. Particularly the narrow non ported ones like the ampeg 210av I think it is. Some of the stages even with my 410 and 15 stack I take the casters off the 15 for added stability.