Problems "Hearing" a 15" speaker

[billfitzmaurice]

I saw a guitar cab designs from Bill Fitzmaurice on his website: toe'd in and "kick backed" cab designs for 2x10, 4x10, 2x12 and 4x12 cabs.
Wouldn't vertical array...be better?

It would. Did you read the design intent?

guitar cabs have very narrow dispersion in the mid and high frequencies. To compound matters they’re usually placed on the floor just a few feet in back of the player, so those directional frequencies pass around knee level. Even worse, to ‘look right’ beneath an amplifier that’s 20 to 24 inches wide, dual driver cabs place their drivers horizontally. This narrows the horizontal dispersion angle even more, and causes comb filtering in the highs. In an audio engineering course on how not to build a speaker the typical electric guitar cabinet would be around the top of the list.
The simple solution is to vertically array the drivers, which would widen horizontal dispersion, eliminate combing and put the source closer to the player’s ear level, but the resulting tall, thin cabinet would ‘look funny’ with the amplifier overhanging both sides. Guitar players themselves have never had a problem with looking funny, but they do draw the line when it comes to how their gear looks. Enter Plan ‘B’: the cross-firing XF guitar speaker.

The same physics apply to bass cabs. But cross-firing drivers reduces the cabinet volume, which reduces bass response, so I don't offer an XF bass cab. Besides, the larger internal volume required for bass drivers makes a skinny cab unnecessary anyway; the narrowest I do is 20 inches, even loaded with tens.

but bill has said that you can aim cabs crossing the stage in a 45 degree angle to get better dispersion.

Yes, so long as the two cabs are stacked above one another, which keeps the overall acoustic footprint as narrow as possible.

 

[René_Julien]

It would. Did you read the design intent?

guitar cabs have very narrow dispersion in the mid and high frequencies. To compound matters they’re usually placed on the floor just a few feet in back of the player, so those directional frequencies pass around knee level. Even worse, to ‘look right’ beneath an amplifier that’s 20 to 24 inches wide, dual driver cabs place their drivers horizontally. This narrows the horizontal dispersion angle even more, and causes comb filtering in the highs. In an audio engineering course on how not to build a speaker the typical electric guitar cabinet would be around the top of the list.
The simple solution is to vertically array the drivers, which would widen horizontal dispersion, eliminate combing and put the source closer to the player’s ear level, but the resulting tall, thin cabinet would ‘look funny’ with the amplifier overhanging both sides. Guitar players themselves have never had a problem with looking funny, but they do draw the line when it comes to how their gear looks. Enter Plan ‘B’: the cross-firing XF guitar speaker.

The same physics apply to bass cabs. But cross-firing drivers reduces the cabinet volume, which reduces bass response, so I don't offer an XF bass cab. Besides, the larger internal volume required for bass drivers makes a skinny cab unnecessary anyway; the narrowest I do is 20 inches, even loaded with tens.

---

Yes, so long as the two cabs are stacked above one another, which keeps the overall acoustic footprint as narrow as possible.

Thanks bill, as usual you make me understand this stuff a little bit more.

My question was why the guitar cabs weren't designed in vertical array... AND kickbacked... AND crossfiring.
I know one thing: that would be complex to design and make.


... on the bass cab vertical stacking..

So, suppose you have two 2x10 cabs, you stack them vertically, it is a good idea to twist them? Like they are crossfiring... but on a different spot on the vertical plane.
Perhaps even placing them off center. (Like if you twist the top cab to the right, offset it to the left.)
??

 

[billfitzmaurice]

My question was why the guitar cabs weren't designed in vertical array... AND kickbacked... AND crossfiring.
I know one thing: that would be complex to design and make.

The original cabs of the 1950s were designed with no regard to acoustical engineering concepts, because the guys who designed them were not acoustical engineers. They literally just stuck some drivers in boxes. Dispersion was never considered, because they didn't know what dispersion was, let alone how driver placement affected it. The PA guys knew, but for whatever reason guitar and bass cab designers did not avail themselves of what the JBL/EV etc. guys knew.
Sunn did some cross-fired guitar cabs, guitar'd players didn't buy them because they looked funny. See above.

... on the bass cab vertical stacking..

So, suppose you have two 2x10 cabs, you stack them vertically, it is a good idea to twist them? Like they are crossfiring... but on a different spot on the vertical plane.
Perhaps even placing them off center. (Like if you twist the top cab to the right, offset it to the left.)
??

That's what Jimmy and I referred to above.

 

[RevNigel]

Hi Bill... Good to see you around.. I've bought a whole stack of plans from you some years ago and have built a handful of designs you've created. I will agree that Horn Loading is the way to go.. Cheers.

 

[unclekebm]

Tame the lows, angle it up