Modify 2x12 horizontal guitar cabinet

grinder

Hello,

I 'm considering modding my Jet CIty JCA24S+ 2x12 guitar cabinet:

https://www.jetcityamplificationstore.co.uk/wp-content/uploads/2014/02/JCA24SPLUS_Front-325x325.jpg

in order to have it in an upgright/vertical position (will also get new speakers since I do not like the ones that it came with). What I am trying to understand is if in such a way the speakers would have to be dead centre in the baffle rather than offset as it is right now. Or maybe do it like the Orange vertical cabinets where both speakers are offset like so:

https://i.pinimg.com/originals/52/96/ee/5296eee58be15098543ebd2771b0d8f2.jpg

I tried to Google this issue, but wasn't successful in getting some good answers. Therefore, I 'd appreciate your thoughts. Thanks!

mart

Have you tried just turning it on its side? There’s probably no need to move the speakers at all.

grinder

Hi Mart. Well, yes, I 've already done that, but I am wondering if further modification is required for better results.

grinder

Here's one thread that discusses the topic of speaker placement in a guitar cabinet's baffle, but there doesn't seem to be a definitive conclusion:

https://www.tdpri.com/threads/mounting-a-speaker-to-a-baffle-question.342921/

mart

I’m pretty sure that, from a physics point of view, the most significant thing is the placement of your ears (or your listeners’ ears) relative to the speakers. If your 2 speakers are aligned vertically, then its sound will vary if you move up or down. If the speakers are aligned horizontally, then it’ll vary when you move horizontally. If you’re standing or walking around, then your ears are likely to stay at the same height, so the vertical arrangement will be more consistent.

If your speakers are slightly offset, then the sound will vary a lot when you move up or down, and slightly when you move from side to side. In a gig situation (remember those!) that will have some impact on what your punters here, but much less than in a horizontal cab.

But there is no rule about where you need to put your ears to make the cab sound “best”, the physics only really tells you what will make the sound different.

So move your head around, see where sounds best, and adjust your cab accordingly.

grinder

Thanks Mart. What you say makes sense. I may experiment with some 12mm leftover plywood I have from a previous project.

ICBM

mart is right. The physics of sound dispersion from a two-speaker cab actually produces the opposite of what you would intuitively think from looking at it - the sound is spread out at right angles to the line between the speaker centres, not along it - this is the basis for the ‘line array’ speaker towers you see for PA.

A horizontal cab is really the wrong way to do it, as it has a narrow vertical beam, so the sound falls off rapidly (and changes tone) as you move to one side of the cab - whereas a vertical cab has a flatter horizontal beam, which gives better dispersion in the room and a more consistent sound as you move from side to side.

It is a bit counterintuitive since it looks like a horizontal cab should spread the sound horizontally, but it really is the other way round! It seems to be quite difficult to convince most guitarists of this though... but vertical cabs are at last becoming a bit more popular now.

The placement of the speakers on the baffle shouldn’t make much difference to the sound of the cab - guitar cabs usually aren’t properly designed from an audio physics point of view at all. As long as the speakers are in a vertical line you’ll get the best horizontal dispersion, so I wouldn’t go to any trouble to make a new baffle.

grinder

@ICBM Thank you!