Increased dispersion with a board?

[kringle77]

Awhile ago, just as an experiment, I took a 2'x4' sheet of plywood and set it up perpendicular to my 8x10 cab, with the sheet setting in the center of the cab. I then turned the plywood at a 45 degree angle, forming half of a horn. This blocked the high frequency sounds of the left side of the cab and allowed the right side to project everything. I backed away from the cab and noticed immediatly that the horizontal dispersion greatly improved. Have I come up with something useful? Just imagined it? Created more problems? I just thought it was an interesting experiment.

[billfitzmaurice]

Originally Posted by kringle77

Have I come up with something useful? Just imagined it? Created more problems? I just thought it was an interesting experiment.

The dispersion increased because the board eliminated the midrange content from the blocked speakers. What your experiment confirmed is why drivers should not be placed side by side.

[kringle77]

Thanks for the confirmation bill. In that case, I'd say this could help some players with traditional cabs get better coverage. Im going to assume that you would get the same results setting up a 90 degree horn in front of one side of the cab so, using one piece of plywood would be just as good?

[billfitzmaurice]

Originally Posted by kringle77

Thanks for the confirmation bill. In that case, I'd say this could help some players with traditional cabs get better coverage. Im going to assume that you would get the same results setting up a 90 degree horn in front of one side of the cab so, using one piece of plywood would be just as good?

I don't find lugging around a 2x4 piece of plywood to address an inherent design fault as a useful option when you can just do it right in the first place and build the cab with vertical drivers, or low-pass filter the drivers on one side of the box.

[KJung]

Originally Posted by kringle77

Thanks for the confirmation bill. In that case, I'd say this could help some players with traditional cabs get better coverage. Im going to assume that you would get the same results setting up a 90 degree horn in front of one side of the cab so, using one piece of plywood would be just as good?

Sometimes we think too much about the wrong things Have you heard a Henry 8x8 or your cab out in a room? I've heard so many 410's and 810's with no PA support out in so many rooms, and the narrowing of the upper mids for bass guitar backline is relatively trivial. Some of the greatest sounding bass tones out in the room I've ever heard were delivered without PA support from an EdenXLT, a GoliathII, or a Henry 8x8 (although only heard that cab in a few contexts).

Remember, we are only really talking about the upper mids below where the tweeter kicks in. The meat of the bass tone is minimally impacted,

If for some reason a bit of improved coverage to the sides of the cab in this region is key to your tone, there are plenty of options available.

I would just relax and play. My guess is, that cab KILLS out in the room, and sounds relatively even where it is important with bass guitar backline.

[kringle77]

Don't get off track here guys. Ken, I was talking about my old 8x10 not my 8x8. Although they do share the same design flaw. My new 8x8 killed at the first gig! Yeah, it's a good idea to do it right the first time. But, all I was saying, is that someone who already had a cab like an 8x10 could do what I suggested if they needed better dispersion. As I have stated a zillion times, I have great success using my cab for the bulk of my tone and volume and then use the pa tops to help disperse the sound around a room because even with proper 3-way cabs, all that dispersion doesn't amount to jack s##t when you have a sea of bodies in front of your cab. I got the answer I was looking for.

I'd like to have some guys try this and report back.

[kringle77]

Oh, I would have suggested high passing the top two vertical right hand drivers of an ampeg sealed 8x10 and running the other 6 lowpassed but, then you have to deal with a woofer putting out lows in the same enclosure as the other woofer that is only doing highs and thats not good. Although, if you could find some of those foam top hat looking chambers to stick in there for a mid chamber, that could work really well. I don't know what those things are called but, I have one in my old LDS cab.

[KJung]

Originally Posted by kringle77

Oh, I would have suggested high passing the top two vertical right hand drivers of an ampeg sealed 8x10 and running the other 6 lowpassed but, then you have to deal with a woofer putting out lows in the same enclosure as the other woofer that is only doing highs and thats not good. Although, if you could find some of those foam top hat looking chambers to stick in there for a mid chamber, that could work really well. I don't know what those things are called but, I have one in my old LDS cab.

Alex (Barefaced) has a cool 'fix' for this issue. There is an active thread. He lo passes one side of the 10's so that the bass is coming through all the drivers, but the upper mids are coming from a single vertical array. Pretty cool. He takes it one step further by swapping out one of the regular drivers with more of a guitar type 10 next to one of the lo passed drivers, so you can get some of that classic break-up found in the old fridge cabs.

That is pretty cool, and kind of does what you are looking to do with a more traditional 810 or 610. Slick!