Quoted from DavidNOLA:Dave, there is mention of it but not a ton of discussion about the engineering relationship of speaker and cabinet.
Obviously, a high-quality sound system never has two 4-5" speakers in a cab the size of a back box.
I guess it would be hard to find a satellite speaker that would fit, but what do you think of this?
Take R-Max foam board and put it where the speaker assembly and the transom glass meet, then put another piece between the speakers from that horizontal piece to the bottom of back box in an effort to keep some sound from bouncing around the back box and try to divide the speaker outputs.
A kind of tacky attempt at creating a 'speaker cabinet' inside the back box, but foam board is cheap! easy to try.
Your speaker fights were in a box. This would be a little closer to that.
Do you think this would be helpful? Thanks.
Great question. The cabinet and backbox are less than ideal enclosures. We can still get good and worth while results working with what we have. I did look at some JBL studio monitors and was thinking it would be pretty cool if they could shoehorn into the backbox somehow. But man that would be allot of work. Super cool though..
But back to working with what we have. Without a calibration microphone, it will be difficult to really build the correct size enclosure for the chosen speaker set. That's kind of allot of work too.
There are some things we can tighten up a bit.
The backbox is quite large for those drivers in general, and it's just full of air leaks. Another issue, just as important, is that it's a single open enclosure that 2 drivers, running different signals are sharing airspace in. The cabinet speaker, which runs a different third signal, also shares airspace with the back box too due to the big cable openings between them. This sharing of space means as different signals play from each speaker different pressure waves are created behind the speakers. Leading to distortion and cancellation. So putting them in their own airspace would produce some improvement. For the smaller backbox speakers figuring out the exact volume of a box etc. will not be as important as it would be for a sub woofer. So just giving them their own airspace would be a plus. I have been thinking about a solution for a while now, something I did earlier was meant to be the foundation for it. I'm just not there yet, as I got distracted by shiny things.
There is nothing wrong with your thoughts on sectioning off the speakers with foam board. It should work pretty well. You may have to move the power supply up or just enclose that portion too. The only other thing I'd think about is try to close off the bottom area because of the big holes that go down into the cabinet.
For the cabinet - There are a few considerations depending on what you want to do with the speaker. Let's say you want to run a subwoofer in there. (80-160hrtz ish and below) there is a big airspace available, which is nice for a sub. However; it's full of air leaks and holes - hardly the best scenario. But not exactly bad either. I've gotten some great real word results with it. I have a friend coming over to check out what I'm up to - and I'm pretty sure he'll poop himself when he hears it. We can enclose the subwoofer inside the cabinet, this wouldn't be too hard to do. But now we need to design an enclosure with the correct internal volume. If we want to port it, then that is a big can of worms - more measurements, more work, it's all speaker specific too. And if we are doing all of this without using a calibration microphone to truly measure the results then we may just be chasing our tail. Did we just go to far with all of this, it is a pin Afterall? @Good_Times took a bit of a different approach - he looked at what types/specs of subwoofers were available that would operate better in a free air enclosure and went that route to great results as well. One of the advantages of running a sub woofer in this location is there will be minimal frequency overlap with the backbox speakers and very little alignment issues that may create distortion. You also get that real nice tactile feedback, like a shaker on roids.
I guess in summary - I agree with you that the enclosure situation stinks. But it's not terrible either, and should not stop anyone from making some of the mods listed here. With real world testing, there is still significant benefit to make it worthwhile. It's the 80/20 rule. 80% of the results can be had for 20% of the effort and expense. The last 20% will take 80% of the budget and effort to achieve. Doesn't mean we can't chip away at them though, keep exploring the rat hole, find solutions and where the reward vs effort make sense.
If I can get my hands on a Rush LE, I'll break that rule and do a ton of things that defy all common sense.... 3 Subwoofers, backbox enclosure, light show topper.....