Removable baffle and back panel sealed boxes for tests

[Ricci]

I figured this might interest a few people, since it's a little bit different from the norm.

I've been putting a removable baffle on my last couple of enclosures trying to get the design worked out and refining it each time. The first one worked, the second was better and these are a little better still. The reasoning behind it is because I like large diameter, big drivers and they are usually heavy as hell. I've pinched a few fingers putting them in and removing them and also had plenty of screws and T-nuts strip out. It sucks. I figured this way I can yank the whole front off of the box and do whatever I need to do in there. The other reason is so I can use the enclosure in multiple configurations by simply making new baffles. I'm also going to have some removable bracing in these on the back panel. I plan on using these to test a whole bunch of things. Different drivers, port configurations, port compression limits, effects of bends in ports, port flaring, stuffing and lining effects, bracing effectiveness, dual opposed driver enclosure vibration cancellation, blah, blah...

I'll be building 4 total. The enclosures are about 270L (9.5 cu ft) internal volume after accounting for bracing and driver displacement and are 23.75x 23.75x 37 which is about right for a the drivers and amplifiers I'll be using in the finished system. I'm using 3/4 BB ply single thickness for the sides and bracing and double thick for the baffles. 2x2's are used for bracing and the baffle mounting foundation. This is the progress on the first 2 so far.

[Ricci]

Further Build pics...

[kensaudio99]

What vehicle are those 4 boxes going in?

[Ricci]

No vehicle. They will be in a home theater set-up. I might throw one or 2 in the back of my SUV for fun once or twice though. I think I can fit 2 with the seats down.

[Ricci]

[raz0rx]

Sexy, throw some cash my way, I know you have some extra :P

[sri3850341]

awesome.... crown amps for power??

[Ricci]

Amps will be 2 of these on 220v lines...











I've got a few Crown's and Crest's too, but they are on other duties...

[Ricci]

Here's the temporary home for the first pair of enclosures at my rehearsal space while I work on the second pair and get the room at the house ready to go. My dumbness forgot to get any pics before I put them in place under the EV's so I'm not going to pull them back out just to get some. BTW this combo x'd at 70hz will kick out the jams. I had a little fun playing with it last night.


Here's the parts list for one of these enclosures...

2, 4x8 sheets of Baltic Birch ply
4, 8ft long 2x2's
1 large bottle of wood glue
1 Duplicolor roll on truck bed liner kit
2 packages (40ft)of 1.5" truck camper foam gasket
8 cheap poly cotton pillows
1 NL4 Neutrik Speakon female terminal
7ft of 10ga wire
4 black, cheap drawer handles
8, 10/32 allen head cap screws
8, 10/32 long T-nuts
25, 1/4x20 hex head bolts, 3" long
25, 1/4x20 long T-nuts
25, 1/4" flat metal washers
25, 1/4" neoprene washers

[freemind]

Damn! very nice Build quality.

[Ricci]

Thanks.

Enclosures #3 and 4 will be done tonight. I just have to Wire them up, stuff em and mount the drivers. I'll post a few more pics.

[Kryptonitewhite]

i saw your conclusions or test results from stuffing on HTS... didn't have too much time cuz it looks like it was extensive and there was a lot of info

just curious, how do the 2 xxx's on the bottom compare to the 2 pro audio up top?

[SCHMITTY]

It's all trash. Get rid of it. Give it to me in fact!

[Ricci]

Originally Posted by Kryptonitewhite

i saw your conclusions or test results from stuffing on HTS... didn't have too much time cuz it looks like it was extensive and there was a lot of info

just curious, how do the 2 xxx's on the bottom compare to the 2 pro audio up top?

Those aren't real subs bro...Those are 15" woofers EVX150B's. Those cabs are tuned to about 50hz or maybe higher. They basically run 50-400hz or so before handing off to the 10's. Those aren't anything real nice. They are probably 10years old, but they'll still melt your face off. They are probably louder than the XXX's above 60hz. Below that there is no comparison.

[Ricci]

Cabs #3 and 4 are basically done, but I have to wrap up a few things tonight (cross threaded one of the baffle mounting bolts on one cab last night). Bleh.

A few more pics.

[Ricci]

Bleh...More pics with 3 & 4 in place. I've got to pull out cabs 1 & 2 from under the PA and load them back in the jeep to take back home. They are over 200lbs each so it's not something I'm looking forward too. Still got a lot of work to do on the room before things are "operational".

[Fallen]

Epic moofas. Have you had any problems with room modes? have you tried placing these apart from each other. Room modes are really pissing me off lol.

[Ricci]

I don't even have them hooked up yet. I've gotta get a new reciever put in and yoink one out of another system to put in this room and then wire everything up. Gotta swap out the cable end on one of the amps, get the other 2 cabs in there and move my speakers from another system in there too. I don't have any idea what this room is like acoustically yet. I've never had a sound system in there. It used to be a game room that we have recently remodeled. I'm still trying to figure out what exactly my placements are going to be.

I plan on working on it tonight for a bit. Hopefully I can start getting things calibrated and start measuring things next week. I'll let you know how it goes.

[Fallen]

Right on. Well good luck with it.
That was one thing I hated about my tapped horn in a small room, there were prominent modes. It was alright for movies(ok it was nuts for movies), great for parties, but for music some notes were missing....until you took two steps back. Or to the left or right. To more or less minimize the problem the horn was used as a coffee table, so we were in the near field, so the modes weren't as bad. Hopefully you won't have this issue with 4 18s

[Kryptonitewhite]

Originally Posted by Ricci

Those aren't real subs bro...Those are 15" woofers EVX150B's. Those cabs are tuned to about 50hz or maybe higher. They basically run 50-400hz or so before handing off to the 10's. Those aren't anything real nice. They are probably 10years old, but they'll still melt your face off. They are probably louder than the XXX's above 60hz. Below that there is no comparison.

LMMFAOROTF! I was kidding

Always an open bottle for comparison pics... nice!

[Ricci]

Fried one of my Pl9.0's with War of the World's DTS. Sux balls. Gotta send it in to be fixed. I'm using the other in the meantime. They are dumb powerful, but I guess I just pushed it too hard. I can't help it, I had to see how far it would go before the clip lights flashed. I got em to light up all right . Just once and that was all she wrote. I think the high volume <20hz content took it out. Apparently it just kills a lot of amps. The subs still had a bit left.

[Fallen]

Well now you know.
:P any chance you know what the SPL was when she gave out?

[Ricci]

I don't know for sure what the levels were, but if you are at calibrated REF level and have all bass redirected to the LFE channel it is possible to hit theoretical 121.7db peaks, but not likely. I was running the bass 2 db hot though, so I was probably in the 120db range at the listening position. May not sound like much, but that ain't in a car and the majority of that output is below 30hz. I don't run a HPF and that soundtrack has vicious bass down below 10hz in some parts.

I'll see if I can get a spectrum reading for you later.

[Fallen]

No, that does sound like a lot.
That's pretty insane.
Just wait till you get a tapped horn in there(:P You should make one for your XXXs...might need 10000l though lmao. Put it in your attic)

[Ricci]

Original nearfield placement FR. Yeah it really was that good....





Put one of the subs on a shop dolly and moved it around measuring responses until I found the best spot. Then I added the second one to the mix and rolled it around checking the combined response until I got the best location for it. After that I level adjusted the subs to match the mains output and then adjusted the crossover until I got the best blend between the subs and mains. After that I tweaked out the distance setting (phase) to get the best blend through the xover. Here is the result of all of that.

Much better.




Response average over 7 possible seating positions.




After I add subs 3 and 4, when I get the repaired amp back, I should be able to flatten things out even further. From there I'll EQ the average response over all of the 7 possible seating positions (46hz room node) and I should be golden.