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View Full Version : Triple Baffle 18's Countersunk 1.5"



SHiZNiLTi
06-22-2007, 12:20 PM
I'm definitely making the box for my RE MT 18's this weekend. I've got a question about the baffle.

Below is a MSpaint sketch of what my rear cargo section looks like. The rear seats are adjustable and fold up and down. I'm going build a wall behind the rear seats and was thinking of possibly doing a triple baffle with the subs countsunk 2 layer deep.

I believe the RE MT 18's xmax is 18mm which is .70" If I do this do think it will allow me to rest the back of my rear seats onto the front of the box without having the subs during full excursion touch the seat?


The Blazer...
http://img119.imageshack.us/img119/6122/blazersideshot2se3.jpg

The MSpaint sketch of rear cargo area...
http://img83.imageshack.us/img83/8386/blazerru6.jpg

The Video of the Box...
http://i113.photobucket.com/albums/n228/SHiZNiLTi/th_bracingwall.jpg (http://s113.photobucket.com/albums/n228/SHiZNiLTi/?action=view&current=bracingwall.flv)

If it's not enough to protect the subs surround from hitting the rear seats I can go with my orignal idea of making custom rear seat hinges that will prevent the seats from leaning back all the way.

Let me know what you think about this idea.

Pl8er
06-22-2007, 12:23 PM
Nice truck man! Sorry can't help ya on the question, but wanted to give the props! Nice vid too, like the ladies at the end ;)

skadude016
06-22-2007, 12:33 PM
no more 6th order idea. to bad. Ill be starting my RE MT 18" wall sooner or later.

You should be fine doing that. but there is a chance the surrond may touch

djman37
06-22-2007, 12:33 PM
instead of making whole baffles and making your box that much heavier, why not use rings on the outside as seat barriers?
I'd also try to run at least 1 dowel from front to back as high as you can before the back slopes in.

SHiZNiLTi
06-22-2007, 12:56 PM
Nice truck man! Sorry can't help ya on the question, but wanted to give the props! Nice vid too, like the ladies at the end ;)
LOL, thanks. Download DiVx and check these Benny Benassi (http://stage6.divx.com/videos/search:benny+benassi) music videos, they are amazing!


no more 6th order idea. to bad. Ill be starting my RE MT 18" wall sooner or later.

You should be fine doing that. but there is a chance the surrond may touch
I'm going to build this standard box first, then when I get all moved into my new home and have shop setup I'll take my time and build the 20cuft 6th order. I cant wait to see your RE MT Build log. Do you have the subs allready? Can you measure the height of the surround so I can figure out if the subs during full excursion will touch or not. Is the max the excursion 18mm? thanks.


instead of making whole baffles and making your box that much heavier, why not use rings on the outside as seat barriers?
I'd also try to run at least 1 dowel from front to back as high as you can before the back slopes in.
Thats a great idea, never though of that. I could still do the standard double baffle that I originaly planned to do and counter sink them (1) layer then just make 1 or 2 set of rings with really nice routered edges. I'll take your advice on that dowell move. It does make sense to have more bracing in that area especially since the angle cut doesnt have any bracing on it.

skadude016
06-22-2007, 01:15 PM
Its gonna be for a single RE MT 18. When I was playing with it free air it looked alot more than 18mm xmax :fyi: but ya man I can measure for ya. you just want the height of the surround?

skadude016
06-22-2007, 01:20 PM
Looks to be .75"

SHiZNiLTi
06-22-2007, 01:22 PM
Its gonna be for a single RE MT 18. When I was playing with it free air it looked alot more than 18mm xmax :fyi: but ya man I can measure for ya. you just want the height of the surround?
Yes height of surround. That way I can add suuround height with Xmax to get the total that I need to make for clearance.

*edit* thanks for the quick measurment posted above :D

Ok then, Im pretty sure if I countersink the subs in a standard double baffle and make (1) set of rings that will give me enough clearance to safely lay the seats back without worring about the surround hitting the back of the seat. since 18mm = .70" + a .75" ring is 1.45 and Im gonna have 1.5" total I should be good.

Can some quickly verify the 18" RE MT xmax? For some reason reaudio.com doesnt list it.

I wonder how wide I should make the rings. Any ideas what you think would look best. Im thinking 1.5" wide with a nicely rounded over edge.

squeak12
06-22-2007, 01:25 PM
Put the rings inside of the baffle so that it will be flush on the outside and save weight.

SHiZNiLTi
06-22-2007, 02:06 PM
Put the rings inside of the baffle so that it will be flush on the outside and save weight. inside?

I was planning on doing somethign like this, the ring would have rounded edges on the top, this is 1.5" clearance from sub mounting surface...

http://img526.imageshack.us/img526/9423/doublewithringtophs7.jpg

http://img146.imageshack.us/img146/7584/doublewithringdx8.jpg

SHiZNiLTi
06-22-2007, 02:25 PM
Does anyone know the xmax of a RE MT 18?

tez4life
06-22-2007, 03:00 PM
http://www.reaudio.com/specs.html

Try that Shiznilti, hope that helps and excellent build in progress, looking foward to the results!

tez4life
06-22-2007, 03:00 PM
Crap, i thought I saw it on there, my bad dawg.

djman37
06-22-2007, 03:10 PM
Does anyone know the xmax of a RE MT 18?

you're gonna need xmech anyway.

Chevyaudio
06-22-2007, 03:14 PM
you're gonna need xmech anyway.


Yup ;)

sku
06-22-2007, 03:55 PM
Does anyone know the xmax of a RE MT 18?

I don't think RE ever released the T/S specs for the MT?

I can say though that my MT 18 on my MA-HK4000D barely moves (even at full output)...

SHiZNiLTi
06-22-2007, 04:05 PM
Ah yes, it looks like xmech is what I need. It also looks like Xmech is allways a lil more then the Xmax...

Xmech - Maximum mechanical limits of the subwoofer. ie when the physical suspension stops the driver from moving (surround, spyder) or when the coil slams into the back plate.

Xmag - When the BL produced by the coil has reached 70% of it's rest value.

Xsus - Excusion limit due to the mechanical suspension (similar to xmech but doesn't include the coil landing on anything)

Xmax - The lesser of Xsus or Xmag. Or a measurement based upon the length of coil in the gap.

BUT I've also read that...

Xmax is center to peak (one way)
Xmech is peak to peak.

^if the above is correct then it is Xmax that I need not Xmech.

Anyone know the Xmech of a RE MT 18?

Any more clarification on this is highly appreciated

Thanks! :D

SHiZNiLTi
06-22-2007, 04:18 PM
I don't think RE ever released the T/S specs for the MT?

I can say though that my MT 18 on my MA-HK4000D barely moves (even at full output)...

lol, if thats the case, I'm making too much of a big deal outta this and will just do the double baffle, subs flush with a ring.