Gregerst

iTrader: (1)

I'm going to be switching from my single JBL GTO 15" sub to two AE IB15's pretty soon. Just waiting for the subs to get built n shipped. It was pretty easy to build the baffle for the single sub and mount it to the cross braces on the back seat frame because there was plenty of room but with two 15's I don't think this will be possible. So I'm in need of suggestions on how to securely mount the baffle to the car. I've seen L brackets mentioned on here and I think IHC is using them but I don't know how or where they're used. Pictures would be nice if anybody has any suggestions.

BlitzBlackGSXR

I hate cars is the man you want to talk to . He has that same exact setup so he would be the best source of info . Or you can search in google and add acurazine to end

pohljm

yes you will need to anchor the baffle from the perimeter with brackets as there is nothing really left after (2) 15's to allow you to mount to the diagonal braces.

Gregerst

iTrader: (1)

Thanks for the responses. Once I get the new baffle with sub holes cut out I'll see what my options are. Thickness will be 3 x 3/4" MDF. Not sure if that will matter though. Maybe I'll post some pics for the benefit of any future IB installs. Too bad we can't see any of pics that IHC posted though.

rich20730

I had the same issue when I switched from a single 12" IB to two 12's. I considered doing the L-brackets, but I had some concerns about how to attach them. I didn't want to use screws and risk puncturing my gas tank, and something like JB Weld seemed too permanent.

What I ended up doing was using a couple MDF scraps as spacers between the the braces and the baffle.

Here are some pictures. With 15's you'll have less room to work with, but I think you should be able to fit it. If I would have spaced my cutouts closer together I probably wouldn't have needed to modify anything.




Another option would be to rear mount the subs. If you're planning to do three sheets of 3/4 MDF that should probably give you enough clearance between the subs and the braces.

I'm currently working on a rear mounted IB setup with a couple of Stereo Integrity HT 18's for my home stereo




On a side note, unless it's for clearance issues/recess mounting 3 sheets of 3/4" MDF is probably overkill. Two should be plenty.

Gregerst

iTrader: (1)

That's pretty much what I did with the IB I have now. I might be able to get to work with two 15's if I go out as far as I can on the cross braces I'll play it by ear. I prefer to stay with front mount bc it'll take up less trunk space.
With the 3 sheets of MDF I'm recess mounting and the 3rd piece will actually be cut shorter than the other two and will be used to give it a little extra strength.
Those HT 18's ought to sound good is it going in the ceiling?

rich20730

Looks good! Yea I think if you put the spacers vertically and just use the holes on the outside of the braces it should free up a good amount of room.

Yep, about to head up to the attic right now to cut a hole in the ceiling :thumbs up:

I hate cars

I'll see if I can get my pictures back up. Not sure if the host exists anymore. If not ill just take some more. I mostly used L brackets around the parimeter. On the too there was room to get a couple nuts and bolts through the sheet metal and into the baffle. You don't want to mess with the braces since they greatly enhance the torsional rigidity of the car and you don't want to attach to both the perimeter and cross braces or you'll end up with squeaks and crackling wood.

When you get it running you have to try the IB15 full range. You won't believe how high they will play and with great detail. It sounds like you have rear fill playing full range.

Gregerst

iTrader: (1)

Thanks for the info IHC I'll keep all that in mind. What do you think about attaching it from the front top/bottom with flat metal brackets?

Yea I'll try them full range. One thing I want to be able to do with this system is get the bass to sound like it's coming from the front. I had a system like that years ago I didn't do anything special it must have been the the vehicle, box etc everything just came together and it sounded awesome. Not sure if it's just making sure phase / cancellation isn't an issue or is more about time alignment or something else?

Gregerst

iTrader: (1)

So I got the baffle built for my two 15" subs last week and mounted it in the car over the weekend. I'm very happy with the IB15's the sound quality is Amazing. I got to really try them out this morning with last night's snow storm the traffic this morning was brutally slow and made my usual 30 minute commute to work turn into 1 1/2 hours. But hey that just gave me more time to enjoy my new sound system. When I finally arrived at work I didn't want to get out of the car. I think the bass was getting better and better maybe the subs were getting broken in.

I thought I'd post some pics of the baffle and the install maybe it'll help somebody else. This definitely is not my best work. I basically had to build this in my laundry room as the outside temp last week was sub zero and I don't have a heated garage. I only had a cordless circular saw and jig saw to make the cuts with and it was all done free hand. Having said that it came turned out decent and the main thing is baffle very sturdy and strong. So on to the pics.

The front of the baffle.



The back of the baffle.



Metal L brackets, sheet metal screws and lag bolts. These were used to secure the sides of the baffle to fender well / strut brace.



Flat metal bracket. This was used on the front of the baffle and attached to the rear deck.



This shows the side view of the same flat metal bracket. I bent it to fit the contour of the rear deck / baffle.



Baffle mounted to the car showing the placement of the four L brackets.



The flat metal bracket mounted to the rear deck and front of the baffle.





With trim pieces installed.

Gregerst

iTrader: (1)

Here's a couple pics of the back seat. To allow for more air flow from the subs I removed the ski pass. To protect and hide the woofers I put a piece of thick metal mesh wrapped in speaker cloth in it's place.

rich20730

Looks good!

Gregerst

iTrader: (1)

Thanks. When it warms up I make another baffle that looks a little nicer maybe incorporate a beauty panel or something else to give the woofers some protection.

I hate cars

Yours looks nearly identical to mine, brace in the middle and all. Except you cut the carpet much better and it looks neater. I showed my fiancee one of the pictures and asked her what it was and she said "your subs" lol. You have a little more spacing between your subs, not much and we both used the same L brackets as well. Looks good lol. Still liking it?

I went out and did some tuning with my PS8 last night and these things do so incredibly well. On rock they have great punch and quickness and even to this day it surprises me when I'm used to no low bass, just punchy stuff and I put in some bass heavy music that they drop down like they do. It's not often you find a sub that combines every good quality into one.

The only reason I'm thinking of the 13W7s is just because they have a "different" sound that I love. I'm keeping the 15s though, just in case I want to put them back in. It will suck to go from 34lbs totoal to 100lbs total. The JLs will also have 2db more output but I'm going to need 2-3x the power to push them. As I'm typing this I'm thinking why the hell would I do this but the simple answer is I get bored.

Gregerst

iTrader: (1)

The strut towers and front deck seemed like the most logical place to mount it to. Yeah the subs rock. I'm still amazed at how clean they sound. I've played all the different genres and everything sounds good with very little adjustment. you know their digging deep when it's just pushing air and no sound. I've been worried about driving them too hard so for now I've been cautious. Even so measuring the SPL with audiotools I can hit 110 db without trying. Now I need a processor and eventually get some hard hittin mids up front.

How many 13W7s are you planning on running?

I hate cars

They use a shorting ring and a suspension that mostly limits overtravel. You pretty much don't have to worry about damaging them from bottoming once or twice by accident. I accidentally hit mine with 1,000w on a 16hz sine wave when I first got them and they survived with no bad noises. It's not recommended but they do have two lines of defense from hard bottoming.

My 12W6 would hard bottom at about 2" of travel. No sort of cushions since it's not an IB sub like the AE. That's why I'm going with the 13W7, 32mm one way linear travel, nearly 5" total mechanical travel, they're probably never going to bottom out.

Gregerst

iTrader: (1)

Good to know. When I get more comfortable with them I'll see how loud they can get.
32mm on those subs are crazy. For s & giggles I modeled them. They look ok but a pair of them are going to need about twice the power (1200w) for them to play as loud as the IB's and they'll need about 2000 watts to hit xmax. At xmax they'll only be 2db louder. The Qtc is lower though so you'll get that tighter sounding bass. Just seems like an expensive way to get there. But maybe I'm way off with my modeling.

I hate cars

That's what modeling would say but my experience and several others on Diyma differ drastically. I've run the W6 and 7 IB and the 12W6 only requires 220w to bottom in IB. It has the same xmech as the IB15. The W7 will exceed xmax around 400w I'm IB. You're not going to find a speaker that hits its thermal limits before xmax in IB. I don't know if the specs JL gives are inaccurate or what. I ran a Tempest X 15 and it was flat out less efficient in the subwoofer range even though it was rated as being more efficient.

These are two very different subs. Both have a flat Bl curve but the W7s is much wider. The Ae has the best inductance treatment period which is awesome. It has an extremely low MMS which I really like but the W7 is lighter than most as well. So the AE has some very cool features.

The W7 has a ton of cone area for its outer diameter. The 13W7 has almost as much cone area as a low cone area 15 with 32mm on way linear excursion and over 50mm one way me mechanical. Where these subs shine is the suspensions. They're second to none. The spider is as big as the cone and progressive. The surround is supposedly good for 5" peak to peak before peaking out. The AE is lacking in the suspension department but that's under stood since its a dedicated IB sub and more suspension would've compromised other areas.

Both subs are great, but I almost prefer the sound of the W7 *when in IB*.

Gregerst

iTrader: (1)

I think infinite baffle can be a bit tricky and hard to predict accurately. My system seems to act more like big sealed box more than a true IB. When I pop my trunk there's a definite decrease in bass output almost seems to go a little flat. Probably means I sealed the trunk well.
Good luck with those W7's. thats going to be a lot of weight on the baffle u might need to reinforce it a bit. The ID v4 might be interesting with 25mm xmax.

I hate cars

Interesting. With identical subs I get almost zero change with the trunk open or windows down except in the very lowest octave, lower than most music goes. I didn't seal the trunk, in fact I made sure they could breathe and be closer to IB by removing the vents. Now the trunk to cabin is a different story. That's sealed very well, including the rear baffle and 1/4 panels.

I didn't want the trunk sealed because I prefer the sound of a lower Qtc. Tighter and snappier and more really low sub bass. With the low Fs of these subs, honestly the main reason for giving them as much breathing room as possible is for low end efficiency. Still though, getting them to the "critically damped" .5 Qtc was important for me for the best possible SQ.

If you lose output with the trunk open it sounds like cancellation. This will especially happen if you have the windows down or if the car is in an enclosed space like a garage and even a covered parking structure.

Displacement is displacement and output is determined by displacement only when sealed or IB.

Gregerst

iTrader: (1)

Yep out in the open if I pop the trunk the very low bass notes tend to go slightly flat. I don't know if it's less output, change in the sound or both. It's not drastic but noticeable to me nonetheless. Next time I have my RTA hooked up I'll experiment with it. My trunk is completely sealed between it and the cabin and between the trunk and outside. I spent hours sealing up every nook and cranny when I was deadening the trunk. I did leave the vents alone though. But with the plastic carpeted trunk liner obstructing them I wonder just how much air can really escape? Could it be acting like an aperiodic membrane?
I may try removing the vents and the carpet liner and see if I like the sound better.