[JohnL2001]

OK, I had a thread going here on the forums about my situation with subwoofers and i had decided to go with a vented enclosure. i have changed back to Infinite baffle so....

its T time, and this is what i have decided to do although i have said i was NOT going to do this.

Im going infinite baffle!
(1) because as i have toyed around and learned more about winisd i have found the tools useful on paper and i want to see just how close they model to real life.
(2) Infinite baffle Output is pretty much spot on with the the vented design with the most output in the bass region that i could come up with WITH THE CORRECT EQ APPLIED, by the way that thing has enough boost built in to pound like a jackhammer off of 1 watt much less the 1500 i am supplying it with at 2 ohms. (obviously i know it wont get 1500 all the time) AND i did take it past 50hz to 80hz lowpass and apply the same flat (ironically boosted to flat) eq there as at 25hz roughly, the difference i ended up with between vented and IB was so miniscule its not even worth the enclosure build.
(3)Its going to be so much easier to just build a damn good baffle, rather than a 16ft cubic ft ported design that will have to be custom molded to every contour of my van to save as much space as possible and i would still need to come up with a port design ... because im overboard and want even the port to match the shape of the design (no plain square or circular ports)

so here is my max output and TFM graph, im giving it all i have on paper or better yet in winisd, to get an approximation of what i can do with dsp in the car, dsp in the car should work even better than this if i have my thinking cap on here. I know my cabin gain frequency, or around about it, and i have built around it. Example is i didnt need much boost in the lower bass frequencies and that helps a lot when trying to limit cone excursion, and as far as cone excursion goes im not that concerned in fact i bet the SI ht18v3 actually has way more in it because that is LINEAR cone excursion and my guess is that most people ride around listening to music with the subwoofer way past linear excursion because of how easy it would be to miss a little bit of distortion in a noisy car environment..(and they use bass boost on a head unit)

So here goes, about to try this , sawdust /glue/fiberglass jelly/vinyl possibly... long weekend/job ahead wish me luck!

p.s. One of the graphs below is vented and one is IB... without anything but looking at the graph guess which one lol. I know some of you could actually tell by the graph but some couldnt.

 

[JohnL2001]

 

[JohnL2001]

k so i kinda snuck an extra 18 in there lol

 

[JohnL2001]

ok, so i got started on the subwoofer baffle yesterday finally. But , got nowhere near as far as i had planned given i needed to run around and spend money on things for the majority of the day unfortunately . needed hardware for mounting the subs (t nuts, allen head BLACK screws in a decent size) various tools i thougth would be handy to have, etc etc etc

Im lucky to have a wife thats not going to complain very much, i mean i am the bread winner of the house after all....she and my son even helped me put a 1/2" roundover on this front piece of the baffle, which was a chore and still had to be sanded given my router table is VERY small. If your married guys, a good woman is worth the world so i chose her based on stereo equipment and not totally superficial reasoning

Now, if youll think about the amount of force that two 18s put out at low frequency and the fact that most people double , maybe even triple baffle just a small diameter trunk baffle (~15") and for good reason, this means my ~48+ inch span of baffle is going to have to be even stronger. So the plan is one layer of mdf, one layer of oak 3/4" ply behind that (because you cant get any better sheet wood here) and i MAY add a 3rd layer front or back but the key is going to be using 2x4s for bracing. (which will be worked until they do NOT LOOK like 2x4s because thats just tacky!)

I had considered a thick steel baffle welded in but decided against it and may regret that. But i think it goes without saying around these forums that the more firm a baffle surface is the less output wasted on resonating the vehicle and the more focus on ACTUAL music energy.

so far i have removed the headliner (because its going to be rebuilt to accomodate the wall/recovered, removed the seats/midbass box/carpet and put down deadener and padding in the area where my midbass box and sub baffle will be, put the carpet ,box,seats back in . i.e. The floor is very stiff and dead in this van, although im sure soon ill be adding some type of road noise deadener down there. The roof of this van however? TOTALLY different story, if you knock on it it rings like a bell.....im going to have to order so much deadener i fear the wharehouse will be on backorder, but all in good fun.

I Then Worked on the baffle which itself takes forever to get a perfectly snug fit, but i DO have a solution to even the smallest air leak. On top of your average sound deadener sheets and making sure my baffle meets every edge no matter how many detailed cuts must be made (in my capability), i am going to line the contacting edges of my baffle with a nice foam rubber, nice firm but flexible expansion...................and where did i find this in a pinch yesterday? LOWES! plumbing aisle, 1" pipe wrap but not the cheap crap thats only foam i splurged for the $10 per 6 ft section actual rubber stuff lol . This stuff is definately strong enough to hold up and give or take 6" wide when flattened which is more than adequate since my frame for the baffle will be somewhere between 3.5" to 6" not sure yet, i kind of work off of a design i built on paper and go wild from there when im building.

The guy at lowes also showed me horse mats, which i have experience with, but man they have no give since they are designed for a 1000 plus pound animal to stand on HOWEVER these COULD make good sound deadening material on the floor of the vehicle to keep road noise down and would possibly be cheaper than the amount of deadener you would need to keep things extra quiet.....but i doubt ill go there since this cannot be applied to the roof I DONT THINK.

The thing im most certain of here is that i will essentially put a 4x4 post right between the subs on the rear of the baffle, and most likely end up using a home type framing method for my baffle (turn 2x4s so that the 1.5" edge contacts the rear of the baffle) since this is where the 2x4 is strongest. And i MIGHT build a brace around the subwoofer, im considering the idea of a cage/brace combo since i had planned to put a cage with a ton of holes in it around them to keep them from damage in the work part of my van ie things banging the sub during transit. We will see what i can come up with there as well.

well im rambling on and all over the place here, tiime to get some coffee in me, and get back to sawdust city. who knows may yap away a little more as i have my coffee

 

[JohnL2001]

Also, the thought of putting a texture on the baffle and then painting it to match has been on my mind since vinyl is probably going to be a real PITA in certain areas , but ill cross that bridge when i get to it.

It just seems easier to contour everything with a sander/fiberglass/resin/bondo then texture and paint rather than do all of the above anyway then try to wrap it with matching vinyl or carpet to me. My mind may change though as usual.

Oh, and ill be using a nut setter to mount everything hopefully if i can find spaces under the vehicle where i need them to be, the sides and roof seem to line up with something i can put a bolt in just fine ironically, yet again , things could change as i go we shall see!

 

[JohnL2001]

Little more progress
3/4 mdf, 3/4 oak ply, 2x4 framing started glued and screwed

t nuts front and back (lowes shorted me two so two are missing in the pic, wife went out and got me two more though)

 

[JohnL2001]

 

[seafish]

Looks good and sorry if I missed it, but I sure do hope that you are planning on putting a brace strut or two or three in the middle of that large baffle between the subwoofers at the very least.

 

[JohnL2001]

Looks good and sorry if I missed it, but I sure do hope that you are planning on putting a brace strut or two or three in the middle of that large baffle between the subwoofers at the very least.

yeah you missed it but no harm no foul.

about two posts or so up i explain that.

 

[JohnL2001]

Looks good and sorry if I missed it, but I sure do hope that you are planning on putting a brace strut or two or three in the middle of that large baffle between the subwoofers at the very least.

and the center post thats going in will be a little longer than needed so as to push up on the roofline since i think this will solidify everything a little better......with rubber between the post and van roof of course.

 

[JohnL2001]

 

[JohnL2001]

 

[JohnL2001]

 

[JohnL2001]

This baffle had to be driven in with one person pulling up with all they had on a 4 ft pry bar and two people with one sledge hammer each banging away on it......the only way we got it started on its way in is I personally had to lay down and kick as hard as I could with someone holding me in place.....

if There is a leak when I’m finished I’m not even going to sweat it at this point ! (we all know thats BS) But the truth is i SERIOUSLY doubt there will be an air leak once the sides are finished up (hopefully before i hit the sack tonight but im not sure because those will be some intracate cuts and the templates i had made may not work so well since we could never get this thing fully level.....its about an 1/8" out of level top to bottom but we had to quit on it and ill just live with it.

The good news is the roof of the van sounds pretty damn solid now , mostly from all of the pressure being appliied by the shoehorned in baffle and deadener...plus ive got a few more boxes of deadener to put on it and more of the rubber to put in places that i think may give me rattles such as the framing members of the roof that could break loose from their spray foam insulation from the factory. and im sure there will be many rattles to track down other than that....soon hopefully.

Would probably help if i got up and went back outside if i want it done, but its very humid here and im on break!

IF THIS DOES NOT SOUND GOOD..............I may well drive the van off a cliff lol. put too much work into this!

 

[JohnL2001]

Had to cut out for the night but got started enclosing the sides. I’m doing that before I frame in.

also found why I was out of level by an 1/8” and will be fixing it as soon as I’m up for another round of hammer swinging.
It’s ok that I didn’t get to finish it this weekend, it gives me time to consider some ideas and get used to the drastic change in sound
and the ac being super strong nstead of struggling to cool the huge van area lol imagine a refrigeration tech that doesn’t bother to fix his own ac…. I never have time. But , at least now there is a 90 percent less chance that something is going to slide forward in the cabin and hit me upside the head. Silver linings! clean up was once again brutal this weekend of the build... at 10pm knowing you have to be up at around 6 in the morning and you still need to clean your yard up, load your van up with tools and put all the tools you had out , back up, into three different buildings in the dark (larger sized yard, we live rural, things are cheapish)

yet here i am, on the build log...

 

[JohnL2001]

Wanted to leave myself a note or two

I think i may build my shelving in this fan so as to create a sort of "box" that takes up just the right amount of space so the subs see say for instance EXACTLY 72 cubic ft of air space if thats what they so desire....cant remember right now what that number is but that doesnt matter ATM.

Also, the baffle is going to probably be 5" + thick with a wicked design, more on that later when its done. What you see here so far is only a skeleton of a baffle in my mind.

Also leave myself another note because i am already forgetful at 43, it looks as though i could scoot the baffle back when i go in to realign it which i have to do anyway, and use U bolts to attach it to the old mid row seat hold downs instead of nut serts through the floor which would solve my problem of trying to put a bolt every 6-8"inches with a nut under the vehicle .....with things like...you know, an exhaust, a driveline, subframe rails etc in the way. Its an idea anyway. OF COURSE, this will be quite the chore since the bottom 2x4s are wood glued to each other and one is glued to the baffle maybe both cant remember right now.....chit

I think my problem is, i can never leave well enough alone. In fact i know its my problem.

Would explain the random projects i start around the house and never finish.

 

[JohnL2001]

ok, next day
i had a light work day so i spent a few minutes covering the sides quickly with boards in a non permanent fashion ( still had some leaks on the sides no doubt)

at 20-30 HZ its a complete wind machine, but it doesnt sound very good to me for some reason. Keep in mind i was just testing the theory and had no dsp or had done no tuning which may make all the difference in the world.

At the very least my plan is already a success because i only wanted my subs play 50hz and below in the first place, and im sure they will play that with eq and ACTUALLY finishing my baffle.

I literally had no test time by the time i was done it was 9pm and i had to consider neighbors lol so who knows what this thing can really do i may be way off base by my assumptions.

OH YEAH THEY WERE BEING POWERED BY A 200 WATT MONOBLOCK LOL AND IT IS VERY CLOSE TO TEARING NOTEBOOK PAPER UP IF YOU PUT IT IN THE WINDOW AT 20HZ. that being said, and thats cool and all, but i may make some changes. im assuming the lack of any music ( no tweeters,mid range, or mid bass installed) has me a bit disappointed and not so much the subs.

Do they pound? absolutely but at this point anything above 30-40 hz seems like its not enjoyable i dunno what it is yet but ill get it right.

 

[SQ_Bronco]

Wow, you’re making a ton of progress! Looks great.

 

[BP1Fanatic]

I'm digging the SPL+SQ vibe!

 

[Forddenial]

If you decide to, you should be able to use drywall butterfly fasteners with a 1 1/2 - 2"OD washer behind the bolt head to hold up the horse mats for deadening.
You might have to add more ribs to the inside roof so you can maintain a good support for the mat, but those should work

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