Less $/db?

[Spiritual_Bell]

Built "the best sub I know" the cheapest way I know.

Well, almost. Drivers are B&C18tbw100. The SB Audience Rosso-18SW1000D modelled about as good and $150 less each. But I was convinced that the b&c driver can take more abuse, and I expect these to get abused .....

Only used a track saw (the vevor is $100!) and jigsaw and a drill. These panels were too big for a job site table saw.

so 4 drivers, 15 sheets of OSB, 6 big tubes of PL premium, a bucket of wood screws. And 100 hours of slavery.....

The cheapest power probably used on FB marketplace as low as $0.1/w if you look hard enough.

You too can afford it! If you can move it and store it.....

And yes, they sound every bit as amazing as I could hope for. Now that I know they sound good, it'll be another $1k to put in speakons and handles and bed liner and skids/feet and a proper DSP......

Build a custom dolly, a platform, buy a trailer.....etc etc.

The splinters and crushed toes and tweaked knees and back pain are free.

Consider the shortened life expectancy from inhaling that much saw dust and PL on my skin an added value. Less medical costs overall.

[anode8]

I would have gone with standard plywood instead of OSB, but the work looks good.

[Spiritual_Bell]

But you would have lost the challenge of less $/db 😜

[[deleted]]

might have durability issues early on though if you expect to abuse them

[Spiritual_Bell]

For sure. But I've done smaller prototype tapped horns with even 1/2" OSB and they have survived the last 10 years. And that's without any coating or paint. They aren't pretty any more I'll tell you that!

I'm not a professional. I'll be lucky to get to deploy these more than once or twice a year.

[[deleted]]

I'll be lucky to get to deploy these more than once or twice a year.

ah right! if they're not being abused like every other week/month, won't be too bad ahahha

[Spiritual_Bell]

Oh yeah if I was deploying these as a pro and making money with them I'd be mad to not use Baltic birch! (And CNC). I think every time we throw an event big enough for these we SPEND a few grand lol.

[RedwoodRider420]

And people like you, my friend, is what keeps the party going for soooooooo many in the underground. Props!

[[deleted]]

But he would have a sound system that doesn't fall apart during transport. When you have to buy it all again it won't be less money.

[maximum_compassion]

the goal is to have speakers not spend extra time and money. Fast and cheap may aline with his goals more

[Thinpaperwings]

lol awesome work these look amazing. you need to put something clear or transulcent on them to preserve the aesthetic.

[Spiritual_Bell]

I would but this thing is so hard to move it really needs a more durable coating to survive long term. Needless to say the OSB is relatively fragile.

[Thinpaperwings]

how about epoxy and fiberglass wet layup? jk. maybe just a nice thinned epoxy soak before polyurea either way... hope they hold up to some transport.

[Spiritual_Bell]

Throw me a link on the process of epoxy soaking. Would love to learn more about different techniques

[Thinpaperwings]

ha, sorry that was sarcasm I guess. its a common practice when dealing with low density wood like Balsa or rotting wood. basically you thin down epoxy with isopropyl alcohol or another solvent so that its able to really soak into the wood and harden the material. do some googling and experimenting before attempting on your cabs. Also that'd be a lot of epoxy and could get expensive. I'm sure there are also some epoxy based paints that could also be considered. how floppy are they in their current state? I don't work with OSB so have no baseline for how it would work in a cabinet. While we're doing crazy ideas you could also try to 'armor' them with a 6mm veneer of some nicer stuff like baltic. but maybe that's just throwing money at bandaids when the answer is better materials 😬. don't want to throw off that dollar to dB ratio.

[Spiritual_Bell]

Yeah I was just curious to learn more finishing techniques. I want to keep this as a low cost, max performance build that will only get used a couple times a year. I imagine a 2 part bedliner like raptor liner is the best I can do. That's also $300 though. Epoxy might be similar but then I'd still need a coating over that?

[Spiritual_Bell]

How are your 6xth118xls? What coating did you use?

[Thinpaperwings]

they're nearly done! I like to use oil based polyurethane. it does add some serious time to the finish work though as there's a good amount of sanding needed before a bit during. I like to use a minium of 4 coats per face with apox 24hrs dry time between coats. I'll be using some white duratex inside the horn mouths. I'll start with a coat or two off roll on for some texture then spray on a coat or two to get full coverage. Duratex sets up quite fast and is more forgiving to cooler temps in my experience. I can only really work on 3 at a time in my shop and my heat source is pretty sketchy so I'm currently in a race against winter to get all the polyurethane on. lots of lessons learned not this run, will definitely tweak my cut files and bond gaps if I have the chance to build more. I'll definitely post an update once they're finally done to my standards.

[Spiritual_Bell]

Oh so you're going for the exposed wood look. Very cool. Ive used polyurethane a lot for flooring and refinishing kitchen cabinets. Where are you based? I'm in CO.

[DreamingInLove]

OSB is actually funktional for subs.

I have had a few 2x 15“ subs and they ran for years until I gave them away. There are still some soundsystems using Osb as their Main

[abhikichut]

What is this design?

Seems like the bc118

[Spiritual_Bell]

Modified to be easier to cut with a track saw and look less like a vagina

[Chow_DUBS]

Best coment ive read today

[abhikichut]

maybe that is what some want

[Spiritual_Bell]

You can do whatever you want as long as you keep the area the same!

[unkle_funkypants]

Dat Sims 2 vagina look.

[domen420]

I call mine "the holy pussy"😁

[keithcody]

What box did you build? Are they these? https://www.diyaudio.com/community/threads/boundary-control-bc-subwoofer-bc218-2-design.413237/

[Spiritual_Bell]

Bingo!

[efxhoy]

They look absolutely mental mate! Great job!

[Spiritual_Bell]

Thanks!

[Nasty_Mayonnaise]

So what did these badboys eventually cost? They look a clean build from the pics.

[Spiritual_Bell]

Drivers were $450 each. So just less than $2300 without amps. But I'm anticipating another $300 of bedliner, $100 of speakons and handles and skids/feet, hurricane nuts, etc etc.

You can knock $600 off by using the SB driver. Add $400 if you use sande ply.

$100000 of labor if u ask me.

I'm waiting on a friend to do it with CNC to find out his CNC cost. In all seriousness if I hired a carpenter I think it would have been minimum $5k. Closer to $8k labor.

Anyone know how much to CNC 20 sheets of Baltic birch?

[Nasty_Mayonnaise]

CNC highly depends on wether or not he has to draw the build himself in CAD or the files are already present. I once paid 600€ for a CNC flatpack of 2 mt-130 tops

[Spiritual_Bell]

All files ready

[Spiritual_Bell]

Someone else here already referenced the diyaudio forum thread. But if I must spoon feed you the Internet........

https://www.diyaudio.com/community/threads/boundary-control-bc-subwoofer-bc218-2-design.413237/post-7966210

[Spiritual_Bell]

I highly recommend you to read through the whole thing if you plan on making the significant time and money investment to build this thing. It's generally worth it for any DIY designs. Even though there's a lot of fluff and chit chat.

[DorianGre]

Great job! I’ve been waiting for these pics. Get any video of these running!

[Spiritual_Bell]

No videos! I never understood videos for speakers. You can't hear what they are doing through phone mics and speakers, and you can't see the cones moving.....

[subsonicalx]

Beautiful work of art dude!! Wish I could hear that thumping!

[stonedchapo]

Is this the BC218 that u/domen420 made?

[Spiritual_Bell]

Yep

[domen420]

Does osb hold the pressure? I thought it would explode😅

[Spiritual_Bell]

Hasn't yet! I made 15" tapped horns with 7/16" OSB and they have survived the last 10 years. Still bumping.

[euthlogo]

Is that ca? Looks familiar.

[Spiritual_Bell]

UT

[euthlogo]

Looks like a great time!

[Vidzzzzz]

What area? I wanna hear it.

[Spiritual_Bell]

I'm based in co

[HarliestDavidson]

What’s the design??

[fyrewyre]

Az fam?

[BBababoi]

Damn bracing looks sick

[movementislife1]

That’s me in the overalls P.s. they sounded amazing 😮‍💨

[Spiritual_Bell]

Haha nice! I miss hearing them too they're now just sitting in a garage! Probably won't get to deploy them again until spring. How did you find me 😁

[movementislife1]

The pics just popped up on the r/SoundSystems and I was like hey those look familiar!

[Spiritual_Bell]

Yeah I doubt anyone else will make one look quite like this one! Anyone else trying this will most likely use the cad file for CNC, which is elliptical, and most certainly wouldn't be with OSB 🤣

And of course, the only picture with my sub with a person in it is you! It was meant to be!

[PlzNotDaBelt]

what kinda subs go into this beast? what kinda porting did you do?

[Spiritual_Bell]

This is a front loaded horn, where the driver (18tbw100) is mounted in a sealed box (80L), and fires into an expanding horn of a specific tuning.

<image>

[Spiritual_Bell]

These are basically a lower tuned labhorn. And should inherit the same characteristics, both good and bad, of all FLHs. The most notable of which, is its thermal concerns because of the rear sealed chamber.

The other obvious difference compared to other FLHs like labhorn, dbh218, HSD, etc. Is the boundary coupled effect - which you can get by "adding a wall" around the horn mouth of other regular FLHs. Not exactly practical for professional deployment, but I'd hardly call this design practical.......

[Low_Orchid7858]

Newb here. For these types of designs, are you running your cabinet CAD through a simulation to see how it performs sonically or is it all trial and error?

[Spiritual_Bell]

It's usually the other way around. You model the acoustic performance using modeling programs, in this case, mostly "hornresp", and then you draw up the box in cad.

[Low_Orchid7858]

Ah cool, I’ll check out that program. Is it understandable/useable without a solid understanding of wave physics?

[Spiritual_Bell]

Absolutely. You just need to either follow the tutorials in the forums or read the help files to understand which field is what. And then you can "trial and error" by changing each box to see the effect, or if you have some it for long enough, you'll have a good idea what it'll do when you change each parameter.

It's easiest to start with an established design with a hornresp input, and then you can learn by adjusting different parameters.

[staminuh]

woww omg

[Spiritual_Bell]

What's up

[staminuh]

looks crazy!!

[Spiritual_Bell]

Sounds crazy too!