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First Summer Project - finally a decision on drivers.
So the other day I glued up a couple PE flat packs, and then dove into the stash to see what I could put together cheap and effective.
I modeled several 6.5" class drivers in the tower, and surprisingly the generic Kevlar driver I demo'd at IowaDIY in 2019 modeled the best. Other candidates were the Dynavox 6.5" honeycomb, the Max Fidelity 6.5", and a Rival.
This will be a 3-way, midrange will be the cheap HiVi 2" dome, tweeter will be that Dayton waveguide thing. The woofer and tweeter used to live together in the design I brought to Iowa.
Here is what I mean about how it models, most alignment details are in the screenshots:
Modeled extension:
Modeled excursion at 10 watts:
Modeled SPL at 10 watts:
Modeled vent velocity at 10 watts:
Driver parameters:
I will machine the baffles today, and finish the glue up.
So the purpose of this design, in addition to getting rid of shit, is to gift these to a couple we are friends with.
Here is what a slight EBS looks like:
I beat the living shit out of these cheap woofers, and was impressed with how much of a asskicking they could take. I have no compunction about driving them down that low.
Should be a fun, quick, and relatively straightforward project to get done.
Comments
Driver layout, HiVi was nice enough to include a bit of foam that is the diameter of the driver.
About $140 all in on drivers, not too bad.
This is the in-box measurements of the aforementioned 2-way. I am hoping to be able to massage things into a 900/3000 crossover points but I'll let the drivers talk to me.
Totally shocked that that dude modeled better than the Rival. Nothing shabby at all about the 1st alignment with an F3 of 35 Hz!
I think I'd go with a 2.5" diameter x 4.375" long port to reduce the port velocity. You're gonna have some wild Z offsets with the waveguided tweeter vs. mid dome sitting quite proud of the baffle.
Yeah, the offsets should prove interesting!
I don't have any other ports sitting around and I am determined to spend as little as possible on my hobby this year! Consume what I already have - what I have is a bunch of the 2" PP kits I bought when they were on sale because you know, on sale.
Actually, found these rummaging around my hoard. Slight taper from ~2.5" to ~2.25", but should be somewhat better. I'll hack a bit of length off.
Plus the dimples are kind of cool, I guess.
Those dimples reduce the lateral inertia of the blah, blah, blah, blah, blah....= Marketing Speak.
OK - they do look pretty cool!
Were these the drivers in the speakers that you had smoke coming out of the ports?
Honestly, I'm not sure if these were smoking or not.
I just remember a small two way that played way louder that it had a right to, and a mention of smoke coming from the port.
Sounds like one of mine lol. I still have assembled crossovers for that design, k should look at the resistors. Drivers seem fine. Listened many times after that Iowa.
These will be close to the wall, so I am front porting them. Not my preferred, but should work well enough. I might port out the bottom, too - I have a set of outrigger spikes I plan on attaching to these.
Will machine baffles, trim, fill, etc tomorrow.
Just because I love playing with old school AutoCAD:
I bought, through college at the time, a license of AutoCAD 2002. It has run flawlessly on Win98 (I had an old copy of LSPCad that seemed to prefer Win98), Win2K (the OS I used in that round of college), WinXP home and pro, Win7, and Win10. Not a single issue under any of those operating systems. Incredible.
I just opened an older solids model I did, and it still works just fine, as well:
That was a labor of love (and alcohol combined with boredom). Modern software will whip out a technically accurate threaded part with almost no work - this was a combination of LISP routines and tedious solid modeling. It is technically accurate, a 1-/4-24 threaded bolt.
Anyways, time to go do my Saturday errands and wait for glue to dry. Wife and I are going to host a friend tonight, the three of us are going to watch that Kong v Godzilla movie.
Let us know how you liked that movie.
it was ok. Lots of action, monsters.
Butchered the mid-range rebate, oh well. Looking neat otherwise.
A butchered rebate is 10x better than any movie I've watched. Looking good dude🤘🏼
I got the tweeter rebate pretty good:
And the woofer (except where I jumped a bit):
The gasket came off, so I set the flush mount depth to the woofer frame. I have some ideas on how to trim it out...
I cut the mid-range rebate too small and (haha) attempted to free hand repair it. Time for some Bond-O:
Otherwise, coming together nice. Have these, as well:
Yeah, EVERY time I try "just a little" router free handing, it ALWAYS turns into another job for wood putty.
You'd think I'd learn....
I'll touch things up tomorrow.
I put the port at that height to leave room for some stuffing in the bottom of the cabinet. Should be interesting to see where tuning ends up.
I don't think I should have any problems getting a crossover worked up.
I also mowed the lawn and cleaned the garage today, so now it is time for a beer and maybe a nap.
I've bagged a driver with plastic-sack or bread-sack before, sanded rim for adhesion, and applied epoxy to the perimeter. Set bagged driver in place, and wait for it to dry. Sand and finish!
InDIYana Event Website
I usually use some painters tape around the edge of the driver and press it into the gaps. Should be able to get around to it today.
I'm perfect and never fuck up.
Well, that approach is not going to work. Alternatively, I am going to soak some felt in Tite-Bond and run it around the edge of the driver rebate, then stick the taped off midrange in there to form it.
I have done this before, if you use thick enough felt it will compress and form fit. After it cures, I will smooth it out and apply a thin coat of wood filler over the top and sand it smooth.
Or, I may just accept this is a super budget design and deal with the uglies.
If it were me, I'd slop a bunch of bondo in that hole, sand or plane it flush to the baffle. Screw in a board from behind and re-route the counterbore.
The board screwed in from behind worked well for me some years back when I cut holes too small.
You can also fill in the messed up part and make a template to use a top bearing router bit with. Use some double stick tape to hold it in place. I make all my rebates that way.
Ron
That felt trick sounds neat. I've done the option dcibel suggested, that'd work fine. Either way, def fix it, that shit would drive me nuts.
One other option is to wrap the outside of the driver with masking tape, but sticky side out, and then put body filler around to hole and press the driver into to wet body filler. The driver will be in there snug and a bit resistant to removal, but it will come out if you flip the box over and give it a smack.