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Aaron's THT build.

post #1 of 25
Thread Starter 
Hey all, with the sale on the dvc and bash amp over at PE, I jumped in to a THT build. I'm planning on staining it to match the wood trim on my tv stand, but if that turns out bad, I can always prime and paint it black. I'm sure i'll have lots of questions along the way.

Unfortunately, I'm starting off with a materials question:

I bought 1/2" Baltic birch for the outsides, but I bought a sheet of 1/2" arauco as well, to handle interior panels, bracing, and whatnot. At least, they told me it was arauco...
Here's a snapshot of the bill:


And here is what I noticed when I unloaded the truck today:


A shot of the edge:



Sooooo...
Is this pretty much the same thing, or should I pitch a fit tomorrow?

Thanks,
Aaron
post #2 of 25
Same thing. 1/2" ply is never exactly 1/2" and the arauco always has those voids in it.
post #3 of 25
Thread Starter 
Ok. I wasn't worried about the 15/32" part. I was mostly concerned with the company name stamped at the top (the left in the photo... I forgot to rotate it) I googled "Pacific Wood Laminates", and they're a mill based out of Brookings, OR. I thought Arauco was based in South America?
Thanks,
Aaron
post #4 of 25
That is not Arauco--a product of Chile--I don't care what the receipt says. I wouldn't use it. Too many voids. But, I would use Arauco.
post #5 of 25
Quote:
Originally Posted by PassingInterest View Post

That is not Arauco--a product of Chile--I don't care what the receipt says. I wouldn't use it. Too many voids. But, I would use Arauco.
+1. Arauco is a brand name for radiata pine, and Arauco does not come from Oregon. It doesn't even look like Arauco; it does look like a North American species, spruce, pine or fir, that does come from Oregon.
post #6 of 25
Thread Starter 
Ok. I'll call the lumber company in the morning. It could be a mistake by the guys that pulled the stock.

Thanks
post #7 of 25
Thread Starter 
Well, evidently they switched suppliers, and didn't update their computer. One of the guys in their warehouse suggested another lumber company, and when I called them, they were a bit more helpful. Unfortunately, they have no more 1/2" Arauco. He said that they routinely field calls from distrubutors 2-3 states away trying to find some, which leads me to belive I won't be finding any around here. I'll try calling some others, but I think I'd better move forward with a contingency plan.

Originally I was planning on using the BB for any visible pieces (the exterior and mouth braces) and a box for the plate amp, Then, I'd use whatever BB I had left to do the rest of the internal panels, substituting Arauco when I ran out. Other braces and jigs from the plans would have come from the leftovers.

Now that I can't get Arauco, I'm going to have to take another look at my cutlist. If I can get all of the panels and mouth brace done with the BB on hand, I might as well save some money on the other braces. What's the cheapest grade plywood acceptable for the braces? Also, can the octagonal driver spacer be made of the cheap stuff?

Thanks,
Aaron
post #8 of 25
You should post your questions on my forum. Thanks.
post #9 of 25
Bill's build plans allow for the most efficient use of materials imaginable, so you might not even need additional sheets.

But if you do, I'd get some Russian Birch from McCoy's Lumber to use for all the internal parts that won't show. I found a McCoy's in Okmulgee, about 29 miles from Tulsa. $26.99/5x5 sheet, 1/2". This is Baltic Birch, but a lower grade, so it has football patches and is considered a good shop-grade plywood. Other lumber stores may carry it as well. So, you might find some closer to home.

Edit: I forgot the link for the Russian Birch at McCoy's Lumber.
Edited by PassingInterest - 12/7/12 at 11:52am
post #10 of 25
Thread Starter 
That sounds like a good plan. Okmulgee isn't too far away, as i'm on the south side of Tulsa.
Thanks!!!
Aaron
post #11 of 25
Thread Starter 
Well,
A slight delay. I spent a bunch of time yesterday messing with my track saw kit, before finally realizing it had been pre-drilled wrong. The manufacturer is replacing the part, but I wasted a lot of time feeling like an idiot trying to put it together.
Company Christmas party today, so I probably won't make much progress.
Grrrr
post #12 of 25
Thread Starter 
Okay, more than slight delay. Work/Life/Holidays... you get the idea...

Anyway, the panels are all cut, I just need to cut the braces. I tested out my router/Jasper combo, and cut the hole in the baffle doubler. (Pics to come later)

Then, I pulled the driver and amp out of the box, and set it up for driver break-in. Hopefully one someone can tell me if I did something wrong.

1) I downloaded a 20Hz test tone and transferred it to my ipod.
2) Set ipod to repeat track indefinitely.
3) Connect amp (bash 300) to iPod, and throw a multimeter on the speaker leads. \
4) Adjust controls until it reads 10VAC.
5) turn amp off and connect leads to speaker (both coils in parallel)
6) turn system back on
7) immediately turn system back off due to the hideous clanking sound
8) spend a couple of minutes convincing wife that I'm not going to burn the house down
9) turn the volume knob all the way down, and re-energize system
10) Turn knob slowly back up until an audible version of the clanking is heard. (It's a similar sound, just not so alarming in volume.)
11) Turn the system off, and ask for advice on AVSforum.

Now, the driver was sitting on its back on the carpet during this test. I'm thinking that I might want to cut the hole in the baffle, glue the doubler on, and go through the driver mounting procedure, then repeat the procedure with the driver off of the ground.

But, is it possible I have a bad driver, or did I do something wrong?

Thanks,
Aaron
post #13 of 25
Great to see more folks building THTS! I'm still enjoying mine. It's the last sub I will ever build.

FWIW I used a sign-sweep between 10hz to 100hz and the voltage peeked at around 16 volts. I never heard any clacking at these levels but any more I surely induce the voice coil banging the back plate.

I suspect that if I had played just 20hz and had it up to 10volts at that freq I would have heard some clanking noises too.

https://www.youtube.com/watch?v=GschL-5QHas
post #14 of 25
With 10v input at 20Hz excursion of the unmounted driver is 5mm. When breaking in it's best to gradually increase the voltage from zero.
post #15 of 25
Thread Starter 
Thanks guys, I'll do it again, starting lower, and I'll slowly take the voltage up.
Just to be sure, there's no problem with is sitting flat on the floor on the back of the motor frame?
Thanks,
Aaron
post #16 of 25
Connect it all up. Start with volume low. Turn on. Slowly turn volume up until you reach the desired voltage level. You can have both the driver and volt meter connected at the same time.
post #17 of 25
Thread Starter 
Tried again. The noise starts at 1V. By the time I hit 1.5VAC, it was as loud as I dared to push it. Is this normal?
This time, the multimeter is connected directly to the coils during the test, so I'm not just measuring open circuit voltage.

Thanks,
Aaron
post #18 of 25
That does not sound right to me.
post #19 of 25
Quote:
Originally Posted by abmorse1 View Post

Tried again. The noise starts at 1V. By the time I hit 1.5VAC, it was as loud as I dared to push it. Is this normal?
This time, the multimeter is connected directly to the coils during the test, so I'm not just measuring open circuit voltage.

Thanks,
Aaron

Ok I have something for you to check, this has happened to 3 of my dayton's like yours. The spider is glues on to a metal ring that attaches to the basket assembly, it's about 1-1/2 - 2 inches high. For some reason, the glue they used on them sucks balls and the plate actually comes loose from the frame and will do exactly what yours is doing. As you turn it up, the spider will make the metal ring smack against the basket. So turn the sub on to where is makes a bit of noise and grab the metal piece the spider is attached to and hold it down, you'll know right away if the noise stops. If thats all it is, a bead of some epoxy can easily fix it up. I have a enclosed a pic. You can see what I'm talking about and where to look.

post #20 of 25
sounds like a voicecoil way out of alignment.
post #21 of 25
Quote:
Originally Posted by stormwind13 View Post

sounds like a voicecoil way out of alignment.
Could be. It's defective in any event, send it back for a replacement.
post #22 of 25
Quote:
Originally Posted by mynym View Post

Great to see more folks building THTS!


Agreed! Remember when every other build thread on here was a THT of some sort (including yours and mine)? At least this one is frequently updated, but only due to all the problems you've had with it Aaron. Sorry to hear things aren't going as smooth as they should be. But once you get it built, you WON'T be disappointed! I'm curious about your "double wall". Did you add to the internal or external dimensions?


dbl
post #23 of 25
That's definitely not normal.

Let Parts Express know. They'll send you out a new one. FWIW my first DVC had issues as well but Parts Express took care of it promptly.
post #24 of 25
Thread Starter 
Thanks for all the support everyone! I'll contact PE, and hopefully they'll exchange it.
Quote:
Originally Posted by dbldare View Post

At least this one is frequently updated, but only due to all the problems you've had with it Aaron.
dbl

Unfortunately, I looked at the calendar the other day, and realized that my PE (professional engineer) exam is only a month away. I haven't been as diligent in my studying as I should have, so all my free "tinkering and building" time is going to have to be dedicated to studying. I REALLY don't want to take this test twice!

So, the updates (and the progress) will slow down for a month or so.

Quote:
Originally Posted by dbldare View Post

I'm curious about your "double wall". Did you add to the internal or external dimensions?
dbl

I'm not sure what you mean here. I think you're talking about the baffle doubler, which was added into the plans fairly recently, i think. I know older builds like yours and myn's don't have them, but some of the more recent builds do. I believe Bill said that he put it in so that the driver could be mounted with long screws, rather than t-nuts or hurricane nuts. (I'm still planning on mounting with hurricane nuts)

Thanks,
Aaron
post #25 of 25
Thread Starter 
Just a quick update. (I snuck away from the chores for some build time)

PE replaced the DVC, and I got a chance to glue the doubler to the newly routed baffle.

I stopped up the hole in the PL tube with a deck screw, and then rested it on end because it kept oozing. (Wrapped in a shop towel). Does that sound like enough precaution?

Looking forward to the rest of the build!


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