Jump to content
SME

(4) Sealed 21": Funk Audio UH-21v1

Recommended Posts

lilmike    36

Apologies for such a lousy pic. That's actually the paint. It's a lovely brown...

 

I'll take a closer image of the finish and try to catch the texture.

Share this post


Link to post
Share on other sites
SME    211

Apologies for such a lousy pic. That's actually the paint. It's a lovely brown...

 

I'll take a closer image of the finish and try to catch the texture.

 

Haha.  I was afraid of that.  I don't find the brown to be so lovely.

 

Work continues on dado routing.  I'm hoping to be gluing stuff together by the middle of the week.  I also should be getting the Duratex today and will experiment and see what I can come up with.

Share this post


Link to post
Share on other sites
lilmike    36

LOL...

 

It's the only color (other than black) that I had out in the shop. I agree, the color is not all that lovely, but it is better looking than raw plywood. SWMBO nixed the black, so it was the lovely brown.

 

The undercoating gun worked really well. Mine came with the kit I bedlined my Jeep with, but the same thing is ~$15 on Amazon. 

 

I'll be spraying all my non-veneered cabinets this way, at least until I find a better approach.

Share this post


Link to post
Share on other sites
SME    211

I have made a lot of progress.  I just have a bunch of little steps to do before I can glue these together and start finishing.  I hope to get there within the next few days.  I'll try to post some pictures soon.

  • Like 1

Share this post


Link to post
Share on other sites
SME    211

I uploaded some pictures of the cabinet pieces and one of the partially glued cabinets.  I finished partially gluing the other cabinet today.  The gluing was a bit of a pain.  Some of the Dado joints were not as tight as I would have liked, and I used a lot of epoxy with filler to try to fill the space.  I used what seemed like *a lot*, and it still didn't squeeze out as much as I wanted it to.  I'm thinking I'll want to do some kind of secondary treatment to prevent leaks.

 

Once the current glue is dry, I will cut and install a total of 24 braces per cabinet between the baffles and major interior braces.  Then I need to round-over, sand, and finish.  If my experiments with the Duratex don't work out, I may just go for straight black paint.  I can treat the inside of the cabinets and wire them while I wait for the Duratex to cure.

 

I'm very glad I installed the threaded inserts for the feet before the gluing.  I also am glad I bought extra feet.  They are very helpful for tipping the heavy cabinets onto.  I will eventually install the extra feet onto one or both sides of a board to give me something to tip the subs onto when installing the drivers.

 

Oh yeah, the order for my trim rings is in now.  I don't know when I'll get them, but I'm thinking 4 weeks as a rough guess.  I just hope I get them by the time my finishing is done and I'm ready to install the drivers, so I can install them once and be done with it.  I'm even planning to wire the Speakon's so that I can change the coil configuration without yanking any drivers.

 

These things are big, but at least they are manageable.  People on these boards are crazy with their 350 lb+ subs.  :)

Share this post


Link to post
Share on other sites
SME    211

I finished the rest of the bracing today.  Next is round-overs and then finishing.  I'll try to get up more pictures soon.

Share this post


Link to post
Share on other sites
SME    211

I added a picture of the inside with the rest of the braces glued in.  The extra braces stiffened up the baffles a lot.  Going by ear on the "knock test" the fundamental resonance of the side panels sounds like it's around 320-350 Hz.  I think that ought to work OK for a sub.  The baffles definitely ring higher.  :)

 

I tested out some Duratex on a big scrap using this roller (bought from Guiry's).  This is a single coat where I was just screwing around.  Note that I artificially enhanced the sharpness slightly to emphasize the texture:

 

post-1549-0-57205500-1488178842_thumb.jpg

 

The bad news is that I will need to practice a lot to get a consistent appearance.  I joked with my wife that it looks like a black leather sofa swatch.  The good news is that a few spots I covered actually look pretty good.  So if I can figure out what I was doing there, I may be able to get what I want.  I also want to try a technique I've seen others suggest, which is to smooth the texture using a separate dry roller.

 

Before I started, I gouged the piece on purpose with a chisel and repaired it with the Durham's wood putty I bought.  I also filled part of a drilled hole in the middle.  So far, it looks like the Duratex covered the repairs well.  I can just barely make out the hole in the middle if I look hard for it and catch it at just the right light.  I hope it will disappear completely with thicker coverage.  I considered bondo but had heard it sometimes didn't play nicely with the Duratex.

Share this post


Link to post
Share on other sites
SME    211

This is attempt / coat #4:

 

post-1549-0-20498300-1488347449_thumb.jpg

 

I'm going over everything lightly with a dry roller after applying the coat.  I really like how the texture looks and feels.  It's a lot blacker than it looks in the photo.

 

Some issues noted:  The surface has to be very even and smooth or else it shows through.  I'm getting a weird ripple or wave effect from the roller.  It's more subtle than it appears in the picture, but I'd rather not have it in the final product.  It may have to do with uneven loading of the wet roller, which may then deposit differing amounts of material in waves.  It sands out, but the appearance is a bit more distinctive (and blacker) if I don't sand afterwards.

Share this post


Link to post
Share on other sites
Ricci    652

Don't get me wrong finishing with Duratex is a fascinating subject, but have you actually hooked up these awesome drivers in cabs and listened to them yet?!!!!

  • Like 1

Share this post


Link to post
Share on other sites
Infrasonic    153

Don't get me wrong finishing with Duratex is a fascinating subject, but have you actually hooked up these awesome drivers in cabs and listened to them yet?!!!!

 

Seriously.

Share this post


Link to post
Share on other sites
SME    211

Don't get me wrong finishing with Duratex is a fascinating subject, but have you actually hooked up these awesome drivers in cabs and listened to them yet?!!!!

 

Seriously.

 

My new mains are still unfinished.  That's what happens when I plug in and listen to speakers before they have been finished.  Seriously.  :)

 

These subs will be installed under my left and right mains, and installing the trim rings will require tipping the cabinets driver-side-up.  I'd rather not go through the process of buttoning them up more than once.

 

Thankfully, I'm very close, and my trim rings will hopefully ship soon, so I can get these running within a couple weeks maybe.

  • Like 1

Share this post


Link to post
Share on other sites
SME    211

I did a fifth coat on my test sample, and I'm very happy with the appearance.  The wavy marks are gone.

 

I also patched the cracks and other flaws in the cabinets today.  Tomorrow I'll sand and patch where I missed today.  Then they get the Duratex.

Share this post


Link to post
Share on other sites
SME    211

I finished patching and sanding the cabinets and uploaded a picture.  I'll be starting Duratex coating hopefully tomorrow.

 

It looks like the shop doing my trim rings is a bit behind.  I don't know exactly when I'll get them yet.  I probably won't wait for them before putting these into service.  I *will* wait until the Duratex has cured before moving them to avoid damaging the finish by setting speakers on top of them too soon.  So it's pretty much down to waiting on the Duratex to cure before I can get these running.  I also need to find someone to help me move them upstairs.

Share this post


Link to post
Share on other sites
Kyle    62

Don't get me wrong finishing with Duratex is a fascinating subject, but have you actually hooked up these awesome drivers in cabs and listened to them yet?!!!!

 

Dido

Share this post


Link to post
Share on other sites
SME    211

Am debating one more coat:

 

post-1549-0-71491700-1489221843_thumb.jpg

 

The roller lines are faintly visible at some angles of the light, but otherwise I really like the result.  After this, I need to do the other cabinet, and then finish the last few things.  I still don't know whether I'll wait for trim rings, but I don't really have space for them in the room without putting them under my speakers.  And every time I move the speakers, I need to re-position them optimally for the seating area.

Share this post


Link to post
Share on other sites
SME    211

Late last week, I finished with the Duratex on the cabinets.  I couldn't get rid of the roller lines completely, but they are subtle when they are visible at all.  They get thumbs up from my wife.

 

To give them plenty of time to cure, I am going to wait for the trim rings which should hopefully ship at the end of this week.  Once I get them, I'll need to wait for the following weekend to get the help I need.  So hopefully I'll get them running the weekend after next.  I hope there's some ULF in "Rogue One".

Share this post


Link to post
Share on other sites
SME    211

I'm still waiting for the trim rings.  They should ship any day now.  Then I'll need to arrange for help from my friend.

 

In the meantime, I've been working on optimizing the UHF response of my front stage speakers.  I'm running my DNA-360s all the way to 20 kHz now.  Wow!  The detail is truly incredible.  I've owned other speakers and headphones that extend to 20 kHz, but these SEOS horns sound very different.  The sound at the top is somehow much more audible than with other speakers I'm familiar with.  Maybe the wide dispersion is a lot of the reason for the appeal of ribbon tweeters?

 

It also surprises me just how much audible content there is in the 18-20 kHz range, even though I can't hear sine waves much beyond 17 kHz.  It seems that the thresholds change dramatically in the presence of simultaneous lower frequency content.

Share this post


Link to post
Share on other sites
Infrasonic    153

Nice. What were you doing with them before?

 

I remember for a while (same DNA360+SEOS12 combo) I was ignoring the measurements from my Omnimic above like 13khz or something, thinking it wasn't accurately measuring up that high. Idk. Then I started getting a bit more aggressive with the shelving filters and PRESTO! the clarity of these can be pretty amazing.

Share this post


Link to post
Share on other sites
SME    211

Up until now, the UHF has been a bit of a nuisance region.  I never seemed to be able to calibrate it so I could actually hear most content there and not have it sound irritating with a lot of stuff.  A flat target doesn't seem to work well with a lot of content, which may have to do with the fact that a roll-off of some kind is present on many (most?) pro monitors.  Another issue is that in the break-up region between 15-18 kHz or so, the dispersion diverges a lot from the normal horizontal horn pattern, so there is the question of which measurement(s) should be flat.

 

Previously, I was running to 18 kHz and then using an adjustable roll-off to try to accommodate different material.  With this approach, I could avoid irritating sounds most of the time, but I was throwing away a lot of detail for most content.  What persuaded me to revisit my configuration is the fact that some content just couldn't be cleaned up using the roll-off curve.  Beyond some point, increasing the amount of roll-off actually seemed to make harshness worse.

 

I revised the roll-off curve to approximate in-air absorption effects to within 0.1 dB or so all the way to 20 kHz.  In retrospect, the old curve was nowhere near precise enough.  With the new curve, it was obvious that my baseline response needed more work because I could no longer quell unpleasant sounds using more roll-off.  It took me a couple weeks of listening, measuring, and iterating on EQ to get the job done.  For a while, I felt like I might go crazy from spending hours at a time being hyper-attentive to treble.  It seems that anything less than perfect response can cause unpleasant ear sensations.

 

I still find the adjustable roll-off to be useful, even though it doesn't change the sound much.  I know the measurements I've seen of Genelec monitors reveals them to be -10 dB @ 20 kHz.  OTOH, JBL's stuff typically runs flat all the way to the top.

 

**********************

 

In other news, my trim rings shipped last Friday.  I'm scrambling now to get the last steps done on the sub cabinets so that I can get the drivers installed ASAP after the trim rings arrive.  I'm hoping to get them running this coming weekend, but I will be busy doing family stuff on Saturday.  At least they decided not to come over here, so I don't have to worry about being only half-finished when Saturday rolls around.

Share this post


Link to post
Share on other sites
SME    211

I finally have the trim rings.  The cabinets are all done.  I'm down to trimming rubber surround out of the screw holes and building a couple cables and splitter adapters.  I have a friend coming over tomorrow afternoon to help me move the cabinets upstairs.  Depending on how things go, I may get some good listening in tomorrow, but it's more likely I won't get a thorough audition of their capabilities until Sunday.

 

I still don't have 240V, so I won't be able to push them to their limit, but I'll be able to get close.  These will blow away the subs they are replacing.

  • Like 2

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×