Roboklipsch's DIYSG 4cft ported build using Legacy EF 15" Driver

[derrickdj1]

I've use the screw method and it will work but, getting the screw back can loosen the t-nut.  Maybe put a bit of Gorilla glue on the t-ut and use a washer when screwing in the t-nut.  The washer will keep the screw from going down into the MDF.  Take the screw out after 6 hours to give the Gorilla glue a chance to dry.  I am going to try contact cement in the future for a shorter drying time.

[CECAA850]

Use t-nuts.  After they're set in place, put some glue around the outside of the flanges.  The only time you have to worry about a t-nut coming loose is if you're building a horn loaded sub and don't have access to the back side once the sub is assembled.  In the remote chance you ever have an issue, you can pull the driver and get to the backside without an issue.  When you drill the holes, hold a scrap piece of wood on the backside so you don't blow out the surface of the box on the back side.  Be sure you run your bolts in and out of the threads and they go in and out without resistance prior to installing them.  Be sure you don't get glue on the threads either.

[RoboKlipsch]

CEC so you're saying, put in the t-nuts, and then use a finger and just place a bit of glue on the outside flanges after put into the baffle as opposed to a bit of glue on the flanges and then put them in?  Will do! 

[RoboKlipsch]

The cabinets have been drying since Monday.  After further consideration, I think I owe it to myself and the work put in so far to take it as far as it can go, reasonably.

So with a gloss lacquer base applied, I am going to wet sand apply more lacquer coats as needed, and then polish to a high gloss finish, that way I can see all the mistakes I made in their full glory

 

I took more pictures of the cabinets, I'm not sure they would look much different now from the camera.  But they are much clearer, I think the lacquer has dried and in doing so become much clearer as the chemicals evaporate from the lacquer.  I hope and intend that the extra work won't take more than another week or so, as I'm eager to be done.  But doing it right I feel is important, so I'll go the extra miles.  For now I'm not putting on feet.  Until I decide what I may really want, they can rest comfortably on the carpet.  

[derrickdj1]

Building the sub was easy.  Doing a real nice finish take some time and, you have plenty of that!

[RoboKlipsch]

I spent about an hour, maybe a bit less, wet sanding the cabinets with 600 grit.  I've never wet sanded before.  Lots of water with a touch of soap, sandpaper soaked in water, gentle sanding action.  It really smoothed the finish beautifully.

 

It also showed a few places where if I had sanded earlier it would have come out a bit better.  A few raised spots became a bit bare, so I touched those up with some diluted stain.  They look pretty darn good now, but the finish is of course dull from the sanding.  How smooth they are at 600 grit is impressive imo, I am surprised sandpaper can do this.

 

I plan to spray a bunch more coats of lacquer on over the next few days, let it dry and then go for the final finish.  Feeling confident now that I tried out the sanding and was able to do touchup.   I got a pack of sandpapers from 800 to 2000 and some polishes from Meguiar's.  As a former auto detailer, I realized I had a lot of experience with those stages.  When it comes to polishing compounds I must have done 100+ cars before, so those stages should be fun if anything.  

 

Home stretch......enjoying it and savoring the experience!

[RoboKlipsch]

4 more coats of lacquer applied, some pictures of what they look like while drying.

The camera angle can make them look glossy smooth or wet or dull, it shows exactly how they look, depending upon from what angle you're looking.

 

 

[derrickdj1]

You're done, thrown in the drivers and enjoy!

[fuzzydog]

Those look nice.  

[jjptkd]

Yes, very nice! I must say you are one very patient guy, I don't think  I could have waited for the glue to dry before tossing in one of those drivers and cranking it up!!

[RoboKlipsch]

20 hours ago, jjptkd said:

Yes, very nice! I must say you are one very patient guy, I don't think  I could have waited for the glue to dry before tossing in one of those drivers and cranking it up!!

 

 

It was one of the bigger surprises for me in this build.  I hoped and expected to build them in about a week.   Then I'd drop in the drivers, get them going and be off enjoying them.  Getting the boxes built was relatively quick, I'd have to go back and look but that took maybe a week or so.  I remember worrying that small things like the tnuts and bolts weren't going to be here fast enough and I'd be stuck waiting.

 

But as I built the sub, I realized that the choices I had were just that -- choices that determined what I'd be looking at for the next XX years, probably 10 or more.  I could have a working sub no matter the finish, but what did I want?  Paint still has a lot to it, priming, sanding, coats of paint and such.  It didn't seem all that easy, so I embarked upon the veneer finish.  Once I did that, and did enough reading, I realized that each step needed a certain amount of time.  And longest of all is the lacquer finish.  After the first 6 coats, I let it dry for a week, then wet sanded down to smooth.  After doing so, I saw that a few places needed touch up where the imperfect surface allowed the finish to be sanded down.  

 

So I decided to take 3 more days, when the weather was right, to add 4 coats per day to build a finish of 12 additional lacquer coats.  With spray cans (DEFT clear gloss finish), the layers are thin.  What's the difference you put on 4 more, 8 more or 12 more?  Really just some time.  More layers give me more to sand and finish without concern it may sand through the stain.  So after today when I've put on the last 4 coats (!), there will likely be another week or curing time before wet sanding and polishing.  Looking back I'm sure I will see many mistakes or places I could have done better -- but I won't look back thinking I "should have" done more!  

 

These steps are very easy now, but require patience and care.  It's been really fun, and I feel like I'll be much happier with the finished product after the extra work than if I didn't do it.  If I were to do this again in the future, I highly doubt I'd do it the same way.  Not because it won't be beautiful, but just because it's one of many ways to finish a wood veneer and a big part of the fun is learning something new.

 

I never would have thought -- ever -- that I'd be putting water onto the finish and sanding it, and that would be OK.  It never really occurred to me until I read about this that I was finishing the veneer with a product much like a car lacquer finish!  So there's a huge fun learning experience going on, where all these steps are new -- I've never done wood turning, but I now know what it is, the potential problems, and some of the methods that can be used to finish.

 

WITH ALL THAT SAID....AND I'M A WORDY GUY LOL....I am anxious to get them up and running. One thing that makes the time easy to deal with is that I purchased a couple of monster ported subs that are already in use in my theater.  So I can get down to 10hz with authority and can play up to reference easily (which I rarely do).  So the OMG I need good bass isn't there. But the idea of reenforcing my room, potentially able to put one sub in 3 corners and one in a "virtual" corner of the L-Shaped room and see the response and feel of that....pretty exciting.  I may put a couple behind the couch for nearfield, will have to see.  Goal #1 is great balance across the main seating positions (3).

 

Anyway, that's a really, really long answer, but it was a great point you brought up and one I have thought a lot about since I started.  In the end DDJ is right -- I've got time and doing it the way I want is more important to me than finishing fast.  After today, all that's left is some more sanding, polishing, and then wiring and bolting in the drivers.  I'm very much looking forward to it!    Timing-wise I expect it to be done within 2 weeks at the max.  Most of the time will be the cabinet curing.  

 

[RoboKlipsch]

Recap of finishing steps:

1) Sanding Sealer over glued cabinets.

2) Sanding of edges and sealer to create smooth lightly roughed surface.

3) Veneer application

4) Diluted dye applications.

5) Light careful coat of sanding sealer (without any soap additives).

6) Wood filler + stain.

7) Hand wiped sanding sealer (4 coats).

8) Lacquer spray can coats (6).

9) Cure for 1 week.

10) Wet sand with 600grit to create smooth finish, check, decide to proceed or spray more. 

11) Lacquer spray can coats (12 more, applied 4 per day).

12) Cure for a week or more. 

13) Wet sand with 800grit and increasing grits to 1500 or 2000 (TBD)

14) Polish with Meguiar's Swirl Remover.

15) Polish with Meguiar's Ultimate Polish

 

There's a lot there, and I never would have imagined I would do it all.  But we will see if it was worth it!

 

More Subwoofer porn to come after the final coat.  

[derrickdj1]

I've enjoyed watching this come together.  You took your time and did not rush things.  Great job!  Now you can enjoy these babies for years.

[eng-399]

The sub cabinet looks great! I really like the finish on them. I have four of these drivers myself and have them nearfield. I took out my 8 subs nearfield and replaced them with these legacy subs and have no regrets. The bass from 13-60 hz. is more than what I had. The entire riser seats and room shake with these on. I think your really going to like these in your ported box. I modeled them on winisd see picture for the parameters taken with Dats hooked up to the driver.

With you having these in a ported box your going to gain a lot in the lower fq. Here's a few pics of the driver for anyone who wants to see these to.
Keep it going your almost there.

After some eq with these and my four 18's in 4 LLT 20 cubic slot ported boxes behind my screen this was my rew graph.


If you need any help with eq, setting delays on these let me know I can help out.
Mike

[Scrappydue]

I always laugh when I see rew graphs with no smoothing. If I do no smoothing on omnimic it looks like a mountain range. 

[RoboKlipsch]

11 hours ago, eng-399 said:

The sub cabinet looks great! I really like the finish on them. I have four of these drivers myself and have them nearfield. I took out my 8 subs nearfield and replaced them with these legacy subs and have no regrets. The bass from 13-60 hz. is more than what I had. The entire riser seats and room shake with these on. I think your really going to like these in your ported box. I modeled them on winisd see picture for the parameters taken with Dats hooked up to the driver.

With you having these in a ported box your going to gain a lot in the lower fq. Here's a few pics of the driver for anyone who wants to see these to.
Keep it going your almost there.

After some eq with these and my four 18's in 4 LLT 20 cubic slot ported boxes behind my screen this was my rew graph.


If you need any help with eq, setting delays on these let me know I can help out.
Mike

It was great meeting you yesterday at the GTG!  How funny that I had read your thread a few times at avsforum and you happened to be at the GTG!  The only two people I know of who are using these drivers.  Thanks a bunch for the specs and offer to help.  I'm sure I can use both!

[RoboKlipsch]

4 hours ago, Scrappydue said:

I always laugh when I see rew graphs with no smoothing. If I do no smoothing on omnimic it looks like a mountain range. 

Derrick is the same way, they post these graphs that would normally require something like 1/3 smoothing for most and post them with a yawn lol!

 

One of the biggest challenges I found when eq'ing the subs was to get rid of the narrow peaks and dips.  It can be done but not easily.  The normal thought is to add or subtract from all the subs but what I found is that one sub or the other is actually causing the cancellation and LOWERING the output of one actually raise the response and smooth it out. 

[RoboKlipsch]

 

 

 

 

Here's my current room response.   My goal, which was ambitious, was to minimize variance across all 3 seats on the couch and weight them equally in value.

The complexity comes in with certain peaks and dips.  You can see in the above at certain frequencies, each seat is different.

 

If you look at 80hz, you can see how the room affects response.  That is the best I can do with 2 subs.  One seat has a peak, one has a dip, and the middle is in between.

I could improve 80hz across the seats, but at the expense of other frequencies.  

 

The room itself has some nice gain and the response is only down maybe 6 or 7db at 10hz.  

[RoboKlipsch]

Here is a link to eng's thread, over at avsforum where he builds 4 of these into one nearfield cabinet.

I followed this as I built mine, felt like I had a buddy working towards a simliar goal 

The difference between my slow careful build as a newbie and eng's powerbuild of a cabinet holding 4 in just a few days shows what a veteran builder can do.

 

http://www.avsforum.com/forum/155-diy-speakers-subs/2583025-nearfield-build-3-0-4-15-s-legacy-extreme-b-stock-drivers.html

[RoboKlipsch]

Here's a graph of optimizing the drivers to be wired in parallel @2ohms and run at 1040 watts, the max RMS through the Inuke3000 (and above the 800RMS the driver is spec'd to).  This is one driver/cabinet at 1m.  Subtract 6db for each doubling of distance from the MLP.   

 

Legacy 15 Optimized for NU3000DSP at 1040watts RMS.xps