B460 - The Twins [Archive] - Lansing Heritage Forums

RedCoat23

10-05-2014, 11:39 AM

So I'm currently making progress on my mirrored B460 clone to go with my original. I used the plans on the site for my measurements and 1inch ultralight mdf for material.

I still have quite a lot to do. Only the base is currently dowled and glued, the rest is just a dry fit to see how it looks.

Trimming for dimensions - either the values in the library postings are incorrect or my cutting isn't exact, but it looks like I have a 3mm difference in one piece.

Even larger; the base section is marked as 76mm in the plans and yet my original is 94mm, so I'm going to have to cut a new base frame. (I want them both to match).

I have to make the 11 degree cuts to my front panel and chamfer the base and top piece to match.
The internal bracing pieces are not yet done
I have the pipe pieces but not yet cut and I'm going to include a cut out frame for support to the pipes inside the cab.
Obviously veneer to be done yet too - going for walnut to keep it traditional.

But it's coming together :)

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Mr. Widget

10-05-2014, 12:57 PM

So I'm currently making progress on my mirrored B460 clone to go with my original. I used the plans on the site for my measurements and 1inch ultralight mdf for material.Beautiful!

A pair of those will be amazing and having them mirror imaged will definitely look cool.

The internal bracing pieces are not yet doneI'm not sure what the originals used, but I would recommend KD 2x4s and as many as possible. You might also want to add a bit of mass to the walls before you add the fiberglass. A mineral filled mastic of some type should do it. Years ago I used the ultra light MDF because it was easier to work with and I definitely noticed that the cabinet was not as dead as traditional MDF.

Widget

JBLP

10-05-2014, 02:42 PM

Good job!
I'm very interested in "the making of".
I will follow you.
Paul

RedCoat23

10-06-2014, 09:49 PM

Thanks Widget,
I'll bear that in mind when it comes to bracing the interior. Ultralight was all that available in 1inch at the time, but was a lot easier to move :)

I'm having a look at some choices for wall dampening, will be easier to apply before I fully assemble all the pieces. Will update the thread again at the weekend, no time to work on it before then.

Best Regards

RedCoat

audiomagnate

10-16-2014, 05:27 PM

I didn't know they made an Ultralight. I've always thought the 460 was beyond cool. I'd love to have a few.

RedCoat23

10-16-2014, 09:41 PM

Update.
Well work is in crazy mode right now and I'm doing 7 day weeks, so I've had no time to look at this since my last posting. It's likely to be this for another few weeks yet.

I didn't know they made an Ultralight. I've always thought the 460 was beyond cool. I'd love to have a few.

I love the sound of the single B460 I have now. It's powered from an Emotiva XPA-1 monoblock via a minidsp. The 500w is plenty :). My mains are 4412a's, but I'm trying to consider what else I should pair the subs with once finished. (Other than a 250 or 250ti that is)

rdgrimes

10-17-2014, 05:09 AM

Update.
I love the sound of the single B460 I have now. It's powered from an Emotiva XPA-1 monoblock via a minidsp. The 500w is plenty :). My mains are 4412a's, but I'm trying to consider what else I should pair the subs with once finished. (Other than a 250 or 250ti that is)

Pair them with anything you like. :)

The nice thing about multiple subs is you can experiment with placement. Resist the temptation to put them where they look best, (they are beautiful). Especially in a large room, start with them on opposite sides.

RedCoat23

08-15-2015, 11:27 PM

Life has a habit of getting in the way... Anyway after a very long hiatus I thought I'd update the thread. I've spent the past 4 weekends working on the sub

First update - shows all the sides are complete and caulked. The back plate to mount the terminals was just fitted here and caulked.

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Here's another shot from the rear showing the cutout

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The following weekend I put in the port tubes. The next shot is the day after I'd epoxied the port tubes. These are just slightly smaller internal diameter than the original plans - 4 inches as opposed to the originals at 4.125 inches. I calculated the original volume based upon 4.125 diameter and 14.75 length. I extended the ports based upon the new diameter to 15.69 inches and I'm within 0.02in3 of the original volume.

At this stage I had not yet used the flush trim bit to clean up the excess epoxy.

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Here's a better shot of the interior. I'd sprayed the interior of the tubes flat black. Note there is no bracing at this stage.

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A shot from the other end. You can also see the t-nuts in place for the front baffle.

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Continued in the next post...

RedCoat23

08-15-2015, 11:28 PM

This is a better shot of the port side showing the excess epoxy to be cleaned up.

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Finally, today's work. I was attaching the last internal brace, along with putting bondo in some areas.

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For tomorrow. I'm finishing up the base. I didn't like that I had MDF (even painted) on the floor, so I'm attaching a piece of 5mm plywood to the base. I plan on sealing the footer area with duratex and going for a smooth finish.
This week I have my absorption panels for the inside arriving. I also have the fiberglass bat ready to go. Next weekend the plan is to complete all the interior preparation and do the roundover on the lid before final box assembly. Expect further updates...promise! ;)

dprice

08-20-2015, 05:53 PM

Keep up the good work! I've got a B460 though I've never really thought seriously about giving it a twin.

4343

08-20-2015, 09:06 PM

Nice!

MDF is not the best at retaining Tee nuts. Give a thought to using a small piece of thin ply screwed in behind the Tee nuts. Drill holes so the bolts can pass through and screw it on between the two nuts to keep them from ever falling inside the cabinet...

I've futzed around enough with them falling inside to never want to do it again, and to know that the perfect time to make sure they can't fall out is before sealing them inside a box.http://www.audioheritage.org/vbulletin/images/smilies/blink.gif

RedCoat23

08-20-2015, 11:25 PM

Keep up the good work! I've got a B460 though I've never really thought seriously about giving it a twin.

Well I have a pair of 4412a's that I'm currently using with my original and there's a height difference between the speakers from one side to the other j/k, but seriously I like symmetry and mirroring gives me the option of having the ports inside or outside. Finally as Grimes points out I can use the second to even frequency distribution across the listening space. Besides it's a good exercise to engage in given I have a full set of drivers for both a 4345 and 4355 just waiting for some construction time...

Nice!

MDF is not the best at retaining Tee nuts. Give a thought to using a small piece of thin ply screwed in behind the Tee nuts. Drill holes so the bolts can pass through and screw it on between the two nuts to keep them from ever falling inside the cabinet...

I've futzed around enough with them falling inside to never want to do it again, and to know that the perfect time to make sure they can't fall out is before sealing them inside a box.:blink:

Thanks for the tip! I'll tackle that change this weekend.

I got my binding posts today along with mounting kit from dougie (t-nuts, clamps etc.) Will be updating the thread with further pictures tomorrow and Saturday.

wrager

08-21-2015, 06:31 AM

Are you using the 2245 woofer? Will you equalize too? I am building a traditional 8 cu ft (net) cab with 2x6" ports using my 2245.

RedCoat23

08-21-2015, 02:18 PM

Yes I am using a 2245 woofer and a minidsp to equalize - following the same parameters used in the BX63.

Champster

08-22-2015, 01:38 PM

Yes I am using a 2245 woofer and a minidsp to equalize - following the same parameters used in the BX63.

Red-You're going to love these subs!!!! Beautiful build!

RedCoat23

08-23-2015, 05:54 PM

Okay I'm including some images from last week that I neglected to post.

First is the addition of the 5mm plywood base that was glued and furniture nail tacked on the base. You can see from the image it was oversize. I used a flush trim bit to tidy up the edges.

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The next is after flush trimming. Those dowels you can see were to pin the base board in place. The side panels for the footer are doweled together so I had to put in the base and the drill/dowel through the sides. These have yet to be bondo'd. The entire base will have duratex on so they will not be visible.

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Now for this weekend. The first task was to roundover those sections of the cabinet that required them. For this I used Freud's 1" round over bit (34-132 (http://www.freudtools.com/index.php/products/product/34-132) ). It's a fairly large bit and requires a 2.6+" opening on your router - seen here fitted to my Festool OF1400. A four cutter design, made like a hot knife through butter on the MDF.

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Final two images show the results.

Lid - obviously not yet mounted.

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Underside - I got lucky here. The edge of the routers footer resting against the side of the box was just the right distance to complete the round-over. Especially given the round-over bit is designed to rest a bearing on a 90 degree surface for guidance but in this instance is not present in the design of the cabinet.

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RedCoat23

08-23-2015, 05:54 PM

As 4343 suggested I added some capture wood behind the T-nuts should the worst happen. Instead of screwing directly into the face - I was concerned about splitting the baffle this far down the road. I decided to channel just enough space to clear the T-nuts and allow the wood to be directly glued to the baffle.

Here are the wood pieces. I just used a laminate trim router for these quick and dirty - no measuring ;)

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Finally one in place

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The rest of my day was spent applying the surface dampening sheets followed by the insulation batting on all surfaces. Here's a shot from work in progress.

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Work remaining.

I have to re-cut the top lid again. All the tightening and clamping with the dowels has meant the lid doesn't fit exactly so I need to make a new one. I have a few edges to tidy up. Fitting the lid is going to be a challenge with dowels but I like the positive registration it provides so I'm going that route. Does mean all the drilling has no room for errors...
Then I'm on to surface preparation before those areas to be painted can be tackled. Finally the veneering. My plan is to have the lid cut mounted and insulated by the end of next week so look out for upates!

Best Regards

FE3T

08-27-2015, 04:18 PM

The following weekend I put in the port tubes. The next shot is the day after I'd epoxied the port tubes. These are just slightly smaller internal diameter than the original plans - 4 inches as opposed to the originals at 4.125 inches. I calculated the original volume based upon 4.125 diameter and 14.75 length. I extended the ports based upon the new diameter to 15.69 inches and I'm within 0.02in3 of the original volume

Smaller diameter = Shorter tubes if you want the same tuning.

If Your original B460 has 3 Ø4.125" tubes x 14.75" long
and Your mirrored copy has 3 Ø4" tubes they need to be 13.77" long, not 15.69"

But i dont know if the difference are audible, it may not be. :)

RedCoat23

08-27-2015, 06:59 PM

You're right. Don't know how I missed that. :blink:

Using an online calculator having a 8ft3 box with 4.125 diameter tubes at 14.75 length gives a tuning frequency of 26.8Hz. Changing to 4 inch diameter and moving out to 15.69 just means I've altered the box tuning from 26.8 to 26.12Hz (if I did the maths correctly). So I guess you're right, chances are I'm not likely to notice the difference, but thanks for spotting the error. :)

RedCoat23

09-06-2015, 06:06 PM

Didn't get to mess with the clone last weekend so here's the small update for this weekend.
I finally got to fit the lid to the box!
Here it is with all the clamps I could find - Note to self, need more... I used some table saw frame rails as cauls, they worked just fine.

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After 24 hours and now with all clamps removed, but before edge clean up

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Finally the reason I didn't do any work last weekend. I put some entertainment in the garage to make the work more enjoyable ;)

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I've subsequently cleaned up all the edges. Redone the roundover and bondo'd any sections that needed it. It's starting to feel like I might just finish it this time :p

dprice

09-07-2015, 05:42 AM

RedCoat23

09-07-2015, 11:37 AM

Nice call on the 1" roundover bit. I was wondering how you were going pull that off. I had to build a replacement grill frame for mine and ended up faking the roundovers by making a few passes on the table saw to rough out the profile. Then I used a belt sander and finishing sander to get the final profile.

BTW, are you working from a set of plans? Or just figuring it out from your original?

I wasn't going to build a grill for mine. My original doesn't have one, plus I have cats. Grills and cats don't mix...

In answer to your question I'm working off the metric plans on the site, though I had to make some adjustments - as documented earlier in the thread - my footer section is taller than those called for in the site plans so I re-built the base. They are now within 2mm of each other.

RedCoat23

09-20-2015, 04:30 PM

Didn't get a chance to do much last weekend hence the lack of update. This weekend I sprayed the front baffle and rear panel.
I used one of my damaged 2245 drivers (has coil rub, needs new cone) just to get a sense of how it will look finished.

It's getting closer! :)

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And here's a shot from of the back panel.

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It'll probably be a couple of weeks again before I'm able to update, hopefully it'll show the base complete with the touch up work on ports also done; only veneering will remain.

RedCoat23

10-24-2015, 04:34 PM

Here's an update I neglected to post. I was working on the base of the cabinet painting with Duratex

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Though the colour is slightly different from the main baffle, it's not really noticeable and I feel actually turned out quite well.
I'm using 8 furniture sliders from home depot.

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RedCoat23

10-24-2015, 04:40 PM

Today I applied walnut veneer to the end caps of the cabinet. I used weldwood contact cement and a veneer hammer.
I veneered directly over the 3 ports and then used flush trim bit after drilling a suitable sized hole in the centre.

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A slightly better angle. Those blue painters tape lines indicate where the centres of the port holes are.

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Finally after all 3 holes are complete.

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Tomorrow I'll be attaching the final piece of veneer (top and front). Will post once done.

Ed Zeppeli

10-24-2015, 07:52 PM

Excellent progress. Thanks for all the detail.

Are you planning on finishing with Watco?

Cheers,

Warren

RedCoat23

10-24-2015, 08:10 PM

Excellent progress. Thanks for all the detail.

Are you planning on finishing with Watco?

Cheers,

Warren

Thanks Warren, it's certainly taking me a while! :)

Yes I'm using Watcho Danish Oil medium walnut. I did a test piece from one of my offcuts last weekend, matches my original B460 really well.
The plan is to post pics of the two of them side by side once complete.

I'm a little nervous about the final piece - it's giant 'L' shape but I think I've figured out how to do it without drama...I hope... :blink:

RedCoat23

10-25-2015, 06:47 PM

Today's the day for the final piece. Here's where it was this morning as I was checking for about the 12th time how much overhang I had and exactly where it needed to be placed.

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This was after I'd completed attaching the veneer in one piece but without any edge trimming. I used a veneer hammer to press the two surfaces together. The painter's tape was just to catch glue from the roller

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Top and left side edge trimmed. I'd not got the book-matching perfect but close enough. I figure once the stain is on, it'll probably be less noticeable

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Final shot of the box complete. I've done first pass edge trimming. the brown wavey edges you can see at some of the corners is part of the paper substrate that still needs removing. I also have some touch up to do on the black painted surfaces where the flush trim bit got a bit too flush...:blink:

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I'm leaving the glue a week to fully cure before I start staining next weekend. I'll be doing a restore pass on my original at the same time. Sunday I plan to photograph them side-by side so look out for that.

In closing I just wanted to say that this is the first woodwork project I've undertaken since leaving school about 30 years ago. I went to the trouble of detailing a lot of my steps for those who are perhaps a little reluctant to undertake such a project. My advice, take your time, measure 10 times and cut once (maybe...), but above all have fun. I've really enjoyed my journey with this.

Best Regards

Redcoat.

JeffW

10-25-2015, 06:59 PM

Great work on an ambitious project, looking forward to seeing the finished product!

RedCoat23

10-26-2015, 09:49 PM

Great work on an ambitious project, looking forward to seeing the finished product!

Thanks Jeff :) It's almost done.

mech986

10-28-2015, 08:06 PM

RedCoat23

10-29-2015, 11:12 AM

Redcoat, a stupendous project and execution.

A possible tip - when you were laying the L-shaped veneer with full matched grain, you could have considered either:
Cutting the veneer at the top curve and glue back at the line, making the process a lot easier with two rectangular pieces
or clamping some vertical pieces to help define the borders of each straight edge surface, even with the front curved section, making alignment a little easier.

Tough though to take such a large veneer piece and get it to lay evenly while you're simultaneously gluing and pressing it down - did the veneer seem to stretch at all?

Hi Mech,
Thanks for the kind words. Yes I'd considered cutting into two rectangular pieces. I was concerned I'd screw it up when it came to attaching the second piece. The veneer was paperbacked from Oakwood and felt really flexible in regular handling so I thought I'd throw caution to the wind and see if I could do it in one piece. I did the top of the box first and got my wife to hold the front 'L' out straight. I'd also placed a big sheet of parchment paper over the front glued face just in case.

Once the top was on and I was satisfied, I worked slowly bending it over the curve and down the front rolling back the parchment paper. There was a point that it seemed to have shifted slightly. That the entire piece hadn't been laid exactly parallel to box. The veneer was really close to not meeting the edge of the left-hand side of the front panel. In the end I had about 1mm overhang after bending it around the bottom curve, but 1mm was enough...just! I'd call it a win. All in all though I think I would do it in two pieces next time. All part of the learning process :D

RedCoat23

11-01-2015, 01:29 PM

So I've reached the end of the road...hurrah! :D

Here's my last collection of images. These are after the first coat of Watco Medium Walnut

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And a teaser before the last image, this was after using Restor-a-finish and Feed and Wax on the original. Not quite the same hue on the walnut, but I'm not complaining, it still turned out well.

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