Bottlehead Forum
Other Gear => Speakers => Topic started by: Wardsweb on November 16, 2009, 04:07:19 AM
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I thought I would post on my DIY horns. I actually started these around January 2006. Once they were built and dialed in, I didn't want to take them back apart for veneer because I was enjoying listening to them. Well having to take the speakers out of my living room for a new floor was the perfect time to actually finish the job.
To start, here is a picture of some of the internal construction; part MDF and part Baltic birch.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwardsweb.org%2Faudio%2FWidgets%2Fw02.jpg&hash=03df76c5d3c1ea327649782a97babc89f31bf015)
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The sides are four layers of kerf MDF that I filled with glass microbeads used in bead blasting.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwardsweb.org%2Faudio%2FWidgets%2Fw05.jpg&hash=6c56de145ccc7dc572b2d62e21d3a0696c904213)
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Here they are with the raw Sapele Pommele veneer on.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwardsweb.org%2Faudio%2FWidgets%2Fw41.jpg&hash=9d583b07cbb555433f157ae2bdcd7d6a4a64464d)
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This is with three coats of DEFT gloss lacquer finish. I will apply a few more coats, sand, polish and buff for a piano gloss.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwardsweb.org%2Faudio%2FWidgets%2Fw45.jpg&hash=d405bb44acebda92de0bd4e00dbeb85100d16bc0)
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Awesome! The veneer and finish are gorgeous!
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By the way the drivers are: JBL 2235H woofers, Altec 802-8G driver mounted to Altec 511B horns and JBL 077 slot tweeters.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwardsweb.org%2Faudio%2FWidgets%2Fw15.jpg&hash=c69d00fc296be58758bce2903e93d7f052ab9a18)
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Stunning. Courrently I am trying to learn how to veneer and finish several pairs of my speakers. Please post pictures when finally done.
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Stunning. Courrently I am trying to learn how to veneer and finish several pairs of my speakers. Please post pictures when finally done.
This is raw veneer that I used Better Bond Heat-Lock
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I can pretty much get the veneer on now, doing it just as you say. But I am still fighting the finish. Current method is to use sanding sealer, then spray on lacquer with HVLP sprayer, sanding between every two coats. Getting the right ratio of thinner to lacquer is so far sheer guess work. Then finally polish using an orbital car polisher and Griot's different levels of machine polish. My finished product looks OK, but not like the dash on a Rolls Royce, which is what I aspire to. There are still small errors, both in the wood and in the lacquer, that show on close examination. I have been practising by refinishing the bases of my Bottlehead gear (you can sand away like mad, which you cannot do on the veneer), and am now making a small pair of veneered speakers on which to experiment further. Have also ordered a book from the library on refinishing, so eventually I should be able to do it.
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I can pretty much get the veneer on now, doing it just as you say. But I am still fighting the finish. Current method is to use sanding sealer, then spray on lacquer with HVLP sprayer, sanding between every two coats. Getting the right ratio of thinner to lacquer is so far sheer guess work. Then finally polish using an orbital car polisher and Griot's different levels of machine polish. My finished product looks OK, but not like the dash on a Rolls Royce, which is what I aspire to. There are still small errors, both in the wood and in the lacquer, that show on close examination. I have been practising by refinishing the bases of my Bottlehead gear (you can sand away like mad, which you cannot do on the veneer), and am now making a small pair of veneered speakers on which to experiment further. Have also ordered a book from the library on refinishing, so eventually I should be able to do it.
Like a car finish, 90% of the work is in the prep. The smoother the surface the less you will need to work the finish. If you want the lacquer to level out your veneer, you will need to spray several very heavy coats or use the brush on and sand it smooth. Now this is somewhat old school. The same look can be achieved with more modern methods like urethane.
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That looks awesome!
Really nice veneer. Did you buy that locally or maybe online?
I've only done a little veneer work but I've finished miles of it. The trick is to sand the piss out of it without burning through it. The outside corners are the really tricky parts.
Getting a level finish is really dependent on the grain. Woods with open grain really take a lot of extra coats to level it out (I've never used a brush on filler but I know they're out there. You just need to be sure that it's ultra clear or your finish will start looking muddy.). There's a lot of sanding sealers that powder up really nice and don't take more than a couple of swipes with some 320 grit to sand most of it off. I've always done the sanding by hand but I did work on a Zebra wood table top that we used a random orbital on the last ten coats (used 5000 grit last).
Man, was that an expensive table when we got finished with it!
The amount of thinner you use depends a lot on personal choices. I used to add about a 1/2 gal to a 5 gallon can and add more along the way (with pre catalyzed laquer). You just don't want a bunch of sags to have to sand out. Take your time and be safe! (always plug your sprayer into an outlet outside of the spray booth. If the plug gets kicked out by accident,.. boom!)
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I'm also turning some 3" x 2" billet feet for them.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwardsweb.org%2Faudio%2FWidgets%2Fbarfinished.jpg&hash=8daf5796a659fb33d3a2ef34dbfb180d60c2c977)
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Beautiful speakers Wards..... are you able and/or willing to share dimensions and speaker impedance and sensitivity measurements? Perhaps the plans? I understand if not.
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Beautiful speakers Wards..... are you able and/or willing to share dimensions and speaker impedance and sensitivity measurements? Perhaps the plans? I understand if not.
The speakers are 44 1/2" tall by 25 1/4" at their widest point and 22 1/2" deep.
I don't know their actual impedance but know all drivers are 8 ohms and the crossover is based a combination of an Altec and JBL crossovers; both of which are 8 ohm.
Sensitivity I've never measures but it is high. The original 2-way I started with was around 104dB. I added the JBL 077 and swapped the Altec 416-8C for the JBL 2235H.
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I've held my tongue long enough...
Those look freakin' awesome!
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FINALLY they are back playing in my living room. I was going to leave the grills off but you will notice the left dust cap is dented. That is compliments of our 6 year old grandson and his marshmellow gun. You can't leave kids alone for two minutes. :(
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwardsweb.org%2Faudio%2FWidgets%2Flivingroom112809a.jpg&hash=21976d4a7e220e21d58adb09671942a9412ce78f)
My wife said she wants the full grills cut down so the big horn is showing. Sounds like a neat look. What do you guys think about a 3/4 grill?
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwardsweb.org%2Faudio%2FWidgets%2Flivingroom112809b.jpg&hash=b6f8c996af883fcb2300a3f03ae45a5f8c4ef371)
These have not been polished yet. I need to let them cure for a few weeks before I do that.
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I think they look awesome as is, with no grills. I'm surprised that your wife actually wants the big horns showing - that's the opposite response from what I would normally expect (i.e., "cover those damn things up or get rid of them!"...)
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I think a 3/4 grill, curved to match the horn lip, would look great. You can get (if you look around) metal perforated plate with a large percent open area, I think over 60% is available though not common. That's fairly transparent acoustically, especially below 5kHz. Perhaps a bit of black or gray soft felt between the grill and front panel would help minimize any residual cavity resonances...
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I think a 3/4 grill, curved to match the horn lip, would look great. You can get (if you look around) metal perforated plate with a large percent open area, I think over 60% is available though not common. That's fairly transparent acoustically, especially below 5kHz. Perhaps a bit of black or gray soft felt between the grill and front panel would help minimize any residual cavity resonances...
Way ahead of you Paul. I made full grills that follow the 22 degree arch of the speaker fronts out of perf metal, some JBL blue grill cloth and automotive trim edging. These are the ones my wife wants cut down so you see the Altec horns.
FYI: The perf is steel, 22 gauge, 1/4" hex x 0.285" on staggered centers. This makes it 77% open area. Purchased online from http://www.perf-plus.com
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwardsweb.org%2Faudio%2FWidgets%2Fw16.jpg&hash=9059ed524f535b2da4d32f7371a35ca574da4089)
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They are just spectacular. Can you share your crossover?
Thanks
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Here they are with full grills.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwardsweb.org%2Faudio%2FWidgets%2Flivingroom112909rightgrill.jpg&hash=75c1275ff91eaaccc48340bfdfc9d7a63e1fde3c)
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I can pretty much get the veneer on now, doing it just as you say. But I am still fighting the finish. Current method is to use sanding sealer, then spray on lacquer with HVLP sprayer, sanding between every two coats. Getting the right ratio of thinner to lacquer is so far sheer guess work. Then finally polish using an orbital car polisher and Griot's different levels of machine polish. My finished product looks OK, but not like the dash on a Rolls Royce, which is what I aspire to. There are still small errors, both in the wood and in the lacquer, that show on close examination. I have been practising by refinishing the bases of my Bottlehead gear (you can sand away like mad, which you cannot do on the veneer), and am now making a small pair of veneered speakers on which to experiment further. Have also ordered a book from the library on refinishing, so eventually I should be able to do it.
What kind of lacquer are you using and what are you thinning with? If you find yourself thinning quite a lot try moving up to a bigger nozzle on your HVLP. Are you using a turbine or compressor driven system? Nothing beats practice. And a bright halogen shoplight illuminating the work from the side can show imperfections and dust on your work that are otherwise invisible to the hands and eyes. Buy some good cabinet grade plywood to practice on and cut it into several chunks. Sand it with a random orbit 120-180-possibly 240 but no higher. Tack it off good, apply thinned vinyl sealer, scuff sand, and then start lacquering. If your shop temperature is reasonably close to 70 F, you should be able to sand and recoat within an hour or two. Let the final coat harden 24 hours or more before you try polishing. Unless you are sure of what you are doing it is a good idea to do your between-coat sandings by hand. 3M makes some foam rubber sanding pads that are fantastic for this step. I use the Superfine. They are about 3/16" thick and rectangular, grey in color with red lettering on the back. Their rectangular shape will just fit on an old-fashioned quarter sheet sander, which is what I use to speed things up. 3M scotch-bright pads can also be used, the gray ones are about right.
Gloss shows everything, and like a previous poster said, preparation is key. If there is a scratch, swirl, or dust spec in the sprayed finish, polishing will not make it go away.
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Wow, looks great, I am with you on the
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Do you have a schematic and/or picture of the crossover you used? I think I read on another site that you used an adjustable L-pad. Do you have any idea what frequency cut-offs you ended up at?
Those look like something that would be fun to try to build over time. If I was going to do it I would end up doing a regular square cabinet. I barely have the skills for that, but boy I would love to try. I find the Altec 846A I use are wonderful but they lack something in the bass, which isn't a big deal, but much more noticeable is the compression in the highs in complex passages. Whole bits of high frequency music are just missing when the musical passages have a lot going on. I imagine a tweeter could go a long way to remedying this. I would love to take a shot at something like what you built but toned down to my skill level. How about a consulting fee? :)
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Do you have a schematic and/or picture of the crossover you used? I think I read on another site that you used an adjustable L-pad. Do you have any idea what frequency cut-offs you ended up at?
Here is the final schematic.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwardsweb.org%2Fmisc%2Fa7_3106modcrossover.jpg&hash=550219ec3bfaf7227bcba7777b4a7e17f46f9535)
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Very helpful. I am seriously considering giving this a go, though the cabinet and quality of the actual components would have to be a little bit reduced from yours for the woofer and tweeter. Might try a super tweeter on my current Altecs first. But that looks like it would just be an absolute hoot to build and try out. If I go vintage the only truly sunk costs will be the cabinets. Everything else could be resold if it didn't work out. We'll see if I feel like I have the hutchspa to take on such an in depth project, my fear is screwing up the basic design of the cabinet. But thanks for posting the crossover!
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Here they are with full grills.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwardsweb.org%2Faudio%2FWidgets%2Flivingroom112909rightgrill.jpg&hash=75c1275ff91eaaccc48340bfdfc9d7a63e1fde3c)
I have to agree with your wife WW. I really like horns, they're kind of like breasts, I gotta see 'em. Does that make me horny..... Just askin'. Here I am, new to the forum, and I'll probably get myself in trouble.
Sorry, if I offended anyone!!
Ron
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Let's just say we like things in pairs: speakers, amps, tubes...
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Wardsweb,
The speakers really compliment the flooring. I recognize the table (where are the cold cathodes?), the CDP and I think I see a PS Audio P-??? at the bottom. But what are those amps next to the speakers?
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Wardsweb,
The speakers really compliment the flooring. I recognize the table (where are the cold cathodes?), the CDP and I think I see a PS Audio P-??? at the bottom. But what are those amps next to the speakers?
The cold cathodes are there (turntable & amp stands), just not turned on in the picture. The power conditioner is a PS Audio Quientessence. I swapped the Shanling T-100 for a C-T1500 a few months ago. The amps are Shanling SP-80 fitted with 6CA7EH. The biggest changes since that picture are the McIntosh C-36 and Juicy Music Tercel have been replaced with a SST Ambrosia preamp w/built in phono. The rack now uses one less shelf.
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Here is the new pic
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwardsweb.org%2Fmisc%2F2chnl_ambrosia.jpg&hash=2ce8b8ddfd933028d6b89dcf93b7ae4ddf261468)
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WW,
They're beautiful!!!! I have always envied your collection, and it seems it just keeps getting better.
I bet you're proud.
Take care,
Ron
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You did get the Ampzilla 2000 ! ! !
Awesome ! ! !
. . . Wait, they are hooked up to the horn? That is blood curdling!
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You did get the Ampzilla 2000 ! ! !
Awesome ! ! !
. . . Wait, they are hooked up to the horn? That is blood curdling!
The Ampzilla 2000 mono blocks are pushing the Martin Logan Prodigy's in the den. I use the Ambrosia preamp in the livingroom.