Jump to content

Sierra

Another Troels Gravesen's DTQWT Project Build

Recommended Posts

Fantastic pics, thanks Sierra. I reckon you'll be done before November at that rate!

I'm interested in what sort of nice screws you found for the waveguide: they look like a hex drive, with perfect sized tops. I have black self-tappers from Jaycar, but they are just Philips head, and the heads are quite narrow. The best fit for the 7mm Deltalite holes I've found so far are 14ga self-tappers - perfect fit, if rather over-engineered, but will have to cover the silver with paint or texta.

I did get the recommended bolts and helicoil bushes from Jantzen, but I can't get the bushes to screw in straight, despite trials with 3 different drill sizes, so have abandoned that idea. 24 Euros later... Your Deltalite holes look quite large, so I'm wondering if you're going to use bolts and those pronged rear nuts?

With the routing of the rear chamfer: did you use an external circle for a profile, or somehow stick your pivot pin into something of the same thickness as the baffle? Looks like it'd be easy to get the wobbles up, with so little base to use.

Love the Jarrah: it's very fruity red, and makes the Tas "oak" look a lovely pale hue. I've avoided the usual bought "oak" so far, as it tends to go dark and depressing with old age (bit like looking in the mirror), but some of the gum trees cut here are very pale. I did find some 70 x 45 Baltic Birch here, but it's full of little knots, and I'm hoping to find some clear Celery Top to go next to some (also Tas) myrtle strips, like Troels does with Mahogany.

It's certainly a big project, putting these together. I've done 6 panels so far, and the learning curve is rather steep and tortuous.

Keep up the good work and photography for us!

Cheers again

Brian.

Share this post


Link to post
Share on other sites

It's looking stunning already!

There's a lot of work been put into that one...

SS

Thanks for the kind words SS ... still a bit more work to go yet.

@ BioBrian

Hopefully it will be complete in November sometime.

Regarding the screws I'm using for the waveguide .... you're right they are indeed hex head ... I've used 4mm x 15mm hex heads and also got 4mm flat washers to suit.

The big holes you noticed on the rear baffle of the Deltalites are because I am using the helicoil bushes even though they are annoying to try and insert straight.

To get the 45 deg chamfer on the inside of the baffle we simply used a 45 deg router bit which had a bearing guide and ran the guide along the inner edge of the cut out.

Hmmm ... I hope the Tasmanian Oak doesn't get darker over time ... oh well ... time will tell I suppose.

More pictures to come :)

Share this post


Link to post
Share on other sites

I love the look of Australian timbers when used to finish speakers of any kind. The workmanship in your build is very high, you will have a fine sounding speaker that also doubles as fine furniture.

Share this post


Link to post
Share on other sites

where can one buy the tasmanian or jarrah board?

Share this post


Link to post
Share on other sites


where can one buy the tasmanian or jarrah board?

I've used both Trend timbers and Anagoat timbers in Sydney. Either should have Tassie Oak, Jarrah and many others in stock.

Share this post


Link to post
Share on other sites

I love the look of Australian timbers when used to finish speakers of any kind. The workmanship in your build is very high, you will have a fine sounding speaker that also doubles as fine furniture.

Thanks LJT

That's exactly what I am after ... a speaker that is a nice piece of furniture as well.

The credit for the workmanship goes to a friend of mine, Brian McMillan from McMillan Fine Furniture in Ballarat (shameless plug) :)

where can one buy the tasmanian or jarrah board?

The timber for mine was sourced from Britton Timbers ... there is an outlet in NSW ... but any timber merchant should stock those.

Share this post


Link to post
Share on other sites

Some more pictures ...

Looking upwards into the horn showing the internal bracing ... also note the knife edge chamfering of the front baffle.

post-103929-0-33047500-1349563353_thumb.

post-103929-0-36563900-1349563525_thumb.

post-103929-0-32032300-1349563718_thumb.

Scallop routered on the internal radius panel of the horn for the Audax TW034XO-P47N Tweeter.

post-103929-0-57764200-1349563764_thumb.

post-103929-0-81080800-1349564075_thumb.

Felt lining panels cut out ready to be glued on.

post-103929-0-01161600-1349564130_thumb.

Felt lining glued on and polyester foam added.

post-103929-0-55969700-1349564175_thumb.

post-103929-0-76488300-1349564416_thumb.

post-103929-0-51809800-1349564632_thumb.

post-103929-0-07562300-1349564665_thumb.

Thanks for looking :)

Share this post


Link to post
Share on other sites


Looking good! Mustn't be long now till its all ready?

Share this post


Link to post
Share on other sites

Thanks Guys :)

Will still be a month or so away yet.

Will be another 2 weeks before I can get back to Brian's place in Ballarat and we can do the last bits of routing for the speaker terminals on the rear baffles.

Then the cabinets will go off to the polishers for the final finishing.

So probably the end of October or early November till I get the cabinets home and can start on the crossover installation and wiring etc.

Share this post


Link to post
Share on other sites

Keeping us dangling, there, Sierra. Does this mean you have a normal life as well??

I wonder what glue you used to stick the felt on. I tried somebody's recommendation of spray-on, but not not very convinced by the first test. Also heat-glue, but it hardens before you can get enough on: I had to do the last job in tiny strips. Good if it works: it penetrates enough felt to grab a reasonable amount. But those heat guns are a scandalously bad design/build! They (I bought a 2nd, bigger one) seem to go OK for the first packet of sticks, then you have to manually push the glue in...

I did my crossovers first, before starting on the cabs, and came up with a problem: the sketches differed from the circuit diagrams, in the order of capacitor/resistor in some cases. Troels' reply to my question was that the order doesn't matter, except where the expensive silver cap goes. I made mine according to the circuit. I later found a photo where somebody else had changed them back too. I wonder what you'll decide? (Crazikid? Buzz?) The heat glue worked well for sticking the components onto the boards. You have to be quick, as it sets so fast, but one error was corrected by re-melting with a hot knife, hopefully without damage.

These massive (over 2.5kg per speaker) crossovers make me wonder about the ones in my present 3-ways, with their little polyester and electrolytic caps. There can be no looking back after DTQWT...

Share this post


Link to post
Share on other sites

Not too much has changed since the last update BioBrian ... just doing long hours at work at the moment.

For sticking the felt on I used the good old Selleys Contact Adhesive ... I wouldn't use anything else.

Yes I noticed that the crossover layout differed from the photo's with the resistor/cap orientation ... but Troels mentions that it differs in the text just underneath the layout so I hadn't thought more about it.

I had planned to follow the layout rather than the photos.

Although I might send Troel's another email to confirm it really doesn't make a difference since you've mentioned that there is an exception with the Silver Caps.

They are massive crossovers as you say ... makes my current 3 way speaker crossovers look whimpy too!

To glue the really heavy C-Core inductor I've used liquid nails and also used it on the big wax coils.

For all the other components I'll be using a neutral cure silicone adhesive/sealer.

I hope to have some more updated pictures after the weekend ... but for now ... just for you Brian ... a couple of pics of the start of my crossovers :)

Heavy C-Core and wax inductors glued to MDF bases with Liquid Nails

post-103929-0-34821300-1350298381_thumb.

post-103929-0-44992700-1350298422_thumb.

Share this post


Link to post
Share on other sites


I used sikaflex for the internal felt and crossovers.

I was unhappy with the way the jantzen silver cap was sounding so I sprung for some duelund caps for both the tweeter and mid range driver. I know the jantzen silver caps need to be run in - But they sounded like finger nails across a white board. Cost a pretty penny. Also changed to eichmann cable pods. All my internal wiring is goertz. Much better than the silver plated stuff that came with the kit.

Share this post


Link to post
Share on other sites

Hi Sierra,

Just thinking out loud here . .

What's the conventional wisdom with gluing these heavy cross-over items?

Might the Liquid Nails start to sag over time? . . or is it best to add a couple of nylon zip-ties to be sure?

Edited by Dustin

Share this post


Link to post
Share on other sites

I used sikaflex for the internal felt and crossovers.

I was unhappy with the way the jantzen silver cap was sounding so I sprung for some duelund caps for both the tweeter and mid range driver. I know the jantzen silver caps need to be run in - But they sounded like finger nails across a white board. Cost a pretty penny. Also changed to eichmann cable pods. All my internal wiring is goertz. Much better than the silver plated stuff that came with the kit.

Sikaflex will definately work well :)

Interesting that you replaced the silver caps James ... did it change the overall sound much?

Which Duelund cap type did you go with ... VSF, VSF Black or Cast?

As well as the silver cap ... did you also replace both Sup-Z caps with the Duelunds?

I don't think my ears would be good enough tell the difference between the goertz wire and the silver plated one that comes with the kit.

But that's the great thing about speakers like these ... future component upgrades are an easy thing to do if needed.

Hi Sierra,

Just thinking out loud here . .

What's the conventional wisdom with gluing these heavy cross-over items?

Might the Liquid Nails start to sag over time? . . or is it best to add a couple of nylon zip-ties to be sure?

Hey Dustin

Liquid Nails is a strong construction adhesive and is designed to flex and not crack with temperature changes. No ... it will definately not sag over time.

I've seen others that have constructed their crossovers holding the components on with zip-ties ... personally I think it looks untidy with zip ties ... but thats just me :)

Share this post


Link to post
Share on other sites

duelund vsf for 5.6 silver and 6.8uf superior z cap.

Share this post


Link to post
Share on other sites


Was there much difference to the sound one you replaced the caps crazikid?

Share this post


Link to post
Share on other sites

big difference i'm afraid. price to upgrade - $800. so not a cheap option.

Share this post


Link to post
Share on other sites

Wow ... $200 a cap!!! Definately not a cheap option ... but an option non the less.

Are you happy with them now?

The first thing I'll be doing is running mine in ... I'll put at least 200 hours on them before having a proper listen :)

Now onto another progress update ...

The front and rear baffles have been assembled onto the cabinet.

The front baffles have had the edge chamfered.

And the cabinets have been vaneered with Tasmanian Oak.

post-103929-0-61738800-1350771028_thumb.

post-103929-0-22097300-1350771142_thumb.

post-103929-0-56064600-1350771227_thumb.

The next step is to router the rear baffle to flush fit the speaker terminal binding post plate

post-103929-0-38732000-1350771307_thumb.

I'll post up some more pics later today :)

Thanks for looking.

Share this post


Link to post
Share on other sites

Wow ... $200 a cap!!! Definately not a cheap option ... but an option non the less.

Are you happy with them now?

very happy

Share this post


Link to post
Share on other sites

Crazikid: Interesting about your caps move, and I'm very interested in the sound improvement, if any, long term, notwithstanding your driver break-in period, which I haven't read about. In regard to your pics from 17th of Aug, did you chamfer your front baffles according to Troels' requirements? It's a bit hard to tell from the photo, and I don't know what stage they were at then.

Sierra: thanks for the updates, and after Troels' comments "never again" about fitting binder posts after fitting the rear baffles, it looks like you've chosen a smart option. Are they of insulating material, and where did you find them?

I personally am struggling with the whole idea of binder posts. It only takes one brush against them with an audio-head's tape measure to short out the amplifier, and that they make speaker leads with conductors with bare ends, and of equal length, also defies belief. For all my recent speakers, including the 8 of the HT setup, I've (perhaps heretically) used the Canon-type plugs. I know they are normally used for mikes, but they look like they can handle sufficient current for speakers, and if installed correctly, they are very quick to plug in, they have a very satisfying "snick" to lock in, and are solid, and remove any late-night thinking problems in regard to polarity. I'd welcome any comments, there, folks.

I really love the BFA plugs/sockets that come with the Cyrus etc amps. They are just perfect. Why on earth don't they make them for the other end of speaker cables???

The only other possibility I've found that still lingers is Anderson connectors. They don't seem to have a panel plug/socket, but their line connectors are better than sex. The feeling of insertion and connection has to be felt to be understood. They have various current ratings, with red/black ones of 30A and 75A, and in paired configuration: 50A, 120A, and 175A. They even give the number of kg of pull required to disconnect! They are apparently used for low voltage/high current applications, eg fork-lift batteries, and can be found on p201 of the current Jaycar catalogue. Comments? (I'm expecting an Inquisition to start here...)

With my DTs, I blew a few hours today making and gluing in the myrtle "inlays", and am waiting for inspiration as to how to finish the rest of the chamfered baffles. I'm finding the Baltic Birch ply impossibly delicate: I had to make a new baffle part after just grazing one with the straight-edge. It is SO soft. I've started applying wood sealer, to make the panels survive the build process a bit better: tools like the power saw, and even the router can leave deep gouges in it if there's an invisible piece of grit lying about. I'm hoping that routing the circles, with sealer on, will reduce the edge damage that Troels warns about.

After your comment, Sierra, about WAF, I should explain that I feel I have freedom to build what I like, living as I do on 123 acres on my own. But there are some interesting aspects surfacing after the gloating, more of a psychological nature. The speakers are actually too big for my man-cave cabin-in-the-bush, so they could potentially trigger a very expensive and expansive change of my living arrangements! I think underneath I'm hoping the famous "WAF" would somehow translate itself into a question from my long-lusted-after partner-to-be: "hey I love your speakers - WAF?"

Got to keep the dream alive...

Share this post


Link to post
Share on other sites

The Anderson connectors are sensational for high current applications, and have a "wiping" style contact. I haven't used them for speakers but I can't see there being any problems...

Regards,

SS

Share this post


Link to post
Share on other sites

Crazikid: Interesting about your caps move, and I'm very interested in the sound improvement, if any, long term, notwithstanding your driver break-in period, which I haven't read about. In regard to your pics from 17th of Aug, did you chamfer your front baffles according to Troels' requirements? It's a bit hard to tell from the photo, and I don't know what stage they were at then.

Sierra: thanks for the updates, and after Troels' comments "never again" about fitting binder posts after fitting the rear baffles, it looks like you've chosen a smart option. Are they of insulating material, and where did you find them?

I personally am struggling with the whole idea of binder posts. It only takes one brush against them with an audio-head's tape measure to short out the amplifier, and that they make speaker leads with conductors with bare ends, and of equal length, also defies belief. For all my recent speakers, including the 8 of the HT setup, I've (perhaps heretically) used the Canon-type plugs. I know they are normally used for mikes, but they look like they can handle sufficient current for speakers, and if installed correctly, they are very quick to plug in, they have a very satisfying "snick" to lock in, and are solid, and remove any late-night thinking problems in regard to polarity. I'd welcome any comments, there, folks.

I really love the BFA plugs/sockets that come with the Cyrus etc amps. They are just perfect. Why on earth don't they make them for the other end of speaker cables???

The only other possibility I've found that still lingers is Anderson connectors. They don't seem to have a panel plug/socket, but their line connectors are better than sex. The feeling of insertion and connection has to be felt to be understood. They have various current ratings, with red/black ones of 30A and 75A, and in paired configuration: 50A, 120A, and 175A. They even give the number of kg of pull required to disconnect! They are apparently used for low voltage/high current applications, eg fork-lift batteries, and can be found on p201 of the current Jaycar catalogue. Comments? (I'm expecting an Inquisition to start here...)

With my DTs, I blew a few hours today making and gluing in the myrtle "inlays", and am waiting for inspiration as to how to finish the rest of the chamfered baffles. I'm finding the Baltic Birch ply impossibly delicate: I had to make a new baffle part after just grazing one with the straight-edge. It is SO soft. I've started applying wood sealer, to make the panels survive the build process a bit better: tools like the power saw, and even the router can leave deep gouges in it if there's an invisible piece of grit lying about. I'm hoping that routing the circles, with sealer on, will reduce the edge damage that Troels warns about.

After your comment, Sierra, about WAF, I should explain that I feel I have freedom to build what I like, living as I do on 123 acres on my own. But there are some interesting aspects surfacing after the gloating, more of a psychological nature. The speakers are actually too big for my man-cave cabin-in-the-bush, so they could potentially trigger a very expensive and expansive change of my living arrangements! I think underneath I'm hoping the famous "WAF" would somehow translate itself into a question from my long-lusted-after partner-to-be: "hey I love your speakers - WAF?"

Got to keep the dream alive...

Troel's comments about fitting binding posts after fitting of the rear baffles had been in the back of my mind ...

I had been tossing up the option of using a binding post plate instead of the binding posts that bolt straight through the baffle (as came with the kit) as I think it looks a bit more "upmarket" after seeing a couple of user built versions on Troels website.

So in the end I decided to go the way of the binding posts and mounting plates ... the ones I got are from Dayton Audio.

The mounting plate is made from anodised aluminium and the binding posts themselves are insulated through the mounting plate hole.

With the added benefit as Troels alluded to ... will make connections to the crossovers a painless experience.

To be honest I didn't even think of insulating the binding posts ... and in my home situation it's not something I need to worry about.

I never connect speakers with the amplifier turned on ... so an accidental "short" across the speaker binding posts when connecting speaker cables is a

non issue for me.

I know there are a number of other types of connectors available as you mention with the Anderson plugs and Canon connectors etc ... but not my cup of

tea ... what I have will do the job just fine :)

I'm guessing the Baltic Birch ply is your finished surface if you have had to remake parts after a straight edge dent ...

Sounds like it's a tough material to work with being so soft ... damn.

You'll have to take it really easy as you get the cabinets together as they will become heavy (really heavy in your case) and could be "dinted" by their own weight should you need to lay it on packers or something like that.

Is vaneering over the top an option for you to cover the odd dint or graze?

Good luck with the "hey I love your speakers" - WAF if you have to change your living arrangements :P

The Anderson connectors are sensational for high current applications, and have a "wiping" style contact. I haven't used them for speakers but I can't see there being any problems...

Regards,

SS

Not really a high current application here ... kinda like shelling a peanut with a sledgehammer :P

Hi guys,

Sorry to go off topic but I believe that if you want solid, reliable and high-current connectors then why not borrow from the pro-audio world?

http://www.neutrik.com/en/speakon/

These are going in my next build.

Cheers,

Mike

Definately a good reliable option with those connectors.

Share this post


Link to post
Share on other sites

Time for some more pictures :)

Routering out the rear baffle for the speaker binding posts.

post-103929-0-90360800-1350914561_thumb.

post-103929-0-12521000-1350914587_thumb.

Template made up as a router guide to flush fit the binding post mounting plate.

post-103929-0-10677100-1350914630_thumb.

post-103929-0-20656900-1350914668_thumb.

Binding post mounting plates test fitted.

post-103929-0-75181800-1350914695_thumb.

post-103929-0-30233600-1350914731_thumb.

And that pretty well completes the fabrication of the cabinets themselves.

The next step is to send the cabinets off to the furnature polisher where they will be finished off to a high gloss with a 2 pack clear.

post-103929-0-69594800-1350914763_thumb.

post-103929-0-36581800-1350914849_thumb.

post-103929-0-28302000-1350914883_thumb.

post-103929-0-23488900-1350915071_thumb.

post-103929-0-49299700-1350915123_thumb.

post-103929-0-18285100-1350915158_thumb.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Classifieds Statistics


    Currently Active Ads

    Total Sales (Since 2018)

    Total Sales Value (Last 14 Days)

    Total Ads Value (Since March 2020)
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...