EDINGDALE speaker build

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Freddo
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#316 Chamfer and Bracing Panels

Post by Freddo »

Hello Toppsy,

Just wondering...when you put bracing panels in your tall speakers, is there any rule you follow when determining how many to include in the build (e.g., one every 15" or one per bass driver)?

Also, looking at your speakers where you chamfer the front edges, is there any special jig or tool that you use (pre- or post-assemby), i.e., router or table saw with a jig?

Thanks for any input you may have.
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Toppsy
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#317

Post by Toppsy »

Hi Freddo,

The placing of the bracing and the number of braces largely depends on the driver layout but for something of the likes of the Edingdales I find 2 vertical braces is sufficient when using 18mm Birch Ply. The trick is to make the spacing between each brace unequal along the length or height of the speakers. ie do not space them such they are say at 1/3rd distance each apart along the length. I always use 'window' braces as well routing them out from a solid panel so the 'frame' is around 30mm. In the case of the Edingdales the layout and spacing of the drivers determined rather nicely where the braces needed placing.

The chamfers to the front baffles are cut on a table saw using a long overhang fence as guide. For the fence post I use a 2440mm x approx 75mm off cut length of 18mm ply that would otherwise go in the skip when I have the basic panels cut on a flat bed CNC controlled table saw at my ply suppliers. I hold the fence in place to the table saw with 'G' Clamps.
Freddo
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#318

Post by Freddo »

Hello again Toppsy.

Thanks for taking the time to answer my queries.

Would it be okay if I asked just a couple more questions?

When you use the braces, do you rebate them into the walls of the speaker, screw them from the inside or just glue them using a tight fit?

Also, is the chamfer on all your speakers 45 degrees and is a straight chamfer preferable to a rounded chamfer?

Finally, on page six of the Edingdale blog on the right-hand picture at the top of the page, please look closely at the top right-hand corner of the plywood join on the face of the speaker. The front baffle plywood appears to be slightly forward of the plywood sides, as suggested by two ply layers of the baffle showing next to and in addition to the ply layers of the side. Is this just an optical illusion or is the baffle thicker than the thickness of the sides?

Sorry for the long-windedness and thanks again!
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Toppsy
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#319

Post by Toppsy »

Freddo,

The braces like all the other panels are CNC cut to size so are a tight fit. I do not recess them into the other panels just a but glued join. But there is no reason for not doing it the way you suggest. Horses for courses. It's just extra work having to route the recesses. However, if the panles were fully CNC routed for say flat pack kits then it would be easier to assemble with the routed rebates.

I use a 45 deg chamfer for aesthetics. You could round over the edges if you prefer but then try to veneer the speakers with a large rounded over edge on three sides to the front baffle. :roll:
Finally, on page six of the Edingdale blog on the right-hand picture at the top of the page, please look closely at the top right-hand corner of the plywood join on the face of the speaker. The front baffle plywood appears to be slightly forward of the plywood sides, as suggested by two ply layers of the baffle showing next to and in addition to the ply layers of the side. Is this just an optical illusion or is the baffle thicker than the thickness of the sides?
The front baffle is the same thickness as the rest of the speakers. What you are seeing is an optical illusion.
Freddo
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#320

Post by Freddo »

Thank you again Toppsy.

It's time to roll up my sleeves and get to work!
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Toppsy
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#321

Post by Toppsy »

Thought I'd add these American Black Walnut ones to the gallery of builds.

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Cressy Snr
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#322

Post by Cressy Snr »

Very nice Colin,
Bet your heart sank when the customer specified that veneer :wink:
Sgt. Baker started talkin’ with a Bullhorn in his hand.
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Toppsy
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#323

Post by Toppsy »

Yes it did some Steve, but this was the best of the rest he wanted.

His wife chose some rather expensive and difficult to do burr veneers. I chickened out doing those myself and got some quotes from a professional veneering Company for the burrs his wife listed. Cheapest quote was around £400 for the cheapest of the burrs. Most expensive burr I was quoted just under £500 for the speakers to be veneered!

In the end after a prolonged email correspondance he decided to go with the American Walnut as on your Metronomes. I had to order fresh stock as I only ordered sufficient last time to do your speakers. This time I got a full bundle and it went on surprising easier than your build. Either I'm getting better at this or (as I suspect) the new veneer is flatter than the stuff I got for yours which has made all the difference.

Anyway I'm chuffed with the results.
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Ali Tait
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#324

Post by Ali Tait »

They look very nice Colin.
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david C
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#325

Post by david C »

yep they do look good, I like walnut I'm just about to start an oiled walnut guitar body

have you tried TRU-OIL Colin?
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Toppsy
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#326

Post by Toppsy »

have you tried TRU-OIL Colin?
David, in a word no I haven't tried this type oil. Having done a little research since your posting the largest size bottle of this I can find is 8-oz and quite expensive. I buy Liberon Finishing Oil in 5-litre cans and I believe more suited to veneers rather than relative small area soild core wood.

I prefer to see the grain and texture of the wood rather than a super smooth high sheen finish for speakers. If someone wants a high sheen super smooth finish with all the grain filled in then I would use a varnish to achieve such a built up look.

I like the Liberon Oil as you can just brush on a heavy coating of the oil that soaks into the veneer, leave it for 10-mins and then wipe off the excess. When dry rub down with 0000 grade steel wool and repeat the exercise. So easy and guaranteed results to look good. A final buffing of Black Bison Polish rubbed in with the steel wool gives that final touch.
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#327

Post by zman »

This Liberon Oil looks very handy! Easy to apply, also simple to repair any damage.

From Colin's pictures, the finish is top notch too.
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david C
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#328

Post by david C »

I must admit that Finishing oil is great for speakers and furniture if you want to you can build up quite a gloss finish, did you know you can tint it?,

Tru-oil is more suited to gun stocks and guitars where you need a harder finish probably contains more polymers,
both are what Americans call wipe on poly
David

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Toppsy
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#329

Post by Toppsy »

I must say it is a rather nice feeling when you get an email from a 'customer' you made a pair of speakers for and they say such nice things about them. A few months back I made a pair of my Edingdale speakers skinned in Oak veneer for a guy who lives in South Wales. Yesterday I got this email from him:
Colin,

I've enough hours spent in front of The Edingdales now to warrant jotting down a few thoughts and sharing them with you.

The arrangement of the lounge in my small terraced house dictates positioning above all other factors, which results in the rear face of the speakers being only an inch from an exterior wall but I am able to separate them by three meters and listen centrally from four meters. My ears are level with the dust cap on the highest cone.

I have the ribbons attenuated by 5dB. The spikes go through the carpet and underlay and into concrete. The top surface of the boxes is square by spirit level, and toe-in, which I have not yet experimented with adjusting, is perhaps 5 degrees or so. By the way, do you know the horizontal dispersion angle of the tweeter?

My current vinyl source is a modified Technics 1210 including a Jelco SA-750D arm and London Decca Maroon cartridge. The phono stage is a GSP Revelation with linear PSU, amplified again by a Croft Micro 25 pre with a TJ 12AX7 in the line stage and the power amp is a single ended, Class A pentode design by Decware that will puff out about 4W when fed with 2V, utilising TJ and new old stock valves. I use Epiphany and Mark Grant interconnects and Tellurium-Q Black speaker cable.

I've run test tones and can hear upto 18kHz with ease at lower than 80db(A) and above 20kHz at higher SPLs. I'm guessing that the XO frequency is in the region of 3kHz. These tests suggest that response begins to fall off at about 40Hz in my room but I can hear a 20Hz sine wave clearly. I use an active sub that crosses over at 40 Hz, to reinforce the bottom octave. There is cabinet resonance at 125Hz, in both boxes.

The construction quality and finish to the cabs is first class and manages to combine the individuality of hand made craftsmanship with professional levels of presentation. I'm completely satisfied with my choice of veneer and it suits the room decor very well. The appearance, application and performance of the fittings, including the internal damping and the binding posts is superb.

I'm of the opinion that the transducers in a hi-fi system contribute most significantly to sound quality and, of those, the loudspeaker is the critical component. I have worked internationally in audio production for twenty years and in that time have listened to many drivers and cabinet combinations in reinforcement, monitoring and playback contexts. For the playback of pre-recorded mastered material, The Edingdale is the speaker that I would choose to listen to music through above all of the others that I have heard. The cohesive response of the driver array in your cabinets provides a musical coherence that betters, to my tastes,
all of the other designs that I have owned or demonstrated.

The soundstaging ability, even though the drivers are not heard as a point source in my arrangement, equals the wonderful sonic signature. The Edingdales have the 'magic' that I have sought for many years and to say that I am a delighted owner, is an understatement.

Good luck with your future designs and builds.
Regards,
John.
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Ali Tait
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#330

Post by Ali Tait »

Quite a compliment given his history Colin. Praise indeed.
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