Another Troels Gravesen Jenzen build.

[awkwardbydesign]

I thought I ought to start my own thread here instead of kibbutzing Phil's.
This build started last year, and the speakers have been running since midnight on 22nd December. If that sounds rather precise, it's because I was having an operation on my hand on the 23rd, and if I didn't get them running before then, it would be several weeks before I could continue!
Anyway, I made it, but haven't touched the crossovers since then, and they WILL need some tweaking. I won't post all the pics, as some of them are very similar to Phil's, so I'll mainly document the differences.
My cabinets are 24mm, 18mm birch ply plus 6mm MDF, with the fronts 18 + 6 + 18mm. These are screwed on at the moment, but will be glued when I have finished routing the edges. At the moment I am veneering the new sand filled side cheeks, which is a pain. My veneer is old and splits easily, but it was cheap!
The tops will be 15mm sandstone set into oak framing.
The carcasse is biscuit jointed, glued AND screwed. I believe in overkill!
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/13122013014_zps7ddb8e7a.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/19122013039_zps57c2f151.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/21122013047_zpscf974b32.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/22122013051_zpsdb501b46.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/23122013059_zpse105a4ff.jpg
I started out using some SEAS bass units I had, but quickly found they weren't suitable, so bought the specified type.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/03012014075_zps053537da.jpg
Phil sent me some reticulated foam for the ports, which wedge in easily.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000015_zps60345c2f.jpg
I stained the fronts black, just to see how they would look (they will be covered with black leather similar to Sonus Fabers), and put bars over the drivers to protect them from grandsons with rucksacks! It turns out my wife likes the look so they will be staying. They may all be brass in the end.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000069_zps0e56720f.jpg
After a while I felt the midrange could be improved, so I earned enough to replace them with the Nextel W18NX001 drivers. Crossover is still the same for now, but I emailed Troels with some questions, so it will soon be modified, as they are a bit brighter than the old mids.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000195_zpsec51ffbc.jpg
When the sand filled sides are ready to fit, I will trim the front panels, rewire and modify the crossovers. Then work on the TL stuffing.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/20140511_115849_zpspq8aeq4a.jpg
I have had some success with Townshend style stands, so will make some to fit these speakers and see how that works. I use 2 inner tubes, which means I can adjust for tilt.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/SeismicSinks005.jpg
At the moment Massive Attack is rattling away, but these speakers seem very sensitive to cabling; I've changed the speaker cables from silver plated stranded to Polk Cobra litz, quadrupled. Makes quite a difference, so I will try changing the internal wiring too, and run direct from the crossover to the drivers with no breaks.
Well, that's where I am at the moment, and as soon as they sound half decent I want to host a bake-off to try different amps. I need to know what the limiting factors are before I try to fix problems that may be nothing to do with the speakers!

[falcoron]

Looks superb mate well done can't wait to see them when completed

[awkwardbydesign]

Progress is slow, partly due to trying to work out how to apply the veneer without visible joins. Changes in humidity mean the veneer expands and contracts, and matching filler is hard. I am now trying to pre-lacquer the veneer to stabilise it and then cut and glue it. Anyway, here is what they should look like when they are fixed; these are only propped up to have a look. My wife still likes them, and that is half the battle. The stands/bases will match, and there will be a solid oak trim around the top, with a 15mm limestone slab inset.

http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000199_zps2183d8ba.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000198_zpsc5bbd424.jpg

The fronts need the edges chamfering and the black leather applying before the sides are glued on. Which will be very heavy when they are sand filled!
From where I sit, nearly face on to the right speaker, they look rather muscular with the curved sides, almost like hunched shoulders. I rather like that, it gives them presence, especially with the grills. I am quite surprised that my wife likes those!
I am waiting for drier weather before I lacquer the veneer, so it hopefully won't shrink anymore, so I think the next job is to make the new larger crossover boxes to go on the back, with sloped sides to make them less visible from the front, and I guess I'll veneer them too. Crossover changes mean I want extra room for more or bigger components, like C core inductors or Russian PIO caps.
http://www.audio-components.co.uk/media/content/c-coils-225.jpg http://thumbs1.ebaystatic.com/d/l225/m/mo0sp3Ck04ZpAu6w8822-AQ.jpg

[awkwardbydesign]

I've been looking at other TL designs, including ones I have built myself, and one thing stands out compared with Troels'; the port is generally at least as big as the line. Troels makes his smaller, and I wonder if this is causing back reflections at some frequencies. Of course, this may have all been taken into consideration, and if it's working OK then there is no need worry about it. However I am not satisfied with the bass performance, and I stress this is in MY room with MY amplifier (a temporary one at that), with MY speaker positioning (with which I am stuck), so I plan to widen the port slot out to full width. At the moment it has an area of 150 sq/cm, the line is 270 sq/cm, and the bass driver is 350 sq/cm. The relationship between the driver and line is reasonable, but I am dubious about the port. If I recut it to better match the line, I could easily add fillets to reduce it again if I am wrong, without disturbing the front finish, but not increase it after the leather is applied.
Also I will stuff the line like the Chris Rogers PRO9TL, a design I built many years ago, and which worked well. Of course that was in a different room, etc. I still have plenty of wool, so it won't cost me any extra, just time and effort!
Phil is happy with his performance, so it may just be my room, and as I am pretty much stuck with the positioning, this could work for me. I have built enough TLs in the last 40 years to know how good they CAN be, but never in this house.

[337alant]

Very nice build :eyebrows:;);)
How do they sound
Alan

[awkwardbydesign]

Well, the bass isn't right yet, and the treble was a bit fluffy and sibilant. But yesterday I looked at the grills over the tweeters and wondered......... They are about 18mm from the dome, and I worked out that wavelength equated to 17-18 kHz (I think!). Half wave is 8.5-9 kHz, and a reflection would try to cancel at that. Anyway, I took the 2 outer bars off and what do you know, it sounds better! Now I may be fooling myself here, but if it makes me happy, who cares? I'm definitely getting somewhere now, but until the cabinets are finished I can't really tune them. I will do some measurements then and move them around, just to see what happens. I just hope I can finish them before I get to old to move them! :lol:

[awkwardbydesign]

Not fooling myself after all. How can removing 2 little brass bars (2.3mm brazing rods) make such a difference? Reflections? Refraction? I don't know, but these speakers are far more sensitive to small changes than I expected. I am hoping that adding notch filters as Troels did to the NEXT version will clean it up further, without killing it. The new crossover boxes are nearly made; I will veneer them next. Do I use matching oak, or wenge? I have both, and dark may look better round the back. Decisions, decisions.
http://www.style-partitions.co.uk/assets/Uploads/products/product-swatches/wenge3.jpg

[f1eng]

There is a good chance that those rods are buzzing away when excited themselves by the music just next to them. Metal has pretty well zero internal damping.
Try touching them very lightly when playing music and see if you can feel any vibration. If you can feel it at all you will be able to hear it. (try lightly touching the mid-range unit when playing to get a feel for the level of vibration you can hear).
I was amazed when I first tried it.
That is when I became a fan of extremely dead speaker cabinets.

[awkwardbydesign]

Hi Frank, I thought of that, and the bass bars have enough tension in them to ring if I flick them, but the little brass rods on the tweeters were not tight in their holes; not under tension, and damped by the fluffy nature of the ply. So I don't THINK they resonated, anyway I couldn't feel any, but who knows, you may be right. They're staying out anyway, one is enough to protect the tweeters, but I will try removing that one too when the crossovers are upgraded.
A question, for anyone really, is it worth using Mills non-inductive wirewound resistors instead of Jantzen MOS or Superes 10w resistors, especially in the tweeter section? I know some people think it is an improvement, but I have no experience with them. Z foil resistors made a difference in my DAC, so I know resistors CAN sound different, but that is a different application.
I agree about killing cabinet vibrations, that is why I am making the sand-filled side panels. And if I can isolate the top cabinets from the bass cabinets, I will do that too. Plus some new Townshend style isolation plinths. It costs me very little to do these things, mainly time.
Anyway, I have been busily veneering the crossover boxes today (I decided on oak; it was easier!), even though they will be unseen round the back of the speakers. I intend to hang them on rubber rings, to isolate them from cabinet vibrations; I don't know if it matters, but it's another doubt out of the equation, and easy enough to do. If I can find some chunky handles to use for hanging them, they will double up as transport handles.
http://media.bellacor.com.edgesuite.net/images/500/93575126171.jpg

[awkwardbydesign]

Crossover boxes made, veneered and lacquered. I should get out more!
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000201_zps10c8df2f.jpg
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000203_zpsdd68f940.jpg

[oceanobsession]

Very nice they look great, im new to woodwork, never done any veneering to date

[awkwardbydesign]

Very nice they look great, im new to woodwork, never done any veneering to date
If you ever do any, try to get the paper backed type. I've been using raw unbacked oak veneer, and as it's old and dry (therefore cheap!) it keeps expanding and shrinking with the changes in humidity. And cutting long straight edges (to join two or more pieces invisibly) has been very hard. I'm obviously not as good at it as I remember, although I seem to have got the hang of it with the very last panel. Number 8! I gave the veneer a coat of lacquer first, to stabilise it, trimmed it with a sharp knife and a straight edge, then used sandpaper on a long block to get it to match up. And using a short pile roller for the pre-cat lacquer means 2nd and 3rd coats don't drag previous coats, as the solvents will soften the lower layers.
It's now time to modify and relocate the crossovers into their new boxes, and rewire with more of the Polk/Monitor Audio litz cable. I've measured the old steel supports for the top cabs, and will weld them up to their new lengths. This is to try to separate the top boxes from the bass cabs, which worked well for some earlier speakers.
Maybe they will be finished this year!
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Isobarics%20November%202012/04052013806_zps458754bd.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Isobarics%20November%202012/04052013806_zps458754bd.jpg.html)
I'm also looking for a Jungson amp, similar to Troels' but there don't seem to be any around.

[walpurgis]

I know exactly what you mean about working with oak veneer. It warps and won't lay flat and as you say cutting a straight edge, especially along the grain is tricky. I have used it successfully, but I'd sooner work with just about any other wood.

[slate]

I can see that the quality inspector approves of the veneer Work...

[awkwardbydesign]

I know exactly what you mean about working with oak veneer. It warps and won't lay flat and as you say cutting a straight edge, especially along the grain is tricky. I have used it successfully, but I'd sooner work with just about any other wood.
How about yew? :lol: And I have some old wenge with a surface like corduroy; it splits into strands as soon as you touch it!


I can see that the quality inspector approves of the veneer Work...
I think he's bored with it all!

[awkwardbydesign]

All 8 side panels veneered and lacquered. A small roller with short pile head worked well. The joins are adequate, just a bit of light staining on the edges that were exposed, but I wasn't going to trim it all off, as they are sides not fronts.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000205_zps6dc054e9.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/P1000205_zps6dc054e9.jpg.html)

I wanted some 64mm D handles to hang the crossover boxes, but I couldn't find any locally. http://www.cookebrothers.co.uk/images/cabinet/d_handles.jpg
So I bought some 4mm threaded studding and 6mm aly tube (which has a 4mm hole through it). I'll slide the studding through the tube, leaving a bit sticking out, bend the composite rod into a D, trim to size, and have a 6mm D handle with an M4 thread sticking out of each end. Creating, in effect, a solid rod means it shouldn't collapse at the bends. Actually cheaper than buying 4 handles, and I can make them deeper than standard too.

[awkwardbydesign]

D handles made and fitted; not perfect but they will do. Switches installed, they are ready for the components now.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000209_zpsa23b75c6.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/P1000209_zpsa23b75c6.jpg.html)

I think I will cut and weld the steel top box frames next, and insert some M6 cross dowels in the top cabinets. http://i.ebayimg.com/t/4-X-M6-Cross-Dowel-Barrel-Nuts-Chair-Bed-Cot-Bolts-20mm-/00/s/MjQ2WDMwMA==/$(KGrHqV,!oMF!Z9krnbTBQRZ8Wi62!~~60_35.JPG

[awkwardbydesign]

Anyway, back to these things-
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Isobarics%20November%202012/04052013806_zps458754bd.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Isobarics%20November%202012/04052013806_zps458754bd.jpg.html)

They used to suspend earlier top cabs thus-
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Isobarics%20November%202012/07052013808-Copy_zps23fbb9e2.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Isobarics%20November%202012/07052013808-Copy_zps23fbb9e2.jpg.html)

They now look like this-
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/2014-06/b56c1bfd-facc-42b2-8927-edc548a689de_zps0c74c336.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Mobile%20Uploads/2014-06/b56c1bfd-facc-42b2-8927-edc548a689de_zps0c74c336.jpg.html)
I veneered the uprights to match the cabinets. They will be hardly visible, but why not? I will bolt the top cabs from the back into them and see if it makes a difference. At the moment I have just removed the sorbothane feet from between the cabs (on the advice of oceanobsession) and it has improved the sound, but I will still try this method. If it doesn't work I can just unbolt them and revert to a more usual configuration.

[awkwardbydesign]

Now I have pair of those trouser stands you get in hotel rooms.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/2014-06/dc6a92cb-6afc-480e-b515-344fd3e1651d_zps3f5e028c.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Mobile%20Uploads/2014-06/dc6a92cb-6afc-480e-b515-344fd3e1651d_zps3f5e028c.jpg.html)

They will form part of the bass stands, but run up the back without touching the bass cabs, and the top cabs will bolt to them. I decided to fill them with expanding polyurethane foam to try to damp any ringing. I've never really used it before, but what could possibly go wrong?
BTW, how do you get it out of your hair? :rofl: It oozed out everywhere; it's probably still doing it. And getting it off the veneer without stripping the lacquer took some thought. I had to get at it before it dried, so I used white spirit and elbow grease. That's a couple of hours I'll never get back! I've still got to do the other one, and to be honest, I don't think it's very effective. :doh: I'll stick to sand filling next time. Next time?:eek:
And the crossover boxes are too wide to fit between the rails! I'll trim them and re-veneer the exposed mdf. It would probably help if I had a cunning plan at the beginning, instead of making it up as I go along. But as fatmarley said, where's the fun in that?
Still, I'm actually enjoying the sound of them now, although there is more to come from them. Although the design is Troels', I'm using my own experience and ideas to (hopefully) improve them. There are some points where I disagree with him, so we'll see who's right.

[awkwardbydesign]

I cut down the crossover boxes, so they would fit between the stand rails. :doh:
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/20140614_141639_zpsv1pd2fkf.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/20140614_141639_zpsv1pd2fkf.jpg.html)

And made up the HF and MF internal wiring. Used some of the Polk/Monitor Audio litz that I had.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/20140614_141906_zpsedv34tp9.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/20140614_141906_zpsedv34tp9.jpg.html)

I'm running out of excuses not to dismantle the speakers and finish the front panels and veneer the backs. I'm putting it off until absolutely everything is ready, as I won't have any music for as long as it takes to finish them. :(

[Macca]

Crossover boxes look amazingly good. I like that you are making it up as you go along, planning is for wimps!

[awkwardbydesign]

Crossover boxes look amazingly good. I like that you are making it up as you go along, planning is for wimps!
Ooh, I'm having that for my signature!

[awkwardbydesign]

It seems I moved a picture and lost it. So here it is again; don't get too excited.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/20140610_164106_zpsgorpy8st.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/20140610_164106_zpsgorpy8st.jpg.html)

[awkwardbydesign]

Just a little something I've got ready. Any guesses where they fit?
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/dce53038-0e28-45e0-9255-6d8e0aae5681_zps75567ad8.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/dce53038-0e28-45e0-9255-6d8e0aae5681_zps75567ad8.jpg.html)

[alexm84]

Did you use the T25C003 tweeter or the T25CF001 that has the fluid?

I am going to build these and i'm not sure which tweeter would be better. Can't find much online about the difference other than the fluid.

[awkwardbydesign]

Did you use the T25C003 tweeter or the T25CF001 that has the fluid?

I am going to build these and i'm not sure which tweeter would be better. Can't find much online about the difference other than the fluid.
I used the 003 without ferrofluid. As I understand it, the ferrofluid allows greater power and volume, as it it cools the tweeter. But as I have also read various comments that it doesn't sound as good at sane levels, I decided not to use it. I listen more at low level than high. I may be mistaken, but that was my reasoning.
Curiously, the 001 is cheaper than the 003 from Audio Components, who I use. http://www.audio-components.co.uk/store/SubSubCategory.asp?SubSubCategoryID=139

[awkwardbydesign]

A little more done, the top box backs are veneered. I had some wenge veneer, so I used it. Bloody hell, if the oak was fiddly, this stuff is worse! Apart from the lethal splinters, it just splits into strings. And the dust is horrid.
I've also inserted the threaded steel dowels into the sides, so I can bolt the boxes to the steel back supports. I need to work out the force on the top bolts and find springs that will give me some acoustic isolation. Or at least that's the theory!
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/20140625_165855_zpsnmyp4h5x.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/20140625_165855_zpsnmyp4h5x.jpg.html)

I didn't really need to bother with the backs, but in for a penny.......

[Gordon Steadman]

i agree about Wenge, 'orrible stuff. One of my tutors persuaded me to use it for the trims on one of my guitars. I cursed him for weeks. You can imagine the fun I had bending it for purflings and bindings. Even soaked for a few days before the bending iron, it split all over the place. If you look under a magnifying glass, you can see all the places I had to fill with superglue and dust:eek: (Actually, it was probably epoxy and dust back then, I don't think superglue was around in that epoque - or should that be epoxy?)

[awkwardbydesign]

I'm not even bothering with sanding sealer, or filling the joins with this. It's only the backs, and I'm losing the will to live! I started these nearly a year ago!
I've borrowed a pair of Neat floor standers, but I can't wait to get mine back, even without them being tuned.
I bought a CD yesterday, Toumani and Sidiki (Diabate) dueting on kora. I suspect I will be using it to voice the speakers; it nearly had me in tears even in the car! If I can't re-capture the magic with these speakers, then they are plain wrong! If you can play track 5, "Lampedusa", in memory of the boatload of migrants who drowned last year, it is absolutely haunting!

[Gordon Steadman]

I'm not even bothering with sanding sealer, or filling the joins with this. It's only the backs, and I'm losing the will to live! I started these nearly a year ago!
I've borrowed a pair of Neat floor standers, but I can't wait to get mine back, even without them being tuned.
I bought a CD yesterday, Toumani and Sidiki (Diabate) dueting on kora. I suspect I will be using it to voice the speakers; it nearly had me in tears even in the car! If I can't re-capture the magic with these speakers, then they are plain wrong! If you can play track 5, "Lampedusa", in memory of the boatload of migrants who drowned last year, it is absolutely haunting!

A year:eek:

What patience you must have. I was running out of the will after two weeks with the Teufels. Maybe because it was the second pair but probably just because I'm an impatient bugger.

[awkwardbydesign]

Not patience, injuries! And lack of a cunning plan.

[awkwardbydesign]

The top boxes DO hang from the steel supports without collapsing! I wasn't 100% certain it would work safely, but phew! it does. I will have to damp the bolts and bracket, but it seems OK so far. When I fit the fronts, drivers and sand filled side panels the weight will more than double! I may then need the 2nd set of bolts at the top. At least they wouldn't fall very far, as they are only 10mm above the bass cabs. I wonder if I could make it a little more complicated? :scratch::doh:
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/2014-06/20140626_124759_zpsuhtlua6h.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Mobile%20Uploads/2014-06/20140626_124759_zpsuhtlua6h.jpg.html)
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/2014-06/20140626_124828_zpsrnzt0j8u.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Mobile%20Uploads/2014-06/20140626_124828_zpsrnzt0j8u.jpg.html)

[Firebottle]

You have my admiration, for the build and the patience :clapclapclap:

[awkwardbydesign]

And the stupidity!

[awkwardbydesign]

Well done me. I seem to have lost some photos by moving them in Photobucket! I'll try to put them back.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/20140626_124751_zpsihhodwme.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/20140626_124751_zpsihhodwme.jpg.html)
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/20140626_124828_zpsrnzt0j8u.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/20140626_124828_zpsrnzt0j8u.jpg.html)

OK, I think they are the right ones.
And the midrange fronts are now finally fixed on. I have screwed them onto a non setting mastic bead, so I can remove them without destroying the whole cabinets, in case I can ever afford Accuton mid drivers. The screw holes are filled flush so they won't show when I glue on the leather, which is the next step. The tweeter panels will be mounted on sorbothane and just lift out if I want to change them.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/20140702_141448_zpshnqzgmmt.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/20140702_141448_zpshnqzgmmt.jpg.html)

Once the leather is glued on, I can stick the sandfilled side cheeks on. The fronts are cut 1mm narrower on both sides to allow for the leather to fit under the cheeks. The top surface will be treated after they are up and running, an oak surround with limestone panel glued on. Probably!
And I can run them as a two way until the bass cabs are finished, hopefully.
I fear I will die of old age before they're done.

[awkwardbydesign]

Leather fronts glued on, and the side cheeks fixed to one of the boxes. They're getting heavy now. I would like to use urethane elastomer springs on the back bolts, for suspension. but not easy to find. I may have to use compression springs (valve springs?) or cast my own.
I've cut some thin MDF as a temporary top, which will also be the template for the final tops, a la Sonus Faber.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/2014-07/bdd6f2b5-f259-47f3-bccc-da2fe1a0a033_zps1df64119.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Mobile%20Uploads/2014-07/bdd6f2b5-f259-47f3-bccc-da2fe1a0a033_zps1df64119.jpg.html)
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/2014-07/20140704_180653_zps5ejggp8c.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Mobile%20Uploads/2014-07/20140704_180653_zps5ejggp8c.jpg.html)
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/2014-07/43831569-f5c7-4065-888d-7dbad7677a1d_zps2fda8af1.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Mobile%20Uploads/2014-07/43831569-f5c7-4065-888d-7dbad7677a1d_zps2fda8af1.jpg.html)

The tops will be done like this, but with a cream limestone slab instead of leather. It's lucky I'm on the ground floor!
http://1.bp.blogspot.com/-L8QGrzo_vLw/UY3epOkcIhI/AAAAAAAAJwU/4RR_PnRcBgU/s640/munich_2013_show_highend_high_end_report_matej_isa k_mono_and_stereo_sonus_faber_olympica_devialet_ne w07.jpg

[awkwardbydesign]

One box brought in and hanging from the steel frame. I strained my back lifting it, I'll have to get helpl with the other one! I've used the template for the final top as a temporary top.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/20140705_121701_zps88262f1a.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/20140705_121701_zps88262f1a.jpg.html)

[awkwardbydesign]

Both in now, and the tweeter panels covered and mounted. I followed Troels' sorbothane method, the panels are cantilevered and can be just lifted out. When the glue dries I will cut out the circles for the tweeters.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000222_zpsc4683897.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/P1000222_zpsc4683897.jpg.html)
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000225_zpsc675a333.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/P1000225_zpsc675a333.jpg.html)
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000226_zps8ed333e9.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/P1000226_zps8ed333e9.jpg.html)

I had to make some quick stands for the little Mordaunt Shorts. The cheap B&Q saw table was a really good buy!
http://i1134.photobucket.com/albums/m604/awkwardbydesign/P1000216_zps80045ebf.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/P1000216_zps80045ebf.jpg.html)

[awkwardbydesign]

Just spent the Germany v Brazil match teasing out long haired wool for the transmission line. Kept getting distracted by those pesky Germans scoring goals. Rather a lot of them. Hopefully tomorrow's match will let me get on a bit better.

[Koning]

Well, there were far fewer goals. None, actually. Dutch got knocked out by penalty kicks. Hope you're happy :mad: :eyebrows:

And on a more serious note, how are the speakers coming along? Man, you are certainly not one for taking the easy route :respect:

[awkwardbydesign]

Still at it. Football tonight, so I can finish fluffing the wool. Should be boring as it's a pointless match.
There is a vase of flowers on top of one of the speakers; I've told my wife she is allowed to do that now. Part of my cunning plan to make the speakers more acceptable! The tops will be limestone with an oak surround, so "vase friendly". I'll seal the edges well in case there is spillage! The current flowers are gladioli, they nearly reach the ceiling!
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/2014-07/db4eaae7-0d41-4083-a2ba-3ae72cf8e622_zps191772e5.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Mobile%20Uploads/2014-07/db4eaae7-0d41-4083-a2ba-3ae72cf8e622_zps191772e5.jpg.html)
I'm hoping to get the bass cabinets finished this weekend. No promises mind. I'll have to make up the crossovers before I bring them in, though, otherwise I'll have nowhere for the temporary speakers to fit, so no music.
And I now have a workshop cat. Not my cat though!
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/2014-07/4c0a513a-7073-41bd-9449-df8aaf8be4f2_zpsd6f39160.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Mobile%20Uploads/2014-07/4c0a513a-7073-41bd-9449-df8aaf8be4f2_zpsd6f39160.jpg.html)

[awkwardbydesign]

I've just struggled my way through converting a Word doc. to a jpeg. I hate computers!
Anyway, this is the line stuffing I'm following. The Pro9TL from 1976! I used it then and I will see if it's still valid. If not, I have access to the whole of the line to change it around. The theory behind it is to damp the 5th harmonic, so divide the line length by 5, and damp those points. I'm using wire mesh to stop the wool sagging; it's scratching my hands to buggery!
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/Pro9TLStuffing_zps7140dfa3.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/Pro9TLStuffing_zps7140dfa3.jpg.html)
Wrong way up, of course.

[awkwardbydesign]

All the wool fluffing is done. One cabinet has had it's top veneered and the leather applied to the front. It weighs 30kg without the bass driver or the sand filled side panels. I reckon it will double in weight! I need to find a spring rate calculator so I can make some isolating feet, like the Townshend Stellas.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/20140713_183119_zpshrbmm1d4.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/20140713_183119_zpshrbmm1d4.jpg.html)
And the tweeter panel matches too!
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/20140713_184522_zpspqvszcmd.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/20140713_184522_zpspqvszcmd.jpg.html)

[awkwardbydesign]

The side panels are filled with sand, just need to veneer the top edges with wenge. After which I hope never to touch the stuff again! They have bowed very slightly, so I will have to clamp them tightly to straighten them as the glue dries. And as they are curved I have had to make clamping braces to stop slippage or damage. There are six of these, as some sides have bowed out, and some have bowed in. I wonder if I can make it a bit more complicated?
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/20140717_171844_zpsjw2dgz9y.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/20140717_171844_zpsjw2dgz9y.jpg.html)

The crossovers now need to be rebuilt in their new boxes before I bring the bass cabinets in, or there will be no room for the temporary speakers I am listening to at the moment.
I have weighed one of the side panels, and they weigh 13kg each. That means each bass cab will weigh 60 kg! Add 10kg for the steel mid cab supports, and an estimated 30kg (or more!) for the mid cabs and we have about 100kg for each speaker. Just as well I am on the ground floor on a solid floor.

[awkwardbydesign]

One speaker has the side panels clamped on. When the glue dries enough I'll slide them up the little ramp I made, onto the base of the steel frame. I say slide, as they now weigh 56kg, without the bass driver (4.5kg). I had to do this in the living room, I can't carry them!
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/d6733136-f8e2-485f-82d6-8fb1cc0b6e47_zpse0dbdf58.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/d6733136-f8e2-485f-82d6-8fb1cc0b6e47_zpse0dbdf58.jpg.html)

I'll do the other one tomorrow, it's time for a glass of wine now.

[walpurgis]

Very nice Richard, good progress. They'll look excellent. :)

[Macca]

One speaker has the side panels clamped on. When the glue dries enough I'll slide them up the little ramp I made, onto the base of the steel frame. I say slide, as they now weigh 56kg, .

Weighs how much? I give you your due you are not mucking around here. I suspect that cabinet will be quite 'inert' as they say...

[awkwardbydesign]

If you add the the mid/treble cabs and the steel frames it will be about 100kg. And if you try the knuckle rap test you get sore knuckles! I need to source some springs for the feet of the bass cabs, like the Townshend pods. I spoke to someone at the local uni today, so I'll try to get them to do the calculations for me.

[awkwardbydesign]

Left speaker in position. The top cab is fixed to the steel frame, and the bass cab sits on the steel feet. No other contact between them, in fact I slid the bass cab into place without moving the top cab. Just need to level the top one as the the gap is about 2mm out on one side. The right cab is clamped and drying, so it will go in tonight.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/1f1215ad-1d78-4cc6-adf5-7276f85ff56b_zps022b685f.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/1f1215ad-1d78-4cc6-adf5-7276f85ff56b_zps022b685f.jpg.html)
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/77f4f40e-2262-44f1-a3c7-d4855e7ff607_zps17ff0f83.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/77f4f40e-2262-44f1-a3c7-d4855e7ff607_zps17ff0f83.jpg.html)

If I had been really clever the veneer would have lined up, but I was losing the will to live.

[awkwardbydesign]

Both speakers in place, and I used a bit of 3mm oak veneered ply (cupboard back; I buy cheap furniture from the local auction house and cannibalise it for the wood. Lots of cheap oak, elm too!) to make temporary plinth fronts. Just ripped it to width, chamfered the ends and stuck it on with tape. Cost nothing and took about an hour. The grills are on again, apart from the tweeter grills, so I will drill those and install the drivers. Just the crossovers to do then. Of course there will be endless fiddling thereafter, but that's another matter.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/51aa578b-692e-45ad-9bbb-ece8c54937a9_zps8e8fb6e6.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/51aa578b-692e-45ad-9bbb-ece8c54937a9_zps8e8fb6e6.jpg.html)

I'll have to try to get someone to take some decent pics!

[synsei]

Erm, they're quite big aren't they? :D

Lovely job though and they do look very smart. I'm assuming the bars across the driver cut-outs are a temporary measure... :eyebrows:

[awkwardbydesign]

:donk: Nope, they're permanent! I put them in as an experiment and my wife likes them; so they're staying! They may end up all brass, but other than that, that is the finished look. Apart from the tops, a la Sonus Faber, and the feet.

[awkwardbydesign]

One crossover done, I'll try to do the other one over the weekend. They take a lot of time, especially as I am combining the ER and NEXT circuits, plus switched HF and MF attenuation. I've had 6 tabs open on the laptop and toggled between them comparing layouts! Some careful checking and testing before I use it. They will hang down the backs of the bass cabinets on elastic. Probably hair elastics.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000240_zpsfa4c515c.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/P1000240_zpsfa4c515c.jpg.html)

http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/P1000243_zps8097a031.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/P1000243_zps8097a031.jpg.html)

I've used some cheap ferrite cored inductors that I've had for about 30 years, just unwound them to suit, and polyester caps from the parts box. This is just for the tweeter response shaping; if it seems to work OK I'll replace them with better ones.

[awkwardbydesign]

Both crossovers finished now. Just need checking carefully, a few prayers, and plug them in. Too late tonight, tomorrow will do.

[awkwardbydesign]

And...... they work! :dance:
Still plenty of tweaking to do, line stuffing, crossover details, feet and top plate, but all OK so far.
I need a bake-off now, to listen to to them with decent amplification; my valve power amp is still in pieces, but now I'll get it finished, and the LDR pre shouldn't take long to make.
The crossovers are easy to reach for modification, and there are HF and MF level switches already.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/7e8e502a-11e2-403c-a0e0-2a82118adc3b_zps0bb63014.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/7e8e502a-11e2-403c-a0e0-2a82118adc3b_zps0bb63014.jpg.html)

http://i1134.photobucket.com/albums/m604/awkwardbydesign/JENZEN%20SEAS%20ER/dcad9ac6-4d38-4328-8d29-4c4912ffa7d5_zps9fec303f.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/JENZEN%20SEAS%20ER/dcad9ac6-4d38-4328-8d29-4c4912ffa7d5_zps9fec303f.jpg.html)

[Qwin]

Very nice project, good skills.

:clapclapclap:

[awkwardbydesign]

I just tried to push one back towards the wall. It stayed still and I slid backwards! I weigh 65kg, the speaker weighs 100kg. :lol:

[awkwardbydesign]

I want to try isolating the cabs more, so bought some little springs for the bolts on the back of the HF/MF cabs. They were too weak, but as I have two bolts I could spring both of them. I now need to buy some more for the other side, but they only cost £3.13 for 5! Who knows if it will make a difference? :) Still need to find some bigger springs for the bass cabs.
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/2014-08/20140805_212931_zps0yunadzf.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Mobile%20Uploads/2014-08/20140805_212931_zps0yunadzf.jpg.html)
http://i1134.photobucket.com/albums/m604/awkwardbydesign/Mobile%20Uploads/2014-08/20140805_212857_zpsuwdkqe8q.jpg (http://s1134.photobucket.com/user/awkwardbydesign/media/Mobile%20Uploads/2014-08/20140805_212857_zpsuwdkqe8q.jpg.html)

[awkwardbydesign]

The new yellow springs and some longer bolts arrived today, but not fitted yet. I'll have to try to measure the oscillation frequency, which will be a challenge, as you only get 4 or 5!
I've been merrily trying to calculate the required springs to go under the bass cabs. It makes my head hurt. I need approx. 50mm dia x 75mm long springs, resonating at 2-3Hz with a load of 1500N/m (15kg approx) and 30-40mm deflection at that weight. I get 3.25mm dia. wire, 5 coils (3 active) closed and ground ends, which gives a spring rate of 3.5N/mm. Probably! I have contacted a spring maker to get a quote for 8, but they aren't cheap. I would have to sleeve them with something to damp the resonance, inner tube, heatshrink, socks(?) without changing the frequency too much. And turn top and bottom caps with height adjustment; I have some nylon or Delrin rod, so a nice project for the winter.
If I could afford the Townshend feet I would buy them. But I can't!

[awkwardbydesign]

Well, I've had a quote for 8 springs made to my specs. £80 delivered. I THINK my calculations are correct (and Serge agrees), but it's a fair chunk of cash for me, especially as it is experimental. Maybe I should get another quote.

[slate]

Maybe NORAD have some leftovers http://science.howstuffworks.com/norad2.htm

[awkwardbydesign]

Lol! I'll ask for a price.

[awkwardbydesign]

.

[awkwardbydesign]

Had a bake off today. Speaker cables sorted the wooly bass. Whodathunkit?

[awkwardbydesign]

Just changed the Jantzen MOX resistors (tweeter attenuation) for Mills wirewound. I wish these things didn't make a difference! There is less "edge " to the treble now.

[awkwardbydesign]

Well, over two years on and I think they may be finished, at least soundwise. I have rebuilt the crossovers, up to the NEXT spec, with decent components, and although they have only been running for the last hour, I don't think I can do much more with them. It would take all new drivers improve them, I think, and that won't happen.
I am now starting to build a type 26 valve preamp, having heard one in my own system, so that should keep me busy for a while! I am having to learn how to use simulation programmes, which is totally alien to me.

[awkwardbydesign]

Six years on, and I measured them with REW, and discovered that I needed to tilt them down to get on the mid driver axis, which cured a comb effect dip at crossover. But my wife and I listened to some Quad 2905s, and as she really liked the sound of them, these will be up for sale very soon. At 100kg each they will take some shifting though! At least they separate into two parts.
https://live.staticflickr.com/65535/49000239043_fd904217cd_c.jpg

[oceanobsession]

Hi dick , best wishes with your next purchase , I do like the sound of the electrostatics , ill try tilting the top cab , waiting on a valab phono stage from Taiwan , sounds
wonderfull for cheap money , and im building a passive pre with slagle autoformers and a sieden stepped switch to go with the mng da monoblocs . I had to much wool
in the top cabs i managed to get it out from the back and its made a big difference , best wishes phil.

[awkwardbydesign]

Hi Phil. What were the effects of overstuffing? And how did it change when you removed some? I found similar with the bass cabs, but I had added more and had to remove it. Now they follow the Chris Rodgers Pro 9TL method. Although I haven't added the foam at the mouth at the moment; I will experiment some more with that, but I think it is room dependent.
https://live.staticflickr.com/65535/49008222673_e55bdb2993_c.jpg
https://live.staticflickr.com/65535/49008220553_ec733669b5_c.jpg
This is the thread about the Shackman HB3s I am playing with. About £30 spent so far! https://hifiwigwam.com/forum/topic/133911-electrostatic-hb3s-sort-of/

[awkwardbydesign]

I was measuring the response of these yesterday, in case they needed fine tuning, and the the left speaker had a horrendous response! Big mid peak and hardly any treble. WTF? I swapped tweeters, swapped crossovers, measured amplifier outputs, driver and crossover responses, no improvement. Then discovered the interconnect I was using to feed the signal to the pre-amp was faulty! Grr. All good now, and both channels match. Phew! But the two sides of my room don't, and the room damping I've added absorb a bit too much HF. But the tweeter attenuation is switchable anyway.
https://live.staticflickr.com/65535/49019742342_64d08382be_c.jpg
I'll pad down the mids a little more, with a switch for individual room preferences.

[awkwardbydesign]

Well, they've gone! Six years of work, and a happy new owner. On the same trip to London I bought a pair of Quad 2805s, and guess what? One of them is faulty! Grrr. But I think (and hope) it's an easy fix, a loose dust cover membrane.
These are the first pair of proper (not little cheapo) speakers I have ever bought, in nearly 50 years!
https://live.staticflickr.com/65535/49094866332_fd87f4dffd_c.jpg
With a little work, I can re-use the isolation springs under these. Once they are fixed!

[Audio Al]

Richard are you suffering subsidence :)

[Pigmy Pony]

Richard are you suffering subsidence :)

Yes it wouldn't pass the Malteser test. But it's an easy fix - the black knob on that red panel behind the speaker is for adjusting tilt :)

[awkwardbydesign]

Richard are you suffering subsidence :)

One leg longer than the other.

[Audio Al]

One leg longer than the other.

:D:lol:

[hornucopia]

Two things wrong; one is that your Gravesen speakers weren't 'cheap'....in fact, certainly better than many other/pricey speakers.
The other? You have a partner who actually LIKES Quads!
Rumour has it that the only way to get a wife to grudgingly like Quads was to blindfold her first, let her listen to her favourite tunes on them, THEN remove the blindfold! (-:
Hope the hassles go away soon!

[awkwardbydesign]

Two things wrong; one is that your Gravesen speakers weren't 'cheap'....in fact, certainly better than many other/pricey speakers.
The other? You have a partner who actually LIKES Quads!
Rumour has it that the only way to get a wife to grudgingly like Quads was to blindfold her first, let her listen to her favourite tunes on them, THEN remove the blindfold! (-:
Hope the hassles go away soon!

But I didn't buy the Gravesens; I built them. Like very other pair of main speakers since 1971.