Troels Gravesens Jenzen D mk2 Speakers - Finished :D

[Green Wagon]

I've previously built Troels SP95's and his Ekta's (still have the Ekta's) and like the way he voices his designs.

I wanted more, as you do, and then Troels released his Jenzen D design.

I roughly priced the parts. HOW MUCH ????

A job with lots of overtime helped fund the coming insanity.

Parts started being ordered, bank started screaming in agony, yet I just kept ordering more and more parts.

 

The tweeters are the center piece. (See my avatar for a pic of it's dome)

Advertised as being 'Diamond', they are actually a "1" pure diamond dome tweeter, dome made of CVD diamond (Chemical Vapour Deposition)"

 

I know some will want to know how much. To save you the embarrassment of having to ask. This is roughly what I spent.

 

Drivers - $6,700 (Jantzen tweeters $4,000/accuton mids $900/audio technology bass $1,800)

Crossovers - $1,200 (Jantzen)

Internal wiring - $1,200 (Harmonic tech 40 feet black, 40 feet red)

Binding posts - $500 (Mundorf gold plated special order through madisound)

Veneer - $660 (Quilted Bubinga, paper backed, two sheets 1300x2500)

Timber with cnc work - $380 (Two sheets 25mm hmr mdf 1200x2400)

4 litres varnish, 4 black rattle cans, glue, felt, inner bonding, contact, stainless bolts, 'T' nuts, etc and so forth sundries ? $500 ?

 

TOTAL ~ give or take $12,000

 

Oh yes, they weight 62kg each.

 

Shortly after all the parts arrived I organized a cabinet maker and had timber and veneer delivered straight to him.

He told me it'd only take 2 months.

Then I was injured at work and fired (Coincidence, You decide  )

Months rolled past with no sign of the cabinets, after 9 months I canceled him, picked up the veneer, and back to square 2 we go.

 

I discovered my timber supplier could get cnc work done. Too within 0.5mm at that.

Suddenly being one of the 'plenty of free time/short on income' this seemed like good timing.

Redid the plans a little to make them more 'idiot assembly' friendly, sent that to the timber supplier, and less than a week later I had lots of bits of timber.

Still had to route holes in the front panel and internal braces, but the basics were there.

Yes, mistakes were made here and there, but I took it on knowing I would make them, and that I also had the time to fix the mistakes.

The front panel was done with a panel saw, hand plane, chisel and sanding block.

Finished with a coat of varnish to seal it before I used car bog to fill 'mistakes' etc, then a guide coat of black as a final check.

 

Due to the injury I can only manage short amounts of physical work at a time.

About an hour a day is all I can manage without incurring the wrath of the pain gods for the following week.

 

The veneer is 'Quilted Bubinga'. Such a hard timber, I had to use a belt sander before final hand sanding.

The 8 coats of 'wipe on poly' just wasn't 'filling' the grain, so I then upped the ante with another 6 coats of brush on varnish.

Slowly they took shape. They have taken me about 8 months under my own steam.

 

Finally, last night I finished them with Mothers cut #1 and then Mothers synthetic polish.

 

Enough already I hear you scream, how do they sound ?

The overall sound to me is clean, clear, plenty of bass and impact when it's called for.

And the 'girls best friend' diamond tweeter, it just doesn't exist, the treble just appears.

 

Some here have heard them, more will (Msg me, See if I can accommodate you ) So I'll let them give there opinions in this thread if they wish.

 

Personal thanks go to;

Ringwood and ply at Oxley for suppling the cnc'd timber.

Steven from Speaker bug in Milton for sourcing and supplying the drivers, crossover parts and ports.

Phill G   for his help in veneering (Actually he did most of that, I'm somewhat limited these days).

 

To the pics.........

 

Just back from Ringwood and ply.

 

The cnc work, um, plus some of my own routing. doesn't help I asked for 4 lefts instead of two left, two right, Doh.

 

Progress, gluing in the braces. Everything interlocks.

 

Open shell, no front panel.

 

I know some hate 'T' nuts, but drill tiny 'guide holes' for the prongs before gluing them in, and never look back.

 

Yes that really is $1,200 worth of cable. (for the red and black combined)

 

Felt and cabling installed.

 

Tweeters.

 

Ceramic mids.

 

10" bass driver. Solid and heavy. about 9kg each.

 

Bass crossover installed inside cabinet on the back wall just below the terminals.

 

Cables passing through bottom plate for the mid - tweeter crossover.

 

Finished mid - tweeter crossover.

 

Screw on the foot.

 

Sexy gold plated solid copper terminals.

 

Ohhh shiny.

 

And, at long last, the finished speaker. (Yes there are two of them, but I can show it better this way).

 

One is the loneliest number......

 

 

EDIT,

And to those that don't think they can do this, remember, I do NOT have any sort of workshop, shed, or garage.

This has all been done with basic hand tools, inside a spare room, and outside on a paved area with no shelter.

 

EDIT - 13-4-2014 - seems to be some interest in the front panel construction, so heres some pics of this process..

 

Just two pieces of mdf cut to size, had to cut the holes and rebates before the next steps.

 

Midrange step glued and screwed to main baffle. (4 screws from behind). 

 

As you can see, I'm not a cabinet maker, but with time I got decent results.

 

Starting to shape the baffle with a hand saw, chisel and hand plane.

 

Lots of guide lines and some patience.

 

On the 'correct' originals this is flat, on mine due to my changes there very slightly curved.

 

Using car 'bog' to fill mistakes and gouges before a coat of varnish to seal and lock it together.

 

After a quick spray (rattle can) as a guide to show me what I need to correct. (Yes there was a few bits here and there, but impossible to see in this photo).

 

>>>>>>>

Edited April 13, 2014 by green wagon

[henry218]

congratulations green wagon, cool build , blin$ blin$

love to hear them sometime

cheers

Henry

[Green Wagon]

Henry, just message me when you think you might be up this way, and we'll take it from there

 

Forgot to mention, I'm in brisbane.

Because of the room size, (smallish), it'd be easiest to have small 'gatherings' of only a few at a time.

This also gives people a better chance of hearing what they want.

 

At least thats my thoughts

[peterpan]

awesome build and top drivers, well done

 

I follow Troels diy stuff and would love to build some of his stuff.

 

thanks for the photos and info

[henry218]

Henry, just message me when you think you might be up this way, and we'll take it from there

Forgot to mention, I'm in brisbane.

Because of the room size, (smallish), it'd be easiest to have small 'gatherings' of only a few at a time.

This also gives people a better chance of hearing what they want.

At least thats my thoughts

thanks mate, will do

[teagle]

Look magnificent, hopefully will have sound to match Despite being in relatively good health I wouldn't be able to do such a standout job. Congratulations

[Green Wagon]

Look magnificent, hopefully will have sound to match Despite being in relatively good health I wouldn't be able to do such a standout job. Congratulations

 

 

Why thank you.

I think they sound awesome, but of course I would

Photos can hide a lot of problems.

If you have a plan, and slowly do it little by little, You might be suprised at what you can do.

Having said that, I have met some absolute clutses that I wouldn't trust with oxygen.

 

All I did was do one bit, then fix whatever problems I created, before moving onto the next drama

And yes, I did make a few mistakes, but I managed to overcome them all.

 

My biggest problem was pain, money, and sometimes just outright motivation.

But by being able to just walk away from them until I felt like I wanted to work on them I think was the biggest thing that kept me going.

[Pete S]

Great work!

 

Would you say the Jenzen D is leagues ahead of the other Troels Gravesen designs you have built? Currently having some Ekta Grande's built in a similar fashion with all the best components etc. Not sure what to expect from a DIY design, but have heard only good reports!

[Green Wagon]

The SP95 although a great speaker for what it is, once you've heard a well done 3 way, you will notice that little something missing in the midrange.

The Ekta, is an awesome speaker, very very musical and does nothing wrong. Took mine to a gtg ages ago and from what I gather others were amazed at their performance.

 

I have access to a pair of 4333 JBL clones (all original JBL 16ohm pro drivers, pro version of the L300), compared to the Ektas, the only difference the owner can hear is the bass on ektas goes a touch deeper.

I can also hear a slight difference in the treble. But it is an amazing close match.

 

Now, the Jenzen D, it is another class of sound, much tighter and cleaner sounding, deeper bass with more impact.

I had these running in temporary thrown together boxes not long ago, and if you don't believe in driver break in, these will change your mind.

On initial listening I was very, underwhelmed, by their sound. But this changed within the first few hours. Both midrange and bass changed dramatically.

 

The treble, the D's are more, airy ? seem to go further cleaner and lighter.

Midrange is cleaner, not as warm as the Ekta's.

Bass goes a little deeper (but I suspect this is more music dependent and expect the D's could go deeper than what my music calls for).

The big change for the bass is the speed (bad word). I think I'd have to say the audio tech bass driver has much faster transient response.

On paper they have much lower distortion, I believe it shows in the sound.

 

if your considering the change from Ekta grand to Jenzen D, I think I'd call it more of a step up with a jump sideways.

 

If you prefer a cleaner more neutral sound, Go for it. But I'd suggest trying the 'Accu' version with the ceramic tweeter.

that one change will save you around $3,500.

 

If you like what you hear and want more, swap the tweeter and do a small change to the crossover.

 

What I might do, is get some visitors to compare my Ektas with the D's and let them report their findings here..

 

Mmmmmm, do I dare suggest that at that sort of price you could consider his ATS4 ..

The money you save on the diamond tweeter would pay for the extra driver and crossover parts easily..

 

Maybe hitch a lift with 'Henry218' and come have a listen..

[Sparkle]

Hi Green Wagon, What  fabulous looking speakers, they certainly don't look like a Diy job. At risk of being presumptuous, I would love to have a listen!

[steve u]

Congrats, persistence obviously pays off, terrific looking speakers.

 

Being a fellow Brisbane dweller and also presumptuous, I too would love to come and have a listen.

 

You almost make this type of build sound easy, obviously experience counts.

 

Cheers,

Steve

[hochopeper]

Great looking result Green Wagon! If there is a mini GTG I'd love to have a listen

[Green Wagon]

Sparkle, steve u, and hochopeper, msgs sent...

 

basically i try to stay down my end of the house, and without furniture shuffles, the room there in is a smallish bedroom, just over 3 mtrs square.

more than 3 people makes it rather cosy, so I'm aiming for one on ones.

I've measured the room and its actually pretty decent for sound as it stands now.

 

also means no one can complain about your musical tastes

 

 

EDIT. trying some different speaker cables. Awwwwwwwwww hell yeah, next on my shopping list 

 

EDIT 2. forgot to say, I've sorted all the pics I have, so if anyone wants more construction pics, I can oblige now..

Edited April 8, 2014 by green wagon

[niss_man]

Very very nice build green wagon. Better than a bought one. I might have to ask Phil for help veneering one day as well. (his workshop is definitely not short of a clamp or 50)

[Green Wagon]

Very very nice build green wagon. Better than a bought one. I might have to ask Phil for help veneering one day as well. (his workshop is definitely not short of a clamp or 50)

 

 

I'm flattered by all the praise, but I'm tempered by the fact that photos can hide lots of problems..

But I will let those that visit add their 2.2 cents worth.

 

The veneering was the easiest part of the job i think.

We didn't use a single clamp.

but the way I'd constructed them made it a touch harder to veneer.

 

I designed (and had cnc'd) the front panel 1mm wider than the box all round.

The idea was to construct the carcass (then glue in felt and install cabling), make the front panel, attach the front to the carcass, then push the veneer up against the overlapping front panel.

finally, the front was sanded flush with the sides to make the whole look like a single surface.

 

I would like to say to those that do see and hear them in the flesh, please report here your thoughts on them.

If you don't like them, or find something not right, I want you to say so, be honest, it is how we all evolve and it might help others decide if these are a design they want to pursue themselves.

 

And OMG, these speaker cables I'm trying at the moment

 

I have never loved Colin Hey this much before.

The temptation to turn the volume up higher than I should is almost overwhelming...

[steve u]

I jumped in my little white wagon today and drove over to Green Wagon's today to listen to his speakers.

We first listened to the Ekta's and they still sound impressive for a 10 year old build. But, the Jenzen D's....

 

First there was only one Jenzen playing with the right hand Ekta and the sound just grew and became bigger and like green wagon's speaker build just became more beautiful.

 

While one sounded good, two obviously sounded better and the sound really was beautiful. Everything became bigger, tighter, sweeter and whatever other way you want to describe these speakers were special. Green wagon has spent the dollars and taken the time with his project and has been rewarded by a very, very good pair of speakers.

 

Thank you for letting me listen and for taking the time to explain the process and I think you have inspired me to give something, maybe not this grand, a go in the future.

 

Great speakers.

 

Cheers,

Steve

[Green Wagon]

Hey Steve, your more than welcome to come over and have another listen anytime.

Maybe I'll remember my manners next time and offer some refreshments. oops, my bad..

 

Just checked the photo date stamps, I finished the Ektas 6-2006, so there now 8 years old. Not far of my guess of 10 years..

 

I'm starting to think maybe i should build a second set of Jenzen D's and hire them out  :o

[Sparkle]

I'm planning to listen to these speakers on Sunday. It seems we are already of to a great start! can't wait!

[Sierra]

Fantastic build green wagon ... brilliant job!

All your hard work has been rewarded with an outstanding speaker that you will enjoy for many years to come.

While I was builing my DTQWT speakers I spent many hours on Troels website and had a look at a number of his other designs including these.

I thought to myself geez these things have got rather complicated cabinets with all the internal bracing and enclosures ... LOL

Getting all the panels CNC cut and milled make for a much easier and more accurate assy especially for those of us with limited wood working skills ... good call doing that.

Wow ... didn't realise the drivers were so expensive ... $4000 just for the tweeters ... damn!

Crossovers are also expensive ... to be expected though given the number of good quality components involved.

And you've obviously spared no expense on the other components like internal wiring and binding posts etc.

I would have thought that all the raw materials and CNC cutting of the cabinets would have cost more than they did ... very reasonable costs there.

Although the scary thing is that just your tweeters cost more than what my entire speakers cost me!!

Love your attention to detail on your crossover layout ... lovely neat bends on component leads and wiring and on the wax coil copper leads ... very impressive.

Have you got any macro photos of how you soldered the heavy Harmonic tech speaker cables to the smaller crossover components?

Did you source the threaded bolt inserts you've used on the base localy or from overseas?

They are different to the ones I used and look to have a hex drive rather than a slotted drive.

The quilted Bubinga is such an amazing looking timber finish and the contrast between it and the black front baffle and base just looks sensational ... very, very classy!

A beautiful looking (and obviously sounding) speaker green wagon ... you should be very proud of what you have created!

[Sparkle]

Just got back from having a listen. These are certainly professionally finished DIY speakers.

The timber veneer is amazing. looks much better in real life than in the photos.

We probably asked too many questions, so in the end only ended up listening to 4 or 5 songs.

Probably effortless and smoothness would be the best too words that come to mind. These are quite a large speaker and are begging to be played in a larger room with more space behind them.

These would be the most impressive Diy speakers i have seen/ heard so far!

[Green Wagon]

Heya Sierra.

Ta for the kind words.

Having worked on them for so long, its almost 'not real' when you've finished.

 

The original design is fairly complex.

I simplified it greatly by making it a 'one' box construction.

The front isn't sloped, and the bass section is pretty much yanked from his other ported designs that use the AT bass driver.

 

The cnc saved a lot of time, and gave a finish that I have no doubt I can't achieve.

IF I had a workshop, where I could secure parts being worked on, actually, no, I still couldn't get the 0.1mm accuracy of the cnc.

 

I realise my limits, and try to work within them.

 

The crossovers, I saw someones build somewhere (don't remember where) but it was immaculate. Even though no one will ever see it, I wanted it to look like a piece of german engineering.

It's almost a fluke that it came out as neat as it did. I think separating the bass section onto its own board made it easier as it gave me more room to work.

The wires to the cabinet side are all soldered onto tagstrip.

 

Trying to get decent t nuts and inserts in australia defeated me. I want to support locals, but after weeks of searching, phone calls, emails, I gave up.

I bought all those from the uk (ebay).

And yes, the inserts are a hex drive.

 

They just keep rewarding me every day.

What I spent. Hearing what they do when others try there music, at all volume levels, and so far those that have heard them seem to be rather impressed.

To better them I suspect I would have to dig extremely deep into a magical money tree that is now extinct.

 

 

The pics in the first post are shrunk to 30%, the following ones are shrunk to 50%. If you really want, I can post some 100% pics.

 

The inserts.

 

Incomplete crossovers. placement worked out, parts glued down (liquid nails).

 

Crossovers almost ready (had to drill the cable holes).

 

Best shot ive got of the wires soldered on.

The cable looks big (about 8 gauge in size) but it's made up of 8 separate single strands, so once all the insulation is stripped off, its closer to being about a 2.5mm sq cable.

 

Edit. mm, tried uploading a 100% pic the above pic, and the site resizes it to the same size.

 

 

Sparkle, it was a pleasure having you and your friend over.

As men, there is no such thing as to many questions.

Yes, they do really want to be 'let of the leash' in a bigger room.

If you have more questions, please, by all means ask, I will try to answer them as best I can.

Hope your wife didn't kill the credit card..........

Edited April 13, 2014 by green wagon

[niss_man]

Lovely job Nigel and they do sound fantastic. Thanks for the listen.

[wikeeboy]

Spectacular job

[Dave Tomic Henry]

Indeed spectacular. Congrats on the completion!

[Green Wagon]

Simon, Thank you. And your more than welcome.

Feel free to come over any time.

 

wikeeboy and atomictheory also thanks.

 

Now that the varnish has had a chance to degas, I can see that at some stage I will have to give the cabinets another sand and yet more varnish.

I can see little bits of grain 'dimples' all over.

Not quite the perfect 'piano' type finish I wanted.

 

I think the drivers have broken in now, and I think their maybe a little smoother overall.

I certainly don't see myself wanting to replace them any time soon.

Actually, I have investigated a rebuild with a 12 or 15 driver instead of the 10.

Buuuuuuuuuuuut it doesn't seem feasible.

Guess I just have to be happy with these

 

Seems no matter what you have, you always want more.......

Edited February 6, 2015 by Green Wagon