2 DR250 build - Europe Materials -finished-

[Marflinger]

Just a short update, sanding and first layers sprying before duratex ongoing as the weather started being nice enough :)

Soon to be completed.

edit: first layer of finish as well :)

[Marflinger]

The inside finished and drying...In front of a heater due to winter still wintering

Today will be the last coat on the outside as well, as soon as i can flip them over :)

[Marflinger]

\o/

Sadly time still not enough...
Did the wiring of the connectors (to big wires, used a shrinking tube to keep them sep.)

Esp the input is sort of in suspension with 8 wires soldered to it :D

Did burn in the 10", pre-set the driverack...but rest will be the next few days.
Sad - i'd love to hear them now - but glad i came that far at least :)

Will take the time as soon as i can and post the result :)

[Marflinger]

Got the software installed so far, the filler as well as the half-soft-ware; now the interior design is complete except the electric parts :)

One Question before i solder something bullsh*t together:
the dc protection on the hf module, wired in series - in the hot line or the line back? Between the drivers? Does it matter at all?

I mean this situation; my assumption would be (for "protection") befor the CDs in the hot line:

The LP so far clear, as it is in the plans.

[Marflinger]

Hrhr, well yeah :)
So i did it as painted above, put everything inside, and gave it some music to feed on.

Gladly, the trip was worth ist even without eq :D super clean sound, timing already (at least audible) in time and directivity is awesome.
I had to stop cranking it up way before any limits, outside it is raining and in the little room i did not want to risk ear damages :D
But i got what i expected, thank you bill for this and the others for guiding me as well :)

The inside before closing

Both wired and finished.
(First damages in the surface already, and the tape around the hf module did squish the middle a little bit out. will see if this sets over time.

The wiring from the rack also done finished, 4 channels in two cables running fine.
The linking also works as intended, both ways.

Will see when the weather gets dry enough, take them outside and measure it and play around there :))

[Marflinger]

To the wiring inside the handle:

Works as planned; the handling of the connector super easy (even a bit smaller would be possible, but smaller the handle is no more grab-able by my slightly oversized hands)

Happy with that solution :) Will add that to the next pair as well. But the next will be only one 4pole connector i guess

[Marflinger]

Some of the conclusions from the building process, just for the quiet reader (as i was) to maybe avoid some errors...

The plans, get deep into them before you start. The sketchup file is essential part of the plan, i first did not get this.

As i was not used to the PU-Glue, this material differs. Super smeary, and the expansion comes with a force. think about the fixing process before gluing. My way of screwing worked fine, clamping can be a pita on the angled/bent parts...
(Sidenote to the glue, stains can be easily removed with oil as every resin based stuff)

I usually go by not as precise as possible, just as precise as needed. Maybe should have done some stuff more precise, there are thoughts to every dimension given.

All these angles are not that easy to combine, should have done some parts slower maybe.

You will need way more hot glue than i imagined to have in my hands (ever). But it works, i just had to get used to it at first.

The next build i will do a inner skeleton ruler for alligning things, way more simple and leads to way more identical cabs. I now have it quite similar, around 2mm differences in it, but it takes a lot of re-measuring. As i can print in scale i will do some routing and alligning rulers for the next pair. Would have done them for the first as well if i had known the benefit. Will post them when done.

In general not a build to start with woodworking, can not recommend. Know your tools, know how to handle them - or hell is gonna break loose on you^^

The concept is really doable, all the steps try to secure out any errors and make it possible without any fancy tools. Fancy tools make it a little bit smoother, but it works with a circular saw, a drill, a sander and a router. Can highly recommend a stationary sander for the little parts.

I took way to thick cables, not needed and make the soldering to the sockets a nightmare. But on the XO-Part, softening the cable with a lighter and you can just shove the wire of the parts inside the bigger wire and solder the end; very smooth solution. Not sure if i would repeat that wire tho. Took 2,5mm² i had handy.


Without errors, you can get two DR250s out of 2 sheets of ply (125*250cm, i think 4 by 8 foot), one meter of pipe (DN110 HT) and half a sheet of the thinner plywood for the bent parts.
I opened the third tube of glue while finishing, when using it more carefully probably two would have been enough.
The extra handles/Connector and extended back ate some of that glue as well.

Edit: the time consumption also a thing; i did a used new rack within the same time, but including that i think i got around 90 hours in total, so maybe 75 without the rack part...not sure if that matters to anyone, i thought it could be interesting.


As i dont care about the optics, surface quality is not that high on these two. But it is really doable, just filling and sanding more. I just wanted to have them dark to be not that present, and protect the wood surface. Did one spraypaint-layer (go for the graffitti-spraypaint as this covers way better, and is even cheaper) and then two coats of warnex (=duratex). This is super forgiving material, use it. Had 1kg, used around 2/3 of it for both cabs total inside and outside. I took a brush, will try how spraying does it on the next cabs.

Yeah the acoustical result feels super nice, as soon as the weather is not that wet anymore i will drive them to the limits and measure some things. But for me it feels like it was def worth the hassle :))

Thank you again for sharing the plans with the world :)

[T_Gowan]

Both Thumbs up on this build, great job and thoughtful points at the end.

[Tom Smit]

+1

[Marflinger]

Noticed the first f*ckup :D one of the 8-wire-connectors got loose, probably not properly done by me due to space issues.

After fishing the lost cable out there, i got a new solution with a piece of solid wire as a spacer.
But conclusion from this trip: go and make all the wires to one bound pack some space beyond the connector, to avoid loosing one behind the little hole...

[Marflinger]

Sooo, i did a thing or two :]

Still no option outside, but as i had to clean the shop anyway i placed them there and played around a bit :)

They need/want to get some EQing to sound even better, but i got them :)

The amp i power them with has its own voltage limiter, i set them according to the drivers specs but i never came close to the limiter activating.

This is how the limiter looks like in the amp interface, it is a wharfedale DP4065F. Would be enough power to have 4 DRS on it, 2 channel for midrange and two for the HF-region.
Seperation is done in the driverack, limiter is the only fancy part of the wharfedale i use.

Then i did some measurements "naked"; shows a wild curve and especially a deep dive around 1,2 khz:

This was naked spl and phase (no calibrated mic, and no calibrated spl. Leveled with SPL app on my phone)
I tried around a lot, also with the crossover placement and how steep it could be. And i added 4 bands in the EQ in the driverack to correct the curve a bit:

The smoothest so far (got louder in between yes); XO set at 1,7 KHz now. seemed audible the finest point, when i can drive them outside i will optimize that further.

Low cut is now at 100Hz as i want to use them with subs; just wanted to see how it feels down there.
Yeah probably works for some applications w/o subs; not for me. But as a top, sounds fine :)
And then i thought i could try to poke the limiter.
Well, no i do not want this. the output is kind of obscene; i did not want to reach to the limit. Especially when in the same room and not really a place to hide :D
But interesting yeah, sounds good as far as i pushed it.
Took the HF section 2db lower, to have it a bit easy on my ears, and listened to different styles of music...all of them went well through there, i like it :)

When i can go out and do real measurements, i will add them here for completion :)

[Bill Fitzmaurice]

Try reversing the polarity of the tweeters, that may fix the dip.

[Marflinger]

Try reversing the polarity of the tweeters, that may fix the dip.

In the first view, the tweeters were crossed at 2khz; but in the last shot they are inverted yes, this helped.