2 DR250 build - Europe Materials

[Marflinger]

After figuring out some Questions upfront, i decided to start the build thread for others to comment and see whatever they feel a need to.

Some results of the questions before starting:

- Handle in the back with angled sunken connectors, connectors for BI-Amping and chaining two cabs (so 4 connectors). Optional passive crossover module could be fitted inside the handle, connected to the input-connector, and leaving a flush connector outside the backpanel.
I will go for bi-amping including passthrough, so i will have four connectors on each cab. Will be slightly bigger to fit everything in, but i will take that for the first build.

Back panel is thicker then needed/recommended in that situation, to have the handle not falling apart when grabbing it/strapping it there.


Wood Quality:
I was going for the Birch Plywood in 12mm as recommended, but the other option is a combination of poplar and eucalyptus, 7 "true" plies, which brings down the cost by a lot.

Wood cutlist:
I can highly recommend www.opticutter.com (limited to 20 different panels in the free version); esp due to the option to export as dxf to further optimize for all CAD-Users. The Link in the plans does lead somewhere into the darkness.
By that optimisation i need one sheet of 4/8 feet (in global units, 2500*1250mm) per cab, and have more then enough spare. By the price of the poplar/eucalyptus, the wood needed per one cab comes down to 72,53€ per cab for the 12mm/half-inch needed.

PU-Glue:
As PL-Premium is not available here (i assume by the chemical components, it would be illegal due to regulations here?) i went for the latest i could find with a reasonable pricing; Soudal PU glue from the supplier collection thread here.
Foams, is available and, compared to other solutions matching that, a cheap variant.

10" Driver:
Very useful database imho: https://loudspeakerdatabase.com/search/ ... %89%A450.0
here added the parameters from the plan to get an overview. Not at all a complete list, but gives you a range.
With maximum output in the low-end (and european availability) in mind i'm on to choose the LaVoce WAF(or WAN)102.50 (slightly out of specs by the Vas below 25l as the WAN as well; link for that specs included: https://loudspeakerdatabase.com/search/ ... %89%A450.0)
The WAN comes with a slightly higher pricing in germany, the question for me is if the specs will have an effect that would be worth it? Weight difference is obvious, but i don't really care about that weight.
WAF has a way higher Xmax? Higher power handling? Lower Fs, that will not be needed, but anyway? Vas closer to ideal? Weight aside, i don't see the benefit of the neo-variant.
My bad, compared to the discontinued WAF102.52.
WAN has the higher power taking of 100W, and increased 1b sensitivity. WAF slightly lower Fs, but not used anyway.
Anyone compared these two in theory (simulation) or used both?

These are my results getting quick prices:

(Total costs for 2 cabs on the right)
Not sure if the price of the driver goes linear with the quality at the end, any tips?

HF-section:
European problem, in the end the piezo-version would be more expensive sadly.
To the monacor-recommendation: There are two available, i assume it is about the model MPT-016 and not the MPT-025?
Needing 20 per box, or 50 in total to sort out the bad ones, that comes in quite expensive at 8,94€ per piece.
Probably i'll end up in the future with a combination of piezo and cd stacked on top of each other, but for the first build i was aiming at the cd version. The ones i can order from here are the 1001 and the LaVoce-Option; not quite sure about the benefits of these compared to each other? PRV would be import-able somewhat, not sure about the final costs then.

Price comparison as well:

Screenshot 2025-12-14 080720.png (9.59 KiB) Viewed 211 times

(Total costs for 2 cabs on the right)
Same as to the LF drivers, any tips?

If it's worth it, I'm more then willing to spend on it...but i can not guess about the real worth vs. the pricing. The better dispersion of the melded piezo array in closer range makes me think about going that way. LF no idea beyond not going the cheapest way.
High SPL and low distortion would be the criteria, weight not that much. Also the final result when playing with subs should give me a kick i can feel...will never be used without subs. Sub yet to choose.


Processing:
For now i aim at active xo, driverack PA2 it is (the wifi-connected remote control is the deciding point and worth the buck for me). Amps not sure yet, for testing i have some hifi-amps that will do the trick.
Cab for now one per channel, chainable in 2 per amp-channel with the first one built the linking one. The Addition will only need inputs; and then there has to be another chain like that for the future if i'm going to extend to 6 or 8 in total.

For now I'll start with the CD version (if not convinced otherwise). When the first pair is done, i'll think about the piezo-variant; maybe as the next extension. In the end having two piezos (bottom) and two CD (top) stacked should have a coverage of all needs, be probably way to much already.
also three or more together should equal in a quite flat response by design. As the LF with 8 ohm would be wired parallel with two cabs result in 4ohm when linked; same goes for the two CD that are wired to give an 8ohm per cab. So each channel will see 8 ohm when bi-amped one cab, and 4 ohm when bi-amped two cabs in parralell. Limiter presets to be set accordingly.
For chaining of a CD and piezo cab i will need to go for xo in the amp, or switch to passive xo inside the cab. Not sure yet, i will see. Probably two CD-units chained, and one piezo with passive xo on a seperate amp?


The plan:
Drivers still to choose, but on monday i think i'll find the time to get the wood and start building the interieur. When the baffle needs the screw-in holes for the LF driver, the driver has to be here...but that is as far as i can go for now.

So any hints on Driver choice will be highly appreciated

Edit: My uneducated guess would be to go for the combination, LaVoce WAN102.50 for maximum output and the HF CD LaVoce DF10.142LK for the lower Crossover option. Maybe I'll just take the risk and get this combination, to gather everything befor the yearly shutdown so I can use that time to hopefully build it. Any errors on that guess i don't see?

[AntonZ]

Many years ago I was also in need of some parts that were either not available or stupid expensive in Europe. I bought a bunch of parts from Leland (long time member here, owner of https://www.speakerhardware.com ). Leland sells the Goldwood 1016 tweeters at $2.98 each. Shipping, customs and VAT add to the bill. Way back when it still worked out cheaper for me.

[Marflinger]

Many years ago I was also in need of some parts that were either not available or stupid expensive in Europe. I bought a bunch of parts from Leland (long time member here, owner of https://www.speakerhardware.com ). Leland sells the Goldwood 1016 tweeters at $2.98 each. Shipping, customs and VAT add to the bill. Way back when it still worked out cheaper for me.

Including shipping i would end at around 250 bucks ordering to here, and as the tax/borderfee is not included in total around 300...
Which would still be cheaper, but the non-availability for replacement in case shit happens (ordering 2 for replacement and have the same shipping costs) somehow kills me.

Plus, in a german manner, i can order the 50 here and just send the worst ten back with no extra cost and refund. So no extras to pay for, and then the gap to order in the us becomes super small...as only 40 to pay for are around 350

And beneath the tweeters, availability seems to be fine?
The LaVoce-drivers didn't seem so bad to me, or are they known for their bad quality? Regarding the text in the plan, they seem to be a very fine solution?

[Marflinger]

Time flew by in a chaotic way, but i got a lot done.
Just forgot about to post, but here we are now:

Got the wood without film or other toppings, found it even a bit cheaper (will do cost sum-up in the end)

I went for the LaVoce-combination mentioned above, so far everything i need arrived.

And then i started cutting, dry-fitting and gluing together; for now i finished the mid-horn (except the flushing of the horn entry and the angled cut on top/bottom), the baffle is cut including all angles and top/bottom is cut and has its markings for the horn path.

Sadly i didn't have as much time as i wanted, and the shop needed some cleaning first (and still needs more, but i wanted to start anyway); for now i spent two half days on everything including the cleaning.

Now for the eyes some pictures, will post more later:
(Waiting at the doctors office right now, more later)

Cut in angle the whole board, to seperate the horn sides from there

Once fully understood, the different angles fit together. That took some errors to get it right.

All parts came together nicely

Clamps and screws to hold it all together while the glue sets. Top/bottom horn mouth bigger to cut flush later. Poplar super easy to handle in that way.

A question came up:

Here temperatures are below freezing, but the glue foams fine so far and even expands without wetting it. Anything to consider about that?

Will later add more pictures and my wiring idea, not sure if i get that right.


All in all i read a f*ckload of information the last days, just as it is mentioned: read it again and again and again will probably answer most of the questions. I needed a bit to fully understand that, now my head is sunken in

I commented the plans for measurments and angles with little sketches at each piece and printed them, very handy now and can only recommend.

[Marflinger]

As for the wiring:

Going for Bi-Amped, and willing to couple two cabs per channel, left me with the following:

All power ratings the RMS-Levels from driver specs.

Four Connectors, LF/HF each in and out.
In/Out for both Bands parallel to each other, so a second cab would lower the impendance as written on the diagram.
No real need for 4-Pole-connectors, but whatever.
Any Errors on that so far?

Amps would have to fit the power of two cabs, with limiters lowered when only one cab per channel. Will have to store presets in the driverack for both variants.

And to the build itself, here are some more pictures, today will hopefully work out to have top/bottom attached and get further on the bracing.

As my tablesaw tilts the table, not the blade, i had to screw the angled pieces for a safe cutting (will fill and sand the holes of course)

baffles cut

All set, super sturdy. Will probably leave the screws and just fill and sand the hats.

On to fill the holes, scrap the squeezed glue (chisel ftw, works like a charm) and then cut the cheeks.

Drivers waiting for their new home, and handles waiting for me to give them the sidepanels to live in.

[Keryn O'Shea]

Good looking build so far man

Four Connectors, LF/HF each in and out.

Is there a reason you're running this way? Would it be more simple to use 4-pole sockets and leads?

Amps would have to fit the power of two cabs, with limiters lowered when only one cab per channel. Will have to store presets in the driverack for both variants.

Here's a thread dedicated to setting limiters,
viewtopic.php?t=8755
(Happy to be corrected here) As l understand, your voltage limit will be the same for 1 or 2 cabs per channel, it's a case of making sure your amp can handle 4 ohms and cover the power your asking for both cabs.

[Marflinger]

Good looking build so far man

Four Connectors, LF/HF each in and out.

Is there a reason you're running this way? Would it be more simple to use 4-pole sockets and leads?

Not sure how you mean that.
One nl4-input with +1/-1 for lf in and +2-2 hf in, just chained to a 4 pole output?
I liked the idea of seperated connectors to not mismatch anything by error...but to have only one connector would be very pleasant in terms of the space needed yeah...

I'll think abou that, thank you for that input.
Amprack would need a patchbay to lead the both amps to the 4pole-socket, but having only one cable would be very neat as well yes.

@limiting: not been there yet, but i assumed it'll change the voltage when impendance is changed. But i'll look into that before i blow something up; my main part was the amp sizing which seems to be correct so far.

Didn't have much time today, but got the cheeks and dry-fit looked beautiful:

[Strange Kevin]

Looking good so far!

I second using 4 pole connectors for bi-amping. Once everything is built, it should be difficult to hookup incorrectly.

Just one cable in, then one to link to the next cab.

Either pre wire a patch panel for the back of your amp rack
Or some short breakout/Y cables you could leave attached to the amps to connect to your long 4 Conductor cables during setup.

Drive rack Voltage limit stays the same for one or 2 cabs in parallel.

[Marflinger]

I'll go for the 4pole-one-cable solution, thank you both for hinting that.

And as well for the limiting, i'll keep that in mind.

For now i only managed to cut some parts and fit the boys to their top/bottom; really like the part where the final dimensions become visible
Now the glue needs some time to set, as its friggin cold here this takes a while...

Together

So it'll never come apart

Handy to get the glue on that end first, and then screwed to the ruler first so fix in place

Halfmoons waiting

Spacer fitting

Drilling through both panels at once came out quite handy

The woofer spacer somehow got too small, but i figured it wouldn't matter probably.
Im just not quite sure about the t-nuts for lf-driver: i could screw through the baffle as well, and place the t-nuts there - or just in the spacer before putting them on the baffle.
Through baffle seems better, but where the horn flares top/bottom meet the baffle, i have no way to get a tnut in there.
So either rotate slightly to get around the horn, or these two go just in the spacer - or all my thoughts are stupid and all go just in the spacer?

[Keryn O'Shea]

For now i only managed to cut some parts and fit the boys to their top/bottom..

Take your time with the build mate.. less stress, more chance to catch things and it shows in the final product.

..really like the part where the final dimensions become visible..

Yes, that's a great moment

..Im just not quite sure about the t-nuts for lf-driver..

In regards to T-nuts, can l ask when you bought your plans? I thought they were dropped in favour of Allen or hex head wood screws. Quite a few people had trouble with them coming loose or binding up.

[Keryn O'Shea]

The woofer spacer somehow got too small..

Which part of the spacer ended up too small?

[Marflinger]

Which part of the spacer ended up too small?

The outside dimension, about 8mm (i think 1/3"?) smaller measured between the parallel edges outside. The driver cutout fits, just the width of the spacer "bar"(?) The woofer presses on is smaller.
not smaller as the driver, so i assumed it would be fine? See picture, still overlaps.

regards to T-nuts, can l ask when you bought your plans? I thought they were dropped in favour of Allen or hex head wood screws. Quite a few people had trouble with them coming loose or binding up.

Yes, tha plan says wood screws, plans are from this year.
Tbh, i don't like the idea of wood screws holding the driver. Limited number of times i can remove and reinstall the driver, the wood will get lazy by time.
We've used that screw-glue to secure against loosening up, worked fine in subwoofers so i assumed it should do the trick again (loctite brand, commonly visible as the blue tip on the screw).

Would you recommend going for the woodscrews? Once the inner horn sides are mounted, this is not changeable anymore. No way to get in there.


I'm not stressing, i try to double-check everything. Just the mismatch of available time i have and waiting it needs to dry before i can touch it again is some sort of felt pressure. But i got other stuff to do, it's not that i'm sitting in front of it and wait for it to dry
But thank you for keeping an eye on me even in that way, i'll keep that in mind to avoid hasting through it

[Keryn O'Shea]

The outside dimension, about 8mm (i think 1/3"?) smaller measured between the parallel edges outside. The driver cutout fits, just the width of the spacer "bar"(?) The woofer presses on is smaller.
not smaller as the driver, so i assumed it would be fine?

Okay, no problem

Tbh, i don't like the idea of wood screws holding the driver. Limited number of times i can remove and reinstall the driver..

With the quality woofer you are fitting, and limiter set, realistically you'll only be cracking the cab open once every few years for maintenance.

..the wood will get lazy by time...

If a screw anchor is stripped, or even snapped off, the woofer can be rotated a few degrees and re-drilled.
No such luxury with T-nuts.. also when using a threadlock compound, all is well at installation, but if we imagine loosening the locked bolt, the T-nut can also rise out of position and spin
Others have tried glueing and using small screws to secure the T-nuts..

Would you recommend going for the woodscrews?

I've had no experience with T-nuts for drivers, l started building after they were dropped. Not a single problem with screws fitted with lockwashers though. Recently opened up my THT which is in use every day for 12 years to check the screws... they just clicked & that's all they needed!

I'm not stressing...
...But thank you for keeping an eye on me even in that way, i'll keep that in mind to avoid hasting through it

Nice

[Bill Fitzmaurice]

If TNuts weren't a problem they'd be recommended. They are a problem. If you spin one getting the bolt out is extremely difficult. Using Loctite makes it almost impossible.

[Marflinger]

Alright, thank you both for the explanation. Woodscrews it will be, problem with nuts vanished

I got the spacer fixed now, as well as the middle cheeks and the horn bracing to the front as well. Now again letting the glue dry to get properly rid of the excess...by that time i filled every visible hole as well, they'll dry in the same time.

Today i brought them in the livingroom to support the drying a bit, will see how long it will take.
Next step would then be the horn sides and the pvc-pipe, will maybe fit into tomorrow.

Some parts for the eyes:

The tilted table, 20° are already wild. But that saw is working fine since around 1960s, love it.

Roughing the front braces to fit

Cheeky view, glue still wet

Braced and strong