DR200s for 12volt system

[Mishkin]

I'm finally ready to build a pair of DR200s to accompany my 30" Titan48 which i'm running in a 12volt system out the side of a small van.

The 2x12" loaded, 2ohm sub is built but not yet tested - that'll be on the to-do list for this week.
The 2 x12volt amps, wiring, and DaytonDSP 408 are ready and in place in the van - although DSP obviously not dialled in yet.
Ive sublet a little bench space in a very damp studenty wood working space for a few weeks and excited for the challenge.

I'll be building the dr200s out of light weight Italian Poplar ply sheets - called Poplar Garnica - each sheet costs less than half the price of a sheet of Baltic Birch where i'm based in Glasgow, Scotland. The 7 plys look decent although a carpenter friend warns me the poplar is soft and edges wont hold as well as the BB's. He also said that this ply is less weather resistant. Seth suggested a couple of coats of fibreglass resin before i paint the boxes, which i should probably do as they will be being used outdoors.

Im calling in a favour from another friend and he will CNC the 12mm pieces on Tuesday if all goes to plan.

As many before me, I've already been contemplating the problem that all the reputable piezos are absurdly over priced here/ in all of Europe. After toying with the idea of testing out some less reported-on alternative piezos - i've subsequently read too many bad accounts of these online. Im now considering buying the DR200 kit with piezos from Leland at Speaker Hardware (who has already been very helpful), but that will of course mean waiting, and facing the shipping costs and potential customs charges.

I'm sure I'll have many questions along the way. Here are my first few; As i've never bought anything from the USA before I was wondering if anyone on here has experience with getting stuff shipped from Speaker Hardware to the UK? what was the wait time like? and what percentage did you have to pay in customs charges? - A brief internet search suggests that customs charges are inconsistently applied and if i'm lucky I may not have to pay anything at all.

Anyone got some experience on the issue >?


If, it seems too much hassle to buy stuff from The States and alternatively I end up building the double CD version of these - I remember Bruce saying in another discussion that he preferred them crossed over at 1.2kHz (I think this was about Omnitops or another cab). There is no mention of this way of doing it in the DR200 plans. Is this a possible option with DR200s or not?


I will let you know how the CNC goes -with some pictures next week

Thanks in advance,

Kairos

[Mishkin]

Its not the DR200s , but here's some of the finishing touches going onto the T48.

The Rat12 system has a name! ... and a design - maybe that will give me some impetus to finish it !

[Seth]

Seth suggested a couple of coats of fibreglass resin before i paint the boxes, which i should probably do as they will be being used outdoors.

It's a thought I had. I haven't tried it. It may be worth verifying whatever finish coat you want to use will adhere well to the resin prior to committing to it. I think I'd thin it down, so it soaks in a little more and toughens up the wood versus a hardened outer layer. I'll do a little research and see if coatings like DuraTex adhere well to fiberglass or not in a few days. Who knows, it may not even be necessary. You may just have to judge for yourself and make the call.

Im calling in a favour from another friend and he will CNC the 12mm pieces on Tuesday if all goes to plan.

Is this a go? If so good luck

If... ...I end up building the double CD version of these - I remember Bruce saying in another discussion that he preferred them crossed over at 1.2kHz (I think this was about Omnitops or another cab). There is no mention of this way of doing it in the DR200 plans. Is this a possible option with DR200s or not?

Bill, will the DR200 CD horn design itself support a 1.2kHz crossover frequency? If the appropriate driver fits within the cab, is the horn length and mouth area enough? Or, is it better to just stick with drivers and crossovers per the plans?

[Bill Fitzmaurice]

The horn may work, but drivers that go to 1.2kHz small enough to fit are rare.

[Mishkin]

Is this a go? If so good luck

Thanks Seth
CnC got done this eve after work ... thanks very much M!

On a first impression, the pieces look really good , The garnica poplar cut well on their machine apparently, and the operator said there was no knots or imperfections in it . The stuff is very light!
having the shapes precut is gonna make my life so much easier (feel like ive cheated) ... still have to add the angle cuts onto a few bits along the way .

The horn may work, but drivers that go to 1.2kHz small enough to fit are rare.

ok good to know, I actually wont' be getting into this line of enquiry because i've opted for the American Piezos and ordered Dr200 Kits from Speaker Hardware . I'm all about making life easier for myself this eve

[Fastskiguy]

having the shapes precut is gonna make my life so much easier (feel like ive cheated) ...

Oh most definitely you have cheated. Well done, Sir!

Joe

[Mishkin]

Hello all

I wonder if anyone could shed any light on whats going on with speaker hardware. com at the moment ?

I was in communication with Leland about buying 2 DR200 kits to be sent to the UK - minus the woofers. He told me to put the order through on the website and as its a bespoke version of the kit i would pay afterwards via an email communication. That was 12 days ago, since then i've not heard from him in-spite of asking via email regularly. I hope everything is ok ?

Can anyone advise if theres anywhere else to make a single order of quality piezos, the crossover components and Bill's proprietary parts for the DR200? - has to be a supplier willing to ship to the UK. I can order from parts express, but couldn't find the DR200 propietary parts there ( phase plug and curved plastic )

Thanks in advance,

Kairos

[Mishkin]

The build is coming along, and i'm enjoying it in all the spare time i can get :

BUT I am having problems getting ply that will bend to the tight radius of the rear curve... The first stuff i got was trash - this is what numerous bits of it look like now :

The only 3mm poplar or birch available to me is supplied in small sheets online and expensive - luckily the guy laser cutting and selling it is helpful and knowledgeable - He says it will not bend to the required 4 and 11/16" radius . he said if done un-steamed it will max a radius of 12 inches

There are three options in my head, which , or what else would you guys advise:

1. Get him to laser cut lines 1 mm deep along the bending axis of one side of the poplar and hope that and curling it up and lettig it creep as advised helps it reach the smaller radius bend

2. find some 3mm plastic of some kind, maybe perspex ? does that bend better ?

3. OR buy 2 times the amount of 1.5mm birch ply - and do it in two layers one after the other , screwed and glued together with trad wood working glue ?


any thoughts appreciated !

Kairos

[Bill Fitzmaurice]

I did mine with 3mm Baltic Birch. There's also bending plywood, which has the grain of all three plies oriented in the same direction.

[Mishkin]

I couldnt source any "flexi" or "bending" ply in time and as the supplier i was talking to was so insistent that his 3mm Birch or poplar wouldn't make the bend. I went for two layers of 1.5 mm birch per bend.

The 1.5mm i got is of a very good quality and much cheaper than buying the small pieces of 3mm online. Timber merchants here do stock 1.5mm ply sheets but not 3mm. buying enough for doubling it up was still less than half the price of buying the birch in 3mm online in smaller pieces.

The good thing about doing it this way was no need to pre-bend and no need to strap it down. staple gun staples into the braces was enough to hold it in place while gluing, and i used small squares of the stuff to space it out correctly in the tight bit where all four meet - taking one spacer out each time a section of 1.5 went in. The down side was the tedious repetition of doing it 4 times per cab rather than 2. i used PU for the first layer and pva for the second. except for in the tight crevice where i put some PU between all 4 sheets to ensure an air tight butt crack

[Mishkin]

Piezzo time... better late then never .. im working against the clock , these speakers are meant to be for their first outing on friday night to an audience of about 100 peope :/

i cut them before testing which wasnt the smartest...

Just finished testing now with pink noise on the goldwood variety... none had reversed polarity ... none were much quieter to my ear ... but there was someone else banging about the workshop occasionally ...
BUT about 8 of my 32 where audibly higher or lower pitched in what they were playing - when i got the analyser on them the higher pitched ones were a db or 2 quieter than the average and the lower pitch ones where a db or 2 louder .... 8 is more than i have spare, im gonna use these ones for now and try and match them in pairs ...

does anyone think that i should switch them out at some later date ?

[Bill Fitzmaurice]

Since they seem to average out with respect to frequency and SPL and you have so many of them in the array I'd leave well enough alone.
Whatever you do make sure you wring everything out before using them in public.

[Mishkin]

Good news about the piezos .

By wring out , do you mean play loud?

if so for how long ? or do you mean just to make sure its all working and sounding good?

[Bill Fitzmaurice]

I mean do a thorough testing of the complete system. The consequences if you don't can be severe.

[AntonZ]

i used PU for the first layer and pva for the second. except for in the tight crevice where i put some PU between all 4 sheets to ensure an air tight butt crack

Yeah, you don't want them to fart out right there. Sorry, could not resist.
Well done, good thinking on the 1.5mm ply and also on using PU in most places, PVA in places where the expanding nature of PU would not be welcome. Nice work!