Backyard Box Building - The Build

[macaroonie]

Hi all at last I am ready to start building my final solution speakers. These will be a kind of L300 clone. This is a project that I have been fermenting for some time ie. about 25 years. I first heard L300s way back in the 70's and the sound signature stuck with me ever since , like an itch you cant scratch.
I know there are bigger and better monitors but space considerations come into the equation also.
The purpose of this thread is to create a step by step guide to cabinet building using the minimum of tools and shop facilities, in other words the simplest easiest way that anyone with moderate skills can achieve a good result.
My project carries some quirks in that I am going to emulate the L300 cabinet but with different dimensions , hence the rounded corners will require more work than a standard rectangular box, however the build methods remain the same for both.
I would like this thread to remain clear of comments in order that the process is easily followed by anyone who cares to have a go , however I am open to any input along the way.
To that end please post comments and input on the other thread ' Backyard box building ' and quote the relevant page / post number.
I will also be calling on the expertise of the gurus at a later stage but that will come along as the build progresses. Here we go-------

[macaroonie]

This project is to emulate in general the model L300 a JBL classic if ever there was one. To that end I have the following components.

2 JBL 2235H 15" bass drivers
2 JBL 2380A Horn throats
2 B&C DE85ti Mid compression drivers
2 JBL 2405A Uhf ' slot ' tweeters
1 JBL M553 electronic crossover network

Apologies re the B&C compressors but this is Scotland and JBL pro components are not all that thick on the ground and most of the drivers that show up on ebay here have been worked hard. The units I have are brand new and their published response is similar to the JBL 2445 driver. At some time in the future I may make a switch.
The electronic crossover is here for two reasons. One it cost about the same as making a new passive from scratch and two I am a great believer in the dynamics and control afforded by such an arrangement. It relieves the amplifier of the messy business of handling that nasty passive network.
For any newbies here there are many referencies to this kind of arrangement in other parts of the forum archive. Stick with this and all will become apparent.

[macaroonie]

As I said this is the lo tech method . No CAD here sir nope.

[macaroonie]

I told you this was going to be plain Jane. This is a sketch of the general look of the speaker

[macaroonie]

This is the baffle layout. Since I am cramming a quart into a pint pot here the overall size is determined largely by the driver dimensions. I made a bit of a boo boo getting the 2380A throats in that they are somewhat taller than the old conical throat/ lens however the plus is that they extend lower and should integrate better with the bass driver. I will still use the 850 hz crossover point of the original as a starting point although the electronic crossover allows easy tweaking.

[macaroonie]

This is a detail of the top corner that mimics the original L300. Standard box builders can ignore this.

[srm51555]

Hi all at last I am ready to start building my final solution speakers.

Mac, this was a very well documented DIY process, but I have one question. How many speakers have you acquired since finishing your final solution speakers. I look forward to your next build.

[macaroonie]

None actually other than PA related boxes. Having said that the M2 concept intrigues me. I could very easily convert those boxes to M2 stylee by putting in a new baffle , move the bass driver up and maybe carve a M2 wave thingy from wood. It's just a shade on the big side as is although I could do as I suggested to Grumpy.
Pricey over here though when you factor in taxes and shipping.

[grumpy]

what are the dimensions of the flare only ?

ah, without the border... Will have to check the back for mounting, but I'll measure tonight.
If they were cheaper, I wouldn't mind modifying them.

[Pop Alexandra]

Really like the technique of leaving all kinds of indications before the cut.
Useful for both the working team and for working alone.
_____________________________________________
Alexandra from Summerwood