L300 Project Help Reqd. Whisky prize

[macaroonie]

Well here we go.... My next project and probably the last is to be L300 based.
Now here are the tricky bits. I cannot accommodate a full sized version just too big. My plan is to build something altogether neater but with 300 styling ie. glass top , horizontal veneer rounded corners etc. I,m not so sure about the sloping baffle although I might be persuaded.
I have the following components at present;
2235h
2380a throats
no driver
2405
no xover
bx63
I bought the throats for the silly reason that i think they look swell and the slot entry to the flare echos the slot on the 2405. i know they get some bad press but i reasoned that JBL would not have made them if they were truly crap. Yes I know they are 2" entry.
I have yet to score some drivers and of course i now discover that 24xx units go for lots of dosh and are huge. What i do have is a pair of Tannoy magnet assemblies that can be made to fit the 2380.This is the lowest cost option but may not be the best.
I would like to pick the brains of you very learned people. It is clear that your collected endeavours in conjunction with the platform afforded by this forum has resulted in a goldmine of experience and knowledge.
Cabinet dimensions will be in the range of 36" h 18.5" w 15" d the woodwork is not a problem.
The questions in a general sense are crossover - do i start with n300 and work up from there. I can build X/o just cant design them. Can the bx 63 be brought into play to help the bass driver in the small cab. What about loading. I don't have any computer tools and I know some of you guys can do this in a heartbeat.
Bear in mind that Pro components are not ten a penny here.
I guess that is probably enough to get started so now on to the good bit----
As an incentive I am putting up as a ' prize ' a bottle of very nice Scottish Malt Whisky. This will be awarded to the most complete solution and will be delivered to your door worldwide.
Thanks in advance for the fountain of knowledge.

[spkrman57]

Then use a Smith horn with a 1" driver between the 10" midbass and the Smith horn!

Ron

[macaroonie]

The cabinet dimensions are pretty much cast in stone. I want everything in one cab and the width is about as narrow as can accept the 2380.

[Zilch]

I calculate you have 4.6 cuft gross internal volume to work with.

Your system is covered in this thread:

http://audioheritage.org/vbulletin/s...ghlight=keeper

Here's my current implementation of it:

[macaroonie]

Thanks Zilch that post will take a little digesting. I have no experience of the 2450 driver. Better than prev series ? what diaphragm ? Here is a very general layout of my project. I will of course have some blue cloth on the grilles. mac

[Zilch]

I have no experience of the 2450 driver. Better than prev series ? what diaphragm ?

Your design looks quite nice. Consider four smaller ports to allow the drivers to be vertical-in-line, maybe.

2450 is a neodymium-magnet 2" exit large format driver. I put "SL" Aquaplas'd titanium diaphragms in them; they can be purchased that way. You're going to need a bit more depth to make those fit, I think. The requisite depth would be 14.5" from front of baffle to inside of rear panel, 1/2" more if you're going to recess the horn flange flush on the front. Adding 1" depth to your design will also get you 0.34 cuft more volume, according to my calcs.

I have not yet gotten around to finishing up the 2405H UHF version of the "Keeper" crossover. Recommended practice is to cross at 10 kHz rather than the 7 kHz I'm presently using with 2407H. I am confident it can be accomplished successfully, tho....

Why am I using a different UHF driver and horn? My UHF dispersion pattern is the same as the 2380A mids with that, and I'm good to 30 kHz. I'd use a smaller tweeter horn, if JBL made one. There are alternatives, tho....

[macaroonie]

Thanks Zilch
It looks as if you guys have done a lot of groundwork on the network and from what i can gather the 2405 is pretty much stand alone within its application. Why not 8.5kHz as in the original x/o although I realise you have structured the MF lo pass to the higher frequency. Lets face it the slot is only handling about 1 octave so I don't expect power handling to be an issue.
I had a look about to price 2450 drivers---- yikes. There is very little chance of them showing up at a sensible price over here and by the time they were shipped from the US our tax would throw them sky high.
I have seen some threads regarding 2235 in smaller enclosures. My units came from B380 subs ( the cabinets drowned ) and that enclosure is somewhat smaller than I am proposing. I assume that a correct if limited alignment can be achieved with my size as proposed (4.5 - 5 cu ft ).
I pushed the bass driver to the side because there is a spare 2.5 in. against the horn width thereby creating two nice pockets for the port (s) to live in, although they (it) could easily be put on the back. Also I have noticed some discussion about baffle placement diffraction effects etc.
What is the current thinking / experience re the positioning of the slot. is dead center the best plan or offset to some degree. I'm thinking of some of the older monitors where the slot is to the side of the lens, I know the factory provided for mirror imaging but ??????
These are just some early thoughts and other than the size almost anything is possible. J
Just as a matter of interest has anyone gone down the other path and run a similar system 100% active. There are plenty of 3 way electronic x/overs out there. What are the pros and cons of this approach and Q. should any zobels etc be left in place in this configuration.
Thanks Mac

[Zilch]

8.5 kHz 2405H adaption of "Keeper" crossover is now posted here:

http://audioheritage.org/vbulletin/s...246#post130246

[macaroonie]

Zilch I think you are in line for the Bottle of malt. You have done a fantastic amount of background work in this area. Send me a PM let me know where you are please. Mac