Heather's new L200 JBL Dynamics Project

[Mr. Widget]

It is really hard to guess what the internal dimensions are because of the furniture nature of enclosure. My guess is that the internal volume is likely around 6 cu ft.
More than enough for a 2216ND.


Widget

[RMC]

Quickly.

Though the math is right for ext. box dimensions/volume, the assumption it might lead to a 4-5 cu ft internal volume sounds like "creative accounting" since it would represent approx a 50% box size reduction from the 9.32 cu ft. Overly optimistic in my view, likely more than 4-5 cu ft. internal. Sorry. Two options to make this more realistic.

1- Measure internal dimensions (if possible), then do the same calculations as before, after that subtract about one cu ft for volume displaced by woofer and bracing. This will give a closer actual Vb figure of the dedicated box.

2- In absence of internal dimensions and/or of an accurate panel(s) thickness number(s), assume 3/4" material and calculate/add the volume of each box panel to get a total number for these, this is to be subtracted from the 9.32 cu ft since it was an external box volume. Moreover subtract about one cu ft for volume displaced by woofer and bracing. This will also give a closer to real life cab volume figure.

Some panel overlaps may make the calculations a bit more tricky but these should be quite small numbers of low impact, so nothing to lose sleep about if they're not fully or correctly considered in the calculations.

[hjames]

Well, the fact is that I don't actually own the Valencia speaker cabinets yet so I can't measure the interior.
I DID have a pair of Heathkit Valencias I was modding for quite a while but sold them about a year ago.
I've been offered some empty Valencia cabinets and I'm trying to discern if they are a reasonable box
to use for the 2216ND speakers I do own before I go through whatever logistics are involved in obtaining them.
That said, it does sound as if they're of a volume that'd work for this project.

[rusty jefferson]

If I'm reading the dimensions on these drawings correctly the 846A is 5.7 cubic feet empty and the 4367 appears to be about 5.5 cubic feet.

https://www.google.com/url?sa=t&sour...53ywEy7QjYonWn

[RMC]

I get 6 cu ft internal for an empty 846A cab, pretty close to the other result. Not easy plans to deal with and figure out some things, clarity isn't its best asset, even with the large amount of details given.

As for 2216nd suitability in such box one should model it in speaker software using various tuning frequencies in order to decide about the best outcome (LF curve shape) vs expectations or user needs.

[Robh3606]

Hello Heather

I am using 4.7 cubic ft for my 2216's They are tuned to 25Hz and I use the same alignment as used in the B380/B460. I only use +3db instead of the +6 in the BX-63.

When I was setting things up I had a 32Hz option and can run them with no LF boost and on most music they sound fine.

A larger cabinet will be fine. I am on the "small" size by design to keep the whole system size in check and don't use the volume behind the waveguide.

Might want to think about a custom cabinet if only to get the woofer "off the floor".

Rob

[hjames]

Hello Heather
I am using 4.7 cubic ft for my 2216's They are tuned to 25Hz and I use the same alignment as used in the B380/B460. I only use +3db instead of the +6 in the BX-63.
When I was setting things up I had a 32Hz option and can run them with no LF boost and on most music they sound fine.
A larger cabinet will be fine. I am on the "small" size by design to keep the whole system size in check and don't use the volume behind the waveguide.
Might want to think about a custom cabinet if only to get the woofer "off the floor".
Rob

Thank you, Rob!

Couple ideas - I tend to add wheels to the bottom of the larger cabinets I have, makes it easier to move and to clean around it, as I did with the Heath/Valencias last year.

Like I say, I don't have them yet, just thinking through possibilities if I go that route.
I did some measurements with the Heathkit/Valencias I had last year, to get an idea of the general height.
I had furniture wheels screwed directly into the bottom of the cabinet just inside the factory plinth, which lifted it maybe 1.5 inches.
The 3-way crossovers I built fit just under the smith horns, so the dimensions are pretty close to the mockups.

[Robh3606]

Thank you, Rob!

Couple ideas - I tend to add wheels to the bottom of the larger cabinets I have, makes it easier to move and to clean around it, as I did with the Heath/Valencias last year,
so I'm thinking - if I made a Plinth/footer "skirt" to go around the factory base I could get wheels under it as well as lift the woofer higher off the floor.
What do you think - lift them 8-10 inches or so?

Like I say, I don't have them yet, just thinking through possibilities. I found this stock image online.

Hello Heather

I like to do that too! I did the same thing for my 4344 clones. They are on 12" stands more in line to get the 077 at seated ear height.

I think you have a good plan and you could experiment with the height so the HEIL doesn't get too high or low like the 077

Rob

[hjames]

I've been busy in retirement with other projects, yardwork, cleaning up after trees that blew down, and more recently cast iron drain pipe issues.
And downsizing - selling off old furniture from my folks and grandma and making room. But fortunately I've kept a decent system in place so I can unwind
with music when I get the chance.
And now, early November 2023, the Dynamics project made a step ahead.
I heard from Subwoof, who is also in the verge of retirement, and downsizing all of his spares and strays - and said he had a clean pair of L200 cabinets I might want!
Hey, I did an L200 project once before and liked the results!
So over the last week or so we got plans to meet up and get the cabinets.
Turned out it was the one weekend a year we go to my sister in law's place in Richmond and do the Highland Festival - bagpipes, drummer, beer, scotch tastings, and more.

Anyway, Mike and I met up saturday evening after the festival, exchanged greetings (its been a few years since last we met),
swapped the cabinets, and - darned if they didn't actually fit into my little Honda Fit for the ride back to Fairfax today!
It'll probably be a few weeks before I get the excess holes covered, get wheels underneath, and start assembling things -
but its a step in the right direction!

And - just to detail the electronics behind the current 2ch system:
I have a WiiM Pro as an audiostreamer (mostly tuned to Qobuz, but I can also feed from a large lossless digital music library on a macMiini in my office via Airtunes).
The streamer feeds a Topping E30 II DAC.
That feeds an Acurus RL11 preamp and an Acurus A200 power amp that replaced the Carver TFM-25 power amp I used most recently (both roughly 200w/ch).
I still have the Jolida Tube amp, tho its currently offline. I do have a Carver FM tuner I rarely use, and a Denon DF35 turntable that's rarely used.

But, the plain fact is - Emma and I are both amazed we got 2 JBL L200 cabinets in the back of the Honda Fit!
And got the lid closed for the 120 miles trip home!!
And, frankly, found room in our small house to get those things indoors!

[hjames]

Did my run to Home depot, got screws to mount the woofers, got wood to cover the excess holes I don't need, and silicone caulk to seal the wooden covers to the baffle board.
Tho I do have a few holes to fill with silicone (leaving just the single port remaining), and I will need to mount wheels underneath,
I have now basically completed installing the woofers into the 2 cabinets!
Phase 1 is DONE!

Need to find some room in the living room to set these up for testing, but I have do have one in place -
got the 18 x 18 granite tile topper in place, tho I need to play with the foam spacer to get the height right.
I've also got to dig out the Great Heils and make up some dual banana cables for the crossover outputs.

Probably got a couple days before I can actually run some music through them, but ... its so close!!!

[hjames]

DONE!! Initial assembly completed - music is playing!
But the heavy lifting is accomplished -
the darned Woodhorn/Midrange driver combo is 44lbs!
Time for breakfast and a celebratory Spaten Octoberfest!!
The fine tuning can happen as time allows!

[Robh3606]

Hello Heather

The Heil's look great perched up on the Smiths!!! 44lbs!!! What are you running alnico or ferrite??? One advantage of the neo's much lighter. Well one things for sure they aren't going anywhere!!

Rob

[hjames]

Doesn't sound right with the eBay sourced "Nelson pass style L300" crossovers. So I got the parts to build a pair of Giskard style 3133 Modified crossovers like I had for the last pair.
And bought a pair of 2405 slots from an ebay seller in Japan. They arrived today, and I went to Michael's hobbies to get a pair of small wooden boxes to mount the slots in.
Over the next few days I'll drill them with a hole saw, stain them to match the crossover boxes I built last year, and see how that works out,
but for now I put them in place for a brief test - yep, they got that sizzle!
Oh, I painted the foams black since I prefer that over their original dull brown.

[rusty jefferson]

....but for now I put them in place for a brief test - yep, they got that sizzle!...

So, you got the sizzle, but did you get the steak? :-)

I've never seen those tweeters turned that way......I assume they have wide horizontal dispersion and narrow vertical dispersion when mounted vertically? Is that a preferred position?

[RMC]

Actually JBL's Manual recommends that the slot be vertically aligned for best horizontal dispersion.

My understanding is that for a quick test to confirm working or not then orientation might be less important. However the user will not be in a position to fully appreciate the device's large horizontal dispersion during a test conducted the way shown.

And then there's the odd cases where users may actually prefer the "wrong way" to mitigate sound bouncing on side walls in a narrow room for example, or even another application which does require a wider vertical beam.

Richard