10F/8424 & RS225-8 FAST / WAW Ref Monitor

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I am working on a Flatpack for TL GB. The baffle design will have an enlarged top baffle plate to allow the driver rebates to be cut prior to assembly. Here is the basic plan before the cut sheet is made for individual boards:
1710101711627.png


Here are the side panels (2):
1710101868660.png

1710101895887.png


MDF or birch faced poplar plywood (all 3/4in)?
 
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XRK, this is awesome. I have actually be considering doing exactly the same to get a set cnc cut, starting from Jofland's stl.
I was considering whether to create channels or tongue and grooves/dovetails to make assembly easier as well. Might be an idea?

Is 3/4" = 18mm or is it 19mm?
Most non-imperial supply is 18mm plywood I believe.

I've actually been considering whether I could make an inset FR "baffle" that can be swapped in and out to try different FR drivers in the 10f location.
 
XRK, this is awesome. I have actually be considering doing exactly the same to get a set cnc cut, starting from Jofland's stl.
I was considering whether to create channels or tongue and grooves/dovetails to make assembly easier as well. Might be an idea?

Is 3/4" = 18mm or is it 19mm?
Most non-imperial supply is 18mm plywood I believe.

I've actually been considering whether I could make an inset FR "baffle" that can be swapped in and out to try different FR drivers in the 10f location.

Mitch311,

I have come across 3/4" plywood that has varied in thickness between 17.5-19mm; I have also found that the ply can expand slightly due to temperature and humidity, and depending on how it has been stored.

You can get a sample piece of what ply you are planning to get, and maybe have 0.5 1.0 mm extra in the "groove" - as there will be wood glue also.

Regarding removable panel for the FR part, it's an idea worth considering - I did my build with the entire top part of the baffle as a removable piece.
 
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Iā€™ll be adding 6mm diameter wooden dowel alignment holes to help ensure a speedy and accurate assembly with basic clamps.
FAST-TL-Flatpack-Dowel-Pins-Plan.png


Let me check on the exact width of the wood we will be using. I think MDF is exactly 0.75in thick bit plywood might be a little different depending on the brand.

Purebond brand ā€œ3/4ā€ inch plywood is 0.703in thick.
 
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I'm testing an experimental low-distortion microphone I designed. Is this consistent with other measurements of this speaker?

View attachment 1284657

View attachment 1284660
That does look like the measurements of the sealed cabinet. As I recall it starts rising below 200Hz or so when I applied Linkwitz transform, but flat even in the bass region which was one reason the woofer works so well. But this is all dependent on how hard you drive it. What were your drive levels in Vrms?

Old measurement with active crossover but no LT applied:

1710163130140.png


With passive XO and XPS foam sealed cabinet, here is what I got for 2.0Vrms and mic at 0.5m:

XPS-Cabinet-2.83vrms-0.5m-Distortion-Graph.jpeg


Here is BB ply cabinet with passive XO:

BB-Cabinet-2.83vrms-0.5m-Distortion-Graph.jpeg


Measures to reduce panel vibrations using Noico and internal eggcrate foam were used:

10F-RS225-FAST-Cabinet-Noico-Liner.jpeg


10F-RS225-FAST-Cabinet-interior.jpeg


10F-RS225-FAST-Cabinet-overall.jpeg

10F-RS225-FAST-Cabinet-back.jpeg

Itā€™s not a bad looking speaker!
10F-RS225-FAST-Cabinet-baffle-detail.jpeg
 
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I used a SPL-8810 SPL meter to set them at 87db and 96db at 1KHz. Drive level is 3.024Vrms and 8.52Vrms. there may be some error since I was just holding the SPL meter by the mic.

It is a Primo EM200 with a 1-transistor circuit that lets me use it with a standard pink mic jack. That is ~800uA and an input impedance of 1.5-2.7k. It's not meant to be the end-all of microphones, just something I can plug into almost anything. The limitations of this approach are obvious and the noise is significant, but I wanted to see what was the best I could do with the most common interface and no battery.
 
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Hi X,
Using the old cut plans, I cut my side panels to 40" x 16". I was planning to trim to 40" x 15.75" and I was going to sandwich the baffles between the side panels. I would prefer a clean look on the upper baffle and would like to ask if I can build the enclosure with the side panel dimensions of 40 x 15.25" x 22.50" for the top section and 40.00" x 16.00" x 17.50" for the bottom section. This is basically reducing the depth of the enclosure by 0.50" and a reduction in volume of approx. 163 cubic inches.

If not, I will propose other options.

Thanks for the help
MM
 
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The dowels are meant to serve as alignment guides, not to provide mechanical binding force like a screw. This reminds me of IKEA furniture screws.

The FAST TL flatpack uses 50 alignment dowels. They will greatly make assembly easier and the boards wonā€™t ā€œsquirmā€ out of alignment under clamp pressure.
Here is one panel, the other one is mirrored. There are 4 more dowels on the front baffle where the speaker cutouts are.
1710536320691.jpeg

IMG_1794.jpeg
 
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Yes, but not easily. Itā€™s not a matter of changing the exit to a round hole of the same area. The internal TL inside needs to transition from a rectangle to a round. Otherwise it presents a sudden change in cross sectional area. Then it becomes what is called a ā€œmass loaded TLā€. This type of TL has a different dynamic than a tapered TL. It would be a new design with probably fewer folds. You can do it with a technique called the ā€œaccidental mass loaded TLā€ or AMTL if you do not have the means to simulate one from scratch.
 
Has anyone ever made a wooden version of the dagger?

Iā€™ve been thinking about the math of that, as Iā€™ve been considering how a dagger sat on top of the TL would work.

I believe XRK has mentioned previously that if the full ranger was separately boxed on top it would have to be moved backwards 3ā€. This is for time alignment I believe?

Are there any other considerations? Keeping it within 7.5ā€ ctc spacing would also be a little difficult. The distance would likely be closer to 8.5ā€.

Would a free air wooden dagger TL with a rounded over end cap, set with the driver create a good diffraction enclosure?

Iā€™m considering this as Iā€™d like to be able to easily audition a number of different 2.5ā€ - 4ā€ on top of the Rs225 TL using active crossovers.