DIY-project: JBL Kebnekaise S4365

[bubbleboy76]

Those look great and well integrated!
I bet you already started listening without horns

Is that mattress foam you are using of open-cell type ?

No listening yet. Will do the speakon speaker-cables today (using Canare 4S11-cable).

I will use the LSR305:s as tops, until I get the horns (just some temporary textbook electrical LR24 crossover at 80Hz is my plan).

Don't know about the foam. I was recommended this mattress by speaker-people in Sweden that has measured it in closed boxes, and compared it to other damping materials.
It is this one:
https://jysk.se/sovrum/madrasser/sku...10#store_stock

It comes compressed, and kind of expands over the course of 2 days. So it sets itself a little bit tighter inside the box, I think.

[ivica]

...
Don't know about the foam. I was recommended this mattress by speaker-people in Sweden that has measured it in closed boxes, and compared it to other damping materials.
It is this one:
https://jysk.se/sovrum/madrasser/sku...10#store_stock

It comes compressed, and kind of expands over the course of 2 days. So it sets itself a little bit tighter inside the box, I think.

Hi
Comparison between the diffuse field sound absorption coefficients of:
sheep wool sample S4,
mineral wool,
recycled polyurethane foam and
polyester fibers (PET).



https://www.ncbi.nlm.nih.gov/pmc/art...10-01277-f007/

regards

ivica

[bubbleboy76]

Hi
Comparison between the diffuse field sound absorption coefficients of:
sheep wool sample S4,
mineral wool,
recycled polyurethane foam and
polyester fibers (PET).



https://www.ncbi.nlm.nih.gov/pmc/art...10-01277-f007/

regards

ivica

I have seen something like this before, a combination of sheep wool and foam seems to be good for
my box inteded range (20-650Hz).
someone told me that it is best to have sheep wool closest to the element.

[bubbleboy76]

Horn box design.

The bottom will be openable with a lid.

I have left the idea of enabling a vertical horn position. But, the box will be able to be put in the middle between the LF-boxes, if I would want an MTM-topology later in life.

[bubbleboy76]

Work in progress.

[pos]

The black and white contrast will certainly look nice on that one!

[bubbleboy76]

The plan was to paint it all white.
But now you make me hesitate.

[1audiohack]

That is stellar work! Very nice.

Barry.

[bubbleboy76]

Adding bat-slayers to the mix.
Bought a pair of 045be from ebay. Thanks Johanwholst for the tip!
I hope they work....

From this graph it seem they will not need much dsp when used 10-20KHz.

There will be comb-filtering with the crossover to HF horn with 476mg. Maybe very steep slope would be applicable here? I have FIR-capability, so I can do very steep, if I want.

My HF horn/driver beaming starts at 8KHz. So the plan is to crossover at 8-10Khz somewhere.

[johanwholst]

Testing mine at down to 10k as we speak. They do a fine job down there with a steep crossover

Hope they arrive in good shape. Im sure you will like them

[bubbleboy76]

What is the lowest frequency a JBL 476mg compression-driver can play safely, without risk of damaging it long-term? Let's assume a 48dB/oct high-pass filter, and "normal" home-listening levels. And H4365 horn-loading.
Anyone?

[bubbleboy76]

Testing mine at down to 10k as we speak. They do a fine job down there with a steep crossover

Hope they arrive in good shape. Im sure you will like them

Have you tried even lower crossover with your 045be-1? I am thinking about 8K crossover, because it is there the beaming starts on my LF-horn. And the distortion is lower in that area for 045be than 476mg, according to the specs.

[bubbleboy76]

It went white. Like the top of mountain Kebnekaise.

[johanwholst]

Have you tried even lower crossover with your 045be-1? I am thinking about 8K crossover, because it is there the beaming starts on my LF-horn. And the distortion is lower in that area for 045be than 476mg, according to the specs.

I have been testing out different xo lately and use it from 10k now. This is the lowest i tried them. No reason to go lower with 2384 but you must use your ears to judge with your midhorn.
I Like your paintjob!

[johanwholst]

Btw did your 045be arrive safely?