CR Treatment and Tuning---The home stretch!!

[Stadank0]

Har har....

It does kinda look like a plane fuselage..huh

[Stadank0]

Not too exciting, but though I'd better post something before the thread goes stale!

gonna do a 3 tone scheme with the boards. They will have a dark cappuccino stained accent 5" down with a light chocolate color flat paint, then a black 4" satin paint at the bottom...Think it will look cooler then a boring solid color...

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[Stadank0]

The finished boards....Weather got me again. Still need to do some more sanding on some of the ribs. Install will only take about 2 days after that.

Stuart, I picked a used BSS (Soundweb London) blu-102 cheap for digital tuning later. The Blu series was recommended to me....any experience with the product line?

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[Soundman2020]

Slats are looking good!

I picked a used BSS (Soundweb London) blu-102 cheap for digital tuning later.

Ummm... are you SURE you got the right thing? This one? https://bssaudio.com/en/products/blu-102 That's the only "Soundweb BSS Blu-102" that I could find... But I don't see what application it would have in a studio! And the specs don't mention anything at all about tunable high precision digital filtering... It is listed as a "Conferencing Processor with AEC and Telephone Hybrid"! Color me confused... Or maybe there's another "Soundweb BSS Blu-102" out there, that I didn't find?

Anyway, I'll PM you later with my recommendation for the digital tuning box.

- Stuart -

[Stadank0]

Actually the Blu-50 was the recommended unit. I bought the 102 after using a comparison chart. I sent you a PM to go into more detail...


The 102 has all of the audio signal processing capabilities that the Blu-50 has with all of the added junk that we don't need. I got this used for a fraction of the cost of the blu-50, so I bought it...It has signal processing tools for days along with phantom power and 48db of gain on every input. All done with an object oriented software UI. Its way overkill, but usable.


PS: I think I can even handle the programming side of it if you don't want to deal with the UI. I'm picking it up pretty fast.

[Stadank0]

Rain, rain and more rain....should have some more pics up by Saturday evening...

[Stadank0]

Back to work but nothing to show off today...In the meantime, here's a kitty who knows how to put a fine monitor to good use!!

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[Stadank0]

Hi Stuart,

I have an issue with the upper row space on the left side. Looks like a combination of issues with the soffit box are causing the gap to dip to 13.50". Its out of parallel and I didn't catch it until I put in the rib below for test fit. The other ribs are spaced properly to each other and the right side is fine. Hoping that since its up towards the ceiling that it won't matter much.

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Also, just off the floor the rib is hitting the electrical coming through the wall. I moved it down .75". I know this will change the tuning , so I wanted to run it by you to see how bad that would be.

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Fun times!!

[Soundman2020]

Good to see the progress, Frank! Glad the weather (and the cat!) is finally cooperating.

I'm not sure if I understood the first part of your dilemma correctly; Is the issue just that the two ribs are not parallel? In other words, the cavity won't be rectangular, but slightly trapezoidal? Not a problem. The slats run vertically here, so having the ribs the same distance apart is not a problem. Don't sweat it. It won't change the tuning.

For the second part of your dilemma, that's also not a problem. Moving the entire rib up or down a bit is OK, as it does not change the tuning in this case, once again because the slats run vertically. It would only be a problem in a "traditional" slot wall, where the slats run horizontally.

Yes, in both cases the volume of the cavity does change, but in both cases it is not an issue as it does not change the tuning: for a slot wall, the total volume of the cavity is actually not relevant: it's the depth behind each slat that counts for the tuning. Non-intuitive, I know, but correct. It's due to the way the math works out for slat resonators: you end up dividing the height by itself, so the answer to that part is always "1". In other words, in the equation there is a division taking place, and you have "H" above the line along with "H" below the line, so they cancel each other out. Thus, "Height" of the cavity does not matter for tuning. It only matters for total effectiveness, and there's still plenty of "H" left for that, so it's not an issue.

Once again, it's not an issue in YOUR case, since these slats run vertically. It WOULD be an issue for someone else's case if his slats run horizontally.... and in that case the LENGTH of the cavity would not matter, while in your case the length of the cavity IS important. It's a matter of perspective.


- Stuart -

[Stadank0]

Well,

Now I did it!..I went and installed all of the deep vertical dividers at 17" from the end instead of 16". I decided to make the ribs an inch shorter to get rid of the notch and just slap a 2x4 up against the ends since the framing didn't match anyway. What I didn't remember to do was set them at 15" to compensate.....So effectively they are an 1" off of where they should be..

The line in the screenshot shows how I made the ribs an 1" shorter. How bad is it? hate to bust out and reset the vertical dividers if I can help it. I was starting to put in the shorter ones when I noticed my mistake.I'll wait until I hear back....

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[Soundman2020]

Now I did it!..I went and installed all of the deep vertical dividers at 17" from the end instead of 16".

Ooops! Not so good... Let me think about that a bit, and re-do some of the calculations.

The main issue here is that the vertical dividers will no longer fall in the center of the slats, as they are supposed to, which de-tunes those slats from where I wanted them to be. The dividers are supposed to line up on the center-line of those slats, but now they'll be offset by an inch, which is a large change. I'll have to run the numbers to see how much the frequencies will be shifted, and if they will still be within the range that I had originally planned. There's a little wiggle room here for slight imperfections, but not much, so let me work through it a bit...

However, I won't be able to do that tonight or tomorrow (it's the weekend!), so it will have to be Monday morning before I can get to it. As soon as I can, I'll take a look and let you know if it is still OK or not.


- Stuart -

[Stadank0]

Cool thanks,

Worst case I can bust em out and reset them. Keep in mind that I only set the deep ones. Also you may want to look at the model because the dividers in question are on the edge of the slat and the shallow ones are definitely a bit off center.

Overall a fix won't be that bad.

[Stadank0]

Have you seen what I'm talking about in the model? Stuck until we sort that out. I think the divider locations are going to have to be moved if they need to be center line of the slats.

[Soundman2020]

I think the divider locations are going to have to be moved if they need to be center line of the slats.

OK, I did some calculations and checking, and as long as the dividers are not closer than about 4mm to the gap, then we are OK. In other words, there must be at least 4mm between the edge of the slat and the start of the divider.

This does re-tune those slats, yes, but the overall change isn't too bad. The tuning is still within the range I am shooting for.

- Stuart -

[Stadank0]

Cool thanks...