[dkordonowy]

Hi all.  I've read some of the discussion regarding speaker enclosures as I'm getting ready to build a kit for the kitchen, but still have some questions that hopefully are easy to answer.  I would like to make a small 2-way enclosure with either the AV-1 or M130X/NEO3PDR drivers.  The SAF would be significantly raised if I could make a shallower speaker.  I modeled something up that keeps the same enclosure volume as the AV-1 kit and the same front and rear baffle.  Instead of the (relatively) deep sides though, I changed it to an octagon shape (at 45 degree angles).

Will this work?

If so, are driver/crossover kits for the M130X/NEO3PDR available to purchase?

Thanks!

[Danny Richie]

Will this work?

It will "work" but isn't going to be optimal. However, you have to pick the compromises that best suit you.

for best sound quality its good to have depth behind the woofer. I'd say that the width needs to be no more than 1/2 to 2/3 of the depth. This keeps it within the "golden ratio".

If so, are driver/crossover kits for the M130X/NEO3PDR available to purchase?

I have been working on those today.

I completed a network yesterday for the M-165X and the Neo3pdr with deep back cup. It turned out really good.

Next is the M-130X and M-130 with the same tweeter.

[dkordonowy]

Thank you sir!  I will try and find a way to keep the rear wall as far back as possible.

If it's possible, I'll call Monday to preorder the kit.

It will "work" but isn't going to be optimal. However, you have to pick the compromises that best suit you.

for best sound quality its good to have depth behind the woofer. I'd say that the width needs to be no more than 1/2 to 2/3 of the depth. This keeps it within the "golden ratio".

I have been working on those today.

I completed a network yesterday for the M-165X and the Neo3pdr with deep back cup. It turned out really good.

Next is the M-130X and M-130 with the same tweeter.

[JLM]

Ideally a sealed/ported cabinet would be in the internal ratio of 8:13:21 with none of the opposite sides parallel to the other to minimize standing waves.  At a minimum the front and back panels should be skewed so that first reflections of the backwave don't come directly back to the cone where they smear the cone action (or come through it as cone materials aren't totally acoustical opaque).

Secondly make sure the cabinet is very inert/rigid.  This is easier to do (and therefore less of an issue) in smaller cabinets (that produce far less energy intensive deep bass).  OTOH some cabinets have been measured to produce more external sound energy than the drivers, and all that wasted energy makes the speaker sound like the same untuned wooden box.

[dkordonowy]

Ideally a sealed/ported cabinet would be in the internal ratio of 8:13:21 with none of the opposite sides parallel to the other to minimize standing waves.  At a minimum the front and back panels should be skewed so that first reflections of the backwave don't come directly back to the cone where they smear the cone action (or come through it as cone materials aren't totally acoustical opaque).

Secondly make sure the cabinet is very inert/rigid.  This is easier to do (and therefore less of an issue) in smaller cabinets (that produce far less energy intensive deep bass).  OTOH some cabinets have been measured to produce more external sound energy than the drivers, and all that wasted energy makes the speaker sound like the same untuned wooden box.

Thanks for the info.  What about this design here below?  It attempts to leave as much room behind the speaker as before, with a trapezoidal shape (my wife likes the shape better than a regular cube).  The interior volume is the same.  The sides are canted at 5 degrees, while the rear has been shifted 15 degrees about the center (and also moved in 1").  This creates a coincident angle from the woofer that does not impinge back on the driver.

With regard to the inertness, I plan on making the front baffle a sandwich panel using kevlar weave skins sandwiching the MDF.  This should increase the stiffness of at least the front baffle...

[Danny Richie]

I think something like that would work out okay for you.

[dkordonowy]

Here is the latest iteration that I have designed:


The port has been moved to the front using a rectangular 6.5"x7/16"x9" port that is canted 30 degrees and slots below the woofer driver.  Thank you Danny for providing me the proper dimensions for the port (I think I copied them correctly, I was on the subway when I wrote them down).

There is now space underneath the speaker enclosure (behind where the port comes in) where I can potentially add an amplifier to power them.  I'm still working that part of the design.

Anyone see any immediate problems with this design?

[Danny Richie]

That looks pretty cool, but I am scratching my head a little looking at the port.

Am I just seeing one side of the port or something?

It looks like you have a diagonal piece of wood angled where the port would be if it were there or something. Then what is the other diagonal piece under the port that is at a different angle.

[dkordonowy]

That looks pretty cool, but I am scratching my head a little looking at the port.

Am I just seeing one side of the port or something?

It looks like you have a diagonal piece of wood angled where the port would be if it were there or something. Then what is the other diagonal piece under the port that is at a different angle.

Sorry, I didn't do a good job of explaining my thoughts, and this is my first build so I'm still learning.

The thin long piece at 30 degrees is the port.  The thicker piece underneath at 45 degrees is a brace for the bottom shelf, and is also there to attach the removable amp base.  I'm planning on sealing the holes in the base and front around the port so that air can only pass through the port.

It's a weird way to place the port I think, but maybe it will work...