Sunflowers redux build

[naboo007]

My parts for the Sunflowers redux build have arrived ... very excited to get going. It will take me some time to complete this build, I think - due to various reasons (one of them being wanting to use wood that is still attached to a tree...but more about that later).

I'm struggling a bit with the volume of the woofer box. On the site it says that it must be approximately 42 litres. If I take the sizes given on the site, and I assume that 3/4 inch thick wood was used in the construction, then I keep getting to different sizes for the internal volume of the 3d trapezoid.

I'm weary of just using the exact dimensions, so I am going to adapt them but just make sure that I will have an internal volume of 42l - from the text on the site it seems like this is more important than the dimensions.

Please let me know if you know whether the overriding factor should be 42l or the given dimensions.

Thanks in advance,
Martin

[Chris Roemer]

I end up w/1.3cf (about 38L?) using Paul's dims.

Here's what I'd do. Shoot for 40L (1.4cf) w/a tune in the high 20s (27?).
You can get there by using a 2"id port that's 7" long, OR
a 3"id that's 17" long (elbows are allowed). (Actually, I LIKE to use 4" ports w/10" woofers - but that's me.)

Keep the same baffle dims (this will match the upper section, the dims of which are CRITICAL) and do what you will depth-wise. This will set your tweeters at the same level Paul designed them at. Also, I'd put the woofer on the same spot on the baffle (I'd put his port in the same position as well).

[rpb]

It's easy to reduce the effective volume after completion by adding filler material, so you could go a little larger if you want.

[djg]

I get 40.2 liters. I'd build it to the drawing, it seems accurate, a bit wonky with the depth measurements on the side view going to the back of the baffle which might trip you up. You only subtract 3/4" from the top and bottom measurements to get internal distance. 40.2/42 a typo? JMHO.

Edit: I looked at the color rendering by Paul C., below is a B&W line drawing by "Robert F." that is different in that it takes the measurements from the color rendering and makes them the total external measurements. Perhaps Paul C. can fix this, they can't both be right. In the meantime, I'd go with Paul C., he designed the things.

[naboo007]

I end up w/1.3cf (about 38L?) using Paul's dims.

Here's what I'd do. Shoot for 40L (1.4cf) w/a tune in the high 20s (27?).
You can get there by using a 2"id port that's 7" long, OR
a 3"id that's 17" long (elbows are allowed). (Actually, I LIKE to use 4" ports w/10" woofers - but that's me.)

Keep the same baffle dims (this will match the upper section, the dims of which are CRITICAL) and do what you will depth-wise. This will set your tweeters at the same level Paul designed them at. Also, I'd put the woofer on the same spot on the baffle (I'd put his port in the same position as well).

Thanks Chris. I still think it might be better to shoot for 42 l - but that's based purely on the fact that it is in BOLD on the website

I will make sure I keep the baffle dimension the same. Since this is critical, let me rather ask the question: So the front baffle is 11" wide, exactly. If I want to make a rounded edge with a router, should the width be adjusted at all, to compensate for it?

[Chris Roemer]

You'll be okay (I prob. didn't have to U.C. "critical").

[rvsixer]

...below is a B&W line drawing by "Robert F." that is different in that it takes the measurements from the color rendering and makes them the total external measurements.

Actually I sized the woofer box so it would be inline with tuning per Curt C ( http://speakerdesignworks.com/Sealed_v_Vented.html ) for added flexibility (see article conclusion), since I always seem to prefer sealed alignments with lowish Qtc.

I tried to like them ported, but after lots of experimenting and in-room measurements; I sealed them up and they have been crossed over to multisubs the last 9 years or so and love the setup .