Sunflower center build begins - and some questions

[rvsixer]

Will keep you updated with my progress!

Please do! Though I love my Sunflower mains, they just take up too much room in my already small listening room, so have been thinking about building something smaller. I've always liked the Amiga's, it wasn't until your thread that I saw I already might have a good center match for them!

[Evan Steeves]

Hmmm I think there is a misunderstanding. The box needs to have a certain volume and a specific baffle height (both of our centers have the same baffle height). The box width and depth can change, as long as the target volume is met. I needed a shallower box, so the width increased.

All above not to be confused with driver spacing and diameters. I just found out why our layout looks different, is because it is different . Your tweeter CL to inside woofer CL is 3 1/2", and mine is 3 3/4" for whatever reason.

The theoretical ideal is to have all three front speakers equidistant to the listening position. In the real world, get it as close as you can to that and as practicality dictates, and use the AVR's speaker distance settings to compensate.

that makes sense, thanks for the explanation!

I am aware about the box volume size (I believe aforementioned rule of thumb is you can change the box design up to 10%, long as volume stays the same, in order to keep the response similar) vs the speaker distances. I just followed Paul C's diagram (which, as you mentioned, you didn't have), in hopes that I read and drew it properly off his diagram! Either way, just glad my circle cuts came out as good as they did. Great experience for my future builds and now I can get more complex/try new things on the next speaker

Will keep you updated with my progress!

[rvsixer]

AAh, perhaps therein lies the difference?... so I followed Paul C's posted box diameters. Now, am I able to place this speaker further back than the Amigas, since my TV is a bit behind the Amigas and the center channel looks better further back? Or is it more ideal to have center channel flush to tower speakers for wave diffusion/imaging?

Hmmm I think there is a misunderstanding. The box needs to have a certain volume and a specific baffle height (both of our centers have the same baffle height). The box width and depth can change, as long as the target volume is met. I needed a shallower box, so the width increased.

All above not to be confused with driver spacing and diameters. I just found out why our layout looks different, is because it is different . Your tweeter CL to inside woofer CL is 3 1/2", and mine is 3 3/4" for whatever reason.

The theoretical ideal is to have all three front speakers equidistant to the listening position. In the real world, get it as close as you can to that and as practicality dictates, and use the AVR's speaker distance settings to compensate.

[Evan Steeves]

IIRC there was no box design when I built mine. Paul gave me a target baffle height and volume, as long as those two parameters are met every other box dimension can be changed without affecting the sound. I sized mine to suit my TV/stand setup.

AAh, perhaps therein lies the difference? I have quite a bit of space to play with under my television, so I followed Paul C's posted box diameters. Now, am I able to place this speaker further back than the Amigas, since my TV is a bit behind the Amigas and the center channel looks better further back? Or is it more ideal to have center channel flush to tower speakers for wave diffusion/imaging?

[rvsixer]

However, if I recall, didn't you slightly modify the box parameters (31-inch long as opposed to 28-inch, and slightly less tall/deep)?

IIRC there was no box design when I built mine. Paul gave me a target baffle height and volume, as long as those two parameters are met every other box dimension can be changed without affecting the sound. I sized mine to suit my TV/stand setup.

[Evan Steeves]

It's a simple sealed box, where everything is accessible from the woofer holes, so IMHO no need to make the rear panel removable.

Suggest making the crossover in two pieces, get some practice cardboard to see exactly how big you can go and still fit through the woofer holes, cut two pieces of crossover board that size, and go for it. Pic of mine here:

http://techtalk.parts-express.com/filedata/fetch?id=1142976

I am still wondering why our tweeter spacing is so much different. Maybe I made the mistake laying mine out LOL .

hey, if anything, I would be the one with the mistake! Not sure why the spacing is different, doesn't look TOO critical, but hopefully it should not affect the sound much. I used measurements from the edge of my 28-inch panel, using my engineering drawing kit, following Paul C's diagram for spacing. However, if I recall, didn't you slightly modify the box parameters (31-inch long as opposed to 28-inch, and slightly less tall/deep)? Or was that another user?

Thanks for the words of wisdom, I DO like the idea of having crossover in 2 pieces although I already have it built in one long piece. You are right, with the size of these woofers, everything is accessible through the holes...hell I could even solder in a new component through the holes if need be :P

I actually still have to drill the holes for the speakers and tweeter tonight or tomorrow night, then glue the crossover in, test everything, then I will glue in the top and back and DONE! (for now, until Veneering time in the spring)

[rvsixer]

It's a simple sealed box, where everything is accessible from the woofer holes, so IMHO no need to make the rear panel removable.

Suggest making the crossover in two pieces, get some practice cardboard to see exactly how big you can go and still fit through the woofer holes, cut two pieces of crossover board that size, and go for it. Pic of mine here:

http://techtalk.parts-express.com/filedata/fetch?id=1142976

I am still wondering why our tweeter spacing is so much different. Maybe I made the mistake laying mine out LOL .

[Evan Steeves]

hmmm...struggling to decide wether to put extra time/work into making the rear panel removable or not. Last night, glued the front baffle and side walls onto the base, everything is nice and square...even more so than my Amigas were. Now, since I have only the top and rear left to glue, if I decide to make the removable, it will mean I have to wait a few weeks longer...I do not have access to saw here or the desire to use power tools inside my condo, I would have to wait to cut some thin wood pieces next time I visit my dad, so that I could glue them along the edges of the bottom/top/sides to screw the rear panel in.

My amiga rear panels are not removable...but I figure if ever there was a problem, I could router out the back panel and then replace it after changes were made to interior or any problems solved...not sure how many of you guys have ever had to access the insides via rear in order to fix things?

[Evan Steeves]

Before you glue/close it up, how's the breathing room for the backside of the woofers? If they need some, a chamfer or cove bit, maybe even a roundover bit removes the extra material nicely. I prefer the chamfer bit myself. They might not need it though with half inch stock. You could use poly fill pillow stuffing to dampen it if needed. Here's a pic of the chamfers I did on a project recently... Oh, and your box is looking good too.

Good tip! I actually thought about that, but since the baffle is half-inch stock, when I test fitted the speaker, they seem to have ample breathing room. I also donèt want to thin out the front baffle too much where I trimmed it for flush mounting of speakers.

thanks for the positive feedback :D At some point this spring when it gets warm I will need to take both my amigas as well as this center channel, remove speakers and get the veneer done

[Jeff F.]

Before you glue/close it up, how's the breathing room for the backside of the woofers? If they need some, a chamfer or cove bit, maybe even a roundover bit removes the extra material nicely. I prefer the chamfer bit myself. They might not need it though with half inch stock. You could use poly fill pillow stuffing to dampen it if needed. Here's a pic of the chamfers I did on a project recently... Oh, and your box is looking good too.

[Evan Steeves]

Up North here, us Canadians don't take a day off...rain, shine or below freezing weather with snow!

couple of pics of my snowy speaker box build! pretty happy with my first time using a router!



























still missing the back piece since I ran out of 28-inch stock. will go to Home Depot tomorrow on my way from my dad's and have them cut the final piece :D then I can glue and clamp this week! can't wait to hear the final result.


As this a sealed cabinet, does anyone have any input on interior treatment? I figure putting a thick bead of titebond around the edges after gluing up the cabinet should guarantee a good seal. As there is no port, I assume no need for PSA foam on walls.

[Evan Steeves]

I have that router, got it for the same reason. Mine was $89 when HD had it for $25 off during the 2015 Christmas season. It's a very nice tool and I didn't feel the need for the plunge base, just tilt it into the cut, works great.

As far as the speed control, for "thin" bits, high speed. Slower speed for larger bits like a 3/4" round over. If you think about it, the larger bits have a faster speed at the cutting edge because of their larger radius.

Perfect information, thank you for this! Since I am using 1/4'' diameter bit, I will go with a higher speed, maybe 5 out of 6 to start.

Things here in Canada generally cost more, we don't get those same awesome deals. Although, the plunge router base is really quite awesome, and I am quite glad I got the kit and not just the router. As you said, I could have twisted the adjustment ring to bring it down once it was set up and running, but I love the versatility of the plunge attachment and how I can easily set it up for the perfect depth without guessing. Also, I was not really sure that the Jasper 400 would have fit on the smaller router base, but fits perfect on the plunge router base. Hoping that my friend has some free time one night this week (but mostly that he is WILLING) to go back to his shop and get to work on this baffle. He was feeling lazy all weekend and so we didn't get to go.

[Evan Steeves]

Did you double check the driver spacing layout, and driver recess diameters? I looked at my Sunflower CC this morning, and have about 3/16" between the XT and RS125 cutouts.

3/16'' makes sense actually, so I should be good! Yes I double checked with Paul's 3D diagram after drawing all circle cutout lines.

[Millstonemike]

Have barely worked with router so far. The router I got has variable speed - should I be setting it faster or slower for clean finishing on MDF?

I have that router, got it for the same reason. Mine was $89 when HD had it for $25 off during the 2015 Christmas season. It's a very nice tool and I didn't feel the need for the plunge base, just tilt it into the cut, works great.

As far as the speed control, for "thin" bits, high speed. Slower speed for larger bits like a 3/4" round over. If you think about it, the larger bits have a faster speed at the cutting edge because of their larger radius.

[rvsixer]

Dayton drivers and the tweeter are a little tight, no? I get that you want to be as close as possible, just hope the flush mount cut-out portion will cut well

Did you double check the driver spacing layout, and driver recess diameters? I looked at my Sunflower CC this morning, and have about 3/16" between the XT and RS125 cutouts.