Sunflower HT/Music LCR Build

[rvsixer]

Re: Sunflower HT/Music LCR Build

Ahh okay. It just is a little hard for me to follow the way it is laid out..

No worries, my fault I should have been more clear in my initial crossover post (that all parts are stock, no leads connected or trimmed or routed yet etc) :o . I am going to add my schematic interpretation to the post, hopefully that will clear up how it will be wired, and why the components are placed the way they are.

Your crossover location idea, and wrapping the top baffle with grill cloth is very interesting! Cool idea. I'd research if the double grill cloth would affect the dipole goodness of this design (since you would be altering not only the front but also the rear radiation pattern, and possibly how they are supposed to interact with one another).

[WernerM]

Re: Sunflower HT/Music LCR Build

The components leads will be trimmed and wired up per the schematic (i.e. R1 in series with C1, etc). Just looking to see if the inductor placement looks right (no crossing flux axes, minimal induction effects for other components, etc). My preference is one big board - it's a lot easier to get inside the bass bin from the woofer hole than three smaller ones, and less electrical connections/failure points to deal with.

Ahh okay. It just is a little hard for me to follow the way it is laid out, and as far as the inductor layout for those different effects, I am in the dark. I am planing to build this same design one day, and I was just going to put the crossover on the back of the front baffle, and cover the back with grill cloth as well as the front.

[WernerM]

Re: Sunflower HT/Music LCR Build

okay... If you have one lead of R1 coming off positive and other going to C1, that part is correct. I may be misinterpreting your layout. If you have the other lead of C1 going to one lead of L1 and one lead of C2, that is good, if the other lead of of L1 goes to negative from there, it really gets hard for me to follow your layout. Make sure that if you are putting all of these circuits on one board, you mark the tweeter + out, mid + out, and woofer + out. Negatives should be in the middle and all three drivers can connect from same negative point.

[rvsixer]

Re: Sunflower HT/Music LCR Build

I don't believe that is correct. It looks like you have R1 in parallel with C1 which creates and RC contour filter. Here is what I would and am going to do once I get my crossover components. Lay out all the the parts for each specific section, (tweeter, mid, woofer) on three seperate panels, and lay them out just as they are shown on the schematic

The components leads will be trimmed and wired up per the schematic (i.e. R1 in series with C1, etc). Just looking to see if the inductor placement looks right (no crossing flux axes, minimal induction effects for other components, etc). My preference is one big board - it's a lot easier to get inside the bass bin from the woofer hole than three smaller ones, and less electrical connections/failure points to deal with.

[WernerM]

Re: Sunflower HT/Music LCR Build

CROSSOVER LAYOUT:

I've laid out the crossover, using information from PE showcase ( http://www.parts-express.com/project...ver/xover.html ) and Curt C's article ( http://speakerdesignworks.com/nodal_analysis.html ). Let me know if you see any glaring errors, i.e. inductor layout etc.

I don't believe that is correct. It looks like you have R1 in parallel with C1 which creates and RC contour filter. Here is what I would and am going to do once I get my crossover components. Lay out all the the parts for each specific section, (tweeter, mid, woofer) on three seperate panels, and lay them out just as they are shown on the schematic

[rvsixer]

Re: Sunflower HT/Music LCR Build

It is hard for me to say since I don't know what the crossover schematic looks like...

Linky in first post...

[WernerM]

Re: Sunflower HT/Music LCR Build

okay, here is the schematic...

[WernerM]

Re: Sunflower HT/Music LCR Build

It is hard for me to say since I don't know what the crossover schematic looks like...

[rvsixer]

Re: Sunflower HT/Music LCR Build

CROSSOVER LAYOUT:

I've laid out the crossover, using information from PE showcase ( http://www.parts-express.com/project...ver/xover.html ) and Curt C's article ( http://speakerdesignworks.com/nodal_analysis.html ). Let me know if you see any glaring physical layout errors, i.e. inductor placement, etc.

[rvsixer]

Re: Sunflower HT/Music LCR Build

I see where you're coming from, but I would contact Paul C about that. I'd be willing to bet there is a method to his madness there. He's always willing to help out if you have any questions about his designs.

Probably a good idea, i just hate to bug him with more tech support questions ;).

[DIYNut42]

Re: Sunflower HT/Music LCR Build

PORT LENGTH?

Need some help with port length for the main woofer box. Paul C has one of the tunings at 23Hz with an 8" port length. However, when I run the numbers, I come up with 10.4" (using Paul's measured RS225-8 parameters) .

Physical box volume: 41.2L
Driver/Vent volume: ~3L
Calculation box volume: 38.2L
Port: Precision Port 2" (adjustable from 4"-11")

I get 23Hz tuning at 10.4" port length. This differs quite a bit from 8", but 10.4" is close to the alignment in Curt C's article on small vented box alignments ( http://speakerdesignworks.com/Sealed_v_Vented.html ).

I see where you're coming from, but I would contact Paul C about that. I'd be willing to bet there is a method to his madness there. He's always willing to help out if you have any questions about his designs.

[fastbike1]

Re: Sunflower HT/Music LCR Build

Good advice, but he's already talked about using pre-stain conditioner.

You should do a test on a scrap piece of the birch ply. Birch does not take stain evenly. I've heard you can use a solution of dewaxed shellac and isopropal alcohol to make it take stain evenly. Make sure to sand the machining ripples out first. Nice looking project! Keep us posted.

[Cosmic Charlie]

Re: Sunflower HT/Music LCR Build

You should do a test on a scrap piece of the birch ply. Birch does not take stain evenly. I've heard you can use a solution of dewaxed shellac and isopropal alcohol to make it take stain evenly. Make sure to sand the machining ripples out first. Nice looking project! Keep us posted.

[rvsixer]

Re: Sunflower HT/Music LCR Build

PORT LENGTH?

Need some help with port length for the main woofer box. Paul C has one of the tunings at 23Hz with an 8" port length. However, when I run the numbers, I come up with 10.4" (using Paul's measured RS225-8 parameters) .

Physical box volume: 41.2L
Driver/Vent volume: ~3L
Calculation box volume: 38.2L
Port: Precision Port 2" (adjustable from 4"-11")

I get 23Hz tuning at 10.4" port length. This differs quite a bit from 8", but 10.4" is close to the alignment in Curt C's article on small vented box alignments ( http://speakerdesignworks.com/Sealed_v_Vented.html ).

[rvsixer]

Re: Sunflower HT/Music LCR Build

I might have missed it if you mentioned it, but are you going to line the inside of the woofer enclosure or the open back mid area with any dampening materials? I think Paul mentioned in his write up that some simple egg crate foam inside the woofer cab would do some good.

I am enjoying Java right now (what happened to all the cool coffee drinking emoticons anyway...?).

No damping on the mids, I am fairly certain you want them as open as possible. I am going to try Walmart memory foam bed topper for the woofer box.