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I hate to bring this up at this late date, BUT . . . by my rather quick calculations, I think that this box is too small (maybe due to the slot vent?). I come up with about 0.4 cf, while the W14 SEEMS like it would be happier in more like 0.6 to 0.7 cf. ALSO, a 0.39 cf box with a 1"x 6.5" slot, that's less than 4" long will have a VERY HIGH tuning (which I believe has been questioned somewhere in this thread already)?
OK, so after looking up Paul's O.E. build, this box SHOULD be about 0.4 cf (so the box volume is OK), and the OP is using Paul's ACTUAL build for the slot vent, which SHOULD be ok. Odd thing is that Paul says it's tuned to the mid 40s, whereas I get something more like mid 80s, which MIGHT not be very good (WinISD models it as +7dB at 100Hz), BUT . . . if Paul designed it (and MAYBE he actually measured his own woofers - and probably did), so this box SHOULD be OK.
I'm just rambling here.
The high pass filter SEEMS like the cap/coil/cap "T" is OK, but the LCR looks like it would drop the Silky way down on the top end, to the tune of -3dB @ 11kHz, -6 @ 14k, and -8dB by 20kHz. I'd skip it (OR, build it in there with a jumper across it, so it can easily be defeated if need be). Has this filter ever been used before? Anyone else want to try modeling it? Am I doing something wrong here?
I GUESS peepaj did in-box measurements. Can this be correct?
Just trying to give the OP a good experience here. Maybe I should just go. Nevermind?
Chris
Last edited by Chris Roemer; 06-06-2013, 09:07 PM.
I hate to bring this up at this late date, BUT . . . by my rather quick calculations, I think that this box is too small (maybe due to the slot vent?). I come up with about 0.4 cf, while the W14 SEEMS like it would be happier in more like 0.6 to 0.7 cf. ALSO, a 0.39 cf box with a 1"x 6.5" slot, that's less than 4" long will have a VERY HIGH tuning (which I believe has been questioned somewhere in this thread already)?
OK, so after looking up Paul's O.E. build, this box SHOULD be about 0.4 cf (so the box volume is OK), and the OP is using Paul's ACTUAL build for the slot vent, which SHOULD be ok. Odd thing is that Paul says it's tuned to the mid 40s, whereas I get something more like mid 80s, which MIGHT not be very good (WinISD models it as +7dB at 100Hz), BUT . . . if Paul designed it (and MAYBE he actually measured his own woofers - and probably did), so this box SHOULD be OK.
I'm just rambling here.
The high pass filter SEEMS like the cap/coil/cap "T" is OK, but the LCR looks like it would drop the Silky way down on the top end, to the tune of -3dB @ 11kHz, -6 @ 14k, and -8dB by 20kHz. I'd skip it (OR, build it in there with a jumper across it, so it can easily be defeated if need be). Has this filter ever been used before? Anyone else want to try modeling it? Am I doing something wrong here?
I GUESS peepaj did in-box measurements. Can this be correct?
Just trying to give the OP a good experience here. Maybe I should just go. Nevermind?
Chris
This is my first speaker build. I'm currently using Dayton Audio satellites and I'm just trying to build something that's better for my mains. I'm sure this will be better. I have a subwoofer, my pioneer AVR only goes down to 50hz on xover. I like my speakers playing at 80hz anyways, at least for car audio. This should be fine for me I think.
Re: Please STOP. Asking for help (esp. peepaj) ? ? ? ? ? ?
I was wondering about the tweeter XO topology myself but heck, I'm not the designer, so who am I to question? As long as the final crossover is accessible after the build is complete, it would be pretty easy to bypass the LCR if the speaker sounds a bit dark.
Well that was easier then expected. Not sure if you're messing with me though as it cannot be that easy. :o
Not messing with you. It's correct. You can reposition some of the components to make that board more compact now. Also, it's OK to do two sep boards -- one for the woofer and one for the tweeter. A lot of people do that all the time.
Not messing with you. It's correct. You can reposition some of the components to make that board more compact now. Also, it's OK to do two sep boards -- one for the woofer and one for the tweeter. A lot of people do that all the time.
Thank you very much kind sir. I'm definitely going to do a separate board first. If I can move things around then that's wonderful. I thought it had to be like this lol. That tweeter schematic scares the living daylight out of me. I'll give it a go later tonight.
It looks like you have a great thing going on there. I put all my crossover components out on a piece of cardboard with the diagram drawn on it then I used 1/4 luan plywood and start drilling the holes, transfering and soldering the components. That's my method.
It looks like you have a great thing going on there. I put all my crossover components out on a piece of cardboard with the diagram drawn on it then I used 1/4 luan plywood and start drilling the holes, transfering and soldering the components. That's my method.
Oh yeah, I have some flooring I'll use. Just using cardboard as my cabinet template with the top measurement.
That is a lot of parts! The good news is, if you stick with it you can do it. I'm sure your next build will be much easier having tackled this one. It really is just a puzzle, like all puzzles it takes practice. Here's a few crossovers I've built, ranging from neat freak to compact, and a layout for one I did using two boards. Not trying to make your head spin, just giving you some ideas. The ground point seems to be something that first timers get confused about a lot, it is just a common connection between components. It can be one spot, or several places connected by speaker wire depending on the layout. Once you can wrap your head around how that works, the rest is just connect the dots. Then if you want it to look neat and tidy, fold it up and make it compact. I usually start just like you are, do one filter at a time just like the schematic. Then I figure out how to fold it up neatly, and I do the other filter the same way. Once I have that, I figure out what the common connections are, I try to put my ground points close together and my inputs from the amp close together. After much obsessing, and re-arranging, and double and triple checking the signal path with the schematic, I eventually get it all together. That's my method, and I'll admit, it's overkill after step one, but it's good practice and I enjoy a good puzzle now and again. The key is the signal path, if you lay it out and wire it up just like the schematic, it will work. Everything after that is just a matter of how pretty or compact you want it to be.
Thank you very much kind sir. I'm definitely going to do a separate board first. If I can move things around then that's wonderful. I thought it had to be like this lol. That tweeter schematic scares the living daylight out of me. I'll give it a go later tonight.
Electricity doesn't care if it needs to make a turn or two. You can reposition the woofer circuit components so they are much closer to each other, resulting in a much smaller board.
For example, pull that bottom resistor towards the left so it's right under the coil and perpendicular to the large cap (at a right angle). This will make your board half the size...LOL.
Sort of like this, but you can make it even tighter.
That is a lot of parts! The good news is, if you stick with it you can do it. I'm sure your next build will be much easier having tackled this one. It really is just a puzzle, like all puzzles it takes practice. Here's a few crossovers I've built, ranging from neat freak to compact, and a layout for one I did using two boards. Not trying to make your head spin, just giving you some ideas. The ground point seems to be something that first timers get confused about a lot, it is just a common connection between components. It can be one spot, or several places connected by speaker wire depending on the layout. Once you can wrap your head around how that works, the rest is just connect the dots. Then if you want it to look neat and tidy, fold it up and make it compact. I usually start just like you are, do one filter at a time just like the schematic. Then I figure out how to fold it up neatly, and I do the other filter the same way. Once I have that, I figure out what the common connections are, I try to put my ground points close together and my inputs from the amp close together. After much obsessing, and re-arranging, and double and triple checking the signal path with the schematic, I eventually get it all together. That's my method, and I'll admit, it's overkill after step one, but it's good practice and I enjoy a good puzzle now and again. The key is the signal path, if you lay it out and wire it up just like the schematic, it will work. Everything after that is just a matter of how pretty or compact you want it to be.
[ATTACH=CONFIG]36926[/ATTACH][ATTACH=CONFIG]36927[/ATTACH][ATTACH=CONFIG]36928[/ATTACH][ATTACH=CONFIG]36929[/ATTACH][ATTACH=CONFIG]36930[/ATTACH]
This may sound like a really dumb question, but with the connections on the back of the board and mounted against the cabinet. Wouldn't the connections get hot and become a potential fire hazard especially right up against the wood? That's my biggest concern, is a fire and always has been with anything electrical. I'm just probably over worrying about it lol. I was thinking about using little risers. Cut some little pieces of wood for each corner of the xover board to raise it from the cabinet.
When you do the tweeter circuit, do it in sections and then tie the sections together.
For example...
Working from left to right --
Make the T with the 7.5uf cap, 0.22mh coil and 20uf cap. That's section 1.
Do the LCR with the 2uf cap, 6ohm resistor and .05mh coil -- you will tie all three components in parallel with each other, sort of creating a single component. That's section 2.
Do the 4uf cap + 2ohm resistor. That's section 3.
The final 40ohm resistor is section 4.
Now just connect the sections, keeping in mind that section 2 (the LCR) will go in series between section 1 and section 3.
Electricity doesn't care if it needs to make a turn or two. You can reposition the woofer circuit components so they are much closer to each other, resulting in a much smaller board.
For example, pull that bottom resistor towards the left so it's right under the coil and perpendicular to the large cap (at a right angle). This will make your board half the size...LOL.
Sort of like this, but you can make it even tighter.
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