C-Note MT Bookshelf Speaker Kit Pair & Other kits

[ronk]

You will need to strip them down to bare. Water based poly doesnt work well over the oil base.

Thanks,

Ok, no water based poly over oil based poly. Maybe when the weather is nice, I might go to my deck (or garage) and add a second layer of the stinky minwax stuff. Or just leave the OS with almost bare wood.

Can I just use vinyl wrap over MDF for my C-Note. I am thinking about easy and vinyl wrap without prep will be easiest. Next will be elmers glue cover and then spay stone texture or elmers glue over vinyl.

[isaeagle4031]

Sure you can do vinyl. It does need prep though. The surface needs to be flat and smooth. Any cut edges or end grain needs to be sealed. A coat or 2 of wood glue works well. Let it dry completely then lightly sand with 220 grit to remove any fuzzies.

[Evan Steeves]

Or use cheap mattress foam. One queen mattress foam works for many loudspeaker builds. As the C-Note is bass reflex, lining the walls might be better than poly fill throughout the cabinet.

Was only going to put some polyfill at the bottom, similarly to my Amigas. I usually treat the two (lining walls and polyfill) as seperate items. Just not sure why kit didn't include acoustic foam, if it might be roequired - perhaps for cost reasons?

[ronk]

Probably for cost reasons, they did not include foam, and more importantly, a notch filter to deal with any potential aluminium driver breakup. According to Chris P, the designer, he crossed the woofer at 3 k so that the breakup is 20+dB below reference to reduce cone breakup effects. This is so we can get the deal of one C-note aka hundred bucks. Foam and additional crossover parts will raise price to above 100 bucks. Foam and fill are stuff I can easily add and is no biggie. I would prefer Baltic birch plywood as that is nicer and does not smell like mdf, but I suspect Baltic us more expensive than mdf.

My C-note arrives today.

[Evan Steeves]

Probably for cost reasons, they did not include foam, and more importantly, a notch filter to deal with any potential aluminium driver breakup. According to Chris P, the designer, he crossed the woofer at 3 k so that the breakup is 20+dB below reference to reduce cone breakup effects. This is so we can get the deal of one C-note aka hundred bucks. Foam and additional crossover parts will raise price to above 100 bucks. Foam and fill are stuff I can easily add and is no biggie. I would prefer Baltic birch plywood as that is nicer and does not smell like mdf, but I suspect Baltic us more expensive than mdf.

My C-note arrives today.

Hey Ronk, that makes sense.

As I am not yet at the stage of crossover design (my next learning objective, but after I finish my part-time MBA in 2 months I will actually have time for this), I am wondering if you will be adding a notch filter to your crossovers for these? It would be easy enough to obtain parts locally and probably not too expensive either. If it isn't worth the trouble and they perform well, I may skip this step. Their main purpose is surround duty, with occasional mono output for hosting guests.

I can get some foam locally at addison electronic store, I may buy a few pieces for good measure. I assume most PSA 1/2'' foam would have similar effect? This is the one I have available, looks simple and inexpensive;
https://addison-electronique.com/mou...nte-17643.html

In my case I'll be veneering all my speakers with walnut veneer, as they are all raw MDF right now. Only annoyance is the baffle roundovers, which are too small to vener; will probably just router the roundovers out after assembly, buy walnut quarter rounds to replace, and veneer the rest.

[ronk]

One cannot just add a few parts for a notch filter. I suspect the entire low pass (and maybe even the high pass) will have to be redone to have a notch filter. At 1 Centum, I can live without the notch filter. I tend to listen to youtube a lot and the sound quality of youtube is often so mediocre that speakers do not matter much. My reference speaker sounds terrible with most youtube music -- too much resolution and lousy old Roku. I am not going to try to simulate the crossover based on driver files from PE with software that I don't have to design a crossover that will probably be worse than the current stock. I am building this speaker because I like building speakers as a hobby. I am thinking about another build -- Denova .23 cu ft cabinet with TB w5 2143 bamboo paper. My main problem is cutting the holes for the drivers (and maybe the port) as there are no holesaws that size and I do not have a router nor space for a router.

My C-Note is still on the UPS truck somewhere. Anyway I will be home much later tonight so I will see it when I get home.

[Evan Steeves]

One cannot just add a few parts for a notch filter. I suspect the entire low pass (and maybe even the high pass) will have to be redone to have a notch filter. At 1 Centum, I can live without the notch filter. I tend to listen to youtube a lot and the sound quality of youtube is often so mediocre that speakers do not matter much. My reference speaker sounds terrible with most youtube music -- too much resolution and lousy old Roku. I am not going to try to simulate the crossover based on driver files from PE with software that I don't have to design a crossover that will probably be worse than the current stock. I am building this speaker because I like building speakers as a hobby. I am thinking about another build -- Denova .23 cu ft cabinet with TB w5 2143 bamboo paper. My main problem is cutting the holes for the drivers (and maybe the port) as there are no holesaws that size and I do not have a router nor space for a router.

My C-Note is still on the UPS truck somewhere. Anyway I will be home much later tonight so I will see it when I get home.

aah, I see, good insight, thanks for sharing.

I just bought an awesome DeWalt router kit, with both fixed base and solid base attachments, on sale at Lowes canada. One of the best tools I own...was so incrediibly useful in building my sunflower center channel. Also didn't realize how easy it could be to do intricate things with a router (provided you plan properly of course). Going to use it this time to flush mount the port tube on the back for a nice clean finish.

Good luck with your build! please post pics when you get the parts, and pics of your build as well! Hopefully you are able to find the right tools. When in doubt - break out the jigsaw! Lips will hide the hole anyways.

[wogg]

Dang... this kit is a deal. I have a sort of similar design on paper with a DS175-8 and ND28F-6 that comes in at $200 for the build. The drivers only account for $30 in additional cost total, and my crossover is equivalently simple second order on both.

As much as I'd like to with my own design, it's really hard to compete with that cost.

[Evan Steeves]

Dang... this kit is a deal. I have a sort of similar design on paper with a DS175-8 and ND28F-6 that comes in at $200 for the build. The drivers only account for $30 in additional cost total, and my crossover is equivalently simple second order on both.

As much as I'd like to with my own design, it's really hard to compete with that cost.

Precisely why I indulged!!!

[Chris_Perez]

One cannot just add a few parts for a notch filter. I suspect the entire low pass (and maybe even the high pass) will have to be redone to have a notch filter. At 1 Centum, I can live without the notch filter.

Hey Ron,

When I designed this kit I just knocked the resonant peak down and didn't even try to completely eliminate it. I was just playing with the design files and discovered that just adding a 0.22 uF capacitor in parallel with L2 should pretty much kill the peak all together without affecting anything else. I am going to try it on my pair at home to make sure there are no adverse affects, but it might just be that easy.

-Chris P

[jhollander]

Chris you might consider adding a series resistor with that cap as you would have a capacitance load to ground.

[wogg]

Chris you might consider adding a series resistor with that cap as you would have a capacitance load to ground.

It's a very small capacitance, in order to get under 8 ohms you'd have to be up over 90kHz.

[ronk]

Hey Ron,

When I designed this kit I just knocked the resonant peak down and didn't even try to completely eliminate it. I was just playing with the design files and discovered that just adding a 0.22 uF capacitor in parallel with L2 should pretty much kill the peak all together without affecting anything else. I am going to try it on my pair at home to make sure there are no adverse affects, but it might just be that easy.

-Chris P

Yes Chris, please let us know how that sounds. If it sounds better, I will delay the build and order two 0.22 uF capacitors to break up the aluminium sound. Both my DIY speakers with aluminium midbass; the Overnight sensation with the Hivi drivers and my model 2 sassy with seas aluminium drivers have the .22 caps in parallel with the series inductor to "kill" the aluminium sound. I did think about trying that approach, but thought to myself, nah, it cannot be that easy.

One additional question for Chris is, "How important is the .205 " 16-14 Female Disconnect? I forgot to order the female disconnects. I have some leftover 0.110 (so I don't need that size) and some .25. Could I use the .25 disconnect in place of the .205 disconnect?"

My C-Note arrived today with a few extra stuff but no binding post. Now I need to wait for the binding post and decide whether I want to have the .22 cap in parallel with the L2. If so, I will have to wait until I can order $100 from PE to get free shipping. I also have to decide on cheap vinyl finish, better viny stuff, paint (but with priming), or stone finish (which looks cool). I have an idea for the next build -- a 4 or 5 inch Tang Band full range in a box. If I go with the 5 inch Tang Band, I will need a jig, while I can use a Holesaw for the 4 inch TB. But the 4 inch TB bamboo paper with neodymium is very pricey. The 4 or 5 inch TB bamboo paper drivers with ferrite magnet is a lot cheaper.

[wogg]

Yes Chris, please let us know how that sounds. If it sounds better, I will delay the build and order two 0.22 uF capacitors to break up the aluminium sound. Both my DIY speakers with aluminium midbass; the Overnight sensation with the Hivi drivers and my model 2 sassy with seas aluminium drivers have the .22 caps in parallel with the series inductor to "kill" the aluminium sound. I did think about trying that approach, but thought to myself, nah, it cannot be that easy.

The parallel LC in line with the woofer creates a really good tank notch filter, I prefer to build that in my crossover designs myself (though I'll admit I'm relatively inexperienced in bringing these to reality). The trick is that it will throw the phase and therefore the summed response and reverse null off if the tank frequency is close to the crossover frequency. In this case, it sounds like the breakup is far enough above the crossover frequency to not have too much of an effect.

One additional question for Chris is, "How important is the .205 " 16-14 Female Disconnect? I forgot to order the female disconnects. I have some leftover 0.110 (so I don't need that size) and some .25. Could I use the .25 disconnect in place of the .205 disconnect?"

Can't speak for Chris, but the disconnects shouldn't be that important. A pair of pliers will let you adjust the grip of the connector and as long as they're getting some metal and tight your connection will be fine.

[ronk]

OK, a .22 cap in parallel with L2 might trap the breakup of the woofer without any adverse effects to the rest of the low pass filtering. I am waiting for my binding posts to arrive before deciding whether I am going to buy some. 22 caps to try it out.

I ran to woofer full range baffleless to see how the sound and to break them in. They work.