Parts Express DIY C-Note Speaker Review

[badspeakerdesigner]

There are probably a lot of other subjects more worthy of bated breath. I'll have to revisit this. I don't remember how much my mod improved things. I'll fire up the stock and modded version tomorrow and see whether it's worth the hassle.

You did state that it sounded better and it's just a few parts, seems like it'd be worth the look. Any updates?

 

[motomech]

This is somewhat "after the fact", but when Matt Grant designed the Nexus MT, which uses the same woofer and basicly the same box as the C-note, he had to revise the X-over to deal with an "unexpected peak" near 900hz and ended up doing another full set of measurements with a crossover fix for that peak.

Project NEXUS... A timbre matched family of Hi-Fi/HT speakers

Timbre matched family of Hi-Fi/HT speakers all based on the same midwoofer (Dayton DS135-8) and tweeter (ND28F-8). These designs came about from my...

www.hificircuit.com

 

[HighFutility]

Hey, everyone. I am deciding on my first DIY speaker builds, and these seem like the go-to choice. I have made five or so subwoofers and feel the c-note is a natural progression. I ordered the PCB off eBay with the optional NC - *Optional* - 0.22uF Capacitor to Reduce Woofer Cone Breakup - Dayton Audio DMPC-0.22. Is there anything else I need to know about the build? I have not ordered the kit yet, but would there be any meaningful difference if I built the cabinet out of 3/4 MDF instead of 1/2? I will probably line the enclosure with the half-inch adhesive-backed liner from PE.

Thank you all in advance.

 

[motomech]

Hey, everyone. I am deciding on my first DIY speaker builds, and these seem like the go-to choice. I have made five or so subwoofers and feel the c-note is a natural progression. I ordered the PCB off eBay with the optional NC - *Optional* - 0.22uF Capacitor to Reduce Woofer Cone Breakup - Dayton Audio DMPC-0.22. Is there anything else I need to know about the build? I have not ordered the kit yet, but would there be any meaningful difference if I built the cabinet out of 3/4 MDF instead of 1/2? I will probably line the enclosure with the half-inch adhesive-backed liner from PE.

Thank you all in advance.

Right now, P.E. is not even listing the .23 Ft flat-pack cabnets. I had heard a rumor that they were discontinuing most of the flat-packs, so, for now, they are not an option. The C-note cabs are nice and a smoking deal anyway.
I coat the inside of my cab.s with Water Putty. I mix it runny and rotate the enclosure around as it dries. If you want a heaiver coating, just do it again.
These stand-offs are handy for mounting the PCB;

Amazon.com

Drill the mounting holes in the MDF before assem.
Although clamps are nice, I've put them together w/ just painters tape and some weights.

 

[moonlight rainbow dream]

I think 3/4" mdf is on the verge of overkill for a small single 5" based speaker. I've built two pairs, one from the PE kit and one from scratch using mix of scrap 1/2" mdf+baltic birch plywood and parts from Solen. In both cases, I just added a single crossbrace, and I don't think the cabinets are noticeably colouring the sound though I don't have objective evidence of that with accelerometers, A/B listening tests, or whatnot.

If you do go with 3/4", you'll have to modify the dimensions slightly to maintain the same airspace. You might consider changing the box/port tuning to attain a flatter but less extended low frequency response versus the stock roll-off... depends on your room/application.

I find that I greatly prefer the sound of the C-note (particularly in a large or open layout room) with a shelf filter ~600hz -3db to make it full BSC, but you lose max output.

 

[HighFutility]

I think 3/4" mdf is on the verge of overkill for a small single 5" based speaker. I've built two pairs, one from the PE kit and one from scratch using mix of scrap 1/2" mdf+baltic birch plywood and parts from Solen. In both cases, I just added a single crossbrace, and I don't think the cabinets are noticeably colouring the sound though I don't have objective evidence of that with accelerometers, A/B listening tests, or whatnot.

If you do go with 3/4", you'll have to modify the dimensions slightly to maintain the same airspace. You might consider changing the box/port tuning to attain a flatter but less extended low frequency response versus the stock roll-off... depends on your room/application.

I find that I greatly prefer the sound of the C-note (particularly in a large or open layout room) with a shelf filter ~600hz -3db to make it full BSC, but you lose max output.

View attachment 341594
View attachment 341593

Nice build! I have a 3/4 inch mdf laying around and adjusted its size for the same volume. I kept the front baffle the same size, and I increased only the depth of the speaker. I was worried if I changed the front baffle size, I could get different directivity or screw something up. Do you have a build thread for your speakers? I was going to go the same route or entirely veneer mine with walnut. My only concern was if I painted the front baffle I would have a lip where the veneer sits. It looks fine, but my OCD would hyper-fixate on it.

 

[moonlight rainbow dream]

Nice build! I have a 3/4 inch mdf laying around and adjusted its size for the same volume. I kept the front baffle the same size, and I increased only the depth of the speaker. I was worried if I changed the front baffle size, I could get different directivity or screw something up. Do you have a build thread for your speakers? I was going to go the same route or entirely veneer mine with walnut. My only concern was if I painted the front baffle I would have a lip where the veneer sits. It looks fine, but my OCD would hyper-fixate on it.

Ah sorry no build thread. I'm pretty novice at woodworking. Maybe you can oversize the front baffle a smidge? Sounds difficult to get perfect. I was thinking of veneering the whole box, but I had already routed out the driver holes so it was too late.

 

[carbidetooth]

Ah sorry no build thread. I'm pretty novice at woodworking. Maybe you can oversize the front baffle a smidge? Sounds difficult to get perfect. I was thinking of veneering the whole box, but I had already routed out the driver holes so it was too late.

One can pretty easily veneer with driver cutouts already done, although it requires a handheld router and a couple of cutters. Specifically, I'd recommend:

51204 Solid Carbide Short/Flat Pilot for Dado Clean Out & Dado Cleaning Flush Trim 1/4 Dia x 1/4 x 1/4 Inch Shank x 1-Flute

Solid Carbide Panel Pilot Flush & Bevel Router Bits

www.amanatool.com

Spiral Flush Trim Down Cut

Spiral Flush Trim Down Cut

www.whitesiderouterbits.com

And if you'd like to see it being done, my epic video here might be helpful, even though a different speaker.

Your project looks nice. Your idea about overhanging the baffle a bit, then butting veneer into it and subsequently flush trimming could certainly be viable.

 

[HighFutility]

One can pretty easily veneer with driver cutouts already done, although it requires a handheld router and a couple of cutters. Specifically, I'd recommend:

51204 Solid Carbide Short/Flat Pilot for Dado Clean Out & Dado Cleaning Flush Trim 1/4 Dia x 1/4 x 1/4 Inch Shank x 1-Flute

Solid Carbide Panel Pilot Flush & Bevel Router Bits

www.amanatool.com

Spiral Flush Trim Down Cut

Spiral Flush Trim Down Cut

www.whitesiderouterbits.com

And if you'd like to see it being done, my epic video here might be helpful, even though a different speaker.

Your project looks nice. Your idea about overhanging the baffle a bit, then butting veneer into it and subsequently flush trimming could certainly be viable.

Nice video, question for you. What do you use to flush trim when the depth is very minimal?

I bought a new bit only to realise for shallow-depth inlays I won't be able to flush the trim.

Picture for reference.

Edit: Can I router into the tweeter waveguide to flush mound the bass driver? Has anyone done this ?

 

[carbidetooth]

Nice video, question for you. What do you use to flush trim when the depth is very minimal?

I bought a new bit only to realise for shallow-depth inlays I won't be able to flush the trim.

Picture for reference.

Edit: Can I router into the tweeter waveguide to flush mound the bass driver? Has anyone done this ?

I use the first cutter I listed. I haven't encountered a tweeter rabbet that wasn't deep enough to accommodate the pilot bushing on it. Bear in mind that the guide bearing (bushing) is actually the shank itself so one does not want to dwell in any one spot in the tweeter rabbet but rather keep the cutter moving. Practice on scraps is always a good idea.
I've imagined doing what you suggest. My first step would be to see if I could accomplish the woofer rabbet outer diameter with a bottom bearing rabbeting cutter and right size bearing. If so, I'd cut the rabbet first, then temporarily install tweeter and run the same cutter at same depth to cut tweeter frame/flange. If I couldn't achieve the desired diameter that way, I'd build a jig and probably use a top bearing guided cutter to accomplish same thing. There are other ways, but these would be simplest with exisitng driver holes.
FWIW, I have mostly gotten away from straight cutters like the lower on your photo in favor of spirals. Straight cutters chop while sprials remain engaged. Much smoother and easier to control.
So we don't completely derail this thread, you can PM me here or comment in video or my email addy which is in the description on all my vids.

 

[Rick Sykora]

Nice video, question for you. What do you use to flush trim when the depth is very minimal?

I bought a new bit only to realise for shallow-depth inlays I won't be able to flush the trim.

Picture for reference.

Edit: Can I router into the tweeter waveguide to flush mound the bass driver? Has anyone done this ?

Yes, others have done. You would need a rabbeting bit to deepen the woofer recess. The tweeter cutaway can be traced and, after carefully covering the dome with tape, trim the plastic with a dremel. Always good practice to leave some excess and file down the edge for a nice joint. Even if you mess up slightly, gaps can be filled with black silicone seal.

 

[HighFutility]

Yes, others have done. You would need a rabbeting bit to deepen the woofer recess. The tweeter cutaway can be traced and, after carefully covering the dome with tape, trim the plastic with a dremel. Always good practice to leave some excess and file down the edge for a nice joint. Even if you mess up slightly, gaps can be filled with black silicone seal.

Thanks for your input.

 

[automojo]

Just my experience-with the powered C Sharpe.
Samame kit-just includes an onboard Bluetooth amp.
This enclosure needs effective damping-as the designer indicates.
Part of this is the AL cone Designer woofers as well.
The 1-1/4 Sonic Barrier-3 layer solves this.
The voids around the port, use acoustic stuff.
Cut smaller pieces to fit around the amp/terminals.
Small 1 1/2 behind the woofer and over crossover.
IMHO a 2uf for the tweeter also is huge.
Audyn Cap Plus, or Clarity CSA.
I have made 4 sets of these-I like the Cap Plus better with this tweeter.
Don't freak out about the 1-1/4-this solves your (audible) port AND enclosure resonance problem.
Sure it adds to the cost-but might as well do it right-the first time!!
These 2 simple mods really clean up the bass/midbass response-as well improve the tweeters response.
This tweeter deserves a decent cap.
In the past-I have used the older Dayton 10 and 8" Al cones (silver one's) before with excellent luck (these worked better in sealed enclosures).
They all needed very effective enclosure/backwave damping to get the best results out of them.
From what I've heard-it's typical with AL cones.
Once you do this-the end result is deep, tuneful yet very low distortion bass.
Well worth the effort IMHO.

 

[pjug]

Just my experience-with the powered C Sharpe.
Samame kit-just includes an onboard Bluetooth amp.
This enclosure needs effective damping-as the designer indicates.
Part of this is the AL cone Designer woofers as well.
The 1-1/4 Sonic Barrier-3 layer solves this.
The voids around the port, use acoustic stuff.
Cut smaller pieces to fit around the amp/terminals.
Small 1 1/2 behind the woofer and over crossover.
IMHO a 2uf for the tweeter also is huge.
Audyn Cap Plus, or Clarity CSA.
I have made 4 sets of these-I like the Cap Plus better with this tweeter.
Don't freak out about the 1-1/4-this solves your (audible) port AND enclosure resonance problem.
Sure it adds to the cost-but might as well do it right-the first time!!
These 2 simple mods really clean up the bass/midbass response-as well improve the tweeters response.
This tweeter deserves a decent cap.
In the past-I have used the older Dayton 10 and 8" Al cones (silver one's) before with excellent luck (these worked better in sealed enclosures).
They all needed very effective enclosure/backwave damping to get the best results out of them.
From what I've heard-it's typical with AL cones.
Once you do this-the end result is deep, tuneful yet very low distortion bass.
Well worth the effort IMHO.

I hadn't heard of the C Sharp. It looks like it is just a C-note with Lepai plate amp? The C-note produces a lot of peaking in the frequency response curve with this kind of Class D amp, so isn't that a bad combination? Or is the crossover different to allow it to work? In the Parts Express C-sharp literature I get the impression that the frequency response they show is for the C-note, and they just assume it would be the same with any amp.

 

[automojo]

I hadn't heard of the C Sharp. It looks like it is just a C-note with Lepai plate amp? The C-note produces a lot of peaking in the frequency response curve with this kind of Class D amp, so isn't that a bad combination? Or is the crossover different to allow it to work? In the Parts Express C-sharp literature I get the impression that the frequency response they show is for the C-note, and they just assume it would be the same with any amp.

I don't hear any peaking what so ever.
Very smooth and spacious speaker sounding speaker IMHO (with the above mods).
As far as Class D go-I'm not a expert-these little speakers would be the only ones I have running D's.

But these sound very good for what they are.
And they are under $300-so...they aren't going to sound like-for example my Primaluna/Van ALstine all tube combos powering Infintiy RSiiia's-2nd PL/VanAlstine combo powering Mojo modded ESS AMT3's.
Nor do they sound as good
as my daughters P/E Hitmakers (w/Clarity CSA's, and Dayton DPR resistors) driven by a 1st Gen Peachtree Decca-in their little studio.

But again-with the right caps, and damping the C Sharps sound excellent IMHO for what they are.
Frankly the Dayton cap seriously limits the performance potential of this tweeter, and possibly a cause of some of the "bright" complaints (to me the Daytons usually sound flat/one dimensional, and closed in.
They aren't the best for mid/tweets. I stopped using them years ago for this very reason.
The caps and damping are only enhancing what they are.
Not changing the basic design/goals
.
When I hear them-I'm not wishing for anything.
Just enjoying the music.
IMHO that's where they hit far and above their modest price tag-plus them being self contained is a huge plus for many situations that the 4 pair I have constructed (I have one pair myself-the other for friends) find themselves in.
Thats why I built four sets.
If I thought they sounded peaky, and generally sucky-that wouldn't have happened!

 

[pjug]

I don't hear any peaking what so ever.
Very smooth and spacious speaker sounding speaker IMHO (with the above mods).
As far as Class D go-I'm not a expert-these little speakers would be the only ones I have running D's.

But these sound very good for what they are.
And they are under $300-so...they aren't going to sound like-for example my Primaluna/Van ALstine all tube combos powering Infintiy RSiiia's-2nd PL/VanAlstine combo powering Mojo modded ESS AMT3's.
Nor do they sound as good
as my daughters P/E Hitmakers (w/Clarity CSA's, and Dayton DPR resistors) driven by a 1st Gen Peachtree Decca-in their little studio.

But again-with the right caps, and damping the C Sharps sound excellent IMHO for what they are.
Frankly the Dayton cap seriously limits the performance potential of this tweeter, and possibly a cause of some of the "bright" complaints (to me the Daytons usually sound flat/one dimensional, and closed in.
They aren't the best for mid/tweets. I stopped using them years ago for this very reason.
The caps and damping are only enhancing what they are.
Not changing the basic design/goals
.
When I hear them-I'm not wishing for anything.
Just enjoying the music.
IMHO that's where they hit far and above their modest price tag-plus them being self contained is a huge plus for many situations that the 4 pair I have constructed (I have one pair myself-the other for friends) find themselves in.
Thats why I built four sets.
If I thought they sounded peaky, and generally sucky-that wouldn't have happened!

I didn't realize that the plate amp is filterless (or maybe uses minimal output filter). So it won't then have the peaking issue with the C-note. I shouldn't have assumed without digging a little.

 

[automojo]

I didn't realize that the plate amp is filterless (or maybe uses minimal output filter). So it won't then have the peaking issue with the C-note. I shouldn't have assumed without digging a little.

OK-guess that explains it....
Regardless I stand by the 2 variations from the standard kit recommendations.
1). 1 1/4 Sonic Barrier lining the walls
2) replace the 2.0uf tweeter cap with a higher quality cap
Sugg: Clarity CSA, or Audyn Cap plus.
The Mundorf AL Evo Oil would also most likely be a good choice as well.