Parts Express DIY C-Note Speaker Review

[sheninat0r]

Curious how you did the flush modification? Trim the tweeter diffuser but then made another round cut into the existing face board with a router?

I followed ChrisP's suggestion from earlier in the thread: I mounted the tweeter and cut the cabinet and waveguide together in a single pass.

 

[Weeb Labs]

I have to wonder as to the effect of that lip around the ND25's waveguide upon diffraction. Probably nothing desirable.

 

[Northa40]

I just finished building a pair of these, and I'm suitably impressed by the sound for the size and cost. This was my first speaker project and first attempt at veneer, very happy with how they turned out!

I used the 0.22uF capacitor, added a dowel between the side panels, put a bit of stuffing in the cabinet, and recessed the woofer to make the front panel flush.

Those look awesome! Did you use a jig with the router or did you place a cut out in the baffle hole to center the router?

 

[sheninat0r]

Those look awesome! Did you use a jig with the router or did you place a cut out in the baffle hole to center the router?

I got lazy and used a 1/2" rabbeting bit, which left a slightly oversized recess (~1/32" all around the woofer). If I were to do it again, I'd probably plug the hole and use a circle jig, or make/3D print some bearing spacers to get a perfect-sized rabbeting bit between 7/16" (too small) and 1/2" (too big). I ended up printing some thin black spacer rings to fill in the gaps left by the router.

 

[destase]

I’ve seen several recommendations to put damping material in the bottom of the cabinet. If the crossover is also mounted to the bottom panel, does that mean the crossover can be covered up without overheating?

 

[Northa40]

I always cover the crossover with a little insulation and have never had an overheating situation. I built a pair C-note speakers and covered the crossover with foam and lined the walls with sound deadening asphalt and felt. It amazes me just how much bass these things are capable of. I did not use the port extension.

 

[Head_Unit]

does that mean the crossover can be covered up without overheating?

Yeah, a crossover really just shouldn't get hot. The only way I can really think of would be a too-small inductor in series to the woofer.

 

[30 days]

That's impressive for $100.00 delivered to the door.

Well, like everything else, the price has went up, now $150-(last time I checked). I build my c notes, used some oak veneer from Menards, they are great. And they can handle some power.

 

[30 days]

I've been enjoying mine for a couple of years now on my desktop. Great all around. Very similar to the JBL 3-series, though without the godlike constant directivity. Great bass down to ~40hz in a typical desktop setup where you have a wall behind them.

Anywhere from... let's say 3 to 10 hours? Depends on if you're familiar with basic soldering, and how fancy you go with the finish.

There are some drying steps involved so it wouldn't be 3-10 consecutive hours

At the most basic level, you could sand the MDF and spray paint it. Or throw some chalk paint on there and then give it a wax seal rub. Or at the high end you could go for true furniture quality veneer finish, or get crazy with automotive paints and 1200grit sandpaper.

The assembly video Amir linked to above should give you a good idea what you're in for. On the product page, PartsExpress also gives you a PDF manual that lists additional supplies (wood glue, etc) that you'll need.

When I build mine, I had a hernia, then had surgery, now I'm fine. Anyway, I had to do a little work at a time, so I was not in a hurry. I am very happy with them, I keep them covered when not in use. They look and sound GREAT!

 

[JohnBooty]

When I build mine, I had a hernia, then had surgery, now I'm fine. Anyway, I had to do a little work at a time, so I was not in a hurry. I am very happy with them, I keep them covered when not in use. They look and sound GREAT!

That's great to hear! I'm glad they turned out so well and even more importantly: I'm glad your health is better.

 

[30 days]

Shows how much I know about speaker design that I missed the obvious fact about it being a full wavelength! Thanks for the suggestions.



@Winkleswizard posted results of testing with the damping and shortened port this morning, and it seems that with both tweaks, the resonances disappeared. Sounds like just lining the bottom half of the the interior with dampening might get rid of the resonances without effecting the base response, addressing the only criticism that Amir had in the listening tests.

I used parts exp. acoustic stick on foam for the sides, and layers of carpet foam for the top. How do I know if there are resonances?

 

[30 days]

I'm curious about the Swan/Hivi 3-way kit there. How do they compare with everything else you have ? (its subjective no doubt but its really about impressions at this point, whatever information is useful)
And what sort of amplification you used on them ?

So, what does the change in capacitor add the the sound?? Please be patient, I am not that knowledgeable. And should I make this upgrade???

 

[30 days]

Finally put together my first diy speakers, the C Notes! Yay! Really enjoyed the build process, but made a whole truck load of mistakes.

What's everyone using to run them with? I'm thinking of getting a desktop amp to hook them up to my PC setup, replacing my Edifier 1280s.

View attachment 60433

I am powering my C notes with Nikko trm 750, the c notes and my vintage amp seem to work well together.

 

[30 days]

Can you temporarily move them way out from walls? Or outside or in a garage or something? How do they sound then? And what do you mean by muddy?
- Because if too strong/boomy then you could stuff the rest of the enclosure with fiberglass which will absorb more midrange, cause the enclosure to appear somewhat larger to the woofer (due to modifying the heat curve of the expanding/contracting air), and thus effectively lower the port tuning a bit. Those things would reduce boominess a bit, though the room will tend to be the dominating factor.
- If by "muddy" you mean they sound distorted, tell us more: what are you playing? How loud? How much are the woofers visibly moving? Are you certain your amp is not clipping?

Meanwhile, the finish looks GREAT!! How hard was that to do? I have never veneered. Is there a seam on the back? Or the veneer just goes on the sides? How did you cut the top and bottom?

Mine are oak veneered, that I got at menards, I stained and varnished them. I would post a picture, but not sure how..

 

[30 days]

I would certainly hope so!

I checked, the revel m22 speakers sell for $2200.00

 

[30 days]

In case this has not already been mentioned, the $14 Dayton Audio ND25FW tweeter used in these speakers has absolutely no business performing as well as it does.

Incredible value for money.

View attachment 166220

View attachment 166222

So, the tweeter in my c note speaker sells for fourteen (14) dollars, lol, amazing!!

 

[30 days]

That's great to hear! I'm glad they turned out so well and even more importantly: I'm glad your health is better.

THANKS!

 

[motomech]

I did a makeover of the C-note.
Basicly, I lopped the ND25 tweeter off the wave guide and siliconed a ND28F-6 in it's place. It fits exactly the same and one would be hard-pressed to see any difference once installed.
Then I installed the cross-over that Matt Grant designed for his NEXUS series of speakers.
He describes it here;

"The crossover is about 2100hz, fairly low but the ND28 handles it well without any rise in distortion. .....I chose to add a decent amount of BSC into these designs which gives them a very full sound. The midrange is very clear but not overbearing, and the treble smooth without sounding dull. Bass is again very good for such a compact speaker."​

That's a very accurate description of what I ended up with. Everything else is stock C-note w/ the box lined w/ light duty felt sheets and stuffed rather full of poly, I can detect no resonances and I can only summize the C-note's 700Hz. nastiness is a result of it's low-cost X-over forcing the woofer higher that it likes and being unable to tame the resulting vulgarities and much less to do w/ box construction or diamentions, vent port, etc.
I wasn't sure how adding the wave guide to the mix would work out, but so far I'm liking the results, the sound is large and full enough for me to rotate them into a main speaker slot.
All this comes at a cost w/ the tweeters and components for the complex X-overs coming to about $200 and the X-over won't go thru the woofer opening(I split it and put the tweeter board inside and mounted the woofer board on the backside.
It may seem crazy to spend $200 on a $140 kit, but if you have a nicely finished pr. of C-note that are gathering dust, I think it would be worth it. Heck, even if one was starting fresh, a total of $340 isn't bad. They seem to be on par w/ my other low-cost DIY bookshelves, like the original Aviatrix or Paul Carmody's The Girl from Ipanema.
I guess the test will be longer-term listening to see if I can live a pr. of mini-tweeter mains, something I haven't been able to do yet.

 

[badspeakerdesigner]

Hi ASR, made an account to try and see if I could get some answers on my cnotes. I've got a huge HF shelf in my speakers that I can't seem to figure out, the speakers sound quite bright. PE actually offered to measure the speakers in house to see if they are performing within spec. On their end they indeed show the speaker to be performing on par with their measurements, you can see that here. They also took the speaker apart to verify that the crossover was wired up and behaving appropriately. Red is my speaker, black is theirs, bass difference is from using a different port tuning.

After they measured the speaker, I went ahead and tried to troubleshoot my measurement tools. PE offered to replace my EMM6 microphone and I took them up on that offer. Unfortunately it would appear that the mic was fine and my measurements show the same HF shelf. It's worth ignoring the jagged low end as I didn't have the speakers far enough off the ground and they were on quite thick stands. I'm mostly concerned with the top end.

I didn't have any other speakers with third party data to compare to (just some Amiga DIY speakers) so I borrows a kali lp6 v2 from a friend. Here is the quick measurement of those which doesn't show a HF shelf. I was hoping this would rule out errors in my mic, pre, and the various amplifiers I had swapped in and out when measuring the c-notes.

Here is both the speakers line up in REW to account for my differences in scaling between the two graphs. Blue is cnote red is Kali.

At this point I'm at a loss. My ears certainly seem to agree that the HF is quite boosted on my c-notes and applying some corrective EQ brings them closer to neutral and a more correct sound, but it's not shown on the in house measurements PE took.

 

[mcdn]

What’s the physical measurement setup (audio interface, mic distance and position, location of speaker in room, size of room)?

And what’s the REW setup - gating, windowing, etc?

TBH the Kali measurement looks a bit odd as well, it shouldn’t slope up from 2.5kHz