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Parts Express DIY C-Note Speaker Review

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amirm

amirm

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Thread Starter #43

Rick Sykora

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#47
port noise/resonance issue is apparent in spectrogram directivity plots in message #1 Very typical for rear ported 2-way speakers, nothing strange.

View attachment 59394
If you are right, this means the boss should literally "put a sock in it" :D

I will try as well, but as I posted earlier, my measurement equipment does not stack up anywhere close to Amir's!

@amirm can you try stuffing a sock in the port and, rerunning directivity test?
 
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Rick Sykora

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#48
Any chance that the 700Hz problem is a port resonance? Throwing together a quick model for the DSA135, withthe 1.5" port used in the kit I can get a port resonance in that region if I tune a bit low. Pretty nasty port resonance, though.
My Bassbox Pro model suggests the same port resonance, but even at 10 watts power, the vent velocities are quite low.
 
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xarkkon

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#49
In the midst of building a pair right now. Great review both showing measurements and how to solve it with EQ! Looking forward to more reviews from the DIY speaker thread :)

Hmmm... wonder if I should start finding gasket solutions for the woofer to solve the 700hz issue...
 
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#50
I built these a few years ago for my living area, then moved to Elac B6.2, then LS50's and now Magnepan MMG. The Elac's have been sold. The LS50's are in my bedroom and the C-Notes are my garage speakers with an Emotiva XDA-2 Dac, Lepai chip amp and a chromecast audio. I always liked the C-notes and I still do when I'm in the garage. Mine are finished in black with this "paint" and a nappy roller https://pittsburghpaintsandstains.c...rfacer-sealant-one-heavy-moderate-restoration
 

ROOSKIE

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#51
In the midst of building a pair right now. Great review both showing measurements and how to solve it with EQ! Looking forward to more reviews from the DIY speaker thread :)

Hmmm... wonder if I should start finding gasket solutions for the woofer to solve the 700hz issue...
Any hardware store will sell runs of foam gasket tape in various density and thickness. Also you can use rope caulk which is very common and often used for this sort of thing. Do not use to thick of foam or to much rope caulk, you will bend the woofer frame trying to compress the material.
You can also use a think bead line of quality silicone caulk. Let that dry for awhile (half dry ) and then mount the woofer.
By the way the paper gasket is not that bad and really is prolly not the problem, paper is a great material in certain gasket applications.
 

xarkkon

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#52
Any hardware store will sell runs of foam gasket tape in various density and thickness. Also you can use rope caulk which is very common and often used for this sort of thing. Do not use to thick of foam or to much rope caulk, you will bend the woofer frame trying to compress the material.
You can also use a think bead line of quality silicone caulk. Let that dry for awhile (half dry ) and then mount the woofer.
By the way the paper gasket is not that bad and really is prolly not the problem, paper is a great material in certain gasket applications.
thanks for the detailed reply, will check those out for sure!
 

mhardy6647

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#53
Heck -- now i want a pair of these... these are the ones that have been more or less perpetually out of stock, aren't they?
Actually, I probably don't really want a pair -- sensitivity is too danged low for the kind of power amplification available at my house :(
 

mhardy6647

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#54

Severian

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#55
I've used adhesive foam weatherstripping as a gasket on most of my builds and it works like a charm, including sealed subwoofers where the seal is critical.
 
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#56
Interesting review. I built the Overnight Sensations in 2013 and they cost the same price as the C notes now. I was curious as to the sound of the C Notes. Here is a link to my OS build if interested.
Overnight Sensation Build
I may buy the C-Note kit as a fun project but I have so many speakers already.
 

anmpr1

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#57
Only $100 bucks, my average bar tab, LOL.
That doesn't even tell us if you're much of a drinker. For a hundred dollars, if it's PBR in a can they have to carry you out. If your throwing down shots of JW Blue Label, that's a double on the rocks. LOL
 

Juhazi

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#58
My Bassbox Pro model suggests the same port resonance, but even at 10 watts power, the vent velocities are quite low.
Port velocity calc is done for tuning frequency, which is around 50Hz in this case. Port noise around 800Hz is "leakage" and typical for a straight tube in a box of this size - it is a "room mode" in depth dimension! Here is a good sim, dimensions set, just go down the page and press "Do it anyway"
https://amcoustics.com/tools/amroc?l=18&w=15&h=23&re=DIN 18041 - Music

It is extremely easy to take a nearfield measurement at reflex port mouth, like many many reviewers do, eg. Stereophile.
This 2-way is 10.6" deep (external) https://www.stereophile.com/content/totem-acoustic-signature-one-loudspeaker-measurements


Here my measurements of rear-ported 2-way speakers, one of them is a popular diy recipe speaker, guess which one?
er18 He2 A20 port nearfield 200ms 124.jpg
 
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Labjr

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#59
Kind of a messy assembly video. A PCB for the crossover would be nice. Or use terminal strips for electrical connections for a neat job.
 

dreite

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#60
I like the point-to-point wiring/soldering vice PCB. But, I would certainly not use Gorilla glue in that fashion to secure the crossover. What an effing mess, and almost impossible to repair/alter if the need arose.
I guess that makes the speaker Danny Richie proof though......so that's a good thing. :)

Dave.
 
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