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Parts Express DIY C-Note Speaker Review

MZKM

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#21
Score with equalisation. Not a trivial thing to compute, but in the modern world, one where just about every AVR has the ability to provide equalisation, not unreasonable. This would emphasise the balance across the polar response and de-emphasise flatness of response. But smoothness would still need to be included where it is not reasonable to tweak out irregularities. Something to ponder.
Yeah, I mentioned this elsewhere, but I just don’t see how to do this.

1) Not everyone uses the same EQ, REW has 10 bands, Audyssey XT32 has thousands, DIRAC has near infinite.

2) You ideally EQ the predicted in-room response and not the on-axis or listening window. However, we don’t really know how to compute how altering the PIR will effect those curves.

Looking at the DI curves and the normalized horizontal directivity is pretty much what you will have to look at to determine how easy it is to EQ a speaker.
 

Rick Sykora

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#22
Thanks Amir for the review!

For others who might be interested now that the results are posted, here are some additional notes from my build experience:
  1. If you have enough clamps and use wood glue (like Titebond), you will need more time to let glue set than it takes to build these. If I had more space, could glue each at the same time, While the glue sets, you can build the crossover and the port. Wood glue takes 24 hours to fully cure and the cabinets need to be done in 2-3 phases. So you can have unfinished speakers ready in the course of a weekend.
  2. As stated, I built these according to the instructions. I will note that the midwoofer could have a better gasket (I noticed some waveguide vibration just above the overlap). This may explain some of the 700 Hz ugliness that Amir's testing found. Next, would normally expect to use some dacron or other damping material for inside the cabinet. I added some to the one I have and did not find a measurable difference though. Finally, while the crossover components are way better then I expected for the price, the woofer coil wire is a bit thin (and so the coil has more resistance than I would prefer). I plan to try this and will report results on the build thread).
  3. Amir noted that his FR graphs do not correlate with others (including the ones I posted). I will investigate further, and post any findings. Keep in mind, my equipment cost about 1/1000 of his. ;)
  4. Decided to listen to the other C-Note I built as Amir does (one mono speaker). Am not trained and am in a much smaller room, but my impression aligns with his. Given low sensitivity, makes for an inexpensive nearfield monitor when paired with a low wattage amp.
Stay safe and healthy! :)
 
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astr0b0y

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#23
Thanks for the review.
What about magnetic shielding? I have but a few pairs of small DIY kits that typically get used as desktop computer speakers. What I have recently discovered is they are having a negative effect on hard drives located near them, likely due to lack of any shielding.
 

ROOSKIE

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#24
Thanks for the review.
What about magnetic shielding? I have but a few pairs of small DIY kits that typically get used as desktop computer speakers. What I have recently discovered is they are having a negative effect on hard drives located near them, likely due to lack of any shielding.
Not shielded.
 

Rick Sykora

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#25
How much consistency is there between these drivers?
In the build thread, I posted my REW response measurements for the unit I sent you and the one I kept. They track very closely. So this pair is consistent.

Overall one can experience inconsistency between the same model of drivers. Consistency is one of the differentiators for more expensive drivers (but not a guarantee). Version control is not a hallmark of the speaker industry. It is fairly common for a part to be changed without any change to the external part number.:(

I have found DIY kits that were designed years ago and no longer meet their measurements because a driver changed but continued to be supplied as though nothing was different.
 
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amirm

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Thread Starter #26
Thanks for the review.
What about magnetic shielding? I have but a few pairs of small DIY kits that typically get used as desktop computer speakers. What I have recently discovered is they are having a negative effect on hard drives located near them, likely due to lack of any shielding.
None comes with it but you can apply your own.
 

Rick Sykora

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#29
Thanks for the review.
What about magnetic shielding? I have but a few pairs of small DIY kits that typically get used as desktop computer speakers. What I have recently discovered is they are having a negative effect on hard drives located near them, likely due to lack of any shielding.
For another $38 over the C-Notes, the Overnight Sensations use a shielded woofer. It is an older deign and have no direct experience with them, but seem to get some good reviews. Hope this helps or maybe time to buy SSDs?
 

Xyrium

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#30
BTW, I think I prefer the plain MDF to that Bamboo'zle pair that you reviewed recently.

At $100 I suppose it doesn't have a long life expectancy before upgraditis kicks in, but I'd imagine frequent humidity over 40% would begin to reduce their rigidity, being MDF without a finish.

Edit: So, same anomalies as the RS162 with the xover distortion and 700Hz hump. Interesting.
 
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ROOSKIE

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#31
BTW, I think I prefer the plain MDF to that Bamboo'zle pair that you reviewed recently.

At $100 I suppose it doesn't have a long life expectancy before upgraditis kicks in, but I'd imagine frequent humidity over 40% would begin to reduce their rigidity, being MDF without a finish.

Edit: So, same anomalies as the RS162 with the xover distortion and 700Hz hump. Interesting.
The bare MDF will not get any wetter than a finished speaker. The inside is never finished and due to the port will be the same humidity as the rest of the space it is in. Plus even a sealed version would likely still have a similar air climate due to nothing really ever being that tight.
Plus most folks will finish it, I assume.
 

Xyrium

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#33
The bare MDF will not get any wetter than a finished speaker. The inside is never finished and due to the port will be the same humidity as the rest of the space it is in. Plus even a sealed version would likely still have a similar air climate due to nothing really ever being that tight.
Plus most folks will finish it, I assume.
Good point!

Veneer is cheap and not hard to apply
True as well!
 

Alice of Old Vincennes

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#34
BTW, I think I prefer the plain MDF to that Bamboo'zle pair that you reviewed recently.

At $100 I suppose it doesn't have a long life expectancy before upgraditis kicks in, but I'd imagine frequent humidity over 40% would begin to reduce their rigidity, being MDF without a finish.

Edit: So, same anomalies as the RS162 with the xover distortion and 700Hz hump. Interesting.
Humidity over 60 unlikely to affect MDF. 40 humidity is not high unless you live in the desert. MDF does not tolerate direct contact with water. Neither does veneer.
 

Alice of Old Vincennes

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#35
That is why you should not use MDF under roofing or flooring. Contractors do it all the time to save money. Evan in high end housing. I have seen big box interior $50 doors and plastic woodwork in $500,000 newer construction.
 

ROOSKIE

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#36
Been waiting for this one. I finished my pair about a week ago. I only have a few hours listening in.

I can concur that the bass is quite satisfying for a tiny system. Much deeper and fuller than the ELAC B5.2 & much more articulate and less on and off compared to the KEF Q150 & much flatter and a realistic sounding compared with Martin Logan LX16
I really like the bass (for what it is)

The midrange has a slight honky quality that sounds to me very slightly like cupped hands. This may be due to the horn/waveguide on the tweet. It bothered me at first and then I got used to it. Only an issue with vocals that I am familiar with. Mainly not a problem at all especially for the price.
The highs are quite smooth. Very nice detail. I did decide to cross them in front of me to get off axis a little as direct on axis I find them slightly hot.

I prefer the ELAC B5.2 at low volumes and maybe medium, after that it is all C-note. They sound great from medium upwards and I concur that these beg to be played loudly. No desire to turn them down like I have when I try to go loud with the ELAC 5.2 & the KEF Q150. The C-notes are easy to turn up!

Some issue aside, I prefer the C-notes ($160 with all parts and finished) in most ways to the ELAC b5.2 ($280retail /$150 BLK Friday) The KEF Q150 ($600retail /$300 sale) and the Martin Logan XL16 ($800retail/ $400 clearance)
If you listen mainly at low -medium volumes go for the ELAC B5.2 as they are just better there in every way except bass depth. Otherwise I see no reason to buy the Q150 and the ML LX16 pairs aside from the fact they are obviously ready to use.
These little speakers are great!

As a side note in comparison with my current budget faves, these in no way compare with my JBL Studio 530 speakers. Those are better for me in every way across the board.

EDIt* I did add the extra CAP on the woofer, not sure if it mattered but technically mine are slightly different than the pair here.
 

Alice of Old Vincennes

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#39
MDF is stronger than plywood Just can't use in if direct contact with water is expected. Not an issue with speakers. Unless your teenage son is left alone with your system.
 

BYRTT

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#40
Nice low cost diy build looking relative good, thanks to Amir publish review and all the work done behind the scene, will guess or imaqine reason for 760Hz resonance is one or a combination of below three points.
1) Port leaking
2) Rubber surround or non flush monted frame
3) So far in some of the test data it can look a scenario that directivity index takes a resonance hit in area where baffle loss for woofer goes from being a loss to a boost (see modeled blue trace below)

Here some overlays of technical curves for Parts Express DIY_C-Note:

Modeled_baff-diff_index.png

Modeled_baff-diff.png


Spin plus system impedance:

Advanced_spin.png
 
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