Comments on Profile Post by ultrabike

53 Hz for a 4.5 litter enclosure is awesome. ND140 (Avia like design) can do much lower, but it would not be a monitor.

Yep, I also felt it was quite a clean and nice sounding driver, not that you can really judge in the finished speaker

I do wonder how the C-Note compares though as it's a bit bigger

I would have to look at their cross over design. There might be other options for tweeter. Tweeters with a nice face plate remove diffraction issues. In fact @maverickronin found about a new 1/2" tweeter that is awesome sauce. But may need support from a 2" mid tweeter. Unless the B4N can be crossed sufficiently high up.

The C-Note may trade low frequency extension for more efficiency in a similarly sized box. I would get the OS just cuz I appreciate low frequency extension on a small monitor. The tweeter of the OS appeals to me more as well. The C-Note uses probably a efficient design. But don't care that much for controlled dispersion as I do for large sweet spot.

In a nutshell. To me the C-Note is a more efficient, controlled dispersion version of the OS, with less bass... but still good bass.

Yep, that tweeter really looks awesome. Low inductance, too.
Well, the C-Note is tuned a bit deeper and leaner it seems. But even I can't deny that small with good extension has its uses. The speakers I'm listening to right now are 4", ~82db/2.83V, about 9L speakers tuned to 33Hz set up with a shit ton of room gain

The lowest room mode at 25Hz is about 3db down from the midrange level that way (but there's also a deep room suckout at 34Hz). The downside is something like 10-20% distortion at 80-85db in the subbass. Stil, I realized I can't go without at least 40Hz extension and I also didn't want a sub

Wait, how big is the enclosure of that 33 Hz tuned speaker?
BTW the OS is actually pretty impressive. I would get that one if I could afford a larger speaker, not the C-Note. Although I hate non-black drivers.

Outer dimensions are 18x26x36.5cm. It's my prototype of the Slim Classic GR that @Jeb built with a different driver. Almost half the volume is lost from 18mm wall thickness, driver, port, etc. No crossover inside the speaker yet as that's done electronically, but I doubt I will ever be able to fit that inside with the EQ I'm using right now.

I'm using one of the white Aucharm 4" drivers with a whizzer cone because I wanted a slightly bright driver with a whizzer cone for better dispersion. I hope I can improve the driver FR with some coatings. I also want to make it taller and move the driver higher, closer to ear height and use thinner wood panels... I also need to experiment more with damping. Still far from being done, but it already shows promise.

Ran some numbers for the OS. The build works. It has a bit of a bass hump and the extension goes down to about 53 Hz. However, that woofer can go down flat to 36 Hz with a larger enclosure. In fact, the OS seems like a compromise to keep the size small.

The OS calls for a 4.5 litter enclosure. The optimal is 10.5 litters. That being said, the designer played nice with the port to give a very nice response down to the target 53 Hz corner frequency. Given the size, that is very respectable IMO. The cross-over works well too.