Wow! Mind sharing a photograph of that epic collection? :ksc75smile:

Ah, I see. I was curious because I read this off Wikipedia: "First-order filters are considered by many audiophiles to be ideal for crossovers. This is because this filter type is 'transient perfect', meaning it passes both amplitude and phase unchanged across the range of interest. "...

Doesn't phase shift only occur in crossovers that are greater than first order? So theoretically if you only used 1st order crossover networks, could you avoid phase issues?

Yup, not going to use the seam on the side of the driver. Instead I'll etch onto the lid and attempt to create my own seam that I can continue to work at until I can pull the lid off.

I used a razor to remove the spout from an SWFK and then also used the razor to split the two halves of the SWFK into two WBFK’s. I’m planning on using a razor to etch lines into the roof and wear away at the etched lines of the WBFK so I can try making my own makeshift TIA.

Found a knock off of 64 Audio's APEX module for sale on Taobao: https://world.taobao.com/item/613205571532.htm

I found this great thread which has a great deal of information on couplers. Also page 7 has links to a number of couplers as well. https://www.head-fi.org/threads/audio-measurements-on-a-headfi-budget.893084

I 3D printed a part I designed that accepts a 1.5mm outer diameter, 1mm inner diameter tube, then I used blue tack to seal the part to the coupler. I am using the Vibro Labs Veritas, so it’s not an actual IEC711 coupler, but it’s good enough for initial measurements. I should buy a proper...

Could someone with an IEC60318-4 compliant coupler share their measurement of a Knowles CI-22955 driver. Please use an 8mm long, 1mm inner diameter tubing with no filters from the driver to the coupler. If you have a different recommendation for tube length from balanced armature to coupler...

One thing we could do is use a common driver as a point of reference. For example, anyone that wants to contribute to the database would need to have a measurement of TWFK-30017 unfiltered with a 10mm long 1mm inner diameter tube that matches the databases existing measurements within a margin...

Nice, I also use REW to measure. Where did you get your coupler from? I was thinking there should be a database of collected measurements for different drivers, similar to Crinacle's graph tool. I know there are a number of drivers for which you cannot find the actual frequency response curve...

I'm not doubting his abilities or knowledge, I've read many of his posts. But I'm sure he agrees, a scientific/engineering approach requires proper measurements. Measurements also help aid in better decision making and documentation of designs. That's just my perspective though. :ksc75smile:

Based on the posts I read, some people refer to certain builds with BS6 as close to "endgame" - guess I'll have to try to figure that out for myself. Yeah that is tough, attempting to engineer designs without being able to accurately measure them. Could you link to ones you think are adequate...

Thanks @Bassiklee I suppose what I'm curious about is what makes the Bellsing 6 so special? Could I just source any DTEC and 2 TWFK's and tune them together to accomplish the same result? If you don't have a coupler, how have you been measuring your builds to this point?

Isn't the Bellsing 6 (10013) just a DTEC with two TWFK clones?

I've left it on for long periods of time, don't really notice a difference either way. As Allan said, I dont think it really matters. Also for reference, the E90 + ESP-950 are my daily driver.

Same, waiting on Oppo to send me mailing address.

Just use an ad blocker and remove all the crap they've added.

The new site is a definite downgrade

Received the Canada unit today.   Impressed early on. Will use these a ton over the next week.

Didn't notice it til I read your post. Its almost imperceivable.

Thanks for sharing. Makes sense to use dynamics as mid range. Interesting that he matched the phase plot and used a high pass filter on the mid.

This is the perfect DAP. Just wish it had a USB DAC built in. That would make it the #1 DAP out there in my opinion.

Any updates?

I agree. There is something lacking, they do need feedback.   I wish I could have provided them with early feedback, have great ideas. Hopefully with their next player they collect this feedback. Their hardware is great.