Small 2-way speakers with linear on-axis and power response characteristics (Scan Speak and SB Acoustics drivers). H&V off-axis measurements included

[prxprx]

Thanks for your reply XMechanik! Yeah, I think the distortion figures of the Mechano23 are more than good enough for me.
The size and price advantage of the Mechano23 are reasons why I'm currently leaning towards that design.

But, charts and specs are only half the story ofcourse. Which design would sound better? That's very subjective, I know. But I also like a nice wide soundstage and good imaging.

 

[Roland68]

@XMechanik and everyone else, do you want to laugh?
I just searched for Mechano323 on google and then got this link, which apparently leads to an AI generated page that was generated for my query.

https://brainrusher.com/where-to-buy-mechano323/

 

[Gringoaudio1]

Nice template. The site that Mechano323 looks to be a template for building a page. Not just dumb ai generated nonsense.

 

[XMechanik]

Which design would sound better? That's very subjective, I know.

Judging my preferences based on playing time, it would be Mechano23. But that's probably because there's a certain "small speakers - big sound" effect here, which I seem to appreciate.

 

[XMechanik]

@XMechanik and everyone else, do you want to laugh?
I just searched for Mechano323 on google and then got this link, which apparently leads to an AI generated page that was generated for my query.

https://brainrusher.com/where-to-buy-mechano323/

8 chapters, 0 information. Another example that artificial intelligence is often nothing more but artificial nonsense .

 

[prxprx]

Judging my preferences based on playing time, it would be Mechano23. But that's probably because there's a certain "small speakers - big sound" effect here, which I seem to appreciate.

Love it, I have the same appreciation for small speakers. I'll probably end up making stands that include a small subwoofer anyway. But that's something for later.

 

[wineds]

Prototype xover PCBs arrived today. Just finished assembling one. So far so good. Need to get it hooked up to drivers next to test.

 

[XMechanik]

Looks neat and pro.

 

[mumpgod]

or

You may also attach photos of your connections when you're done, if something goes wrong it will be easy to spot and give feedback.


Take care!

Okay, finally got all my parts in. Would appreciate it if anyone could verify my crossover wiring. Arrows just indicate left or right wire of each component .

Thanks in advance!

 

[Raxumit]

Prototype xover PCBs arrived today. Just finished assembling one. So far so good. Need to get it hooked up to drivers next to test.

It will be useful either way, but does it fit through the woofer hole on the baffle?

 

[wineds]

It will be useful either way, but does it fit through the woofer hole on the baffle?

I don't have cabinets yet but I 3d printed a ring with 127mm ID and xover easily goes through it. PCB is 112 mm* 134.8 mm

 

[wineds]

I used LIMP to measure free air impedance. This is what I got: Does this look about right?

 

[Inertiaman]

Prototype xover PCBs arrived today. Just finished assembling one. So far so good. Need to get it hooked up to drivers next to test.

Isn't the coil orientation potentially problematic? The larger two coils at the left/top of your photo, in particular, seem to match example #5 here

Or am I (or the originator of the linked graphic) overthinking it?

 

[wineds]

Isn't the coil orientation potentially problematic? The larger two coils at the left/top of your photo, in particular, seem to match example #5 here

Or am I (or the originator of the linked graphic) overthinking it?

I don't think it's quite like example 5. In that example the axis of two coils intersect which is not the case with my PCB.

 

[Inertiaman]

I don't think it's quite like example 5. In that example the axis of two coils intersect which is not the case with my PCB.

Its exactly like example 5. The magnetic field lines of your coils (axis at center of your coils) intersect. Or perhaps offset only by the slight difference in coil radius.

EDIT: its arguably case #4, since the center to center distance of your coils is < 10cm (my visual guess is ~ 5cm)

 

[Inertiaman]

Not trying to be critical or pick a fight, and I appreciate the contribution to the group of your PCB work. Really just making observations and wondering if this is a concern (or not).
If this x-over PCB may be re-used by others, I think its worth consideration?

My observation on your layout:
L1 axis intersects with L2 and L4
L2 axis intersects with L1 and L3
L3 axis intersects with L2 and L4
L4 intersects with L3 and L1
this based on XMechanik's original schematic definition of L1/2/3/4 as placed in your photo with upper right coil is L1, lower right is L2, lower left is L3 and upper left is L4
some of these "intersections" are offset slightly due to difference in coil radius, but the "field lines" (in fuzzy sense) definitely intersect

FWIW, @mumpgod's layout (post #269) also has some field line intersections (between L1:L4 and L2:L3) but fewer of them, because he has laid some coils flat and some on edge, rather than all on edge. (conveniently, his photo has the coils in the same relative corner positions as yours, so easy to compare).

Contrast this with the photos of original crossovers by XMechanik in post #1. Only L1 (.33mH) and L3 (1.5mH) coils have intersecting field lines, and they seem to be significantly further distant from each other since they are diagonally opposite.

I don't have the experience to offer an informed opinion that this will (or will not) meaningfully impact the crossover performance. I just noticed that it deviated from my perception of "best practice". I'm hoping others might chime in on practical consequences.

 

[wineds]

Yes it's worthy of consideration. Thanks. The PCB is a prototype and I won't release the Gerber files to the public domain until it has been resolved that it performs as intended. Please bear in mind also the constraint that the board needs to fit through the woofer hole. And within reason is as small as possible to keep costs down.

 

[Inertiaman]

Yes it's worthy of consideration. Thanks. The PCB is a prototype and I won't release the Gerber files to the public domain until it has been resolved that it performs as intended. Please bear in mind also the constraint that the board needs to fit through the woofer hole. And within reason is as small as possible to keep costs down.

Yep, a speaker design is nothing if not a series of trade-offs and compromises!

 

[wineds]

Okay, finally got all my parts in. Would appreciate it if anyone could verify my crossover wiring. Arrows just indicate left or right wire of each component .

Thanks in advance!

View attachment 392145

I'm struggling to visualize whether it is wired correctly sorry but just in case you don't know the enamel needs to be scrapped/sanded off the ends of the inductor wires before soldering. You can use something like an exacto knife and/or sandpaper.

 

[ajax247]

>> You can use something like an exacto knife and/or sandpaper.

I find a cabinet scraper works nicely for removing that enamel.

Just finished a pair using a passive radiator mounted on the side of each speaker box, following Chris*42's approach (https://www.audiosciencereview.com/...-open-source-diy-speaker-review.54066/page-12). The huge radiator hole makes installing the crossover boards a bit easier. Impressive sound!