Need advice.... BSC on 1.5,inch drivers? Any poin?t?

[3rutu5]

Been fiddling around with the print for the tiny ghetto blaster and was wondering if there would be any point/need etc to have a BSC or any other filter on these tiny drivers? I'm using the DMA45-08's for this project

[neildavis]

This would be a good application for one of those new 4-channel BT/DSP boards. You could add a tweeter and have a nice 2-way stereo BT setup. I've been working on the CPU code for an ESP32 micro that lets you control this amp using your cell phone. One of the menu items is BSC, which for this design would be fairly high (800Hz and up). It's also got full EQ and ADI's SuperBass algorithm. I still need to add the ADI DynamicBass algorithm, which will adjust the bass HPF based on the volume. Once I finish that, I will post a link to the code at this location: Mom’s Bluetooth Garden Table – Audiodevelopers Reborn. The link currently only has some background info, but details are coming...

I like the work you are doing with 3D printing, and I see a good match with the electronics described on my website. I'd be happy to send you a CPU or working CPU/amp, if postage isn't too nuts.

[Billet]

Think of baffle step as a tone control, add it if needed.

[DeZZar]

Baffle step happens regardless of the size of the driver. Where it occurs is a relationship between driver size and baffle size. Use the Diffraction tool in Vituix to play around with different baffle sizes, drivers sizes and driver positions to see the effects.

[DeZZar]

1.8 - 2.0mh + 8ohm.

[3rutu5]

So being only 2 1.5 drivers, this isn't going to act as a low pass but instead remove any humps around 300?

[3rutu5]

Damn was going through my left overs, had 2 DNR-4's, 2 LW18-50's, 2 2.5 iron cores and some other things.

[3rutu5]

This would be a good application for one of those new 4-channel BT/DSP boards. You could add a tweeter and have a nice 2-way stereo BT setup. I've been working on the CPU code for an ESP32 micro that lets you control this amp using your cell phone. One of the menu items is BSC, which for this design would be fairly high (800Hz and up). It's also got full EQ and ADI's SuperBass algorithm. I still need to add the ADI DynamicBass algorithm, which will adjust the bass HPF based on the volume. Once I finish that, I will post a link to the code at this location: Mom’s Bluetooth Garden Table – Audiodevelopers Reborn. The link currently only has some background info, but details are coming...

I like the work you are doing with 3D printing, and I see a good match with the electronics described on my website. I'd be happy to send you a CPU or working CPU/amp, if postage isn't too nuts.

Hey mate, I don't think I have much room internally on this one as it is a quick reduction of the bigger one I'm hoping to do. I'll have a look later tonight after work, oh and I'm an Australian so probably cost a kidney to send anything my way

[DeZZar]

So being only 2 1.5 drivers, this isn't going to act as a low pass but instead remove any humps around 300?

No its a shelf filter. It does this:



Which is the opposite of the baffle step effect which in something like this:




On its own it wont compensate for anything else going on with the driver.

[3rutu5]

Sorry if I add if on its own it won't compensate?

[DeZZar]

No it will compensate for baffle step, I meant it won't compensate for anything else. It might need a notch or something also depending on the response of these drivers.

[3rutu5]

Too easy, thanks mate. I grabbed some jantzen inductors and some 8.2ohm res from a local joint. Hopefully come by the weekend

[Chris Roemer]

The BSC filter CAN be used (externally) on any (impedance compatible - to the filter "load") speaker - between the speaker and the amp.
(Like if you had a small pr. of computer speakers (w/OUT BSC) and just wanted to temp. "try" the filter to see if you liked it.)

I know YOU won't be using it in this way, since everything'll be inside your B-Box. Just sayin'.

[fpitas]

The (tiny) elephant in the room here is your drivers will run out of Xmax even quicker.

[3rutu5]

yeah that is true and most on here know i try to break the speakers first run....its going to be interesting on what im wanting to do thats for sure

[3rutu5]

No its a shelf filter. It does this:



Which is the opposite of the baffle step effect which in something like this:




On its own it wont compensate for anything else going on with the driver.

Hey mate, me again, you mentioned series for this filter, so dumb question I assume that means soldering from the wire to the inductor, then inductor to the resistor then to the other end of the wire

--------|----R------->+

I finally got aeound to fixing my printer so reprinting the tiny Bluetooth speaker idea

[JRT]

No. The filter is comprised of inductor and resistor wired in parallel. The filter is wired in series with the speaker. The effect is that the resistor is in series with the load current and the inductor provides a bypass path for current around the resistor at lower frequencies.

[3rutu5]

Thanks just noticed it, it was the 18 Guage series not the thing in series.....what a. Doofus, put that down to being half asleep

[DeZZar]

Looks like you're all sorted. Don't worry I still end up questioning myself - is this series or parallel? But yeah as JRT pointed out, parts in parallel, filter in series with driver. The inductor controls the point where the attenuation starts and the resistor controls how much attenuation is applied.