maybe there a more comments following about the physical design of the speakers


In the beginning we came up with the following constraints/ideas:

  • Subwoofer & Tweeter (2-way design)
  • 30l volume
  • design the crossover ourselves

Due to discount at VisaTon we ordered the speakers there. Based on recommendations from our supervisor at the university we chose:

Measuring the frequency response

We started with measuring the frequency response of the tweeter and subwoofer. Thanks to the institute we had the perfect equipment.

Anechoic Chamber

Frequency Response Tweeter

Frequency Response Subwoofer

Unfortunately there was no better way to export the graphs. The software was running in virtual machine due to incompatibility/dependencie problems.

Anybody got some good opensource alternatives?

Designing the crossover

The software Bassyst was used. There we designed the highpass and lowpass filter. We got a lot of valuable comments from our supervisors and came up with the following design after looking up the available components and taking the price into consideration.

Highpass Filter

Lowpass Filter

The red curve displays the optimal/target frequency response while the blue curve is the real frequency response using the gathered data from the speaker measurements and running the signal through our designed crossover.

Frequency Response

After designing the crossover and receiving the components. We set up a draft and did some measurements.
We were more than happy with the results.

First Draft Assembly for Test Measurement

Since the crossover worked, we designed a PCB with the size of the components in mind. The PCB was later etched.

PCB Crossover

Components Layout

This is the final crossover assembled on the PCB and bolted into the speaker.

Assembled Crossover Inside the Speaker

Finished with Amplifier SMSL AD18

I like them, they sound good.

Building your own stereo speakers & audio crossover