Tau Passive 15

The best value for money PA speaker (considering market conditions in the summer of 2025). Total cost (summer 2025): 170 EUR.

15" passive full range speakers with similar performance start from 600 EUR.

It can be relatively easily accomplished with household tools in less than an hour.

Specs

• 70 cm height, 45 cm width, 39 cm depth
• 24 kg
• 2 db SpeakOn connectors in parallel (for daisy chaining)
• 35mm flange on bottom
• the thickest plastic housing we've ever seen, yet it has the look of a wooden speaker thanks to the classic textured black speaker paint
• relatively linear, modern sound -- sounds better than the average
• good SPL and distortion -- competes with the middle of the market

In a nutshell: remove the passive crossover and repurpose its speaker connectors to build a bi-amp system.

The videos are in Hungarian, sorry for that. We had a lot of fun messing around.

The speaker is used in bi-amp mode, therefore it can only be used with a properly configured DSP!

Limiter, maximum PEAK RMS power

300W for the midbass driver and 50W for the high. When using the same amplifier, the high gain should be set to -13 dB relative to the midbass.

Crossover Settings

Linkwitz-Riley, 48 db/oct for all bands.

• High: LR 48 highpass 2000 Hz
• Midbass: LR 48 lowpass 2000 Hz

Bass Protection

The speaker has surprisingly good bass performance, comfortably reaching down to 60 Hz without any additional equalization. Use the following settings to protect it:

• Standalone, full range use-case: LR 48 highpass 35Hz (crossover, Linkwitz-Riley)
• When used with subwoofers: LR 48 highpass 80Hz or above (crossover, Linkwitz-Riley)

Midbass Parametric EQ Settings

These adjustments improve linearity, remove boxy sound and unwanted resonances.

• PEQ 180 Hz, +2db, Q=4
• PEQ 330 Hz, -6db, Q=2
• PEQ 790 Hz, -2db, Q=10
• PEQ 1800 Hz, -6db, Q=10

High Parametric EQ Settings

These adjustments improve linearity and remove unwanted resonances. Don't forget to amplify the highs with -13 db less power.

• PEQ 14000 Hz, +12db, Q=0.44 --- if the highs are too strong, use +9db or +6db
• PEQ 5000 Hz, -8.5db, Q=10

• 1 pcs Pronomic C-215 MP 15" Passive Speaker. Also available in a stereo set (2 pcs)! If the link doesn't work, please visit Kirstein MusikHaus.
• Optional: 2 pcs speak-on panel connector (4 pole), if you don't want to reuse the ones in the passive crossover.

Tools

• PH2 bits/screwdrivers (not PZ!)
• soldering iron and solder
• optional: heat gun to remove the speak-on panel connector from the passive crossover