Here, videos are collected that were created during various practical works. They are intended to clarify the technical background. Use in YouTube ⚙ Subtitles for videos in German language.

Exchange of a HiVi F12 woofer against Scan-Speak 32W/8878T01

A HiVi F12 woofer is to be exchanged for a Scan-Speak 32W/8878T01. Here, the overall concept (Lamm 1.2 Reference power amplifier, Expolinear Görlich midrange and Magnat MP02 plasma tweeter) is presented and the measurement is planned.

Frequency response and impulse response of the old speaker are measured. A Samsung tablet with Android 9 via USB 3.1 (USB C used as USB OTG) with a Shure X2U XLR-USB adapter (or microphone amplifier) is used. The tablet runs Hifi Apps Speaker Setup.

The Thiele-Small parameters f_0 and Q_ts are explained clearly with the help of a model, the resonant frequency of a Scan Speak woofer 32W/8878T01 is measured for demonstration "old school" with function generator and oscilloscope.

The new Scan Speak 32W/8878T01 are now installed and measured through. To understand the frequency response, it is compared with that of the previously installed bass speakers, a near-field measurement and the manufacturer's data. Certain fluctuations can be clearly assigned to floor reflections. Near field measurements are used to measure the resonances of the bass reflex cabinet and the loudspeaker and it is shown that the frequency response interacts very well with the characteristics of the room. The use of electronic filters (equalizer, FIR) and the limitations of the technology are explained.