Gradiente Mini-Oito speakers from 1971 - Restoration, history, analysis and tests

Links to parts of the video
- Presentation 0:00
- Historical context and why there are two generations of the Mini-Oito 1:25
- Difficulties encountered in the restoration 13:21
- Why did Gradiente choose the Passive Radiator system? 20:20
- How the boxes got to us 28:47
- How were the original speakers 30:29
- Restored Woofers Test 34:06
- Measuring the resonance frequency with... RICE ??? 36:41
- Checking passive radiator tuning 40:52
- Internal connections and 42:46 frequency divider
- How the carpentry looked after the restoration 45:40
- Final assembly of components 47:51
- How the boxes looked after they were ready 56:54
- How the tests were carried out 57:45
- Frequency response with white noise 59:01
- Test with song #1 - KZbin Instrumental 1:01:18
- Test with song #2 - Song with vocals 1:02:47
- Final considerations 1:04:17
Manufactured in 1971 with special Novik speakers, these Mini-Oito speakers had an amazing sound for the time. But do they still meet current needs?
What are the difficulties in restoring yourself? Will it be good? These and other points are discussed in this video, where we show step-by-step how the restoration took place and explain the history of this model to understand why it was made this way and not another.
Gradiente was one of the first companies to design and manufacture transistor amplifiers in Brazil. They needed compatible speakers and so the company's first line was created, with several models including the Mini-Oito shown in this video.
We had a lot of difficulties restoring this box, but in the end we managed to make it very similar to the originals and we were able to evaluate what they sound like, what purpose they serve and we carried out several tests that are shown in the video.