{"id":68,"date":"2025-07-05T16:48:46","date_gmt":"2025-07-05T15:48:46","guid":{"rendered":"https:\/\/www.scratchart.nl\/?page_id=68"},"modified":"2025-07-06T13:05:07","modified_gmt":"2025-07-06T12:05:07","slug":"loudspeaker-projects","status":"publish","type":"page","link":"https:\/\/www.scratchart.nl\/index.php\/loudspeaker-projects\/","title":{"rendered":"Loudspeaker projects"},"content":{"rendered":"\t\t
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 If you are interested in more information, have a suggestion or need an amplifier printed circuit board, you are welcome to contact me (scratchart @ live.nl).<\/span><\/h1>\n
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2023 Mini loudspeaker all black<\/span><\/p>\n

The same as model 2020 except that new PCB’s are being used.<\/p>\n

No connectors exist on the back side anymore.<\/p>\n

The cables are directly fed into the standard.<\/p>\n

Also the stand is different.<\/p>\n

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Redesign 2023<\/span>. The speaker, designed together with my daughter in 2011 (see below),
had no woofer because it was designed for hearing impaired people.
The speaker was not in use, so either we had to throw it away or modify it to
something useful. On the flee market on Kings day I bought a simple set of Akai speakers
for nearly nothing and extracted the plastic woofers. The next step was to add a woofer
cabinet that also contains the active amplifier as built in 2020.
The result is amazing while very cheap drivers are being used!<\/p>\n

Frequency response measured at 3m in a living room:<\/p>\n

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Banana speakers 2022<\/span><\/p>\n

The speaker cabinet design is not mine. A running buddy of mine had the cabinets without speakers in his garage for 20 years. He had seen this design once and had it copied by a carpenter. It takes real craftsmanship to make this shape! Because the walls of the cabinet are never parallel, it will be difficult for resonance to occur in the cabinet. That’s a big advantage. He asked me to install speakers in it.<\/p>\n

Coincidentally, the broadband Tymphany ring radiator tweeter turned out to fit exactly in the existing tweeter hole. For the woofer I found the very nice Dayton RS225-4 8″ Reference Woofer, also fitting exactly. First of all, the inner walls were reinforced with partitions to reduce vibrations.<\/p>\n

The design of the electronics, including PCB, is mine. An active amplifier is built in. That is to say, a balanced input amplifier, an electronic 18 db\/oct crossover at 800 Hz, two separate power amplifiers, an active bass correction filter (the cabinet does not have a bass reflex port) so that the woofer goes straight down to 20 Hz and a circuit (\u201caudio switch\u201d) that automatically takes the amplifier out of standby when music is started. The power indication LED (green\/red, power\/standby) shines on the floor by chance and that gives an unexpected nice effect.<\/p>\n

The result is a uniquely shaped loudspeaker with high-end sound characteristics.
Amazing bass ! <\/p>\n

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Mini loudspeaker 2020<\/span>.
A small (30x12x12cm) but high quality loudspeaker with built-in amplifiers. So it can be connected to a media streamer directly without the need of a preamplifier.
It is completely constructed from laser-cut acrylate. It contains the Monacor SPH-100C 4″ woofer in a completely closed cabinet and the Tymphany XT25TG30-04 wideband ring radiator tweeter. Electronic crossover is at 750 Hz. The low frequencies are boosted with 12 db\/oct resulting in a very deep but bass, down to 30 Hz. <\/p>\n

Of course, they can not match the large array speakers. But the challenge here was to built a very small, good looking but still good loudspeaker.<\/p>\n

Frequency response measured at 3m in a living room:
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Model 2018<\/span>. A line array speaker with built-in amplifiers.
The challenge here was to make a system as good model 2017 but a little bit smaller
and much easier to build.
And very important, I wanted to use acrylate in order to make a modern design.
But the fabric cover of model 2017 is still a good option too.<\/p>\n

The listening room is an important factor for listening to music.
The music reaches your ears via reflections of the ceiling, floor and walls
to a large extend. An acoustic ceiling and carpets would help a lot but are often
difficult to realize. By using array loudspeakers, which bundle sound in a vertical way,
the effect of reflections from ceiling and floor is reduced.<\/p>\n

Dimensions: 120 x 26 x 11 cm<\/p>\n

Documentation can be found here<\/a><\/span>.<\/p>\n

 DFX drawings acrylic panels:<\/p>\n