#2 Supercool analysts at GreyB (#IAMAGREYB)

Do you remember science classes in school where we used to DIY various projects?

You indeed do, it was one of the most innovative things we did as children, but as we grew up, this spark to DIY crazy tech dies and we get engrossed in our professional life. The only people I see innovating things are engineers, and that too is just for ‘Work.’ But for Tarun creating new and supercool things is beyond just ‘work’.

You might already know Tarun if you read our first part of Supercool Analysts at GreyB (#IAMGREYB)

For those who are new to this series. Let me introduce Tarun to you.

Tarun is a research analyst that has experience working in the Patent Search and Patent monetization team at GreyB, and he loves experimenting with new things. He loves to take random ideas from his imagination and bring them to life.

Don’t you love being surrounded by crazy, curious people? I sure do! And, GreyB is blooming with such talent, and our “DIY and Other Crazy tech” email thread is the proof.

The aim of starting this series is to bring the stories of such talented GreyBians to all the readers of our blog. This post is dedicated to Tarun – yet AGAIN!

Here is an email he shared last week and a look at the crazy tech he made at home.

SUB: DIY and other crazy tech

Hi folks,

It’s been a while. Initially, I had planned for a fancy video, but well, it’s hard enough to squeeze in time for the actual DIY.

So here’s my piece –

These are tower speakers standing about 4 feet tall, with most parts salvaged out of old speakers (right image – with the protective grille off).

Here’s what the initail CAD drawings looked like, not too far off !

Thanks to some CAD skills, a carpainter and a neat dual tone paint job, I managed to pull this one off in about a week’s time.

For this project, I chose a rare type of cabinet design – transmission line. These tend to sound ridiculously amazing and are extreemely expencive to buy. It comprises of an acoustic channel (like a really long pipe) that extends from the back of the speaker to the bass port. Unfortunately I don’t have any Iimages as the carpenter wasn’t kind enough to share them during the construction.

For the woofers I used old drivers salvaged out of a pair of Yamaha NS-35 bookshelf speakers (the ones in my previous mail). They are in excellent condition and sound like a dream.

For the tweeters, bought these. They’re very heavy and power hungry. Oh yes, extreemly fragile too, if you poke a finger into the tiny dome, it’s history !

For driving these I have a Marantz PM6006 amplifier. But one cannot simply connect these speakers in paralell and drive them through an amplifier. The signal from the amplifier has to go through a frequency divider (aka crossover circuit). It function is simple. The tweeter reproduces treble (or high frequency sounds – ~1800 Hz to 20,000 Hz). If one directly hooks it up with an amplifier, it’ll try to reproduce lower frequencies as well. In that attempt, it’ll sound horrible and then self descruct. For a woofer, splitting the frequencies results in better audio quality. Woofers won’t desctruct without it. Getting into the details of how it works is a whole subject. Here’s the crossover I used –

Before firing it up, the interior walls have to be damped with a copious amount of sound absorbing material. Absence of this damping material will result in standing waves between opposing walls of the cabinet and the whole thing will sound horribly wrong.

I had used cotton wool for this purpose.

Last but not the least. The whole thing has got to look pretty. Else, it’ll have to stay out. So, I had it spray painted in dual tone to match the shades in my room. It very important for something so big to blend well with the colours of the room.

It was a lot of fun working on this late at night with a friend and loud music

Designing a loudspeaker is a complex and iterative process. To keep this mail brief, I’ve left out most of the details. If you need more information, I’ll be happy to share the CAD files or any other details.

Cheers,

Tarun