rajeshsundaram
New Member
- Joined
- Apr 30, 2008
- Messages
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This is the story of an experiment gone right!
It all started when a fellow BHPian posted a pair of 4" Ultimate speakers for sale in the Classifieds section. I jumped in, PMed him, transferred money and received a pack-sealed, un-used lovely 4" ULTIMATE - T1s (Ultimate models packs a punch! but because of their understated looks they dont stand in the show biz unfortunately). Only then I realized I had no idea on what to do with the speakers!
Meeting the Carpenter:
Fast forward few months, one day, I happened to locate a carpenter in the next street and immediately an idea was born. Decided to check if the carpenter can build speaker enclosures. Spoke to him and he asked me to show me the design model. He had not worked on any speaker enclosure for a long time. Had my doubts about his workmanship quality. But decided to give a try.
Selecting an Enclosure design:
Rushed home, browsed my computer archives and found the speaker enclosure design PDFs from FOSTEX. Fostex is a japanese brand specializing in full-range drivers as well as mid-bass and tweeter drivers. They are one of the few manufacturers who put up speaker enclosure designs for free in their website. I had downloaded their whole bunch and archived it some 4 years ago. Now, having located them I skimmed through and found a matching double-bass reflex enclosure which seemed to be a perfect for the 4" Ultimate T-1s.
Last I read, Fostex products are available from Coimbatore based AUDIRE technologies who specializes in their own portfolio of speakers and amps.
3D Design:
Kick started Google Sketchup and sketched a 3D design matching the dimensions of the enclosure in PDF. Instead of the 73mm hole for the speaker, I opted for a 100mm hole matching the T1s. I know, the sound character will change. But i am okay with that.
Construction:
Met the carpenter again, explained the design (took a lot of time to convince him to start the work) and handed him the print-outs and the speakers. The construction took nearly a whole day (I was in the office, so no photos could be taken). As mentioned in the Fostex PDF, 15mm plywood was used. The carpenter did a okay job. He was not keen on doing such precision jobs. His interests lies only in easier, money-making jobs. So the construction was little crude, with not-so-precise position of the ports and some visible gaps inside the inner-port plank. Brought the boxes to home and this is how they looked.
The Amplifier
Now the speakers are almost ready in draft fit. Next item to procure is an amplifier. With the least budget in hand, I cannot afford any high-end stereo amps. So I called my friend in Karur who assembles Audio amplifiers. After a brief explanation of my idea, he suggested to settle for a 50w+50w stereo amp which will be more than enough for my requirements. Then came the important question. MOSFET or STK ? We squared on MOSFET based design. He informed me that there is a temporary shortage of MOSFET supply in his town and asked me if I can get the mosfets from Chennai. As I was busy with office works at that time, I decided to settle for STK which was available in his town. He agreed and sourced a STK 4192 II, a 50+50w IC. Soon things started building up, and the amp was ready in a compact body. He slotted an additional USB card reader (some chinese make) just for my convenience. Received the amp after a week of random testing.
contd ...
It all started when a fellow BHPian posted a pair of 4" Ultimate speakers for sale in the Classifieds section. I jumped in, PMed him, transferred money and received a pack-sealed, un-used lovely 4" ULTIMATE - T1s (Ultimate models packs a punch! but because of their understated looks they dont stand in the show biz unfortunately). Only then I realized I had no idea on what to do with the speakers!
Meeting the Carpenter:
Fast forward few months, one day, I happened to locate a carpenter in the next street and immediately an idea was born. Decided to check if the carpenter can build speaker enclosures. Spoke to him and he asked me to show me the design model. He had not worked on any speaker enclosure for a long time. Had my doubts about his workmanship quality. But decided to give a try.
Selecting an Enclosure design:
Rushed home, browsed my computer archives and found the speaker enclosure design PDFs from FOSTEX. Fostex is a japanese brand specializing in full-range drivers as well as mid-bass and tweeter drivers. They are one of the few manufacturers who put up speaker enclosure designs for free in their website. I had downloaded their whole bunch and archived it some 4 years ago. Now, having located them I skimmed through and found a matching double-bass reflex enclosure which seemed to be a perfect for the 4" Ultimate T-1s.
Last I read, Fostex products are available from Coimbatore based AUDIRE technologies who specializes in their own portfolio of speakers and amps.
3D Design:
Kick started Google Sketchup and sketched a 3D design matching the dimensions of the enclosure in PDF. Instead of the 73mm hole for the speaker, I opted for a 100mm hole matching the T1s. I know, the sound character will change. But i am okay with that.
Construction:
Met the carpenter again, explained the design (took a lot of time to convince him to start the work) and handed him the print-outs and the speakers. The construction took nearly a whole day (I was in the office, so no photos could be taken). As mentioned in the Fostex PDF, 15mm plywood was used. The carpenter did a okay job. He was not keen on doing such precision jobs. His interests lies only in easier, money-making jobs. So the construction was little crude, with not-so-precise position of the ports and some visible gaps inside the inner-port plank. Brought the boxes to home and this is how they looked.
The Amplifier
Now the speakers are almost ready in draft fit. Next item to procure is an amplifier. With the least budget in hand, I cannot afford any high-end stereo amps. So I called my friend in Karur who assembles Audio amplifiers. After a brief explanation of my idea, he suggested to settle for a 50w+50w stereo amp which will be more than enough for my requirements. Then came the important question. MOSFET or STK ? We squared on MOSFET based design. He informed me that there is a temporary shortage of MOSFET supply in his town and asked me if I can get the mosfets from Chennai. As I was busy with office works at that time, I decided to settle for STK which was available in his town. He agreed and sourced a STK 4192 II, a 50+50w IC. Soon things started building up, and the amp was ready in a compact body. He slotted an additional USB card reader (some chinese make) just for my convenience. Received the amp after a week of random testing.
contd ...
