Originally Posted by ChrisBee
Critics are two a penny these days.That's a priceless luxury you earned off our early experiments and efforts at our own expense. If you don't like an idea then just ignore it or do a proper anlaysis. Or throw one together just to prove how awful it is. Then you've earned the right to trash an idea which you clearly don't even understand at the most basic level. You had the drawing but you still needed single syllable decriptions to grasp the concept?
I don't need to build to prove anything. My Tricolumn days were back in the late 60s when every single Watt and Hz of extension was precious. Subwoofers in 1968/9 were as rare as hen's teeth. No longthrow Chinese drivers at pocket money prices either. No sonotubes. No free software test facilities or cheap SPL meters. (thankyou Sir JohnM) No Behringer EP2500 1kW amps for less than a week's wages for a factory worker. No routers or other affordable electric tools to produce a sub in a weekend. No internet to share potential ideas freely with your audio friends right across the globe without expectation of payment or reward or sympathy. (just simple respect) There was no easily affordable SVS Ultra to fall back on as your reference for what is acceptable or probably inadequate.
My big Tricolumn sub was made out of a stack of big, empty, steel drums. Which all had to have the tops and bottoms cut out with a hammer and wood chisel on the kitchen floor of our flat/apartment. (with the door shut!) Then all taped together to make a big tube. The speaker cutout was made with a keyhole saw handle with a stub of hacksaw blade jutting out. Smaller holes were made with a hand drill and blunt, carbon steel drills. (Which quickly burnt out in the single high speed B&D electric drills of those days) The speaker cable was twin clear lighting flex from the 10 watt Mullard 510 mono, valve, power amp. The driver was a 10" Whitely cambric reinforced paper cone and corrugated surround. Xmax was probably a millimeter or two but I hadn't heard of TS parameters in my borrowed reference (library) books or "Wireless World" back then.
There wasn't much snake oil to discolour your wads of spare pound notes or dollar bills back in the "Good Old Days". Just enthusiasm, inspiration, aching arms, blistered fingers and sticking plasters. When you can claim to have carried 112lbs of damp sand (for a reflex corner baffle experiment) 13 miles home from the nearest wharf on a bicycle...then baked every precious spoonful on your wife's cooker to dry it out before use ... then you're an audio enthusiast and have probably paid your dues. You don't need to prove anything to anybody. Least of all to a forum "expert" with (apparently) no manners and a remarkably poor grasp of potential enclosure designs.
Have a nice day.
Interesting story. It brought back many memories and one I thought I should relate:
33 years ago, I got the idea to build 3-way speakers that had a separate woofer box, in which was contained the crossover and a 12" woofer in a ported box of 3 cubes, a separate 6" midrange cube and another separate (and pretty cool looking, slim box, if I say so myself) with 2 tweeters.
The mid and tweet boxes wired off the back terminals of the woofer box from the crossover and could be placed for maximum sound stage in any room.
I used sink cutouts from our counter top shop to build the woofer box, which already had laminate on one side, which I turned to the inside of the box. I then laminated the boxes with wood grain laminate.
Although I co-owned a kitchen/bath company and had access to table saws, routers and saber saws, I used fairly rudimentary tools and built them at home in my spare time. I based the design on ideas gathered and sifted from the book 'Hi Fi Loudspeakers and Enclosures' published in 1947 (IIRC). It had all of the theory for horns, ported, drone-cone inverters, folded horns, sealed, infinite baffle, etc., and had designs from Bozak, Klipsch, Jensen, Altec, Lansing (JBL was signed Jimmy B Lansing on the back of the box of one of them), University, Wharfdale, etc.
I built a couple dozen sets and sold them back in 1975-76, allowing the purchasers to select their own wood grain. I fondly remember my wife and I, newly married, in a tiny apartment with saw dust up to our ankles in the living room from me routing the laminate trim, while she soldered all of the connections.
I recently was contacted by one of the purchasers who told me that his basement was recently flooded in a storm and his speakers were destroyed. He asked if I would build him another set like he had. I explained that technology has made leaps forward and that it would be more economical and offer more design choices to just buy a pair from any number of manufacturers.
He asked if I would draw plans for the speakers so that he might try to build a set himself because he wanted those speakers in that design. He used them in his shop and placed the woofers in niches and had built shelves for the mids and tweeters so that the sound was good anywhere in his shop (according to him).
Well, I decided to rummage through my attic and sure enough, I found an old set that I had used myself and saved (I save EVERYTHING).
I decided to blow off the dust and ship them to this guy so that they'd have a home and he'd be happy to get what he wanted, free of charge.
In the process, I noticed and remembered the hand wound coils in the crossovers that we made ourselves with a drill, spool and wire, as well as the clever little things I would write inside the boxes for posterity
I calculated the box size and port with a slide rule because I couldn't afford the exorbitant price of a calculator when they first came available, etc.
We hooked them up and measured them. Since the components are separate, they were easy enough to measure separately and then as a whole.
I must say how stunned I was to see the accuracy of the overall FR as well as the slopes and points of the crossover. The ported box was flat to 28Hz and they had a slightly rising response from 10K to 20K. In fact, I am amazed that the rubber surround (a rarity 35 years ago vs cheap foam or corrugated, impregnated accordion-type surrounds) of the woofers was still intact and that everything was in near-perfect working order.
The speakers were delivered last Saturday to a very grateful guy who will have them until the next natural cause of their demise, which is pretty cool to me.
I bought the drivers from a high school friend who was a stateside distributor for Phillips. He went on to have many amazing experiences in pro sound, including a long meeting with Paul Klipsch who explained to him that those old timers had discovered, discussed and written about things like digital, fiber optics and solid state in the late 40s, and then proceeded to prove it by pulling articles from his vast library, which was adjacent to his office.
Sorry for the ramblings, and apologies to the youngsters who are somehow put off by these sorts of stories, but I wanted you to know that I always enjoy the old war stories like yours. I appreciate your input, even though I'm not up on horns and other larger solutions like PK, et al.