Description
This system doesn't actually belong to me . . . but I designed and built it in its current form for the owner, so I figured it would be appropriate for me to post it here.
I feel that the origins of true 'high-end' audio are in systems like this one - built in the mid-20th-century as comissions from wealthy music lovers, who themselves don't really care too much about equipment. This system was originally purchased by a midwestern dentist who was an avid classical music enthusiast, and simply wanted the best possible sound in his home. So in about 1954, he put his faith in his local custom stereo dealer, and had a top-notch monaural system custom-installed in his modest 900 sq. ft. suburban house. Speakers were all JBL -- 4 15" D130 woofers, and a big slant-plate 537-512 horn with 375 driver. Preamp and Amp were Marantz (models 1 & 2), with a Scott turntable, Grey tonearm, and Fairchild cartridge. He was thrilled.
About two years later, "stereo" was the new thing that he had to have. So of course, he bought a duplicate set of the JBL speakers and Marantz preamp and amp - with an Ampex 121 tape recorder . . . and all of this was again custom installed into the walls of his home. In 1960 he added 2 JBL 075 super-tweeters, and this would be the driver complement for the next 47 years.
In 1961, the dentist was becoming increasingly confined to a wheelchair due to the affliction of Multiple Sclerosis, and was spending most of his time at home with his music collection and his hi-fi system. He decided to build a new house with two goals in mind -- first, to have everything accessable from a wheelchair . . . but also (probably more importantly), to build a dedicated listening room.
This installation is what is shown in my "before" pictures. The loudspeakers were installed in an infinate-baffle arrangement, using the two-car garage (!) as an enclosure. The demising wall (used as a speaker baffle) is 3/4" plywood screwed and glued to the studs, and then filled with a couple thousand pounds of sand. A very thin grillecloth placed over the front of the speakers is flush with the room's wood paneling and matches it perfectly - making the whole system completely invisible. The power amps were mounted in the unfinished basement below, and all of the source equipment was hidden in a cabinet at the opposite end of the room, at wheelchair height. At this time, the Scott turntable was replaced with a Thorens TD124/SME 3009 with an Ortofon cartridge.
The dentist enjoyed this system until his death - I'm guessing sometime in the early-to-mid 1980s. His widow didn't use it at all, so it sat dormant until she died in the early-1990s. Fortunately for the classic hi-fi, an attorney was looking for a new home, and looked at several . . . in his words: "I didn't like any of them. But this house had the stereo, and that's what mattered." The attorney had a passion for jazz very much like the dentist's passion for classical - and upon moving in, turned on the system. It crackled and popped, but came back to life and started to play music again. The attorney connected his existing CD player and cassette deck and used it.
It was around this time that I first became involved, as the main high-end audio servicer in town. The original pair of Marantz mono preamps had been replaced with a McIntosh C26, but everything else was unchanged from when it was installed. I rebuilt the Marantz power amps and the Thorens TD124, and installed a Shure V15-V. A shot of cleaner on the crossover L-Pads was all that was required for the speaker system.
The dentist's old system continued this way for many more years, running on average about 5-10 hours a day. Except for a few new sets of EL-34s and an occasional scratchy control, no service was required. I left the business of servicing high-end audio, but would still perform maintainance on this system, mainly just to make sure it was preserved. And then in early 2007, the attorney informed me that his house was simply getting way too small for his family (and his CD/record collection), and they would have to move. And he wanted to take the stereo with him . . . and since it had made one move already, I thought, why not? But in the tradition of the dentist, we'd have to improve it a bit in the process, without ruining its essential character.
Conceptually, it would still be a built-in system, integrated with custom cabinetry around it - fortunately, I had the talents of a master cabinetmaker at my disposal. But there was no chance that a garage or attic could be used for an infinate-baffle arrangement, so I had to design enclosures to get as good (or better) bass response from a much smaller volume, and still use the same drivers! The other issue was that the 537-512 slant-plate horn is huge, and requires considerable clearance behind it - which was simply not available at the new home.
My solution was to turn a three-way system into a four-way. All of the drivers were rebuilt with new cones/diaphragms, as they had deteriorated a bit in their 50-year-plus lifetime. So two of the 15" D130s (per side) were rebuilt with original-style cones, which were put in a sealed box to handle the mid-bass - these would preserve the midrange quality of the old system. The remaining two were rebuilt with 2235 cones (heavier with much lower Fs of 20Hz), mounted in a reflex cabinet to handle the low bass, and make an improvement over the old system. The rebuilt 375 midrange drivers were mounted to new 2382 constant-directivity horns (solving the depth/size issue), and the 075 tweeters were changed to 077s, which have a wider coverage angle that's a better match to the 2382.
I designed and built new fourth-order passive crossovers for the mid-bass, midrange, and tweeters - these are all run from the original Marantz amplifiers. A new McIntosh MC275 MkV was added for the bass, with an Ashly electronic crossover. The speaker cabinets were built as separately from the surrounding cabinetry, and have a 1/4" gap around all sides for vibration isolation. The turntable platform extends through the back of the cabinet and is anchored to the wall to isolate it from both the speakers and the cabinetry.
So what does it sound like? Not suprisingly, the sound is very much like a pair of big JBL studio monitors - they have the timbre and punch of a pair of 4350s, but the midrange and high end has the smoothness of something like the 4435s (big butt-cheeks). Big, effortless dynamics, and it plays WAY loud, but I enjoy their presentation of solo classical piano as well. The dentist would have been proud.
Finally, I'll put in a shameless plug for my cabinetmaker, who for the most part, made it all possible:
[url]http://www.roundtreedesign.com[/url]
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