Jump to content
The Classic Speaker Pages Discussion Forums


  • Content count

  • Joined

  • Last visited

Community Reputation

0 Neutral

About rnathans00

  • Rank

Profile Information

  • Gender
  1. rnathans00

    WTB - Allison CD-7 Speakers

    I feel funny leaving such a post, as I already have a modified set that's drawn only modest interest. But I have a special project in mind that can utilize a box of just such a size with a woofer opening on top. Better condition and working components obviously enhances its value, but reasonable proximity to DC is essential. I found such a set listed in the NYC area, but it's a six-hour drive away, so that won't work. I'd just rather not tear my working set apart just for a project, but parting out my Allisons - woofers, top/front grills, SB Acoustic tweeters - is an ultimate option.
  2. rnathans00


    Itch, you might want to check with the KAB site, kabusa.com. They offer a lot of custom parts for the SL 1200 series.
  3. I finally have a lead on a set of Allison Three speakers - the original version, not unfortunately the much later Kentucky upgrade. Aside from needing the woofers repaired, I'd be interested in upgrading the terminal pins , which only handle thin wires, and possibly upgrading the caps. While I'm normally an "if it ain't broke don't fix it" kinda' guy, an experience with my CD-6 set suggested a simple upgrade could be worthwhile. (One had a bad cap, I upgraded with a modestly priced Erse, and all was well. I ended up doing the same upgrade on the second speaker.) But how does one get to the Allison Three's crossover? There's no obvious way to get to it from the outside, as I could on the CD-6. My understanding is it's on a board that's stuck against the back panel, but how does one get to it? I'd hesitate to remove the midrange and tweeter, given those fine wires they're attached to, which leaves the woofer way at the bottom, which is well out of reach of the back panel. So how is it done? Thanks in advance for any insights.
  4. Looking for a nice pair of Outlaw LCR speakers (actually manufactured by Snell) or Snell LCR7s, preferably in the Cherry finish. I had to pass on the last set of Snells I saw listed, because it involved FIVE shipped from the west coast, which would have been rather pricey. A pair of those Outlaws recently appeared, but they were more than I was willing to pay for black. Neither of these speakers show up very frequently. I sometimes wonder if they didn't sell very well, or if they're so good people simply don't part with them. This buyer is in Washington, DC.
  5. rnathans00

    Allison Sevens

    I have a set of CD-7s in walnut here in Washington, DC that have yet to find a buyer, maybe because they're modified from the original. A speaker designer checking out one with a faulty tweeter convinced me to install more "modern" tweeters in the two - SB Acoustics - and he designed a far more complex crossover for them. I've been using them as surrounds, which is a waste I think, and the CD-6s - all original except I replaced the caps - serve as fronts simply because of the room layout. (The CD-6 will fit atop a convector module; the CD-7 obviously won't.) If you're near enough I might grab them just to get those nice oak cabinets (matching my CD-6) and have a few parts as spares. (My grills and drivers are all intact.)
  6. Need a nice set of stand-mounts for a secondary system. The Revel M20 and Snell LCR7 are first choices. Looking only for the wood finishes - cherry, sycamore, etc. Thanks.
  7. Offered for sale in Washington, DC are the well-regarded Allison CD-7 Minitowers. In the middle of the CD line, the 7 is a floor-stander (27-1/2”H x 9-5/8”W x 9-5/8”D), so no stands are required. Allisons are designed to provide a large sound-field, so there’s no limited “sweet spot”. These however have been modified and upgraded from the originals. Some time back I noticed in problem in one speaker which was traced to its tweeter, which was working but had wildly uneven frequency response. Since it’s hard to know what the true quality of a “working” Allison tweeter found, say, on eBay, is, I worked with a local speaker designer to remake my CD-7s with new tweeters and a modern crossover. The original tweeters were replaced with SB Acoustics SB29RDC tweeters. And in place of the original, simple (coil and two capacitors) crossover, a much more sophisticated crossover was designed . The parts to the crossover alone cost over $50. The woofers are Allison originals, and the surrounds are intact, if slightly tacky. The oiled walnut cabinets are also in good condition with a tiny veneer chip on one top front corner. The grills are originals, with small holes in the two fronts; the tops are better with minor flaws only along the edges. Very presentable. Anyway, I’ve been selling some of my excess equipment, and have already sold three speaker pairs plus a center channel plus assorted electronics as I remake my A/V systems. This one is just next on the list. Asking $275 for the Allisons - about what standard Allisons go for without such modifications.. Will consider offers, but if I don’t get a fair price I’ll just give them to a sibling. Finding a shipping box this large won't be easy, so I'd prefer a local sale.
  8. rnathans00

    Need CD-7 crossover schematic

    Pretty well. The tweeters were replaced with SB Acoustics SB29RDC, which required some cutting to expand the tweeter opening. Attached is a shot of the new crossover, which I mounted on the inner panel behind the tweeter. There seems to be a bit more dynamics in the treble range, a tad less dispersion perhaps. But I can't confirm until I do proper testing until I've corrected some of the acoustics in my listening room. Not really using it much, as I've moved to Revel M22 and Totem Sttaf as fronts in my two listening rooms. I hate to use them as just surrounds, so if someone in the Washington/Baltimore area is interested in some nice Allison hybrids, they're available for sale. (Still have one of the original Allison tweeters, which is in good shape and tests well - unlike many samples offered on eBay.)
  9. rnathans00

    Best height for Allison CD-6

    I've long wondered about the best height, given that the CD-7 floor-stander, at only about 27", puts the tweeter well below ear level. But a CD-6, put on a typical 24" stand puts the ear at 90 degrees to the woofer, so we're hearing output from said woofer only by reflection while we're hearing the tweeter directly. The woofer is already starting to "beam" before it reaches the 2000 Hz crossover, and it continues well beyond that point given the 6 dB per octave rolloff of the simple coil-and-cap crossover. If I put the CD-6 on, say, 18" stands the tweeter will be a tad higher than on the CD-7 but at least I should be seeing and thus hearing more of the woofer directly. Before I set out to make stands at that height has anyone experimented with heights and found an optimum for this series? Thanks.
  10. rnathans00

    Need CD-7 crossover schematic

    Well, here's a major update. Suspecting there was more to my problematic CD-7 than just a capacitor, I contacted someone prominent in the amateur speaker building community (he's helped design some well regarded ID speakers) and he offered to look at them. Low and behold, the trouble speaker had a tweeter whose response was all over the place. (The other was remarkably well behaved by comparison.) We decided to do a full overhaul. Since it would be tough to find another Allison tweeter that closely matched (unless I scrounged from my working CD-6 pair), we're replacing *both* tweeters with something more modern, and he's designed a more complex crossover with a lower crossover point. I'll be picking it up within the next few days and will report on the results.
  11. rnathans00

    Need CD-7 crossover schematic

    It appears there's at least one additional component on this crossover - a little (blue) component I suspect is a bridging capacitor. What's the best way to remove or dissolve that hard wax goop?
  12. rnathans00

    Market value of classic Allison One towers

    Oh, I wish I could have gotten that kind of money for mine. I didn't have original packaging, and after several weeks posted on both Audiogon and Craigslist, I drew interest from only one local party. I was already interested in some lightly used Revel M22 stand-mounts and didn't want to lose out. So I sold the Ones for far less than suggested above, but I got the Revels at a good price. I still have a pair of CD-7s, which I'll either sell or pass on to a sibling. But I'm keeping my CD-6 cubes.
  13. Folks like Snell and Revel were known for testing production speakers against a design reference to better guarantee that speakers would sound like they were supposed to. But such consistency was never baked into earlier speakers, even those we still regard highly today. As I've been shuffling surplus speakers around, to decide which I would be keeping and which selling, I decided to put a pair of Allison CD-7s along one living room wall, one of whose positions has always been troublesome because of close reflective surfaces. But this one sounded especially bad during the Audyssey sweep. Was it the crossover? Was it the age of this 1980s vintage speaker? Was it just the fact that speaker builders back then didn't especially concern themselves with variations in drivers and components? I decided to run a simple test. Yes, I know these were not laboratory conditions, and I can certainly do better, but this was a quick-and-dirty. With each speaker about 20" from the back wall, I placed a microphone at tweeter height about 18" away. I fed a series of sine wave tones generated by Performance Audio Tone Generator Pro through a Denon 2802 receiver. I used a simple plug-in mike to my iPod Touch, using JL Audio's SPL meter for readouts. With just one speaker running at a time, here's what I got: Frequency Speaker A Speaker B 100 37.3 35.9 250 40.3 43.7 400 48.9 48.5 1k 56.6 53.7 1.6k 49.6 54.4 2.5k 48.4 38.0 10k 55.0 49.7 WHITE 75.0 71.6 PINK 85.1 81.8 So Speaker B - the one that sparked this investigation - registers a bit more bassy at 250 (room reflections due to different placement perhaps), but notably down at 2.5k - just above the 2000 crossover) and also down in the upper treble. White and Pink noise results are also lower for Speaker B. Assuming these results are replicated under more precise conditions, what conclusions might be drawn? Does the lower tweeter performance suggest the crossover cap be replaced? Or is this just sample variation? Obviously if there is that much variation between the two, it's not surprising the Allisons don't image as well as my Outlaws, my old Celestions or my new Revel M22s.
  14. rnathans00

    Need CD-7 crossover schematic

    So I was right - it is more complex than that of the CD-6 with the addition of that second inductor across the tweeter. But it does appear to use the same value capacitor as the CD-6. (I replaced a problem capacitor on one CD-6 with a better but low-cost ERSE.) I need to do a little more testing, but it appears one of my CD-7's tends to be 'bass'ier' than the second, so maybe I'm just not getting the right amount out of the tweeter. (Both woofers are intact.) The trick of course, should it prove necessary, will be getting that crossover/terminal plate disconnected from the drivers and clearing away some of that wax goop so I can work on it. I presume need only worry about the cap. Thanks.
  15. rnathans00

    Need CD-7 crossover schematic

    I've worked on the crossover of one of my CD-6 cubes, but now I'm going to take a stab at one of my CD-7 minitowers. But though they have the same drivers, the crossover looks more complex, with more components bunched together behind the speaker terminals. Can anyone point me to the schematic? Thanks in advance.