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Dave MacKay

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Everything posted by Dave MacKay

  1. Have you taken any measurements, e.g., with REW? If so, please share a plot that shows the performance measured with each autoformer.
  2. Looks fabulous! Congratulations on a lovely job.
  3. Is it possible that your father (or the first owner) made some mods? Several things are different from my La Scalas (which date from ‘86, so a dozen years later than yours): Is access to the woofer & doghouse from the top (rather than the bottom)? It appears that the network is mounted on (what looks like) an access panel. Mine have the access panel on the bottom. The panel is a little smaller than the base so that the speaker appears to float on it. My networks were not screwed in; they just sat loose. The support for the squawker driver is different. Mine is bent aluminum, not painted. Mine don’t have the filler panels partially enclosing the sides of the rear opening. There is no evidence of screws being used on the top of my cabinets. Other members will know more and may be able to provide a definitive answer.
  4. Thanks. You're right about not being able to make any sense of this! I've been going through Dickason's Loudspeaker Design Cookbook, but have been finding it hard slogging. Do you have any suggestions about learning materials/resources?
  5. Like @mboxler, I'm confused too. I've been trying to understand how the 1st order filters used in the woofer section of the A and AA networks work. The filter consists of just a 2.5 mH inductor. When I calculate the crossover frequency into the K-33E (which is rated at 4 ohms), I get a crossover frequency of 250 Hz, not the 400 Hz that I was expecting. Even if the K-33E was 8 ohms, the filter would crossover at 510 Hz, not 400 Hz. I know that driver impedance isn't constant, and that it varies with signal frequency. When I vary the woofer impedance based on a curve that @Trey Cannon posted sometime ago, I find that the crossover frequency varies between 220 Hz and 1210 Hz in the frequency range applicable to the woofer. I had hoped for a nice clean drop-off starting at a specific frequency, but that doesn't seem to be how the filter works. i thought that higher impedance = higher crossover frequency = more attenuation = lower SPL but that's not what my REW measurements show. I must be failing to understand something. What am I missing?
  6. I've answered my own question. I'll post the answer in case it helps others. I reached out to repairparts.ca (a division of Microland which is a subsidiary of Gentec, Klipsch's Canadian distributor). They were happy to make arrangements to bring the parts in from Klipsch USA. Because they don't stock the parts locally, it will take about 4 weeks for them to arrive, which was just fine with me. To my surprise, the price was very good --- considerably lower than if I'd purchased from a well-known (but unnamed in this forum) supplier in the USA, even before considering currency exchange, shipping, and customs duty. The lesson I take from this experience is that --- if you know the Klipsch part number of what you're looking for --- it's worth checking with Klipsch.ca (operated by Gentec) instead of defaulting to a third-party supplier.
  7. Thanks. Do you know if they will sell to Canada? I’m in Canada where Klipsch service handled via Gentec, Klipsch’s Canadian distributor. Gentec (also operating as Klipsch.ca) refer parts queries to an affiliated company (www.repairparts.ca). Unfortunately, the gaskets aren’t listed on the repairparts.ca website. I’ve e-mailed them to ask if they can supply the gaskets.
  8. Where can the gaskets be purchased? What size & material?
  9. @ClaudeJ1 and many others are active on “Klipsch Korner” of the Audiokarma forum.
  10. What about other than tech support? Called tech support because it was the only phone number listed on their web site. Tech support said they’d get Sales to call to let me know where to find a dealer. Nothing. No response e-mails sent via their website’s “Contact us” either. Seems they’re uninterested.
  11. I, too, was interested in Xilica (in my case an XP 4080) but I’d be cautious before purchasing. Xilica’s website lists the XP 4080 as a “legacy accessory”. I’ve not been able to get a response from the company despite several e-mails and phone calls. Given that level of commitment to the product, I’d suggest looking elsewhere.
  12. My 2 cents … - more than 1 sub provides a great deal more capability in taming room modes (esp. below the. Schroeder frequency). I’d suggest either 2 or 4 subwoofers - use a MiniDSP 2x4HD to integrate the subs - horn loaded subs are available, but often involve DIY. Check out Bill Fitzmaurice’s designs. I built 2 of his THTLPs and have been very happy with them - consider other brands than Klipsch for subs. Klipsch does many things well, but I’ve not been impressed with their subs.
  13. In my experience having multiple subs (I have 2 in my listening room) made it possible to tame (to a certain extent) room modes. However, dialling them in can be challenging. I needed a MiniDSP 2x4HD to get them set up suitably. YMMV.
  14. Through our purchases we paid for the house.
  15. The PCB is so crowded with the new components that it sure looks difficult. Just wondering if it might make sense to make new, larger PCBs. They can be drawn up with free tools like KiCAD and made quickly and cheaply by companies like PCBway. That might make the job a whole lot easier without incurring much additional cost.
  16. Too soon to tell, but my initial impression is that I couldn’t hear any difference. I didn’t think to take measurements with REW before and after to see if there was a measureable change.
  17. If you decide to do it, you’ll want to use a thin gasket. I was able to use 3/16” thick foam tape but it required a lot of force to get the rear panel to sit flush. I plan to get some 1/8” thick tape and re-do it.
  18. I’m refurbishing a pair of 1983 Heresy speakers that I bought a few weeks ago. I was surprised to find no evidence of any acoustic gasket between the removable rear panel and the speaker carcass. On my La Scalas, an acoustic gasket (foam tape) is used to seal the woofer access panel. Did the Heresy 1 have acoustic gasket on the rear panel? Or was it not necessary?
  19. Thanks. You have a good memory: I have a pair of THTLP subs with my La Scalas. I think I’m doing what you’ve recommended, at least to the extent that my knowledge (and equipment) permit. I run the La Scalas as “large” so that the entire audio signal —- including the bass —- is sent to them. The subs are fed a signal from the “subwoofer out” on my receiver via a MiniDSP 2x4HD. Although I’ve been experimenting with crossover frequency (anywhere from 40 Hz to 110 Hz), currently the subs are crossed at 80 Hz.
  20. @Tom05 What would you recommend to ensure those things? Would simply running the La Scalas as “large” (i.e., full range) speakers in the amp set up accomplish that?
  21. @nickyboy6100, I've been quite pleased with the THTLPs and how they fill out my La Scalas. Prior to making the THTLPs, I had an inexpensive Klipsch subwoofer (repurposed from a Klipsch Synergy home theatre). It did nothing. I replaced it with an SVS SB-1000 Pro subwoofer, which I liked quite well. However, I'd read comments from @ClaudeJ1 that, in his opinion, a THTLP was a great sub for La Scalas. Because I was looking for a COVID project, I decided to make one. My listening room suffers from a number of acoustic deficiencies such that I couldn't get consistent good sound from a single subwoofer --- neither the SB-1000 Pro nor the THTLP. Since I'd enjoyed building the first THTLP, I built a second. Adding the second subwoofer (in the corner diagonal to the first THTLP) helped tame the room quite a bit. Despite having the two large THTLP subwoofers, I still wasn't entirely happy with the sound. I knew that most of my dissatisfaction stemmed from the room itself, and WAF limited what I could do in terms of room treatment. I added a MiniDSP 2x4HD to drive the subwoofers. The MiniDSP 2x4HD has been fantastic. I would recommend a MiniDSP for any multi-sub configuration. I used REW to measure the effect that the THTLPs have on my system. This graph (with 1/3 smoothing applied) shows both: a 20-20KHz sweep of my La Scalas only (in brown), and a 20-20KHz sweep of the La Scalas with the THTLPs (in blue) I've tinkered with placement, room treatment, and MiniDSP settings since taking those measurements so that my system now performs a little better. This graph (no smoothing) shows a 20-200Hz sweep (i.e., the frequencies affected by the subs) before and after making those changes: @wuzzzer has a similar configuration (i.e., La Scalas with THTLP subwoofers). From what he's posted, I think he has achieved results superior to mine. With respect to how much the horn-loaded subs bring to the La Scalas ... I don't know how to answer. In truth, the little SVS SB-1000 Pro is a dandy little sub. However, I didn't take any measurements to quantify how it performed with the La Scalas. I might well have been happy with a pair of them (or their larger siblings). Certainly the THTLPs have brought loads and loads of low-end to my system. They are efficient (which I hope brings low distortion), quick, and clean sounding. I tend to listen at modest volumes (typically < 85 dB). Even though my THTLPs are the smallest size (15" x 18" x 72" with 12" drivers) and are driven by small (250W) plate amps, I've never come close to their limits. Even when showing off, I doubt I've ever pushed 50W through them. Perhaps @ClaudeJ1 or @wuzzzer might be able to provide you with more informed perspectives.
  22. Here are the REW measurements that show the affect that adding risers to my La Scalas had when measured at my listening position. I have applied 1/3 smoothing to the graphs. The risers (blue line) raise the La Scalas just over 5" so that the tweeters are at the same height as my ears (roughly 40") at my listening position. From the graph, it looks like the frequency response is flatter without the risers (perhaps the risers exposed more problems with my room's acoustics). The measurements show that the riser brought a bit more volume. Although I tried to keep all of the measurement parameters the same, they were done several weeks apart. It's possible that, maybe, the volume settings were different. If that were the case, if one were to turn up the volume on measurement without the risers by 4 dB, the graph would look like this: The graphs show that the risers didn't bring much benefit; the SPL graph is flatter without risers. Even if the risers did result in higher SPL at the listening position, the effect was generally modest (~4 dB). I thought that the speakers sounded better with the risers but the measurements belie that. I'll use the risers for a while longer, but they may not have a permanent place in my listening room.
  23. In the corner to the right is a DIY bass trap. In the corner to the left is a THTLP subwoofer. I have 2 THTLP subwoofers in the room. The second THTLP is in the corner diagonal to the one in the photo.
  24. It took me a while, but I finally built risers for my La Scalas. I made them tall enough so that the tweeter is at the same height as my ears at my listening position. For me, that meant building risers slightly more than 5" tall. I thought the speakers sounded a little better in that the music sparkled a bit more. But, that could simply be because I was hoping to hear an improvement. 🙂 I have not yet run any sweeps with REW; I'll post the graphs when I've done that.
  25. Actually, I ended up spending about 40% more than that. After all was said and done (new crossovers, replacement tweeters, laminating plywood to cabinets, making risers, veneering and finishing), I ended up spending about US$4700 to purchase and refurbish my La Scalas. I don't regret a penny of it.
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