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Dave MacKay

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Everything posted by Dave MacKay

  1. If you do, and if you have the necessary gear, would you please take some measurements with REW before and after making the change? I'm interested in this topic but (unless I missed something) all of the feedback about improvement has been anecdotal and subjective. I'd find it interesting to see the actual difference that the damping makes.
  2. Most of the restorers I spoke with were not keen on doing veneer. I think that their typical work involves stripping and refinishing so that they didn't have the tools (e.g., vacuum press) that they felt would be needed for a large veneer job. The only one (Johnny's) that was prepared to consider the work has a wait list of about 6 months. He estimated that veneering and refinishing my La Scalas would cost about $3000. At the time I thought that was high (I only paid $2800 for the speakers) but I've come to appreciate that it was likely pretty reasonable. If you'd like to bounce ideas, share tools, or work together send me a PM. I'm in the Port Credit area of Mississauga.
  3. That would be fantastic! If held on-line (e.g., as a Zoom session or a pre-recorded seminar) people could participate from anywhere.
  4. Are you sure it's ouputting AC, not DC? Almost all LEDs require DC, not AC. Also, it would be very odd to use 4 AA batteries to produce AC (at any frequency).
  5. You misunderstood the intent of my post. Not all spaces will accommodate an ideal configuration. Mine won't. I wanted to explain what I'm working with, and what I've done to try to improve the acoustics. Short of selling my house, or moving walls, doors and windows, do you have any suggestions that might be applicable for my space?
  6. I'm sure you have a point, and I welcome the suggestions. Unfortunately, some of them aren't feasible for my space; I'm working with what is viable, not what would be ideal. My listening room is 22'4" long x 11'7" wide x 8'2" high. In the centre of one of the long walls is a pair of french doors; there is a fireplace opposite it. The short wall has another set of french doors at the rear, and a large window (plus hot water radiator) at the front. I regard the Main Listening Position as being mid-way between my wife's chair and mine. That point is in the centre of the room, about 2/3 of the way from the front. It's far from an ideal listening space. But it is what I have to work with. Some of your suggestions aren't feasible for my space. For instance: My La Scalas won't fit in the corners of my room because of the space taken up by the hot water radiator that heats the room. Since I can't put the subwoofers in the middle of a doorway and a window, I've put them in diagonal corners. The other corners have floor-to-ceiling bass traps. Although I don't have an equilateral triangle between the speakers and the centre of my listening position, I'm pretty close: instead of 60-60-60, I have about 70-70-40. Putting the chairs in the centre of the room would interfere with the ability to move around the room (because of the space taken up by the doors and the fireplace hearth), so that the listening position is back from the centre of the room. However, the distance from the listening position and the speakers is close to the same as it would have been if the speakers were in the corners and the listening position was in the centre of the room. The La Scalas are toed in so that they point at the listening position. That's about 25-30 degrees. The electrical polarity of my speakers (and drivers) is correct. Unfortunately, I currently lack the means to add a delay between the speakers and subwoofers.
  7. I hope you have better luck finding such a professional than I did. I called all of the furnture restorers within a reasonable radius (I live near Toronto, Canada) trying to find one to veneer my La Scalas. None would do the work. As a result, I'll be doing the veneering myself.
  8. It may be that the YPAO capability is differentiated (gets better) as one goes up Yamaha's product line. My experience with a lower-end Yamaha receiver has been that YPAO improves performance above 1 kHZ but significantly impairs bass performance (below about 150 Hz). Here's a link to the post where I shared what I measured (red line on chart uses YPAO settings; the blue line on chart is "pure direct"):
  9. @ricktate What veneer is shown in the photo? Also, what finish? It looks good. I plan to do something similar to my La Scalas. They are Raw Birch and had been coated with polyurtehane. To repair some damage (and address resonance) I stripped the finish and laminated 3/8" Baltic Birch panels to the top, bottom and sides. It turned out nicely, but they aren't cosmetically as appealing as I'd like. I haven't been able to find anyone to veneer the speakers, so that I'll do the veneering and finishing myself. However, I'm concerned that my skills aren't up to the challenge of veneering the bass bin. For that reason, I was thinking about just applying a fresh birch veneer so that I could leave the bass bin as it is and have a reasonable match. I like the look of what's in the photo. Did you veneer the bass bin along with the rest of the speaker?
  10. My experience, albeit with a different tool, has been similar to yours. I found that the Yamaha YPAO on my receiver made some odd settings, and that I couldn't override some of them. I've stopped using YPAO and am now running in "Pure Direct" mode where the input signal completey bypasses all processing and tone controls. I'm using REW and an external DSP to tailor the sound to my room.
  11. Room is 22' 4" long x 11' 7" wide. Ceilings are 8' 2". Two La Scalas are on the short wall. One THTLP subwoofer is in the corner behind one La Scala, the second THTLP subwoofer is in the diagonal corner. No room treatment (yet) but it's definitely needed.
  12. Here's a photo: I plan to veneer and refinish the speakers this spring.
  13. You can hardly go wrong. I have an even less expensive Yamaha (R-N803) driving my La Scalas. It addressed almost everything I wanted (except a pre-out and HDMI input) for CAD$999. You could likely find it for less. If I were to replace it, I would certaily want to try some of the new low-cost SS amps like Aiyima or the Topping PA5, which have had rave reviews on this forum. In any event, there's no need to rush into anything. Your new speakers will sound fine with what you have.
  14. I found that Yamaha's YPAO system made it much harder for me to integrate my subwoofers with my La Scalas. I ended up running my Yamaha receiver in "Pure Direct" mode (where all EQ and tone controls are bypassed). Try doing the same and see how it affects the sound. I would recommend that you download REW (Room EQ Wizard, it's free) and get a calibrated mic (e.g., UMIK-1) so that you'll be able to see exactly what your system and room are producing. With that, you'll be able to proceed systematically.
  15. I appreciated the step-by-step approach. I've been learning REW for the past few weeks. It's a wonderful tool, but I find it very complex. It relies upon the user having a level of audio and mastering knowledge that I'm lacking. Clear, simple explanations help newbies like me.
  16. The woofers are the original (1986) K-33-E. The screws on the access panel are tight. I will be replacing the gasket (which is original and is squished as thin as a playing card) with some 1 1/4" wide x 3/8" thick closed cell gasket tape when I veneer and refinish the speakers this spring.
  17. I’d like to thank the members of the forum (@henry4841, @yamahaSHO, @wuzzzer, @billybob, @captainbeefheart, @hanksjim1, @Shakeydeal, @Crankysoldermeister, @babadono, @Rudy81, @garyrc, @Rolox, @NBPK402, @RandyH, @pbphoto, and @Kalifornian) who contributed to this thread. The suggestions tended to deal with EQ, phase, speaker placement, and room treatment. · Given the layout and furnishings of the listening room, my options for placement are rather constrained. · Certainly, the room does need some acoustic treatment. In time, that will be addressed. · I’ve verified that the polarity of the AA networks and all of the drivers , including the woofers, is correct. · I’ve stopped using the EQ capabilities of my receiver and am now operating in Pure Direct mode (which bypasses all EQ and tone controls). My goal was to “dial in” my La Scalas before adding (and EQing) my two THTLP subwoofers. For the purposes of this exercise, I configured the amp for stereo only (no subwoofer). Initially, I used only a small set of the YPAO (Yamaha Parametric room Acoustic Optimizer) capabilities of my Yamaha R-N803 receiver. I thought that all I was doing was setting the distances and levels from the speakers to the listening position. I referred to this configuration as “YPAO neutral”. When I followed up on suggestions from @wuzzzer and others, I found that the YPAO was altering the signal quite a bit: it boosted the low-mids and high frequencies, but diminished the bass substantially. · the low-end performance of the La Scala dropped precipitously below about 200Hz and was pretty much non-existent below 100 Hz · frequencies above 1 kHz were boosted by about 5 dBFS · frequencies between 200 Hz and 500 Hz were also boosted I then turned the YPAO off and re-ran the tests. Finally, I put the receiver in Pure Direct mode so that the receiver bypasses all signal processing and routes the input signal directly to the amp. The YPAO and all tone controls are completely bypassed. This graph shows the results of the tests. For clarity, I averaged the results from each of the 3 microphone positions for each test and applied 1/6 smoothing. · The red line shows the results from the first (YPAO neutral) tests · The blue line shows the results from the YPAO off tests · the green line shows the results from the Pure Direct tests There appears to be little discernible difference between the YPAO off and Pure Direct amplifier settings. Both are a significant improvement over the results when the YPAO system was enabled. With my Yamaha R-N803 receiver configured in either YPAO off or Pure Direct mode, my La Scalas perform +/- 5dB from 64Hz to 18.5 kHz. I’m pretty satisfied with that. My next challenge will be to blend my two THTLP subwoofers with the speakers. Fortunately, that may not be as hard as I feared since, according to Yamaha, in Pure Direct mode the receiver still sends 100 Hz and lower to the subwoofer output. Since it’s clear that my room presents challenges at low frequencies, I expect I’ll need to make use of the EQ available from the SPA250DSP plate amps that power each subwoofer. Thanks to all for your help.
  18. Here is the 20 Hz to 20 kHz graph with 1/6 smoothing. Blue is the base case (YPAO off) and red is the base case with the phase of one woofer swapped. Here's a zoom-in from 20 Hz to 200 Hz of the same graph: What should I look for when measuring the speakers one at a time?
  19. The room certainly has issues and needs treatment. Because of WAF placement and room treatment are matters for negotiation. I'll discontinue using YPAO. I'll have to figure out how to meld my subwoofers into the system, but that's a challenge for another day.
  20. To see if the woofers in my La Scalas might be out of phase with each other, I reversed the positive and negative leads going to the woofer in my Right speaker. I flipped the leads at the network, as @captainbeefheart suggested. TLDR, I’m not sure but I think the woofers were in phase. I ran the test in direct stereo mode (i.e., all YPAO equalization turned off on the receiver). I’ve overlaid the base case (i.e., leads not swapped) in blue with the test case (i.e., leads swapped) in red on these graphs. The graph shows the results of that change: The blue and red lines are pretty close together above 125 Hz, but show some separation below that. Here’s a zoomed in portion of the graph, showing 20 Hz to 200 Hz: It seems to me that the blue lines (i.e., not swapped) look better. From these graphs, is it possible to tell if my woofers were out of phase? I’m guessing they weren't, but am not sure.
  21. I re-ran the “base line” test after ensuring that all YPAO equalization on my receiver was off. TLDR, performance was more consistent, a little worse at high frequencies and somewhat better for bass, but bass is still weak. I have overlaid yesterday’s results (in red) and today’s results (in blue) on the same graph. Here is the graph from 20 Hz to 20 kHz: What I noticed was: · frequencies between about 500 Hz and 1000 Hz are about the same · frequencies above 1 kHz have dropped by about 5 dBFS · frequencies between 200 Hz and 500 Hz are also lower · although the drop-off below 200 Hz is still there, the slope is less steep Since we are concentrating on the low frequencies, I have zoomed in to the portion of the graph between 20 Hz and 200 Hz: There is no question that today’s results (in blue) are better than yesterday’s results (in red). Today’s results show that: · my La Scalas perform at about -50 dBFS +/- 5 dB from 100 Hz to 17 kHz. · bass performance drops precipitously below 100 Hz. It’s down more than 10 dB by 50 Hz. · the La Scalas (with SMAHL tweeters and lenses) drop off slightly after about 17 kHz. That’s not a concern for me because it’s outside my hearing range. From this, it’s clear that, although the Yamaha YPAO system improves performance above 1 kHZ, it significantly impairs bass performance. I had wanted to be able to use YPAO because it enables me to specify where a cross-over frequency for LFE. And, sadly, the receiver’s user manual doesn’t specify what is sent out the LFE and when. I may have to contact Yamaha to see if I can continue to use the LFE output for my subwoofers, or if I’ll need to connect them in another fashion. I’ll make another post with the results from flipping the woofer wiring on one speaker (to investigate phase issues).
  22. Visually, the speaker wiring from the amp to the networks, and from the networks to the drivers is correct. I can double check everything (except the network to woofer wiring) with a multimeter. I'd prefer to avoid having to flip the La Scalas upside down and remove the access panel to check the woofers until I've ruled out other possibilities. I could run the test with just one speaker to see if I still see the bass drop when testing the speakers one at a time. Would that be worthwhile? The YPAO on the receiver gives an out of phase error, but that's apparently pretty common. Since the wiring is correct, I figured the "out of phase" warning had to be due to reflections from hard surfaces in the room.
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