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Dave MacKay

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Posts posted by Dave MacKay

  1. 1 hour ago, henry4841 said:

    When you go to someone's house you play by their rules. Rules have changed and some do not like it. I get it but it is still their house we play in. 


    Through our purchases we paid for the house. 

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  2. 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.


    • Like 2
  3. 5 hours ago, Tom05 said:

    Hi Dave , there’s different ways to do it , if I’m not mistaken you went with horn subwoofers , which  is a good way to go , you get the Impact and the output , the quality ? I send all bass and LFE  to   full range Khorns and  augment them with a parallel  signal to a bunch of ported subwoofers located at the rear  of the room. This works well and the khorns  sealed back chamber seems to tolerate the situation just fine . Even when I had a horn sub I ran full range 



    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.

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  4. 3 hours ago, Tom05 said:

    What you said here is important ,  I agree completely , just to further  emphasize , if ANY of the Lascala bass output is being  passed to a subwoofer,  great care must be taken to ensure that  there is no loss of IMPACT  , OUTPUT or QUALITY to what the Lascala was  providing , we must be careful not to make negative compromise to the Lascala  sound .This also applies to Klipschorn 🤓



    @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?

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  5. 16 hours ago, nickyboy6100 said:

    Dave, how much do the THTLP’s bring to the table when paired with the La Scala’s? Ive considered pairing a horn loaded sub with mine for years. I’ve just never pulled the trigger. I’ve had larger Klipsch pro speakers in the past and miss the low end they provide. 


    @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. 


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  6. 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.

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  7. 34 minutes ago, Peter P. said:

    What's that thing in the corner; is that a subwoofer?

    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.

  8. On 1/24/2022 at 10:38 PM, Dave MacKay said:

    What a coincidence!  I've been wondering if risers would be of benefit to my 1986 La Scalas. I wasn't thinking of bass, just about getting the speakers closer to ear level when I'm seated.


    Just today I went through my notes about the AL5 risers because I was thinking of making some for my 1986 La Scalas. If my notes are correct, the AL5 risers are 3" high and are made of 1" MDF (just like the AL5). 


    When the snow stops I was thinking I'd rummage through my wood pile and make a pair of risers just to see if they make any difference.


    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.

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  9. On 12/3/2021 at 1:11 PM, Dave MacKay said:

    All told, my ~US$2200 La Scalas will end up costing about US$3400. 

    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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  10. On 11/26/2021 at 2:18 PM, Dave MacKay said:

    I was able to find the terminal strips I was looking for at an electronics surplus shop. In case the information might be useful for others, I'll share the product information here.


    They are made by CINCH Connector Division and are called a "barrier block". They are CINCH part number 2-142. Here's the web page that describes them:


    I have learned that the barrier block I purchased was mislabelled at the store. Although the CINCH 2-142 will work, it is larger than what was originally used on the La Scala (and other Klipsch speakers). 


    A more suitable part is the CINCH 2-141. The CINCH 2-141 takes a #6-32 x 1/4 machine screw and can accommodate up to 14 AWG wire. I do not know if the part originally used by Klipsch was a CINCH 2-141. Although similar, the 2-141 does not have the markings that the barrier blocks on Klipsch speakers had. 


    An alternative to the CINCH 2-141 would be the Marathon Special Products 601 GP 02.


    Other barrier blocks that might be suitable are the Eaton-Bussmann TB200 (TB200-2, TB200-2BS, or TB200-2B) or the Molex Beau 38780-0202.

    • The datasheet for the Eaton-Bussmann part doesn't specify if the back is open or closed (we want open). [I contacted the company and learned that it has a closed back so that one would have to drill through.]
    • Although the Molex part has a closed back (which one would have to drill through) it can be ordered with markings similar to what Klipsch used.

    I have attached datasheets for the Cinch, Marathon, and Molex barrier blocks. The datasheet for the Eaton-Bussmann part is too large to upload. It can be found at: https://www.eaton.com/content/dam/eaton/products/electrical-circuit-protection/fuses/bussmann-series-connector-products/double-row-connectors/bus-ele-cat-1007-flc-2017-sec-10-connectors.pdf



    Molex - 387800202_sd.pdf Cinch 141.pdf

    Marathon (Newark) 601-GP-02.pdf

  11. I have tried using DSP to address flaws in my listening room and to integrate subwoofers in my system for better bass. My experience may be ill-formed, but ...


    What I have found is that where and how much one can apply DSP is dependent on the equipment you have and how it is configured.

    • If you don't have a pre-amp or receiver with pre-outs, your ability to tune your system with DSP will be pretty much confined to what your receiver manufacturer provides (e.g., via Audyssey, DIRAC, or YPAO) and integrating subwoofers. Not all systems (even within a the same brand) provide the same capabilities, allow much tailoring by the user, or show what processing is being applied.
    • On the other hand, if you are bi-amping or tri-amping you have the flexibility to bypass the networks in your speakers and do whatever you wish.

    In my case, I don't have much ability to apply DSP to my mains. My Yamaha R-N803 receiver allows me to turn YPAO on or off and set distances and gain, but that's about it. It doesn't show what it's doing; it operates as a black box. That pretty much restricts my ability to apply DSP to the LFE (i.e., subwoofer) signal.


    I split the LFE signal and send it to two subwoofers. Although I started with the DSP capabilities provided by the plate amps (SPA250DSP) that power my subwoofers, I found those capabilities to be limited (no ability to set delay, for example) so that I ended up sending the LFE signal to a MiniDSP 2x4HD (which is far more capable) and feeding the the plate amps from it.


    I've used a measurement microphone (UMIK-1) and REW (Room EQ Wizard) software to assess what DSP to apply and to program the MiniDSP 2x4HD. However, I've not yet achieved results that I find pleasing. Others, such as @wuzzzer, have had much better --- indeed superb --- results.


    What you need to spend will depend on what you have, the problems you choose to address, and how far you want to go. You're likely looking at >US$400 to get started: the REW software is free (it's funded by donations from users), a UMIK-1 is about US$110, and a MiniDSP 2x4HD is about US$300.


    I'll look forward to what others with more knowledge and experience have to say. 

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  12. 1 hour ago, Marvel said:

    Do your cabinet backs have the Klipsch labels? The barrier strips might have been on the top and were rotated to have the installed cups toward the bottom.


    That’s an interesting suggestion.


    My speakers only have remnants of the labels remaining. What is there is located towards the upper right-hand corner of the backs. The surviving text is the right way around which would indicate that the backs haven’t been rotated (unless the labels were removed and repositioned).


    Apart from the screws, there are no holes — or signs of holes that have been filled —- on the backs. That makes me think that what @jcn3 related about his ‘84 Heresy’s may also be applicable to my ‘83s.

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  13. 1 hour ago, jcn3 said:


    @Dave MacKay -- the location of that barrier strip has been all over.  On my 75 Heresy 1, it's towards the top as described above, but off to the right.  I just picked up a pair of 84 Heresy 1.5 and the barrier strip is located where your binding post cup is.  I can get a pic later tonight.



    That fits with what I see on my speakers. There aren’t any screw holes visible at the top of the cabinet backs which supports the idea that the barrier strip would have been located where the cut out was made for the binding posts.

  14. I'll be restoring my new-to-me 1983 Heresy 1 speakers. 


    My speakers have rectangular binding post cups to connect the speakers to an amp. Here's a photo (the cup is circled in red) of what I mean:


    The cut-outs for the binding post cups are fairly rough, which made me wonder if they might have been installed by a previous owner rather than at the factory. Would binding post cups have been original to the Heresy?


    Or would the Heresy have used a barrier block similar to this:


    If so, where on the back of the speaker would the barrier block have been located? (I assume it would be centred where the binding post cup is now).

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