Jump to content

PrestonTom

Regulars
  • Posts

    4317
  • Joined

  • Last visited

Everything posted by PrestonTom

  1. Well, it depends if you are in a hurry and If you are comfortable buying used. My last place was 11 ft wide (and 27 deep). I had Jubilees in that room and the sound was fantastic. Klipshorns would also work (they do need corners or false corners). These two models become affordable when they are on the used market and will sound considerably better than many of the suggestions above (IMHO). Good luck, -Tom
  2. There is an obscure area of (auditory) science referred to as psychoacoustics or auditory psychophysics. The endeavor attempts to manipulate changes in the physical stimulus (things that can be physically measured - eg amplitude spectrum, dispersion etc) and to measure the corresponding psychological consequence (percept - eg, was it "louder", "better", could you detect the change, etc). In this case, Toole surveyed a number of existing speakers for their physically measured properties (physics) and looked at the corresponding psychological response (in this case .... on a 1 to 10 scale "how good does the speaker sound"). This later measure (psychological) is not trivial to measure, since there are number of ways to do it "wrong". However, Toole knows what he is doing so I am not troubled by the techniques that he used. The outcome was that he was able to weight various physical measures, (amplitude response, dispersion, etc) and do a decent prediction (via correlation) on how well (numerically) the listeners would rate speakers regarding sound quality. Notice, this is an empirical approach with little theorizing on "why" the various factors are weighted high or low. Not much "interpretation" going on ..... So have a look at Toole, he is pretty good at simplifying things for a general audience.
  3. Posting photos would help a great deal. Are they currently set up so buyers could audition them? There are so few that come up for sale that it is hard to guess on price.
  4. VDS, Have you read Toole's book. Some of it is subtle and needs to studied. What did you think of his overall approach and conclusions? It is a worthwhile reference but the "what and why" is not easily summarized. Good luck, -Tom
  5. You are thinking of someone else. I tend to be old school when it comes to electronics
  6. First, take Edgar's advice. It is quick and simple and can help pinpoint the problem Although, didn't "we" already eliminate this problem a few days ago? BTW, has the sloppy grounding on the "Rawson" Amplifier been cleaned up yet?
  7. Since the F3 is a Rawson build, I am very suspicious. Let's hope this mess can get cleaned up.
  8. VDS: Please clarify a couple of things. Is the Pass amp a DIY or a factory version (what I am getting at is whether the input grounds are directly or indirectly electrically connected to the amplifier chassis). The shield on the RCA side of the cable is electrically connected to Pin 1 on the XLR. However is the mechanical connection at the RCA side or the XLR side (or both). The reason I ask (and this is a remote possibility) is whether the the "third wire" is not connected on one end then it could be acting like an antenna and picking up junk (not a technical term). In either case "fixing" the cable can help things (whether it is ferrite acting as a filter, or a transformer isolating any small potential difference (voltage)). This is why I say this is ultimately a cable issue and not an amplifier issue. The reason some of us are having difficulties is that bad cabling usually results in low frequency junk (hum etc). Your problem is a bit different. As an anecdote, I used to work in auditory labs (science kind and not the recording kind ...). Mixing balanced and unbalanced equipment was always a nagging problem (not every time, but occasionally). We would all come through the set up when there was a problem and frantically swap cables, power cords, toggle "ground float switches" etc, etc. Eventually, the circuit would quiet down (after going through an endless combination of wire / equipment swapping) and someone would proclaim: "see I told you so .... it was a ground loop" (although they never actually pin-pointed the culprit). BTW, if you look at the schematic of what the Jensen ISO unit is, you can mimic it for less money although it won't be packaged in a nice box (Cinemag will have the appropriate transformers for about half the price). These boxes are frequently used and have been even in the old days. Good luck, -Tom
  9. Absolutely not . I believe it is a cable issue. This is not uncommon
  10. Yes, you will need four channels of amplification. My suggestion was to simply use what you have on hand or what you can either borrow, or pick up for cheap on Craigslist. My store room may look different than yours, Over the years I have accumulated quite a bit of gear that is now just laying around. I sometimes assume that others have my same bad habits. -Tom
  11. Honestly, you are going to have a full plate when the Jubilees arrive. Personally, I would concentrate on getting them set up in your room and adjusting & re-adjusting their locations and the the location of the seating area. The issue of amplifiers (within reason), will simply be "frosting on the cake" and not really a major concern. Get used to the Jubilee sound first and then go from there. Good luck, -Tom
  12. Well, you want an amp that does not have much background hiss or noise. I have been happy with the old Adcom GFA 5x5 amplifiers (535, 545, 555). They will be at least 3 decades old, that may or may not be a concern for you. They are on Craigslist all the time and selling at reasonable prices. Good luck, -Tom
  13. Well it looks like there is progress. This is not the first time someone has had problems going from balanced to unbalanced, although it is curious that that the "junk" coming through is at such a high frequency. I assume the cable is XLR at one end and RCA at the other (IOW, no additional connectors added to an otherwise three wire cable). This probably is not the problem, but have you measured whether the pin 1 and pin 3 on the XLR side side of the cable are electrically tied together ?
  14. Come on guys ... this is just a guessing game at this point. The OP needs to be more articulate by what he means by "whistling". Please be more specific, otherwise we are only guessing and any advice you get will be very suspect.
  15. At this point, one could say "Eureka", but that is such an obvious joke .....
  16. Styrofoam pellets are probably preferred - certainly safer
  17. You said the K-402's have cracks in them. Could you show us photos detailing these cracks?
  18. There are a number of things that don't add up here. 1) Crossovers seldom "just die" unless they were heavily abused. Connectors, come loose etc, but I would first make sure the the problem was the crossover - there are logical ways to do that. You or a friend will need to have an inexpensive volt meter at the very least. 2) there is really no such thing as a substandard crossover (I think you mean some sort of generic crossover. I am guessing). If that is the case, then of course they don't sound very good. 3) First make sure all the drivers are working and the signal is getting through. 4) use the "good crossover" and have a friend order replacement parts from Parts Express or Madison etc (resistors, capacitors, fuses). If there is an auto former on these (and I don't know if there is), I hope you still have that part since they are difficult to replace with the correct one. Any auto former or inductor should probably be okay. These may have one of the Klipsch protection circuits on it (they had a silly name IIRC). Those will not be necessary. 5) before you take anyone's advice on this (including my own). A) let us know specifically how you determined that the problem was the crossover and B) take a picture of the cabinet and several pictures of the crossover. Any advice without these two points of information is likely to misguided. Don't worry it can be fixed, -Tom
  19. Yes, I also got a deal on mine. They simply don't come up on the used market all that often
  20. Well you need to start with your requirements. Are you willing to use a pro amplifier that has DSP internally on the front end? Do you require a digital input for DSP? Are you putting the (analog) attenuation after the DAC from the DSP box (this means the not only the signal but any residual hiss / noise is also being attenuated)? How sensitive are you to a low price? Do you have any desire to use FIR filters and not just IIR filters? This is just a start.
  21. Just on a cautionary note. Do you think the 2050's that Klipsch buys (and perhaps modifies) are same quality as the ones that Parts Express buys? Do you think that Klipsch might require certain modifications on the 2050's when they buy them? Something to consider.
  22. Actually, there are many choices.
  23. Roy, I would hide. They may come and want to grind up your bones.
  24. I would give zero weight to the number posts that someone has. There is one guy on the forum that probably racks up 2000 posts in two weeks. Do the arithmetic, do you think those are thoughtful comments he is making?
×
×
  • Create New...