Jump to content

radiogram

Regulars
  • Posts

    106
  • Joined

  • Last visited

Everything posted by radiogram

  1. Ok. It WORKS NOW!!!! Turns out the WT3 contradictory to claim of Windows 7 Support, is not working under Windows 7. I borrowed an Old XP Laptop and when I tried it on that it seems to work well!!! It caliberated well including test leads and I did some sanity tests with known resistors and inductors and it measures pretty close with good consistency across many sets of runs. I will be making a separate post with measurements on my drivers.
  2. I have had such bad luck with the WT3 Woofer tester. My first one was defective and parts Xpress sent me a replacement. Again the replacement does not work properly. When I short the leads and do Test Lead Caliberation it says resistance is greater than 1 Ohm!!! just like the first unit did. When I measure a known 8 Ohm resistor it comes up with Re=40 Ohms!!! On Bob Crites Woofer it measures Re as 1 Ohm (BEC Woofer Re is around 3.6 Ohms). I am so disappointed with the WT3 and I do not know even if I get another replacement I will trust it. Lee - Have any of you used it with Windows 7? Or anyone used WT3 with W7 with good results? Thanks
  3. Al: Just realized that that AP12 woofer section is an even (second) order one. I guess had it been an odd order one you could have subtracted the Le from the last inductor if its value were >= Le, but cannot in this case even order case.
  4. Al: Subsequent to your finding of the actual complex K33 woofer impedence to be about 6+1j, you have mentioned that you actually subtract the 1mH Le from the required inductor value for the woofer section (instead of using a zobel) and thus you also now recommend 1.3mH for the universals instead of 2.3mH. However, when I downloaded your AP12 desing form your website, the inductor values shown for various Xover frequencies do not seem to have subtracted out the woofer Le. Could you please clarify this? Thanks
  5. I am considering experimenting with the JBL 2426 Driver for my cornscala (I find the Atlas PD-5VH/K400 Combo very dull sounding and closed in with dominating midrange and as though the upper midrange were muted out). Looking at the published plot of JBL 2426 on a 2370 Horn that is attached here, it looks like I can even use it as 2-way without tweeter. While it extends nicely to 18KHz, the response between 5.5KHz - 18KHz is shelved down by about 3dB. This means the range between 900Hz-5Khz needs to be equalized down for flat response. Any ideas on how to implement this in a passive crossver? Also, is this difference in output between the feq bands change with a different horn? Al, have you run curves on your JBL 2426 on your trachorn? Thanks JBL_2426.pdf JBL_2426.pdf
  6. Djk - Thanks. Now this is interesting - 1W SPL = 96.78 dB; 2.83V SPL = 100.5. The only value of R being nominal impedence for which 2.83V would yield an increase of 3.72dB compared to 1Watt is R=3.4 Ohms, which is actually same as the Re. However, ALK has actually measured the K33's nominal impedence to be around 6 Ohms. If we use 6 Ohms, then @ 2.83 V the SPL will be higher by 1.25 dB compared with 1 Watt. Now, I am confused.
  7. 1. Searching the forum for K33 sensitivity, I find a wide range from 92.5dB to 98.5dB being mentioned. What is the actual sensitivity spec of the K33 Woofer? 2. As per Klipsch Cornwall II brochure, the speaker's overall sensitivty is sepcified at 101dB @ 1w/m. How did the sensitivity increase to 101dB when the K33's sensitivity is only in the 90's? Does cabinet the loading increase it?
  8. Al: In your zobel network recommendation you had mentioned to use non polarized electrolytic capacitor. Why does it have to be electrolytic and not say polypropelene? Similarly in woofer bypass caps or a N order T section filter to woofer, does it necessarily have to be electrolytic? Thanks
  9. I do not have the equipment to do proper A/B compariosn. But in any case My listeing is not just the woofer, it is integrtaed as a whole. Anyway, the main point here is if adding 80dB or 60dB to 90dB results in mathematically to only 90dB, what is is the advantage of building complex higher order network from a freq response stand point?
  10. The way the dB output of two drivers sum by math, does not seem to correlate with listening when using higher slope networks Vs lower order in terms of tonality. Of course, there are other advantages of higher order networks that consequent to reduced region of overlap lead to reduced combing effects and such. But for this thread I am confining the scope to ONLY SPL Vs Freq Response, since that primarily dictates perceived tonal balance. For example, Let us take the following hypothetical example for simplicity: - A woofer with a sensitivity of 90dB with a flat bandwidth of say 20-1000Hz. - A midrange driver with a sensitivity of 90dB with a flat bandwidth of say 300-5000Hz. - The midrange has a first order high pass circuit with a crossover (-3dB) freq of say 700Hz which is well within the drivers’ inherent passband. 1. Let us say we first implement some first order network for the woofer and let us say in doing so the output of the woofer is about 84dB (-6dB down) at say 1000Hz. 2. Let us take another case where we implement a higher order low pass such that the woofer’s output at 1000Hz is say 80dB (-10dB down). 3. Let us take another case where we implement a even higher order low pass such that the woofer’s output at 1000Hz is say 70dB (-20dB down). 4. Let us take another case of extreme slope, where we implement a higher order low pass such that the woofer’s output is say 40dB (-50dB down) Now let us sum the total spl in both cases: 1. In case 1, the total output is 84dB + 90dB = 90.97 2. In case 2, the total output is 80dB + 90dB = 90.41 3. In case 3, the total output is 70dB + 90dB = 90.04 4. In case 4, the total output is 40dB + 90dB = 90 According to the above, whether the woofer is at 10db, 40dB, or 70dB or 80dB the total spl is always 90dB, implying that a higher order network has no effect on ultimate spl due to overlapping driver output. But, clearly I hear difference between a third order and 1st order in such a situation. Of Course, we have less of combing effect and such at the overlap region with higher order that contributes to listening differences. But I am, as I said confining to tonality issues alone that is primarily determined by SP Vs Freq and I do hear difference in tonality. Can anyone explain this?
  11. Robert: I agree with others that with a 1st order network moving from 500 to 600Hz is not worth it. Also, not to confuse you, but I spent a few hours at ALK's house last Sunday, and I was mightilyy impressed with the the JBL mid range driver + Al's trachorn, he uses in his modifed Belles. It had a certain palpability and naturanlness that was so good and that too I later realized that the source was FM Radio and not CD or Vinyl! I think he had the JBL 2426 but I do not exactly remember the model. You can check with Al on the JBL driver as well, since I am contemplating myself on replacing my K55/K400 combo (which I a personally do not find that great and actualy prefer the Herseys K53/K701 combo in comparison) with JBLs and Al's Trachorn myself. Just another flavor to think about. Whatever direction you go, good luck and have fun. Regards
  12. psg: Yes. I have Bob's Cornsxala Xover which does the same thing rollling off the highs of the squawker with a series inductor that suits the CT125 much better.
  13. I have a pair of CT125’s in excellent condition. I bought these for my Cornscala project but ended up with K77-F’s instead. This has been used very lightly at most 60-70Hrs. The only thing I would like to mention is that one of the tweeters, the terminals have a slight play (they can swing a bit if you push) due to my frequent connecting & disconnecting during evaluation. But the connection is secure and does not cause any issues whatsoever. I am asking $99 for the pair Plus Shipping. I will be in the US only between Sept 20 – Oct 8th and will be back in India. So if anyone is interested we need to conclude the sale before Sep 27th so that there will be enough time to ship and resolve issues if any before I leave (I do not foresee any, but just in case like bad UPS handling or such).
  14. Islander: Fair Enough. Happy listening. BTW: I am posting my CT125's for sale if case anyone is interested.
  15. Islander: I totally disagree. Just beacuse a tweeter is a physical Drop In has absolutely no bearing on how it matches with your existing speaker & network. Certainly subjectively one couls find it an improvement, but if subjectivity is the thing, then any one can drop in virtaully ANYTHING that physically fits can claim improvement. My post was based on objectivity not subjectivity. One could use an equalizer or a tube amp with high output impedence and find the altered response better. The point here is when we say Drop-In it has to have some objective basis and CANNOT be based on subjective impressions. One's subjective opinion is as good as another. No credible equipment manufacturer blindly builds things on subjective hearing including Klipsch. They may use it to tweak the end result but the foundation is still solid objectivity. Objectively the CT125 is a mismatch with first order networks that have squakers extending up to 6KHz. Just beacause one likes its overlapped sound cannot not in anyway make my analysis wrong.
  16. Dean: Thanks for the suggestion. I also read good things about HD600/650. The HD600 is very much in my radar even though it is a bit beyond my budget. Do you have any experience with Denon Headphones? I am sure you are right about this. While I never owned quality headphones, I have herad a few.
  17. Greg: I think what everybody is trying to say is that while ultimately we all listen and decide, there is a basis and foundation that precedes listening i.e. sound (no pun intended) principles of physics, acoustics, filter theories, electrical engineering etc. I certainly appreciate your passion with KHorns and sharing with people with your subjective experiences, of course you are not the only one, there are a tons of others who do so and not all of them may be anymore technically qualified than you are. However, any subjective analysis without precise understanding & adjustment and covering of all technical basics (at least as we know of today) could mislead one i.e. the evaluator himself, in deciding what is better or worse. Sure enough, if everything is based on technicality alone then no amplifier or speaker manufacturer would even bother having a listening evaluation or a listening team. They will simply apply theory, build, measure it and ship it out. But we all know that is not the case. They do listen. But in what sequence? They just do not start building arbitrarily by just listening and tweaking endlessly. They start with some technical fundamentals and theory. This is the BASIS. Listening is only next, to validate and tweak further. If this were not the case and ultimately only ears matter then I am sure these companies can make more profit by hiring anyone who can just tweak circuits by trial and error. But again they all have EEs, Physicists, etc in their R&D (I am not talking about mushrooming internet based audio compaies that just rebrand cookie cutter designs). Why should they bother when they can pay someone else a lot less to just listen and decide? After all they are business houses who sell to customers. PWK himself has a formal background in Physics and Engineering. Even Amar Bose who does not publish specs has a PHD from MIT! (one many people hate, but I do not). Anyway, all things we use in life, audio, cellphones, automobiles, microwaves, etc – they were not created by some accident by some non-technical person. They were all out of inventions from scientists, Mathematicians, physicists, Engineers, etc. The CD format we all listen to these days is nothing but an application of mathematicians (Fourier, Nyquist, etc). Sure if a common man looks at Fourier transform it is total gibberish and techno babble. But digital recording and digital telecommunications work only on this principle and not by some accident or tweaking. There is a good scientific reason why medform works for diabetics, why Tylenol helps headache and all these came out only from science and principles that are measurable. Should a diabetic just go by his gut feeling on how he feels or should he periodically check his glucose numbers? The point about do not bother me with anything technical but I want only what the ears say, IMO probably applies to people who are casual listeners and mostly do background or party listening. I have some friends that prefer their HT in a box to my Klipsch’es and even over a well regarded monitors I owned in the past (Proac Response 2). Of course their rationale was the same – I do not care about what technical explanation you give, my my ears like my HT in a box. That is their choice, they are entitled to it and is fine with me. But the point here is, when we are talking about people who own speakers like KHorns/B&Ws/Quads/ etc, these are a different sect of people who are a lot more discriminating (I am not of course including rich snobs who just own these only to show off just because they can afford it, without any real passion or understanding of audio – If one stuffs a radio shack into a audiophile suit with mega buck price tag they may buy it and be quite happy and proud). The tweeters you have tested themselves exhibit so much variation in not just sensitivity (and that too one that varies at different frequencies) but overall response characteristics, pass band band-width, roll characteristics, etc. Having a same network to judge all of them may not be fair to all of them and may bias you unfairly even if that is not your intent. The ideal thing would be to customize network for each driver separately with some common performance goals that again is within the limits of all the drivers and then compare them as not just tweeters but as driver-network pair. But this requires understanding what to measure, how to and needs precise caliberated instruments. And even when done so, need to be recommended as a tweeter cum specific network combination as a pair. So, the bottom line here is while we can all say ultimately we tend to judge by ears, the fact is that we will not even have that luxury to say so if not for science & measurements to begin with. Cheers
  18. Yes, they do and I also like Mick's drumming. This reminds me of the song "Dreams" and made me realize that I have not listened to FM in a long time. I am going to serach that CD down and play it on the Cornscala's I built recently. Cheers
  19. Lee: I understand your points. My dissatisfaction with many recordings actually extends beyond the CCR example. Even many modern CDs I have that were digitally mastered while they "sound" good there seem to be an aritificiality to it. Ironically even though the CCR album may not be up to the mark, it sounds relatively much less artificial than some modern digitial recordings. As I have mentioned in another post in this thread, the drum track on a test CD I have sounds pretty close to real. I am able to identify that drums with what I experienced last year up close in a small Italain resturant in Greenwich Village NY where a live Jazz band was playing sort of a spanish fusion Jazz, pure live unamplified (It was an awesome experience BTW). But I am unable to relate the drum and symbals in the same manner with many recordings I have, even modern ones. Maybe I am conditioned growing up listening to good old rock & roll that was just pure and simple - Drums, Lead guitar, Bass Guitar, maybe a keyboard and that's it (no other ecletronic crap) and perhaps this why I am finding them to be more natural than modern ones in spite of their limitations using analog equipment for mastering. And thanks for the pointer to RPG. Gram
  20. Shawn: I do agree with that. However, the reason I also brought up the recording was, for example I have a test CD that has a track that has only the drummer and no other instruments. This track in the same room and the same system, the drum and symbals sound very close (if not quite) to natural. If it was mostly the room this track must have also been influncenced as it does with other commercial ones. But many commercial ones I have, even modern digital masters, the drums and symbals do not sound stand out separate as much and they are somewhat burried as part of some many others. Now, this gives me a good excuse to buy a pair of good headphones that I have been putting off for a long time. Any suggestions under $300? Thanks
  21. Lee: I recently went to a party a few ago where they had a live band (of couse the eventual sound was still coming through amplifed electronics and JBL speakers). They were playing a lot of classic rock like CCR, Alman Brothers, etc. Never in my course of that session I had any thoughts about any audiophile jargons like midbass, upper bass tightness, etc. The only things I were remarking on were how the drum and symbals sound good and so the drummer must be good or the singer is OK but really cannot go high pitch like Fogerty, etc. I came back home and put on my CCR, etc CDs, that were played at the party. It did not sound the same. It did not sound bad but I was only reminded of lower mid congestion and all audiophilia jargon that never entered my mind in the party. I hear bass but not distinct drums, I hear symbals but something burried in the mix, soft and not metallic and live as it sounded. In fact this is the case with many of my CDs and even some Vinyls. Of course the Room has a LOT to do with it. But I somehow feel that it is not just the room and the recording has a lot to do with it. In that context I am surprised as to many people cite commercial recordings as a reference in evaluating speakers when they are mixed as per the Engineer's preference and based on what room and what monitors he used to equalize, when none of them match up with the system and environment under evaluation.
  22. This thread has made me realize that I myself is now confuded on how to match sentivity between different drivers (be it instrument or ears or whatever). A driver's sensitivity is not constant. Lets us say that Tweeter A has a an average sensitivity of 106dB in the 4-6KHz range and average sensitivity of 99dB in the 10-15KHz range (Somewhat like K77). Tweeter B has an avergae sensitivity of 103dB in the 4-6KHz range but has an average seneitivity of 101dB in the 10-15KHz range (somewhat like Beyma). Now what band will one use to match sensitivity? If I use 4-6KHz band to match up that means Tweeter A will be at 96dB in 10-15KHz range and Tweeter B will be at 101dB in the same range. Then Tweeter A will sound let us say lacking in air whatevr jargon that is. Alternativley if I use 10-15KHz band then Tweeter A will be +5dB more than Tweeter B in the 4-6KHz rnage and will subjectivley sound brighter or in your face or more detailed as one may choose to describe it or conversly Tweeter B may sound dull or more listenable or refined etc. So it may be important to specify what are the sensitvities in the whole pass band first and then explain the choice of what reference frequence or bandwidth that was used to match sensitivities. What do you guys think?
  23. I have been a Hersey owener and recently bought a pair of K77-F from Klipsch for my Cornscala project. It seesm to me tha the K77-F extends lower than the K77 in my Herseys (circa 1984) and they also seem to have relatively flatter balance and overall better sounding. Has anyone done any actual measurement plots? Thanks
×
×
  • Create New...