edwinr Posted August 31, 2004 Share Posted August 31, 2004 What is it about you Dean?. You bring out the angst in some people, yet in others you inspire awe and admiration! Quote Link to comment Share on other sites More sharing options...
radiob Posted August 31, 2004 Share Posted August 31, 2004 ---------------- On 8/30/2004 10:48:18 PM Dale W wrote: All the calibration tools in the world will never match the human ear . I use to be a " spec " junkie years ago untill i realized it did'nt mean jack **** cuz room sizes,acoustics and aux components are all in the chain . Just like the old dual carbs on my tunnel ram 454 LS-7 454 chevelle malibu , that girl always ran better when i adjusted the fuel air mixture and timing by ear and feel . If it sounds good then let her fly , sounds like crap then figure out why . ---------------- If you adjusted the timing and carb by feel, how do you know your running on the edge of detonation where your 454 will make the most power with the octane # of fuel you have? Also I have found that the best way to adjust your jetting on your carb is by running at WOT at peak RPM in high gear killing the ignition at the same time you let the throttle blades slam shut, get it stopped and pull the plugs to check for proper air fuel mixture and detonation by READING THEM. NO BODY THAT IS SERIOS ABOUT PERFORMANCE TUNES BY EAR and FEEL< NOT EAVEN AUSIN COIL> BY the way, what do you have for heads, compression ratio,cam and intake in the 454? Quote Link to comment Share on other sites More sharing options...
edwinr Posted August 31, 2004 Share Posted August 31, 2004 Hmmmm. I should try that trick with my Klipschorns. Now where is that spark plug wrench? Quote Link to comment Share on other sites More sharing options...
sheltie dave Posted August 31, 2004 Share Posted August 31, 2004 A good engineering rule of thumb for testing equipment is anything that costs a factor of 10 under what you are testing and less than $200 is a POS for results. The Rat Shack meter costs less than one of your new crossovers, Dean, so don't even think of judging performance unless you have a good 10 grand spec mike and about that again in an RTA! Good speakers deserve good test equipment. Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted August 31, 2004 Share Posted August 31, 2004 Dean buy a used Audio Control SA-3050 or SA-3051 RTA it is a much more effective tool than the Cheapo Rat Shack meter at analyzing room acoustics. They can provide a graph and SPL levels for the frequencies. I used to use my DBX 14/10 to RTA my room but I have since parted with just about all my processors and have stepped down to a single DBX 3-Band Dynamic Range Controller now just for my Sat Dish listening. Everything else is played back with no tone enhancement at all. Quote Link to comment Share on other sites More sharing options...
Deang Posted August 31, 2004 Author Share Posted August 31, 2004 Thanks for the input guys. Really though, I did the "test" primarily to see what the bass looked like. I figured if the structure wasn't rigid enough, there would be some loss. Trey had mentioned in another thread that when Klipsch had tried just using plywood, and taking it to the edge of the front baffle -- that things rolled of really fast after 100Hz. My ears were telling me it sounded good, but I wanted some validation. The HF results just caught me off gaurd. "Are you revoicing the speakers? Just what are the improvements intended? How can you be sure that different, "better" parts are not going against the intention of a designer who intended certain parts to work together in a certain way, a synergy?" This is an important question, but I don't have time to get into it right now. I'll come back later and address it when I have more time. For now, I'll just say I see it more like cleaning a dirty window. Quote Link to comment Share on other sites More sharing options...
artto Posted August 31, 2004 Share Posted August 31, 2004 Fine example of why I've said the Radio Shack SPL meter should NOT be used for any kind of serious room/speaker frequency response measurements. IT'S NOT "FLAT", IT'S CERTAINLY NOT EXTENDED OVER THE FULL AUDIO BANDWIDTH, AND IT'S NOT CALIBRATED! There's probably as much, if not more, variance in the microphone's response as there is in the speaker itself. The problem is you don't know where those frequencies coincide, so you don't know if the combination of the two are adding to, or subtracting from the measured results. Quote Link to comment Share on other sites More sharing options...
Dale W Posted August 31, 2004 Share Posted August 31, 2004 Radiob: Dude i'm talking " 20 YEARS AGO " when i was into racing and speed , we never had all the fancy electronics that are used today. Sorry if you misunderstood the point of my post , the meaning was more fine tuning then initial set up as in reference to dean playing with the khorns. He's tuning and tweaking , thats also what i did by ear and feel rather then by intsturment, hard to hook up a scope at the track . It's not like we had a tech 1 or tech 2 to tap a snap-shot of throttle postions relationship to gear selection in relationship to wheel speed. Nothing back then was electronic except the HEI if you were so inclined to go in that ignition direction . I've been a mechanic at the same chevrolet dealership for 23 years , believe me when i say i've built and raced everything that can burn fuel so if your atempting to make me sound or feel stupid in front of the other forum members by makeing silly references then the real jokes on you . Quote Link to comment Share on other sites More sharing options...
artto Posted August 31, 2004 Share Posted August 31, 2004 ---------------- On 8/30/2004 7:58:04 PM DeanG wrote: Bob, I've never heard that before. My meter is a couple of years old, and the manual doesn't say anything about that, does yours? Below are some well known calibration curves for the meter. My understanding is that the meter can be used and trusted for the most part as long as the corrections are made. ---------------- Dean, wrong. This is another part of the problem. Those "calibration" curves are good ONLY for that particular SPL meter that the person tested! It's NOT valid for ALL Radio Shack SPL meters. Being calibrated means that the YOUR specific microphone has been tested, and a calibration curve produced for it. This is a rather cheap product. It is not going to give you the kind of known response that a $1000+ B&K or Neuman or Schoeps CALIBRATED mic will provide. Quote Link to comment Share on other sites More sharing options...
ZAKO Posted August 31, 2004 Share Posted August 31, 2004 DEAN.....Your going to have to spend a couple thousand for a good calabrated mic. And twenty thousand with RTA. Dont expect a ratshack for 50 bucks to give you anything but below average readings. Its not even close to accurate callibration at all frequencies. Quote Link to comment Share on other sites More sharing options...
formica Posted August 31, 2004 Share Posted August 31, 2004 You may want to consider the IBF-EMM8 Electret Measurement Microphone available from ETF with a mic preamp for 250$. Although it won't replace a Bruel&Kjaer, it is a bargain for a tweaker as it comes with a calibration file. Combine that with a RTA software (like ETF5.x) that allows you to measure sweeps and adjust gate times... and you'll get a better idea of how your mods are performing. It may not be laboratory grade equipment... but it'll produce pretty good data which will actually reflect what you are trying to measure. Later... Rob PS: As a starter, you may download a trial version and use it with your RATShack meter to measure low frequency room responses. You'll see what it can do. Quote Link to comment Share on other sites More sharing options...
sunnysal Posted August 31, 2004 Share Posted August 31, 2004 dean, fwiw you can get an earthworks M30 mike for less than $500 street, it is an excellent mike for this type of use. dbx has the RTA-M mike for $150 which is quite acceptable as well...used RTA are available quite often on ebay for less than $500. regards, tony Quote Link to comment Share on other sites More sharing options...
Mark Hardy Posted August 31, 2004 Share Posted August 31, 2004 Old Colony Sound Labs has or had a fairly inexpensive calibrated electret microphone for measurements like this. I just perused their products at www.audioxpress.com but didn't see it. Perhaps no longer available? Come to think of it, anyone interested in speaker design or performance would likely enjoy audioXpress magazine, if you're not familiar with it... :-) Quote Link to comment Share on other sites More sharing options...
scriven Posted August 31, 2004 Share Posted August 31, 2004 Mark, I don't think this is what you were referring to but it does look like it has a calibrated mike. http://www.audioxpress.com/bksprods/kits/kc-cliom.htm Quote Link to comment Share on other sites More sharing options...
Marvel Posted August 31, 2004 Share Posted August 31, 2004 We have a Rane RTA where I work, the newer one can be found below: http://www.rane.com/ra30.html You can get this for under $500, and it may be all most would ever need. Works great for setting up PA systems for sure. Marvel Quote Link to comment Share on other sites More sharing options...
TBrennan Posted August 31, 2004 Share Posted August 31, 2004 Mark---That Clio Lite is just the kind of thing Dean needs. One of the guys who was in our horn club used a program he found online to test speakers. The program was free but one did need a good, calibrated mic. This young fella was THE sharpest DIY horny I ever met and someday will be up there with Bruce Edgar and Tom Danley as a modern horn guru, since leaving Purdue he landed a job in Kentucky with Eminence. Quote Link to comment Share on other sites More sharing options...
J M O N Posted August 31, 2004 Share Posted August 31, 2004 ---------------- On 8/31/2004 9:28:58 AM artto wrote: ... Those "calibration" curves are good ONLY for that particular SPL meter that the person tested! It's NOT valid for ALL Radio Shack SPL meters... ---------------- Not to mention that this calibration curve is only good for the room it was calibrated in. Quote Link to comment Share on other sites More sharing options...
Deang Posted September 1, 2004 Author Share Posted September 1, 2004 I forgot about Tom's question today. "Are you revoicing the speakers? Just what are the improvements intended? How can you be sure that different, "better" parts are not going against the intention of a designer who intended certain parts to work together in a certain way, a synergy?" I think Trey Cannon is borrowing Tom's moniker. I was talking to Al last month and this subject came up. I don't remember exactly how it came up, or the context it came up in, but I think Al said something to the effect of "improving the voice" of the speaker. I told him I didn't believe I was changing the voicing, which to me is the sonic signature or character of the speaker. Al asked if what I did changed the way the speaker sounded, and I had to concede that it did. "Well then, you are changing the voicing." Apparently, I didn't have a proper understanding of what "voicing" meant. I still have trouble here, and think it overstates the effect. I believe a change to circuit changes the "voice". Leo's resistor mod for the RF-7 that I use is an example of this. However, I don't think anyone who heard the results of the upgraded parts and resistor mod on Jesse's RF-7s in Arkansas would say that I "changed" the RF-7 into something that didn't sound like an RF-7 anymore. Even with the change to the circuit, there was no question as to what we were all listening too. Let me ask this: When we change out an amplifer, or preamp, or anything -- does it "change" the sound of the speaker? I say yes, and sometimes dramatically. Should we argue that we should all use what Klipsch used to "voice" the speaker? I mean, if we aren't, then we certainly aren't hearing what they heard when they "voiced" them. Do "better" parts -- those made with known superior materials and construction methods "improve" the performance and sound of other things we use in our systems? In everything except our speakers? With the exception of the resistor mod in the RF-7, all the parts I use are built with the best materials, the best construction methods for the part type -- and WELL within stock tolerances. I replace good plastic caps with excellent plastic caps, and worn out PIO motor runs with the best PIOs available for crossover applications. The "intended" improvements are found in listening: Increased dynamics, better imaging, cleaner, richer, smoother, and just plain more musical. Quote Link to comment Share on other sites More sharing options...
edwinr Posted September 1, 2004 Share Posted September 1, 2004 ...and Dean, don't we change the 'voice' of our speakers everytime we move them from room to room, or home to home? PWK, somewhere had to, as Klipsch does now, choose a neutral voice as far as possible so that our Klispchorns or whatever Klipsch product takes your fancy, can work in as many rooms as possible. Surely it is then permissible to tweak if necessary? Quote Link to comment Share on other sites More sharing options...
maxg Posted September 1, 2004 Share Posted September 1, 2004 "Let me ask this: When we change out an amplifer, or preamp, or anything -- does it "change" the sound of the speaker? I say yes, and sometimes dramatically. Should we argue that we should all use what Klipsch used to "voice" the speaker? I mean, if we aren't, then we certainly aren't hearing what they heard when they "voiced" them. " I don't think that that is quite the point. Yes - supporting equipment will effect the way any speaker sounds but it should do so in a consistent manner for the given speaker in a given application. In other words having a front end set-up all ready and dropping in a pair of RF7's should sound identical to the same setup with another pair of RF7's. If not then there are some worring manufacturing issues to address. On the other hand - replacing the standard set of RF7's (in any system) with your tweaked Xover units should sound different - if not what are people paying for? Therefore - you are changing the voicing of the speaker. If potential purchasors prefer the voicing of your version then this is a good thing for both you and them. If not - maybe time to go off and build and amp or something.... Quote Link to comment Share on other sites More sharing options...
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