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Bossobass Dave

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Everything posted by Bossobass Dave

  1. Thanks for the link. I've read this and the auto EQ vs the "target FR" articles in the past. I compared (one of many that have changed with remodels and changes in hardware over the past 15 years of measuring in-room) my response at the LP to the results of the auto EQ article. 1) One guy preferred the low end bumped +15dB (IIRC). 2) IMO, 1dB/octave, which amounts to (+/-5dB) is tantamount to a flat response without EQ post smoothing, which I don't use. 3) My high end is bumped because I've lost a chunk of hearing capability up there, but I don't find a more rolled off high end objectionable. 4) I listen at significantly higher playback levels, which alters perception. Any test should use only program where the mix level is known and matched. 5) A noted caveat in the auto EQ article is: "Program material is a nuisance variable". 6) The results of all of Harman's studies leave out the fact that they reveal a simple conclusion; a) either the producers of the selected program source had seriously flawed monitoring hardware or b ) they really sucked at mix production. 7) Playback systems that roll off sharply below 50 Hz shouldn't even be a part of a listening session of any kind, IMO. 8) All of the hardware used is a Harman product. 9) Sine sweep FRM graphs are always the metric used. Reminds one of "listening tests" over the past century: Was Edison serious, or was he selling his invention? Note that some of the "listeners" have the blindfolds covering their ears!! Also note that they are all old guys whose hearing might be dubious. Acoustic Research conducted many "listening tests" comparing "Live vs Playback": WUT?? If I post the Ground Plane measurements results of the Raptor, someone please predict what will happen before the virtual ink is dried? This "test" cracks me up. It seems the principals got the wrong memo on which of the human senses were being tested? Preferences don't mean much and the industry should get that and move on. Nothing against any preferred curve, just that proclaiming one a "target" over others is just silly. Members are appreciated for their posting efforts, especially guys like SME who have interesting stuff to post. But, edicts such as "your method is BS because Harman said so" should expect some blowback.
  2. I responded to your thread based on your OP in which you declared that it's sad that any authority would suggest the best calibration from a recorded source playback system is a flat response. You declared it, right here and now, to be bullshit with no disclaimer. You support that absurd declaration by mentioning "numerous blind listening studies conducted by Harman" though you don't define numerous nor do you cite any of them. I've said about a thousand or more times; the equal loudness curves are built into all commercially available recorded material. I have been a participant in enough of those sessions and processes over the past half century, beginning at age 13YO, to assure you that no producer has ever mixed the content flat assuming that SME or anyone else will re-mix the product, post production, using a one size fits all calibration adjustment. For various reasons, that material may end up anywhere on the quality scale which exposes the flaw in such an approach. Think about it. A producer is deduced to have radically different hearing than some random collection of listeners to the point of requiring post production production to get the mix right. And, THAT conclusion isn't bullshit? For the record, I don't have any music program that requires a +5dB boost in the bass region to correct for a thin sound. That doesn't mean there is no such program, it just means that i don't keep poorly produced source in my collection. If one falls prey to Harman (or any other of the thousands of 'listening studies') conclusions and calibrates to some distorted bias, then every recording played back on that system will show that bias. This is proven on the production side. Mix on a system other than flat and get a result that has too much bass or too little bass, which is what happens in reality. The proper method is indeed to calibrate flat and "season to taste' after that on a disc-to-disc basis. What others preferred during a listening test positively changes in those test subjects over time with the evolution of hardware and software, room construction differences, age and preference adjustment. Why you or anyone would think that he/she should conform to such a metric is beyond me, but calling a flat calibration bullshit is just not the way to be taken seriously.
  3. Okey Dokey, we're in unrecoverable mode now... I've played electric bass for some 50 years now. Not sure if you're that confused or yanking my chain? I'm keenly aware of its range and possible harmonics that may or may not survive production methods. You can't write music without knowing the ranges of the instruments involved. Actual bass instruments have fundamentals in the bass range. Their harmonics are played back by satellites and are far easier to manipulate to taste. My basses are all 4 string and cover low E (41.2 Hz) to 2 octaves higher E on the G string (123.5). A 100 Hz crossover point takes the subwoofer to 200 Hz, where it is down -30dB with LR4 LPF. Keyboard and 5-7 string basses go lower. Synth can generate fundamental to single digits. Transients (an impulse is one) have content to DC, regardless of the fundamental, unless they are purposely filtered. I'm not aware of anyone who has successfully generated, played back and measured transients cleanly and accurately. If you intend to only discuss your front 3 satellites, that would be a useful disclaimer. Of course, this isn't the case according to what you've posted thus far, so not sure what the LPF @ 120 Hz comment is supposed to mean.. My close mic measurements have turned out to be more accurate that Ilkka's ground plane measurements of the same Tumult driver in slightly different Vb Josh chooses to measure ground plane because the battery of tests he uses that were devised by others requires it. My close mic showed a perfect 12 dB/octave roll off whereas Ilk's showed a 10dB/octave roll off (which appeared in nearly all of his GP measurements of an unfiltered sealed subwoofer as unexplained phenomena in our private conversations about the subject). The bottom line is that the close mic method can be extremely accurate and has been used my many noted engineers over the decades. I realize that both of your frequency response magnitude graphs are smoothed. The question remains.. do you think I would not hear that peak because it isn't comprised of only the anechoic response of the loudspeaker or that it's possible to distinguish that distortion by your brain separating the anechoic (direct radiated) sound from the latent release of the stored energy sound? If not, how does smoothing help with the dominant distortion in your system at the mic? And, let's just say that I don't believe a human can even acknowledge 10-20 ms of delay much less distinguish the first and second sounds. Curious to know if you've ever employed a processor with delay and increased the delay until it is audible to you? And, that sort of experiment is with only a single sound and repeat, but it might help prioritize. You can use any means of manipulating the FR at the primary listening position that you feel distinguishes itself from the multiple theories on the subject best to your logical thinking. The best smoothing method is that of treating the room to the degree of dead you prefer. I remember the avalanche of posts when Audyssey first hit the streets that exclaimed and extolled the religious experience of a difference once Audyssey was run. Thank goodness, like most theroies, the crowds have calmed down and the manufacturers have made improvements. None of that will help you with the subwoofer which dominates the distortion of the input signal at the PLP. That's why my focus is there and not with the short wave frequencies of the audible bandwidth.
  4. To be clear, my concern and comments are confined to the subwoofer (RB+LFE+10dB summed signal) and the crossover region of the subwoofer and the satellites. A few of us have discussed and explored windowing in years past. I was once told that I need to use 'X' window for better accuracy of measurement, for whatever 'scientific' reason, which I forget now. Smoothing can take you all the way to anechoic response, as in a close mic with 1/2 octave smoothing (which is always what I've used). Shown below id the no-smoothing vs 1/2 octave smoothing close mic of my subwoofer system: This (comparing the close mic with the seats mic versions) is basically what you're doing with smoothing, but with your own choice of compromise: My response graph was a result of the suggestion by AVS member <forgot his SN> that I have bad response measurements because i use the wrong window. I used my usual window and then used the one he suggested. That result also has the smoothed close mic version laid over it. Then there are your graphs, smoothed and windowed, with scale normalized. Of course, I do not "hear" the 6 Hz resonance exhibited by my floor system, but I think it a bit absurd to suggest its influence should be noted by the close mic response or any in-between resulting FR due to smoothing and/or window views. Curious; are you suggesting that the peak your 1st FR shows at 110 Hz isn't what I would hear at the mic position?
  5. Your 3-5dB boosted sub sounds hot because it is. FR is never useless.
  6. No, I'm not aware of a single production disc that includes the mix desk FR, but some do include the mix playback level, which goes to the influence of equal loudness curves. I'm aware that some mixers try their product through different systems (most don't do that as a mix tool), but they rarely adjust the final mix for those results, in my recording studio experiences. And, the mastering stage is where the final mix is actually done, where none I've ever known left their seat during the mastering process. The next time you're involved in a studio, run the FR measurement yourself and note the playback level for your own reference. Like I said many years back, when the actual bass player is sitting in your sweet spot listening to a recording he played the bass on (something I did years back) and turns to you and says "THAT'S what I'm talkin' about!", how the hell do you argue with that? I could have told him that I prefer the bass bumped +10dB and I certainly have the right to do that in private listening experiences but that wouldn't have any relevance to how he told me it should sound when played back. That experience and listening to recordings on which I was the bass player opened my eyes. When you match the FR used to mix and the playback level, the result is very accurate, other parts of the discussion notwithstanding.
  7. My opinion is that every recording should come with a FR taken at the mix desk with mix level noted. Rooms are the largest variable and should be treated accordingly. Ham fisted use of parametric EQ has been the bane of audio playback. Studying the distortion preferences of the general public has nothing to do with proper calibration. Relying on Harmon is akin to asking Pfizer if drugs are good for your health. I read a Harmon study years back and saw this FRM graph. And when I normalized the graph to what we're used to studying... the house curve-looking graph is actually a flat response from a ported sub tuned to around 18 Hz with a typical 80 Hz LR4 LPF. The problem is that the sub used is covering 2 octaves of the 5-1/2 octave RB+LFE+10dB summed channel. The results are useless in my experience. Most people on this forum are enthusiastic about dBSPL. If you have a jazz quartet playing live in your room, you don't typically tell the upright bass player to move his instrument to a different position in the room, dampen the D string and pluck his strings a LOT harder.
  8. Define the terms. Cite the studies. How do you calibrate your subwoofers to the satellites?
  9. Exactly the problem, IMO. One man's "bloated" is another man's "thin". They are both meaningless terms to the reader. Mark mentioned decay earlier. As a matter of physics, generally speaking, the lower the frequency, the longer the decay, the more weight in the presentation. If a recording is brick wall filtered at 30 Hz, no amount of SW trim boost will add the weight that will be perceived when the same content is unfiltered. Subjective silliness aside (I'll use that word as no one has built a cross on which to hang Seaton for using it) "I like the filtered version better" "I like the unfiltered version better", Tastes Great", "Less Filling"... irrelevant. Mark then brings the differences in rooms into the mix. I've studied the FRM measurements of 15 forum members who can be relied upon to produce fairly accurate data. I've compared those to the known ground plane measurements of their subwoofers by Josh and Ilkka. I've found the room gain curve, which is derived from those differences and then averaged, to be very similar. FRM (frequency response magnitude) is predictable and has little to do with room size. I've argued this before in what the kids today call "contention", but the results are what they are, silliness notwithstanding. Rooms differ in how the boundaries are constructed and with what materials they are decorated. This has been known since the beginning of audio hardware and is discussed in detail in several books in my library, circa 1945-1960. I think you are correct (as Olive and others have suggested) that calibration begins with standardization on the production side. Absent that, FRM and level via the placement/phase method can be a practical one and an effective one.
  10. Of course not. Since the bandwidth includes quite a bit of infrasonic content, and boundary rigidity and transmission losses are not trivial, the reaction of the environment can completely change the presentation. I think the point of the OP is calibration method and the results therefrom. Back to Olive quote, with a different emphasis this time: The experiments I've looked into, since both of my sons are musicians who both record and mix their own audio creations and who both mix in the nearfield with a subwoofer, is along the lines of what Olive says in the quoted article. If my sons mix a snippet of sound, music or otherwise, and accompany that recording with a FR at their ears and recording level, it is notable that when you match that FR and level in the playback environment, the experience is far more accurate than the randomness of what you find in modern recordings. That would be the reference from which the "silliness" can feel free to roam, whether it be the spawn of any of the thousands of listening experiments done in the 20th century or the car sub enthusiasts-turned-home theater buffs.
  11. Hi Rowan, Can you post any data that helps explain your preference vs flat response? Trying to stay on topic here with calibration methods that explain preferences. For example, I've found that what most people think is a flat calibration is usually far from it.
  12. This post sums you up perfectly and is probably why you end up apologizing in PM regularly.
  13. Hacksaw Ridge: Digits vs Mic'd Doesn't sound thin (or any of the silly adjectives used to describe accurate playback in these forums) at all. The Oscar winning re-recording mixer saw to that. I'm pretty sure SME is talking about calibration methods here and not trying to argue that anarchy is the preferred course because otherwise sensibilities might be triggered. A flat response is the reference in-room. It's just common sense. What one does to the response after that is his or her choice... of course, but not relevant to calibration.
  14. Sorry, but there's no myth here. Surely, no thinking person would say that these two exact same subwoofers with different signal shaping upstream placed differently (from a GTG experience) would sound similar or accurate? I prefer Olive's opinions: The bolded part is by me as it sums my consistent opinion on the subject over the years in one sentence. Ever since the invention of bass and treble "controls" the distortion of recorded source through playback devices was off to the races. That grotesque distortion (typically +10dB <100 Hz and many times up to +20dB manipulation of the signal) has become indelibly etched into generations of brains. The nearly unanimous misapplication by enthusiasts (and many so-called professionals) of the Equal Loudness Curves has served to justify this learned preference for distortion. The point here is that subjective preference is irrelevant. Utterly and completely irrelevant. Unless, of course, you're using it to sell audio hardware or to justify your systems lack of accurate playback capability. Who here can explain what the sound effects in Hacksaw Ridge should sound like or review a systems calibration as to the accurate playback of those effects by employing subjective listening preference as the measurement tool? Flat level calibration and response magnitude, through placement and phase/trim adjustments is the best method to approach accuracy. Preference-led manipulation thereafter is generally unlistenably distorted, although enjoyed, celebrated and defended regularly in these forums.
  15. Yes, I've seen differences in a DVD vs the BluRay version and posted the graphs. Master & Commander comes to mind, but the BR came out years after the DVD. The GOE rental was a BR so the question here is whether or not the BR rental has a different mix than the purchased BR. They shouldn't be different other than possibly the level. Does anyone have the peak hold PVA graph of the rental BR to compare with your graph?
  16. If you're talking about Deadpool, no way. It's as blue as R rating allows. Lots of gore and language, IMO.
  17. No sarcasm, just curious because if the rental is that different from the purchase, it will be the first time it's happened in my experience. The rental, of course, has the lossless soundtrack and it certainly does not have the content shown in your PVA peak hold. If the rental can't be counted on to have the same content bandwidth, that's a problem because having to buy the disc to see what's on the soundtrack is unacceptable.
  18. I couldn't get on this site the last couple of days so, after screening Deadpool, I posted the caps in Adam's Raptor thread @ avs: http://www.avsforum.com/forum/113-subwoofers-bass-transducers/1664809-bossobass-raptor-system-3-a-9.html I just did a comparo animation of the mac daddy scene, mic'd full range @ the LP vs digits off the Oppo BD105 SW out with LPF @ 100 Hz. I was running the subs 3dB or so hot. I dug the movie and will be adding it to our collection tomorrow. The sound is just about perfect. Just enough ULF to add that bit of weight but not so much that it adds too much decay to the kick of the transients. And, the transients are what make this one demo-worthy. There's a billion or so of the best low end transients in memory. Just my opinion and a heads up. ^^^
  19. Yes, a rental. That and the possible use by Fat of an errant correction file are the only 2 possibilities, IMO.
  20. I found the level to be low and the brick wall is an octave higher. Not sure what method Fat is using to graph the soundtrack, but my sig chain is dead flat and I'm positive I'm not missing content to 10 Hz... ...as in Point Break: My copy of GOE was a rental. Might be the diff? Dunno, but I'm sure of the content I graphed with the disc I had here. It would have been MUCH nicer with content to 10 Hz, for sure. It was lame as I viewed it.
  21. GODS OF EGYPT lots of bass, but... PHIL-TURD At least an 8th order HPF @ 20 Hz throughout. Here's a snip of Chapter 15, which is indistinguishable from the bass in the entire movie (white means there is NOTHING there):
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