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Showing content with the highest reputation since 07/08/2018 in all areas

  1. 1 point
    Speaker tuning with radiation pattern, on-axis response, power response and then add in room acoustics - which will be more or less an unknown parameter for a speaker designer. This is difficult and complex, and has huge impact on perceived sound - in contrast to amplifiers, dac's, all the nonsense products. I also believe that this field has not yet been fully discovered, there is still more to learn and find out. Experiments focusing on how perception of sound relates to the technical parameters are key factors for improvement. Horn speakers sound different from trad-hifi partly due to fundamental differences in radiation pattern. It is impossible to make them sound equal, because tonal balance depends on what sound is being reproduced. If you tune for flat and equal steady-state, the transients will sound different because decay profiles are different.
  2. 1 point
    Yep, I am absolutely aware of these things. Almost no speaker sounds right with a ruler flat on-axis response. Of course, that doesn't mean that manufacturers are tweaking their speakers on the basis of actual power response measurements, which are difficult to do correctly. I'd bet that almost every speaker design gets tweaked at least once, based solely on subjective listening tests before being finalized. My guess is that most speakers start up with fairly flat on-axis responses as a baseline and then get tweaked from there There was a time when more speakers were designed specifically for flat power. As I understand it, there was a kind of rivalry between people who believed the flat on-axis was optimal and those who believed that flat power was best. JBL was a big proponent of the former. Allison was a big proponent of the latter. Allison did some remarkable work designing speakers for placement against walls and trying to optimize passive signal shaping to maintain nearly flat power under those conditions. I grew up listening to one of Allison''s designs, which I remember fondly. In the end, flat on-axis essentially won in listener preference experiments. However, flat power may be have lost in part because such speakers almost always had up-sloping first arrival responses, for the reasons you note above. Or maybe it's not about the up-sloping first arrival response but the *lack of slope in the power response*? Personally, I'm pretty certain first arrival is still very important. Otherwise, one would expect horns to sound rather dark compared to cone-and-dome speakers with the same on-axis FR, which is definitely not the case. In any case, I have no doubt in my mind at this point that power response counts for a lot.
  3. 1 point
    The real value of the hard work is probably in the comparisons. New tools for old data! The new site now allows up to graphs from 4 systems to be seen at once. A user can see from the left hand section list which graphs have comparable series (only certain graphs apply). In this screen shot we are looking at the FV25HP and overlaying 3 systems shown in the header while looking at the Max output. A user can toggle on or off other systems (up to 3, rather than just 1 like before). The comparing is also sticky so a user can copy the URL and reopen it anywhere and see the data again w/o re-queuing the overlaid systems. As we populate the data this tool will become the bread and butter of the website. Graphs like THD and compression are very rich in information too but are not appropriate for comparing outside of the system. That is more used as a tool to see how a particular system behaves with respect to voltage. A user can scroll through all of those graphs but they won't be overlaid with other THD graphs as the variables don't always make sense for comparison (voltage and db changes, etc, and the sheer number of series would be unwieldy)
  4. 1 point
    Good questions. Your first comment is why I stepped back from excessive amounts of EQ and trying for "perfect" graphs, even ones taken over large areas and averaged. They usually sound very bad despite looking great and allowing forum bragging rights. Notch type high "Q" equalization is especially bad to my ears usually.
  5. 1 point
    This is more or less correct. Each type has its pros and cons, and the end result depends on many other factors. It's possible to build a sealed sub that is sloppier sounding than a vented sub. A poorly designed horn or even a good horn that's used outside its ideal range can exhibit more noise and distortion than a better implemented sealed or ported sub. Among these, choice of driver is also a substantial factor. And last but definitely not least, the effects of room acoustics and placements on bass are substantial in small rooms. The relative benefits of sub horns are more apparent when used in large rooms and outdoors where greater output is needed and distortion is more audible. Indoors, room acoustic effects are much stronger. The room acoustics tend to provide low frequency boost, potentially reducing need for output down low and reducing audibility of distortion. On the other hand, small rooms benefit from multiple subs placed at different locations, and these benefits can extend to frequencies above the traditional sub range in a well-designed system. For this reason, I believe horns are less attractive for small rooms because of their (typically) large unit size and more limited upper end bandwidth. That doesn't mean that they aren't a good choice, but the justification is weaker than for large rooms and outdoor spaces. All speakers and subs have some baseline noise and distortion that are present even at low levels. However, it's a matter of debate how audible these things are. Some people claim to be able to hear a difference, but I do have my doubts. I find that *linear response* (i.e. frequency + phase response alone) including room effects and involving the full musical bandwidth has such a strong impact on perception that it's very hard to reliably judge the non-linear aspects (noise, distortion, and dynamic compression) of the sound. I will admit that I myself have had the impression of hearing cleaner sound from my subs as I have upgraded them, but given my experiences with linear response, I have to second guess myself. The exception to this may be in outdoor environments. As @Ricci can attest to, the lack of acoustic effects including room gain together with use of pure tone sine sweeps reveals a lot about the sound that may not be noticed inside a room with "normal" content. Please allow me to point out a few things. First and foremost, sub-bass is almost always accompanied by higher frequencies, which have a major impact on the perception of that sound. In fact, without higher frequencies, sub bass cannot start or stop. The transient response of sub bass has everything to do with higher frequencies. Try listening to the sub play with the amps to the mains turned off and note that it's not tight at all. So if you perceive a lack of "energy" in the 35-65 Hz range, it could be that you are perceiving poor transient response for notes whose fundamental fall in that range, which could involve not just those frequencies but also frequencies up to a few octaves above. Second, the vast majority of vocal content exists above the sub range. In principle, the fundamental frequency of the lowest bass vocalists reaches down to around 60 Hz, but even then, almost all the content involves higher frequencies. Most vocal recordings are high-pass filtered somewhere around 100 Hz or even higher. (A lot of mic pre-amps have a switch to engage such a filter.) With an XO of 60 Hz, very little vocal sound should be coming from the sub at all. None of this is to say that your mains are in any way the cause of the problem, though without quality anechoic measurements, it's hard to say for certain. Nevertheless, room effects are likely very strong in your case, especially being that you have concrete walls, and it is important to consider them in conjunction with the speakers and subs. Two kinds of room issues may be involved. First and most important are room resonances, which are peaks in the response at certain frequencies. For example, in the 35-65 Hz range, it is very likely that you have one or more strong room resonances. You probably have some above that range also. These can have a substantial adverse impact on the sound regardless of what the subs and speakers are capable of. Room resonances can be addressed by moving the sub or listener, by using additional subs in other locations, or by using EQ to attenuate them. Room measurement capability is very helpful to identifying problematic resonances and confirming their reduction after applying one or more solutions. The second potential room issue involves interference causing a suck-out, particularly from the wall behind your speakers. Being large horns, your speakers are much more resistant to this type of problem than most, but depending on their characteristics including their depth and distance from the wall, they may still exhibit a suck-out down low, for example in the 70-120 Hz range, which is responsible for a lot of bass power and loudness of frequencies an octave below and certainly could influence perception of the lower registers of some vocals. Unfortunately, the suck-out may be harder to fix. Moving the speakers will change the affected frequencies, and putting more distance between the speakers and wall will help overall. Adding fairly thick absorption on the wall behind the speakers (ideally 6" or more, depending on material) can also help quite a bit. In either case, measurement capability is key to identifying and correcting problems. It is indispensable. It can also help you improve the integration between the mains and subs. With all that said, it's probably still to your benefit to upgrade your SVS sub for those times you like to watch movies or turn music up higher than "65-80 dB". The key question is what suits you best, and that depends on a lot of things. I think getting a handle on what your room is doing is a good starting point, especially if you are tempted to get horns. If you find that you have a lot of room problems above the 60-65 Hz crossover, you might want a sub that can cleanly play higher. To your last point about your mains not being strained, by running full-range: Technically you are correct, at least in so far as you aren't pushing them to their limits. However even if not strained, the baseline distortion from frequencies below the 60-65 Hz limit of the horn will be greatly amplified by the horn. A high pass filter may still be desired here, especially for movies which can have some pretty hot low frequency content. The downside to using a high pass filter on the mains is that it may make integration with the sub more difficult.
  6. 1 point
    First post around here. *Yay* Rad, I think you can attribute both the rising response and the high sensitivity up top to directivity. Under sane and normal circumstances, the highest sensitivity you can reach in half space is 105-106db. Of course, in quarter space, you can add another 6 to that. The bigger the baffle is in relation to the wavelength, the more the source will be seeing a quarter space scenario. (Then ofc you might be able to see another db of sensitivity here or there, caused by diffraction off of the edges of the baffle.) This right here is a pretty neat little piece of software: http://www.tolvan.com/edge/help.htm It calculates the gain caused by the baffle. (It also does calculate what kind of a passive crossover you'd need to compensate for the baffle gain.) Toying around with that software(doubling the height of the cab to emulate a half space scenario), I find that the baffle adds about 1db at 30hz, rising to a 4,5db addition at 100hz. That should explain most of the phenomenon.
  7. 1 point
    Didn't you get the memo? Only drama films are allowed to have full-bandwidth bass soundtracks now.
  8. 1 point
    Nice. Did they let you see their equipment? I'd bet my cinema was cal-ed to near 82 dBC or maybe a tad lower as well. It was noticeably lower than I play stuff in my home these days, which is around 80 dBC, albeit with the influence of the much smaller room. With the thinness and slight 2 kHz push at the cinema though, I'm glad it wasn't played louder. Did they give you any info on how they did the cal? Was it X-curve all the way? Or did they let the low freqs rise a bit? Assuming the cinema I went to did a by-the-book X-curve cal, I'd guess that the dub-stage was on the dry side and didn't appreciably build-up room energy until below 200 Hz or so. Or else, they didn't do much EQ above there for other reasons. I think a lot of newer dub-stage / mix spaces are getting thicker absorption than in the past. A striking example of this is the "Game of Thrones" TV series. I believe their studios follow ATSC recommendations and calibrate magnitude-smoothed or power response to a flatish curve, which suppresses the bass compared to an anechoic flat system optimized for music. To correct for the bass boost that they are likely adding, I use with a low frequency shelf somewhere. For seasons 1-4, my shelf was centered around 265 Hz or so, IIRC. Results were a bit inconsistent from episode to episode suggesting that they were either working between multiple rooms or were addressing the low end deficiency in different ways each time. Then for season 5, they started doing Atmos mixes, which were almost certainly done in a new purpose-built studio with more low frequency absorption. The 265 Hz shelf sounded all wrong, and I had to move the shelf down to 225 Hz or so to get all the dialog to sound balanced again. I'm sorry to hear about your terrible LieMAX experience. I'm going to take a wild guess as to what may have gone wrong. AFAICT, Audyssey tech fits magnitude-smoothed response to a curve rather than power response, which is used for the X-curve. I've noticed that magnitude-smoothing, even at high resolution, actually omi a lot of tail-end reverb energy in room measurements. I believe the error is actually greater for higher frequencies because of the frequency-varying time-localizing effect of the smoothing kernel. E.g., 1/48th octave at 10 kHz is a lot more time local than 1/48th octave at 500 Hz. So as a consequence, the high frequencies may appear lower in a magnitude-smoothed measurement than a power response measurement, and XT32 may be boosting them too much. Even just a dB or two hot up top is a recipe for some nasty overly bright sound. You'd think that the people agreeing to license the tech would bother to listen to the result and decide that there's something wrong if it's painfully loud at "normal" playback level. But that's not how technology works these days.
  9. 1 point
    We gotta new record: http://www.avsforum.com/forum/113-subwoofers-bass-transducers/2763785-ultimate-list-bass-movies-w-frequency-charts-85.html#post55059146 Would you look at that beaut! 5 star extension right there.
  10. 1 point
    Had not got T5 yet on video but will eventually. People love to poop on Michael Bay and T5 has serious issues but in a hobby for A/V..... T5 brings it. Interested in the Atmos track and if it is (better be) a remarkable improvement from T4's barely-Atmos track. And yes... let's bring back the days when 20hz was cool cuz it still is, imho.
  11. 1 point
    Just wanted to add that I did like the movie and my points were mainly nitpicking. The only real issue I had was that the big apocalyptic event the movie was building towards got abandoned in the last twenty minutes for a much smaller ending that was fine on it's own but felt out of place.
  12. 1 point
    The better my system gets, the less clipping bothers me. I think clipping tends to bring out the worst in any speaker it encounters. I actually enjoyed Thor quite a bit cranked up way higher than I would have imagined liking it before. (BEQ helped too.) I'd still prefer that the tracks were cleaner though.
  13. 1 point
    BEQ? Are you crazy? I'm not sure I'll be able to play back a BEQed version at my typical reference level. Look at that near-DC peak that's already pushing up to -20 dBFS. Edit: I guess that's what Crowson's are for. I am starting to think about getting those some day.
  14. 1 point
    It's actually better 2nd time around since you actually can figure out what's going on The overall atmos sound is amazing too
  15. 1 point
    I liked it better. Even James Cameron likes it which is surprising considering he crapped on the last 2. http://www.cinemablend.com/new/James-Cameron-Watched-Terminator-Genisys-Here-His-Review-71898.html They copied a couple of scenes from the first one note for note which was cool to see.
  16. 1 point
    ^^^ Never thought I'd be going to buy that movie...
  17. 1 point
  18. 1 point