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Showing content with the highest reputation since 07/11/2018 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
    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.
  4. 1 point
    I may have been overly paranoid, and I don't think I had the visual output indication (Motu 16A) that I do now. However, movies rarely have continuous, droning, high SPL sounds that are sustained for *a few minutes*, especially going to the surrounds. (The sub range is a different story.) Also, there's a big difference between playing very hot content for a few seconds vs. a few minutes. If you look at the average level for surrounds (not including sub bass) over one minute intervals across an entire soundtrack, I doubt you'll ever see anything higher than 90 dB per speaker, and I doubt you'll even see higher than 80 dB per speaker except in climatic scenes where the score is playing very loud. With that said, yeah I do want/need better surrounds soon bit more for instantaneous output capability than for long-term output capability. My current speakers are rated at 92 dB/2.83V/2pi/1m, but I'm fairly sure I'm clipping them from time to time with a ~300W/channel amp. (I can now watch the peak / RMS level of the signals going to them.) It's only on instantaneous peaks, and I don't hear any obvious distortion. Part of the problem is that they experience substantial boundary interference in the low mids, being that they are installed near a wall-ceiling corner. If I don't correct for this, they sound very thin and impart their thinness to the rest of the sound-stage when playing multichannel content including movie scores. With my latest optimization methods, I am able to correct this problem very precisely, but the correction does involve a lot of EQ boost. The end result is well worth it, despite potential for occasional clipping. For 99.9% of the time, the system sounds way better than it would without it. Still, I'd like to have a proper amount of headroom. FWIW, I'm pretty sure a lot of other systems have similar problems, and they most certainly apply to overhead speakers as well as surrounds. It has definitely affected my perspective on how to design multichannel systems. Surrounds and overheads are almost always placed in or near walls and/or ceilings. Where flush-mounting against a large, rigid surface is possible, there is less likelihood of a problem. However, for various reasons, this is often not possible. For example: It may not be possible or desirable to cut holes in the wall or ceiling. The room design may not allow a large rigid surface at the chosen placement location. It may not be possible to aim a speaker to achieve audience coverage goals when flush-mounted. For these and probably other reasons, surrounds and overheads are installed on or near the wall rather than in the wall perhaps in the vast majority of cases. With such placement, the sound of the speakers will be degraded without correction. The required correction requires a lot of EQ boost, usually to counter-act suck-outs in the low mids. At the same time, the nearby boundaries will usually interfere constructively in the bass range. As such when EQ/room correction DSP is intended to be used to achieve good performance, a good surround/ceiling speaker should have as high a sensitivity as possible. Excursion is not as important because most of the boost will be applied where excursion is low to begin with. Unfortunately, this limits the options considerably. Typical consumer surround speakers use small, medium sensitivity drivers and a ported enclosure to get the bass extension. These are seriously deficient in the crucial low-mid area. OTOH, small, high sensitivity drivers tend to lack too much in excursion and power handling. The implication is that good surrounds need bigger drivers, albeit light-weight pro-style drivers that have high sensitivity and modest excursion capability at the expense of bass extension. I had been planning on building new surrounds with 2 x 6.5" AE drivers and an SEOS horn, but I have other ideas now. In the long term, I want to build fully digital-driven arrays, but I have a lot of learning to do before I can do those. In the short term, I'm leaning toward a pro-style coaxial. I've seen some glowing recommendations for a few particular co-axials, for example from Radian. Unfortunately, most of the coaxials I've looked at, even the pro-style ones, appear to be designed to have significant bass extension I don't need at the cost of sensitivity. Most of the Radian coaxials just aren't as sensitive as I'd like, even at 12". IIRC, I saw one I liked from B&C that had a fairly shallow mounting depth and a woofer with a super strong Nd motor, providing like ~98-99 dB/1W in a 10". That's what I'm talking about! I think they also published polar response measurement data, which is almost unheard of in the industry. Once I have some expendable income again, I'll probably move on something.
  5. 1 point
    I have not posted here in a while. So this is where all the old guys all hang. Old as in long time posters. Scott, good to see you still around.
  6. 1 point
    Mr Allen at HPS4000 has been echoing your sentiments for some time: http://www.hps4000.com/pages/articles_page_.html Even though he considers <27Hz not part of the audible spectrum (he is not wrong depending on frame of reference, hence his choice on subwoofer low corner), he has some solid ideas in those articles, and addresses many of the things we complain about here. JSS
  7. 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.
  8. 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.
  9. 1 point
    Didn't you get the memo? Only drama films are allowed to have full-bandwidth bass soundtracks now.
  10. 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.
  11. 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.
  12. 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.
  13. 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.
  14. 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.
  15. 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.
  16. 1 point
    Big Hero 6 BEQ Solution: Pre-Post: LFE Correction: Gain: -7dB Low Shelf 16Hz, Slope of 1, +6dB (6 filters for a total boost of 36dB) LCRS Correction: Gain: -7dB Low Shelf 22Hz, Slope 1.5, +4.75dB (2 filters for total boost of 9.5dB) Low Shelf 23Hz, Slope 1.5, +4.75dB (2 filters for total boost of 9.5dB) Low Shelf 24Hz, Slope 1.5, +4.75dB (2 filters for total boost of 9.5dB) Low Shelf 44Hz, Slope 0.5, +0.75dB Low Shelf 46Hz, Slope 0.5, +0.75dB Low Shelf 48Hz, Slope 0.5, +0.75dB The film gains significant weight to large effects, and while improved significantly, is not a whole new experience, but what I believe to be an enhanced way to see the film. JSS
  17. 1 point
    Thanks! Any improvement is welcome. IMO, the soundtrack was excellent to begin with except for the lack of extension.
  18. 1 point
    The filters are for each channel individually, LFE means LFE channel before adding any rerouted bass from other channels. So, for JRiver you should implement filters for each of the LCR+surround+LFE channels according to the description given for the film. When LFE and bass from LCR+surround is routed to the sub output, you can apply filters to the sub output if you don't have access to the individual signals. It is not the same, but should give good results in many cases. Use filters specified for LFE channel. A good bass system has a dsp able to do this filtering. The multiple filters with smaller gain vs one filter with huge gain is to avoid too much overshoot due to the q, the response is not the same.
  19. 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
  20. 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.
  21. 1 point
    ^^^ Never thought I'd be going to buy that movie...
  22. 1 point
  23. 1 point
  24. 1 point
    Hi Mike. I use JRiver to implement BEQ filters, and it works really well. Some movies, like Pacific Rim and The Avengers, are a completely different experience with BEQ (assuming you have a sub that can dig deeper than 30 Hz). I create a zone for each film I want to BEQ, and then use the zone switch feature in JRiver to automatically switch zones when I start the move. I'm not near my HTPC right now, and I've had quite a bit to drink (celebrating the Cubs' victory in the NLDS against the Cardinals), but if you're having a hard time figuring out how to implement it, I might be able to put together a short HowTo in the next couple of days.
  25. 1 point
    Yes, this can seem like a lot of work to do to just watch a movie, and I have to admit I do not bass-eq every movie I watch, even if there could be a significant increase in experience due to the improved sound. What I was hoping for is more awareness, so that content providers eventually see the problem, and start making better products with more consistent and proper sound quality, because that is the real solution and bass-eq would become obsolete. I believe better sound would benefit the providers due to increased sales and interest in their products. To make that happen requires knowledge - producers will never know what is missing until they experience the difference.