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Everything posted by Kvalsvoll

  1. A lot has happened since the last update here. I mainly use facebook to post short messages and pictures of what is going on now, and articles are on my web site in the blog-section, products on the product page. Which means no focus on updating this thread. A new very small speaker has been developed, it was due for launch and presentation, and then you-know-what arrived as a free gift from someone I am not very pleased about at the moment. So launch is now postponed indefinitely, until people are able to show interest in speakers and sound again. The new F205 has a preview pag
  2. This is great, and as you mention - the challenge is how to market sound. The irony is, that it would be easier back in the 80ies - 90ies - before the internet. Today, you are easily lost between all other outstanding and remarkable offerings, and they have a larger marketing budget. Describing sound quality in text is a hopeless exercise. You can never have the receiver understand what you mean, until they actually experience it in person.
  3. Yes, the crossover turns phase 90 deg for each pole, and the resulting delay is not that large compared to what room reflections can do.
  4. I chose processing that resembles some of the problems I see in measurements from systems around. I have some measurements from customers now, and some of those follow the calibration process from start until the customer reaches the crossing between bored and good enough. Some subwoofers introduce so high gd it is impossible to correct for in ordinary av-processors/receivers. Then there is the room. Yes, I could do a better job with frequency response accuracy. Sample material was quickly chosen, drums with more dry character may be easier to hear - or, may be not. Must try it,
  5. I just updated the article with spectrogram charts and subjective impressions from listening in Room2, now at more realistic volume.
  6. Delay is adjustable, and the rest is fixed in the dsp on the bass-system. For a text-book filter there is a delay, and if you adjust delay on mains to remove this, it wqill not sum correctly. But if the slope on the bass-system is different from the text-book, it is possible to end up with something that sums correctly and has zero delay. you end up with flat phase and flat GD.
  7. @maxmercy, yes, this is true. But it is actually possible to remove all gd/phase from the crossover itself, by adjusting slopes and delay. This is also possible to do higher up in frequency, in even in passive crossovers, but then you don't have the option of adjustable delay, so you depend more on simulations to get it right.
  8. Audibility of group delay at low frequencies: https://www.kvalsvoll.com/…/audibility-of-group-delay-at-l…/ It is then confirmed and proven that group delay at low frequencies is audible. This means timing - GD, phase - matter for sound in the bass range, it is not sufficient to tune towards a flat frequency response alone. (Yes, we knew, told you so.. But, now it is actually proven with evidence in a replicable, described, controlled experiement.)
  9. The disaster here is of course the writer of that article will never read you comment, not because he does not want to or does not want to learn how this really works, but because he will never see it. The main problem with audio today seems to be more about communication - getting through with the message. We have the technical solutions, we know the theory, we know how to make this work in a practical audio system.
  10. Yes, something inside the cabinet behind the ports to control acoustic resistance. This is modeled and simulated, at least to some extent. Dimensions and placement of ports, cabinet volume, is nice to get reasonably correct. The damping will always need some experimenting, because it is not straight forward to get good models of the acoustic properties of the damping material. This is not a problem, it does not take much time to get it right. The cabinet does not need to be very deep, but the location of the ports, baffle width, speaker driver size all matter for resulting response.
  11. New articles in the blog-section, published quite recently: The F105 loudspeaker - review-style article on this small loudspeaker with some quite interesting technical solutions: https://www.kvalsvoll.com/blog/2019/04/23/the-f105-loudspeaker/ (Use google translate for the text that did not make it through the author's translation service.) Bass and sound quality - 4 real world examples: https://www.kvalsvoll.com/blog/2019/03/10/bass-og-lydkvalitet-4-eksempel-fra-den-virkelige-verden/ (Use google translate, it continues to improve, and has now reached a performance
  12. There was some discussion about some subwoofers that were linked to my name, in a different thread. Please feel free to ask or comment, and you can use this thread, no need to start a new one. If you go to my web site, you will see product presentations of the subwoofers I sell, and articles related to those subwoofers and bass in general. All presentations and product info are available in English language, most of the articles as well. What I am going to say now, may seem a little strange: I am not on data-bass to promote my products and services. Actually, I am not that keen
  13. No place for this in this thread, regardless of what is for sale or not. Go to the Room2-thread, I will make a comment there.
  14. If you have questions about my designs, you can ask in the Room2-thread, I may even answer. As for this specific construction pictured above here, that is not something I sell or build, this is a diy based on technical input provided by me.
  15. Guide to this season of GOT: 1. Go to Braavos to lend money in the bank for a new screen with night-vision. 2. Valyrian steel is definitely not required for the magnet system in your subwoofers. 3. Most important step: Go to data-bass and learn how to apply bass-eq. Oh, it's this thread. 4. Turn it up and enjoy. Part from the non-existing low bass the sound is good enough.
  16. New article about bass-system calibration: https://www.kvalsvoll.com/blog/2019/02/10/calibrating-a-bass-system/
  17. Small will still not be the same, because directivity will be different. Unless directivity is designed to be similar, of course. Active does not make any difference, and eq can not change decay profile, which is a result from room and speaker radiation. The solution lies in the physical acoustic design of the speaker. Active is necessary to solve some issues, such as crossover at lower frequencies, and delay between drivers where this is necessary. Proper crossover between bass system and main speaker must be active, because it is too difficult and costly to make a passive network t
  18. English version of the small speaker article: https://www.kvalsvoll.com/blog/2018/10/20/can-a-small-speaker-perform-like-a-big/ To discuss or comment, you can reply here in this thread. Small speakers without the sound compromise have always been wanted, and there are several new speaker offerings claiming the problem is solved - small sounds as good as huge. But it doesn't. This article tries to describe some of the most important reasons for this.
  19. New article about power requirements: https://www.kvalsvoll.com/blog/2018/12/02/how-much-power-do-i-need/ Info on power requirements for active or bass-managed systems is interesting - reducing the bandwidth does not reduce peak power requirements.
  20. Doing a proper bass-eq takes time and effort, and as you do more of them you start to notice that experience is nice to have. Yes, you need to listen, and since a movie is quite long, with lots of scenes and sound effects, this will be a time-consuming process if you want to be sure you get the best possible result within constraints given by you skills and the soundtrack you have. But we only watch the movie once - usually. Kind of like how GOT (a person living in Norway) put it about skiing - the conditions really does not matter when climbing and skiing a mountain, because you only sk
  21. I see your point where individual bass-eq for all channels including surround is the ultimate solution, and can in some cases be a significant improvement, as when surround effects that has wide frequency range are not mixed in to the lfe channel, and those surround channels are filtered somewhere in the process. But still, I claim most of the performance gain with bass-eq can be had with beq on the bass-managed signal, which is the only practical solution for most people. Then you miss out the correct correction for surround - as well as lcr - because the adjustments you make are weighte
  22. It is not strange that something with +60dB ulf boost on surround channels looks odd, because this is very likely mostly noise. Keep in mind that no studio or cinema can reproduce low frequencies on the surround channels, whatever is there below around 50hz was never part of the sound design. The most important to fix is lfe and lcr, that is where the big difference lies.
  23. @3ll3d00d, I do follow and appreciate the excellent work you have done on the beqdesigner. Especially since it is obvious now that the best we can hope for is movie sound that responds well to bass-eq, there will never be a situation where you can assume the sound is perfect from the provider. I also follow, or at least make an attempt to see what is going on in the soundbar-forum thread.
  24. Apply gain -10dB before filtering, that should leave enough headroom. After applying all filters, you can fix the gain (+10dB), and perhaps give a warning if clipping occurs. But remember that for dsp processing during playback there may be more headroom available, if the dsp is located after master volume in the signal chain.
  25. I may be the only one trying to run beqdesigner on linux, so it's like you did this for me, and I feel obliged to test it. I will see if I get the motivation to give it another try, requires some effort to upgrade to the right version of everything, including the right python version. I will report back when I have tried it, and thanks.
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