Popular Post mitchco Posted December 13, 2019 Popular Post Share Posted December 13, 2019 Chris, great write up and thanks for the shout out! You have done an excellent job of optimising your audio investment. I am glad you went with 2/3 of the room treatments. Your rooms decay time is right in line with industry standards and any more absorption would likely start absorbing the life out of the music.The Alexia's are indeed full range loudspeakers which allows the DSP to maximise their potential to 20 Hz to 20 kHz frequency response ±3 dB tolerance along the target curve at the listening position. It doesn't get any better than that! I hope you are enjoying the music! Mitch Matias, pkane2001, The Computer Audiophile and 1 other 1 3 Accurate Sound Link to comment
Popular Post mitchco Posted December 13, 2019 Popular Post Share Posted December 13, 2019 22 minutes ago, MarkS said: I have a really dumb question. With DSP, why does one need treatments? Can’t everything be done by DSP? Mark, not a dumb question. DSP can't absorb or diffuse the sound in a room. So if your room sounds like a bare room echo chamber, DSP can't attenuate the echo or long sound decay at higher frequencies. You need absorption and sometimes a combo of absorption and diffusion. DSP can manipulate the frequency response including the room plus loudspeakers at lower frequencies and just the loudspeaker's direct sound at higher frequencies. DSP can be used for digital crossovers, time alignment of drivers, excess phase correction and the list goes on. DSP can also reduce low frequency room resonances. For living rooms that are fully furnished, drapes, carpet, book cases, etc., it is likely that the rooms decay time falls within the spec as there is a range of operation. So in those cases, acoustic treatments are not likley required. Hope that helps. emcdade, skatbelt, The Computer Audiophile and 1 other 2 2 Accurate Sound Link to comment
Popular Post mitchco Posted December 13, 2019 Popular Post Share Posted December 13, 2019 HI @Jud Yes, for example Acourate and Audiolense can generate linear phase DSP filters that maintain linear phase throughout. Cheers, Mitch Jud and The Computer Audiophile 1 1 Accurate Sound Link to comment
Popular Post mitchco Posted December 14, 2019 Popular Post Share Posted December 14, 2019 Hi @Matias, not directly: https://www.hometheatershack.com/threads/linear-vs-minimum-phase-filters-in-rew-for-minidsp.151513/ Have a look at @SwissBear article on using rePhase and REW together: Also have a look at: https://yabb.jriver.com/interact/index.php/topic,87538.0.html Kind regards, Mitch Jud and Matias 2 Accurate Sound Link to comment
Popular Post mitchco Posted December 14, 2019 Popular Post Share Posted December 14, 2019 @yyz Agree with @firedog the UMIK-1 USB is great value being able to plug and play and not have to purchase a separate mic preamp and/or ADC. The accuracy of the mic is just fine for taking acoustic measurements. One potential issue is clock rate offset and/or clock drift between the input (i.e. the USB mic with it's own clock) and the output (i.e. DAC). However, John Mulcahy has this fixed in the latest versions of REW. Bernt also has clock drift compensation in Audiolense 6.x and Uli has a special version of Acourate LogSweepRecorder that can be downloaded here for taking measurements with UMIK-1. In the case of Acourate, which uses ASIO, one will need to download Asio4All as well. bunno77 and The Computer Audiophile 1 1 Accurate Sound Link to comment
Popular Post mitchco Posted December 16, 2019 Popular Post Share Posted December 16, 2019 1 hour ago, johniboy24 said: @The Computer Audiophile I have a question regarding the in-room response graph you posted. Are the before and after graphs even comparable? The "before" graph is at around 85db while the "after" graph is below 70db, so a lot quieter. I always thought if you put more energy into the room, so listen to music louder you will also experience more effect of the room (and more problems)? Hello @johniboy24 The before and after graphs are indeed at the same SPL. I have manually offset the "after" graph by reducing it's gain in REW so it is easier to compare when viewed in REW's overlays chart. We calibrate sound systems at "reference" level, which is approximately 83 dB SPL at the LP. This is because our non-linear ears, relatively speaking, have the flattest frequency response in this SPL range and usually this is the monitoring level set for adjusting the final tonal balance for mixes and masters from the studio. A good reference is Bob Katz, mastering engineer's topic on Level Practices. So for "critical listening" one wants to adjust the SPL to around 77 dB SPL (for highly compressed material) to 83 dB SPL (for wide dynamic range) on a sound pressure level meter at the LP if you want the most accurate playback as far as tonal balance is concerned. If using JRiver, I calibrate the loudness control in this range so when I have music on at "background" level, the loudness control is engaged to boost the bottom end to make up for the ears non-linear frequency response which becomes less sensitive to bass at lower levels than reference. The loudness control restores this balance to make the music sound full at lower listening levels. Hope that helps. skatbelt, DuckToller, MikeJazz and 1 other 1 1 2 Accurate Sound Link to comment
Popular Post mitchco Posted December 17, 2019 Popular Post Share Posted December 17, 2019 Hello. There are 4 common industry standard target frequency responses used to calibrate monitors in sound production control rooms. B&K, Toole and Olive, ITU and EBU 3276. And overlaid on one chart: Given that each target has a +- 3 dB tolerance, effectively each target overlaps one another, all with a downward frequency response at the listening position. This is because loudspeakers are omnidirectional at low frequencies with narrowing directivity at higher frequencies. The rising bass energy yields a steady-state room curve with a downward tilt. This is important to note because ones preference for one target or the other is based on a number of factors, all coming into play at once. Size of listening room, directivity index or polar response of the loudspeakers, distance from speakers to listener (there is a spec with a range), how much direct versus reflected sound is being heard at the listening position based on how lively or dead the listening environment is, also with spec and range of operation. All of these factors play into which target one prefers, with the common theme of how much or little high frequency response is required based on these factors. For example, in my room with narrow directivity loudspeakers and a fairly large and lively room (600 ms broadband decay time) with a 9ft equilateral triangle, I prefer the Toole Olive target response. Sounds neutral to my ears given this combination of loudspeaker/room. On the other hand, Chris's loudspeakers are wider directivity, also larger room. but with a 200ms broadband decay time. In order to hear the same perceived neutral response, more direct high frequency energy is required to arrive at Chris's listening position as compared to my loudspeakers in my room. Normally, I would deliver all 4 target responses at once for your loudspeakers in your room. As Chris has shown in Roon, one can easily flip through different filters as music is playing and choose what sounds best to your ears. Toole and Olive have shown in participant listening studies that as Floyd Toole describes, accurate and preferred are synonymous. Due to schedules, I delivered Chris one filter set at a time, instead of all 4. And started with the target with the most rolled off top end 🙂 LOL! Exactly what he did not need. The 4th target delivered, weeks later, should have been the first. I would hazard a guess that is the frustration. thyname, skatbelt, StreamFidelity and 1 other 2 2 Accurate Sound Link to comment
Popular Post mitchco Posted December 17, 2019 Popular Post Share Posted December 17, 2019 5 hours ago, CDJ123 said: Mitchco/Others: Specific to the discussion regarding DSP - I have a very nice pair of Focal Sopra 2’s in a bit of a challenging room that has been nicely treated. As a typical audiophile, I am always wondering if I can improve the sound. Since I use Dirac (which significantly helps), I occasionally wonder if getting a different pair of speakers would actually make any significant difference. If a speaker of this level has solid measurements (see “Soundstage!” National Research Council of Canada measurements) would another speaker that measures well (and after the application of room correction) actually improve things? Bringing a pair of Magico’s, Wilson’s, JBL’s, Vandersteen’s, etc., into my room to test out is really not an option. I would like to hear your thoughts. I do wonder if once a speaker is mostly full range, with solid measurements, if diminishing returns, becomes no returns with DSP/Room correction. Hi @CDJ123 welcome to Audiophile Style! Good question. The Focal's measure pretty good based on Soundstage anechoic measurements. As Floyd Toole says, "Frequency response is the single most important aspect of the performance of any audio device. If it is wrong, nothing else matters." He also says "bass response accounts for 30% of our preference." I would agree with his statements and mirrors my own experiences. I have had the opportunity to review several loudspeakers on this site in my room and "eq" them to be similar. Here is an example of the Kii THREE's and D&D 8c's with their frequency responses overlaid: https://audiophilestyle.com/forums/topic/54065-article-dutch-dutch-8c-loudspeaker-review/page/5/?tab=comments#comment-976157 As Martijn Mensink, the designer of the D&D 8c's says, "With just some subtle EQ the two could be made to sound very similar on most program material - to the extent that I might not be able to distinguish them in a proper blind test." I would also agree, and to my ears, it is difficult to tell the two apart. I have had that experience with a number of other speakers, including comparing large floor standers to small bookshelfs, using the same subs. The loudspeakers directivity index or polar response would be next in line as one of the more important attributes of a loudspeaker besides frequency response. I wish more manufacturers followed the ANSI/CTA 2034 A Standard Method of Measurement for In-Home Loudspeakers that one can download for free or see attached. It gives a good explanation as to why smooth off axis frequency response is important and too long to put in a comment here. The standard report also includes a "predicted in-room response" (see Figure 11) so folks can get an idea of what this may sound like in a typical living room. Of course, it can't account for frequency response below the room's transition frequency, which is why we use DSP in the first place as the room is in control below Schroeder and everyone will suffer from irregular bass response. And given that bass accounts for 30% of our preference, once you have heard optimized bass response from your system, it is hard to go back. While I love the voicing of my KEL LS50's there is not much bass output below 100 Hz, so they sound much better with subs (or even a woofer 🙂 So a long winded answer to say, yes with DSP there is diminishing returns if you already have a full range loudspeaker or sats and sub(s). Whatever one can do to get the full bandwidth with smooth on and off axis response is paramount. Then use DSP to optimise the low frequency response and tailor the HF response, if required, to fully realise the value of your audio investment. ANSI-CTA-2034-A.pdf skatbelt and The Computer Audiophile 1 1 Accurate Sound Link to comment
mitchco Posted December 18, 2019 Share Posted December 18, 2019 @yyz I have been aware of BACCH DSP for a while. No, I have not tried it, but sure would love to! Accurate Sound Link to comment
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