Jump to content


  • Content count

  • Joined

  • Last visited

  • Days Won


Kvalsvoll last won the day on July 17

Kvalsvoll had the most liked content!

Community Reputation

96 Excellent

About Kvalsvoll

  • Rank
    Ultra Member

Contact Methods

  • Website URL

Profile Information

  • Gender
    Not Telling
  • Location

Recent Profile Visitors

834 profile views
  1. Kvalsvoll

    The Bass EQ for Movies Thread

    Now I have watched half of it, and the impression of the sound is even better than the first brief screenings. ULF is well done, and it sounds much cleaner and less distorted than other movies with clipping and heavy limiter use. I used to believe that a spacecraft that runs out of fuel will just continue at same, constant speed in same direction, but you always learn something new, from watching this movie it is obvious they loose speed and eventually go to a halt.
  2. Kvalsvoll

    Bulding the Room2 listening room

    Testing new configuration in Room2. V6030 compact horns placed in the middle of the room, on sides. Quite close to the lp, nearfield-horn?
  3. Kvalsvoll

    Bulding the Room2 listening room

    Same as the Marantz and Denon I tested, it is very likely they share the same processing. Note that it is the DIFFERENCE (17.5ms/20ft) that is interesting, as this is the number that defines how much delay is possible on the closer speaker to make it match the farther.
  4. Kvalsvoll

    Bulding the Room2 listening room

    Maximum speaker delay in processors/receivers - a critical property, which is usually not sufficiently described in the manual or product presentation. Anyone know the limits for different types, brands? I seem to remember this issue has been up before, but oooohhh.. using the rest of the day searching will not happen, and new information and new models may be available. The problem: Getting the timing correct is crucial for high performance sound quality. For systems with front main speakers and separate bass system that means to delay the main speakers so that they sum correctly with the bass system in the frequency response AND IN TIME/PHASE. On most processors this is done by setting a distance on the different speakers. Typically, you set the front to the measured physical distance, and end up adding several meters for the bass system (subwoofer) - THIS WILL DELAY THE FRONT SPEAKERS. If you know what you are doing, you set the delay using measurements, so that timing and phase gets as good as possible to achieve. If you read on-line guides and audiophile magazines and pay no attention to how things really work, you set the distance for the bass-system equal to the physical measured distance, and conclude that subwoofers always sound kind of sluggish and is best switched off for music. Since you are smart, you want to do it the way that actually works to get better sound, and end up seeing that the distance entered can be quite huge. And in some cases it may be possible to reach limitations of the processor in use. Obviously this is a no-go limitation for a processor, so if you have an installation that you know will require large delays, you want to choose a processor that satisfies this requirement. You want to see a specification for this number. But this number is not in the brocheur or manual, it is not in any "test" performed by on-line or paper magazines - because the don't even understand why this number is important - so the only way to know is if someone have found the data. My contribution: Denon/Marantz processors, AVR: Max distance difference 6m / equal max delay 18ms. Devialet amplifiers: 20ms. Hypex DLCP and my SA-700 amplifiers: 15ms. (Though not relevant on the sub amp, becuase it is the mains that need delay.) Onkyo processors, AVR: ??? Some readers now realize I need those numbers for the Onkyo.
  5. Kvalsvoll

    X-curve compensation re-EQ

    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.
  6. Kvalsvoll

    X-curve compensation re-EQ

    @SME, you are aware that loudspeaker manufacturers tune their speakers ("voicing") according to power response and estimated typical room acoustic properties, and have done so for decades? If you look at on-axis measurements of typical hifi-speakers, they often have a response that deviates considerably from flat - look up some of the well regarded speakers on stereophile. This is because the radiation pattern changes with frequency, and by adjusting the response the "sound" can be changed into more balanced and neutral, but the measured charts seemingly show a "defect" speaker. Since most speakers have a pattern omni at low f and then narrowing towards higher f, they will radiate more power at lower frequencies. This causes some problems if you design a speaker with radically different pattern - a speaker with flat fr and flat power will sound different from these typical once, and since music is mastered for use with the typical speaker and room, it is necessary to alter the reposne of the flat speaker into something that gives a perceived tonal balance more similar to those typical ones.
  7. Kvalsvoll

    Bulding the Room2 listening room

    Compact Horn, basically a rear loaded horn with resonance chamber for extended usable range.
  8. Kvalsvoll

    Bulding the Room2 listening room

    Testing midbass horns in Room2. Calibration is complicated, and benefits in this system and room are questionable. This is just to ensure they work, and to learn how to set up and calibrate the system, so that the customer can receive some useful guidelines. Usable range around 45hz up to 200-300hz, but for cf above 150hz you should absolutely use stereo processing, so for a typical av-processor system with bass-management it can be used up to 150hz. Capacity around 120dB+, depends on how much power you have.
  9. Kvalsvoll

    The Bass EQ for Movies Thread

    Huge improvement (Star Wars - The Last Jedi). It already sounds quite good as-is, due to nice dynamics and the fact that levels are not pushed beyond clipping. But Bass-EQ improves this in a dramatic way. And you can increase mv a bit, I tried +3dB now, and that still works very well. Effects now have full frequency range, and anyone who experiences this difference will not need any abx-blind-testing to hear and FEEL this improvement. This is not about shaking the house more, it is about lifting the experience with improved sound quality. Mid-bass level is quite moderate, so a little lift from 50hz and up may give more impact on transients. This is exactly what sound quality is about - excitement without fatigue.
  10. Kvalsvoll

    The Bass EQ for Movies Thread

    Huge gain on the LCR+Surronds here in your BEQ, also more gain on the lfe than I would assume, but now I have not seen the spectrums, an the result looks fine to me. Just listened briefly to some scenes, and I wonder if just some boost below 20hz will do most of what is needed here. Also agree with your BEQ in that there is no need to reduce any mid-bass bump.
  11. Kvalsvoll

    Bulding the Room2 listening room

    @maxmercy, I use a modified 10" driver, it is an old discontinued seas. 10" is a good size - good area for sensitivity, not too large so it does not change the sound field it is supposed to measure. The 3x has less velocity in the important 30-40hz range, and a little less above up to around 120hz. Changing eq or delay on the BL back unit changes velocity response. The 3x sounds better because it fills in a dip in the response around 60hz, phase is same, spectrogram is a little better. The loss in velocity 30-40hz is noticeable. The increased v at ulf is more noticeable, because low freq noise stands out and becomes annoying - too much is not good. Further experiments can be to move the high-pass on the BL up in frequency, this will change the phase and perhaps make the velocity smoother - less ulf, fill in the dip 30-40hz.
  12. Kvalsvoll

    Bulding the Room2 listening room

    Sound field properties are important for how low frequencies are perceived. Sound field properties are the relations between pressure, particle velocity and intensity. Both level and phase of velocity relative to pressure can change significantly inside a small room when properties of the bass system are changed - position of sound sources, delay, eq settings. In Room2 I experiment with different bass system configurations, to find methods for setup that are repeatable and consistent. I experience differences even if the measured frequency response is the same. Some of those differences are caused by time-related issues like phase and decay. But some effects, notably at lower frequencies, are caused by differences in sound field properties. The system I test now is a FL FR + BL config - one additional unit located at the back of the room. In this setup there is and increase in velocity and sound power around and below 20hz, which causes more movement in the floor than desired, on many music recordings there is simply way too much ulf. I noticed this instantly, before doing sound field measurements - too much ulf. And indeed it looks like the BL back unit changes the sound field from 20hz and down, there is more velocity in the vertical direction. The way to fix it is to adjust the frequency response - reduce the level around 20hz. It gets much better, but still not perceived as neutral - there is too much ulf, and noise and unintentional ulf sounds become distracting. Also further up in frequency, there seems to be a clear correlation between velocity level and perceived bass quality - smooth is more neutral, more velocity is better and sounds more powerful and natural. Simply more fun. Above the 40-50hz range the situation changes, velocity is still important, but will be more of a measure of sound directivity. In the upper bass range phase and timing and frequency response is the important properties to focus on, as the velocity and intensity more or less follows due to the sound waves being smaller compared to room dimensions and distance to sound sources.
  13. Kvalsvoll

    Bulding the Room2 listening room

    Acoustic noise - fan noise. Signal noise is rarely a problem with power amplifiers. Plate amp is a no-go, requires cabinet building. They also tend to be more expensive. Crown could work, I see they have the xli 2500 with regulated fan. Or if we could find a used K2.
  14. Kvalsvoll

    Bulding the Room2 listening room

    Looking for a reasonably priced power amp for midbass use - 2 channels, around 500-1000W/8 ohms/channel, NOISE-FREE. Something like the inuke 3000, without the noise. I have a design for some very powerful and compact midbass horns, and now I found a customer for them, so if we can find a suitable amplifier they will be built and tested. My SA-700 can be used, but it is kind of overkill, and quite expensive. Any tips for such an amplifier? And no fan-mods or similar tweaking, it must work out-of-the-box.
  15. Unfortunately the de-clip does not work. Clipping is usually caused by lower frequency transients, and when the signal clips, a very noticeable duration of higher frequency content is lost, and this can not be accurately restored. Some more advanced plugins may have algorithms that try to restore by estimating what should be there, by looking at previous and after signal content, but it will not be possible to restore the content completely. For the lfe channel a declip can work better, but it requires gain adjustment to make room for the recovered transients, so the overall level will be reduced, and there is no gain in transient impact before gain is restored by increasing gain later in the chain. Clipping is annoying and destructive for sound quality because of the harmonics that are introduced. For lfe, the lfe signal will always be filtered somewhere later, so the destructive effect is not so severe. And a clipped transient will add up to 3dB headroom, you can see this by low-pass filtering a clipped signal, the result will look like a de-clipped signal and it will have a higher peak amplitude.