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Kvalsvoll last won the day on February 28

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About Kvalsvoll

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  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. 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.
  7. 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.
  8. Kvalsvoll

    Othorn - HT capable?

    Let me see if I got it right: You found a suitable horn (lilmike's F20?), a suitable driver for this horn (pro driver), the size is not an issue, you have cabinet builder ready to make them for you, and you have a friend willing to assist in calibration & setup. Build it. If you go for anything else, you will regret because you will always wonder how those horn would sound. Integration of these horns will be no more problematic than the sub you already have, the worst case scenario is that you achieve a similar result. It can be solved. But first - build the horns. No need to go deep into all potential problems up front. Now I am looking forward to read about how this turned out, how it sounds.
  9. Kvalsvoll

    Othorn - HT capable?

    The typical consumer subwoofer will never deliver a sound character similar to what you experience with your horns. But that does not make it useless, it fills in the deep bass below where the horns roll off, and for a lot of music most of the bass is reproduced from the horns. From what you write it looks like you have identified this difference in sound, and now start to wonder if it is possible to achieve a sound more similar to the horns at lower frequencies. And it is possible. But of course the lower bass will by nature sound different and give a different experience compared to the upper bass range, where most of the attack and kick is. One way to achieve this is to build something yourself, use a pro driver with limited excursion and high BL, place it in a ported cabinet that is too large and ported too low.
  10. Kvalsvoll

    Othorn - HT capable?

    If you plan to cross at 60-80hz, the alternative suggested by @Ricci could be a good alternative - a ported box. Use a pro driver, port it very low, choose a smaller driver for smaller cabinet size. For very low frequencies the size of the radiating surface does not matter so much, so the ported would give you much of the benefits of a horn, in a smaller cabinet, and much easier to build.
  11. Kvalsvoll

    Othorn - HT capable?

    I can not help you with the Othorn, but when I read "apartment" I am curious to learn how your neighbors cope, of course it is possible you only listen at moderate levels, but most people with capable systems tend to actually use it.. And those horns look great, by the way.
  12. Kvalsvoll

    Bulding the Room2 listening room

    And you need some method to measure it, doesn't need to be accurate or calibrated, just to be able to compare.
  13. Kvalsvoll

    Bulding the Room2 listening room

    I really should find something new for another article to post, so we can continue to go far-too-deep into something else, don't think we disagree enough to continue this one much more now.. I have one, most of the text is ready, there are pictures and measurements, perhaps tomorrow. I think @Ricci's post sums it up quite nice - mostly, not an issue, but, depends - some subwoofers, placements, floor and building issues, can cause problems. I still see your example here as surprising, even when considering that those subwoofers will create much more force than the very different V110. To give a substantial difference in tactile feel, there must be a very significant difference in vibration level. And this can be measured. It should show up on the frequency response, and can be measured with a mobile accelerometer app. It is actually possible to partially replicate this experiment; you could run only one driver active and short the other one - it won't be the same as single driver as the dead driver will still move a little, but should be enough to show a difference in vibration level form the subwoofer. With 2 drivers it should be dead, with one there will be motion. And just when writing this, I read another difference - from PORTED to sealed. That can also be a factor in tactile feel experience, but is it really that huge.. Maybe I should repeat the measurements comparing sealed and ported/horn. Difficult to seal off the horn output in a V110, and there may actually be too little output left even for a measurement only.
  14. Kvalsvoll

    Bulding the Room2 listening room

    I can assure you the floor is not more stable and firm and damped than any other typical house. It is a very old house, so the walls are heavy, but the floor does not seem to be more rigid than in typical newer houses. It gives a nice and pleasant tactile effect, from around 20hz and down towards 10-12hz. The problem you mention SME, about resonating and vibrating coupling between any loudspeaker and the floor certainly can cause audible problems, but it is also easy to fix, even those isopod products should work well for that. I consider this to be something that should be designed in to the speaker/subwoofer, so that the customer does not find the need to buy additional products to fix rattling and noises. When you have something capable of decent output full-range, clean, then all kinds of rattles and noises suddenly appear, often from outside the room you are listening in. On the processor in Room2 there is a small strip of tape attached to the acrylic display cover - it rattles. The spotlight assembly in the ceiling in The Moderate Cinema rattled, then there are the structural noises from the house, which can not be fixed so easily. The measurements were done with only one V110. Really no reason to complicate things by trying to decouple several subwoofer units.
  15. Kvalsvoll

    Bulding the Room2 listening room

    After looking into specifications - which I could not find, because there are none - for the product you mention, I now looked into a different product, where I was informed that the resonance frequency was 5hz. I could not find any information on the product's web site to verify this claim. I could not find any relevant technical information. So I stand corrected about the specifications for those products, and the description reads like snake-oil to me. If the spring is too hard, it will place the resonance right in the active working range of the subwoofer, and potentially make things worse. It also need to decouple in all directions - pivot, fore-aft, up-down, rotational. It is easy to verify if it can work. If the spring is compressed less than several inches/cm, it is too stiff. If you measure the deflection of the spring, the resonance frequency can be calculated, provided the spring is linear. A foam pad is not linear. If you make one large foam platform , sufficiently thick and soft to provide a low resonance, it would still be too stiff on the fore-aft direction, because the supported area is too large. A platform with springs in the corners could work. The foam blocks I used are only suitable for experiments, the subwoofer is not stable on top. But the most important observation here is that it makes no difference, even if the decoupling is made so that it significantly reduces mechanical coupling down to frequencies below working range. The floor in the room used for measuring this is what I consider quite normal for a wooden floor. But the subwoofer is placed close to walls, close to a corner. And in that location, the floor is much more rigid than in the center of the room, because the beams supporting the floorboards are supported only at the ends where the floor meets the walls. The subwoofer vibrates, it moves, and it is transmitting those vibrations to the surface it sits on. It just that the level is too low to be significant, compared to the effect from the acoustic sound pressure in the room, which acts on the whole surface of all walls and ceiling and floor. And the reports from people who tried this, says the same - no sound reduction for the neighbor. The V110 is different from the usual sealed box subwoofer with long-excursion, heavy-moving-mass driver. The moving mechanical mass is 118g - very low compared to the usual around 500g or more. But the driving force is similar or higher. And it is quite tall, creates a large momentum. The main force from the surroundings acting on the cabinet will be the acoustic load on the port exit, and this load is far less than the typical 500g mechanical mass. The 118g cone assembly does not move much, due to the acoustic loading, so even comparing the moving mass to a different subwoofer is not relevant. Still, this subwoofer certainly moves and vibrates. The older ancestor T138 in the media room is more lightweight, they move and have to be pushed back into location occasionally. A dual-opposite design is one solution to remove low frequency vibration, that actually works. But the floor still vibrates.