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Primare Knob

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  1. Item: 100 inch Acoustic Transparent Projection Screen. Price: Negotiable Location: Melbourne Region Hi, I am searching for an AT projection screen, preferably in a 100" 16:9 size. Larger sizes might be possible, but is gonna make things difficult for me. Cheers.
  2. WTB: 100 inch Acoustic Transparent Projection Screen. Price: Negotiable Location: Melbourne Region Hi, I am searching for an AT projection screen, preferably in a 100" 16:9 size. Larger sizes might be possible, but is gonna make things difficult for me. Cheers.
  3. Noob's adventure into accoustics

    Going forward, I have managed to confirm some things doing more measurements and tweaking. I have been able to time align my subwoofers properly using the Excess Group Delay graph as posted here. http://www.hometheatershack.com/forums/rew-forum/173114-approach-time-aligning-speakers-3.html#post1603002 The 70Hz resonance most likely has to do with the room's height node and less with the length node. When outputting a 70hz sinus signal the SPL changes a lot moving up or down, and not much when moving back or forth. Now the speakers and x-overs are set and aligned I think it is time to start looking into acoustic treatment. @Peter the Greek I am in contact with Gordon, and he is telling me that they are working on a new LF absorption design, which will be ready in a couple of months. No details (yet), but I gonna ask anyway.
  4. Bryston SP4

    It will be based upon the 16 channel version with the 4 channel XLR as an update path. "The ISP 3D.20 ELITE is ideal for theaters that need more than 16 channels, for example those requiring multiple subwoofers or perhaps configured for all 3 Immersive Sound formats. With 20 output channels and supporting all 3D audio formats, the ISP 3D.20 includes all the sophisticated control features that come with the ELITE Range." I am just wondering what they mean by configuring for all Immersive sound formats. DTS-X doesn't seem to need any specific speaker arragement and Atmos vs Auro 3D seem the have similair specifications beside the Voice from God speaker. All should fit well into 16.2 channels. And I assume here, that for large and custom theatre rooms the 32 channel version is more suitable. Time will tell where the digital Storm part ends, and where the Analogue Bryston part starts. The DAC section will most likely be the cross-over point. I like the Bryston sound and would prefer Bryston to do the DAC part.
  5. How about using wires and a curtain rail. You can use (2) roller parts on the rail to slide a panel from left to right and mount the wire fixing into the back of the panel, and re-fix at another point for adjustments. You could even come up with a single mounting point on the back of the panel with pre made adjustment points like a single vertical slat. When you like to have maximum flexibility you need to separate the horizontal movement and vertical movement. One movement is restricted to the wall (probably horizontal since the panel width will restrict this movement the most), while the other is restricted to the panel, if you don't want to drill new wholes. Hanging some horizontal timber slats with the minimum of screws which can be used to freely hang en rehang hooks without the need of drilling into the wall, might be practical, but will likely not win the beauty prize.
  6. Noob's adventure into accoustics

    @125dBmonster @Satanica Hi Guys, Would you mind having your discussion somewhere else? I am sure it has some meaning, but it is rather irrelevant to this thread. It would be better suited in an equipment thread. Thanks.
  7. Noob's adventure into accoustics

    I did find that out when I did multiple measurements with different phase settings on a single sub. I changed the phase setting on one sub based on the biggest SPL output, first using a LFE pink noise signal and SPL metering with mic, to later confirm it with a frequency sweep. The "good" range however is rather wide from roughly 45 degree to 135 degree with only minor differences in the combined SPL output, with the 90 degree generating the max combined SPL. Is the 90 degree phase setting on the sub generating a 1/4 cycle delay? If so how can I measure this? I have already measured the single subs with different phase settings and acoustic timing signal, but it never produced any differences when I measured them individual. But REW is consistently saying that one sub is delayed more then the other even when they are placed at identical distance, fed from the same single LFE output and should be identical subs. The only difference is that the delayed sub is using a 90 degree phase angle.
  8. Bryston SP4

    SNA just announced the new SP4 in the news. Bryston has partnered up with Storm Audio for the digital part of the processor. Based upon what storm audio is already offering we might get an idea about what the SP4 is going to be like. https://www.stormaudio.com/en/products/av-immersive-sound-processors/7807-isp-3d16-elite.html You can email James Tanner [email protected] for a preliminary PDF of the SP4 as posted on audiocircle. http://www.audiocircle.com/index.php?topic=155431.0 Looks like this is going to be an more expensive unit then the SP3 (which is going to coexist with the SP4), most likely absolutely out of reach for many of us.
  9. Noob's adventure into accoustics

    If we are talking about phase in an SPL graph we are talking about soundwaves and how the phase changes with frequency? But what does a phase setting do on a subwoofer? And is phase measured in the time domain?
  10. Noob's adventure into accoustics

    After many more measurements I thought I had found the 70Hz disturbance. Opening the back door in the room and the 70Hz peak in GD disappeared when measuring the subs. Unfortunately the opposite happens when I open the door and measure the L+R speakers. The decay however is more in line with expectations with the door open, so I do believe the door is resonating at a certain frequency. None the less, I think I am done with moving speakers an LP, and by know have found the best possible position considering room constraints.
  11. Noob's adventure into accoustics

    I am working on both angles.
  12. I'll try to move as much discussion not related to phase regarding my room towards my own thread to keep this as clean and to the point as possible. Am I correct in thinking that, as room nodes are minimum phase, room nodes would not show up in the Group Delay graph? I have created a single graph from a collection of Excess Group Delay graphs in Photoshop. Red: Subs quarter way the width of the room at front wall, Mic position 98cm from floor, 120cm from back wall Blue: Subs half way the length of the room, Mic position 98cm from floor, 120cm from back wall Orange: Subs half way the length of the room, Mic position 110cm from floor, 120cm from back wall Green: Subs half way the length of the room, Mic position 110cm from floor, 110cm from back wall Purple: Subs half way the length of the room, Mic position 110cm from floor, 97cm from back wall But peaks that don't move in frequency suggest that they are room nodes and not SBIR. There is always something happening at 70Hz, which could be a first height (246cm) node, or second length (487cm) node (2x 35Hz) There is another recurring peak at 105Hz (70 + 35) Placing the subs at the quarter way the width of the room at front wall (Red) hardly produces any big phase change with the mic placed at the quarter length in the back of the room, regarding the room length node (35, 70, 105, etc) but the SPL graph is showing a different story. So, which information do I use where? As it looks, phase changes aren't always creating problems in the SPL graph, but can create problems in the decay time.
  13. I wonder if it could be that the back wall or door is resonating. The back wall construction is 70mm studs, 16mm plywood and 13mm plasterboard on both sides with insulation. The large part of that wall is part of a small toilet area.
  14. What about the different decay impulse over time between 110cm and 120cm. Does that make sense? At 110cm the 70Hz decay is linear over time, but at 80ms it has a huge rise, which peaks above everything before 80ms.
  15. Dante Network Adapters

    The hole idea is to use them near an end point in a networked audio setup. Instead of running long balanced cables. The great thing about the audio network setup is that it has very low latency and can sync clocks with multiple channels. Multi room audio would be a good example. I know that some come included with a DAC and PoE. Technically you could run a HTPC with a Dante multichannel output digitally over an Ethernet distribution network straight into powered speakers as a HT setup.