Madaeel Posted February 25, 2015 Author Report Share Posted February 25, 2015 Did you read what she said to me?!! I'm scared of that woman. So I'm gonna have to wait till she goes to work haha. Link to comment Share on other sites More sharing options...
MemX Posted February 25, 2015 Report Share Posted February 25, 2015 Brave man Link to comment Share on other sites More sharing options...
Madaeel Posted February 26, 2015 Author Report Share Posted February 26, 2015 Smart too. It'll be back up in the living room before she gets home. Link to comment Share on other sites More sharing options...
dominguez1 Posted February 26, 2015 Report Share Posted February 26, 2015 Actually, if I ever get a response from the manufacturer, we plan to look into the whole sound pressure vs acoustic particle velocity phenom. If there is sufficient evidence and good results, I'll def design a near field sub accordingly. IMO, it won't have to be DO 15s or 18s, though, and there will be a formula for level vs distance for matching output with far field. If this pans out...talk about innovation . A commercial offering for scientifically dialed-in nearfield sub(s) that integrate with a farfield sub response? Yes please... Link to comment Share on other sites More sharing options...
Madaeel Posted February 26, 2015 Author Report Share Posted February 26, 2015 I think this thread needed a graph. Here's the subway scene from Cloverfield. Link to comment Share on other sites More sharing options...
Bossobass Dave Posted February 26, 2015 Report Share Posted February 26, 2015 I think this thread needed a graph. Here's the subway scene from Cloverfield. CFsubway.jpg That looks like an SEQSS curve in line and mic'd at the seat? I'm glad you brought up Cloverfield. I'm missing something with that disc. I'm sure I'm referring to the DVD version, 5.1. I've compared it to WOTW bridge scene without changing any settings, digital measurements: There's no comparison. Clover is weak sauce. Is there a version or setting that I'm missing? Link to comment Share on other sites More sharing options...
Madaeel Posted February 27, 2015 Author Report Share Posted February 27, 2015 Huh. The bridge scene is pretty potent too but that's the subway scene. Remember when the soldiers fire the rockets and guns right before they run into the subway? Well that's those shots and then the creature steps down right in front of the steps to the subway, and that was actually run with the subs -2db from ref(yes you read that right they were not hot). The bridge scene looked pretty similar save for a little extension and I was gonna post it too but it seems every time I go to post a graph the limits keep dropping. I think the max size for a file was 411kb. I want to ask Kyle(or Josh) about that. I just keep resizing till I get it under. Anywho that's the Bluray in DD I believe. I'll double check when I get home tonight and let you know for sure. I remember Ethan and I used those scenes in the shootout and they were some of our favorites. I thought the execution in that movie was one of the best ever. That should be killer in your room. That was with the boost set to 6db, filter on 10hz and yes mic'd at the seats. Link to comment Share on other sites More sharing options...
BeastAudio Posted February 27, 2015 Report Share Posted February 27, 2015 That would be amazing. If you build em put me down for two so I can do 15db hot near field. Too much....wayyy to much unless you want to impress on some music tracks that are just bassfests. Link to comment Share on other sites More sharing options...
Madaeel Posted February 27, 2015 Author Report Share Posted February 27, 2015 Yah I know hence the lol. That was for Dave since he always teases me about running 15db hot. Dave that was the Bluray and I can't post the Bridge scene since I met the limits somehow. Anyway I'll email it to you. The bridge scene is brutal and looks just like WotW cept for the extension. Like I said that scene should be amazing in your room. Something definitely isn't right. Link to comment Share on other sites More sharing options...
mojave Posted February 28, 2015 Report Share Posted February 28, 2015 One thing that escapes most people though is what amplifier is not going to be deep into clipping its outputs when sent 8+ volts? Some pro amps will handle that much voltage without clipping the input stage, but you'd have to set the input attenuators to almost minimum to get the output stage to not be heavily clipping itself. +24 dBu is 12.28 volts. Most mixing consoles output +24 dBU and so do many pro audio audio devices (RME, MOTU, SSL, Lynx Studios, etc.). A lot of pro amps can handle +24 dBu (12.28) volts on the input due the requirement to work with these mixing consoles and audio devices. As an example, the QSC GX series has a Maximum Input Level of +24 dBU and the Powersoft K20 has a Max Input Level of +27 dBU. Link to comment Share on other sites More sharing options...
Ricci Posted February 28, 2015 Report Share Posted February 28, 2015 I know but it is the output stage I was talking about. Not the input. The amp will be at full output and either clipping or limiting well before getting to +24dbu input levels, unless you have the input attenuater at nearly min. Link to comment Share on other sites More sharing options...
Infrasonic Posted March 3, 2015 Report Share Posted March 3, 2015 Yah I know hence the lol. That was for Dave since he always teases me about running 15db hot. Dave that was the Bluray and I can't post the Bridge scene since I met the limits somehow. Anyway I'll email it to you. The bridge scene is brutal and looks just like WotW cept for the extension. Like I said that scene should be amazing in your room. Something definitely isn't right. Why not host your images somewhere else such as: photobucket or imageshack? Link to comment Share on other sites More sharing options...
Madaeel Posted March 3, 2015 Author Report Share Posted March 3, 2015 I was just hoping Kyle or someone knew why it was doing that. Idk if that's the limits for the thread or what. I'll prolly create an account on photobucket. Link to comment Share on other sites More sharing options...
Bossobass Dave Posted March 22, 2015 Report Share Posted March 22, 2015 If this pans out...talk about innovation . A commercial offering for scientifically dialed-in nearfield sub(s) that integrate with a farfield sub response? Yes please... No white BBs in the works, sorry. We could always build a white box for a one-off. Actually, if I ever get a response from the manufacturer, we plan to look into the whole sound pressure vs acoustic particle velocity phenom. If there is sufficient evidence and good results, I'll def design a near field sub accordingly. IMO, it won't have to be DO 15s or 18s, though, and there will be a formula for level vs distance for matching output with far field. Adam sent me to a discussion in the ULF thread regarding your latest test and asked me to comment if I got a chance. First, the only hardware to measure PVL is made by a company in The Netherlands called Microflown. I have as yet been unsuccessful in getting pricing and availability of their PVL sensors. I'm not killing myself but I have made inquiries with no response. Some things I know that might relate to the discussion referenced above: The sound pressure levels and the pressure velocities had different spatial distributions in the chambers. This difference derives partly from the fact that sound pressure and particle velocity are 90º out of phase, and under resonant conditions the spatial variations in each of these parameters caused by wave interference would be segregated by a quarter wavelength. Secondly, the price paid for dialing 2 FRs out of phase and bumping the level is much higher THD. Any time you reduce the fundamental without reducing the harmonics to the fundamental, THD rises accordingly. In the case of the close placed sub and farther placed sub in Dom's room combining to reduce the 28 Hz resonance, the price paid is THD rising by roughly 22% at the resonant frequency. This is shown somewhat in the posted sine wave test: Of course, this is coincidental in Dom's (and most of ours) case as I'm sure the flatter result of the combined sub placements was not planned in advance. And, I would still much prefer the flatter response and keep THD down by employing capable enough subs. Another observation is the irrelevance of the group delay difference between the sealed and ported subs or, more specifically the mention of ported phase shift below tune. As you can clearly see, the ported sub's roll off has zero effect on the sealed sub's response in the ULF region and the ported sub's roll off is exactly the same as it's GP roll off: More as I get time and gather more info about the relationship between SPL and particle velocity in an enclosed listening space... Link to comment Share on other sites More sharing options...
dominguez1 Posted March 23, 2015 Report Share Posted March 23, 2015 I gotta say, you are quite the master at overlaying images, responses, etc. No idea how you do that, but it's pretty cool. That last image where you superimposed 3 different images was ninja like... Glad your joining the discussion. On your comment on phase shift with ported subs and not having an impact on my sealed subs response: could that be because in a room, a certain portion (1/2) of a wavelength has to 'fit' in a room in order to have phase implications? I did the same test that I did above with a 15hz sine wave, and could only vary the spl no more than 1 db. What I understand is that 1/2 a wavelength must be shorter than the longest dimension of your room to have a phase impact. I've seen this in practices as I observe my frequency response changes while changing the phase. At a certain frequency (low 20's in my room), the combined response is no longer is affected by phase. Above that frequency, there's significant changes in FR as the phase is changed. coolrda brought this (3 consecutive posts on subject) up originally, and I have experienced similar. Link to comment Share on other sites More sharing options...
Bossobass Dave Posted March 30, 2015 Report Share Posted March 30, 2015 Just watched Exodus and capped a few scenes for the content forum. I also did a comparo of mic'd vs digital of chapter 11: The chapter starts out with just 3-20 Hz. Nothing audible, but my floor rippled. Cool as ice. I'm flat to 4 Hz at the seats and check out what I'm still not reproducing off this soundtrack as the digital cap's extreme low end melts away as it morphs into the mic'd sub's version. This one goes all the way to 1 Hz. How ya gonna beat that? YOU AIN'T. Hey Adam, I heard you tried the entire System 3 near field. What, the results are a secret? Link to comment Share on other sites More sharing options...
Madaeel Posted March 30, 2015 Author Report Share Posted March 30, 2015 Nope. Just on my 7th 12 hour day of work in a row....four more to go. Actually I'm at work now. Anywho enough crying let's get to it. Here's my FR sweeps. Blue is of course in the corners, red is them stacked on each end of the couch, and finally that awful green one is them separated behind the couch. The couch is 12' wide so there was roughly a little more than a foot between each stack. The couch is also in the middle of the room so no walls around the subs. As you can see near field with them separated was by far the worst response(not a word Dave!). I have some eq abilities in my 7030 and Paul and I messed around with it when they were stacked on the ends of the couch, and separated, and that was the best I could get it. Paul was running the sweeps while I made the adjustments on the 7030 so it didn't take long to realize that was as good as it was gonna get. Not to mention that null was one of the worst I ever saw and just wasn't worth any effort to fix. No surprise that with them close my low end response dropped. We knew that going in. What was surprising was that I actually felt below 10hz more with them nearfield then with them in the corners. The horse gallops in Pompeii and the ST ship roll I actually felt. It wasn't night and day between the two placements but it wasn't subtle either. What I didn't expect was even with them right behind me I ran to the limits at almost the same levels as before. I attribute most of this to the ULF as no matter where you put them they take the same power to get the effect. Far field you get room gain but lose over the distance since I'm on concrete. Near field I felt it but without the room gain I'm still running out of amp. So either way I'm screwed on a slab. Solution is of course a riser or move them to a room with a suspended floor. Dave told me beforehand he doesn't like near field because you lose the room gain the ULF needs. I understood that but since I'm on a slab and he's not I figured why not try it? Plus everyone else is doing near field. Only difference is I put the whole system so I know I would have enough displacement to get the ULF output I need. So here was the second surprise: With 40liters behind me and plenty of power I *still* didn't come close to replicating the feeling of ULF on a suspended floor. Not. Even. Close. Everyone who is doing near field subs on a slab I doubt they're even feeling the ULF unless they have a riser. Even if you do are you sure what you're feeling is ULF? It was only easy for me to tell on those two scenes in particular because Dave played them at his house. It's everything combined that gives you the feeling. A floor and couch that move, displacement, power, and roll-off. After this I just highly question whether most who claim to achieve and feel ULF actually are. All that said I did feel it more and that's why I tried it. I even told Paul I was going to keep them there. That is until I saw my response. Honestly I thought I felt more and was laughing at how much it shook the couch and then after I saw the response I realized I wasn't getting anything from 15-25hz. In that range is a LOT of tactile feeling. I said to Paul "ya know...now I don't honestly remember if it shook more with the subs in the corners". Well it just so happened that same day a friend came over. So I put on OHF and played the monument scene at ref with the subs at 10db hot. We all agreed it felt awesome. We moved the subs in the corner set the subs to 10db hot and HOLY HELL it felt way better!! I couldn't believe it. This whole week of them being nearfield I just didn't remember how they felt up front. Of course this was attributed to the FR and null. It just goes to show with movie and music transients it's hard to know exactly what frequency you're feeling. Certain ranges yes but when played together It's hard to distinguish. So back up front they went and I'm still happy with them there. Like I said I did feel below 10hz more near field, but at the expense of losing almost everything else. I enjoyed messing with them though and it was interesting to say the least. Jazzy goes home every year to see her family and when she does I'm gonna take the Raptors upstairs for a suspended floor run. Just gotta make sure nothing gets damaged. Link to comment Share on other sites More sharing options...
chrapladm Posted March 30, 2015 Report Share Posted March 30, 2015 While this doesnt really count as anything worth posting I will say it anyways. I dont have the funds yet for my second 15HST so I have my single 15HST sitting on my floor. It i on a 16mm thick x 600mm x 600mm dense foam square. Just playing free air. And I was watching a few different movies and some youtube clips and when the ULF's play my floor shakes quite bit. I always have to look at the driver to make sure I am not pushing it too far. Nothing bad so far. But I AM on a suspended floor. SO hopefully, even though a lot of mechanical forces will cancel, I look forward to just getting my singe cabinet finished. Then we'll see how much it shakes my floors. And for me I wont have a corner to place it in. Oh well. Anyways just my half a pennies worth. Link to comment Share on other sites More sharing options...
Madaeel Posted March 30, 2015 Author Report Share Posted March 30, 2015 How big is your room chrapladm? Don't get me wrong the BB I have in the living room shakes the entire upstairs like crazy. More so then the Raptors downstairs. When the Raptors play ULF though the upstairs feels like an earthquake. It's creepy actually. You think the house is gonna crumble. The couch downstairs feels like jello I just don't have that extra effect from the floor rippling. With ULF you need that. Now I'm also talking strictly below 10hz. I know most refer to ULF as <20hz but in this case I mean below 10hz. Between 10-20hz the Raptors downstairs shake my couch easily. Below that not so much. Problem is in any room, no matter the type of floor, one 15 ain't gonna cut it for anything below 10hz. You need multiples. My BB has two 15's but some of my ULF is going out through the walls, and then there's also just not enough displacement. Link to comment Share on other sites More sharing options...
chrapladm Posted March 30, 2015 Report Share Posted March 30, 2015 Well for me I will slowly end up with four 15HST's. My room is 13 x 18ft room. When I walk around my room the floors flex. I am only 210lbs and not a very heavy stepper. Link to comment Share on other sites More sharing options...
MemX Posted March 30, 2015 Report Share Posted March 30, 2015 The one thing I miss having moved to dual-opposed boxes is the floor wobble I got from my DF SVS - you could stand in the opposite corner in your socks and feel the floor move up and down very slightly lol Link to comment Share on other sites More sharing options...
Bossobass Dave Posted March 30, 2015 Report Share Posted March 30, 2015 Yeah, I couldn't live without my floor response. Keep in mind that the piston motion is not what moves the floor. Because the subs are in a dual-opposed config and are placed in the corners, the strongest point in the floor system structurally, there's no floor reaction from the piston motion of the drivers at all. It's strictly the combined pressure wave that moves the floor. That's always amazed me because it's a BIG floor with multi-LVL beams in the center. I don't know why the ULF is in chapter 11 at the beginning. There's nothing there video-wise to justify it. Maybe they used mics on set and the wind caused the ULF, I dunno. But, I had my head laying on a pillow on the arm of the chair and felt the pressure waves causing the ripple. No sound, just feel. It would suck without that. I'm drawing a house now of concrete construction with a dedicated HT and you can bet the farm I'm putting the seating on a suspended wood structure that's designed to offer support headroom but with flex room as well. Link to comment Share on other sites More sharing options...
Infrasonic Posted March 30, 2015 Report Share Posted March 30, 2015 Dave, have you ever experienced a Crowson system and if so did you like it? Link to comment Share on other sites More sharing options...
Madaeel Posted March 31, 2015 Author Report Share Posted March 31, 2015 Well for me I will slowly end up with four 15HST's. My room is 13 x 18ft room. When I walk around my room the floors flex. I am only 210lbs and not a very heavy stepper. That should be plenty in that room at just under 2000cuft. You'll definitely get that wobble. I'm not sure how much that one 15 is doing with ULF in free air though. Like I said it's hard to tell when playing transients. Yeah, I couldn't live without my floor response. Keep in mind that the piston motion is not what moves the floor. Because the subs are in a dual-opposed config and are placed in the corners, the strongest point in the floor system structurally, there's no floor reaction from the piston motion of the drivers at all. It's strictly the combined pressure wave that moves the floor. That's always amazed me because it's a BIG floor with multi-LVL beams in the center. I don't know why the ULF is in chapter 11 at the beginning. There's nothing there video-wise to justify it. Maybe they used mics on set and the wind caused the ULF, I dunno. But, I had my head laying on a pillow on the arm of the chair and felt the pressure waves causing the ripple. No sound, just feel. It would suck without that. I'm drawing a house now of concrete construction with a dedicated HT and you can bet the farm I'm putting the seating on a suspended wood structure that's designed to offer support headroom but with flex room as well. That's awesome. That's why I said if you didn't tell me ahead of time that ULF was in those scenes it woulda scared the crap outta me. That's the coolest effect when there's material below 10hz. I wanted to tell you I have been looking in to short throw pj's which would allow me to do a riser. Dave, have you ever experienced a Crowson system and if so did you like it? I haven't but I always say I would never use them. Even if they felt natural I just know in my head it's artificial. I could definitely use them in my room too since I'm on a slab but I get plenty of shake even without them. I know maybe if I heard and felt them I might change my mind but right now I have no desire to. You're system is ULF capable and then some Scott...you got em? Link to comment Share on other sites More sharing options...
Madaeel Posted March 31, 2015 Author Report Share Posted March 31, 2015 Hey Dom before I forget I did want to say some more about phase and PVL. It was odd when I had the Raptor stack behind the couch that I didn't get the increase in tactile sensation I thought I was. Actually nowhere near what I though I would get. What makes it even worse is Ethan has his A7s-450(still going ) firing directly into his couch and you feel it more then my subs, which are of course much more capable. Now don't get me wrong that thing drops like a rock around 25hz so there's no comparison between it and the Raptors below that, but above 25hz with it firing directly into the couch is definitely more tactile. I was thinking though the Raptors fire up and down. Most guys running near field, or all of them I'd imagine, are using subs that are front-firing. IF running near field increased the PVL then it shouldn't matter which way the drivers are firing correct?? One foot away or whatever distance near field is considered should be a lot more tactile then with them 10ft away in the corners if PVL is indeed higher when the subs are placed closer. I can't for the life of me think why that would be since even with the subs stacked and a decent FR it was still not impressive. So I'm thinking maybe all this has to do with Dave's theory of progressive constructive reflections. Dave correct me if I'm wrong but you say the rooms longest dimension has nothing to do with when you'll see boundary gain. It's just as the waves grow bigger the lower in frequency you go, they also become more constructive which is where your boundary gain comes in. Dave overlayed I think 7 or more different frequency responses from guys with varying types of room construction and size and almost ALL had gain at the same point. So if thats the case then if the driver is firing directly into the back of the couch it's taking the entire brunt of the wave before any part of those waves "escape" the room. However, if placed away from the couch no matter the SPL you are still not getting the full wave so to speak. It's being transferred into the walls around. Even though bass is omnidirectional, with the driver firing directly into the couch one could assume you would get more tactile sensation. Since a lot of what we feel in movies is above 20hz and escapes the room more than below 20hz once put behind the LP you of course feel them more..... I also could be talking out of my arse since most of this stuff is over my head. One more thing though. Dom I want to be clear on the out of phase theory. You said you can get the same PVL running out of phase and at 16db lower then running in phase. Again, correct me if I misunderstood, but you then said you could use that headroom elsewhere, like for ULF. My point was that you don't gain 16db of headroom at that frequency or any other when you do that. You lose that 16db since they're out of phase and fighting each other. Also I'm curious did YOU actually feel a difference even though the "meter" read different? I think it would be awesome if one of us got ahold of the Microflown meter. Strange they're so hard to get ahold of though. I just don't know how much trust we should even put in measurements with a phone. Not trying to be a smartass but seriously it's a phone...I can't imagine something that is primarily used for talking, texting, and porn surfing could measure anything remotely accurate for sound and/or velocity. Link to comment Share on other sites More sharing options...
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