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  1. Yesterday
  2. Small yet Mighty. The tale of the 12's

    Chapter 2: The Organ Donor I now faced a dilemma. Each Sonotube contained 2 subs. My other nearfield sub had 4 drivers. I was going to have trouble level matching my rear subs. Deciding to use 4 drivers, I now needed a new design for this back sub. But it needed to be the "right" design first time around. Putting 2 Sonotubes behind my recliner was out of the question. Building a dual opposed box presented layout problems, and resulted in very low WAF. A downward firing fake "hope chest" would be too long for the space. Dual opposed Up/Down also had no WAF. Front/Back dual opposed would likely shake my surrounds and any pictures off the wall. I could go with 2 front firing, 2 downfiring, but that meant really tall legs, which likely wouldn't work. I was stuck. I looked at any sub build I could find, hoping for inspiration. I lost myself in Infinite Baffle, Push/Pull, and all manner of unique layouts. I saw a guitar speaker with 4 front firing 10's. It was ugly as sin, but it wasn't that big. Light shone down from heaven. This was it. 4 drivers front firing, stacked in 2 rows of 2 each, butted up against the wall. It was basically a compact version of my nearfield sub. Whatever I did, it needed high WAF. I don’t have woodworking skills, and good quality wood can get pricey. So I started looking for a pretty "shell" to build my sub inside. I decided to commit a AUDIOPHILE SIN and take a vintage piece of audio equipment and convert it into a sub. With much shame, I looked at antique radios, consoles and all manner of things. Then it happened. I saw an ad for something the seller called a "Reverb" box. I had no idea what it was but it looked pretty, and had 4 10" drivers inside of it and a make/model number of Hammond PR something. Down the Google rabbit hole I went. I finally locked in on "The One". A Hammond PR-40 Tone cabinet. The Hammond PR-40 is meant to connect to a Hammond Organ. It has 2 15's and 2 12's in a 37 ½” high, 31 ½” wide, and 18” deep form factor. Its "just right". Tall enough to put stuff on, and more a rectangle than square. It also isn't much deeper than a Sonotube would have been. I scoured the web for the "right" PR-40. Finding units in Chicago, and Peoria IL, I messaged a local friend to see if he would want to buy any of the parts out of these for the shop he runs. They are tube amp powered after all, and use "ok" vintage drivers. He said he'd be willing to pay about 50 bucks for the parts if they were all there. That put both units at a very good cost, but there would be travel time and gas involved. Do-able, but would require a harder sell than I wanted to do at that time. Life got in the way, and time passed. Being a horrible person [emoji14] (see backstory), I had contacted both sellers for more pictures, so I had their email addresses, however I never actually bought either unit. Finally ready to revisit and move on a unit, I messaged my friend to see if he still would buy the parts out of them, and he surprises me. "Sorry Dan, not interested….." My heart sank. "Because I picked one up last week. You interested in the cabinet?" My breath caught in my chest, I messaged back "When can I see it?" "I'm eating a (local Mexican place). How about after?" "Done." I meet him at his storage unit, and there she is. A PRISTINE PR-40 in gorgeous walnut, the finish I needed to match our existing darker mahogany/espresso furniture. It was all still in one piece, tube amps and all. Forgive me Father for I have sinned.... For 25 bucks, I took the cabinet, and he took the internals. It came home with me yesterday. It cleaned it up very well, and I'm now starting to move onto the build I've dubbed the "ORGAN DONOR" [emoji14]. I will be posting a TON of pictures later tonight (after I go to confessional ;):D), but suffice it to say, this unit is put together REMARKABLY WELL, and it's all Modular. The top came off with 4 screws, the front grill is attached with screws, making my job cutting pieces out extremely easy. One thing I didn't know but is ICING on the cake, is that the grill fabric uses individual strands of wire in it. You cant see it, but its there. Why do I care? Well I've got 3 dogs, a cat, and 2 kids. So it should significantly help deter them from poking drivers, and the grill fabric can handle some poking without needing replaced. The "only" flaw is that the top grill fabric has a tear, however my friend has a tub of similar older grill fabric that I can use, and he thinks he's got a perfect match for the front grill fabric. Some pictures. First set of drivers. I haven’t yet taken one of all of them together. Here is the Hammon PR-20 When I first laid eyes on her. After some cleanup Some other pictures of the unit. Even the top had a driver in it. The grill came off with 4 screws and cleaned up beautiful 3/4th used throughout. Very good construction. There is a very nice offset for the drivers. Need to do some thinking here. The area I need to think about from the front. Top needs a small amount of work. Just look at that detail in the grill cloth! Here are some rough ideas of what I’m planning (subject to change and updating at all times). I'm basically building a box inside whats there. The sides, top/bottom will be out of 1/2. The front and rear will be out of 3/4. The drivers will NOT have a double baffle. I plan to cutout "most" of the existing front baffle, and use the remaining outline as a "spacer" so its kinda like I have a double baffle. This will ensure the drivers have MORE than enough breathing room. The "ONLY" thing I am thinking is how easy/possible it will be to remove the 12's if I need to get acces to them. I may space them closer together, or perhaps install the front baffle in two pieces, with the cut going horizontal down the middle. That would let me unscrew, pull it forward and rotate it back and then get to the drivers.... Any thoughts appreciated
  3. Small yet Mighty. The tale of the 12's

    Foreword: I'm a guy who likes to go into detail. The devil and the beauty is in the details, small and large. The backstory in my mind is always important as it sets the stage for what's to come and to provide insight into why certain choices were made. This thread will, like all my others, be a slow burn. My builds are intentional. They progress slowly, after much internal angst and debate, complicated by my insane need to account for all variables, and over-complicate things :). Chapter 1: The Quest is born, and a Champion emerges from the forge! The Quest I fit in well here. I love BASS. I've been to a awesome theater in Chicago twice and each time I left wishing I could get 1/10th the sound hes getting. Then I made the mistake of visiting "The Savoy", where I confirmed the reality lived up to the hype. It didn’t help. On my bucket list is visiting Luke, and attending some of the other GTG's that happen out Iowa/MN way. All these guys have SPECTACULAR dedicated theaters. I dont. I console myself with the fact that we are in the top 1% of basshead crazy, but those guys I mentioned above…. They are the 1%, OF THE 1%. My wife is not a Basshead. If you look at the threads I've posted over the years, you will see I've thrown just about EVERY idea at the wall trying to emulate most of you guys. None stuck………. In late October of 2017, we visited my good friend in Iowa. He's a fellow bass nut, and we get along great. He was using 3 SVS cylinder subs with his JTR Triple 8's. While visiting my wife commented that she LIKED (or could tolerate more) the SVS cylinders. Wasting no time, I got her to agree to allow me to copy his layout, and keep the nearfield sub that is hidden behind our sectional. In return I had to sell my UM18 first, and self-fund the build. A deal was made. The QUEST HAD BEGUN! A CHAMPION IS FORGED I had acquired 2 backup Infinity's for my nearfield sub. I researched the SVS PC-12NSD to get its dimensions and port tuning. I then attempted to emulate it in WinISD using the Infinity 1260/1262. The Infinity modeled well in a 16" in diameter 32" tall Sonotube ported to about 19 Hz. Port velocity was in check, with decent SPL. The ports fit, barely, but it would work. . All that was left was to buy another driver. Unfortunately for me, I was BEYOND LATE to the Infinity party. The drivers were long since out of stock, so I had to find one on the interwebz. They showed up on eBay, but they were around 100 bucks or more after shipping. I decided to keep waiting. I started looking for other options and remembered the JBL CS1214. The ONLY issue was, after throwing it into WinISD, the drivers only modeled close in a SEALED box. SPL response was ALMOST identical with the JBL having more power handling. In a ported box the JBL looked HORRIBLE. It needed a box that was 2x the size of the one for the Infinity. So I pushed it aside and kept looking for Infinity drivers waiting for a bargain. All your Subz belong to us! It's now a week or two before Black Friday 2017. My UM18 had sold, and I was sitting on money waiting for the right Infinity to buy. I had my parts list ready to buy for the ported Sonotubes, but was waiting till I had my last sub in hand. Someone posted the JBL CX1200 was on sale for 45 bucks at BestBuy on Black Friday. The T/S parameters were identical to the CS1214. Knowing the CX1200 was the "updated" CS1214, I wondered what the CS1214 was going for now. A quick google search turned up the fact that Sonic Electronix had them on closeout for 25 DOLLARS….. INCLUDING SHIPPING!!!!!!!!!!!!! Consulting WinISD showed that a dual opposed 1214 build would make things simpler, and not lose too much SPL wise. I could ignore worries about port chuffing, I could add a shelf filter to boost response. This became a very viable option. It helped that one CS1214 wasn't too much more than the cost of the ports for each build. And they were NEW! I am a horrible person :)[emoji33]:p. Ryan will openly tell you this. Owning that fact, I told no one but my closest friends the deal I'd found, wanting to keep it all to myself. Like Gollum with the one ring. Mine, my own…. My precioussssssss The deal I was getting started to consume me. I started with 6 drivers in my cart. This was the minimum I needed to finish 3 DO Sonotubes. The JBL's and Infinity's would work together, so no need to go overboard ...................……..But I got sub drunk. 6 became 8, so I'd have 2 extras. Consumed by greed, 8 became 12 (so I could replace the 1260's and be using all JBLs). My cart suddenly showed 12 items. Then I did the unthinkable. My finger of its own accord moved before my brain even registered. "Submit" Looking at my invoice, I felt dirty. I pictured the face of the stock boy readying my order, seeing what I'd bought, and then how little it had cost me. His face turning to a grimace seeing their shipping costs. After shipping, I doubt they made a dime I thought that was the end. I was wrong. A few days pass and I am still consumed by the need to buy more of these drivers. It was only compounded by my fear I didn't have enough extras. To the Internet! By now, word of the deal had spread and Sonic Electronix was sold out (I'd like to think because I bought them out [emoji3]). That left Amazon, where they were 65 bucks new, no longer a screaming deal. I monitored the site, and a day later two drivers showed in their "Amazon Warehouse Deals" (I think thats what its called). These were Amazon returns that still worked but had damage to the packaging, or the person just didn’t want them. 32 bucks a pop. I could stomach that. Ordered. They were mine. My total was now up to 14 subs [emoji33]. But the beast inside me was not yet appeased. I stumbled across a post from a buddy saying he had 2 drivers from testing, in factory boxes, he was selling. The post was stale, but I never saw any follow-up. I was going to be in Chicago for something else, and may as well add 2 more subs to my collection. A few weeks later the deal was done and I was on my way home with an additional 2. My bloodlust ended. With 16 drivers, there was no more room at the inn. I had already moved 8 of them to a friend's house for him to help me build the Sonotubes. That still left me with 8 at the house. It was time to start actually getting ready to build something [emoji33]. P.S. Here is a my floor plan showing sub locations.
  4. Big thanks to SME for fixing the images

    Way to go guys. Thanks for the help SME.
  5. Big thanks to SME for fixing the images

    Awesome to hear. Thanks SME.
  6. Fix for image links

    Strong work. JSS
  7. Big thanks to SME for fixing the images

    Terrific, thanks!!! JSS
  8. Last week
  9. Thanks Kyle! Actually, he jumped the gun a bit here and declared victory while the update was still running. NOW it's all done. Edit: Total count of posts updated: 169!
  10. SME worked very hard yesterday and today to write a custom python script which used the invision rest API to iterate each post, find issues, and fix broken <a> tags which had the url assigned to the incorrect parent tag. Invision was unable to perform the bulk fix, so we had to create a custom solution to get it done. If anyone finds anything else wrong with links or images please let me know, but as of now, the broken thumbnails should all be fixed!
  11. Fix for image links

    So the final word here is there is no provided too to do a mass fix. I don't have access to their db to do a mass conversion. What I'm going to attempt to do is learn the REST api (I tried to get it working but there is a problem with the headers right now so I have a support ticket for that. I will query all POST, parse them for broken HTML, change the text to correct HTML, then perform POST requests to edit each one. I'll need to do dry runs first then small tests then probably batch everything and while being careful. none of this is very easy so it might take some time... which is also limited since I'm trying to launched db 2.0 If anyone wants to help with this and knows web , rest and html requests, then I'm happy to delegate
  12. Bulding the Room2 listening room

    Posted this eminent solution on FB. It is basically useless for its intended purpose, but some will find it cool to use the phone to calibrate the stereo. Some phones will work, some will not. There are no speccs available, so you just need to try a phone and see what happens. If you have my horns, you can place the phone in the horn mouth, and see if you get a reasonably flat graph down to below 20hz - if you don't, the phone is useless.
  13. Bulding the Room2 listening room

    @SME, I only tested with a HTC, and that one looks good below around 1-2K, and down to at least 10hz. I have observed the SPL meter apps are popular, and they look nice and advanced, but I have always had my doubts regarding accuracy of those. Even a decent measurement mic needs to be calibrated, so what can you expect from a very cheap mic inside a mobile.. Dynamic range should be a concern for spl meter app, but for pink noise freq response can be assumed that the level is kept fairly low. I noticed there was not much correlation above around 5-8k, but below say 1k the response matched REW very well. Those spectrum apps must be set up properly, to show a graph with stable and correct response. This complicates the use. If I write my own app, it can be tailored specifically for this purpose, no settings or tweaking needed. If many phones have significant deviation from flat below 1K, that is actually a show-stopper for any app for speaker calibration. There is a point here were total complexity and cost becomes higher than the simplest REW + mic system - which actually works.
  14. Bulding the Room2 listening room

    A big caveat here is that the response of phone mics is a big unknown. I have a Google Pixel XL, and I recently installed an SPL meter / analyzer app. I figured it'd be helpful for a quick SPL measurement while playing music, without having to get up and go get my SPL meter. The app is pretty comprehensive and allows selection of Z-weighting for flat response, in the app at least. Unfortunately, the mic on my phone seems to have much diminished response in the sub range and also has poor dynamic range. IIRC, it taps out in the 80s dB, which is pretty much useless for measuring music that's loud enough to be fun. The sub response on the phone seems to be bad enough that it'd be useless for doing sub measurements. I wonder if they high pass it on purpose to improve speech clarity and reduce unwanted clipping? Oh well.
  15. Bulding the Room2 listening room

    How can you set up a bass-system if you have no measurement rig. Believe it or not, most people actually does not have acoustic measurement equipment. Here is how: 1. Download and install a spectrum analyzer app on mobile. 2. Download the <don't remember the name> full frequency range spectrum pink noise file from my web site. 3. Play the file on repeat and monitor what happens to the sound using the spectrum app. What can be fixed using this approach: - Setting level for bass system. - Adjust delay for main speakers. - Add custom parametric filters for horrible and obvious resonances. Very far from REW or similar, but compared to going totally blind this can fix integration and calibration to a level where many will be happy with the results.
  16. Questions about othorn,keystone, Xoc1 th18, DSL118 and others

    What type of design did you use the 18ipal and 21ipal in, bass reflex?
  17. Earlier
  18. Questions about othorn,keystone, Xoc1 th18, DSL118 and others

    I didn't test it after all , because I changed the 18"s with 21"s to use them in my own designs. I don't want to use that design anymore, it's better to use my own The difference though is huge, the efficiency and thermal stability are way higher than those of the SW115. I'll use the 18 IPal in one of my other designs and after that I'll use the 18Sound where normal drivers are needed. And the 21" Ipal is so powerful compared to anything else, the sound is so much better!
  19. Bulding the Room2 listening room

    Just to continue, in between measuring the V110 in detail.. Frequency response is useful, as a tool - when used right. Tonal balance, potential resonances, getting the relative levels correct. It is also good for presenting a nice, smooth graph, after some heavy smoothing. Impulse is nice to look at, I use step response for bass. But it doesn't tell much about the sound. There is little correlation between perceived sound and the shape of the curve. Decay is important. Here the peaks that shows in freq can be analyzed, if they are resonances those will stand out as ridges, easy to see. Waterfall is great for show-off. Spectrogram is the other important graph. It shows how the sound start and stop, and reveals problematic reflections and decay.
  20. Bulding the Room2 listening room

    @SME, more knowledge often reveals that things are more complicated than you once believed, and you realize you don't have a simple answer anymore. Frequency response is always the first we look at, and its destroys the day as we see it is not completely smooth, there are obvious flaws that needs to be corrected. As we learn more, gain more knowledge and experience, we realize this is just one visualization of what goes on, and reading a frequency response graph to actually get useful information out of it is not that easy. It is a steady-state visualization, and most of the signals we want to reproduce are transient in nature. Right now I am working on bass-systems. Trying to find universally applicable methods and rules to set up the subwoofers. Does not help with a very good subwoofer, if it is not set up and calibrated properly. And in most practical cases, room acoustics efficiently destroys the possibility to achieve perfect sound in a simple and predictable way. Measurements are accurate and very useful as a tool to compare before and after when doing changes on the system. But to be able to say exactly how it sounds, by merely looking at the measurements, that is not easy. When I observe something about the sound, I try to find a way to objectively measure and quantify what I hear. Then perhaps i can be better at predicting how it sounds, and find ways to improve faults. The first thing, though, is to verify what I think I hear - not as easy as one might believe. Often it is necessary to rig experiments.
  21. Bulding the Room2 listening room

    I agree that there should be no advantage to SBA/DBA solutions, provided that "you can manage to somehow get rid of the cancellation reflections", or otherwise remove the effects of the room using another method. In both cases, one achieves very smooth (near-anechoic) bass frequency response (when viewed without using smoothing) across a wide region of space. I don't have an SBA/DBA, but I do have DSP-optimized filters to achieve the above near-anechoic ideal. This condition is maintained up to about 65-70 Hz, above which I have multiple issues preventing me from maintaining an completely smooth response. This is probably an issue in most other types of near-anechoic sub systems, including SBA/DBA also. To be honest, I wasn't expecting to have to go back and shape the broad response by ear the first time, and I was even more surprised when I had to shape the broad response *in a different way* after I re-did it with new crossovers. More recently, I did an EQ overhaul of my mains speakers above 160-200 Hz only, and I had to re-do the broad shape of the subs *again*. These weren't minor changes either. Whereas before, boosting below 40 Hz even 0.25 dB caused the bass to go to mud, with the latest config, I was able to boost the low end by several dB without loss of intelligibility. So at this point, I'm not convinced that any particular way is better than another. If anything, my work with mid and high frequencies has convinced me that some early reflections are better than none, provided that the speaker is well-behaved. The main reason so many pros are convinced that early reflections are bad is because they are experienced with using monitors with poor off-axis response, and the elimination of early reflections prevents that nasty off-axis sound from corrupting the better on-axis sound. With good speaker design, that's no longer an issue. It does lead me to wonder if maybe early reflections are good for bass too, to a point. It appears to be well established that modal resonances have negative perceptual consequences, but do early reflections have as much impact as we think they do? We practically hear through early reflections for mids and highs. We may also do so for bass, but it probably depends on how much reflected sound energy there is in total and how well it is distributed in time. At lower frequencies, there is definitely a propensity for the sound field to become quite structured within the room, even if discrete modes are not obvious. This is a substantial open problem that I plan to devote more time to in the future. I would strongly caution anyone not to read too deeply into frequency response data. Because we hear pitch (frequency) and level, it is easy to assume that a frequency response (FR) plot tells us how different pitches will be emphasized, relative to one another. However, this is far from the truth. An FR plot with smoothing is largely meaningless because the smoothing discards most of the information that's relevant to perception in the first place. An FR plot without smoothing and with phase data does contain that information, but it is a terrible visualization of that information. Time-frequency plots like waterfalls and spectrograms are kind of a step in the right direction, but it is hard to glean quantitative information from them and the information within them is still not weighted very close to how perception weighs the information. All of this makes sense if you imagine what it would take to analyze an IR to determine the true spectrum of a source within the room. One must deal with a variety of acoustic interference effects and possible obstructions in the path of the direct sound. It takes some very clever processing in order to accomplish this with the accuracy that our ears and brain do. As can be seen, I'm rather short on good advice here. I am less confident in what I know about bass reproduction than I ever have been, having tried a variety of strategies and having failed, in the sense of not achieving any consistency. And that's just in one room. And this is yet another reason why I am very skeptical of the relevance of particle velocity, independently from pressure. Why? Because there's so much we don't understand about how pressure response affects perception. Unless or until one constructs an experimental apparatus in which velocity response can be varied while keeping pressure response *exactly the same*, no one has proven anything with regard to the relevance of velocity response. In practice, this kind of test is extremely difficult to do. Almost anything that changes velocity response will change pressure response in some way. "Close" does not cut it here.
  22. Bulding the Room2 listening room

    @maxmercy, I have never heard one with drivers mounted across the whole wall. There are practical problems with SBA/DBA solutions - obviously. And - I may be scolded for saying this - I am not convinced they add so much more than a more conventional system can do, when properly set up and calibrated, and you can manage to somehow get rid of the cancellation reflections. From the experiments when I first found that velocity has significant impact for low bass perception - especially in the 20 - 50hz range - I also had a set-up with very much of that powerful wall-of-sound feel, and part of this has to do with getting more velocity than you get in the steady-state free-field condition. Similar to what you can achieve with near-field subs. A DBA done right will get predictable and very good results. Other solutions often end up with one part of the freq range having some special and very good performance, but then there are faults in other places. The trick is to achieve that special part, but at the same time be able to fix the bad parts.
  23. Bulding the Room2 listening room

    Good to know. Have you every heard an SBA/DBA? JSS
  24. Bulding the Room2 listening room

    @maxmercy, yes, now, that is the question to ask. Fact is, I did not notice any huge difference. Even the 1x is as good as should be expected, and the 2x and 4x does not really have that much more, though they sound a little bit more tight and immediate, 2x a little better, and 4x even a little more. But I can not say there was a difference large enough in tactile experience to really differentiate the systems. The 1x hold up with bass-heavy music up to +3dB, enough for some tactile feel. But the larger ones can do much louder, and THAT makes a huge difference. ULF below 20-25hz is similar, as long as kept within limits. I still have 2x V110, so I can test some more, perhaps find a way to measure and get objective information.
  25. Bulding the Room2 listening room

    Kvalsvoll, With all 4 configurations, (1,2,4), for equal SPL with each, which configuration had the greatest perceived impact? JSS
  26. Bulding the Room2 listening room

    This is the tricky part. If the solution is to just eq to flat, it would be easy. But it isn't. Especially in the bass range, velocity and intensity matters. And you have to measure at different locations, at least cover different locations in height where the listener is located. Decay is important. Resonances will affect perceived tonal balance.
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