Ricci

Ricci's Skhorn Subwoofer & Files

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Just one of the joys of being human - the constant quest for new and exciting things that teach us and stretch our brains :)

 

 

 

(Well, most of us - there are a depressing number of morons out there with no desire but to do as little as possible with their life...)

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It is more fun.

 

 

I like to throw in that while sealed gets it done, it's just so inefficient in the process (producing <Fs content). I mean, c'mon... to even sorta achieve what I want to achieve I have FOURTEEN 18's in a small room and it's still.... not enough.

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NOT ENOUGH?!?!?  In what way?  ULF Tactile response, midbass slam (I can actually believe that one in a small room), or just can't reach Ref? 

 

WTF will be enough, 'fear for your structure'  SPL?  'Fear for your life' SPL?  Nearfield pistol/rifle/shotgun/artillery blasts triggered by a threshold on the soundtrack?

 

Having been 100 meters away from a 155mm Howitzer I didn't know was going to send some hurt downrange (without hearing protection), I can tell you that 'fear for your f'ing life' SPL starts at around 140dB if it is not anticipated.  Do you really need that, and the innumerable 'what, can you repeat thats' you will ask servers in crowded restaurants for the rest of your life? 

 

C'mon man.....

 

 

JSS

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It is more fun.

 

 

I like to throw in that while sealed gets it done, it's just so inefficient in the process (producing <Fs content). I mean, c'mon... to even sorta achieve what I want to achieve I have FOURTEEN 18's in a small room and it's still.... not enough.

 

 

NOT ENOUGH?!?!?  In what way?  ULF Tactile response, midbass slam (I can actually believe that one in a small room), or just can't reach Ref? 

 

WTF will be enough, 'fear for your structure'  SPL?  'Fear for your life' SPL?  Nearfield pistol/rifle/shotgun/artillery blasts triggered by a threshold on the soundtrack?

 

Having been 100 meters away from a 155mm Howitzer I didn't know was going to send some hurt downrange (without hearing protection), I can tell you that 'fear for your f'ing life' SPL starts at around 140dB if it is not anticipated.  Do you really need that, and the innumerable 'what, can you repeat thats' you will ask servers in crowded restaurants for the rest of your life? 

 

C'mon man.....

 

 

JSS

 

I remember when a Bose Acoustimass module with two 5.25" drivers put a big grin on my face.  Later I thought a 12" Velodyne was just insane...then a 15"...then a 18"...then two 18s...etc...etc...etc. 

 

When I have GTGs and I see people's first exposure to 130db and now 140db I remember reacting that way but it doesn't last. 

 

I mean seriously, on the boards now days there's nothing special about a 8x18" system.  Crazy. 

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NOT ENOUGH?!?!?  In what way?  ULF Tactile response, midbass slam (I can actually believe that one in a small room), or just can't reach Ref? 

 

WTF will be enough, 'fear for your structure'  SPL?  'Fear for your life' SPL?  Nearfield pistol/rifle/shotgun/artillery blasts triggered by a threshold on the soundtrack?

 

Having been 100 meters away from a 155mm Howitzer I didn't know was going to send some hurt downrange (without hearing protection), I can tell you that 'fear for your f'ing life' SPL starts at around 140dB if it is not anticipated.  Do you really need that, and the innumerable 'what, can you repeat thats' you will ask servers in crowded restaurants for the rest of your life? 

 

C'mon man.....

 

Maybe he just needs a Crowson transducer surgically implanted into his diaphragm, although his answer will be interesting.

 

Due to the wide bandwidth and high sensitivity of the drivers I'm using for the subs and MBMs I'm building, I'll probably have > ~140 dB capability between 60-200 Hz or so, and I'll have > 130 dB capability from 20-1000 Hz probably.  I *might* be able to reproduce that Howitzer cannon, but I guess it depends on its spectrum.  That kind of capability scares me, like what happens if I have an equipment malfunction?  My DSP runs on a computer and is essentially running at 100% volume all the time.  What if I encounter a software bug, or a neutrino flips the wrong bit in memory and causes it to output white noise to all channels?

 

I remember when a Bose Acoustimass module with two 5.25" drivers put a big grin on my face.  Later I thought a 12" Velodyne was just insane...then a 15"...then a 18"...then two 18s...etc...etc...etc.

 

Wow, does Bose offer its Acousticmass modules with bigger drivers?  I have a hard time believing a pair of 5.25" drivers can do much of anything.

 

My first audio system other than a tape recorder was hand-me-down from my mom of an old Marantz stereo receiver and a pair of Bose Interaudio 4000, ported with 10" woofers.  The bass they offered, while a bit one-noteish, was very satisfying compared to most other speakers I'd heard and even some subs.  The weak point was the 3" paper cone mid/tweeter, which seemed to overload and distort badly before the woofers ever complained.  I remember thinking "The Matrix" sounded really cool on them, and I lived with and enjoyed them for over 15 years in all.  :)  I never thought of them as being that great (and they weren't), but they still sounded better than the vast majority of stuff in other peoples' homes.

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I am just joking around with Infrasonic, as he probably was above....Hence the "C'mon man" comment.  I am hoping his response will make me laugh, as he can pull very appropriate memes and other interweb hilarity at will.

 

JSS

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I *might* be able to reproduce that Howitzer cannon, but I guess it depends on its spectrum. That kind of capability scares me, like what happens if I have an equipment malfunction? My DSP runs on a computer and is essentially running at 100% volume all the time. What if I encounter a software bug, or a neutrino flips the wrong bit in memory and causes it to output white noise to all channels?

That is one of my nightmare scenarios. That and overall reliability are what keeps me from using a pc.

 

Bose uses an 8th order or 6th on some of their modules and none of them go low at all so they do leverage quite a bit out of the weak sauce drivers.

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...That kind of capability scares me, like what happens if I have an equipment malfunction?  My DSP runs on a computer and is essentially running at 100% volume all the time.  What if I encounter a software bug, or a neutrino flips the wrong bit in memory and causes it to output white noise to all channels?

 

....

 

 

That is one of my nightmare scenarios. That and overall reliability are what keeps me from using a pc.

 

...

 

 

This. Times eleventy bazillion.

 

I had an early home theater PC go nuts on me. Was not a pleasant noise. The sub made some awful noises, then some smoke. Killed the driver and the plate amp. My main speakers survived, but that was before I had any sort of real power on tap.

 

I'll run hardware DSP, not going to take that chance with software.

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It is more fun.

 

 

I like to throw in that while sealed gets it done, it's just so inefficient in the process (producing <Fs content). I mean, c'mon... to even sorta achieve what I want to achieve I have FOURTEEN 18's in a small room and it's still.... not enough.

 

My pair of 12s and I will just sit over here at the kids table...

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Looks like the Alpine S-15 might just work in one of these style of cabs after all.

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Really...  That was one of the first ones I tried, I must have screwed something up somewhere along the way.

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Attached quick sim doesn't look too bad. Tuning a bit higher with the vent and increasing area would help overall sensitivity & output some. Looks like a 500-750w amp would get it to rated xmax or a bit past. About 325L total. Rough guess is that would be a cab roughly 24x30x30. Big but not out of the ordinary for vented and way smaller than a horn that reaches as low. Could probably shrink it some and tune a little higher.

 

 

post-5-0-19222900-1481576843_thumb.png

post-5-0-10079600-1481577434_thumb.png

 

 

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This. Times eleventy bazillion.

 

I had an early home theater PC go nuts on me. Was not a pleasant noise. The sub made some awful noises, then some smoke. Killed the driver and the plate amp. My main speakers survived, but that was before I had any sort of real power on tap.

 

I'll run hardware DSP, not going to take that chance with software.

 

Bummer.  Were you not able to shut it down or pull the plug quickly enough?

 

FWIW, I don't distinguish that much between so-called hardware and software DSP because a hardware solution will almost always run some kind of internal software (i.e. firmware or microcode) anyway.  Both are potentially vulnerable to bit flips and bugs.  The big difference with a PC solution is that a lot more software gets involved (i.e., the operating system, hardware drivers, and even other programs that are running), so there's a lot more places where bugs can be present.  On the flip side, the memory protection provided by a modern operating system will often cause a bad program to crash quickly instead of misbehaving perpetually as a hardware unit with simple firmware might.

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The whole system was in a closet at the back of the room. I got there quickly, but wasn't able to save the sub and amp. Not that great a loss, but still. I still worry about my Media PCs flaking out on me,  but I still rely on them. I just don't use them to do the DSP stuff too. Heck, any more, my AVR can handle nearly all I need. I kicked around UltimateEQ for a while, decided against that for now. Have had no luck at all with JRiver. For now, DSP is in the iNuke, or in the MiniDSP. Have some FreeDSP kits to play with one of these days too.

 

I hear you wrt the code internally. Less code means less to go wrong. The typical DSP runs a dedicated code set that is hopefully designed to fail gracefully. A typical HTPC? Who knows? I've run lots of different flavors, some have been robust, some are absolute disasters. I think it was MediaPortal on Windows XP that baked the sub, but that was a long time ago. For frontends now, I'm typically running some flavor of Kodi on Linux, but I am still churning through things to find the right combination of what I am after.

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Yeah.  My DSP PC runs Linux and is dedicated to the task, so there's otherwise just system stuff running on it.

 

I wouldn't assume hardware DSPs are designed to "fail gracefully" though.  I learned the hard way that the MiniDSP OpenDRC-AN is very sensitive to static electricity, even on the outside of the box.  Once zapped, the thing stopped outputting most sound except for occasional loud pops.  I also observed the units behaving in similar fashion every so often after being power cycled.

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Missed this thread! I'll build one this weekend if you send over the plans. 

 

You got mail. That'd be awesome... :D

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You got mail. That'd be awesome... :D

 

We are close to making sawdust! Thanks for the help so far.

 

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Wow, impressive. I'd love to see how this turns out. Plan to throw in a couple of 21" IPALs in those?  :D

 

What gave it away? Hah.

 

Looks like Mr. dsl1 is going to have the very first one made. He's got some 21SW152's. Not sure what amps he has but even an Inuke 3k should make a lotta bass.

 

post-5-0-18820100-1482253428_thumb.png

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What gave it away? Hah.

 

Looks like Mr. dsl1 is going to have the very first one made. He's got some 21SW152's. Not sure what amps he has but even an Inuke 3k should make a lotta bass.

 

attachicon.gifSKHORN 21SW152-4 2.83v.png

 

I have a FP14000 clone.

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Are you doing a single? Going to run drivers in parallel or in series? 4ohm or 8 ohm drivers?

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