as an aside,
... can anyone offer any insight into how the adire shiva will hold up LONG TERM in a down-firing position?
adire claims that it's okay as far as magnetic field is concerned, .. but i have concerns about cone sag over an extended period of time
... can anyone offer any insight into how the adire shiva will hold up LONG TERM in a down-firing position?
adire claims that it's okay as far as magnetic field is concerned, .. but i have concerns about cone sag over an extended period of time
>in the final iteration, .. i may mount the driver fact downwards,.. although i'll then have to attach speaker terminals to the tube
====
Frankly, IMO speaker leads should be permanently attached at the driver. For bottom firing, route them through the baffle and seal the holes with flexible caulk.
====
>For more bass (and SPL) at your current length you can go ML TL by capping off the open end and adding a port (one of GM's favourites, I believe).
====
Yep. 🙂
====
>And guess what? For another ten bucks you can attach a 4' tube to the other end and have a Bose Cannon!
====
Though not a good choice where SQ is an issue.
====
>as an aside,
... can anyone offer any insight into how the adire shiva will hold up LONG TERM in a down-firing position?
adire claims that it's okay as far as magnetic field is concerned, .. but i have concerns about cone sag over an extended period of time
====
Of course it will sag some, but not enough to damage it when fired up or appreciably limit Xmax. What you have to look at is its mass (Mms) Vs compliance (Cms) to determine its offset, which is minimal in the Shiva's case since it has such a stiff suspension.
Per Adire:
offset (mm) = Mms*Cms*9.8
where:
Mms is in Kg
Cms is in mm/N.
Anyway, there have been many Shivas put in down firing HT sub designs since its inception and so far I've yet to read/hear of any sagging problems.
GM
====
Frankly, IMO speaker leads should be permanently attached at the driver. For bottom firing, route them through the baffle and seal the holes with flexible caulk.
====
>For more bass (and SPL) at your current length you can go ML TL by capping off the open end and adding a port (one of GM's favourites, I believe).
====
Yep. 🙂
====
>And guess what? For another ten bucks you can attach a 4' tube to the other end and have a Bose Cannon!
====
Though not a good choice where SQ is an issue.
====
>as an aside,
... can anyone offer any insight into how the adire shiva will hold up LONG TERM in a down-firing position?
adire claims that it's okay as far as magnetic field is concerned, .. but i have concerns about cone sag over an extended period of time
====
Of course it will sag some, but not enough to damage it when fired up or appreciably limit Xmax. What you have to look at is its mass (Mms) Vs compliance (Cms) to determine its offset, which is minimal in the Shiva's case since it has such a stiff suspension.
Per Adire:
offset (mm) = Mms*Cms*9.8
where:
Mms is in Kg
Cms is in mm/N.
Anyway, there have been many Shivas put in down firing HT sub designs since its inception and so far I've yet to read/hear of any sagging problems.
GM
GM:
and you come to this conclusion how? Have you sim'd one? Real world experince? Please elaborate...
and you come to this conclusion how? Have you sim'd one? Real world experince? Please elaborate...
Real world experience with both an array of originals and my own 'proof of concept', though I did it long before I ever knew about B***'s. It's not what you call a recent 'invention'. 'Cannon' is a very apt description IMO. Great for movie special effects if XO'd low enough. Mine wound up being stuck behind a friend's sofa with an old comforter tossed over it for a bit of movie 'rumble', but no way I want one to play high enough for music.
As always though, YMMV.
GM
As always though, YMMV.
GM
Bose Cannon
YIKES!
Both DrewP and I have have also built Bose Cannons and have had almost the opposite experience as yours -- deep clean authoritative bass (20HZ to 80HZ) for both music and home theatre. Certainly I will never go back to BR -- the Cannon is much less boomy, more open and airy
What dimensions did you use?
What type of material and how thick?
What driver did you use?
What are its specs?
In an AES article on the technology, the concept was described as "ingenious".
Instead of stuffing the pipe and losing SPL in order to tame it, a second shorter pipe is used to offest the peaks in the long pipe and vice versa.
But of course you know all this (yawn) and I am rambling while at the same time hijacking this thread.
Sorry guys...
Perhaps Planet10 can move this to the Bose Cannon thread?
YIKES!
Both DrewP and I have have also built Bose Cannons and have had almost the opposite experience as yours -- deep clean authoritative bass (20HZ to 80HZ) for both music and home theatre. Certainly I will never go back to BR -- the Cannon is much less boomy, more open and airy
What dimensions did you use?
What type of material and how thick?
What driver did you use?
What are its specs?
In an AES article on the technology, the concept was described as "ingenious".
Instead of stuffing the pipe and losing SPL in order to tame it, a second shorter pipe is used to offest the peaks in the long pipe and vice versa.
But of course you know all this (yawn) and I am rambling while at the same time hijacking this thread.
Sorry guys...
Perhaps Planet10 can move this to the Bose Cannon thread?
For Zobsky,
One thing to consider is where your first trasition from one tube to the next is, maybe jam a piece of see though fabric (or even regular screen material) between the tubes, or just wrap around the one being inserted. The screen will hold the stuffing away from the driver, so you don't have to worry about it touching.
Heres a visual example...
One thing to consider is where your first trasition from one tube to the next is, maybe jam a piece of see though fabric (or even regular screen material) between the tubes, or just wrap around the one being inserted. The screen will hold the stuffing away from the driver, so you don't have to worry about it touching.
Heres a visual example...
Attachments
>Both DrewP and I have have also built Bose Cannons and have had almost the opposite experience as yours -- deep clean authoritative bass (20HZ to 80HZ) for both music and home theatre. Certainly I will never go back to BR -- the Cannon is much less boomy, more open and airy
====
Different strokes for different folks. Compared to my EBS cabs, the ones I've auditioned are boomtoobs.
====
>What dimensions did you use?
What type of material and how thick?
What driver did you use?
What are its specs?
====
Been so long ago I don't remember the exact dims and my notes went up in a house fire, but it was a folded design of square cross section = to the driver's diameter for simplicity's sake.
3/4" marine grade plywood since back then it was the only readily available no-void ply.
Altec 416-8B
Fs 25.1Hz
Vas 749.63L
Qms 7.05
Qes 0.33
Re 6.9ohms
Le 1.5mH
Xmax 3.8mm
Pe 75W
====
>In an AES article on the technology, the concept was described as "ingenious". Instead of stuffing the pipe and losing SPL in order to tame it, a second shorter pipe is used to offest the peaks in the long pipe and vice versa.
====
Written by who, a B*** hack? Of the acoustic 'inventions' by them I'm familiar with, they all are based on decades old concepts. In the early days of Bell Lab's horn compression driver development they tested them with a PWT (plane wave tube, a straight taper pipe), a practice still done today BTW, and experimented with shorter tubes mounted to the rear (open and stuffed), eventually settling on a sealed or small aperiodic rear chamber depending on the intended BW and desired gain. Those guys didn't know squat about all this stuff beyond mechanical and electrical resonant ckts., but best I could tell in my quest to understand horn design they sure did try every combination they could think of. As the inventor Tom Danley has lamented, 'the ancients keep stealing his ideas'.
Anyway, ya'll enjoy them, they're simple to build and great bang/buck, but for the size I prefer to get my bass 'fix' with critically damped EBS or TL, sealed, or corner loaded horn, ergo what I recommend for high SQ.
GM
====
Different strokes for different folks. Compared to my EBS cabs, the ones I've auditioned are boomtoobs.
====
>What dimensions did you use?
What type of material and how thick?
What driver did you use?
What are its specs?
====
Been so long ago I don't remember the exact dims and my notes went up in a house fire, but it was a folded design of square cross section = to the driver's diameter for simplicity's sake.
3/4" marine grade plywood since back then it was the only readily available no-void ply.
Altec 416-8B
Fs 25.1Hz
Vas 749.63L
Qms 7.05
Qes 0.33
Re 6.9ohms
Le 1.5mH
Xmax 3.8mm
Pe 75W
====
>In an AES article on the technology, the concept was described as "ingenious". Instead of stuffing the pipe and losing SPL in order to tame it, a second shorter pipe is used to offest the peaks in the long pipe and vice versa.
====
Written by who, a B*** hack? Of the acoustic 'inventions' by them I'm familiar with, they all are based on decades old concepts. In the early days of Bell Lab's horn compression driver development they tested them with a PWT (plane wave tube, a straight taper pipe), a practice still done today BTW, and experimented with shorter tubes mounted to the rear (open and stuffed), eventually settling on a sealed or small aperiodic rear chamber depending on the intended BW and desired gain. Those guys didn't know squat about all this stuff beyond mechanical and electrical resonant ckts., but best I could tell in my quest to understand horn design they sure did try every combination they could think of. As the inventor Tom Danley has lamented, 'the ancients keep stealing his ideas'.
Anyway, ya'll enjoy them, they're simple to build and great bang/buck, but for the size I prefer to get my bass 'fix' with critically damped EBS or TL, sealed, or corner loaded horn, ergo what I recommend for high SQ.
GM
Hybrid fourdoor said:
good advice, . but too late 😉 i used liquid nails and a piece of sonotube as a coupler between the two tube sections, . will be a bit hard to remove
however, .. the issue of stuffing pushing down on sonotube that you mention is very real, ..and i'm surprised not many mentions this much in TL sonotube practical considerations.
in the final iteration (this monday), i plan to
1. have the driver firing downwards
1. use a piece of cheesecloth on the basket to isolate the driver
Did you go to that Home Depot off of 75 & (Park maybe)? I usually hit the one on 75 & Forrest Lane.
Also Loews carry Sonotubes. Price is similar. There is a Loews at 75 & Spring Creek (North North Plano).
I only mention this because when I lived in Arlington, the Home Depot kept the Sonotubes outside in the Garden area, so they got kinda warped, but Loews kept them inside.
Liquid Nails is great! I use plenty of it...mostly because its strong, but also because its like <$2 for the Heavy Duty tubes
and a tube usually lasts a project.
I once used liquid nail to affix a screen inside a box. You maybe able to do the same thing, just take of the driver and put dabs around the cylinder and fabric against the dabs....its kinda messy on the fingers, but it worked.
Also Loews carry Sonotubes. Price is similar. There is a Loews at 75 & Spring Creek (North North Plano).
I only mention this because when I lived in Arlington, the Home Depot kept the Sonotubes outside in the Garden area, so they got kinda warped, but Loews kept them inside.
Liquid Nails is great! I use plenty of it...mostly because its strong, but also because its like <$2 for the Heavy Duty tubes
and a tube usually lasts a project.I once used liquid nail to affix a screen inside a box. You maybe able to do the same thing, just take of the driver and put dabs around the cylinder and fabric against the dabs....its kinda messy on the fingers, but it worked.
It sure is mentioned in the el-pipe-o post I referenced. Anyway, have you considered strategically tacking it to the sides with hot glue or dabs of liquid nails?
It is not cool to be so harsh and then not back it up.
Also -- you say it is behind a friend's couch. Just measure it.
I contend that a properly designed and built 16HZ to 50HZ dual transmission line subwoofer (since you eschew the term 'Bose Cannon') will stand up against the equivalent AlphaTL or MJK TL stuffed design -- and give greater SPL
Just because MJK has not had the time to sim it does not mean that it is a bad design.
We all know about the endless dribble bashing Bose because he uses lousy drivers and makes shortcuts to his own designs and then eq's the crap out of them to compensate.
The AES article was a university study about the placement of a driver in a tuned pipe -- and had nothing to do with Bose. Its findings were that a driver placed 25% of the way in gave a much smoother frequency response than placed at the end (albeit less low end (of course -- its 25% shorter)). It is available on their website.
I use the term 'Bose Cannon' only because there is an extensive thread elsewhere on this forum so it is a familiar term to others.
My 'dream' alternatives?
If I had loads of cash (and room) I would probably go with IB, multiple drivers, and lots of power -- because its easy and fast.
If I had unlimited time (retired -- will I ever be?), I would go Architectural Horn (18' long, mouth 3' x 8' tractrix) built into the attic.
BTW, sure hope everything is ok from that fire, man.
zobsky said:
It's been my experience that your concerns are well founded.
Woofer Sag Example
This woofer was exposed to a harsh environment, but it's not uncommon to expose items to harsh heat/humidity etc to do accelerated life tests.
Scott Hinson
update ..
thanks for the info on woofer sag,.. i will consider repositioning if this sub becomes a longterm fixture at home.
anyways, .. i hooked up the adire shiva DVC in 4ohm config (+ to + , - to -).
much better bass, . wall shaking at times, ...much better than the mtx woofer.
anyway, .. on some bass notes even at moderate volume, .. i still see the woofer making a noise which can only be described as "thuk" , ... this can't be a 200 watt amp clipping at normal levels. the line is still 8 ft long and the high pass on the crossover is set to 35 - 45 Hz . The line is stuffed with polyfill at around 0.7 lb / cu.ft (0.5 lb / linear foot of 12" tube)
Advice? Is this a case of the woofer being unloaded or is there something else i'm neglecting? to cure this issue, .. do i need more length on the line?
thanks
thanks for the info on woofer sag,.. i will consider repositioning if this sub becomes a longterm fixture at home.
anyways, .. i hooked up the adire shiva DVC in 4ohm config (+ to + , - to -).
much better bass, . wall shaking at times, ...much better than the mtx woofer.
anyway, .. on some bass notes even at moderate volume, .. i still see the woofer making a noise which can only be described as "thuk" , ... this can't be a 200 watt amp clipping at normal levels. the line is still 8 ft long and the high pass on the crossover is set to 35 - 45 Hz . The line is stuffed with polyfill at around 0.7 lb / cu.ft (0.5 lb / linear foot of 12" tube)
Advice? Is this a case of the woofer being unloaded or is there something else i'm neglecting? to cure this issue, .. do i need more length on the line?
thanks
Re: update ..
Sure it could, the amp could be current limiting (ie the amp isn't 200 w into the load). Try wiring the Shiva in series & see if it still does it.
dave
zobsky said:
Sure it could, the amp could be current limiting (ie the amp isn't 200 w into the load). Try wiring the Shiva in series & see if it still does it.
dave
Re: Re: update ..
the plot thickens , ...
not sure if this is strictly relevant to this thread but the mac 2100 i have has autoformers
this is good and bad news
good:
delivers constant power (210 W bridged) into 2,4, 8 ohm or 25V const. (what is 25 Volts constant, BTW)
bad:
no 16 ohm tap (in bridged mode)
not sure what would be ideal in this case
planet10 said:
the plot thickens , ...
not sure if this is strictly relevant to this thread but the mac 2100 i have has autoformers
this is good and bad news
good:
delivers constant power (210 W bridged) into 2,4, 8 ohm or 25V const. (what is 25 Volts constant, BTW)
bad:
no 16 ohm tap (in bridged mode)
not sure what would be ideal in this case
finished !!
bored this weekend, picked up another 4 ft length of sonotube and coupled it to the 8 ft enclosure, .. also stuffed this at the same amount (about 0.6 lb polyfill / cuft), .. better control of the woofer at low bass as opposed to the 8 ft version, .. installed this in the corner so it takes very little real space. the flexy style legs are a boon for adjusting the orientation to maintain the tube absolutely vertical , ..as any slight mismatch in leg length shows up clearly after 12 ft.!!
note: i didn't glue the last 4 ft section to the main assembly (just duct taped it) in order to make disassembly easier in case i ever need to move this monstrosity.
note 2: it's amazing how stable the whole assembly is, .. no fear (at least for now) that it will topple over and bean the occupants of the home
will test for a few weeks and report back, .. i've had the shiva in a sealed box for the last two weeks, ... differences I seem to hear are a smoother bass response and somwaht less constrained sound (less boxy??)
thanks to all the contributors to this thread for their help and support. this is your sub, as much as mine.
any other suggestions / advice, ... please post
bored this weekend, picked up another 4 ft length of sonotube and coupled it to the 8 ft enclosure, .. also stuffed this at the same amount (about 0.6 lb polyfill / cuft), .. better control of the woofer at low bass as opposed to the 8 ft version, .. installed this in the corner so it takes very little real space. the flexy style legs are a boon for adjusting the orientation to maintain the tube absolutely vertical , ..as any slight mismatch in leg length shows up clearly after 12 ft.!!
note: i didn't glue the last 4 ft section to the main assembly (just duct taped it) in order to make disassembly easier in case i ever need to move this monstrosity.
note 2: it's amazing how stable the whole assembly is, .. no fear (at least for now) that it will topple over and bean the occupants of the home
will test for a few weeks and report back, .. i've had the shiva in a sealed box for the last two weeks, ... differences I seem to hear are a smoother bass response and somwaht less constrained sound (less boxy??)
thanks to all the contributors to this thread for their help and support. this is your sub, as much as mine.
any other suggestions / advice, ... please post
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