Get ready. That is where the addiction turned on me and no rehabilitation in sight, lol. Trust anything written by MMJ and any designs. He will totally dismiss most of those as ‘inferior’ now-a days, but only because he’s created even more uniquely potent things since.... there’s lots of great ideas in that!!!
I started last summer basically making MLTLs with a brief combined exit where the motor side (direct radiator in this case) was in a rear chamber of no substantial length. After awhile that morphed into an expanding pathway much like transflex might illustrate. After that it’s a struggle between a tapped pipe or a ROAR/Paraflex depending on the Bl^2/Re.... I found MMJ by luck and he tossed me in his apprentice program, lol! A paraflex is brutal on the cone and it takes real motor force to push it around sufficiently to even work within a paraflex. Or a similar design without the short series exit I posted above. I have both vents set at their radius from a centerline between them if not briefly as one in the last segment of the Taped entry/exit. These are two 1/4 paths interacting which cane from a source 180 outta phase for Fb at the cone, from each side if it, then put through a qw path (or argueabky heimholtz in the case of done HF sections dimensions. to be zero at the exit or where they combine just outside the box...scocery and black magic while nearly kicking the deputy sheriff in the nuts when he cited you for trying to break the IRon law! Haa!
Here’s the isobaric. I think I used every piece of scrap wood around during covid to build a bunch of busywork designs while on ‘vacation’.
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I really enjoy reading about all this stuff but don't have room or indeed a room for all of the woodworking tools involved, like table saws etc.
So it's routing circles and PVC pipes for me until I move to somewhere with a barn!
So it's routing circles and PVC pipes for me until I move to somewhere with a barn!
Circular saw with a clamped straight edge is more than adequate!, and the router/straight edges with flush trim bit fix all jacked up cuts to match the other panels anyhow👍🏻
Current paraflex ready to be replaced with the large expanding path but similar version to exploit dB gained for volume used to its diminished return state for what I can struggle to use (400 liters) on the back patio or in a vehicle( lord help me)
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The isobaric looks like a monster.
Thanks for the tip on the circ saw; I have a baby bench saw that is simply a POS. I've never managed a straight cut with it yet.
Thanks for the tip on the circ saw; I have a baby bench saw that is simply a POS. I've never managed a straight cut with it yet.
Another paraflex I built with an alternate exit experiment. I’m totally into this design and the sound. Only left wanting a lower Fb, and that’s just an excuse to build more stuff as the isobaric already resolved that. So BIG and very FLH ish with Rez chamber is the idea now. And I’ve made enough sins to go OCD, it’s time to make the cut list(after I complete a couple things for 2.1 family /friend gifts I committed to for fun and at the happiness of ‘gift’ to others....
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I do a lot on the circular since I can get out in the open and not breath the dust so much! I just used table saw If bad weather or crosscut sled individual small panels
I need to measure isobaric so I can share my findings. I also tried to measure the TS parameters as isobaric but attaching the needed weight for Vas and MMd was not cooperating whatever I did (motor side of the drivers had no decent points for this essentially. And I dented an aluminum cone slightly trying pinching magnets inside and out...
Yep, that's a biggun.
Guess if it goes on the patio, it ain't even good for placing jars of beer as they'd foam up and vibrate off.
You must have understanding neighbours, or perhaps ones you hate?
Iffn I decide to go to the local hardware store and pick up an appropriate "circular saw with a clamped straight edge", are there any you'd recommend?
We can get most any brand down here nowadays.
Also, if I decide on a woody box project I guess I should begin with a simple TL that would suit my spare RSS390HO-4 15" Reference HO Subwoofer 4 Ohm?
Anything spring to mind offhand?
Resonant Frequency (Fs)21.5 Hz
DC Resistance (Re)3.2 ohms
Voice Coil Inductance (Le)1.79 mH
Mechanical Q (Qms)3.69
Electromagnetic Q (Qes)0.35
Total Q (Qts)0.32
Compliance Equivalent Volume (Vas)5.93 ft.³
Mechanical Compliance of Suspension (Cms)0.17 mm/N
BL Product (BL)19.8 Tm
Diaphragm Mass Inc. Airload (Mms)319g
Maximum Linear Excursion (Xmax)12 mm
Surface Area of Cone (Sd)829.6 cm²
Guess if it goes on the patio, it ain't even good for placing jars of beer as they'd foam up and vibrate off.
You must have understanding neighbours, or perhaps ones you hate?
Iffn I decide to go to the local hardware store and pick up an appropriate "circular saw with a clamped straight edge", are there any you'd recommend?
We can get most any brand down here nowadays.
Also, if I decide on a woody box project I guess I should begin with a simple TL that would suit my spare RSS390HO-4 15" Reference HO Subwoofer 4 Ohm?
Anything spring to mind offhand?
Resonant Frequency (Fs)21.5 Hz
DC Resistance (Re)3.2 ohms
Voice Coil Inductance (Le)1.79 mH
Mechanical Q (Qms)3.69
Electromagnetic Q (Qes)0.35
Total Q (Qts)0.32
Compliance Equivalent Volume (Vas)5.93 ft.³
Mechanical Compliance of Suspension (Cms)0.17 mm/N
BL Product (BL)19.8 Tm
Diaphragm Mass Inc. Airload (Mms)319g
Maximum Linear Excursion (Xmax)12 mm
Surface Area of Cone (Sd)829.6 cm²
This is what I’m clogging up your nice thread for though and picking Greg’s big brain for any ideas or safe zones to stick with in designing/building this conjecture system of multiple actions and reactions from both ends of the driver and back again as pressure or velocity and node /antinode... etc, etc (hurts my head , lol).
I can juggle this around and get 31/32 hz and that sort of response in a sim not exceeding the Bl assumed close enough to be used at the Xmax figure.
I can juggle this around and get 31/32 hz and that sort of response in a sim not exceeding the Bl assumed close enough to be used at the Xmax figure.
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Yes! We can use Brian Steele’s Standard straight TL math and maybe let Greg have a looksee and an approval or suggestion if he feels it’s needed👍🏻
Here’s a bit of gold for your kind words and friendly sharing of your thread🍻
Here’s a bit of gold for your kind words and friendly sharing of your thread🍻
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I need to add a small area to fit the big 15” driver. Since this is end fired I need to stick to the very end as any offset(even the radius of the driver basket flange) creates things only seen in a sim otherwise. So I bust down the 829 Sd into a diameter or basically give a 16x16 square inch shape room to fit with excursion
Or the surround shape and bulging parts on stroke clearance( a couple inches maybe, doesn’t need much of any but it’s gotta be done to fit this at the least sideways touching the very end (and slightly inaccurate for the amount of that offset btw if not end fired). We are motor side out essentially, but if you use the 16” or so and the 7-8” motor depth you’re way past 541 cm2.... this can be creatively fixed in several ways.. but whatever works to build accurate is the idea...
Or the surround shape and bulging parts on stroke clearance( a couple inches maybe, doesn’t need much of any but it’s gotta be done to fit this at the least sideways touching the very end (and slightly inaccurate for the amount of that offset btw if not end fired). We are motor side out essentially, but if you use the 16” or so and the 7-8” motor depth you’re way past 541 cm2.... this can be creatively fixed in several ways.. but whatever works to build accurate is the idea...
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Here’s what we get: and red is with some stuffing added to the sim. Fs is 22.3hz, you can mess with the line shape and its length a bit and damp this as you prefer����. But for a plain no offset driver TL this is a great start to an easily tuned to taste subwoofer
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Circular saw brand might be makita for great and expensive. Or ryobi for decent and economical? I have a bit of both and even some classic SEARs ‘craftsmen’ brand from my father
Btw, you have impressive choices in drivers! I take my hat off to you ��! I’m a Dayton RS/RSS fan, listening to rs100s as I type this
Btw, you have impressive choices in drivers! I take my hat off to you ��! I’m a Dayton RS/RSS fan, listening to rs100s as I type this
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So something along the lines of his Boxplan TL1 or TL2 designs?
The Subwoofer DIY Page - Horn Folding
But they don't look square shaped like the 16x16 inch you suggest.
Or am I missing something!
Will check out Ryobi circular saw. I have plenty of their stuff and their power tools just seem to keep on keeping on for me.
Thanks again for taking the time to do the sim. Appreciate it.
Peter
The Subwoofer DIY Page - Horn Folding
But they don't look square shaped like the 16x16 inch you suggest.
Or am I missing something!
Will check out Ryobi circular saw. I have plenty of their stuff and their power tools just seem to keep on keeping on for me.
Thanks again for taking the time to do the sim. Appreciate it.
Peter
Thanks Peter.
You can fit the driver into the line a lot ways. Motor depths and/or diameter are needed to sim it all accurately is all... Brian’s math equation estimators and workbooks seem to be good stuff from what I’ve seen and used myself in the past 🙂
You can fit the driver into the line a lot ways. Motor depths and/or diameter are needed to sim it all accurately is all... Brian’s math equation estimators and workbooks seem to be good stuff from what I’ve seen and used myself in the past 🙂