MIGHTY DUB PASS
Printed From: Speakerplans.com
Category: Plans
Forum Name: Other plans
Forum Description: Discussion / Questions about all the other plans
URL: https://forum.speakerplans.com/forum_posts.asp?TID=12351
Printed Date: 26 March 2026 at 10:04pm
Software Version: Web Wiz Forums 12.08 - https://www.webwizforums.com
Topic: MIGHTY DUB PASS
Posted By: jsg mashed
Subject: MIGHTY DUB PASS
Date Posted: 23 October 2007 at 9:31pm
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M I G H T Y D U B P A S S MIGHTY DUB PASS has been designed. I will fill in more details as I get time, but here's the low-down: MIGHTY DUB PASS is designed for use in singles or multiples. MIGHTY DUB PASS operates from 30Hz to 110Hz. MIGHTY DUB PASS shows a half-space sensitivity of 101dB standard conditions in half space (but my tool gives more conservative results than most). MIGHTY DUB PASS is designed for Void V18-1200. It's probably good with RCF L18P300 and maybe some other drivers - I'll check later. Not suitable for PD1850 or V18-1000 unfortunately. I will supply diagrams later. To build, make a cuboid outer shell 1220mm high by 636mm wide by 750mm deep external (just slightly smaller than Rog's super scooper). Use 18mm ply and brace well. Make a double-thickness (36mm) shelf panel to mount horizontally inside the shell. Cut a hole to mount the driver centred 275mm from the back of the shell. Build a cylindrical tube structure out of layered bendy wood internal diameter 500mm, length 300mm, thickness 25mm and attach to the underside of the shelf on the same centre as the driver (driver will sit on top of shelf, and cone faces through the cylinder). Plug the cylinder with a circular double thickness panel 500mm dia. Note that the cyclinder should contact the back of the outer shell - glue here for reinforcement. The plug panel should contain a 300mm diameter hole at its centre for a reflex port. Cut two additional port holes 175mm dia in the space available at the front of the shelf panel. The shelf panel should be mounted to leave 370mm clearance between top of shelf and bottom of shell top panel. Make a hole in the front panel located 200mm from the bottom of the cabinet to a diameter of 325mm (this dimension might change) for the final output port. Port lengths have yet to be specified; they should be determined to achieve cabinet resonaces (low Z) at 28.5Hz, 57Hz and 101Hz. Driver resonances (high Z) should be at 15Hz, 39.5Hz, 80Hz and 119Hz. I will supply the actual lengths when I have determined them. MIGHTY DUB PASS has been created, at least in theory. Let me know if you want to build one, and I'll help with the port length determination (which requires a built prototype). Edit: slight tweaks to let the A and B ports be bigger (so they never exceed 5% speed of sound at 1400 watts, xover <= 100Hz). A port assumed half in A and half in C. B port assumed mostly in B (bottom of port level with bottom of A cavity). C port all in C. ------------- ...because Good is Dumb. |
Replies:
Posted By: Heathrow_B_line
Date Posted: 23 October 2007 at 9:44pm
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I think a drawing would be really helpful my friend as i am abit confused... even a rough hand sketch would clear things up abit
Also could we have the winisd input data if you have it
------------- Produce a killer sound. Take no prisoners. |
Posted By: Jhodas
Date Posted: 23 October 2007 at 10:25pm
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You're down on scoops already my friend. most get between 102-105dB sensitivity within usable bandwidth. (in half space) Just how conservative is your software? ------------- Until the Lions have their own historians, tales of hunting will always glorify the hunter. |
Posted By: LostGrayCat
Date Posted: 23 October 2007 at 10:40pm
| So this is all in your head, not even on paper? |
Posted By: simo69
Date Posted: 23 October 2007 at 10:44pm
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Has this been built, tried and tested?
I am very interested as I run 8 X TSE218's, TMS4's, TSM3's etc, and need some serious sub below 40hz, what do you recomend?
We have recently bought a pair of G-Subs off Robbo to play with, just need to get the to get the phase right with the TSE218's.
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Posted By: mykey
Date Posted: 24 October 2007 at 10:12am
I just did all of the above and ended up with a DOG kennel  ------------- ......just all them hanging there like giant bananas. |
Posted By: jsg mashed
Date Posted: 24 October 2007 at 10:16am
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Hi all Thanks for taking an interest MIGHTY DUB PASS has been modelled using my proporietary software - which has also been used to model various similar subs which have been tested and check out. Diagrams to follow. MIGHTY DUB PASS is an 8th order design - I don't think WinISD even supports that...? As regards sensistivity, remember that a scoop's frequency response gets messed up when used in singles, and the bottom end goes away, leaving a response to perhaps 40Hz -3dB (=pathetic). Only when combined in groups do you even get close to the specified response. MIGHTY DUB PASS gets 106dB in mutliples of 4, and covers 30Hz to 110Hz -3dB with about 1dB ripple in-band. Incidentally, this is one of the subtler problems with introducing new technology into an established domain. People (rightly) want to know the catches and what-ifs of the new ttech, but sometimes they have to be remineded that the *current* tech has it's own drawbacks too. ------------- ...because Good is Dumb. |
Posted By: mykey
Date Posted: 24 October 2007 at 10:26am
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A rough sketch would be cool?
I have a picture in my head now a box similar to the giant JBL tripple chamber band pass bin, anything like that?
[kicks dog back in kennel] ------------- ......just all them hanging there like giant bananas. |
Posted By: adambomb
Date Posted: 24 October 2007 at 11:28am
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I found this on 8th order BP : http://www.geocities.com/f4ier/speaker.htm - http://www.geocities.com/f4ier/speaker.htm
not you is it JSG?
and heres a picutre of an 8th order BP :  ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: levyte357
Date Posted: 24 October 2007 at 11:37am
Please let us know how we can expedite the completion of your DUB PASS endeavours. So that the inaccuracies of the above statement, can be addressed at the earliest possible convenience. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
jsg mashed wrote:Posted By: jsg mashed
Date Posted: 24 October 2007 at 11:40am
They look similar, but there are differences - in fact MIGHTY DUB PASS is more advanced than this old JBL design.
The JBL triple-chamber cab is really just a dual-chamber (parallel 6th order) because the outer two chambers are identical and there's a driver in each. Since each outer chamber does the same thing, merging them into one wouldn't change the behaviour of the system.
MIGHTY DUB PASS is designed for one driver. There are 3 chambers, but here each chamber plays a different role, which is why it's an 8th order design. Chamber "A" is the cylinder in front of the driver (it is cylindrical to ensure symmetrical loading on the driver cone and avoid cone failure). Chamber B is the top quarter of the cabinet behind the driver, and chamber "C" is the large space below A and B.
As far as porting goes, chambers A and B are both ported into chamber C and then C is ported to the outside. The C port is the only port that goes outside, and it has to be very big to move all that air. In fact I recommend a grille of some sort otherwise Fido could get a nasty surprise, but I think you need more percentage open area than a regular punched metal grille provides. More on that later.
------------- ...because Good is Dumb. |
Posted By: jsg mashed
Date Posted: 24 October 2007 at 11:47am
That's not my site, but the diagram is correct for 8th order bandpass. Flip the driver over, make the middle chamber cylindrical (I only did this to reduce uneven cone loading) make the ports bigger and tune them correctly and you have MIGHTY DUB PASS. ------------- ...because Good is Dumb. |
Posted By: mykey
Date Posted: 24 October 2007 at 11:48am
Niiiiiice!
sound a bit like the Stacys X
edit.
How did you beat me to that post Adam
 wasn't clapping the drawing was clapping the description
seen this idea somewhere before actually, think it come from car audio
still acnt believe it will be a scoop EATER or BEATER ------------- ......just all them hanging there like giant bananas. |
Posted By: simo69
Date Posted: 24 October 2007 at 11:56am
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This sounds simliar to the NEXO LS500 - design only - using 3 chambers. I have a drawing of the LS500
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Posted By: jsg mashed
Date Posted: 24 October 2007 at 12:04pm
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Hi well Stasys X combines resonant (bandpass-style) and horn techniques. I don't know exactly what goes on at the back of the cabinet, but ultimately it splits its cabinet volume between elements that provide "kick" and elements that provide low frequency bass. So I'd say it's an all-rounder bass cabinet.
MIGHTY DUB PASS is focussed purely on low-frequency bass. If you wanted to use it for techno/hard house etc you'd need to combine it with other bass cabinets.
That Nexo thing looks like a parallel 6th so yes, MIGHTY DUB PASS has more chambers. Plus, that Nexo is ugly.
Edit: mykey, as far as SCOOPS go, the clock is now ticking. You know... the solemn clock. The solemn clock that counts the days until the grim one with the scythe comes to reap all SCOOPS.
------------- ...because Good is Dumb. |
Posted By: adambomb
Date Posted: 24 October 2007 at 12:15pm
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JSG... can you give me the box volumes... trying to use that free sim in the geosh*ties link. ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: mykey
Date Posted: 24 October 2007 at 12:25pm
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Edit: mykey, as far as SCOOPS go, the clock is now ticking. You know... the solemn clock. The solemn clock that counts the days until the grim one with the scythe comes to reap all SCOOPS.
 Then shouldn't you call it... "THE MIGHTY GRIM REAPER"?
 ------------- ......just all them hanging there like giant bananas. |
Posted By: jsg mashed
Date Posted: 24 October 2007 at 12:28pm
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Hi
A=66l, B=136l, C=238l. As for tunings, just tweak until you get the impedance highs/lows I listed earlier. But I once tried to use that program and couldn't get it to work. Perhaps you'll have more luck.
Also, all programs give different results, so don't be disappointed if the results don't look that good. The important thing to remember is that I've built and used similar designs based on my design software, so it works for this kind of cab (high power, high efficency 18-inch driver).
------------- ...because Good is Dumb. |
Posted By: adambomb
Date Posted: 24 October 2007 at 12:36pm
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hmm.. playing with that sim prog.. the response looks like a simlulated X1 response (peaks eather side, dip int eh middle...
I bet itts the same deal as the X1.. models lumpy.. plays flat (er).
Driver excursion looks very very good tho! (looks like it could take a whole heap of power). ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: jsg mashed
Date Posted: 24 October 2007 at 12:47pm
Wow you got it to work!
 What OS you running?
NEway, I don't see the dip in the centre in my models (in fact I take care to avoid that kind of dip). I'll try and compare the two program's predictions when I get a chance.
I don't want to cast aspersions but the thing is the formulas for 8th order are furiously complicated. It took me 10 A4 pages of working to derive them by hand, and what's the likelyhood of an error in the working? High. So I wrote my SW to effectively do the derivation itself, kind of like Akabak. This way I can confirm each part of the program's algorthm in simpler cabs that are easier to double-check and so have more confidence in the results for 8th order.
Then again maybe the author of the other program did that too.
------------- ...because Good is Dumb. |
Posted By: adambomb
Date Posted: 24 October 2007 at 12:53pm
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XP SP2... ran perfect straight away. ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: jsg mashed
Date Posted: 24 October 2007 at 2:27pm
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adambomb:
I've got it looking pretty close in Subwoofer Simulator. 8th order is tricky with its tunings - the cavities are all coupled and "pull" each other's resonances. So the actual resonances shown in the plot don't correspond exactly with the frequencies you enter in the "boxes" section. After a little fiddling, I get my specified cab resonaces (lows) when I use 33, 60 and 94Hz in the "Fb" boxes.
Driver resonances (highs) still don't match exactly, probably due to a disagreement between my S/W and Subwoofer Simulator about pressure or density of air (both of which vary all the time anyway).
Personally, I find that the "pulling" issue (which affect series 6 and 8 but not reflex, parallel 6 or 4) is a big source of confusion. I prefer to describe ports via inertience.
------------- ...because Good is Dumb. |
Posted By: login4
Date Posted: 24 October 2007 at 5:12pm
all very exiting, even more so when the plans are released... ------------- CELTIC SUBSONIC SOUND SYSTEMS |
Posted By: twinypaul
Date Posted: 24 October 2007 at 7:38pm
that it i will have to release my armageddon sub 36 inchs of thigh slapping bass ------------- paul |
Posted By: jsg mashed
Date Posted: 25 October 2007 at 5:56pm
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Just done a few sums, and it looks like MIGHTY DUB PASS might also work OK with PD 2150. That would be most interesting...
But in the interests of fairness, soundoffs against soon-to-be-obsolete SCCOPs will still use the V18-1200 as I originally specified.
------------- ...because Good is Dumb. |
Posted By: levyte357
Date Posted: 25 October 2007 at 6:00pm
Right... So when this cab come out, all scoop users will switch to this, and stop using scoops. Must remember that. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: jsg mashed
Date Posted: 25 October 2007 at 6:02pm
Every single one.
------------- ...because Good is Dumb. |
Posted By: jbl_man
Date Posted: 25 October 2007 at 6:44pm
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errr...is this all speculation,or has anyone actually built and tested one of these yet?...would be interesting to put it up against a 4520.......especially one of Tony`s. ------------- Be seeing you. |
Posted By: adambomb
Date Posted: 25 October 2007 at 7:14pm
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Come on Come on... Final plans wanted!!!
JBL... it's complete fantasy / ideas at the moment.. but I'm hooked on the idea....
Mind you I do like esoteric / obscure box designs for no reason other than that I want to understand how they work... call me wierd. ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: jsg mashed
Date Posted: 25 October 2007 at 7:50pm
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Hi At present MIGHTY DUB PASS is a free cabinet plan in text form - which seems in tune with the spirit of this site (geddit?  ). The next thing to do is to draw the plans and then build a prototype, tune the ports and off we go.At this time MIGHTY DUB PASS has been modelled by two different people using two different software tools. It's also similar in a lot of ways to my last design, which has been built, tested and deployed at parties with great success (single cabinet, half the size of MIGHTY DUB PASS served a party of 100 or so outdoors all night without ever straining or needing to clip the amp). So MIGHTY DUB PASS is a pretty serious contender - not just pulled out of anyone's rear port, so to speak. I just have to make sure not to screw up the technical drawing by hurrying too much! It will probably appear over the weekend. ------------- ...because Good is Dumb. |
Posted By: adambomb
Date Posted: 25 October 2007 at 8:12pm
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COOL BEANS! ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: Disco Stu
Date Posted: 25 October 2007 at 10:04pm
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I am interested in this cab half the size of the DUBPASS, what drivers was it for?
Have you got any plans for that one?
Stu ------------- All you need to know is: Sensitivity + Power Handling - Power Compression = Max Output My acts: www.myspace.com/thebowiexperience www.myspace.com/scheisseelektronisches |
Posted By: jsg mashed
Date Posted: 25 October 2007 at 10:26pm
Hi Stu Well that cabinet is called bandpass bertha and it uses a single PD1850. It's more for general purpose use so the response is a little different. I have the cavity dimensions but I'll have to open up the box to measure the ports (should have done that after I tuned it, oh well). ------------- ...because Good is Dumb. |
Posted By: jsg mashed
Date Posted: 26 October 2007 at 7:49pm
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I've been listening to some dubstep (at dubstep.fm) and looking at it on speccy analyser. Seems there's more time-domain information than regular dub music - partly in the beat and also in the way they "chop up" the bass lines using synth effects. So I've tweaked the MIGHTY DUB PASS design to tighten up the group delay curve. It now stays between 10.0 and 12.0ms down to 50Hz (then rises like all bass cabinets do). This will be enough to basically eliminate the flabby sound often associated with bandpasses. It also helps with integrating with kick bins because you can set the delays for 11ms. Upper f3 drops to 105Hz and sensitivity actually rises to 102dB which is nice. Schematics soon! ------------- ...because Good is Dumb. |
Posted By: Mark James
Date Posted: 26 October 2007 at 8:31pm
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how low do they play??? [the last box you described] ------------- insert silly sentence here |
Posted By: bill-77
Date Posted: 26 October 2007 at 9:03pm
hi just sold my wembley b-lines and in need of some scoops or similiar...these all mighty dub subs sound very promising.whens the pictures of the proto type being released ?  or maybe the plans!!!!
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Posted By: mykey
Date Posted: 27 October 2007 at 4:13am
If you liked the sound surley thats good enough?
What drivers you left with? ------------- ......just all them hanging there like giant bananas. |
Posted By: mykey
Date Posted: 27 October 2007 at 4:19am
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what did one gay cowboy say to another gay cowboy? you uuup? yyyyep ------------- ......just all them hanging there like giant bananas. |
Posted By: mykey
Date Posted: 27 October 2007 at 4:44am
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I do like the way this reads actually
JSG quote
The output port if MIGHTY DUB PASS, at 13 inches diameter, will excurse over 11 inches peak to peak.
My current sub has a 11 inch output port that excurses 8 inches and it's quite freaky what it does to the air when you generate that much bass at one position. And that output doesn't include any of that you-blow-I-suck cancellation or any puffy, unsucessful attemts to play below f3. Just bass pressure in its purest, unstrained, undistorted form.
Anyway, I'm going to abandon this thread now so that it can return to a SCOOPS discussion. Please join us in the MIGHTY DUB PASS thread in the "Other Plans" forum.
 unless JSG is Rog on some magic mountain mushrooms
------------- ......just all them hanging there like giant bananas. |
Posted By: jsg mashed
Date Posted: 27 October 2007 at 8:39pm
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MIGHTY DUB PASS schematics now at http://www.bestsharing.com/files/PVr0LPk355268/dubpass_noport.pdf.html - http://www.bestsharing.com/files/PVr0LPk355268/dubpass_noport.pdf.html I haven't put in port lengths yet because these require a built prototype. Enjoy! Edit: it's missing overall height. That's 1220mm. Edit: Ive removed this file because now there's a revision 2 (MIGHT DUB PASS the director's cut) . See later in this thread for the link. ------------- ...because Good is Dumb. |
Posted By: Heathrow_B_line
Date Posted: 27 October 2007 at 8:49pm
 ------------- Produce a killer sound. Take no prisoners. |
Posted By: bill-77
Date Posted: 28 October 2007 at 1:38am
| hi mykey sold the 2820,s as they didnt meet my exspectations..and yes it was due to your recommendations...being into reggae/dub/dance hall they didnt give the sound i was after. i thought why waste my investment and resources in to these cabs when i,m not satisfied.The x2 pd1850,s i purchased sound nice in the scoop box,s i brought of my friend...now i,m thinking of the v-1200,s x2 in short man scoops.... ,levy,s very happy with the way his 4 sound ...the test resulsts carried out with the various drivers and scoops proved it all....does any body know how much the shortman scoops cost ? pm me ....i sent shortman a pm but he seems to be very buisy and hasnt come on forum for a while now regards bill peace.... |
Posted By: jsg mashed
Date Posted: 28 October 2007 at 2:49am
HBL - thank you! bill-77 - perhaps it would be better if you contacted mykey directly ------------- ...because Good is Dumb. |
Posted By: mykey
Date Posted: 28 October 2007 at 5:13am
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JSG
Very nice of you, I'll thank you if no one else will, thank you very much for putting your self out. ------------- ......just all them hanging there like giant bananas. |
Posted By: mykey
Date Posted: 28 October 2007 at 7:22am
------------- ......just all them hanging there like giant bananas. |
Posted By: bill-77
Date Posted: 28 October 2007 at 3:49pm
would you know or any body where his work shop is located and how i will be able to contact him maybe a mobile number or buissness number pm me please regards bill peace
|
Posted By: Joe Grime
Date Posted: 28 October 2007 at 4:27pm
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SOUND BARRIER Loudspeaker Cabinet Design & Construction (Box Builder) Contact:
Steve Allen (a.k.a Shortman) (Based in W/Shop: 0207 252 6721 mailto:shortmans1@yahoo.co.uk - |
Posted By: jsg mashed
Date Posted: 28 October 2007 at 5:37pm
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Another missing dimension on my plan is the internal height of the upper (B) chamber. It's 406mm. Now it just needs someone bold enough to step up to the (dub) plate and build one. Or several... ------------- ...because Good is Dumb. |
Posted By: TONY.A.S.S.
Date Posted: 28 October 2007 at 5:47pm
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Do these cabs exist and if so How many have you built? ------------- http://www.facebook.com/tony.rossell.3" rel="nofollow - http://www.facebook.com/tony.rossell.3 |
Posted By: LostGrayCat
Date Posted: 28 October 2007 at 6:18pm
I think this kids blowing smoke. |
Posted By: jsg mashed
Date Posted: 28 October 2007 at 7:14pm
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Hi Tony I haven't built any MIGHTY DUB PASS. But it's been modelled by seperate people with seperate modelling SW. I've also already built a slightly smaller sub based on the same design and run it at parties, with great sucess. So I know the approach works. I was wondering if you would like the grand honour of being the first to posess MIGHTY DUB PASS... To the blowing smoke guy - you're welcome to come over and see my current sub, which really exists and really works. Otherwise: bite me. ------------- ...because Good is Dumb. |
Posted By: jsg mashed
Date Posted: 28 October 2007 at 7:25pm
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MIGHTY DUB PASS REVISION TWO So I've done a revised plan that fills in some missing information and is generally a bit tidier. Also tweaked the design to get group delay even tighter (stays in 1.5ms window from 47Hz to 110Hz - you won't realise you're listening to a bandpass). Here ya go http://www.bestsharing.com/files/rhy8Er355875/dubpass_noport_rev2.pdf.html - http://www.bestsharing.com/files/rhy8Er355875/dubpass_noport_rev2.pdf.html ------------- ...because Good is Dumb. |
Posted By: LostGrayCat
Date Posted: 28 October 2007 at 7:27pm
| Well, till you really build the "MIGHTY DUB PASS", you can bite yourself. |
Posted By: jsg mashed
Date Posted: 28 October 2007 at 7:47pm
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LOSTGREYCAT: I don't have the space to build it, or store it, or transport it. I offered to design MIGHTY DUB PASS and that is what I have done. I have explained repeatedly that MIGHTY DUB PASS would be a design, and that I was not going to build the prototype. It's a free design, so if anyone fancies building one they are most welcome and I'll be happy to provide support. If you don't get some aspect of MIGHTY DUB PASS just ask and I'll explain it to you. Until then, you can bite the Queen of Sheba. ------------- ...because Good is Dumb. |
Posted By: LostGrayCat
Date Posted: 28 October 2007 at 7:58pm
| Like I said, he's blowing smoke. |
Posted By: jsg mashed
Date Posted: 28 October 2007 at 8:06pm
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LOSTGREYCAT fails his reading comprehension test for reading an entire thread and not comprehending a single thing that has been said. ------------- ...because Good is Dumb. |
Posted By: LostGrayCat
Date Posted: 28 October 2007 at 8:08pm
This coming from a twit that can't spell my nic correctly. 
|
Posted By: jsg mashed
Date Posted: 28 October 2007 at 8:18pm
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LOSTGREYCAT, I don't think the spelling of your "nic" as you call it is particularly important. It isn't even your real name. What is your real name by the way? I publish my contact details while you hide behind some unimginative "nic". And yet you're the one who repeatedly make the "blowing smoke" accusations. How ironic. I bet you're one of those "hanger on" types who never contributes anything to the sound industry but instead just tries to get credibility by association. If you had any real skills you'd have a job worth mentioning on your public profiile. Pathetic. ------------- ...because Good is Dumb. |
Posted By: LostGrayCat
Date Posted: 28 October 2007 at 8:28pm
Occupation: Software Engineer
Yes you are. Put your money where your mouth is and build the cabinet that's going to replace the Scoop.  |
Posted By: jsg mashed
Date Posted: 28 October 2007 at 8:33pm
OK mr NoName, this is getting stupid. I pledged to design the cabinet that's what I have done. It's so simple. Why can't you understand? What happened your brain? ------------- ...because Good is Dumb. |
Posted By: jsg mashed
Date Posted: 28 October 2007 at 8:52pm
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Apologies to everyone for that - I think the nasty man who hides behind anonymity whilst trying to discredit others by misrepresenting their claims has gone now. If any box builders would like to participate in the future (instead of blowing smoke at it), please get in touch. The port tuning is pretty straightforward, and you're welcome to have a play with an existing cab I have that uses the same kind of design. Oh, and I posted a second revision of the design - see http://www.bestsharing.com/files/rhy8Er355875/dubpass_noport_rev2.pdf.html - http://www.bestsharing.com/files/rhy8Er355875/dubpass_noport_rev2.pdf.html ------------- ...because Good is Dumb. |
Posted By: ceharden
Date Posted: 28 October 2007 at 8:57pm
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Oh dear.... I would like to partly side with Mr LostGrayCat in that while jsg mashed has produced an interesting concept for a cab it is not a finished design. Having designed on paper and built many different cabs over the past few years, no design is ever finished and ready at the end of the drawing stage. Transferring a concept into a buildable cabinet and ironing out the finer points of the design is (in my opinion) the most difficult part. It is entirely possible to take a design which works well on paper, build it and find that it is nothing like you imagined. So unfortunately, until someone has built and tested a prototype it is unlikely to be taken too seriously. |
Posted By: jsg mashed
Date Posted: 28 October 2007 at 9:18pm
Even doing the conceptual design is quite a challenge with 8th order bandpasses. But yes, you have a point. If you look at the plans you'll see that I've considered manufacturability in some detail. Many of the problems that come up are the same from one sub to the next, so over time it gets easier to predict these. I have left out bracing - I've got it worked out in my head, but it would make the plans much more complex, and any competant constructor can probably do the bracing just as well their way.
I also left out the port lengths from the diagram. This is because I've found that with bandpasses the actual port tuning is by far the biggest reason subs don't come out as expected. This is because any obstruction near a port adds extra inertience (increasing the so-called end correction). The extent of this depends on the exact details of the cabinet and unless you want to get into finite element modelling, you can't predict that. So I always work on the assumption that final port lengths will be determined by experiment. Of course there are mistakes we can make with eg extreme dimensions but I've made those already and know about them. There are also issues with degraded response if the cabinet is badly assembled, but that doesn't invalidate the design. So I'm pretty confident in this process. And for the 365088798589763965th time I'll repeat myself and say that MIGHTY DUB PASS really isn't much different to a sub I have in the other room as I type this and which I will shortly enjoy the LFE channel of King Kong through.
As long as everyone knows it hasn't been built yet, and that that was the plan all along, I really don't mind because it's free anyway. ------------- ...because Good is Dumb. |
Posted By: VECTORDJ
Date Posted: 28 October 2007 at 9:23pm
| My first feeling about this design is this is going to be a one note boom box. But....it might work......on something so out of the main stream it would be nice if the designer built one and tested it to prove his ideas before posting it. It takes a brave man to go where others will not tread. VECTORDJ |
Posted By: jsg mashed
Date Posted: 28 October 2007 at 9:33pm
I understand what you mean about the one-note thing. The BOSE 302 did a lot of harm to the reputation of bandpasses and even some of the bandpass efforts by more respectible companies were questionable. There were also a lot of "generic" any-driver deisgns going around eg in the old Eminence book. Some sorts of speaker cab can accept a wide range of drivers unmodified. Some need slight mods. But bandpasses are fussy and can only take the driver it was designed for and very similar ones. Then bandpasses got associated with car audio and crappy 4th order designs with perspex panels. This virtually killed their reputation off completely. I've been sucessfully avoiding one-note bass for years now. You have to - Set bandwidth >1.5 octaves and keep group delay variations down - Make sure the bandwidth includes all the frequencies you'll actually play through it - Tune the actual cab with impedence measurement gear to make sure you've got what you designed. ------------- ...because Good is Dumb. |
Posted By: LostGrayCat
Date Posted: 28 October 2007 at 9:50pm
| Weren't you going to watch TV or something usefull? |
Posted By: Jhodas
Date Posted: 29 October 2007 at 12:05am
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jsg, I've gone from skeptical to curious. I maintain that the claim this box will replace ALL scoops is bold. However, that doesn't detract from what could be a very good design. I look forward to hearing it. ------------- Until the Lions have their own historians, tales of hunting will always glorify the hunter. |
Posted By: login4
Date Posted: 29 October 2007 at 1:22am
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ye im sure it wont be too long till someone's board one weekend and fancies making one, should be an easy build, it would be a little easier if chamber 'A' was a simple box rather than a cylinder and maybe port 'B' could be one long self port type thing down the one internal side. just ideas really but it would make for a very quick build.... ------------- CELTIC SUBSONIC SOUND SYSTEMS |
Posted By: mykey
Date Posted: 29 October 2007 at 6:57am
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In those seven years you spoke to god about bass, did he tell you any port lengths? ------------- ......just all them hanging there like giant bananas. |
Posted By: mykey
Date Posted: 29 October 2007 at 7:02am
Bit like turning up for a tailor made suit and they only give you the trousers..... or jacket
I new this was going to happen to you JSG, how many kick in the nuts have you had so far for your kind services?
------------- ......just all them hanging there like giant bananas. |
Posted By: bill-77
Date Posted: 29 October 2007 at 8:07am
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TIME WILL TELL ..BEAWARE ALL SCOOP OWNERS THE ALMIGHTY DUB BOX IS DUE TO TAKE OVER WATCH AND PRAY......
|
Posted By: jsg mashed
Date Posted: 29 October 2007 at 10:33am
|
Hi
Login4: Chamber A is cylindrical to level out forces on the driver cone, to avoid cone failure. But if you drive the unit sensibly you might get away with a cuboid chamber of the same volume. It's not a frequency response issue.
I don't want to use self-port type things because circular is a better shape - it's got the lowest port wall area (=less friction) and the biggest end correction and the best intrinsic rigidity. Also easier to adjust during tuning.
mykey: My sig is a misquote from "Sunshine". God does not offer port lengths unless you worship sine waves and impedence measurement.
Yes there are a few luddites on this thread but hey, what can you do?
------------- ...because Good is Dumb. |
Posted By: TONY.A.S.S.
Date Posted: 29 October 2007 at 2:01pm
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John, one of the reasons that this thread has provoked a kind of hostile response, is that you are being very bold and laying claims to something that is still floating round in cyberspace. At the end of the day you are giving us a modified version of what many have done before, many years ago.
I'm from the old school, so I have never once used a program to design anything. I use a lot of programs to analyze and measure. I never liked the idea of useing someone elses boundries for design. However, I can understand why people do. People will want to test drive before they decide it's the best thing since sliced bread. Having a good response on paper will still not tell us what it sounds like. If figures said it all, we would all be building the same incredible box. All forum members want is actual proof, and that means a box that is standing there slaying everything in its path., and even I wouldn't be so bold as to predict anything like that. ------------- http://www.facebook.com/tony.rossell.3" rel="nofollow - http://www.facebook.com/tony.rossell.3 |
Posted By: mykey
Date Posted: 29 October 2007 at 2:20pm
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Computer says no. ------------- ......just all them hanging there like giant bananas. |
Posted By: JaKe
Date Posted: 29 October 2007 at 2:33pm
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The mighty may come to pass but Dub will stay. JaKe |
Posted By: jsg mashed
Date Posted: 29 October 2007 at 3:00pm
In that case, Tony, this is the wrong thread for you.
I made the effort to spend time modelling the cabinet, and drawing out the plans. I doubt you even took the time to look at them. I am coming from 15 years experience modelling cabs and building to those designs. You have no such experience by your own comments.
Edit: and as I have pointed out, the bandpasses that were done many many years ago were mostly rubbish. Wanna know why? Because they were designed without proper attention to computer modelling. The attitude of "oh well I can do better if I don't let a computer set my boundaries so I'll just pull the designs out of my A.S.S" doesn't belong in professional PA. Now I see why you've gone into AudioFool speakers.
------------- ...because Good is Dumb. |
Posted By: levyte357
Date Posted: 29 October 2007 at 3:26pm
As Tony is the designer of 2x of the best scoop cabs of all time, , I would argue this is the right thread for him to be responding to. JSG, your "cab" will need to prove itself superior to Tony's S118/RX18 cabs if it is to meet your lofty claims. And verily I say unto thee, the "throw" or efficiency of your V18-1200 loaded cab, will not exceed that of an ASS scoop loaded with a 98db efficient PD1850. And there are better drivers that also work in the RX18.  ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: mykey
Date Posted: 29 October 2007 at 3:31pm
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15 years experience, so do you or have you worked for any major player's in the business then? I think this will be good , it makes sense to me
but some port lengths would be good too.
I'll kneel at the end of me bed tonight and ask the MIGHTY ONE what lengths they are
" I haven't uttered a word in eighteen years, not a single word has passed these lips and you come along, bold as you like and ask me what length these ports ARE!!" ------------- ......just all them hanging there like giant bananas. |
Posted By: TONY.A.S.S.
Date Posted: 29 October 2007 at 3:33pm
|
Well John, contrary to your assumption, I did scrutinize your drawing and what I saw was a band pass box. This is not the wrong thread for me, as I am always, even at my age, trying to learn something new. Since being on this forum I have never been critical of anyone regarding design, but peoples attitudes do keep me amused. However, When at least a hundred groups of people have stood in front of the proposed cab, and declared it a winner, then you will have something to shout about. Untill then, I suppose we wait with bated breath. ------------- http://www.facebook.com/tony.rossell.3" rel="nofollow - http://www.facebook.com/tony.rossell.3 |
Posted By: jsg mashed
Date Posted: 29 October 2007 at 3:34pm
Ha! If you think that why do you start a "what's the best scoop" thread every 2 weeks in the SCOOPs forum.
And no, this isn't the right thread for luddites who think computer modelling doesn't work. People who have experience with it know otherwise.
In fact it will have to be even better than that. It will have to have a sufficient margin of superiority to get over all the irrational prejudice.
Now whose making the bold predictions?
 ------------- ...because Good is Dumb. |
Posted By: jsg mashed
Date Posted: 29 October 2007 at 3:36pm
I wish you would bate your breath.
------------- ...because Good is Dumb. |
Posted By: jsg mashed
Date Posted: 29 October 2007 at 3:41pm
HA! If that was true, do you think I'd be giving designs away to ungrateful SCOOP-heads like A.S.S and others?
------------- ...because Good is Dumb. |
Posted By: adambomb
Date Posted: 29 October 2007 at 3:46pm
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Dude.. you were funny.. now your just being rude.
I'm really interested in your design, but, like some other members of this forum, you really should tame you mouth on here.. gets you nowhere.. and insulting one of the grand daddys of pro PA does you no favours ether (Tony A.S.S.).
Stick with the plans / designs and prove to everyone it works better than everything else... ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: LostGrayCat
Date Posted: 29 October 2007 at 3:48pm
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This guy's a Troll. 'Nuff said, 'cept my original comment, he's blowing smoke. <PLONK> |
Posted By: TONY.A.S.S.
Date Posted: 29 October 2007 at 3:50pm
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I'll obviously have to look in the mirror. I've never been called that before. I suppose it's because I don't usually build scoop bins. ------------- http://www.facebook.com/tony.rossell.3" rel="nofollow - http://www.facebook.com/tony.rossell.3 |
Posted By: mykey
Date Posted: 29 October 2007 at 3:52pm
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Your shouldn't have said that, someones gonna to put up a photoshop pic of someone with a scoop for a head now being chased down the By-Pass by the mighty dub pass ------------- ......just all them hanging there like giant bananas. |
Posted By: adambomb
Date Posted: 29 October 2007 at 3:54pm
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I don't think hes a troll. just getting a bit carried away... I like the design / theory (it seams to work for Stasys X after all!!)..
With all this bruhaha it's now unlikely anyone will build one... which is a shame if you ask me. ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: levyte357
Date Posted: 29 October 2007 at 3:54pm
I challenge you to list the details of 1x "what's the best scoop" thread I have started this year, much less "every 2 weeks". If you cannot do this, I will declare you the village idiot.
I can make that bold prediction, because I have heard ASS scoops on numerous occasions, and tested them with various drivers. And so have countless other people. I also own 4x V18-1200 drivers, and have tried them in various cabs. Erm, do you even have a "cut list" for your "cab" yet? ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: jsg mashed
Date Posted: 29 October 2007 at 3:54pm
If you're going to hang about in this thread, why don't you contribute something - like a design or maybe a constructive comment.
------------- ...because Good is Dumb. |
Posted By: adambomb
Date Posted: 29 October 2007 at 3:56pm
|
would you like a shovel? ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: RiddimKid
Date Posted: 29 October 2007 at 3:58pm
| Lol this is gettin out of hand now |
Posted By: TONY.A.S.S.
Date Posted: 29 October 2007 at 4:00pm
|
or a rope. It had to happen. It's been a fun afternoon. ------------- http://www.facebook.com/tony.rossell.3" rel="nofollow - http://www.facebook.com/tony.rossell.3 |
Posted By: jsg mashed
Date Posted: 29 October 2007 at 4:01pm
http://speakerplans.com/forum/forum_posts.asp?TID=6387&PN=1 - http://speakerplans.com/forum/forum_posts.asp?TID=6387&PN=1
Denied!
 ------------- ...because Good is Dumb. |
Posted By: mykey
Date Posted: 29 October 2007 at 4:02pm
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What we need now is Bry to do one of his mental drawings of a Dub Pass eater
------------- ......just all them hanging there like giant bananas. |
Posted By: Disco Stu
Date Posted: 29 October 2007 at 4:05pm
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JSG for my benefit as someone who hasnt modelled or hasnt really got a clue how to model an 8th order bandpass accurately - how do you go about it (I have BB6 if that helps - which seems to be able to model series tuned chambers ok)
What I see from looking at your design and my knowledge of 6th order, is that the two main chambers will function as a 6th order to give your 2 outer humps, then the series ported section will add gain in between those humps, giving 3 main peaks. Is that correct? If not what does the series porting do?
I will try and model some things in BB6 later and if you dont mind critiquing that would be very helpful to me
Stu
------------- All you need to know is: Sensitivity + Power Handling - Power Compression = Max Output My acts: www.myspace.com/thebowiexperience www.myspace.com/scheisseelektronisches |
Posted By: levyte357
Date Posted: 29 October 2007 at 4:07pm
Village idiot, I think when you learn to read a calendar, you'll find that thread was started 07 September 2006 at 6:59am Hopefully, this will not be indicative of everything else that comes out of your mouth. Si tacuisses, philosophus mansisses http://en.wikipedia.org/wiki/List_of_Latin_phrases_%28P%E2%80%93Z%29 - translation ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: jsg mashed
Date Posted: 29 October 2007 at 4:08pm
Sorry adambomb. If I was doing this for money then I'd kiss A.S.S to get my design accepted by those who rate the guy. But I'm not making anything from this so I don't intend to accept his unproductive input.
------------- ...because Good is Dumb. |
Posted By: adambomb
Date Posted: 29 October 2007 at 4:08pm
|
Stu.. check out my links arlier in this thread.. there's a link to a prog that can sim 8th order BP.. hope that helps. A. ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: jsg mashed
Date Posted: 29 October 2007 at 4:09pm
OK I have to concede that.
They said that before they sentanced Gallileo.
------------- ...because Good is Dumb. |
Posted By: jsg mashed
Date Posted: 29 October 2007 at 4:15pm
Hi, well the A chamber resonates highest, near 100Hz, then C in the middle at about 60Hz and then B at the bottom near 30Hz.
I think of it as a parallel-tuned 6th order with A and B, with all the output going into a final resonator with C. But it's just as valid to think of it as a modified series 6th.
There's some SW out there that will do 8th order - there's a link higher up this thread. But I used my own SW. Incidentally, I was thinking of releasing that SW at some point.
------------- ...because Good is Dumb. |