Design of 2x18 Front Loaded Horn
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Topic: Design of 2x18 Front Loaded Horn
Posted By: levyte357
Subject: Design of 2x18 Front Loaded Horn
Date Posted: 29 October 2007 at 6:38pm
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Wondering if anyone has researched this? I'm favouring an approach that allows top loading of drivers i.e WSX style, to allow easy driver access and effective use of Alu heatsink plate.
------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Replies:
Posted By: TONY.A.S.S.
Date Posted: 29 October 2007 at 7:00pm
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Easy to do, just think very big and heavy. You can see how long Martin horns were in the day and indeed our own. My logic would be to build them with even longer horns. If the're folded, they should still be big to take advantage of the 18's. We did a double 18 that was proportionally bigger than the 2x15 BS1200. It was big and heavy and we only sold them into clubs. If you load them from the top you will cutting out a usefull cabinet wall. Draw a rectangle and then start to draw a path that leads you to the front. Don't go down the old Turbo route. (good sounding cabs though they may be) They are front loaded horns, but the shortest in the business. ------------- http://www.facebook.com/tony.rossell.3" rel="nofollow - http://www.facebook.com/tony.rossell.3 |
Posted By: Disco Stu
Date Posted: 29 October 2007 at 8:09pm
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Even Rog says that if you want to go low with an 18" it needs to be the size of a small car
Its a futile process if anything, must you use 18"s? There are more drawbacks than benefits in this day and age with such advanced driver technology. A 15" on a horn long enough to load to 35Hz can be acheived in a box 48"x24"x24" why would you go bigger?
No-one is using 18"s on long horns, why? Cones cant take it, people (even rog) are only using them on short horns and notice that most of Voids catalogue this year (Arcline, Waveform etc.) are using 12" horns.
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: ceharden
Date Posted: 29 October 2007 at 8:12pm
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Interesting comments there Tony. I've been playing with lots of different foldings on paper and I actually really like the Martin WSX,215MkIII style driver access and folding. Actually seems to be the most efficient use of space and easiest to build. I will build my 15" version of the WSX over the winter! |
Posted By: levyte357
Date Posted: 29 October 2007 at 9:08pm
MSE-118 'Quake' Subwoofer 
Description http://www.emacoustics.co.uk/index.php?option=com_content&task=view&id=24&Itemid=99999999 - http://www.emacoustics.co.uk/index.php?option=com_content&task=view&id=24&Itemid=99999999 ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Disco Stu wrote:Posted By: Mike Severloh
Date Posted: 29 October 2007 at 9:30pm
How bout straight horns like the ol´ Community Boxer 2x18" in trapezoidal box with and big additional reflex chamber hooked sideways where the access panel could be ? Modular,yet still stand-alone ? ------------- Mike Severloh. |
Posted By: levyte357
Date Posted: 29 October 2007 at 9:41pm
Not being an expert, I have chosen the WSX or SL36 Horns to tamper with. I think it is just within my capabilities to arrive at a working solution based on one of these. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Disco Stu
Date Posted: 29 October 2007 at 9:48pm
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Hohoho nice try levyte
Ok no plot, but 134dB continuous with 800W equates to 105dB sensitivity and looks estimated since theres no plot to back it up. Factor in power compression and that moves you down to around 131dB at best and 127dB at worst, if I remember right its a PD driver in there so lets look on the brighter side of that and say 131/2dB.
35Hz? With a mouth of around 700x540? Lets look at a horn with a mouth of around 700x576
http://www.billfitzmaurice.com/T48.html - http://www.billfitzmaurice.com/T48.html
Theres a plot for a horn of such a mouth size, admittedly the box for the 18" is larger and the horn longer but it needs to be because an 18" is not only physically bigger but requires a larger rear chamber as a result.
But 35Hz with one box is at best unlikely
Also another thing to consider 109kg! Not exactly a one man lift and probably not a 2 man lift either - the cab shown in the link is 40Kg nearly a 1/3 of the weight and around 350mm shallower which makes a whole lot of difference in some venues - 950mm is a deep cab(37") and awkward to schlep around.
EDIT: Another cab with a similar mouth size is the Looney 700x600 effective mouth size but the horn length only loads to 50Hz - the length is important for extension but without the mouth size aint gonna happen and will give bumps in the response.
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 10:05pm
 Yes Stu, large heavy, but still very well known and effective.. Also the driver is custom PD. The whole point of my exercise is just to explore exactly what kind of SPL/response can be garnered from a 2x driver front loaded horn sub on an approximately 7.5ft horn. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Disco Stu
Date Posted: 29 October 2007 at 10:36pm
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Fair enough definitely 18"s?
Hmm what driver did you have in mind?
I can foresee the following problems - a long horn with an 18" = a large column of air to move for the driver.
This will require the use of a driver with an amazingly strong cone and a large BL factor, and will always be prone to tearing simply because of the diameter of the thing, the distance between one "supporting section" and another is around 17"
As a result of moving the large column of air with just one single unit, the transient response will be poor - so its going to be restricted to sub, and will probably sound "slow"
Again with the tearing thing - if you look at the BFM subs they load through slots, this can help with the response to an extent BUT raises the compression ratio and puts increased stress on the driver, so I think the horn needs a smooth expansion with quite a large surface area.
Just some starting points for you!
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: Timebomb
Date Posted: 30 October 2007 at 1:32am
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18s tend to have larger displacement than 12s, even the caire
12sw wich has a very large displacement for a 12 can be outdone by most
decent 18s and almost doubled by some beasts. using 12s tends to
lead the design of a long path horn to a higher compression ratio /
smaller rear chamber wich puts more pressure on the cone with a 12,
yes its harder to keep an 18" cone rigid but they dont tend to
have to travel as far and the load is spread over an area twice the
size of a 12. The are advantages of 18s over 12s and plenty of drivers out there can take horn loading, and plenty of pro manufacturers use 18s in horns. Id favior the spiral folding style as it has no 180 degree bends but horns like the wsx would be easer to heatsink. |
Posted By: levyte357
Date Posted: 30 October 2007 at 2:37am
2x V18-1000  ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: tommysb
Date Posted: 30 October 2007 at 8:54am
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Bottom line is to properly get down to 35Hz region (with a horn), you
need a mouth that'll support that cutoff, or some clever way of getting
round it, like a tapped horn. If the mouth is too small for the
wavelength, the pressure wave in the horn won't effectively couple to
the room, and be partially reflected back down the horn, as if it were
just a sealed tube. So think about mouth size! You're gonna need a lot
of boxes to do it, whatever, because of this |
Posted By: levyte357
Date Posted: 30 October 2007 at 10:14am
I believe the standard WSX goes down to 40hz with 2x cabs. So I would imagine a correctly modified 2x driver cab, with slightly extended horn would achieve approx 40hz at very high sensitivity quite easily. Question is, can hornresp model 2x driver front loaded horns accurately? ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Disco Stu
Date Posted: 30 October 2007 at 12:10pm
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What about logsquared 2x Kilomax horn - that might work! 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: 30 October 2007 at 12:15pm
I'm only considering WSX/SL36 for Modding, but just been looking at SL36, and that looks much easier to Mod for 2x drivers by increasing front chamber, horn and Mouth. Questions, a)should drivers share rear chamber or have separate chamber/driver? b)Should drivers fire thru individual throats matched to Sd into common horn throat or single horn throat matched to 2x Sd, with drivers wired in phase? ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Disco Stu
Date Posted: 30 October 2007 at 12:22pm
I wasnt suggesting you substitute 1x18 for 1x12. 2x12" yes.
If you arent worried about size yes, but you can use a smaller cross sectional area with a 12" giving a long horn, high efficiency and a smaller overall box, and if you want the higher efficiency of the 18" use 2 1x12"s 2 smaller boxes, easier to lug about, scaleable for smaller venues and able to be used in a V configuration to achieve more ouput. A smaller cone also allows a higher compression ratio with less chance of cone failure.
I think the word is DID, has Tom Danley got a horn for an 18"? Has Walt? What about the JTS Growler? 12 Pi? Bassmaxx? What percentage of horns from Rog use 18"s? Older designs still use 18"s, less and less new designs are doing so. Follow the trends.
Times are changing, drivers are changing, and at last peoples attitudes are changing
The stigma of 18"s being the only driver for a bass horn is starting to change. Even people on this forum are looking at mostly 12"s in their new basshorns from what I can see.
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: mykey
Date Posted: 30 October 2007 at 12:34pm
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Tom didn't design the Lab, if thats what you were thinking Stu?
if not I'll get me coat ------------- ......just all them hanging there like giant bananas. |
Posted By: Disco Stu
Date Posted: 30 October 2007 at 12:57pm
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The lab is a 2x12 anyway
I was talking about DSL Tapped Horns
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: 30 October 2007 at 2:41pm
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I am not challenging or disagreeing with current horn trends towards smaller drivers, just enquiring of the experts how to design this thing. If it turns out to be a waste of time, I'll try something else, but this is the purpose of this thread for now. Regards ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Disco Stu
Date Posted: 30 October 2007 at 2:56pm
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What sort of frequency response do you want, what sort of pack space are you hoping for?
SL36 if its the one im thinking about is barely better than an HD15 the horn is so short it barely loads to 60Hz.
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: 30 October 2007 at 3:06pm
HxWxD (inches) Standard WSX 40x21x37 My Cab 48x24x48, In terms of response, looking for, +5db 35hz-40hz on V18-1000 loaded standard WSX. +3db 40hz-80hz on V18-1000 loaded standard WSX. Using slightly smaller chambers, but longer horn/larger horn mouth. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Disco Stu
Date Posted: 30 October 2007 at 6:08pm
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1200x600x1200 is a big old box, should be doable the WSX hasnt got a hugely long horn but you will need multiple boxes to get the required mouth area remember to make the mouth 1/4 of the largest wavelength you wish to reproduce
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: tb_mike
Date Posted: 30 October 2007 at 9:10pm
Tom danley and friends DID design the labhorn,with the custom designed lab12 driver.
If you see the old prosoundweb forum posts its easy to see.
Look at the latest bassmaxx basshorns - multiple 12"s achieved good results in the PSW shootout.
|
Posted By: mykey
Date Posted: 31 October 2007 at 3:52am
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someone else designed it he checked it
probably got a few boffs working for him ------------- ......just all them hanging there like giant bananas. |
Posted By: levyte357
Date Posted: 31 October 2007 at 9:45am
Not sure if these inputs are anywhere near correct, so haven't submitted SPL pic.  Note: S1, Vrc, Lrc are all x2 from original WSX cab, in theory to support 2x drivers. Also note larger cab should allow longer Horn length and larger mouth area. I think I have Nd indicating 2x drivers, but still not sure if Power should be specified at 4 ohms when plotting due to 2x drivers. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: MarjanM
Date Posted: 31 October 2007 at 11:10am
What do you mean? Tom didnt design it? ??????????????????????????? ------------- Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713 |
Posted By: adambomb
Date Posted: 31 October 2007 at 11:58am
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Mykey.. you should go read prosoundweb.. honestly. ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: Disco Stu
Date Posted: 31 October 2007 at 12:49pm
What the whole thing?  ------------- 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: mykey
Date Posted: 31 October 2007 at 1:45pm
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I was fishing, didn't seem to work
would have helped if you said...your right he didn't. ------------- ......just all them hanging there like giant bananas. |
Posted By: MarjanM
Date Posted: 31 October 2007 at 1:49pm
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Then who did it? So he didnt designed the TH-115 either. Right? Or Servodrive BT-7 (which by the way has completely same design as Labsub), beside the use of 12s insteat of 15s. Sorry Mykey but your full of $#@%#$ this time. ------------- Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713 |
Posted By: mykey
Date Posted: 31 October 2007 at 1:57pm
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Correct me if I'm wrong
But I keep seeing allot of you use EXP when using horn response
are you after a rough idea lev, or near to spot on?
because really I think you should be putting in all the expansions and length's and using Con instead of Exp?
even if you tell it all the expansions and lengths then look at the schematic, you will see in between each panel length there is still an Exp rate
while in most horns they are still flat/straight panels
so I always use Con and expansions and lengths
And isn't 808 a small throat for 2 drivers?
edit: or is 808 double the wsx throat? ------------- ......just all them hanging there like giant bananas. |
Posted By: mykey
Date Posted: 31 October 2007 at 2:01pm
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Marjam read the post before yours, I know he designed it. ------------- ......just all them hanging there like giant bananas. |
Posted By: TONY.A.S.S.
Date Posted: 31 October 2007 at 2:19pm
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While all you girls stare at the screen and fight. I'm tempted to go back in the factory and make the damn thing, It will be quicker. ------------- http://www.facebook.com/tony.rossell.3" rel="nofollow - http://www.facebook.com/tony.rossell.3 |
Posted By: mykey
Date Posted: 31 October 2007 at 2:47pm
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I'm still trying to find out what full of six letters can be ------------- ......just all them hanging there like giant bananas. |
Posted By: levyte357
Date Posted: 31 October 2007 at 6:51pm
 ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: levyte357
Date Posted: 31 October 2007 at 6:59pm
Thanks Mykey. I'm no hornresp expert, and need all the advice I can get. Just using hornresp to get an idea of whats needed in terms of chamber size,horn length/mouth size. Then I'll find out "again", how to associate dimensions with horn path. Yes 808 is double WSX size. Regards ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: jsg mashed
Date Posted: 31 October 2007 at 7:50pm
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Actually each section is linear, not conical, becase the area increases linearly rather than as a square law. On the other hand, the shorter the sections, the less difference it makes which function you choose. ------------- ...because Good is Dumb. |
Posted By: tb_mike
Date Posted: 31 October 2007 at 8:28pm
Actually yeah I remember something about some one else doing the CAD for him. Hes definately onto a winner on his own danleysound stuff now. JSG MASHED : Good point that alot of people miss. Making the physical horn match the theoretical one is tricky. With compromised real horns the short sections approximating expo flares dont seem to matter as much. |
Posted By: levyte357
Date Posted: 31 October 2007 at 8:30pm
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Tony et al, I'm thinking of something like this,  Maybe the front chamber needs reduction  .------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Tekasis
Date Posted: 31 October 2007 at 9:41pm
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Is this design for kick bass or high bass or something ? What about the rear of the drivers where the real low subs comes from, it's all sealed!!! You sure you drawn the drivers the right way around ?
That ain't gonna drop heavy like the Hog or the DubSub! You don't see that the rear is open up to leggo the sub bass ?
 |
Posted By: adambomb
Date Posted: 31 October 2007 at 10:44pm
lol
umm.. that's incorrect... but funnily enough a misconception I had once.. (when I was about 12). ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: levyte357
Date Posted: 31 October 2007 at 11:45pm
Tek, scoop is a rear loaded horn. WSX, Labsub, Looney are front loaded horns. For all horns, factors which decide how much sub you get are, 1) Driver(s) 2)Chamber size 3)Throat size/Volume 4)Horn length 5)Horn Mouth Size Which then dictate cabinet size. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: mykey
Date Posted: 01 November 2007 at 4:32am
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Lev, you have 1 driver behind the other in your drawing? ------------- ......just all them hanging there like giant bananas. |
Posted By: mykey
Date Posted: 01 November 2007 at 5:30am
http://img225.imageshack.us/img225/7515/levbin1ql4.jpg%5b/IMG%5d"> ------------- ......just all them hanging there like giant bananas. |
Posted By: adambomb
Date Posted: 01 November 2007 at 8:59am
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I would mod that design so both are parrallel in relation to the horn.. like mykey said.
To be honest I reckon you would be much better with 2 boxes.. same result but easier to move. ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: wasup
Date Posted: 01 November 2007 at 9:14am
Hey look havnt read the whole thead so maybe my question has been mentioned or answerd! Anyway if you put two drivers next to each other like in the digram/drawing above wont they fight against each other! Like in one canceling parts of the others sound/frequency out!Perhaps thats the point or part of this thread sorry!
Sorry for my ignorance but if it was two cabs next to each other one may have to splay them a little! Why ist that in this case so....?
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Posted By: biotec
Date Posted: 01 November 2007 at 9:20am
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one driver has a longer horn path than the other?
That design will be inneficient and peaky as the drivers will be out of phase over some of the response. It's like using two different types of cab.
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Posted By: adambomb
Date Posted: 01 November 2007 at 9:28am
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yea.. would be like having say and 1850 and a CV bin (extreme example) sat next to each other covering the same frequency range.. not gunna be good. ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: Mark James
Date Posted: 01 November 2007 at 11:55am
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yes each drivers sees a different horn and will have a different responce, and be out of phase and time with each over. also blah bla blah ------------- me so horny me love you long throw horn loaded for her pleasure |
Posted By: levyte357
Date Posted: 01 November 2007 at 12:13pm
Yes Mykey, see that quite clearly. Trying to avoid Lab method of mounting drivers vertically at center of spiral horn, as this would complicate build considerably. Simplest solution to the above, would be to have drivers side by side; but that would result in cab 36" wide, similiar to tuba. Would it be possible to arrange the 2x drivers in separate identically sized chambers, but firing into a common chamber at the start of the horn? ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: jsg mashed
Date Posted: 01 November 2007 at 12:47pm
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Just apply delay to the driver with the red arrow, enough to compensate the path difference vs. the blue arrow. Maybe also use a lower low-pass freq on the red driver (eg red up to 100Hz, blue up to 180Hz) ------------- ...because Good is Dumb. |
Posted By: Mark James
Date Posted: 01 November 2007 at 1:03pm
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yeah you are effectivelyusing two different horns, the phase issues would be horrific id imagine, it wont just be delay issues, group ddelay would go awol id imagine????? ------------- me so horny me love you long throw horn loaded for her pleasure |
Posted By: levyte357
Date Posted: 01 November 2007 at 1:23pm
How about compromising layout/cab by arranging drivers as below, (Looking at cab from above speakers). Also Adjusting horn length to ensure "lead" driver sees 7.5 ft horn?  Thinking this would reduce path Difference seen by both drivers to approx 9" instead of 18"? ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: mykey
Date Posted: 01 November 2007 at 1:38pm
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Your gonna have to abandon that idea Lev, I'll PM some sketchs to you that you can have a play around with
JSG  , who are you really?------------- ......just all them hanging there like giant bananas. |
Posted By: levyte357
Date Posted: 01 November 2007 at 2:37pm
Mykey cheers for input and PM's... But, World already has 2x12 labhorn, short horn 2x18 FK1's/turbo's, long horn 1x18 cabs . (WSX/Quake), short horn 1x18 (186/1850 horns). So it will be 2x18, on approx 7.5ft horn  .------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: mykey
Date Posted: 01 November 2007 at 2:47pm
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Ok I'll put up the '2' sketch's I did then, that are none of the above these are only rough guy's so don't take the mick, I know you guys are thinking...tit's
http://img509.imageshack.us/img509/3028/levsdrawingnj6.jpg%5b/IMG%5d">
 ------------- ......just all them hanging there like giant bananas. |
Posted By: mykey
Date Posted: 01 November 2007 at 2:49pm
http://img148.imageshack.us/img148/8320/wsxl2jk2mu9.jpg%5b/IMG%5d"> slightly adjustedversion of the original mistake ------------- ......just all them hanging there like giant bananas. |
Posted By: mobiele eenheid
Date Posted: 01 November 2007 at 6:02pm
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As the drivers are relatively small compared to the frequencies the reproduces would they not act as a single driver?
Wkr Johan
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Posted By: adambomb
Date Posted: 01 November 2007 at 6:13pm
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Lev.. take a look at Centauri s website : http://www.centauriaudio.com.au/diy/hornfold.html - http://www.centauriaudio.com.au/diy/hornfold.html
Brilliant Stuff! and a real help in designing folded horns.
If I was trying to do what your trying to do.. I would use the info in the above page with hornresponse and autocad to get the box I wanted.
Do something new and different.. not a re-hashed double box of a known commercial design.
You could make something really unique with a bit of work! ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: levyte357
Date Posted: 01 November 2007 at 9:51pm
Cheers. Have seen that site before... But don't have autocad or time to start completely from scratch. I really like WSX, so when I understand them inside out, I'll be able to design my own drivers and horn for "them" from scratch. Think I'm almost there with this jobby.. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Mark James
Date Posted: 01 November 2007 at 10:16pm
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@mykey that first sketch looked quite interesting, ie i havnt seen that layout before i dont think and it looks quite logical, could be quite a nice idea. ------------- me so horny me love you long throw horn loaded for her pleasure |
Posted By: Disco Stu
Date Posted: 02 November 2007 at 1:59am
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Jeff R did something very similar for a Lab 12 driver not so long ago. Good design, still some wasted space.
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: mykey
Date Posted: 02 November 2007 at 2:36am
Thanks Markk, that was a five minute sketch after turning on my pc and seeing JSG saying delay one of the 18's and Lev saying can I do this.... .
I say don't run before you can walk.
The second one was 2 min's, the first is not to scale and proportions all over the place but it was just to give an idea of layout
------------- ......just all them hanging there like giant bananas. |
Posted By: levyte357
Date Posted: 02 November 2007 at 3:12am
What exactly do you mean by that, Mykey ? ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: mykey
Date Posted: 02 November 2007 at 12:17pm
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http://www.phrases.org.uk/meanings/proverbs.html - http://www.phrases.org.uk/meanings/proverbs.html
If your going to design horns learn the bare basics ------------- ......just all them hanging there like giant bananas. |
Posted By: levyte357
Date Posted: 02 November 2007 at 12:25pm
Mykey, I started reading about the "bare basics" 2 years ago. I'm not designing a horn, I'm modifying an existing design (WSX). At Uni, I had to learn mostly by example "real quick", so I have the intelligence to arrive at a working prototype "real quick", with help from the experienced experts here. I started this thread, so I could put forward ideas, and be corrected/pointed in right direction. Regards ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: mykey
Date Posted: 02 November 2007 at 12:38pm
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Thats cool, at least your doing something, seems that only 0.1 % are designing new stuff on here
Its refreshing to come on here and see new designs when they happen
 Come on guy's stop swapping old drawings and show us some sketch's, you may have a 'Bertha' in ya scrap book's.
Look forward to seeing your new design Lev. ------------- ......just all them hanging there like giant bananas. |
Posted By: levyte357
Date Posted: 02 November 2007 at 12:43pm
Cool. What did you think about the slightly offset drivers idea to minimise cab width and shorter horn length seen by 1st driver? "Think" I first saw this done by Bill Fitz in 2x15 Tuba36. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: mykey
Date Posted: 02 November 2007 at 2:20pm
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Another quicky
http://img222.imageshack.us/img222/5213/70177337nx6.jpg%5b/IMG%5d">  ------------- ......just all them hanging there like giant bananas. |
Posted By: LostGrayCat
Date Posted: 02 November 2007 at 3:45pm
Who's missing?  |
Posted By: adambomb
Date Posted: 02 November 2007 at 4:18pm
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Wayne? ------------- http://www.freespeakerplans.com" rel="nofollow - www.freespeakerplans.com |
Posted By: levyte357
Date Posted: 02 November 2007 at 6:45pm
After chatting to couple of members by PM, might be going for 2x15's instead  .However finding 15's with lowish Fs, largish Xmax and right EBP is proving difficult. Looking at 15TBX100 at the moment.
------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
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Posted By: levyte357
Date Posted: 02 November 2007 at 7:47pm
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Figures for 2x B&C 15TBX100 Drivers arranged side by side, making cab approx 30" wide.  ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: ceharden
Date Posted: 03 November 2007 at 2:38am
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What are the actual design aims of this Lev? Here's a hint: Try simulating an 18LW1400 in a WSX. Stack of 3. Now for me that has it all. Flat to close to 40Hz, smooth response,good efficiency,sensible sized cab. What more do you want? |
Posted By: levyte357
Date Posted: 03 November 2007 at 2:55am
Simulated loads of Drivers in WSX earlier this year. From sims I have run, V18-1000 is baddest guy in WSX. 18sound is flatter, but BL lower than V18-1000 and Vas higher, so runs out of Xmax at lower SPL. But thats old news. I want cab that reaches just below 40hz in singles, that also approaches scoop/lab sensitivity. Which means 2x drivers on long horn with big mouth. 4x Cabs must be flat to 35hz. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Disco Stu
Date Posted: 04 November 2007 at 9:37pm
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http://www.billfitzmaurice.com/T36.html - http://www.billfitzmaurice.com/T36.html Tuba 36 wide enough to fit an 18"?
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: tb_mike
Date Posted: 04 November 2007 at 10:15pm
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Howcome your looking for such a low Fs? The horn adds mass to the cone anyway. It looks to me that the only way to achieve your aims is to have a wobbley response like the BF tuba. |
Posted By: tb_mike
Date Posted: 04 November 2007 at 10:20pm
Very good point. Id explain it more as frequency and wavelength proportions. JSG mashed did you calculate the delay in output from the 'late' driver and if its audible before reccomending delaying it?What looks bad on paper needs to be verified. I think people need to inspect some basics on wavelength,and group delay audibility. |
Posted By: tb_mike
Date Posted: 04 November 2007 at 10:23pm
Nope.The horn is being excited at two different points.I dont think it will be audible below 80hz.But I havent bothered calculating it,Im meant to be studying right now There will be two different reflections from the start of the horn that will appear at the mouth at some high frequency probably out of passband. |
Posted By: jsg mashed
Date Posted: 05 November 2007 at 11:08am
If wavefronts from the two drivers arrive out of phase, this will cause amplitude response issues due to cancellation. This is why the original WSX uses a "letterbox" throat section - it reduces path length variations across the cone.
You need to remember that if the drivers are run from the same signal, thats 2*18=36 inches of source. Add the reflection from the inside end of the duct and that's effectively 72 inches or 180cm of distributed source. That fits a half wave at just below 100Hz, so sensitivity is already rolling off. There's not much point in using a horn if you only want to go up to 100Hz.
Delaying the second driver creates a more concentrated wavefront since output from the first and second driver arrive in phase. There's still the reflection from the second driver - this is why I suggest running the second driver to a lower cutoff - so it contributes where it works well, and not where it doesn't.
There's also an impedance angle. Impedance in the context of active systems is confusing, but basically, the second driver will see a greater load impedence because there's already pressure right in front of the cone (fron the first driver) that is in-phase with the second driver's output. This permits greater aucoustic power to be developed for less cone excursion. The loading is similar to the case of 2 drivers close together and run in-phase.
I guess there's also another, more perceptual angle to this. Percussive type signals are common in bass (drums, string plucks) and are characterised by high narrow peaks that resemble a band-limited impulse signal.
Now, if you run such a signal through an all-pass that fiddles the phasing without changing amplitude content, you will see the the peak is not as high. The same energy is there, but it has been spread around. If you play this signal back, you may find that the phase artifacts are too small to be discerned explicitly. But you may also find that you *can* sense the disappearance of that high instantanious SPL associated with the peak.
I think this is down to a combination of non-linearity in the ear and the Haas effect, but your milage may vary.
------------- ...because Good is Dumb. |
Posted By: levyte357
Date Posted: 05 November 2007 at 2:17pm
I guess we are still looking at the original my preferred 2x18, well here is an SPL plot, to further spark debate..  ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: tb_mike
Date Posted: 06 November 2007 at 3:16am
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Levyte: 170Litres backchamber.If you ported this large rear chamber at say 34hz this may help like old Wbins.But they had cutoffs closer to 60hz. Ive been to indoor gigs where all they had were a few crusty wbins with ported rear chambers,I was happy enough after half a dozen drinks :) Personally just build a WSX-like thingand be done with it. You can see the justification of tom danley,to use low Fs car style lab12s for tiny rear chamber,and maximum horn volume. I think the are 20Litres or so each. JSG : I simply see it as a delayed source,0.001second behind .I dont think is is audible at 50hz!By high narrow peaks do you mean in the time domain,a peak of energy with a fast decay? It would be nice if we could get a model going like the hornresp waves function,see it happening. |
Posted By: mykey
Date Posted: 06 November 2007 at 3:19am
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I can't still get me head round this
are you still going for a double wsx?
WHY?
just have 2 wsx, i thought you were designing something new, something different?
and a cab of over 36'' wide??? are you OK lev? don't need a lie down?
well you will after carrying it.
I'd better go before I start winging again ------------- ......just all them hanging there like giant bananas. |
Posted By: djrockstar4u
Date Posted: 06 November 2007 at 3:23am
| Yeah, I wouldnt do a double WSX's, it'll break your back trying to move it lol. You'd be better building two seperate cabinets, you'd have a much better time trying to focas the bass |
Posted By: levyte357
Date Posted: 06 November 2007 at 4:04am
Looks like general consensus is, 2x18 cab with drivers inline as originally detailed, won't manifest noticable phase issues until after 100hz. So cab will be at most 24" Wide. Why do this? 1)1x 2x18 WSX is cheaper than 2x 1x18 2)Want to see the expression on peoples faces when they see 4x cabs, and hear 8x 3)For smaller gigs, want to be able to just take 2x subs, and still have sub downto approx 38hz. 4)Mate of mine has PA hire firm, and sometimes plays gigs with just 2x Nexo subs and Mid tops. The subs have 2x18 + 1x15 in 1x cab , and always impresses the crowd with so few subs. So it proves single driver subs are not always the way. Just means, 2x man install, and tailgate lift van is in order. Also WSX are getting a bit common now, want something slightly different. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: mykey
Date Posted: 06 November 2007 at 4:26am
I will say though, that graph looks lush
Lev can you try putting the 15'' version of the ciare 12sw in? and the 18'' version, both rubber surrounds
I heard these in a short horn and was very very impressed with the lows
Think they have changed the codes to the ciares now though, so mite not be 15sw
CharlesV if your reading, is the ciare 12sw been changed? ------------- ......just all them hanging there like giant bananas. |
Posted By: jsg mashed
Date Posted: 06 November 2007 at 11:00am
You'll still have horn mouth area issues. 38Hz has a long wavelength compared to the mouth area of 2 WSX.
OK, think of it like this. You start with 2 original WSX. Then:
- if you make them dual-driver you get 2* the power and 3dB gain until they start to cancel which will begin a little below 100Hz.
- if you add 2 more ordinary WSX, you also double the power but you also double cab volume and total mouth area. More like 6dB boost, lower f3l and (if stacked correctly) no loss at the upper end.
So yes a dual-driver cab is louder than a single cab, and if that's what you need, fine. But 2 doubles will lose against 4 original cabs.
If you want good downward extension from a small number of cabs, there are better ways to do this but...
I think being cool/fashionable is a big factor with you. Am I wrong?
------------- ...because Good is Dumb. |
Posted By: MarjanM
Date Posted: 06 November 2007 at 11:30am
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Excuse me for my ignorance but.... Are you aware how big will those boxes turn out? You will not be able to move them trough a single door. It will be more of a 3 to 4 man lift (around 120-130 kg). I know this very well. I have 4 Lab subs and they are smaller than your imagined box. I also have 12 double 15 horn loaded selenium 1505 boxes and i regret every time i move them for not making them singles (also smaller and lighter then yours). Oh, by the way do own a cargo van or some other king of transportation for them? ------------- Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713 |
Posted By: levyte357
Date Posted: 06 November 2007 at 11:51am
Yes, I am going for the inline driver configuration, so looking at a cab that is approx HxWxD 48"x24"48. Regards. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: MarjanM
Date Posted: 06 November 2007 at 11:56am
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Take my advice and dont do it. PM me your e-mail so i can send some photos of a project like yours dismanteled after being realised it is a PITA to move. It goes far beyond your idea. It is 4 x 18 folded horn :-) ------------- Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713 |
Posted By: levyte357
Date Posted: 06 November 2007 at 12:09pm
Thanks for input there... The big factors here are costs and number of cabs used for gigs. My cabs are kept in secure storage with lift facilities, and I have access to box van transits with taillifts. I have a number of guys who also help me move cabs. So transport or storage is not an issue. I need a cab that can provide simular sensitivity to a scoop over 40-80hz with flatter response, Which allows me to do gigs with either 2x, 4x or 8 subs. I like the WSX design/look, and have modelled a number of drivers in it, for quite a while. I need approximately 2x the SPL it provides from 1x cab, and it looks like 2x18 is the way to do it. Regards. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: MarjanM
Date Posted: 06 November 2007 at 12:29pm
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Why dont you build two 2x18 reflex boxes for smaller gigs. I have 12 1x18 reflexes that goes for small gigs. You cant be so much flexible with that big of a boxes. If i show up on some nice corporate gig with two monster cabs they will freak out and never call me again. ------------- Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713 |
Posted By: levyte357
Date Posted: 06 November 2007 at 12:41pm
Don't really have much use for 2x18 relfex now. For House parties I can use X1 or 1xMini scoop. For Small Halls I can use 2x scoops, large halls 4x full scoops. Wine bars, 2x mini scoops, but they are always too loud. 48x24x48 cab is only approx 18" deeper than most decent scoops, and "I think" is approx size of a lab. For smallish corporate gigs where looks are as important as sound, I could use 2x of these, and 1x JBL/Vega 2x15+2" reflex cab or 1x W8C (borrowed) ontop of each cab. Looks less imposing than seeing guy's pulling 4 WSX out of a lorry. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: MarjanM
Date Posted: 06 November 2007 at 12:46pm
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It is you choice but i can count on one hand how many labs have seen a gig in the past year. It is easyer to take 4 single 18s than 2 labs. I can pack 8 single 18s in my Peugeot partner or just one labsub. I dont have to go to a corporate gig with big combi like transit is. I can take 4 single 18s and 4 RCF ART300a and are super cool for around 400 people and the setup is ready in 30 min. ------------- Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713 |
Posted By: ceharden
Date Posted: 06 November 2007 at 12:54pm
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The mouth of a WSX is not really large enough as-is for one 18" driver on that length of horn. You don't get the full potential of the cab until you have at least three cabs per side. If you did your modelling in 2xpi you'd see the massive roll-off on the low end. If you want to do smaller gigs with one cab per side and have sub to 38Hz, what you need is a decent twin 18" reflex box! Or for the same cab volume you could probably have two per side. I just don't think the design you're proposing will do what you want it to in reality. |
Posted By: ceharden
Date Posted: 06 November 2007 at 12:55pm
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He he, Marjan and I thinking/writing the same thing at the same time, just I was slower at typing! |
Posted By: levyte357
Date Posted: 06 November 2007 at 12:55pm
Excellent. But how simple is setup for 2x subs, and 2x 3 way passive Midtop cabs? 2x amps, 4 speaker wires ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: levyte357
Date Posted: 06 November 2007 at 1:02pm
In theory true, however I hear a couple of clubs use WSX in singles, and that they sound suprisingly good. I'll get plans sized up correctly, and get someone to build prototype, I have v18-1000 lying around, and can borrow another 1x. So won't really cost me anything apart from time to see how well it works. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: MarjanM
Date Posted: 06 November 2007 at 1:14pm
Very simple RCf ART 300a are active tops. For bigger gigs it does not matter cos you bring lots of gear anyway. oh and when you have a 4 ohm horn box or 2x18 reflex it is the same setup wire wise isnt it? And that can be one 4 wire cable so no need for two speaker wires :-) ------------- Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713 |