Single 21" reflex plans?
Printed From: Speakerplans.com
Category: Plans
Forum Name: Ported Enclosures
Forum Description: Post all your reflex and bandpass and 'other' boxes with holes in stuff here...
URL: https://forum.speakerplans.com/forum_posts.asp?TID=96218
Printed Date: 23 April 2024 at 11:12pm
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com
Topic: Single 21" reflex plans?
Posted By: Mrtiff
Subject: Single 21" reflex plans?
Date Posted: 18 July 2016 at 1:56pm
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Any plans anywhere? Struggling to find anything online. Needs to be as small as possible, ideally 60x60x60cm. Thanks |
Replies:
Posted By: wires
Date Posted: 18 July 2016 at 2:03pm
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Standard 21" driver, reflex and small enclosure is going to be a compromise. B&C used to have a decent reflex plan, but I believe it was bigger box than what you are after. Worth a look or just design one I guess. |
Posted By: Crashpc
Date Posted: 20 July 2016 at 9:25pm
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60*60*60 for 21" is not doable in a way one would like to "spend" such expensive speaker. It would work for 18SW115 tho... ------------- Nikon and Canon people should not be married to each other. Why did you let this happen? |
Posted By: corell
Date Posted: 23 July 2016 at 6:02pm
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you have a particular chassis in mind? if not, 21lw1400 will work in small enclosures (but wont play deep...) |
Posted By: Crashpc
Date Posted: 25 July 2016 at 8:16am
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B&C 21SW152 will also work in about anything, but it all looks costly to do that, and not use full potential of the speaker. I like the idea of large speaker with strong motor in smallish box, but one needs to know the compromise. ------------- Nikon and Canon people should not be married to each other. Why did you let this happen? |
Posted By: Crashpc
Date Posted: 11 January 2017 at 5:53pm
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Well, having 18SW115, I´m now looking at B&C 21DS115. Might work in 60x64x75cm box. But larger would bring more bang/buck ratio for sure! I´m thinking this as universal (one crazy man) transportable (smallish) system with high power density and living room gadget, than anything else. ------------- Nikon and Canon people should not be married to each other. Why did you let this happen? |
Posted By: Father-Francis
Date Posted: 05 February 2017 at 3:42pm
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Am working on a box it's 900h*600w*770d ,working on the tuning and port lengths, who's good at that could pm you the details, so you can help check that what am doing is right , I don't want to spend to much time doing paper and software sims ,I start cutting, Tuesday. ------------- Music is the strongest form of magic.(+45 31879997)blakmanpro@gmail.com, foa@sweetboxaudio.dk |
Posted By: Crashpc
Date Posted: 05 February 2017 at 3:50pm
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Father-Francis: Modeling mine on weekend too: http://www.picfront.org/d/9vqW" rel="nofollow">  640h x 620w x 780d, Around 32Hz when slightly dampened (stuffed). Should work outside, and has ports large enaugh to get at least one stuffed for home cinema usage (28Hz tuning, for two stuffed it would be 25-24Hz tuning, working down to 20Hz, but not optimal) I might look into yours. ------------- Nikon and Canon people should not be married to each other. Why did you let this happen? |
Posted By: Father-Francis
Date Posted: 05 February 2017 at 4:07pm
------------- Music is the strongest form of magic.(+45 31879997)blakmanpro@gmail.com, foa@sweetboxaudio.dk |
Crashpc wrote:Posted By: SouthwestCNC
Date Posted: 05 February 2017 at 4:12pm
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half one of these? http://www.eighteensound.com/Portals/0/EnclosuresKits/18sound_double%2021%20kit.pdf" rel="nofollow - http://www.eighteensound.com/Portals/0/EnclosuresKits/18sound_double%2021%20kit.pdf |
Posted By: Father-Francis
Date Posted: 05 February 2017 at 4:21pm
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It's a BR am working on boss , ------------- Music is the strongest form of magic.(+45 31879997)blakmanpro@gmail.com, foa@sweetboxaudio.dk |
Posted By: SouthwestCNC
Date Posted: 05 February 2017 at 4:36pm
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Of course, But would you consider that a true bph. Looks pretty close to a reflex to me. |
Posted By: krazyneil
Date Posted: 05 February 2017 at 9:14pm
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I think tony did a Q21 for somebody might be worth asking bee if he still has the plans ------------- GOD TOLD ME TO DO IT !!!!! |
Posted By: Father-Francis
Date Posted: 10 February 2017 at 9:05pm
    So some 21" Pd's landed from Andy , prototype box cut and am putting it together Ready for testing from Sunday , will let you know how it sounds .  ------------- Music is the strongest form of magic.(+45 31879997)blakmanpro@gmail.com, foa@sweetboxaudio.dk |
Posted By: Father-Francis
Date Posted: 11 February 2017 at 7:13pm
  So will be testing tomorrow, will keep you updated ------------- Music is the strongest form of magic.(+45 31879997)blakmanpro@gmail.com, foa@sweetboxaudio.dk |
Posted By: AndersB
Date Posted: 13 February 2017 at 10:09am
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I have built a total of 12 boxes, using 21" drivers ,,,, but a little higher and deeper than 60 60 60 ..... = 61 wide, 90 height, to make room for long bottom ports, and 73 deep, for added volume, and better internal ratio (no square design, of inside measurements.) construction foam and bitumen sheets inside as dampening. two round ports at 20cm diameter. They can be a bit smaller, in volumen, but i would also say 60 60 60 is too small, considering ports should be (very) large.... I used 18mm birch plywood, with dual front 36mm,,, .... and one crosssection of 3 stiffeners going from front/back - top/bottom - and side/side, meeting in the middle .... Accoustically, when i put the setup as 2x4 boxes, they are able to play so deep, that your stomach really turns, hard to describe otherwise, i have not heard anything like it... i used 4 amps at 2500w (4000w peak), 4 ohm. and a record player! ... digital songs dont play as deep... the force of 21" inch really shows in this ported design...: A 18" driver would not be able to go higher than 400-500 w, due to excursion limits - it's around 13-15 mm at this power lvl, when you look at excursion around the 30 Hz .... meaning a 18" ported design really is meaningless for highest output. ... --- when 21" is used, excursion max is more like 1300-1500 watts at 30 hz ... only drawback to using 21", is that the big enclosure, makes the box have a rather long echo, so i cant play the higher end bass (100-120 hz) very precisely... (compared to e.g. a tight punch from a 15" JBL 2226) ... but if highest and deepest possible bass output is required, you are on the right track. --- nothing compares to 21" port reflex :)) https://www.dropbox.com/sc/1cwipl3we6gdjsv/AACErnbIkQWkSpc_A21pykz1a https://www.dropbox.com/s/9temmlasmlpdr11/2013-10-22%2020.36.08.jpg?dl=0 https://www.dropbox.com/sc/bk8ojpwoc2xykvq/AAB-h6gbji1Z-qTLyPyg9Xaaa https://www.dropbox.com/sc/9v3b2h3fwztt90x/AAAccqLvx1HMovEAQ8A-a4uia https://www.dropbox.com/sc/u7v3gw2uckk02ui/AAA3Yx_QBI3j5bHK66j7jdLra https://www.dropbox.com/s/dju4oxy1xl0lx9p/IMG_20170213_113914.jpg?dl=0 1:1 wave / full range horn - low-cut-off 69Hz (=> flat to 75-80 hz)... : https://www.dropbox.com/s/m5o5f8t40q0zs3y/2013-04-30%2018.55.29.jpg?dl=0 https://www.dropbox.com/sc/8cg55rf1iqbg812/AACEvkEcpcco7uX5lyqvwRjEa https://www.dropbox.com/sc/ijl74ifg1j2zf8v/AACvjHJ-ewPXsCl7d3oz2F9Ka https://www.dropbox.com/s/jplinwcc41zno51/11892146_10155995361270574_2751972599658977769_n%20%281%29.jpg?dl=0 ...the top four is flipped upside down, when playing :) ...: https://www.dropbox.com/sc/y2z1ai6sqon0cg4/AADIIyPKVfxOswi-Lr0yvw44a |
Posted By: Father-Francis
Date Posted: 13 February 2017 at 10:59am
hvor er du fra, er du fra havnen------------- Music is the strongest form of magic.(+45 31879997)blakmanpro@gmail.com, foa@sweetboxaudio.dk |
Posted By: AndersB
Date Posted: 13 February 2017 at 11:11am
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oprindelig fra Herlev :) ,,, har boet på nørrebro i ca 10.... Vi hilste helt kort på hinanden, inde på stengade,,, for ca. 6-7 år siden ca,,, tiden går... :) højtalerne står lidt stille for tiden, men dejligt der sker noget :) ... de 8 af dem er solgt. har fire tilbage, som måske kommer ud og lufter til sommer.... |
Posted By: Father-Francis
Date Posted: 13 February 2017 at 11:18am
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jeg bor ved forum, we should hook up boss ------------- Music is the strongest form of magic.(+45 31879997)blakmanpro@gmail.com, foa@sweetboxaudio.dk |
Posted By: AndersB
Date Posted: 13 February 2017 at 11:49am
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Fedt... Det vil jeg gerne ... de sidste 3 højtalere er kun 90 pct færdige, så det kunne være en god lejlighed til at få de sidste klar, og jeg har pt kun 1 digi amp, (med dsp) ... Jeg kan smide noget af det på en trailer, så kan vi høre det? ... du kan bare skrive når det passer dig. no rush fra min side i hvert fald :)
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Posted By: audiomik
Date Posted: 13 February 2017 at 12:13pm
Have full set of plans for the Q21 but will need time to extract them from an old PC. Otherwise do a search on here for Q21 as there is a dedicated thread on it Mik ------------- Warning! May contain Nuts plus springs, washers, screws, etc, etc. |
Posted By: bee
Date Posted: 14 February 2017 at 8:34pm
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@ Audiomik, the plans have been taken out of the public domain, I'm still happy to give them away, as long as a donation is made to the british heart foundation in Tonys Memory... the q21 plans were only ever shared to a very few people, to my knowledge the only ones every built were the ones muckerbarns had cnc cut. These were then sold and I have them in the workshop. Ill get some pics posted. ------------- https://www.elements-audio.com |
Posted By: bee
Date Posted: 14 February 2017 at 8:43pm
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this is a pic of the current 21" reflex cabs I'm running. Something I knocked up.... http://s280.photobucket.com/user/djbenwells/media/21inch_zpsmoodgpvx.jpg.html" rel="nofollow">  ------------- https://www.elements-audio.com |
Posted By: patryk1305
Date Posted: 14 February 2017 at 9:45pm
Bet they shift some air
 What drivers are those? |
Posted By: bee
Date Posted: 14 February 2017 at 10:02pm
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18 sound 21"... ------------- https://www.elements-audio.com |
Posted By: audiomik
Date Posted: 21 February 2017 at 8:56am
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Bee I too have had a recent heart attack and fully agree with a donation to British Heart Foundation as you request Mik ------------- Warning! May contain Nuts plus springs, washers, screws, etc, etc. |
Posted By: cravings
Date Posted: 21 February 2017 at 10:09am
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best wishes mik. |
Posted By: T-Ed
Date Posted: 21 April 2018 at 6:51pm
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I need something similar, Look good. Idealy id like to buy these but need a cheaper build option https://www.google.com/search?q=RCF+SUB+8005-AS&client=firefox-b&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjbg-j478vaAhWHDSwKHXT8CngQ_AUICigB&biw=1440&bih=803#imgrc=I86dfO-8vGTsaM: |
Posted By: vertx
Date Posted: 22 April 2018 at 3:32am
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I was playing around with a 21" ported design a few weeks back that might suit? Should be pretty easy to sim some alternative drivers in the enclosure. https://forum.speakerplans.com/topic101606.html" rel="nofollow - https://forum.speakerplans.com/topic101606.html ------------- www.instagram.com/translate.sound |
Posted By: sgarfa
Date Posted: 27 April 2018 at 9:43am
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hello .. I take the opportunity ... years ago I had built a prototype.. just to try .. in mdf sorry for the photo but i don't find the original....then i cut a collage from my instagram ... I was very satisfied .... 30-60hz (I should also have the smaart track), to be used under the tms4, the woofer was rcf lf21n451....  ------------- http://www.soundcloud.com/ramirez_amd" rel="nofollow - Ramirez_amd TECHNO |
Posted By: Dub Specialist Sound
Date Posted: 27 April 2018 at 2:28pm
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AQnyone know if any good for 2150? need to do some testing in boxs for thr pd ------------- Musical Roots Reggae Vibration is Life! for music is sound...sound is vibration...vibration is energy... and energy begets life. Therein lies my passion!...MUSIC IS LIFE... |
Posted By: Father-Francis
Date Posted: 27 April 2018 at 2:40pm
It will work good with both 2150&neo boss down to around 32hz
------------- Music is the strongest form of magic.(+45 31879997)blakmanpro@gmail.com, foa@sweetboxaudio.dk |
Posted By: T-Ed
Date Posted: 01 May 2018 at 7:37am
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Thanks for Replys, Looks good. Im looking for slightly smaller width, no more than 600. may have to try find a second hand one to have a look at. Im after the ported reflex design specifically. same as this https://www.google.com/search?q=RCF+SUB+8005-AS&client=firefox-b&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjbg-j478vaAhWHDSwKHXT8CngQ_AUICigB&biw=1440&bih=803#imgrc=I86dfO-8vGTsaM: I need to find the exact same design. the outside dimensions are
cheers |
Posted By: DMorison
Date Posted: 01 May 2018 at 7:19pm
Well, looks like it's time to download WinISD or similar, calculate a realistic internal volume to go with those external dimensions and model something yourself then. Remember any modelling is based on the net internal volume of a box after accounting for the driver, bracing, ports, handles etc. Remember also that a shelf port will tune lower than predicted by WinISD, so some prototyping is likely to be required. (This is because the maths used by WinISD to calculate port length assumes the internal end is well away from the side walls of the cabinet - the opposite of what happens with a shelf port.) Good Luck, David.
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Posted By: T-Ed
Date Posted: 07 May 2018 at 3:20pm
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Ok, Thanks for the advise. Is there any software you can recommend that will take into account the shelf port? so i can design accuratley from the start, i dont mind spending some money. Im going to use rcf LF21X451 drivers. Cheers
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Posted By: DMorison
Date Posted: 08 May 2018 at 2:19pm
I don't know of any software that accounts for the length change in shelf ports, but I have seen a formula for calculating the new port length yourself. It is: Lv = 10 * c^2 / (16*pi) * D^2 * Np / (fb^2*Vb)-k*D Where c = 344m/s D=diameter of vent in cm Np=no. of vents k = correction K values suggested are: 0.732 for a vent that is in the middle of the baffles ie away from any sides. 1.23 for a vent that is against one side wall only 1.728 for a corner vent 2.227 for a shelf vent that is against three internal walls of the cabinet. Here's the original image I got that from , it's been around several other audio fora for a decade or more but I don't know the original source.  |