Plans for RCF dual 18"
Printed From: Speakerplans.com
Category: Plans
Forum Name: Plan Requests
Forum Description: All plan requests here
URL: https://forum.speakerplans.com/forum_posts.asp?TID=96054
Printed Date: 27 March 2026 at 12:52am
Software Version: Web Wiz Forums 12.08 - https://www.webwizforums.com
Topic: Plans for RCF dual 18"
Posted By: djteknovibe
Subject: Plans for RCF dual 18"
Date Posted: 21 June 2016 at 7:16pm
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Does anyone have any plans or know how to design a decent front baffle reflex loaded enclosure? I'm wanting to make a decent enclosure design for two RCF LF18X451 loaded dual 18" bass reflex. I want the enclosure to be such that the drivers perform so ideally if possible they'll be about -3db down at about 35hz. Here's the driver i'm wanting to use : http://www.rcf.it/en_US/products/precision-transducers/low-frequency-transducers/lf18x451" rel="nofollow - http://www.rcf.it/en_US/products/precision-transducers/low-frequency-transducers/lf18x451 I'm absolutely useless at designing enclosures so I thought i'd ask you guys seeing as a lot of you guys design and build your own enclosures. |
Replies:
Posted By: sn95
Date Posted: 22 June 2016 at 6:38pm
| A 7ft /198l tune to 36 Hz deals the flattest response that I could get and will still take 1400 before hitting Xmax so 198l per driver . |
Posted By: djteknovibe
Date Posted: 22 June 2016 at 6:50pm
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So a 198 litre enclosure tuned to 36hz would be ok, thanks, but how come the drivers would nly be able to take 1,400 watts each? They're rated at 1,800 watts rms continuous. |
Posted By: sn95
Date Posted: 22 June 2016 at 7:02pm
| At Xmax .you will need to add a little eq at 60 Hz . |
Posted By: djteknovibe
Date Posted: 22 June 2016 at 7:09pm
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Add a little? Not take a few db off? Ok thanks, how accurate is the software you use anyway? Plus how would I go about getting the enclosures made? obviously i'd need to add internal volume because of bracing, drivers and stuff right? |
Posted By: sn95
Date Posted: 23 June 2016 at 12:26am
| Add a little .I'm using WInisd pro .have you looked at the B&C 18tbx100 it looks good and a little smaller box and flatter response . |
Posted By: djteknovibe
Date Posted: 23 June 2016 at 9:28am
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I'd rather use the RCF LF18X451 as it'll overall give me 4-5db more spl output in a dual 18" box than using the B&C 18TBX100. I have no idea how I actually go from here to getting the enclosures for the RCF drivers designed and made. How would I go around that? I know what I want thr enclosures to look like, I want rectangular slot ports, a black duraflex style paintwork finish, steel powder coated grille that's flush with the front of the enclosure. I want speakons on the back, steel or very hard plastic handles. |
Posted By: MarjanM
Date Posted: 23 June 2016 at 12:22pm
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How do you calculated that RCF will give you 4-5db more spl then tbx100? They are more or less equal in sensitivity. 1200 to 1800W is aproximately 1.5db. You might have more difference at 40hz but not above. ------------- Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713 |
Posted By: djteknovibe
Date Posted: 23 June 2016 at 1:27pm
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I meant to say 3-4db extra spl output and also because i'll be using two drivers in each enclosure and that adds up to about 3db extra spl output in total. |
Posted By: Teunos
Date Posted: 23 June 2016 at 1:28pm
More power, more linear displacement and less power compression. Also, RCF has a higher BL/Re gives a stronger motor. I'd take the RCF any day of the week over the B&C. ------------- Best regards, Teun. |
Posted By: djteknovibe
Date Posted: 23 June 2016 at 1:31pm
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How do I go about getting these enclosures made? |
Posted By: DMorison
Date Posted: 23 June 2016 at 1:48pm
If you can't design and build it yourself, you'll need to pay someone to do it for you. Maybe post in the Wanted fourm?
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djteknovibe wrote:Posted By: djteknovibe
Date Posted: 23 June 2016 at 3:35pm
| I'm currently looking at the idea of getting a professional cabinet maker to build me two G Subs loaded with RCF LF18X451 drivers but someone has said the ports might not be big enough because the LF18X451 drivers move a hell of a lot of air. I don't know the internal volume of the G Subs (taking off for braces etc..) though so I can't calculate how long or big the ports in the G Subs would need to be. |
Posted By: MarjanM
Date Posted: 23 June 2016 at 3:58pm
That still aint going to make it 4-5db louder. ------------- Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713 |
Posted By: djteknovibe
Date Posted: 23 June 2016 at 4:06pm
| Like i've said I mean 3db. |
Posted By: sn95
Date Posted: 23 June 2016 at 4:23pm
| The reason I mention the TBX is because it models flatter than X 451 |
Posted By: nickyburnell
Date Posted: 23 June 2016 at 5:37pm
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Gsub with all that baffle inside aint big enough. I'd start with the below and get used to sims. Having said that if you leave those triangle ports un-glued you should be able to play with various lengths by ear and choose what suits? http://www.fane-international.com/downloads/Fane%20EN21802%20Enclosure.pdf" rel="nofollow - http://www.fane-international.com/downloads/Fane%20EN21802%20Enclosure.pdf ------------- It's everything, not everythink! |
Posted By: djteknovibe
Date Posted: 23 June 2016 at 9:48pm
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Thanks but I want the RCF LF18X451 drivers in a dual 18" sub not Fane. |
Posted By: djteknovibe
Date Posted: 23 June 2016 at 10:19pm
I put it into WinISD and tried it with two RCF LF18X451 drivers in a G Sub, I adjusted the port width to 102mm instead of the 120mm width on the original G Sub plans and aport length of 221mm instead of the 193mm of the original G Sub plans. This below is the frequency response it gave me, box tuning 35hz and is -3db down at 38.5hz. |
Posted By: djteknovibe
Date Posted: 23 June 2016 at 10:21pm
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Oh and the spl output with 3,600 watts continuous put into the sub with the two drivers is 132db at 37hz. |
Posted By: sn95
Date Posted: 24 June 2016 at 12:30am
| Look at your port velocity. |
Posted By: djteknovibe
Date Posted: 24 June 2016 at 10:47am
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I've tried and can't get the velocity much lower than that at all. Couldn't I just add a bit more to the internal volume of the enclosure that way I could increase the port size. I worked out as standard the G Sub has an internal volume of about 265.3 litres. |
Posted By: toastyghost
Date Posted: 24 June 2016 at 11:44am
| Those results aren't great in terms of SPL or cutoff frequency to be honest. |
Posted By: djteknovibe
Date Posted: 24 June 2016 at 12:01pm
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I give up it's too overwhelming, I struggle to get it all through my head. |
Posted By: sn95
Date Posted: 25 June 2016 at 3:29pm
| Don't give up yet mush like anything in life at appears to be simple at the beginning but it's not .if you are wholeheartedly sit on using that driver maybe look in to a tapped horn I think there are 2 or 3 plans that may be suitable for the x451 . |
Posted By: djteknovibe
Date Posted: 25 June 2016 at 8:13pm
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I'm absolutely dead set on using that driver I just thought seeing as it's rated at 18,000 watts AES and has a 13.5mm xmax figure that two in an enclosure would give some serious bass. I don't know anyone that could say for definate that the driver could be excellent in a horn or what horn and I don't know anyone that could make the horn enclosures for me. I ideally wanted two dual 18" enclosures to give me some serious powerful sub bass. |
Posted By: Pbg
Date Posted: 26 June 2016 at 3:09am
| For the amount you're insisting on spending on drivers, why not spring a little more on a saw, a straight edge, and a screwgun? Building a box is the easy part. Knowing what you actually want and designing one that does it is the trick. |
Posted By: djteknovibe
Date Posted: 26 June 2016 at 9:13am
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Nah i'm absolutely useless at carpentry. |
Posted By: toastyghost
Date Posted: 26 June 2016 at 2:54pm
| Then since you're paying for premium drivers budget for premium built boxes. Plenty of builders out there and a reflex cab is usually easier to knock out. |
Posted By: djteknovibe
Date Posted: 26 June 2016 at 6:42pm
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I don't know any though |
Posted By: nickyburnell
Date Posted: 26 June 2016 at 8:41pm
I can read. The box is just wood, not Fane wood  . The idea was as a big enough box for you to start from then play with ports to get to your goal------------- It's everything, not everythink! |
Posted By: DMorison
Date Posted: 26 June 2016 at 9:02pm
So, you haven't even googled "UK Speaker Builders"? Copypasta this into a new post in the "Wanted" section (everything in bold you have to do yourself): Subject: Design, Build & Deliver 4 off single/ 2 off dual (delete as applicable) 18 BR to be loaded with LF18X451 Message: Preferred frequency response: XXHz to YYHz (-3dB) Maximum dimensions: xxx by yyy by zzz mm Material: 18mm Baltic Birch. Finish: Warnex or equivalent Grille required: 1.6mm steel, powder coated, min 60% open area Handles required: <insert your requirements here> <any other requirements you have go here> Just be prepared to give your wallet some exercise
 |
Posted By: djteknovibe
Date Posted: 26 June 2016 at 9:21pm
| At the moment I haven't got the money I just wanna get a price for two enclosures for the drivers amd see how much people might charge |
Posted By: cookie-dj
Date Posted: 26 June 2016 at 9:52pm
 ------------- You can't polish a turd! |
Posted By: djteknovibe
Date Posted: 27 June 2016 at 11:24am
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I'm saving up the money and definately wanna buy some subs or get enclosures made but I have no idea what the cost of enclosures being made would cost me. |
Posted By: nickyburnell
Date Posted: 27 June 2016 at 3:03pm
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So you don't want to learn how to use sims You don't want to learn how to do carpentry. You have no money. People have been trying to help, spending their time. Perhaps some more background on you? Age, job, background in PA or Music? ------------- It's everything, not everythink! |
Posted By: djteknovibe
Date Posted: 27 June 2016 at 3:09pm
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So you're jumping to conclusions? *rolls eyes*. I never said I don't wanna learn how to use design software I am trying so gimme a break. I never said I don't wanna learn carpentry either so stop putting words in my mouth mate. I said i'm useless at carpentry. What's my age and job got to do with me wanting two dual 18" subs? I know a bit about sound systems like what power comrpession is, what RMS actually is (voltage not watts like people think), I know quite a bit but not a hell of a lot, if that makes any sense. |
Posted By: rish
Date Posted: 27 June 2016 at 3:22pm
Sorry cookie-dj, I just had to repost your pic...... after reading this tread. Rish
|
Posted By: djteknovibe
Date Posted: 27 June 2016 at 4:05pm
| Rish, if you haven't got anything to add apart from that stupid f**ing picture then don't bother. |
Posted By: sn95
Date Posted: 27 June 2016 at 11:40pm
| Ok so today I had some time to play around with x451 some more and came up with the following box modeled after the Gsub but a little bigger 16.398 or 464.33 L tune to 33hz .The outside is 1220x610x711 using 24mm ply and the will be 562x 175x505 and a port velocity of 23.5 m/s . It can take 3k at Xmax and will produce 127.7 /30hz and from 40to 100 / 132Dbs .also don't take to hard it's just a joke. |
Posted By: sn95
Date Posted: 27 June 2016 at 11:57pm
| http://www.diyaudio.com/forums/attachments/subwoofers/555769d1466426396-keystone-sub-using-18-15-12-inch-speakers-18x451.png" rel="nofollow - http://www.diyaudio.com/forums/attachments/subwoofers/555769d1466426396-keystone-sub-using-18-15-12-inch-speakers-18x451.png You may want to look at this. |
Posted By: djteknovibe
Date Posted: 28 June 2016 at 8:21am
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A joke is one thing but purposely spamming the thread is annoying, I can't look at that DIY forum i'm not a member and all I get is a log in page come up. Thanks for the help with the G Sub design, the port velocity is extremely high isn't it've been reading about port velocity and i've read anything above 0.10 causes port noise. |
Posted By: sn95
Date Posted: 28 June 2016 at 11:43am
| The port velocity I'm getting is 23m/s at 3k.but the port can be made big to lower the velocity. By go to a 200mm it go down to 20m/s . |
Posted By: djteknovibe
Date Posted: 28 June 2016 at 1:55pm
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But 20m/s is still a hell of a loud port noise. When I was using the original G Sub plans as a design the port velocity I got down to 0.16. |
Posted By: sn95
Date Posted: 28 June 2016 at 2:05pm
| What was your Watt input? |
Posted By: djteknovibe
Date Posted: 28 June 2016 at 4:10pm
| I can't remember if it was 1 watt or 3,600 watts because that's the combined power of two RCF LF18X451 drivers and in WinISD I did select two drivers so... |
Posted By: djteknovibe
Date Posted: 28 June 2016 at 4:14pm
| Just checked WinISD just now and yeah it was at 3,600 watts and the port velocity is 0.16 it says. |
Posted By: sn95
Date Posted: 28 June 2016 at 4:58pm
| Just for comparison I input the Gsub port and 3k it's at 42m/s so either I'm putting some input wrong are you are .I will recheck my input . |
Posted By: djteknovibe
Date Posted: 28 June 2016 at 5:35pm
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In the menu where it says 'Driver', 'Box', 'Plot', 'Project' I selected the 'Plot' tab and input 3600 into the 'Power' box. |
Posted By: sn95
Date Posted: 28 June 2016 at 5:40pm
| Signal |
Posted By: djteknovibe
Date Posted: 28 June 2016 at 5:51pm
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Here's a screenshotI edited to be able to show you multiple settings in the tabs in WinISD including the frequency graph. http://postimg.org/image/x6dld511d/" rel="nofollow - http://postimg.org/image/x6dld511d/ |
Posted By: sn95
Date Posted: 28 June 2016 at 6:29pm
| .16 mark is 53m/s |
Posted By: sn95
Date Posted: 28 June 2016 at 6:29pm
| Are you using WINisd pro ? |
Posted By: djteknovibe
Date Posted: 28 June 2016 at 6:33pm
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No i'm using WinISD Beta, I tried the pro one but couldn't understand how to use it, it was kind of overwhelming. SN95, ah ok mate. |
Posted By: DMorison
Date Posted: 28 June 2016 at 7:57pm
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So what you're telling us is that you’re willing to post here 45 times over the last week, and spend most of £1200 on drivers (never mind the cabs to put them in) but not take the couple of minutes to sign up over there? Comments like
this, and your recent one about not knowing any cab builders, can easily be
interpreted as you not putting in much effort - and you'll always get more
people willing to help you if you show that you are in fact willing to put in the
effort.
Yup, that’s why SN95’s version has a bigger port than the original G-Sub (983.5cm2 vs 556.8 cm2) – putting drivers this powerful in the original would indeed push the airspeed too high. If SN95’s proposed vent size gets you to 23ms-1 (≈ M 0.07), I wouldn’t worry too much. (Just in case there’s still any confusion, “Vent Mach” in WinISD Beta is telling you what proportion of the speed of sound (343ms-1, give or take for variance in atmospheric pressure & temperature etc) you have; so Mach 0.1 is an airspeed of about 34ms-1.) |
Posted By: djteknovibe
Date Posted: 28 June 2016 at 8:12pm
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Ok if you think i'm not bothered to put in any effort then what's the point, i'm trying the best I can to understand WinISD and I wasn't a member of that site and didn't have time at the time to join. I've got two kids to take care of and post a quick reply when I can. But ok if you think i'm wasting my time then forget it bye |
Posted By: Teunos
Date Posted: 28 June 2016 at 8:54pm
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You do understand that in a forum everybody is equal to share information and discuss? Everybody on here is sharing because they like to share. Me typing this is offering op some time just because i feel like sharing. That goes the same for everybody else on this topic, even when you might not like what they have to say. So ignore what you do not what to hear and focus on what you think is important. We can all simply choose not to reply, and you wont get any further. Instead we already shared a lot of information here, and links to where more information can be found. What you do with that is up to you. If i set up a thread asking a question or some topic i would like some feedback on, and i get this ratio of reads/replies i would be a happy camper.
------------- Best regards, Teun. |
Posted By: DMorison
Date Posted: 28 June 2016 at 9:36pm
OK, lets get this straight, nobody's going to criticize you for putting family first, that's completely commendable - but if that's the real reason you couldn't check the link, then there was no point putting a completely different reason in your post. Hell, if you were tight for time, you didn't really need to mention it at all - just file the link away to catch up with later and move on. No one here will be offended if you don't acknowledge every suggestion immediately. Also, the point of mentioning it was to point out a way of you getting more out of being here - that shouldn't be any reason to leave. |
Posted By: cookie-dj
Date Posted: 28 June 2016 at 11:18pm
+1 Also, having 3-4 different threads with the same outcome doesn't help- people with a wealth of experience are trying to help you in all threads but you choose not to take any advice... a lot of us have said spending £1200 on powerful horn drivers for reflex cabs isn't a great idea....hence why its taking you SO long to find a SIMPLE reflex cab for your requested driver. Hey its your money at the end of the day, looking at possibly 2k inc drivers and completed cab building. Hell of a lot of money for 2x homebrew 218's. When you do come to completing the cabs, we will all still be here to drool over woodworking pics (we do love a good build thread here) ------------- You can't polish a turd! |
Posted By: Sound Chippy
Date Posted: 02 July 2016 at 11:48pm
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Sorry this might not seem that constructive to the original question or possibly someones ego ..... I love tekno but your Vibe and approach is shit mate. I love this forum and for most the majoritity of the folk on here who offer their knowledge, of their own occurd to help people like you with years of experiance behind their words, sound advice acquired by investing not a couple lil google searches but a shit load of time, not to mention the financial outlays that have come with that wisdom, by making choices to the best of there ability in that moment, some wise or some not or stumbled on a bargain or like most of us can reflect back and cringe at some things we either built or purchased but fuk it we hopefully gained a greater understanding of how shit works in the process. Gaining an understanding of the mechanics of sound reproduction thru experiences.. invaluable. No ones be handed this info of their Mums tits but if you want to be breast fed or not go away and do some research regarding there advice ... or get so hung up on specs and manufacture waffle . In the diy spirit can I offer my humble advice I wanna help you and I am sure most will agree to achieve the result your after for your application while factoring in budget. I wish i had been told this first but go buy some quality water resistant mdf, can pick that up for a good price if ya hunt around .. grab a mate ...cheap saw .. a drill... screws ...a straight edge and probably some polyurethane glue as I find user friendly .. especially if there your first cabs.. easy to wipe off any excess and plenty of time on ya side ..forgiving on any inaccuracy with cuts as well. Then for cab coating get 2 kilo off beetroots .. cheap... cut into 1cm cubes bring to boil then simmer for 2hrs in 10 litres of water .. cool .. disregard beetroot cubes then add 4 ltr of pva glue or kraft glue ..cheap bro from local hardware. mix well ...makes 14 litres of prime cab coating for all weathers. Apply generously inside and outside of cab. Allow 24hrs btw coats which you will easily get 2-3 possibly more with that amount... No sanding either ...will be plenty those two subs. Now you have two very solid cabs that are purple. You will get more money on your hire outs this way.. trust me it works and looks pro, I have used it on and off for along as i can remember, never had a call back. Another great attribute to the properties of cab coating is this....go grab ya mate or mum and stand back in sweet spot as you would in testing and you will get this profound almost unexplainable yet most noticeable boost in db around the 35htz absolutely krazy ...trousers will be flapping due to that rock hard texture finish from that specific cab coating.. less friction .. more throw ...better penetration.. and one big grin from one ear to ear.... on you ..ya mate and ya mum :) btw I don't think purple makes ya subs sound any different, some swear by it but this shit works ... plus purple cabs are sexy....You don't even need to use google now ..
i remember what it was like starting out n all.. overwhelming ... . Now go and build those cabs and enjoy ya tekno ....happy to help ...pm for further advice ... build pics if ya can |