ProSoundWeb Community

Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Subwoofer Forum => Topic started by: Onlin Barna on February 19, 2014, 06:20:44 AM

Title: Plans for this 21" 18sound speaker?
Post by: Onlin Barna on February 19, 2014, 06:20:44 AM
Hello all,

I'm looking for subwoofer plans for Eighteensound 21LW1400 type speaker. I can see only one plan by the manufacturer, that is a bandpass design, which maybe not suitable for outdoor events (anyway, I would listen everybody's opinion about this...). Here is the official plan: http://wizardaudio.hu/hasznos/hangfal%20tervek/bass/band%20pass/pdf/18Sound%20Kit21.pdf

I need a relative easy to build plan, mostly for horns because of outdoor event, but if anybody has other good plans for this speaker, please tell me.

Thank you very much
Title: Re: Plans for this 21" 18sound speaker?
Post by: Ivan Beaver on February 19, 2014, 01:21:21 PM
Hello all,

I'm looking for subwoofer plans for Eighteensound 21LW1400 type speaker. I can see only one plan by the manufacturer, that is a bandpass design, which maybe not suitable for outdoor events (anyway, I would listen everybody's opinion about this...). Here is the official plan: http://wizardaudio.hu/hasznos/hangfal%20tervek/bass/band%20pass/pdf/18Sound%20Kit21.pdf

I need a relative easy to build plan, mostly for horns because of outdoor event, but if anybody has other good plans for this speaker, please tell me.

Thank you very much
You should not be looking for speaker plans for a particular driver-but rather looking at something (driver AND plans) that meets your needs.

FIRST you have to define your needs?  Do you need low freq or high output?

Does size matter?  How simple is simple?  What sort of wood working tools do you have?  What is your skill level with those tools?

What you are asking is along the lines of "I have a small block Chevy engine-does anybody know a good car to put it in?

Without more details there is no correct answer for YOUR needs.  Somebody may have something that works for them but not you.
Title: Re: Plans for this 21" 18sound speaker?
Post by: Tim Weaver on February 19, 2014, 02:43:59 PM
Hello all,

I'm looking for subwoofer plans for Eighteensound 21LW1400 type speaker. I can see only one plan by the manufacturer, that is a bandpass design, which maybe not suitable for outdoor events (anyway, I would listen everybody's opinion about this...). Here is the official plan: http://wizardaudio.hu/hasznos/hangfal%20tervek/bass/band%20pass/pdf/18Sound%20Kit21.pdf

I need a relative easy to build plan, mostly for horns because of outdoor event, but if anybody has other good plans for this speaker, please tell me.

Thank you very much

I have a pair of these monster subs, but the box design got put on hold a while back, then I had a computer crash and lost all the data I had amassed on my design. I have a test box and was tuning the ports to find the sweet spot.

My design is going to be a "self powered" box. Basically I'm going to build a space to house an amp in the cabinet. These will be fairly tall so I can put a set of HPR153's on top as well.

What do you need the sub to do?
Title: Re: Plans for this 21" 18sound speaker?
Post by: Onlin Barna on February 20, 2014, 05:34:51 PM
You should not be looking for speaker plans for a particular driver-but rather looking at something (driver AND plans) that meets your needs.

FIRST you have to define your needs?  Do you need low freq or high output?

Does size matter?  How simple is simple?  What sort of wood working tools do you have?  What is your skill level with those tools?

What you are asking is along the lines of "I have a small block Chevy engine-does anybody know a good car to put it in?

Without more details there is no correct answer for YOUR needs.  Somebody may have something that works for them but not you.

I want it more loud then deep, but as far as I know it would be a horn subwoofer, which I don't really like. (Can't it be both: deep and loud?  ;D ;D )

My friend has connection with a CNC machine but they don't have experience in speakers, by the way I would unsay the thing I said it should be simple  :)

First I would make one piece as "hobby" and later if my budget allows, I would build 3 more with which I can go for works too (indoor and small outdoor events, 1-200 ppl max)

Size is not a problem, I will put some handles and wheels on it.

Have you looked the plan I attached? Maybe bandpass is what I need? (indoor and outdoor too)
Title: Re: Plans for this 21" 18sound speaker?
Post by: Ivan Beaver on February 20, 2014, 07:59:04 PM
I want it more loud then deep, but as far as I know it would be a horn subwoofer, which I don't really like. (Can't it be both: deep and loud?  ;D ;D )


Sure subs can be loud and deep.  It depends on what you consider "loud" and "deep".

Why don't you like horns?  You can get the most SPL for the lowest cost that way.  IF designed right.
Title: Re: Plans for this 21" 18sound speaker?
Post by: Onlin Barna on February 21, 2014, 12:05:33 PM
Sure subs can be loud and deep.  It depends on what you consider "loud" and "deep".

Why don't you like horns?  You can get the most SPL for the lowest cost that way.  IF designed right.

I don't like horns because which I heard (not one) I didn't like their sound. And also, it felt like they aren't really "punch in my stomach" enough. But maybe - probably - I have had experience with wrong built or just bad horn subwoofers.

If somebody makes me a good horn subwoofer (which maybe will have more then 100dB sensitivity?  :o :) ) It would be great. Manufacturer data: http://www.eighteensound.com/index.aspx?mainMenu=view_product_simple&pid=196
Title: Re: Plans for this 21" 18sound speaker?
Post by: Tim McCulloch on February 22, 2014, 12:03:18 PM
I don't like horns because which I heard (not one) I didn't like their sound. And also, it felt like they aren't really "punch in my stomach" enough. But maybe - probably - I have had experience with wrong built or just bad horn subwoofers.

If somebody makes me a good horn subwoofer (which maybe will have more then 100dB sensitivity?  :o :) ) It would be great. Manufacturer data: http://www.eighteensound.com/index.aspx?mainMenu=view_product_simple&pid=196

The "punch" in LF comes from mid-bass, not subwoofer frequencies.  Reflex loaded cabinets typically have much higher 2nd & 3rd harmonic distortion than horn loaded subs (often more distortion products that the fundamental frequency that generates them), and that distortion is often the punch that users identify.  My previous employer called distortion "free dB's" which, while they may be included at no extra cost, do not represent the signal being applied.

If you do not already own the 21" speaker in question, I'd suggest waiting until you find a design that either is "correct" or serves your uses, whichever is more important to you.

That said, size does not matter (other than to your spouse... ).  Competent designs exist for sub woofer systems that use a wide variety of loudspeaker sizes.  21" may give you bragging rights but if the sound sucks, does it matter?
Title: Re: Plans for this 21" 18sound speaker?
Post by: Ivan Beaver on February 22, 2014, 12:39:25 PM
I don't like horns because which I heard (not one) I didn't like their sound. And also, it felt like they aren't really "punch in my stomach" enough. But maybe - probably - I have had experience with wrong built or just bad horn subwoofers.

If somebody makes me a good horn subwoofer (which maybe will have more then 100dB sensitivity?  :o :) ) It would be great. Manufacturer data: http://www.eighteensound.com/index.aspx?mainMenu=view_product_simple&pid=196
Then you have not been listening to properly designed horns or systems that have not been setup properly.

Generally the problem with horns is lack of deep bass-unless they are really large.

As a general rule-horns have much more "punch" than front loaded cabinets-because at the upper end of the response there is a lot of "horn loading" going on-which means those freq are going to "kickout" a good bit more.
Title: Re: Plans for this 21" 18sound speaker?
Post by: Tim McCulloch on February 22, 2014, 12:46:26 PM
Then you have not been listening to properly designed horns or systems that have not been setup properly.

Generally the problem with horns is lack of deep bass-unless they are really large.

As a general rule-horns have much more "punch" than front loaded cabinets-because at the upper end of the response there is a lot of "horn loading" going on-which means those freq are going to "kickout" a good bit more.

I think you glossed over the distortion components of reflex loaded subs.  The 2nd & 3rd harmonics will be louder than the fundamental frequencies in the program material, especially when the rig is pushed (and most subs are pushed hard).  I know you know this, Ivan, and low distortion horn are part of what you guys do at Danley.  I've heard several comments about Danley subs that *complain* about the lack of distortion because the listeners are soooo accustomed to hearing it they believe it's really part of a designer's intentions, rather than an unfortunate artifact about which little can be done.
Title: Re: Plans for this 21" 18sound speaker?
Post by: Ivan Beaver on February 22, 2014, 01:15:00 PM
I think you glossed over the distortion components of reflex loaded subs.  The 2nd & 3rd harmonics will be louder than the fundamental frequencies in the program material, especially when the rig is pushed (and most subs are pushed hard).  I know you know this, Ivan, and low distortion horn are part of what you guys do at Danley.  I've heard several comments about Danley subs that *complain* about the lack of distortion because the listeners are soooo accustomed to hearing it they believe it's really part of a designer's intentions, rather than an unfortunate artifact about which little can be done.
It is really funny to me when people say they want a system that is "accurate" and "reproduces the input signal", yet they think that systems that are distorted and far from flat response are somehow "right".

You CAN NOT have a system that is accurate and yet distorts/changes the signal at the same time.

Part of the problem is that people are so used to hearing systems that are not accurate-that they believe what they are hearing is "correct".

To me the PA system should be very linear and accurate.  You leave the "voicing of the sound" to the guitar amp speakers and such.  It should reproduce what goes in.

And there are many systems that "say" they do that-yet are far from it.

And for what it is worth-the loudspeaker is by far the worse reproducer of a signal than anything else in the chain.  And NO loudspeaker is truly accurate.  When a cone moves-it introduces distortion (not just harmonic but other "distortions" of the signal).

But we can try to get them as accurate as possible.  The more a cone "flops around" the more distorted it will be.  And that is why horns have such lower distortion-for a couple of reasons.

First they control the movement of the cone more-so it is "flopping around" less.

Second the horn adds gain to the signal-so for the same amount of "power" the horn is louder-which means to get the same loudness you don't have to turn it up as much-so there is less distortion.

And with most of the Danley full range cabinets, we have an "acoustic distortion reducer" on them.  That what the little holes in front of the woofer and mids do. 

They act as acoustic low pass filters-which reduce the distortion components in level-so the sound is clearer.

OF course a clearer sound is not always good.  You start to hear all the defects in the source.  But with a good source you hear things you didn't before-because there is less distortion to "get in the way".

I have had a number of people over the years say this "I want it to sound like me-just better".  So EXACTLY HOW am I supposed to do that????????????
Title: Re: Plans for this 21" 18sound speaker?
Post by: Tim Weaver on February 23, 2014, 06:56:56 PM
From my earlier design I figured that one 21LW1400 in a good box would be *almost* equal to an SRX728 in regards to efficiency and maximum CLEAN output. You can push the 728 quite a bit harder into the badlands of distortion, power compression, and voice coil burnage. But apples to apples the 18 sound driver would hold it's own just fine.

I'm not sure this driver would be worth it to put in a horn anyway. It would have to be a huge horn to do any good at all. The 21LW1400 will play nicely into the mid 30's in a reasonable sized box.
Title: Re: Plans for this 21" 18sound speaker?
Post by: Onlin Barna on February 23, 2014, 08:23:57 PM
Thanks for all the replies, its great that people can always learn here. :)

By the way,  I haven't bought the speaker yet. I am also considering 18LW1400. Its almost half price so I could get double pcs for the money. (First 1 or 2 then 4 or 8 pieces)

I have found only one plan for that speaker: http://wizardaudio.hu/hasznos/hangfal%20tervek/bass/bass%20reflex/pdf/18Sound%20Kit18%20B.pdf

But if you have or can make a horn plan for it, Im interested!
Title: Re: Plans for this 21" 18sound speaker?
Post by: Peter Morris on March 31, 2014, 01:11:30 AM
Thanks for all the replies, its great that people can always learn here. :)

By the way,  I haven't bought the speaker yet. I am also considering 18LW1400. Its almost half price so I could get double pcs for the money. (First 1 or 2 then 4 or 8 pieces)

I have found only one plan for that speaker: http://wizardaudio.hu/hasznos/hangfal%20tervek/bass/bass%20reflex/pdf/18Sound%20Kit18%20B.pdf

But if you have or can make a horn plan for it, Im interested!


FWIW I have a very similar box (220L @ 35Hz) load with the 21LW1400. Its sounds great, everyone that’s uses it just loves the sound.  I have also use the 18Lw1400 in that box - in comparison the 21 goes, as a guess, about 4dB harder with similar input and sounds a little better.  The extra output isn’t apparent until you start to push the level up.
Title: Re: Plans for this 21" 18sound speaker?
Post by: Tim Weaver on March 31, 2014, 01:29:05 PM
Thanks for all the replies, its great that people can always learn here. :)

By the way,  I haven't bought the speaker yet. I am also considering 18LW1400. Its almost half price so I could get double pcs for the money. (First 1 or 2 then 4 or 8 pieces)

I have found only one plan for that speaker: http://wizardaudio.hu/hasznos/hangfal%20tervek/bass/bass%20reflex/pdf/18Sound%20Kit18%20B.pdf

But if you have or can make a horn plan for it, Im interested!


OK, since you seem to be thinking that "Larger=Louder" I'll explain the problem to you in a pretty simple way. Horns put a LOT of stress on a cone driver. A bigger 18" or 21" cone simply can't resist the bending forces inside a horn's compression chamber as easily as a 12" or smaller cone can. That's why you see a bunch of horn sub designs with 12" drivers in them. As of today's technology the 12" sized driver has a strong enough cone, and is big enough to mount a strong motor to the frame which results in the best candidate for a horn driver.

In a horn, the speaker is like an engine in a car. There are many other factors that play into how loud the system gets. The size of the driver is just not that important when you factor in all of the other things.


In a bass reflex cabinet, the amount of air displaced by the driver is the biggest factor in how loud it can get. That's why we see 18"'s and 21"'s in standard BR cabinets. The huge cones sweep a lot of air. A 12" driver would have to move in and out about 4 times as much as an 18" to sweep the same volume of air.
Title: Re: Plans for this 21" 18sound speaker?
Post by: Peter Morris on April 01, 2014, 10:59:56 AM

OK, since you seem to be thinking that "Larger=Louder" I'll explain the problem to you in a pretty simple way. Horns put a LOT of stress on a cone driver. A bigger 18" or 21" cone simply can't resist the bending forces inside a horn's compression chamber as easily as a 12" or smaller cone can. That's why you see a bunch of horn sub designs with 12" drivers in them. As of today's technology the 12" sized driver has a strong enough cone, and is big enough to mount a strong motor to the frame which results in the best candidate for a horn driver.

In a horn, the speaker is like an engine in a car. There are many other factors that play into how loud the system gets. The size of the driver is just not that important when you factor in all of the other things.


In a bass reflex cabinet, the amount of air displaced by the driver is the biggest factor in how loud it can get. That's why we see 18"'s and 21"'s in standard BR cabinets. The huge cones sweep a lot of air. A 12" driver would have to move in and out about 4 times as much as an 18" to sweep the same volume of air.

Hi Tim,

I think that was certainly true of old driver designs, but there are lots of 18” even 21” drivers that are now suitable for horn loading.
Here's a new one from 18sound - http://www.eighteensound.com/PRODUCTS/Products/ProdID/63/CatID/8#.UzrTfWkbrq4

@ Onlin here is a horn design for an 18sound driver like the one you mentioned - http://www.eighteensound.com/Portals/0/EnclosuresKits/18sound_18%20horn%20loaded.pdf
Title: Re: Plans for this 21" 18sound speaker?
Post by: duane massey on April 01, 2014, 06:13:55 PM
Interesting. In the full-size straight horns I have built over the years I found pretty much the opposite to be true as far as stress goes. In the biggest horns I've ever built (20hz horn w/ 5 15" woofers) one of the biggest surprises for most people who were brave (or foolish) enough to venture all the way into the horn was how little cone movement there was.
I can certainly see where smaller folded horns could be problematic, but I typically neither design or build these.