I'm thinking about building a subwofer for my HT system and music.
I chose this speaker because I can buy it here in Argentina, and I think it will be a good complement to a Dayton SPA250 board amplifier.
Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier
http://www.18sound.it/Portals/0/PDFs/18LW1400.PDF
But, I do not decide on the choice of cabinet.
As a manufacturer's recommendation, we do not have a 100% horn design available for this model.
http://www.18sound.it/Portals/0/EnclosuresKits/18H_v1.pdf
But there is a design that I do not know how to call it
It is a TL, a folded Horn, a labyrinth.? The only sure thing seems to be that it is not sealed ..
(Infinite baffle)
http://www.18sound.it/Portals/0/EnclosuresKits/18Sub_v1.pdf
270 liters is too much for my room, but I have no experience in design programs, if someone suggests me something smaller without sacrificing extension in bass I would be very grateful ... or maybe they can calculate it.
I will also gladly listen to any objection...
I chose this speaker because I can buy it here in Argentina, and I think it will be a good complement to a Dayton SPA250 board amplifier.
Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier
http://www.18sound.it/Portals/0/PDFs/18LW1400.PDF
But, I do not decide on the choice of cabinet.
As a manufacturer's recommendation, we do not have a 100% horn design available for this model.
http://www.18sound.it/Portals/0/EnclosuresKits/18H_v1.pdf
But there is a design that I do not know how to call it
It is a TL, a folded Horn, a labyrinth.? The only sure thing seems to be that it is not sealed ..
(Infinite baffle)
http://www.18sound.it/Portals/0/EnclosuresKits/18Sub_v1.pdf
270 liters is too much for my room, but I have no experience in design programs, if someone suggests me something smaller without sacrificing extension in bass I would be very grateful ... or maybe they can calculate it.
I will also gladly listen to any objection...
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I will also gladly listen to any objection...
Hey, are you really want to use 18" indoors for personal listening?
Showed TH and bass reflex designs are designed for sounding indoors at a small to medium events for about 50-200 persons and huge overkill for personal use.
If you really want to continue i could provide needed calculations for sealed box, bass reflex and bandpasses.
Hi BesPav
Look at this, you do not need to understand Spanish.
Just watch the photos.
Subwoofer de referencia con WAF de referencia
This person has a listening room much smaller than mine, and although I have not been able to listen to this system, I have heard similar things and the sound of very low frequencies is absolutely irreplaceable with other means.(Read commercial speakers Home Theater)
With a large surface of the speaker cone (SD) it is much easier to have very clean bass, without distrosion, than with speakers of small size (between 8 to 10 inches) but large Xmax. The distortion goes up a lot and it is generally necessary to amplifiers of great powers,to move the cone a lot and achieve high SPL.
As this 18 sound driver has a lot of sensitivity, in a generous volume box I think it will be unbeatable to generate the first two octaves. 0 to 40 cycles, first octave, 40 to 80 cycles is second octave .
The rest of the frequencies above do not interest me..
You know: Do Re Mi Fa SoL La Si Do , is a complete octave, the second octave is double the frequency and so on.
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That would be very appreciated by me
, take your time, just in October I will receive the plate amplifier. Thanks again !
Hi academia50,
Please post in English. You can post in other languages as long as you also have an accurate English translation in the same post.
lisoformio,
Don't you think you might need the T-S parameters in order to say anything intelligent about what box a speaker should go into? You should list those with your suggestion for a box.
-Chris
Don't you think you might need the T-S parameters in order to say anything intelligent about what box a speaker should go into? You should list those with your suggestion for a box.
-Chris
Yes... The Subwoofer DIY Page - Ported Systems: Box Calculations
Using that equations you get an internal volume around 110 liters and a tuning frequency around 40Hz.
I know, my friend, i know.
There are much more parameters than only distortion. Bass response could have good pressure, but bad timing release, good attack, but huge delay and so on. All of these are strictly depend of T-S parameters of the driver and box optimisation.
No generous, lisoformio are right.
18LW1400 are low-Q driver, so you must use it in the box 1/3-1/4 of the Vas.
Otherwise you will have undampened driver, i.e. fast attack and slow release. Bass response will be like a stretched-echoed-delayed in time.
Yes, this is good enough for bass-optimized bass-reflex design even with a more powerful amplifier.
Ok, todays evening i will show the most of.
First of all - beware of the fake 18LW1400
?????????? Eighteen Sound (18 Sound)
Good italian drivers must have green label, not white-black (most probably indicates cheap china fake).
If you have any doubt - measure Fs of the cold driver. Genuine will have something near 34-36 Hz, cheap fake - 42-48 Hz.
For Butterworth Q - approximately 48 L.
But why use sealed box without damping?
Plywood is more expensive and heavier than sintepone/flannel/felt...
It is just a duct tuned bass reflex. Based on published specs, a classic alignment is ~206 L tuned to Fs, though a T/S max flat alignment would be 128 L tuned to ~47 Hz.
An EBS alignment would be ~297 L tuned to ~22 Hz, though tuning it to the THX 20 Hz reference is OK too, which would be the best overall performing in a typical room as its gradual roll-off tends to blend better with any room gain same as a low Qtc sealed alignment.
Of course you can shrink it, but the bass output will obviously be lower due to the higher F3, etc..
Still, if you don't shrink it too much it is still the best overall compromise IME with numerous low QT drivers, not the least of which is my dual Altec 515B [0.2 Qt] 'subs' tuned to ~14 Hz.
So, what is the largest dimensions you can tolerate?
GM
Thank you very much BesPav ! Very good and great work, and very fast !
Here a new find, direct from the manufacturer.
http://wizardaudio.hu/hasznos/hangfal tervek/bass/bass reflex/pdf/18Sound Kit18 B.pdf
The construction is much simpler than the previous one that I had already posted :
http://www.18sound.it/Portals/0/EnclosuresKits/18Sub_v1.pdf
But it does not appear in the current page Eighteen Sound ....
All are 297 liters, big chance...
This article is incomplete, a 95-liter loaded horn .... interesting, I'll explore, maybe serve.
Horn Subwoofer
I repeat that I look for the first two octaves, the upper basses and I have them in the DTQWTII.
20 -80 hz +/- 6 db is asking too much with VAS no more 150 lts ?
Thank you very much BesPav ! Very good and great work, and very fast !
:beer:
I repeat that I look for the first two octaves, the upper basses and I have them in the DTQWTII.
20 -80 hz +/- 6 db is asking too much with VAS no more 150 lts ?
You couldn't get good efficiency at 20 Hz from the driver with Fs~30 Hz.
The one chance - huge low-tuned box, but in this case you will be stopped very fast by cone displacement.
There are nothing for free, only tradeoff.
Choosed 18LW1400 is a high-sensitivity driver and it was optimized for providing very high listening levels outdoors or in huge premises like concert halls or stagiums.
Taking in advance room gain at low frequencies and moderate listening level at living conditions you better to assemble 150 Liter bass reflex tuned around 38-42 Hz.
Next you must provide good digital processing either with something like DBX Driverack, Behringer DCX2496 or software like Fabfilter Pro-Q.
Very coarsening, you must equalize your sub to lowest level (which would be at 20 Hz) and then pile up so much power how your driver peak displacement would allow.
Either pick different driver, say this:
SB Acoustics :: 12" SB34SWPL76-4
Hi GM
I do not know what EBS means,
if I know that I'm not interested in the THX standart, which I understand is for movie effects. I only want low notes of music, bass, piano, etc. I have already given up 16 hz of a tube organ .....But it seems that I will end up giving up a subwofer and I will be happier, this is getting too complicated ....
The question is difficult ......
I have a place in the environment on the right, a corner is available there. Almost perfect for a triangular design cabinet, in the style of a Klipschhorn ....( Corner marked with blue, I regret the deprofitness ...)
I think that being the omni-directional bass frequencies, it would not affect that the cabinet is far from the rest (there are 4 in the other room) .....
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