I must choose a driver within what I have at my disposal: I have gone directly to the subwofers section.
Bajos
The 18 Sound 1400 is the one that seems more suitable, except for the 21 inches that I agree with you in it would be a misnomer for the use I am going to give you.
I do not want to use electronic correction, and I do not see it as important for what I'm looking for.
In the Dayton SPA250 board amplifier you will have the necessary, frequency cut-off (it will be 80 HZ), phase inverter and especially high level connection to the valve amplifier.
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Greets!
Extended B*** Shelf alignment, i.e. large cab tuned at, or below, Fs. At 150 L, it is too small for this driver to perform well.
A tapered TL [TQWT] is a simplification of a cab with a long, large vent, which this driver's specs works well in, even when undersized and if we ignore the cinema THX reference, then the one I designed will also cover 16 Hz organ notes and since you have a corner to place it, all the better and can be made triangular if desired.
Unfortunately, it appears to be way too far away from the mains, i.e. with an 80 Hz/4th order XO it ideally needs to be < ~54 cm [215 cm max] from the farthest speaker to blend well if there's no electronic time delay used.
GM
A tqwt with the driver chosen? :
Comment=18Sound 18LW1400 22 Hz TQWT
And the dimensions? and design ? Is not it better to go for any of the manufacturer's designs? What's wrong with them?
Correct.
According to you they are too big and tuned too high for your application [app]. All the design details are in the '.txt' file I uploaded, but you have to have Hornresp loaded to install/view it. I am not setup to draw it with dimensions, bracing, etc., details, just do sims.
GM
Enclosure Design for Eightenn Sound 18LW1400
Ok, it's clear. 18LW1400 are well-known performer with good bang for the price.
But, again, beware of the fakes and double check the quality of impregnation of the suspension system.
Most of my friends have to think so, but all of doubts was dispelled since they have listen to properly tuned systems.
Get rid of doubts, just try something like MiniDSP Dirac+UMIK.
UMIK-1 + Dirac RCS
I know the very high-detailed, but soft and evolving sounding of the DTQWT with tube amp. But you can be sure that coupling it with the sub without sophisticated correction will be uncommonly hard.
Based on the living conditions listening levels i would prefer to make a good correction instead of adding a sub without correction.
Just use yours preamp output paralleled or place 20 kOhm to 1 kOhm divider and you will have common line level from your high level.
Ok, it's clear. 18LW1400 are well-known performer with good bang for the price.
But, again, beware of the fakes and double check the quality of impregnation of the suspension system.
Most of my friends have to think so, but all of doubts was dispelled since they have listen to properly tuned systems.
Get rid of doubts, just try something like MiniDSP Dirac+UMIK.
UMIK-1 + Dirac RCS
I know the very high-detailed, but soft and evolving sounding of the DTQWT with tube amp. But you can be sure that coupling it with the sub without sophisticated correction will be uncommonly hard.
Based on the living conditions listening levels i would prefer to make a good correction instead of adding a sub without correction.
Just use yours preamp output paralleled or place 20 kOhm to 1 kOhm divider and you will have common line level from your high level.
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A link to EBS description: The Subwoofer DIY Page - Extended Bass Shelf systems
Comparison in liters (according to the external dimensions of the cabinet) and its frequency response.
270 litros big cabinet
212 litros small cabinet
View attachments
As you can see, it behaves much better in the first octaves the larger cabinet. As I stated at the beginning of the thread.
There are physical laws that can not be modified to taste, they are unalterable.
Wavelength acoustic sound wave air sound waves frequency calculation temperature wave no air pressure speed of sound - sengpielaudio Sengpiel Berlin
Here are the wavelengths next to 30 degrees Celsius of temperature.
30 hz are 17.46 meters.
20 hz are 11.64 meters.
So I think I'll go through the bigger cabinet.
Thanks to all, my English is very limited to get into controversies that lead to nothing....
270 litros big cabinet
212 litros small cabinet
View attachments
As you can see, it behaves much better in the first octaves the larger cabinet. As I stated at the beginning of the thread.
There are physical laws that can not be modified to taste, they are unalterable.
Wavelength acoustic sound wave air sound waves frequency calculation temperature wave no air pressure speed of sound - sengpielaudio Sengpiel Berlin
Here are the wavelengths next to 30 degrees Celsius of temperature.
30 hz are 17.46 meters.
20 hz are 11.64 meters.
So I think I'll go through the bigger cabinet.
Thanks to all, my English is very limited to get into controversies that lead to nothing....
Attachments
Yes, it have slightly better response.
But the driver will be undamped and bass sounding will be too boomy.
Driver need to have some brakes and the air inside a box will perform very like.
Of course! But wavelength are bad to use for estimating box size, there works Thielle-Small and Helmholtz laws.
And now you need to take in advance very different laws.
You are trying to join sounding from Eminence Deltalite having Bl/Mms = 0,32 with 18Sounds 18LW1400 having Bl/Mms = 0,12. There are huge dip between them.
First as fast like lightning especially placed at offset horn and last as powerful like truck. They can go together at one highway, but it's necessary to provide different conditions for each of them.
If you place 18LW1400 in oversized cab you will have fast attack and very long response, especially if you tune the box around Fs, sound will be bOOOOmEEEEd and echoed-eeed-eed-ed.
Doesn't see to response curve, let it be any.
See to group delay graph in my message, it have the most needed info.
Eventually ask Troels Gravesen.
Try a B4 allignment which will give you a Qts of about 0.7071. Not boomy and it will have extended bass response. With such a large driver, the cabinet will need a lot of bracing.
So run those T-S parameters through the formulae and build the box to the correct size. Don't forget to allow extra space to allow for the room taken up by the rear of the woofer and the bracing. If you do this right, you will have a sub box that will keep a smile on your face.
-Chris
So run those T-S parameters through the formulae and build the box to the correct size. Don't forget to allow extra space to allow for the room taken up by the rear of the woofer and the bracing. If you do this right, you will have a sub box that will keep a smile on your face.
-Chris
Of course your comments are welcome, thank you.
Do you have plans for those sealed boxes?
They also serve for 1400 like this design?
http://www.18sound.it/Portals/0/EnclosuresKits/18Sub_v1.pdf
I have not been able to find sealed box plans for 18LW1400...
Hi GM
Ops, I wanted to install Hornresp , but the decompressor is the archaic Win Zip. I do not want to keep loading programs on my computer.
You would not do me the favor of attaching a view of the project that you suggest ?
(Press print screen and then paste in a new window of program Paint , then save it as .jpg).
The time delay could be remedied by locating the cabinet in the corner that is to the left of the main speakers.
But, ideally, it would have to be a triangular design ...
I guess I'm asking too much, I know .....: Eek: , I'm sorry ...
Regards !
Hi Chris
Thanks, but without plans and dimensions I can not perform a B4 alignment, nor any other....
I hope to achieve that smile on my face anyway, this boat will reach a good port.
Regards !
Hi juuzo
Ops,
Here bespav attached a sealed, is something similar in liters to your cabinet? I see it very small, only 28 liters.Attachments
I don't have particular plans for these boxes but here is few pictures of my project.
These are made on 18mm plywood with front panel double thickness. Braces inside are made of 30x30mm bars. Stuffing inside is from Ikea pellows.
Attachments
Hi academia50,
Those specs for the box are too small to take advantage of the woofer's lower resonant frequency. You should try a ported box with a Qts of about 0.7071. I haven't got any box programs that run under the newer windows OS, but I'm pretty sure you can find something that does. I'm going to try with this free design software:
AJ Audio Subwoofer Box Enclosure Design Software - Sub Speaker Cabinet Building Program Downloads
-Chris
Edit: What this program cooked up for a 4th order Butterworth (ported box):
Vb (litres) - 101.5
Fb (Hz) - 41.1
F3 (Hz) - 49.4
Port Length (cm) - 30.7
Port dia (cm) - 12 (too small, but for concept it will be used)
Here you gain some low frequency response back.
One thing I really have to mention now is that the woofer you are using is imperfect for the task. I've built many 8" and 10" designs that had F3 down in the low 30 Hz and high 20 Hz regions, and what you have there looks like an instrument speaker. You lose way too much low frequency extension with those woofers. If building a ported box, look for a Qts of 0.383 or close to that.
I've also built some real animals using 15" and 18" drivers, and some had response (F3) near 20 Hz. That is getting destructive, but certainly fun too. I know you have your drivers already, but they don't seem to be designed for subwoofer use. One would think that for their size, they would support a much lower frequency.
Those specs for the box are too small to take advantage of the woofer's lower resonant frequency. You should try a ported box with a Qts of about 0.7071. I haven't got any box programs that run under the newer windows OS, but I'm pretty sure you can find something that does. I'm going to try with this free design software:
AJ Audio Subwoofer Box Enclosure Design Software - Sub Speaker Cabinet Building Program Downloads
-Chris
Edit: What this program cooked up for a 4th order Butterworth (ported box):
Vb (litres) - 101.5
Fb (Hz) - 41.1
F3 (Hz) - 49.4
Port Length (cm) - 30.7
Port dia (cm) - 12 (too small, but for concept it will be used)
Here you gain some low frequency response back.
One thing I really have to mention now is that the woofer you are using is imperfect for the task. I've built many 8" and 10" designs that had F3 down in the low 30 Hz and high 20 Hz regions, and what you have there looks like an instrument speaker. You lose way too much low frequency extension with those woofers. If building a ported box, look for a Qts of 0.383 or close to that.
I've also built some real animals using 15" and 18" drivers, and some had response (F3) near 20 Hz. That is getting destructive, but certainly fun too. I know you have your drivers already, but they don't seem to be designed for subwoofer use. One would think that for their size, they would support a much lower frequency.
I like them very much !
No matter that you do not have the plans.
Are 120 liters each or adding the pair of cabinets ?
Very thanks and regards
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