DIY Sealed Subwoofer

aeroash

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Skilful FMs,

I’m looking for a 15” Sealed Subwoofer. If anyone one of you can build me one or have any leads I’ll be grateful.

I would be happy to discuss this further via PM.

Thanks & Cheers
 

manek

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Skilful FMs,

I’m looking for a 15” Sealed Subwoofer. If anyone one of you can build me one or have any leads I’ll be grateful.

I would be happy to discuss this further via PM.

Thanks & Cheers
Now thats what I would call a good sub for music. 15” and sealed.
Found this link with a few 12” ones

For DIY, no clue.
 

DB1989

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Have you checked out this thread?


Something to think about! 😂
 

aeroash

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Have you checked out this thread?


Something to think about! 😂
Yea. I’ll have to shift my cot out and sleep outside.
 

jenson

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Sadik only makes enclosures no? I would also like guidance on the enclosure size and driver selection.
now banned (?), kanwar had some good builds... He seemed to have good tech know how... Not sure how to reach him though.. Perhaps manav can help..
 

Vineethkumar01

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Sadik only makes enclosures no? I would also like guidance on the enclosure size and driver selection.
Hi
If you are interested in learning designing the speaker by yourself,
please take a look at this post (yes it is my own thread on diyaudio):
and start using speakerboxlite app. Get a few drivers simulated.
Then we can all chime in with suggestions.. :)

PS: I personally would love to see some DIY effort going on in this forum. It is mostly due to lack of it or the interest that i have shut up and not posting anything here
 

rajan-

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aeroash

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Hi
If you are interested in learning designing the speaker by yourself,
please take a look at this post (yes it is my own thread on diyaudio):
and start using speakerboxlite app. Get a few drivers simulated.
Then we can all chime in with suggestions.. :)

PS: I personally would love to see some DIY effort going on in this forum. It is mostly due to lack of it or the interest that i have shut up and not posting anything here
My first preference would be for someone to build it for me.
If there are no takers for the project, then I can build an enclosure myself, with inputs from FMs for driver selection, and cabinet size.
I read your post and several others from the link you posted. It’s all Greek to me.

My requirement is a sealed box with a 15” driver, mostly for music, with the occasional “slam” for movies. I do not care for loudness. All that matters to me is tight, well-articulated bass. This will be placed in an 11’ x 11’ room.

I would highly appreciate any guidance on this project. Please understand that you’re talking to someone technically inept in this matter. I will not understand any of the technical jargon. I will try my very best to keep up. I can follow instructions well, so please let me know how to proceed.

Shooting in the dark, with zero knowledge of drivers, I came across this piece.

F0D1B3C7-E506-46B3-86F7-B2CEFA9124E3.jpeg

I also found the box suggestions as follows:
Sealed box of 3.0 cubic feet with stuffing has and F3 of 45Hz and F6 of 34Hz.

Am I on the right path?
 
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Vineethkumar01

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@aeroash: The reason why I suggested to read only the post I linked is because other posts can be distracting to your requirement of selecting a driver for your subwoofer.
Anyway the purpose was to get introduced to speakerboxlite app which can be used on a phone. The inputs to that app can be desired box volume (from the perspective of max. sized box that can be accomodated at home). Selecting brands of drivers that one is interested in/available in the country. Selecting bass alignment like bass reflex or sealed etc. These are specifying your requirement at the highest level not going into sealed alignment nitty gritties.

Selecting drivers first may not be a good idea. As you have described in previous post, thinking of application first is the way to go (eg: you want sealed alignment, no requirement for high SPLs etc). I don't know why you are interested only in 15inch drivers though.. Why not 12inch or even 18inch?

The driver you listed maybe a good driver but maynot be naturally suitable for a sealed alignment that gives reasonably good SPL levels. For this, we need to do a simulation to understand more.. Let me try using the app and see if it gives some useful recommendations.
 

aeroash

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@aeroash: The reason why I suggested to read only the post I linked is because other posts can be distracting to your requirement of selecting a driver for your subwoofer.
Anyway the purpose was to get introduced to speakerboxlite app which can be used on a phone. The inputs to that app can be desired box volume (from the perspective of max. sized box that can be accomodated at home). Selecting brands of drivers that one is interested in/available in the country. Selecting bass alignment like bass reflex or sealed etc. These are specifying your requirement at the highest level not going into sealed alignment nitty gritties.

Selecting drivers first may not be a good idea. As you have described in previous post, thinking of application first is the way to go (eg: you want sealed alignment, no requirement for high SPLs etc). I don't know why you are interested only in 15inch drivers though.. Why not 12inch or even 18inch?

The driver you listed maybe a good driver but maynot be naturally suitable for a sealed alignment that gives reasonably good SPL levels. For this, we need to do a simulation to understand more.. Let me try using the app and see if it gives some useful recommendations.
I did try the app. This was one of the drivers that showed up.

I have no space for an 18” driver in the room. I already have a 12” sealed sub. I thought I’ll dabble in something one size bigger just to see what it brings to the table when compared to my 12” sub.
 

Vineethkumar01

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I did try the app. This was one of the drivers that showed up.

I have no space for an 18” driver in the room. I already have a 12” sealed sub. I thought I’ll dabble in something one size bigger just to see what it brings to the table when compared to my 12” sub.
Ok.. This is good. I will do a more detailed simulation of this woofer in a sealed box once I get my personal laptop today and post here.. :)
 

Vineethkumar01

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So here are more detailed sims for a sealed box for this driver (although based on a simpler model than the klippel based results).

Box volume specs:

It says one needs to have a 105 litres volume available inside the box (with stuffing inside) for the driver to give the kind of output levels power handling etc shown in below plots
1662641905382_image.png
Driver in box responses
SB Acoustics SB42FHCL75-6 Six-pack.png
Out of all the above pictures 1st plot is the most important. In it the light blue line shows the maximum output SPLs tbat can be got out of this configuration (driver in this particular box). The black curve shows the output that can be achieved in practice if you give the driver about 180 watts of power. At this level, we are still not excusion limited or power handling limited so a bit more power can be applied to the woofer and a bit more SPL can be eeked out..

what the black curve essentially says is when you apply this much power into the woofer, you will be able to get about 98dB of SPL at 20Hz, avout 104dB of output at 30Hz and about 110dB of output at 50Hz.

I know how this bass sounds as I have 4 x Satori WO24P-8 9inch woofers in a very similar alignment at home as shown below :D




IMG_20220908_184221.jpg
This bass is sort of quick. It is there one moment and then it vanishes. If the room permits, it doesn't linger around much. I really like it especially with music (i dont see many movies anyway).. Everyone may not.. :D If one is looking for hard hitting "chest thumping" window shaking bass, this is not the driver or the bass alignment to look for.. :) Now the question is who is going to make this box for making this subwoofer
 

Vineethkumar01

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black curve essentially says is when you apply this much power into the woofer, you will be able to get about 98dB of SPL at 20Hz, avout 104dB of output at 30Hz and about 110dB of output at 50Hz.
Just as a side note, This is all asumming 2 pi radiation. In a practical scenario, with 4pi radiation one may subtract 6dB from above numbers in aworst case scenario
 

aeroash

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Box volume specs:

It says one needs to have a 105 litres volume available inside the box (with stuffing inside) for the driver to give the kind of output levels power handling etc shown in below plots
Thanks @Vineethkumar01
That’s 3.7 cubic feet. That’s doable.
The box size works out to be 18” x 18” x 27”.
Does the shape of the box matter?

I know how this bass sounds as I have 4 x Satori WO24P-8 9inch woofers in a very similar alignment at home as shown below :D




View attachment 71774
This bass is sort of quick. It is there one moment and then it vanishes. If the room permits, it doesn't linger around much. I really like it especially with music (i dont see many movies anyway).. Everyone may not.. :D If one is looking for hard hitting "chest thumping" window shaking bass, this is not the driver or the bass alignment to look for.. :) Now the question is who is going to make this box for making this subwoofer
This is perfect! Lovely speakers 😃
 
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Vineethkumar01

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Thanks @Vineethkumar01
That’s 3.7 cubic feet. That’s doable.
The box size works out to be 18” x 18” x 27”.
Does the shape of the box matter?


This is perfect! Lovely speakers 😃
So I made an enclosure calculation based on dimensions shown in below pic to get the volume of 105 Litres. I have roughly allocated some 2 litres for volume taken up by driver and 8 litres for volume taken up by bracing. Depending upon the bracing scheme, these numbers vary a little


I have assumed a double baffle of 36cm thickness and put only 18cm thick walls everywhere else. These numbers cam be read out from below pic.

A key aspect of woofer/subwoofer cabinet is to brace it well.. Now we want some one to draw a box with these kind of dimensions and decide the bracing scheme etc.. :)

The below pic also shows the location frequencies of box modes. In simple words, we domt have to see (hear) those peaks that we see in the below pic. Thier locations in frequency are decided by the enclosure dimensions. For this subwoofer box, they are not much of a problem since you will be crossing it over to other speakers well below 200Hz.

Also, it is to time to start thinking about power amplifier for this, crossover/low pass filter etc.. You need a minidsp and a separate amplifier or a plate amplifier with filter cut off frequency adjustment etc for all this.

Keeping all these in mind, coming up with an estimate of cost is also important.. :D

1662733806537_image.png
 
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rwnano

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My first preference would be for someone to build it for me.
If there are no takers for the project, then I can build an enclosure myself, with inputs from FMs for driver selection, and cabinet size.
I read your post and several others from the link you posted. It’s all Greek to me.

My requirement is a sealed box with a 15” driver, mostly for music, with the occasional “slam” for movies. I do not care for loudness. All that matters to me is tight, well-articulated bass. This will be placed in an 11’ x 11’ room.

I would highly appreciate any guidance on this project. Please understand that you’re talking to someone technically inept in this matter. I will not understand any of the technical jargon. I will try my very best to keep up. I can follow instructions well, so please let me know how to proceed.

Shooting in the dark, with zero knowledge of drivers, I came across this piece.

View attachment 71771

I also found the box suggestions as follows:
Sealed box of 3.0 cubic feet with stuffing has and F3 of 45Hz and F6 of 34Hz.

Am I on the right path?
Hi aero... there's this known guy called Mr Sethi who's running firm called 4d furnishers in Delhi. He would be great to connect with and can build a value for money solution for you. DM me for his contact info
 
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