The V.B.S.S. DIY subwoofer design thread - Page 27 - AVS Forum | Home Theater Discussions And Reviews
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post #781 of 1501 Old 04-19-2018, 12:43 PM
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Quote:
Originally Posted by mons0160 View Post

If this is too much for this thread, i can start mine own as well.
Yep :-)

Just repost the info from these last few posts in a new thread, try to include as much specific info about your room size, budget, box size and any other limitations.

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post #782 of 1501 Old 04-20-2018, 12:19 PM
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Quote:
Originally Posted by Brazle View Post
Yep :-)

Just repost the info from these last few posts in a new thread, try to include as much specific info about your room size, budget, box size and any other limitations.
You got it! Thanks again

https://www.avsforum.com/forum/155-di...-now-what.html
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post #783 of 1501 Old 04-27-2018, 06:52 AM
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Since these are currently on sale, I'm thinking about getting 4 of these but had a few questions.
Current setup:
LR: Fusion12
C: Fusion 8 horizontal
Surrounds: Volt10
Subs: 4 HT18 4cf sealed

Goal: more bass Specifically in the upper range for gunshots, chest slam, etc where I think these will do well. Baby steps in upgrading so eventually i may change to ported HT18's or replace them altogether.

I was thinking of adding these to get increased mid bass in the upper end where the HT18's don't have the sensitivity and the Fusion12's are a little lacking. What I am trying to decide is how to integrate them. I have been considering several options:
1. use the 15Hz tune and get more bass all around. Can you ever have too much bass?

2. use the 31Hz tune and cross them over to the HT18's. I would get an 6000dsp for my HT18's and roll them off around 50-60 and then use a crown xls1500 HPF to bring in the PA460s letting the receiver cut them off around 120. I have also been checking out VicTorious1's design here so that is an option as well.

3. Use one set of these as nearfields with potentially a different crossover. My original thought was to use the HT18's as nearfield as i was concerned with localization being an issue in the higher frequency range of the pa460 however I have been reading several other threads where people are using the 460's nearfield and love it.

Really not sure what the best option is right now since depending on how I decide to integrate them, the amp requirements may change since I don't have any DSPs right now. Any advice would be welcome as I have been through this thread and several other's multiple times and am still undecided. Sometimes DIY presents too many options for indecisive people like myself

EDIT
I guess there is also a fourth option to just use the VBSS at 15 Hz and just replace all my HT18's . . . . I'm sure would have no problem selling them.

Last edited by Jedi940; 04-27-2018 at 08:42 AM.
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post #784 of 1501 Old 04-27-2018, 10:13 AM
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I just ordered a PA460 to use as a sub in my truck.
Special THANKS to John, @LTD02 for all his time and help with the design !!
Can’t wait. Quick question. How much weight savings would there be by using .75” plywood instead of .75” MDF ?
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post #785 of 1501 Old 04-27-2018, 12:05 PM
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Quote:
Originally Posted by tk123 View Post
I just ordered a PA460 to use as a sub in my truck.
Special THANKS to John, @LTD02 for all his time and help with the design !!
Can’t wait. Quick question. How much weight savings would there be by using .75” plywood instead of .75” MDF ?

According to this chart http://www.hooddistribution.com/product-weights/ plywood is around 2.47 lb./ft², while MDF is around 3.20 lb./ft²

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post #786 of 1501 Old 04-27-2018, 02:59 PM
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I feel like I remember reading somewhere in this thread about a 40hz-tune variation to the design for a music-only application? I've gone back and scanned through the pages but can't find it .... Am I imaging it?

What if you're building a dual VBSS setup STRICTLY for music... would it be better to tune it higher?
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post #787 of 1501 Old 04-27-2018, 03:46 PM
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I did this, a dual driver VBBS mod by @LTD02 , for MBM duty . . 2 drivers, 4 ohm load, 1 channel of a inuke6K

a very easy build

i believe it's HPF'ed at 40

the system is LFP'ed @120 and the VBBS sub has it's own channel thru a minidsp 2x4HD so there's lots of EQ horsepower there . .

so I can very much enjoy "just " mainstream legacy stereo with the F15's and this sub alone

but it's nice to have options . .
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post #788 of 1501 Old 04-27-2018, 08:21 PM
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Nice custom dual cabinet. I am planning to do separate VBSS cabinets in the corners of my audio room.
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post #789 of 1501 Old 05-01-2018, 02:05 AM
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VBSS Slot Port Version

I received a question about a slot ported version. I can't recall if one has already been drawn up or not. The OP mentions port dimensions, which seem about right.
The recessed driver option is gone because the panel wouldn't sit flush with the slot port. I resized several of the panels as well, so while this looks the same and will perform pretty much the same, it is a little different than the VBSS.

20Hz version
The 20Hz version has a port that goes across the bottom of the cabinet and then a little up the back of the cabinet. Tuning would be around 20hz with both ports open and about 15hz one port stuffed.

Baffle 27.75" x 22.00"
Rear 30.00" x 22.00"
Sides (2) 31.50" x 20.00"
Top 20.00" x 22.00"
Bottom 20.00" x 22.00"
Port boards:
horizontal 17.75" x 22.00"
vertical 8.00" x 22.00"
Port braces:
horizontal 19.25" x 1.50"
vertical 8.75" x 1.50"

Internal bracing required


31Hz Version
For the 31Hz mode version, everything is the same except the bottom port board is 10.50" long. There is no vertical port board in the 31hz version. Stuffing one port in the 31Hz version tunes the cab to about 22Hz.























rear view to see how the panels fit together








sometimes, things just work out. it just barely fits on one sheet of 48x96 ply (mdf tends to give an extra inch to allow for banged up corners in transport, so at 49x97 there is plenty of room on that too).










Recessed driver option
A recessed driver could be an option by creating a second baffle from 1/2" thick wood. The primary baffle is moved into the cab 1/2" in order to provide room for the 1/2" thick second baffle to sit flush with the front edges of the sides/top/top port panel. The only thing that would need to be modified is the bracing. Internal volume will be reduced by about 0.2 c.f. which is still 'close enough'.


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Last edited by LTD02; 05-01-2018 at 11:17 AM.
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post #790 of 1501 Old 05-01-2018, 02:08 AM
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@mtg90
could you double check the above post and if it checks out provide a link from within the o.p.? a few folks have asked me about this, so I figured it would be easier to answer it once really well rather than provide a half-azz answer over and over again.
thanks.
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post #791 of 1501 Old 05-01-2018, 06:06 AM
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Good idea John😎😉
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post #792 of 1501 Old 05-01-2018, 06:19 AM
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John designed one of these for me that looks pretty similar to the one above but it uses the Dayton PA 380 - 15" instead and I absolutely love it..got it beside the couch and it provides so much impact...
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post #793 of 1501 Old 05-01-2018, 06:58 AM
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Does anybody see a problem with using this driver PA460 or the PA380 in a very shallow box, approx. 12" deep, for nearfields behind my couch? I am pretty much limited to 12" for WAF since my couch is backed up to the wall. Looking to create a NF-VBSS
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post #794 of 1501 Old 05-01-2018, 07:03 AM - Thread Starter
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Quote:
Originally Posted by LTD02 View Post
@mtg90
could you double check the above post and if it checks out provide a link from within the o.p.? a few folks have asked me about this, so I figured it would be easier to answer it once really well rather than provide a half-azz answer over and over again.
thanks.
Yeah it looks good.

For most wondering as long as the internal volume and port tuning end up roughly the same it will work just fine with the VBSS amp settings even if the cabinet shape is quite different then the original.
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post #795 of 1501 Old 05-01-2018, 10:17 AM
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John designed a cab for me to go in my truck. My PA460 came in yesterday. Now it’s time to make sawdust !!
Obviously, my box will be smaller than the regular VBSS, but I think it will do what I want. 👍
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post #796 of 1501 Old 05-01-2018, 11:02 AM
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Originally Posted by mtg90 View Post
Yeah it looks good.
Super.

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post #797 of 1501 Old 05-01-2018, 08:24 PM
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I currently have 2 Dayton dvc385-88s tuned to around 21h. Would it be worth it to sell them and get 2 PA460s?

That would be going from 2 ported 15s to 2 ported 18s
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post #798 of 1501 Old 05-02-2018, 03:29 AM
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Originally Posted by z.pelton1996 View Post
I currently have 2 Dayton dvc385-88s tuned to around 21h. Would it be worth it to sell them and get 2 PA460s?

That would be going from 2 ported 15s to 2 ported 18s

it depends.


the dvc's have more volume displaced (excursion * area) so will have a little more low end capability. roughly a 3:2 ratio in this case.


the 460's are much more efficient, so will provide more output above 40hz or so.

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post #799 of 1501 Old 05-02-2018, 04:01 AM
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If you were running a dual VBSS setup for music only, would it be effective to tune the cabinet to something higher, like 40hz?

If so, would you decrease the length of the slot port?
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post #800 of 1501 Old 05-02-2018, 05:41 AM
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Quote:
Originally Posted by Craig S King View Post
If you were running a dual VBSS setup for music only, would it be effective to tune the cabinet to something higher, like 40hz?

If so, would you decrease the length of the slot port?

excursion and power are balanced well in the 31Hz tuning, which is one reason that I suspect @mtg90 chose that point. frequency response is a pretty nice rolloff too.


a higher tuning will provide a couple db more sensitivity in the bass 50-70 ballpark, but starts to get kind of peaky. that is how the cabs would be designed for p.a. use where absolute max output is desired.


the slot port vbss post has been updated with to reflect the 31hz option. that's what I'd recommend for most folks for music purposes.


this is roughly the difference in response between the 31hz and a 40hz tuning.


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post #801 of 1501 Old 05-02-2018, 11:12 AM
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Quote:
Originally Posted by LTD02 View Post
Quote:
Originally Posted by z.pelton1996 View Post
I currently have 2 Dayton dvc385-88s tuned to around 21h. Would it be worth it to sell them and get 2 PA460s?

That would be going from 2 ported 15s to 2 ported 18s

it depends.


the dvc's have more volume displaced (excursion * area) so will have a little more low end capability. roughly a 3:2 ratio in this case.


the 460's are much more efficient, so will provide more output above 40hz or so.
They would be used for 35hz and up. So how much more output would I get with the 460s?

Last edited by z.pelton1996; 05-02-2018 at 11:28 AM.
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post #802 of 1501 Old 05-02-2018, 12:31 PM
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Quote:
Originally Posted by z.pelton1996 View Post
They would be used for 35hz and up. So how much more output would I get with the 460s?

a lot. that's pretty much what the drivers are designed for.


in the 31hz tune cab, you would gain about 3-4db in the mid 30's climbing to about 7-8db by 60hz and even a little more higher up. the higher efficiency in the upper bass will provide a little more subjective 'kick' too.
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post #803 of 1501 Old 05-02-2018, 05:47 PM
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Quote:
Originally Posted by chadsmith013 View Post
John designed one of these for me that looks pretty similar to the one above but it uses the Dayton PA 380 - 15" instead and I absolutely love it..got it beside the couch and it provides so much impact...
Does that shrink the dimensions down, or is it about the same size?

Sent from my Moto Z (2) using Tapatalk
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post #804 of 1501 Old 05-02-2018, 06:13 PM
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^ some details, please . .

I don't have room for any more 18's . . .

but!
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L/R: Fusion 15 V2 , C: 88 Special , SL/SR: 88 Special(V2) , RL/RR: F-3, TF/TR: Volt 6's TM: SLX, FH: F4Q4
SUBMAXIMUS V2, ,Submaximus V3,LOWARHORNCustom Dual Driver VBSS,2 x 6000DSP
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post #805 of 1501 Old 05-03-2018, 05:50 AM
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Quote:
Originally Posted by Ortizer View Post
Does that shrink the dimensions down, or is it about the same size?

Sent from my Moto Z (2) using Tapatalk
they were similar..

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Nearfield: 2 Dayton HO 15's w/Inuke 6000DSP
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post #806 of 1501 Old 05-03-2018, 03:33 PM
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Quote:
Originally Posted by LTD02 View Post
excursion and power are balanced well in the 31Hz tuning, which is one reason that I suspect @mtg90 chose that point. frequency response is a pretty nice rolloff too.

a higher tuning will provide a couple db more sensitivity in the bass 50-70 ballpark, but starts to get kind of peaky. that is how the cabs would be designed for p.a. use where absolute max output is desired.

the slot port vbss post has been updated with to reflect the 31hz option. that's what I'd recommend for most folks for music purposes.

this is roughly the difference in response between the 31hz and a 40hz tuning.


Thanks for the info.



Any graphs showing the difference between a single UM18 in a Mini-marty versus a dual VBSS setup, but tuned to 31hz ?
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post #807 of 1501 Old 05-03-2018, 07:42 PM
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I wouldn't tune a UM18 to 31hz unless it was going in a car. The pair of PA460s will kill a single UM18 above 30hz.



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post #808 of 1501 Old 05-05-2018, 04:45 PM
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Thanks Samps, I didn't mean the UM18 tuned to 31hz, but thank you for the graph. Good to see another Pittsburgh guy too!

Let me rephrase,

I currently have a single UM18 in a mini-marty that is tuned to 17hz. I'm not getting the bass response from music I was hoping for with it. So I'm heavily considering a pair of PA460s in VBSS's tuned to 31hz. But before I invest more money into my second phase of subwoofers, I want to make sure the PA460s will do what I want them to for a 100% music application.
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post #809 of 1501 Old 05-05-2018, 05:10 PM
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Quote:
Originally Posted by LTD02 View Post
I received a question about a slot ported version. I can't recall if one has already been drawn up or not. The OP mentions port dimensions, which seem about right.
The recessed driver option is gone because the panel wouldn't sit flush with the slot port. I resized several of the panels as well, so while this looks the same and will perform pretty much the same, it is a little different than the VBSS.

20Hz version
The 20Hz version has a port that goes across the bottom of the cabinet and then a little up the back of the cabinet. Tuning would be around 20hz with both ports open and about 15hz one port stuffed.

Baffle 27.75" x 22.00"
Rear 30.00" x 22.00"
Sides (2) 31.50" x 20.00"
Top 20.00" x 22.00"
Bottom 20.00" x 22.00"
Port boards:
horizontal 17.75" x 22.00"
vertical 8.00" x 22.00"
Port braces:
horizontal 19.25" x 1.50"
vertical 8.75" x 1.50"

Internal bracing required


31Hz Version
For the 31Hz mode version, everything is the same except the bottom port board is 10.50" long. There is no vertical port board in the 31hz version. Stuffing one port in the 31Hz version tunes the cab to about 22Hz.























rear view to see how the panels fit together








sometimes, things just work out. it just barely fits on one sheet of 48x96 ply (mdf tends to give an extra inch to allow for banged up corners in transport, so at 49x97 there is plenty of room on that too).










Recessed driver option
A recessed driver could be an option by creating a second baffle from 1/2" thick wood. The primary baffle is moved into the cab 1/2" in order to provide room for the 1/2" thick second baffle to sit flush with the front edges of the sides/top/top port panel. The only thing that would need to be modified is the bracing. Internal volume will be reduced by about 0.2 c.f. which is still 'close enough'.


Thanks a lot. Like the design. Is there anyway you could include bracing like you did in the first post? I've tried to do bracing on my own, and I must be literally braindead since I failed miserably at it.

Is there anyway we can link this to the first post somehow so people can see all options?

Didn't realize the first post design included bracing, I just need some help cutting those ports/driver mount and this is not too hard.
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post #810 of 1501 Old 05-05-2018, 05:24 PM
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Originally Posted by Craig S King View Post
Thanks Samps, I didn't mean the UM18 tuned to 31hz, but thank you for the graph. Good to see another Pittsburgh guy too!

Let me rephrase,

I currently have a single UM18 in a mini-marty that is tuned to 17hz. I'm not getting the bass response from music I was hoping for with it. So I'm heavily considering a pair of PA460s in VBSS's tuned to 31hz. But before I invest more money into my second phase of subwoofers, I want to make sure the PA460s will do what I want them to for a 100% music application.
With a 31hz tune, the 460s will be hard to beat for the money with music. There are certainly better 18s available, but not for $90. So if your funds are tight, you can't go wrong. Stepping up to the B&C RBX18s would be an upgrade in either max spl or smaller cab, but they are of course more expensive. 31hz is near perfect for the 460s, but they will create more air velocity with that tune. I'm not sure if Matt ever did any chuffing tests at 31hz.
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