Dual 12" OB H-Frame Construction

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Captainhemo

Dual 12" OB H-Frame Construction
« on: 22 Jul 2014, 05:26 am »
Not sure how interesting this will be but figured I'd post it  anyhow....

I'm starting with  one dual 12" OB H-Frame, can't afford to  do them both right now .  This will replace my current sub, a CSS Quartet 10 ( 10"  SDX 10 driver and  2 10" PR;'s).  Eventually I'll  build the 2nd H-Frame and have them config'd in stereo.

So,   I started with 4  panels,  27" x 15" x 3/4"



I laminated these into 2 panels


Next the panels were trimmed to size  ( 26 3/4" x 13 3/4"  and  3/4" x 1/2" dados were cut for the  baffle and braces


I  cut the baffle 26 3/4" x 14" (an extra inch wider for the dados), routed the 11" holes for the woofers and  put a  small roundover on the rear  side of each cutout. Braces were cut 14" x 6 1/2".   Also  laminated  a base and a top plate that I left  long so I could  trim it off after I glued it in place



Next I dry fit it all together to make sure there were no issues


After that it was time for some  glue


I had to use screws  instead of clamps to  glue the top plate  on,  I don't have long enough clamps  :(
Plan was to   let the glue set up and then   get the flush trim  bit out and zip off the excess....  problem.....  my  flush trim bit only has a 1"  cutting blade :duh:  Had a 2"   one sent out this afternoon.  So instead,  I   did some sanding  and  put a 3/8" round over on all the  inner edges  of the cabinet.  I'll add 3/4" roundovers to all lthe outer edges once I get the new  flush trim bit and can   cut off the excess  from the top plate.  Note, I'm  just dong the round overs on the cabinet for appearence.


-jay

Guy 13

Re: Dual 12" OB H-Frame Construction
« Reply #1 on: 22 Jul 2014, 05:33 am »
Hi Jay.
Nice project.
Nice step by step slideshow.
Anxiously awaiting the next pictures of your project.

Guy 13

Hopefully in the following threads
you will mention the following:
What finish the wood?
Spikes or rubber feet?
What make + model of plate amplifier.
What make + model of drivers?
Will the drivers be firing in opposite directions.
Will it have fron and/or back grills.
So many questions, now I can't wait for answers.


mresseguie

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Re: Dual 12" OB H-Frame Construction
« Reply #2 on: 22 Jul 2014, 06:25 am »
I agree with Guy, Jay. [Must be cuz we both have Asian wives. :lol:] That's a nice looking project you've got going.

I'm still fairly new to OB speakers, so could you educate me a bit? Where will the amplifier be placed?

Big question: What are the advantages of an OB subwoofer over a sealed subwoofer (assuming the same drivers and amps are used)?

Michael

If I should ask these questions in another thread, by all means someone redirect me. :oops:

Captainhemo

Re: Dual 12" OB H-Frame Construction
« Reply #3 on: 22 Jul 2014, 07:18 am »
 :lol:  you guys are funny.  I saw  Guy's post over in another circle  regarding  your wive's  the other day too.

No worries about asking here Micheal,,  heopefully a few others will chime in to

As I understand it,  with the OB subs, you'lll get much more detailed, accureate "clean" bass.  A lot less boom which is something I am really hoping for. With the servo controlled drivers,   you aren't supposed tolose the  "impact" either ,  just some SPL   compared to the sealed   versions.  I'm sure someone else will  provide you with more details but that's a start
  Supposed to be amazing for audio  which I have   really migrated towards since building my OB7's. I just  very rarilly  watch movies any mre  ,  pretty much all  2 (2.1) ch audio so the OB subs seemed the logical choice
Don't get me wrong ,   it is not that the OB7's don't sound good   for HT use,  I  just have lost all interest  in it. I do still wastch the occasional movie with my neice but other tan that,  nada.

Sure am looking forward to   hearing what  the OB subs  will do

-jay

Guy 13

Re: Dual 12" OB H-Frame Construction
« Reply #4 on: 22 Jul 2014, 07:18 am »
I agree with Guy, Jay. [Must be cuz we both have Asian wives. :lol:] That's a nice looking project you've got going.

I'm still fairly new to OB speakers, so could you educate me a bit? Where will the amplifier be placed?

Big question: What are the advantages of an OB subwoofer over a sealed subwoofer (assuming the same drivers and amps are used)?

Michael

If I should ask these questions in another thread, by all means someone redirect me. :oops:

Hi Jay and Michael.
Yes, that's must be it, we both have Asian women. :lol:
I am sure some AC members will/can tell you what are the advantages
of Open Baffle versus Sealed or vented.
If I've choose Open Baffle it's not because the sealed (Servo or not)
is inferior in sound.
It's because they are different and I like something different,
plus to me, the OB sound better, at least with what I have now.
However, OB need more room, therefore later,
when I am confine into a smaller apartment,
I might (If I have no choice) go with (Several) small sealed subwoofer.
I don't want to answer for Jay, but I think the plate amplifier will be
in a separate box.
Now, I am out, I will let Jay do the writing and posting
with hopefully, lots of nice pictures.

Guy 13


 

monte

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Re: Dual 12" OB H-Frame Construction
« Reply #5 on: 22 Jul 2014, 11:26 am »
What made you do a h- frame over a w- frame? Thanks for the picts it's looking good.Keep us posted.Paul

Early B.

Re: Dual 12" OB H-Frame Construction
« Reply #6 on: 22 Jul 2014, 12:02 pm »
Where will the amplifier be placed?

The amps for OB subs are typically in a separate box (or no box at all). One of the problems with most sealed subs is that the amp is attached directly to the box, making it subject to lots of vibration. Not a good thing.

Guy 13

Re: Dual 12" OB H-Frame Construction
« Reply #7 on: 22 Jul 2014, 12:16 pm »
The amps for OB subs are typically in a separate box (or no box at all). One of the problems with most sealed subs is that the amp is attached directly to the box, making it subject to lots of vibration. Not a good thing.

Hi Early B.
I thought that solid state amplifier were not subject to vibration.
(Tubes amplifier, yes...)
Does that means it would be better if my subwoofer ss amplifier were in a seperate box away from all the powerful boom boom of my subwoofer?
It's the first time I hear something like that.
Of course even after 66 years,
I have not heard everything about everything.

Guy 13



Early B.

Re: Dual 12" OB H-Frame Construction
« Reply #8 on: 22 Jul 2014, 12:40 pm »
Hi Early B.
I thought that solid state amplifier were not subject to vibration.

There is an huge audiophile accessory business based on vibration reduction. Many of us who have experimented with vibration isolation devices have noticed sonic improvements, even with solid state amps. With tube amps, it's obvious to want to control vibration, but the same is true for SS amps. Imagine a SS amp's internal parts vibrating incessantly. What impact would that have on the sound (recall that sound is vibration that we hear)? This vibration issue is magnified exponentially with an amp attached to a subwoofer cabinet.

Guy 13

Re: Dual 12" OB H-Frame Construction
« Reply #9 on: 22 Jul 2014, 01:15 pm »
There is an huge audiophile accessory business based on vibration reduction. Many of us who have experimented with vibration isolation devices have noticed sonic improvements, even with solid state amps. With tube amps, it's obvious to want to control vibration, but the same is true for SS amps. Imagine a SS amp's internal parts vibrating incessantly. What impact would that have on the sound (recall that sound is vibration that we hear)? This vibration issue is magnified exponentially with an amp attached to a subwoofer cabinet.

Hi Early B.
If it's not good or even so bad,
why 99% of the speaker manufacturers attached their ss amp to the enclosures?
I wonder if I detach my ss plate amplifier from my H type subwoofer enclosure
by how much the sound will improve ???

Guy 13


Guy 13

Re: Dual 12" OB H-Frame Construction
« Reply #10 on: 22 Jul 2014, 01:18 pm »
Hi Jay.
Sorry to hijack your thread like that,
but while we wait for your next set of pictures,
we have nothing else better to do than... Well, what we are doing now.
If you want, you can hate me...

Guy 13

Early B.

Re: Dual 12" OB H-Frame Construction
« Reply #11 on: 22 Jul 2014, 01:41 pm »
why 99% of the speaker manufacturers attached their ss amp to the enclosures?

That's easy -- the target market for subwoofers is comprised of 99% non-audiophiles. Only people like us would consider separating the plate amp from the cabinet. There are other reasons to do so, but we have derailed this thread long enough.

corndog71

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Re: Dual 12" OB H-Frame Construction
« Reply #12 on: 22 Jul 2014, 02:07 pm »
Looks great so far!  :thumb:

Ever since Danny introduced the V-1 I have been wanting a pair of these OB subs.  It's amazing to me how even a fairly simple cabinet design can still be so much work.  Sadly, I am not cut out to be a wood worker. 

I would be real interested in the weight of the finished cabinet with and without subs.

Captainhemo

Re: Dual 12" OB H-Frame Construction
« Reply #13 on: 22 Jul 2014, 04:34 pm »
What made you do a h- frame over a w- frame? Thanks for the picts it's looking good.Keep us posted.Paul

Figured I'd make them "match" my OB7's, an H Frame seemed  a better fit .  Usually when I see Danny  use them paired with a speaker,  they are in stand alone H Frames or built into the speakers cabnets in an H Frame.

Ever since Danny introduced the V-1 I have been wanting a pair of these OB subs.  It's amazing to me how even a fairly simple cabinet design can still be so much work.  Sadly, I am not cut out to be a wood worker. 

I would be real interested in the weight of the finished cabinet with and without subs.

I think jparkhur is working on a  simple flat pack for the H  frames,  might want to contact him and see where they  stand.
Even without  the base attached yet,  it is heavy.  With the  panels doubled up ,  the weight piles on fast.   Approx 3/4 sheet of MDF  in  this cabinet.  According to the UPS   shipment details,   the packae weights  62 lbs so  add  a good chunk of that too .

Hi Jay.
Sorry to hijack your thread like that,

Guy 13

No worries, post away   :lol:

As for the amp,  I  just built an open box  to houe it in.  I am going to put some small rubber feet on it and try it both ways... sitting ontop of the enclosure as well as on the ground to see if I notice any difference. I kind of doubt  it, but you never know

-jay

gregfisk

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Re: Dual 12" OB H-Frame Construction
« Reply #14 on: 23 Jul 2014, 03:14 am »
Jay, Really nice look on these. Can't wait to here what they do for your system, I'm curious if they smooth out your room a bit and how much better the bass is.

Keep the pictures coming, I really enjoy them :thumb:

Captainhemo

Re: Dual 12" OB H-Frame Construction
« Reply #15 on: 23 Jul 2014, 03:40 am »
Jay, Really nice look on these. Can't wait to here what they do for your system, I'm curious if they smooth out your room a bit and how much better the bass is.

Keep the pictures coming, I really enjoy them :thumb:

Hey Greg,  any word on your   project   ?    Been anxiously awaiting to see how they are going to   look  :)

-jay

monte

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Re: Dual 12" OB H-Frame Construction
« Reply #16 on: 23 Jul 2014, 06:34 am »
This is what I want to replace my sunfire jr with.

bdp24

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Re: Dual 12" OB H-Frame Construction
« Reply #17 on: 24 Jul 2014, 11:12 pm »
Really excellent H-Frames, Cap. They look to have been inspired by the black pair Peter J made and posted pics of here awhile back (the top and bottom of the frame extending past the vertical side panels). I'm using W-Frames at the moment, but when I get around to making H's, I'm making mine in a similar design (but without the extended top and bottom), also doubling up on the MDF for the panels, and the baffle as well, just to make sure. Doubling the horizontal brace seems unnecessary, I think. What do you say Danny?

Danny Richie

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Re: Dual 12" OB H-Frame Construction
« Reply #18 on: 24 Jul 2014, 11:21 pm »
No need to double up the horizontal brace.

Captainhemo

Re: Dual 12" OB H-Frame Construction
« Reply #19 on: 24 Jul 2014, 11:57 pm »
Really excellent H-Frames, Cap. They look to have been inspired by the black pair Peter J made and posted pics of here awhile back (the top and bottom of the frame extending past the vertical side panels). I'm using W-Frames at the moment, but when I get around to making H's, I'm making mine in a similar design (but without the extended top and bottom), also doubling up on the MDF for the panels, and the baffle as well, just to make sure. Doubling the horizontal brace seems unnecessary, I think. What do you say Danny?

Once  the  new flush trim bit arives (need a longer one), that top panel will be trimmed down to the overall width .I did see the pics  you mention, I think they were actually made by Ruben  (post #59 http://www.audiocircle.com/index.php?topic=125667.40 ) and  really liked them, thought about going the same way but I want these towers to have a similar shape to the OB7's (at least from the front) so there will only be the wider base.   I did not double up the baffle or the braces.... thought about  doing the baffle  but figured with the dados and the little area of baffle left exposed,  there would be little room for any   movement /resonance once the drivers are installed.  It's  very solid as it it is

Not much I can do  until that bit arrives .... this afternoon I did  finsih up the open box for the amp Gone back to the Duplicolor paint for the finish but going a little draker than the  OB7's ,  figured the darker color  would   be more versitile if I ever decide to change spekaers in the future . Color is  called  Metallic Graphite.




-jay .
« Last Edit: 25 Jul 2014, 01:45 am by Captainhemo »