Captainhemo's OB-7 Build

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Captainhemo

Captainhemo's OB-7 Build
« on: 18 Feb 2013, 07:26 am »
Hi Guys
Well  I finally got my OB-7 build underway.  I ordered the kit from  Danny last week including the M130X upgrade as well as platinum bypass caps.  I also  got a couple sheets of no res this time ,  previously  I had been  using the  vinyl floor/open cell foam method of dampening the cabinets but figured I'd try the no res  this  go around.
Again,  as with my N3's,  Ron is  building the cross overs for me (thank you  Ron) and they will be externally  mounted on the rear baffle.  I'll build a removeable cover for them to provide easy access

With the recent  spell of warm weather , I  was able to get out in the garage and get started on the lower bass cabinets this past week.  I've been  talking about  this build for a couple months now so it was nice to finally  get going on it .
 
First step was to cut out all the parts for the 2 cabinets:


Lots of holes in the braces to cut out and then round over the top and bottom of each one



I started gluing in the braces into one side panle using a "false " rear baffle for alignment.  This was slow going as  I do not  own many clamps.   One at a time, making sure each  was 90  degrees to the side panel  and then letting the glue set up for a couple hours between  braces.  I made a cou-le 2.5" spacers to  help  with positioning the braces




Here is everything glued in and ready for the  2nd  side panel to be glued on


I made the tp plate only 6.5" wide to allow the  side panels to   overlap  it  and allow    the   tops to be trimmed with  a flush trim bit.  Also had to    make the side panels 3/4" taller as normally  the  top plate wouild set on top  of them.

After trimming, :


Here are a couple more shots of the internal bracing   from the front and rear




I got the 2nd cabinet all glued up and trimmed this weekend.  Twins :)


I had to pick up  another  small piece of MDF  to make the rear baffles ( I originally  had enough but somehow I screwed up the  cut   when ripping  the frist one to width).  Anyway,  they  are cut   and the  2nd one is   settig up  overnight .  I'll finish   up tomorrow by running  a flush  trim bit  around the perimeter ( I purposely left it  a  hair wide this time)

More coming soon
-jay



django11

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Re: Captainhemo's OB-7 Build
« Reply #1 on: 18 Feb 2013, 11:24 am »
You are getting good at this!

 When you were thinking about getting either the x-ls or N3s I remember telling you to get the N3s as that would keep the upgrade bug away.  That didn't work!

Why did you decide to upgrade?

I am jealous by the way...

Captainhemo

Re: Captainhemo's OB-7 Build
« Reply #2 on: 18 Feb 2013, 05:42 pm »
You are getting good at this!

 When you were thinking about getting either the x-ls or N3s I remember telling you to get the N3s as that would keep the upgrade bug away.  That didn't work!

Why did you decide to upgrade?

I am jealous by the way...

Hehe,  I remember that as well.  To tell you  the truth,    I han't really  been    thinking of  upgrading... I had been  consdering  building a pair of X Statics just for something to build and possibly sell..  Then my folks (who had been considering a pair of X LS Encores) spent New Years over  here  and my dad fell in love with the N3's.  I kind of jokingly said,  "if you  want to buy them,  I can always build something else"  and  that was that  !
I really love the Neo3 PDR tweeter so I  wanted to stay with them.  I also  love the  tight, fast bass reponse of the N3's so  I figured I'd   try  the OB-7's 

-jay

NeilT

Re: Captainhemo's OB-7 Build
« Reply #3 on: 18 Feb 2013, 08:42 pm »
Looking good Jay, and thanks for the pics.

Neil

Ron

Re: Captainhemo's OB-7 Build
« Reply #4 on: 18 Feb 2013, 09:49 pm »
  I too think you are getting even better with each new build Jay. Can't wait to see the finished OB-7's and to read your opinion as to  how they sound. My guess is that they will sound absolutely fantasic!

doug067

Re: Captainhemo's OB-7 Build
« Reply #5 on: 18 Feb 2013, 09:52 pm »
I always wanted to build out these. Looks like fun, will be even better to listen too I presume. Good stuff!! Congrats

S Clark

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Re: Captainhemo's OB-7 Build
« Reply #6 on: 19 Feb 2013, 12:32 am »
Good choice on the OB-7s. They are a solid high end speaker with excellent clarity from about 65 Hz and up.  I spent a day with a pair that Nick77 brought to an Austin GTG.  They have a clear advantage over the N3 in clarity in dynamic passages, but may not reach quite a deep.  I have a pair of AV3 that are identical to the N3 up to the tweeter crossover- excellent bass response that goes a little deeper than the OB series. The OB-7s integrate very well with a sub for the bottom octave. 
Scott

Captainhemo

Re: Captainhemo's OB-7 Build
« Reply #7 on: 19 Feb 2013, 03:54 am »
Thanks for the comments guys.   I think the trick is   to make sure  we're always lerning  something from   previous buiilds which  there fore makes the next one  less complicated

Scott,  I am currently  running  a CSS quartet 10 sub (SDX10  + 2 10" PR's) and it works  very well with the N3's.  I am planning to send this over to my folks as well  so  I'm  planning on  doing one of Danny's servo subs to    team up with the  OB-7's.  The thing I liked best about the N3 bass response  is how   crisp and  fast it   is.  I find it very different from    what I've heard  previously .  Love it.  I'm  hoping the OB-7's   take that response to   another level  Really  looking forward to   hearing them   :D  Also  anxious to hear   increased clarity and detail in the OB-7s, should be amazing as I am already  impressed with the detail in the N3's

I received an email from Ron this  morning  with a few pictures of the first cross over  .   Because of my really  low vision,  Ron came up with a simple way  for me to adjust the  BMS which is most appreciated.   The frist 3 resistors are already connected   along with a "jumper wire"  I can conect addtional  resistors to .  Once  the speakers are broken in  and I have  the BMS set where  I want it,   I can make the connection permanent
Here are a few pics:







I also  did a bit more work to the bass cabinets this afternoon.    Got the rear  baffles all flush trimmed   and  sanded.  I'm  pleased with how the cabinets came out.  Definitely  a lot less sanding    and filling  than I had  when  I didn the N3's and the X LS Encores.
Hopefully  I will have the no res in the next couple of days and can  get these finished up




-jay
« Last Edit: 19 Feb 2013, 06:52 am by Captainhemo »

Danny Richie

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Re: Captainhemo's OB-7 Build
« Reply #8 on: 19 Feb 2013, 02:44 pm »
Looks good.  :thumb:  :thumb:

Captainhemo

Re: Captainhemo's OB-7 Build
« Reply #9 on: 25 Feb 2013, 03:03 am »
I've got enough no res to   do the   underside of the top plate of the bass cabinets but   there is only about an inch between  the top brace and  top plate  at the back   being that the  cabinets  have the slped tops.    Should I still do the top   even though the no res will basically touch the   brace at the  rear of the cabinet ?

There is not enough  no res to do any of the   lowest   area below brace H (cross over area)

I had to have the tops of the  cabinets cut off  as I discoverd the cabinets were  3/4" too tall and that 3/4" would interfere with the bottom woofer of the   OB section.   Had them cut off yesterday but go the new tops glued on today, trimmed , sanded    all fixed up :)



Some more pics coming soon


Thanks guys
-ajy

Captainhemo

Re: Captainhemo's OB-7 Build
« Reply #10 on: 26 Feb 2013, 12:38 am »
Here is a picture  of the new tops  and   the cabinets lined with no res.   One cabinet has the top  done,  one   not.   
Danny, does it mater that the no res is so close to the top brace?



One thing ...   the no res may be a little pricey but  wow, was it easy compared to  using the vinyl flooring,  OC Foam, and contact cement.  What a time saver and WAY less hassle.

-jay

Danny Richie

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Re: Captainhemo's OB-7 Build
« Reply #11 on: 26 Feb 2013, 01:26 am »
Quote
Danny, does it mater that the no res is so close to the top brace?

That's okay. You are damping the resonance of the top panel with that piece of No Rez. It has no brace.

Quote
One thing ...   the no res may be a little pricey but  wow, was it easy compared to  using the vinyl flooring,  OC Foam, and contact cement.  What a time saver and WAY less hassle.

You are not kidding. No Rez is really easy to install. And it works better than DIY methods.

Captainhemo

Re: Captainhemo's OB-7 Build
« Reply #12 on: 26 Feb 2013, 01:38 am »
That's okay. You are damping the resonance of the top panel with that piece of No Rez. It has no brace.

You are not kidding. No Rez is really easy to install. And it works better than DIY methods.

Thanks Danny.  Kind of what my gut said but I wanted to be sure.

The no res  seems very similar to  the  vinyl/PC foam.  The   rear dampening material on the no res seems     more rigid  and  more dense.

On to tyhe front bffles now   :)

-jay

Captainhemo

Re: Captainhemo's OB-7 Build
« Reply #13 on: 28 Feb 2013, 01:08 am »
Hi Folks

Here's  a bit more progress to report.

Finished off the no res installation as shown below.  I still have some vinyl left over from the  N3  and X LS builds so I may do the very bottom    in that as 2 sheets of no res doesn't quite do the entire cabinets.



Got all the cut outs on the  front baffles done   .  This ended up being a lot more work  than  I had planned  on. The baffles  are 1.5" thick   and  my straight cut bit only  has  1 1/4" cutting length so I had to make 2 passes on  each of the woofer holes.     After the 2nd plung , I ended up with   small reidge  in some areas of the  cut.    The only  thing I can  figure is that my  guide pin holes weren't  perfectly 90 degrees as I don't have a drill press.   
Anway, it made for a lot  of sanding to get  all the holes nice and smooth but   they  are all nice now.

Front view


Rear


Here's one  up close showing the 7/8" ron over.   Doesn't show up overly well in the pctures but  it turned out good


Will hopefully get some more done in the next  coule of days

-jay

PDR

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Re: Captainhemo's OB-7 Build
« Reply #14 on: 28 Feb 2013, 01:28 am »
I really enjoy these DIY build threads.
This project looks like its gonna turn out very nice.
Its priming me for an X-statik for the living room build I'm gonna do this spring.
Would love to build the 7s but wife wont let me go any larger..... :nono:

Keep posting pics of the build please, I'm enjoying it immensely!

Captainhemo

Re: Captainhemo's OB-7 Build
« Reply #15 on: 28 Feb 2013, 01:42 am »
I really enjoy these DIY build threads.
This project looks like its gonna turn out very nice.
Its priming me for an X-statik for the living room build I'm gonna do this spring.
Would love to build the 7s but wife wont let me go any larger..... :nono:

Keep posting pics of the build please, I'm enjoying it immensely!

Hey Pery,
I always lover reading them as well.  I actually    had considered not doing a thread this time but then  thought about how much  I enjoy reading them convinced me to  go ahead and do it.

I am happy  with how they are turning out so far, still not 100% sure on how I am finishing them.  Have a couple ideas .

When you  say "won't let you go any larger"   are yo meaning size or $$ ?   The X statik is 49" tall ,    the OB-7 is 49.5" and is actually .5"  narrower too.  X Statiks are  .75" deeper.

-jay

gregfisk

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Re: Captainhemo's OB-7 Build
« Reply #16 on: 28 Feb 2013, 02:25 am »
Looking good Capt. I also really enjoy the build threads, it's one of the reasons I hang out here. That and all of the learning that happens while reading here. Keep up the good work and keep us posted!

Greg

PDR

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Re: Captainhemo's OB-7 Build
« Reply #17 on: 28 Feb 2013, 03:13 am »
Hey Pery,

When you  say "won't let you go any larger"   are yo meaning size or $$ ?   The X statik is 49" tall ,    the OB-7 is 49.5" and is actually .5"  narrower too.  X Statiks are  .75" deeper.

-jay

No I meant size wise.....I've never compared the physical dimensions, I just assumed the 7s were larger......hhmmmm.

I think I'll try the X-statiks, the price point on the sale kits are hard to beat....I have a few friends that are keen to hear them as well.
I'll prob build a kit or even 2 in the next year......its a sickness...so if I like the Xs I might give the sevens a go.
There is an audio club that meets here once a year, well they met last year and one is planned for this year...
There were some DIY offerings last year....they were a great hit, everyone loved them.....in the back of my mind all
I could think of was bringing my Vs........they were soooo much better. This year I'd like to bring something, the Vs weigh too much,
but the X-statiks might go over well.....sickness I tell you..... :wink:

Captainhemo

Re: Captainhemo's OB-7 Build
« Reply #18 on: 2 Mar 2013, 01:53 am »
Here is a bit more progress.  I've been waiting for a slot cutting bit in the mail   to cut the slots for the  wires in the OB section so I thouhgt I'd   get the grill frames   done.

First off,     got the pieces cut  and  then rounded off  edges all the way around with a 3/8" radius  bit.



After marking out all the hoes  I began routing by recessing all the  holes  .25"   at a diameter of 6.375".  After a couple passes  on each hole w, I  cut out all the holes to 5.5".   The pieces between the   2 OB woofers and the   4   lower  woofers will be removed.



Used  a long piece of  MDf for a guide to  use my flush trim bit   to remove the   remaining pieces.  When everything  goes as planned, you get this



When things don't go so well,  you get  something like this one



Note the lower right side...  Guess I didn't clamp the  guide tight enough and when I was  triming out  those lower pieces it started to slide  until finally near the bottom, it  really slipped and  I ended up witha   real narrow spot.
Once the frames are painted back  and wrapped in black cloth I'm hoping it won't be  too noticable.  very disappointing

The slot cutting bit arrived this afternoon   so I'll be able to finish off those baffles

-jay   


Captainhemo

Re: Captainhemo's OB-7 Build
« Reply #19 on: 6 Mar 2013, 01:57 am »
Here are a few more pictures.

Finished up the grill frames and painted them black.


Here's the pair, used a bit of wood filler to   fill that gouge  but   it is still  narrow  on the bottom right.   I don't think it wil be noticable   once the  grame is wrapped in  black cloth.


After finishing those up, I moved onto the front baffles again as both my slot cutting bit and the 3/4" roundover arrived.
Cutting a 1/4 x 1/4 slot around the circumferance of the  lower woofer in the OB section to run the wires to the tweeter and the top  woofer.  (saw this on Neils OB7 build thread)


Next  had to drill some holes between  the  different drive cut outs to   get the wires from one section  to the next.  There are also 4 holes going  from that slot down  into the lower   cabinet .


After finishing up  that on both baffles  I  did a 3/4"  round over on   the left and right outside edges  and across the top.  I'll  also do the  back edge once its  glued to the lower cabinet.


A little closer


Sorry the photos aren't better,   the lighting in my garage  is  poor

-jay