OB W-frame build

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jimbones

Re: OB W-frame build
« Reply #20 on: 14 Feb 2017, 02:06 pm »
Uh maybe I am missing something but wont it be difficult to screw in the drivers? How would you get a tool in there to work?

Danny Richie

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Re: OB W-frame build
« Reply #21 on: 14 Feb 2017, 03:17 pm »
Don't make the brace any deeper than half of the depth of the V.

bdp24

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Re: OB W-frame build
« Reply #22 on: 14 Feb 2017, 10:18 pm »
Uh maybe I am missing something but wont it be difficult to screw in the drivers? How would you get a tool in there to work?

I used bolts and nuts in my W-frames, not screws. I don't trust MDF to hold under the weight of the woofer hanging almost upside down!

aceinc

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Re: OB W-frame build
« Reply #23 on: 20 Feb 2017, 02:19 am »
Someone asked for pictures.


Here are some of the pieces and a large woofer. Note the lines on the pieces I did that to make sure where everything went, and later used it for a screw pattern.


Here is one inner cabinet put together with the paint I chose for the interior. A couple of things about the paint;

1) I chose the smooth as opposed to texture finish.
2) They couldn't make Black, so I got dark gray. I could probably have asked them to put more black tint in it, but it was Sunday at HD.
3) It is like painting with pudding.
4) It seems to fill well.
5) I have been painting with a brush, and then using a small roller to smooth it out.


Here is the inside of the inner cabinet after one coat.

I messed up a few things on the other inner cabinet, and it needs some bondo work before painting. I'll post those later.

mlundy57

Re: OB W-frame build
« Reply #24 on: 20 Feb 2017, 02:38 am »
Looks pretty good.

Ahhh Bondo and wood filler, what would we do without them  :lol:

Mike

aceinc

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Re: OB W-frame build
« Reply #25 on: 6 Mar 2017, 02:06 am »
I have the outer cabinets installed. Basically 3/4" MDF on top, bottom and sides.

I bought the wood, but decided against the center brace. My thought process was that with 1-1/2" of material on the sides of the cabinet there should be no resonance in the band pass. My very unscientific knuckle test seems to confirm this. Also when I only had the single side pieces, I wedged a piece of 1"x 4" in the area brace would go. When I did the knuckle rap test, it made no difference in the sound, which did seem like it would be in the band pass.

The next step is to get everything prepped for veneer. I will need to sand & fill a few areas to ensure everything is smooth.

aceinc

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Re: OB W-frame build
« Reply #26 on: 10 Mar 2017, 12:54 am »
Today's questions are about veneering.

I have a 4'x8' sheet of red oak veneer (non paper back) and 25' of 7/8" iron on red oak banding.

Question 1, on this type cabinet does the banding go on 1st? My thought is yes, so that if the cabinet is dragged on carpet the banding doesn't snag and break off.

Question B, Should I try 45 degree corners on the banding, or butt joints?

Question 3, Does anyone live in South Florida that knows what they are doing and want some Fat Tire beer, in exchange for technical assistance?

aceinc

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Re: OB W-frame build
« Reply #27 on: 3 Apr 2017, 12:50 am »
Well I did what I thought was best veneering wise. Mixed up a batch of stain that I likedpainted/rubbed in the stain, and shot it with a coat of satin polyurethane.

Maybe by next weekend, I will have the speakers mounted and everything all buttoned up.

Against Danny's recommendation, I will be mounting the amplifiers on the back of the cabinets. I have built "boxes" that has an open "back" (facing the driver) that will hang off two rails situated on the backs of the enclosures near the bottom.

The problem that was identified with mounting the amps to the cabinets is the vibration of the cabinet will interact with the amplifier. I also felt that blocking some of the air flow of the lower woofer would load the back of that woofer. However in this case aesthetics wins out over pure audiophile-ness. I will screw and not glue the rails, so if I change my mind I can remove the amp.

aceinc

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Re: OB W-frame build
« Reply #28 on: 4 Apr 2017, 10:34 pm »
Wiring finally

I am fittin' (as they down south) to install all the goodies in the cabinets. I realized that I haven't a clue how to wire everything up. Would someone point me to where I can finding the wiring diagram for a dual 12" A370 based W cabinet OB system.

Also any pointers on the best place to drill the hole for the wires to go through the baffle would be good as well.

ebag4

Re: OB W-frame build
« Reply #29 on: 4 Apr 2017, 11:15 pm »
I "believe" the "W"and "H" frames (with drivers firing in opposite directions) will wire the same.  Below is Danny's wiring for the "H" frame.



Best,
Ed

PDR

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Re: OB W-frame build
« Reply #30 on: 5 Apr 2017, 12:10 am »
So if you want to make the drivers face the same way .....you only switch the driver wiring? or the driver and servo?
or what?

aceinc

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Re: OB W-frame build
« Reply #31 on: 5 Apr 2017, 12:13 am »
So if you want to make the drivers face the same way .....you only switch the driver wiring? or the driver and servo?
or what?

Just a guess, but based on the wiring diagram, just the power leads, not the servo leads. My gut reaction is that switching the servo leads would cause some form of cancellation.

Danny Richie

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Re: OB W-frame build
« Reply #32 on: 5 Apr 2017, 12:20 am »
If they face the same way then you have to flip the polarity on both the driver coils and sensing coils to common polarity.

aceinc

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Re: OB W-frame build
« Reply #33 on: 5 Apr 2017, 12:26 am »
So in the drawing above, on the top driver only you would switch black & red on both sets of terminals, correct?

Or on the bottom driver only.

l like being wrong, it means I learned something. I am learning all the time.

Danny Richie

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Re: OB W-frame build
« Reply #34 on: 5 Apr 2017, 12:58 am »
So in the drawing above, on the top driver only you would switch black & red on both sets of terminals, correct?

Only if you flip the top one around so that it too faces the other way.

Quote
Or on the bottom driver only.

l like being wrong, it means I learned something. I am learning all the time.

If you flip the bottom one then flip the polarity on it (both terminals).

Just make sure the driver coils are in parallel and the sensing coils are in series.

aceinc

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Re: OB W-frame build
« Reply #35 on: 5 Apr 2017, 01:04 am »
Sorry, yes I was describing how to wire if the speakers were facing the same way.

Captainhemo

Re: OB W-frame build
« Reply #36 on: 6 Apr 2017, 12:20 am »
Easiest way to remember   the wiring for these (H/W frames) is   wire  forward facing  woofers in phase, rearward facing woofers out of phase.  Driver coils are always in parallel,  servo coils always in  series

jay

aceinc

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Re: OB W-frame build
« Reply #37 on: 6 Apr 2017, 12:00 pm »
I have the drivers in one cabinet.

Two lessons learned (the hard way of course);

1) Drill the holes for the wires before painting.

2) Put the driver facing the bigger opening (the single opening) in before the driver facing one of the two smaller openings. This will make it easier to get to all of the screws.

A few questions;

What is the reasoning for facing the drivers in different directions in the "W" frame?

Is there a significant disadvantage to putting ball casters on these boxes? After putting the drivers in, these cabinets are darn heavy.

Danny Richie

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Re: OB W-frame build
« Reply #38 on: 6 Apr 2017, 01:39 pm »
They play the same either way you face them.

Careful of putting wheels on them. I know it makes them easy to roll around, but you really want them to not move when they are playing. The more solid the better.

Captainhemo

Re: OB W-frame build
« Reply #39 on: 6 Apr 2017, 04:05 pm »
When you face the woofers all in one direction, a majority of th weight is  on  one side of the baffle and depending on the base you used,  the offset can make the cabinet a bit  more  "tippy".
I have all the woofers facing forward in my slpped triples, the base is   only extended by approx  2.75".  If you push onthe cabinet, it tiltts easier towards the rear but it is not  unstable.  With duals  in w-frames,  I'd imagine it would be even less so,   less weight and  it's clsoer to the center of the cabinet.

I picked up some 8mm casters off ebay that I use in the shop for rolling   cabinets around etc. Sometimes I'll use them in the room just for  setting up  but  once  I get stuff where I want it,   it all gets spiked

Sort of goes against  what I believe but at some point, I really want to try  a pair of the Isostandsthe Corndog and a few others have talked about

jay