[jdbrian]

Thanks Drphoto

Man, those don't look good....they look freaking awesome!  I think you've got a retirement career as a speaker builder if you wanted.

Personally, I like 'em without the grill. That baffle is just too pretty to cover IMHO.
  Those baffles were a lot of work. They are maple but the corners(3/4" round over) are actually popler as it matches the maple color almost perfectly. Maple would have looked darker where it was rounded over and I thought it would not look as nice as the closer matched color.  I am eligable for early retirement in a couple of years but I don't think I would want to build speakers for a living. I have a ton of respect for those who do. Woodworking and DIY audio stuff are lifelong hobbies of mine. I actually work in the medical electronics field (diagnostic lab equipment) so I do a lot of electronic, electrical and mechanical work for a living.
  Some of my other projects are in the gallery here. The tube amp is still under developement.  http://www.audiocircle.com/index.php?action=gallery;area=browse;album=3028

Brian if your open to more diy you might consider the classD Audio amps, long thread in cheap and cheerful. I have one of the Super series at 125 wpc hooked up to my 7's and they are singing like never before. Hope to throw one of the diy Dodd buffers in front of it soon. 

Nick , I have been looking seriously at the wyred4sound amps and was also thinking that they could be warmed up a bit with the Dodd buffer if required. Do you have a link to the amps you are referring to?

Thanks
Brian

[Nick77]

http://classdaudio.com/index.php/class-d-amplifier-kits/sds-254-kit.html

http://www.audiocircle.com/index.php?topic=76400.msg783731;topicseen#new

These amps were compared to some high dollar commercial amps with very positive results.

[NeilT]

Hi Brian,

Just starting to build my OB7 Xovers. 
Do you or any other OB7 owners have pictures of your Xover layout?
Would love to see em.

Thanks
Neil

[sl_1800]

They look great with the grills.

[jdbrian]

Hi Neil

  I do have some pictures somewhere. It was a real tough job to fit it all in. As you see from the pictures I have the bass management installed on the back wall between braces. Trying to separate the coils and keep their orientations at right angles is the biggest challenge. You need to think about stacking some components vertically so they take up less real estate. I tried to connect everything directly with the component leads but ended up with a couple of pieces of wire to connect some parts. I used some terminal strips(soldered) and some may frown on that but I have found after 30yrs of working on electronics that having good physical support for connections where they leave the circuit board is necessary for long term reliability. This is particularly true if you plan on going in to tweek the crossover in the future. I'll see if I can find those pictures.

Brian

[NeilT]

It was a real tough job to fit it all in. I have the bass management installed on the back wall between braces. Trying to separate the coils and keep their orientations at right angles is the biggest challenge. You need to think about stacking some components vertically so they take up less real estate.

Does anybody use the bass management?
I was thinking about using 1 inch stand-offs to support a piece of ¼  inch MDF. That way I could mount stuff on both sides.

I'll see if I can find those pictures.

Looking forward to it and thanks Brian.

Neil

[jdbrian]

Hi Neil

   I found a couple of pictures. As you can see I used a piece of 1/4" thick peg board to mount the components. I still had to drill a few holes to get everything mounted. It isn't that easy to see but I used 2 terminal strips. One is mounted on the small piece of peg board on top of the large coil on the left. The other is on the right side just below the sonicap. I set up mine with 2 sets of posts so the woofer circuitry is completely isolated from the tweeter/mid Xover. One thing to note is the polarity of the woofers. Make sure you follow the schematic as they are connected reversed to the tweeter/mids. If you want a higher resolution picture send me a PM.
  Note also that I made some changes in the base and bottom that created a larger space for the crossover than the stock plans. I think it was 1 inch longer.
I used electronic grade silicone to glue the components down. However GE silicone 2 which you can get at most hardware or home improvement stores seems to be identical to the GC electronics stuff I used. It does not produce acetic acid when curing.
Need more info. Let me know.
Brian

[NeilT]

Thank you Brian.
The pic is great and helpful, you did a real clean job.

Neil

[newportcycle]

Very neat job Brian, I dislike making up crossovers the most.  I just dont seem to have a good imagination for putting the things together.  Cant wait to see your final results Neil, the progress youve made so far is exceptional.

[Danny Richie]

Nice lay out. I don't recommend the terminal strips though. There is no good reason to put that in the signal path. Also, I am not sure what the Black wire is that is connecting some of the parts. The kits come with some really high quality internal wire. 

[Danny Richie]

Just as an example...

This is not a standard OB-7 network, but it does use a similar upper MTM section. I had no real size restraints as this was mounted external. So it is not real compact.



I try to wire everything point to point without using any additional wire if possible. The only wires that will connect anything within the crossover is the negative legs that return back to catch just the right points.

Everything is twisted then soldered.

All inductors, capacitors, and resistors use tined wire (coated to seal the Copper). So no heat shrink is used in those areas. Anywhere the high purity OFC wire is used is sealed with heat shrink.

Parts are mounted on 3/8" thick MDF. I zip tie them then used some hot glue on them as these networks were going to see some shipping abuse. There is also clear Silicone under the big inductors. This much effort in holding it all in place is not necessary in most cases.

[dvenardos]

Danny,
   I know you are super busy, but a picture of a built crossover in the instructions along with a cut list for the wire would be extremely helpful for novice builders.

[Danny Richie]

I am going to work on that.

I am also going to start a new thread just on crossover construction.

[NeilT]

Thanks guys, for all the feedback.
There are so many details to figure out and this forum really helps to smooth out the road for a new guy.

Neil

[jdbrian]

Nice lay out. I don't recommend the terminal strips though. There is no good reason to put that in the signal path. Also, I am not sure what the Black wire is that is connecting some of the parts. The kits come with some really high quality internal wire. 

Hi Danny

 The strips are there for mechanical strength. The internal wiring is quite stiff and puts some stress on the connection when you open it up to work on the crossover. I also had some temporary 3 ohm metal cased resistors in there until the ohmites arrived. When wiring the strips I tried whenever possible to have the 2 wires in direct contact so that the current isn't actually flowing through the terminal strip but the strip is supporting the wiring assembly. After all the speaker drivers themselves use a terminal that you solder to.
  The black wires you see are actually heat shrink tubing that is covering the long ends of coil wires etc. to prevent any shorts. I found some of the coil ends had insulation that was fragile. It looks like they had been heated to remove the insulation where the ends were tinned. The insulation was fragile and easily scraped off in the areas next to the tinning so I insulated them to prevent any problems.
  It is a pretty tight squeeze getting it all in there. I do worry about crosstalk from the bass coil to the large mid coil. I am going to check for crosstalk when I get a chance. I can disconnect the mid/hi section and short the terminals with a low value resistor to simulate the damping of the power amp then drive the bass section and see if there is any signal on the mid's.

Brian

[Danny Richie]

The strips are there for mechanical strength. The internal wiring is quite stiff and puts some stress on the connection when you open it up to work on the crossover. I also had some temporary 3 ohm metal cased resistors in there until the ohmites arrived. When wiring the strips I tried whenever possible to have the 2 wires in direct contact so that the current isn't actually flowing through the terminal strip but the strip is supporting the wiring assembly. After all the speaker drivers themselves use a terminal that you solder to.
  The black wires you see are actually heat shrink tubing that is covering the long ends of coil wires etc. to prevent any shorts. I found some of the coil ends had insulation that was fragile. It looks like they had been heated to remove the insulation where the ends were tinned. The insulation was fragile and easily scraped off in the areas next to the tinning so I insulated them to prevent any problems.
  It is a pretty tight squeeze getting it all in there. I do worry about crosstalk from the bass coil to the large mid coil. I am going to check for crosstalk when I get a chance. I can disconnect the mid/hi section and short the terminals with a low value resistor to simulate the damping of the power amp then drive the bass section and see if there is any signal on the mid's.

Ah, there is more there than meets the eye. You did good.

I don't think you'll have any problems with those inductors from they way you have them turned.

[jdbrian]

Thanks Danny
Man, I spent a long time trying to get everything optimized in the layout, wiring etc. In the end you need to make some compromises due to tight space. It is definitely not a job you want to hurry. Some sort of double deck arrangement may make it easier but you would need to make sure you have the height in the box bottom. Those boxes are impressively dead. All the bracing and no rez really pays off. There is none of the typical box coloration and when you first hear them they seem lean in the mid bass. But after you listen carefully you realize you are hearing more detail and not the thrumming of the box that is so typical.

Brian

[Danny Richie]

All the bracing and no rez really pays off. There is none of the typical box coloration and when you first hear them they seem lean in the mid bass. But after you listen carefully you realize you are hearing more detail and not the thrumming of the box that is so typical.

You are very correct. Now if I can just get everyone else to understand this value.