Altec 605b Duplex, now what?

[kyle]

Rear mount or cut notches all the way around the opening. The flange is narrow on the back so you won't have too much edge distance for fasteners.
Rear mount is best for Altec 15" frames.

 

[marantzfan]

Drivers are back and I'm only waiting on one resistor to start building the crossovers.

 

[marantzfan]

Crossover layout

Ok, I think I have the crossover layout figured out. Anyone mind lending an eye to double check my work?

Here is the original schematic:

http://home.earthlink.net/~jmarkwart/sitebuildercontent/sitebuilderfiles/605a_brev1.pdf

Attached is a sketch I did of how I am planning to layout the crossover on the board.

 

[marantzfan]

Anyone? :ntwrthy:

I would really appreciate it. This is my first time laying out a crossover from a schematic and I would feel a lot better if I had a thumbs up from someone that knows this stuff better than I before I start slinging solder.

 

[RayW]

Assuming the squiggle at the end of the 4.7uF cap means that it is connected to ground and the W-, it looks good to me. :thmbsp:

 

[marantzfan]

Assuming the squiggle at the end of the 4.7uF cap means that it is connected to ground and the W-, it looks good to me. :thmbsp:

Awesome, that is what that squiggle means. That's the 4th layout I did, each time realizing that I could make shorter connections.

Now, the only thing I need to figure out is how to wire the L-Pad. On markwart's webage he states:

Potentiometers

If a 25 or 30 ohm potentiometer is hard to find, one-half of an 8 or 16 ohm L-Pad can be substituted by utilizing the 30 ohm element with the center wiper, and leaving the other element un-terminated. Most L-Pads also switch to open circuit after reaching the 30 ohm limit, which would effectively give you an added zero dB attenuation position for the Mid Freq EQ.

How exactly is the above wired then, considering L1 and L2 from my diagram above and the 1,2,3 terminals on an Lpad. :scratch2:

 

[RayW]

Wire up to 1 and 2 on the pad. If the tweeter gets quieter when you turn it to the right then change to 2 and 3.

 

[marantzfan]

Wire up to 1 and 2 on the pad. If the tweeter gets quieter when you turn it to the right then change to 2 and 3.

If it makes a difference, here's the Lpad I'm using:

http://www.parts-express.com/pe/showdetl.cfm?partnumber=260-250

BTW, thanks for getting me straightened out here in such short order Ray! I owe you one.

 

[RayW]

I think it's 2 and 3 on a standard pad like that but I generally just hook it up and try it. It will accomplish the same thing either way with the only difference being which way the knob turns to make the tweeter louder.

 

[marantzfan]

I think it's 2 and 3 on a standard pad like that but I generally just hook it up and try it. It will accomplish the same thing either way with the only difference being which way the knob turns to make the tweeter louder.

Does it matter which lead goes to which terminal?

 

[kyle]

When I did mine for my 604-8Gs, I did it so that they could be bi-amped if the urge hit. You can do it by running the minus side as two continuous wires connecting the components. The input end can be jumpered or connected to one post.
Physically, mine look almost like the schematic from Mr. Markwart.

 

[theebadone]

Now go find yourself a Scott 299 stereomaster and be ready to (really) start enjoying all of your favorite music.

 

[marantzfan]

Now go find yourself a Scott 299 stereomaster and be ready to (really) start enjoying all of your favorite music.

Already have the amplifier picked out; Bottlehead Stereomour SET 2A3.

 

[RayW]

Does it matter which lead goes to which terminal?

Not in this application. It'll just be acting as a variable resistor, no polarity involved.

 

[marantzfan]

Well, here's what.

I've built some 620 style cabinets based off of the plans made available by Wardsweb and Watt in this thread, with a few minor differences:

http://www.audiokarma.org/forums/showthread.php?t=440547

Crossovers were built using the Markwart 605 Crossover plans with MF EQ. Parts used were Kimber Kaps, Jantzen Air Core Inductors and Mills Resistors. Wiring is all done with CAT5 twisted pairs as I want to try thin gauge with with these and my SET 2A3 Bottlehead amplifier.

Cabinets were built with 3/4" furniture grade Red Oak plywood and are mitered at the corners. I didn't want to mess with veneering so much surface area but in hindsight I think I would have done these in 3/4" MDF and then veneered them as you can afford to make a few mistakes that way.

For now, all I have are some Iphone pictures that I took along the way. Once I get them inside I'll get some better quality pictures.

All of this was done during the heat of summer here in Phoenix mostly on days of 109+ weather. I'm surprised the oil was able to penetrate the wood with the amount of sweat these have in them (literally).

 

[marantzfan]

Looks like these are coming into the living room tomorrow. One... More.... Night...

 

[Cactus Bob]

They look very nice Anthony. Enjoy! :thmbsp:

I know a guy out your way that does great finishing work. :yes:

 

[sebrof]

Wow, very nice. Can't wait until you tell us how they sound, especially with the Bottleheads.

 

[Jailtime]

Those cabs are beautifully built and finished. :drool:

 

[doucanoe]

Those turned out very nice Anthony! I think you are going to get quite a bit of fun and enjoyment out of them.


RC