828 configurations

[dancing-dave]

I've got some 511 horns on the way and am ready to begin building up a pair of 828 cabinets for a stereo VOTT set up. I've noticed that the horns can either be fitted on top of the 828 with the bass port on ground level, or.... with the horns inside of the port space and the cabinets either elevated with the horns lower, or on the floor with the woofer at ground level.

What are the characteristic differences between these configurations?

Thank you for any input on this.

(Also, does anyone know how to do a grand piano laquer finish?)

[Fitts]

Either way the system will sound great. The WAF is generally higher with the horn inside and a nice grille cover. Black sheer nylon for a black piano finish might be nice. For a piano type finish consider having an auto body shop spray the cabinets after you seal and sand them and before you put any wires or electronics in. If you get a good shop they should be able to give them that glassy smooth wet paint look of a polished piano.

My 2 cents worth,

[djnagle]

I did high gloss laquar(sp) finishes for years on custom motorcycles....could do them in my sleep. Today we use House of Kolor polyurethan(sp) for that finish. WIth laquar you spray on a coat, let it dry and lightly wet sand it. Repete this step 20 times (no kidding)after the last coat you wet sand it with 1500 to 2000 grit sand paper then polish it with auto polish. With urethan you do the same thing but with only two coats because it is much thicker. You sometimes have sags and runs but they can be leveled out with careful wet sanding. Good luck.

[Roland N R]

My Favorite 828 configuration is with a modified 604 loaded in place of the the 416/515. The 604 has a replacement coaxially mounted 800 cycle oval horn. The bottom vented space is converted to a JBL 2445 subwoof XO at 160 Hz.

You get the best of all worlds!!!!!

[thevott]

Nifty. I'd like to see a picture of that one.
thevott

[boltupright]

Hey Roland; For experimentation, I put a 604 8G in a A7 cab & it sounded like poop!What did I do wrong? I used the 604 8G crossover,is that where I went wrong?

[Roland N R]

Don't know what poop sounds like? The 604 provides fantastic MR but you will have difficulty with lows if played straight w/o sub.
This combo gives deep powerfull bass,accurate mids and good highs in a "small cab" for a 105 db efficiency. Unlike the 604 by itself XO at 1600Hz there is no beaming and bass is plenty. You need biamping of course.

[Fitts]

Hi Boltupright,

I think what Roland is saying will require more work than just bolting your 604 into the A7 cabinet. You also need to add a solid panel inside the cabinet that reduces the volume of air behind the 604. A solid plywood panel put in the cabinet that seals from front to back and side to side placed just below the sloping panel that makes up the horn should be about right.

Happy Holidays,

[boltupright]

Hi Dave; Thanks for the reply! What I did was,useing a hole saw I cut a hole in a piece of 3/4 ply the size of the back panel,& drilled the size of hole that would accomidate for the horn driver.I used high density foam & created a seal on the woofer's alinco magnet,it was a tight seal.I used the 604 8G cossover & It sounded lousy,so I s******* the idea.