I'm attempting my first cabinet build....be gentle.

**valhallax** · November 28th, 2010, 10:31 PM

i think i read somewhere that the six moon guys got the design from a great guy..i wonder if he was compensated for his designs? but im sure if he designed it..it's great. which model 604? for what its worth.. i did some folded horns in 20 coats of black laquer, and i can see every little imperfection. i then built an entertainment center and used "polyshades" its a black stain and polyurethane by minwax..2 coats and it was awsome. tho, black shiny things do show everything so due diligence is required for a nice outcome. it looks as if your off to a great start! i think i remember another poster here building the same sort of cab. i think he was having problems getting alot of bass, but i think there was a crossover issue? the other members will chime in im sure.

**cradeldorf** · November 28th, 2010, 10:44 PM

Originally Posted by valhallax

i think i read somewhere that the six moon guys got the design from a great guy..i wonder if he was compensated for his designs? but im sure if he designed it..it's great. which model 604? for what its worth.. i did some folded horns in 20 coats of black laquer, and i can see every little imperfection. i then built an entertainment center and used "polyshades" its a black stain and polyurethane by minwax..2 coats and it was awsome. tho, black shiny things do show everything so due diligence is required for a nice outcome. it looks as if your off to a great start! i think i remember another poster here building the same sort of cab. i think he was having problems getting alot of bass, but i think there was a crossover issue? the other members will chime in im sure.

Thanks Valhallax, It sounded like a lot of great people were in on the build. My guess is his reward was an awesome job well done. I have one 604 C and one 604 E that are going in them as soon as they get back from GPA (totally jonesing over here!!!)I'm also getting new GPA crossovers for them since the C has a 1600 network and the E has a 1500. That sounds kinda like the 6 moons article they couldn't get good bass and it turned out the crossover was wired wrong. I'll look into the polyshades thing since I'm polyurethaning them now anyways. I still don't understand what made the 6 moons speaker an MLTL? unless they didn't show a final inside picture.

GM · December 4th, 2010, 01:19 AM

Originally Posted by cradeldorf

I still don't understand what made the 6 moons speaker an MLTL? unless they didn't show a final inside picture.

The inside is just a box with some bracing and an above average driver support.

Any cab with a high enough aspect ratio to no longer have an air mass of ~uniform particle density that's required to be a reflex (Helmholtz resonator) is technically a MLTL, though if its 1/4 WL TL pipe action isn't strong enough to shorten the vent's reflex length, then it's actually in-between the two acoustically speaking. IIRC, this one just barely qualifies for MLTL status.

GM

**Ronald Lee** · December 1st, 2010, 03:20 AM

Originally Posted by valhallax

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i think i remember another poster here building the same sort of cab. i think he was having problems getting alot of bass, but i think there was a crossover issue? the other members will chime in im sure.

I think the 604 is similar to a 146? Altec published a booklet that showed how to tune a port. I believe Altec use a something called "impedence peak matching." Pretty simple to do, all you need is a small amplifier, a audio tone generator and a VTVM.

**cradeldorf** · December 1st, 2010, 04:24 AM

Well I'm certainly willing to listen to porting options for these, right now they just have 10 inch holes because thats all the smaller my circle jig would go. The bottom boards are removable so I can replace them if need be. I have no idea what the proper port size would be on these. : / I bought some poly fill for them today I'm going with about 1 lb per cu ft so about 5.75 lbs per cab.

**Ronald Lee** · December 1st, 2010, 04:35 PM

cradeldorf: Okay, I found that manual. The name of the Altec manual is "LOUDSPEAKER ENCLOSURES - Their design and use." Altec publication AL6030-1. This manual has advice on how to tune and adjust your port size. I built a box using these recommendations, and it works pretty well, considering you don't need any real engineering knowledge.

Here are .JPG images of the manual:
1974 Enclosure Manual

**cradeldorf** · December 1st, 2010, 10:25 PM

Thanks Ron I'll check it out. : )

**cradeldorf** · December 2nd, 2010, 05:37 AM

Looks like I'm gonna go with plan "B" cover them with fake Ostrich skin Naugahyde. the gloss black was really a bad idea. :doh:

GM · December 4th, 2010, 01:06 AM

Originally Posted by cradeldorf

the gloss black was really a bad idea.

High gloss Wilsonart laminate is your friend here...........

GM

**westend9** · December 2nd, 2010, 05:42 AM

Originally Posted by cradeldorf

Well I'm certainly willing to listen to porting options for these, right now they just have 10 inch holes because thats all the smaller my circle jig would go. The bottom boards are removable so I can replace them if need be. I have no idea what the proper port size would be on these. : / I bought some poly fill for them today I'm going with about 1 lb per cu ft so about 5.75 lbs per cab.

For the port, you could use the same "copywrited" system that Srajen used, put a screw through one edge of your 10" cutout and secure it just to the outside of the port. The cutout circle can be turned to block some or none of the port. Don't worry about infringement because his is a little different

.

Edit: whoops, saw that your cabinet is not too big where the port is, change that 10" circle to two 5" circles or cut the 10" to fit.