Altec 604e mounting question

[Feral Kid]

Hi,
I am building a pair of cabinets for my 604e’s. A DIY Stonehenge V is what I'm aiming for. I have a question about mounting these speakers. I’ve noticed that mounting the speaker from the front creates a problem. The small gusset (s) on the frame prevents the speaker from sitting flush when mounted on the front of the cabinet. This is due to the limited area fasteners need to clear the baffle hole. I have looked at a lot of pictures of completed cabinets on the web. Unfortunately, they have left me confused. Do they cut 16 groves around the speaker hole to allow a flush fit? I don’t think the drivers should sit on these gusset (s) and float above the cabinet. If I mounted the drivers from the rear this would eliminate the problem and it would sit flush. This would be structurally sound for a driver this heavy. I want to do what best for sonic quality while supporting structural integrity. Any suggestions would be greatly appreciated.

 

[kyle]

Mount them on the back of the baffle. If you see other cabs with 604s mounted the front of the baffle , they either have newer style 16" frames or the people have cut notches in the baffle to allow the frame to sit flush.
I had a pair of 604Es and built cabs with a removable baffle section so I could try both front and rear mounting. I couldn't tell the difference and the rear mount gives you more frame contact area than the front mount does. The cone has a very small amount of movement so even if you make the opening 13 3/4" instead of the recommended 14 1/8" you will not have any issue at all and you have enough space to use tee nuts or through bolts if you want. It's a good idea to slightly bevel the opening so you don't cause anyone to ridicule your choices.
I like that the Stonehenge fits in a room more easily than a 620 style cabinet but the 620 provides a nicer midrange due the wider baffle. You could also search at DIY Audio for a variety of MLTL cabinets that get more and better bass and have a similar profile to the Stonehenge.

 

[toddalin]

I've seen them mounted to the front with lots of caulk, tightened down hard on a pair of Super Big Reds on press-board. My Super Big Reds (oak) have the 16" 604E2s mounted on the front.

Someone with a large format 3D Printer should go into the market of making a spacer to accomodate the gussets. I had thought about it when I had access to a laser table, but a 3D printer would allow for the groves to "angle down" whereas the laser cutter would just leave the notches that the gussets would sit into.

There are places that will make what you design and this would be a simple project using DesignSpark Mechanical (free download).

 

[kyle]

Toddalin, I've seen photos of your speakers previously and wondered about the 604s. They appear to have the narrow mounting edge that regular 15" 604Es do instead of the wide edge of later 16" frames and they look to be white.
Did Altec make a 16" frame with the narrow mounting edge?
Here's a 604-8G with the wide mounting edge 16" grey frame:



This is interesting because I just did a Google search for 604-8G and this image came up. I did a double take because that's my carpet so this is actually my old 604s at my old house in Vancouver.

 

[twiiii]

Maybe you should trade them for a pair of 904's. But if you prefer Alnico magnets I guess you need to cut some grooves. You might want to use a much thicker front baffle board. But I doubt you will notice much difference in sound with the speaker mounted from the rear as most of the important frequencies that define imaging and staging come from the tweeter not the woofer cone.

 

[twiiii]

If you had the HPLN version then you would make the system a 3 way using the smaller Alltec 311-90 with a 291-16 b driver crossed at 400 and 7000 hz with an additional 416 woofer added around 60 HZ using a 1st order passive crossover to blend with the 604 woofer. Its a great sound especially if you tri-amp. But to keep it simple ,mount the woofer from the rear and use a large cabinet so you don't have to port the woofer. I detest ports. Especially if you want to reach down low to 30 HZ.

 

[toddalin]

Toddalin, I've seen photos of your speakers previously and wondered about the 604s. They appear to have the narrow mounting edge that regular 15" 604Es do instead of the wide edge of later 16" frames and they look to be white.
Did Altec make a 16" frame with the narrow mounting edge?
Here's a 604-8G with the wide mounting edge 16" grey frame:

View attachment 3168152

This is interesting because I just did a Google search for 604-8G and this image came up. I did a double take because that's my carpet so this is actually my old 604s at my old house in Vancouver.

I've never put the tape to them, but they look wider than the 15" Utahs and they sit into routed indents so I had always assumed them to be 16". (Maybe the grooves are cut within the routed indents?) Some could certainly have been white, especially early ones. Altec made their guitar (418B) and bass (421B) speakers in white. I've never looked inside.

Altec 604E2 Super Duplex
HF horn: 90h40v
X-over: 1500 Hz
Power: 35 watts, 50 peak
Impedance: "8 to 16 ohms" was really nominally 16 ohms
Weight: 34 lb.
Magnet: Alnico V magnets
Response: 20Hz - 22kHz
Free Air Resonance: 25Hz
Frame: cast frame grey paint
Cone: paper cone with an "accordian edge" cloth surround
comment: later 604E called 604E2 had the later 16" cast basket and tangerine phase plug

 

[Feral Kid]

Mount them on the back of the baffle. If you see other cabs with 604s mounted the front of the baffle , they either have newer style 16" frames or the people have cut notches in the baffle to allow the frame to sit flush.
I had a pair of 604Es and built cabs with a removable baffle section so I could try both front and rear mounting. I couldn't tell the difference and the rear mount gives you more frame contact area than the front mount does. The cone has a very small amount of movement so even if you make the opening 13 3/4" instead of the recommended 14 1/8" you will not have any issue at all and you have enough space to use tee nuts or through bolts if you want. It's a good idea to slightly bevel the opening so you don't cause anyone to ridicule your choices.
I like that the Stonehenge fits in a room more easily than a 620 style cabinet but the 620 provides a nicer midrange due the wider baffle. You could also search at DIY Audio for a variety of MLTL cabinets that get more and better bass and have a similar profile to the Stonehenge.

Thank you for the great advice. Originally I was going to notch the baffle but it was looking too close to the mounting holes for my taste. I did my best to choose a good cabinet. I tried to find a drawing of Hiraga 604-Alnico 41" X 20.1 X 18.1, but could not locate one. I did find a drawing that was similar in dimensions so I went for it. I have never listen to or built speaker cabinets like this. Ultimately I plan to use a SET (300b) amp. The 3/4 Birch is cut up except for the hole for the drivers. I did think about beveling the hole for the drivers, the front baffle is 1-1/2" thick. Tee Nuts may be the ticket. See attached the drawings.

 

[kyle]

Thank you for the great advice. Originally I was going to notch the baffle but it was looking too close to the mounting holes for my taste. I did my best to choose a good cabinet. I tried to find a drawing of Hiraga 604-Alnico 41" X 20.1 X 18.1, but could not locate one. I did find a drawing that was similar in dimensions so I went for it. I have never listen to or built speaker cabinets like this. Ultimately I plan to use a SET (300b) amp. The 3/4 Birch is cut up except for the hole for the drivers. I did think about beveling the hole for the drivers, the front baffle is 1-1/2" thick. Tee Nuts may be the ticket. See attached the drawings.

Note that the plans are for a 16" frame which mounts on the front of the baffle.

Thank you for the great advice. Originally I was going to notch the baffle but it was looking too close to the mounting holes for my taste. I did my best to choose a good cabinet. I tried to find a drawing of Hiraga 604-Alnico 41" X 20.1 X 18.1, but could not locate one. I did find a drawing that was similar in dimensions so I went for it. I have never listen to or built speaker cabinets like this. Ultimately I plan to use a SET (300b) amp. The 3/4 Birch is cut up except for the hole for the drivers. I did think about beveling the hole for the drivers, the front baffle is 1-1/2" thick. Tee Nuts may be the ticket. See attached the drawings.

I will emphasize, don't cut the front of your baffle to make your drivers fit. It's not worth it and there is not enough material left to mount the drivers properly. If you absolutely need to front mount, use JBL type clips to hold the driver in and notch the baffle to fit the ribs. This is a crap application though and I would not recommend it.
Do the right thing and use the drivers as intended by the designers, mount them on the back of the baffle and make the opening 13 3/4" so you can use decent fasteners. Look at DIY Audio for "Altec 604 MLTL" There is a guy that posts as GM (Greg Montfort) who know more about Altec cabinets than anyone else. He's been designing them for decades and if you ask politely, he will provide you with proven designs and help throughout the process. It's worth the time to get the best out of a great and classic driver. You have a very desirable speaker and in the right cabinet with the right crossover it will out perform most modern speakers under $5000 today. If done with an eye to doing it right you will never upgrade.

 

[Feral Kid]

Greg Montfort

I really don't know the proper way to contact Greg Montfot. With due respect I would like to ask Greg for advice about my 604e cabinet build. Thank you Kyle for suggesting mounting them on the back of the baffle and make the opening 13 3/4". I made a 3/4" template from scrap 3/4" ply. Then I marked the mounting holes for precise attachment of the drivers. I will add another 3/4" ply making the front panel 1-1/2" thick and route it to a 45 degree bevel. I will mount the diver and see how it turns out. Any comments are greatly appreciated.

 

[kyle]

I really don't know the proper way to contact Greg Montfot. With due respect I would like to ask Greg for advice about my 604e cabinet build. Thank you Kyle for suggesting mounting them on the back of the baffle and make the opening 13 3/4". I made a 3/4" template from scrap 3/4" ply. Then I marked the mounting holes for precise attachment of the drivers. I will add another 3/4" ply making the front panel 1-1/2" thick and route it to a 45 degree bevel. I will mount the diver and see how it turns out. Any comments are greatly appreciated.

Join diyAudio and look at the bottom of the first page of this thread. GM is Greg Montfort. Post a question about what you want to do and he'll probably answer or you can PM him there. https://www.diyaudio.com/community/threads/great-plains-audio-604.319823/#post-5983828