Enclosure for 416A

[alpha2941]

Hello,

I just received Altec 416A+driver 804A and horn 811B.
Pls advise small and medium enclosure plan for above set,
I don't know quality of sound from 416A between back horn loaded and bass reflex
enclosure.

Thanks,
Worrapoj

[Altec Best]

What size room are you putting them in.I have a pair of 416-8B's in a set of 612C's right now and they sound quite good with a 1005/288 on top.You can just build a sled for the horn/804 not as much bass as my 19's but not as big either.But super efficient. A few watts is all that is needed.

Larger Cabinet = More Bass
Smaller Cabinet = Less Bass

So if your room would allow go with a Larger cabinet. :2thumbsup: this was in an earlier thread and there are many enclosures to chose from.I would recommend a bass reflex and go with the largest cabinets you can.

Now available here:

AN-11: Construction Plans for traditional Altec enclosures:

http://alteclansingunofficial.nlenet...osurePlans.pdf

AN-12: Construction Plans for 8000-series (they use the 3000-series woofers) Altec enclosures:

http://alteclansingunofficial.nlenet...osurePlans.pdf

AN-5: Customizing Altec enclosures:

http://alteclansingunofficial.nlenet...Enclosures.pdf

[alpha2941]

Thank you very much for your recommend.
My living room size 4x8 M. but it's not enough space for larger cabinet, if I prefer to put
horn and woofer inside the cabinet. Pls recommend the type of enclosure for this limitation.

Thanks

[GM]

Greets!

OK, then, tell us what is the largest height, width, depth you can tolerate along with your ear height from the floor when seated at the listening position.

GM

[alpha2941]

Thanks, maximum width & depth space for enclosure approx 28 & 26 inch, height up to
36 inch, ear height from the floor when seated at the listening position approx 30-34 inch
and far from the speaker about 76-85 inch.

Worrapoj

[Altec Best]

Those dimensions are really quite large almost as big as a model 19 39x30x21 HxWxD is what my 19's measure my concern though is the distance you are sitting only 6-7 feet from speaker.Little over 2 meters.With large cabinets/speakers IMO you should be min.8-10 feet or 3 or more meters.

IMHO you would be better off with a 12" speaker that close.Like a 414 In those links I had posted you should be able to find a enclosure that will meet your Dimensions.Just match up the closest to them.I think a 612 or 1233 would work with those dimensions.Are you building or are you looking to buy them.Maybe GM has a better cab?

[alpha2941]

Thanks,

I have pair of 416A+804A+811B+N800E and looking for Altec's plan for building enclosure,
I don't know all our driver suitable with the enclosure Valencia 846A or not?
Model 19 enclosure may be not enough space for my living room.

Regards,
Worrapoj

[GM]

Thanks, maximum width & depth space for enclosure approx 28 & 26 inch, height up to
36 inch.........

You're welcome!

OK, your maximum outside dimensions (o.d.) yields nearly 13 ft^3 internal gross (i.d.) before subtracting out the drivers, horn, etc. (~1 ft^3) assuming 0.75" thick material (preferably Baltic Birch or similar), which a 416A needs every bit of to go down to its Fs with any authority once EQ'd..

There's no detailed Altec drawing for such a cab, but the basics of cab construction are here and the Santiago's basic drawing on page 22 is a good place to start for your components, so stretch it out to your 36" H x 28" W x 26" D and add the horn inset which is 9.5" H x 3.25" D with the 811 cutout centered, The woofer cutout is centered within the lower space, so this equates to 9.125" down from the horn inset: 1974 Enclosure Manual

I recommend you make the front baffle in two removable pieces, one 18.25" H to hold the woofer and another below it so you can experiment with different vent tunings to get the best blend to your room as well as being able to easily rotate your drivers without having to remove them from the baffle.

Minimum vent area (Av) = ~25.13"^2, so starting with 4" and experimenting back to just a baffle thickness reflex vent should be a wide enough range to find something that sounds good once the horn level is set. Note that they may need to be tuned differently depending on room shape, speaker locations, etc..

That, or tune them both to Fs and tonally balance them by adjusting the horn level and adding series resistance if more flattening is desired. This will probably roll off the highs too much in which case add a capacitor in parallel as required to let the extreme highs through unattenuated.

Note that the vent(s) should be near/at the bottom and the horn recess needs to be damped: http://www.lansingheritage.org/image...iago/page2.jpg

GM

[alpha2941]

Thanks

I will be studied as your recommend, this is my first pair for making enclosure by myself
and don't know more detail about theory and fine tune them.
Many thanks for your info with recommend for me and Altec user.

Worrapoj

[GM]

You're welcome!

Fine tuning is simple enough, either use test gear to measure each speaker's response at the listening position and find the vent length that yields the flattest response; otherwise you just do it as best you can by ear.

GM