Clipped and Shorn Posted June 14, 2005 Share Posted June 14, 2005 Its time to put together those two VOT boxes I have out in the other studio (where the Ampex ag440c will be living). I have the components, but I want to know is if it better to mount the Altec Horns on top of the box or fit them into the two open rectangles which are just above (or below depending) the bass horn. If I mount the 511 horns atop the box, then I assume I will have to close up those large rectangular openings but leaving a certain amount open for a port. There is also a small square hole in the back of the cabinet, could that serve as the port? in which case i would completely cover up these large rectanglular openings. If someone has done this or knows about VOT, I just want a basic set up that will work, I am not looking for another research hobby and a whole other forum at this time. C&S Link to comment Share on other sites More sharing options...
Guy Landau Posted June 14, 2005 Share Posted June 14, 2005 Mount the horns on top of the cabinets. The rectangular openings should be left open. Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted June 14, 2005 Author Share Posted June 14, 2005 Is the volume behind the woofer irrelevant with this design, as opposed to a bass reflex design in which the volume of the box is critical? If they are mounted inside do you leave the space open around the horns, that is what it looks like in these photos. Should the back access opening be closed as well? Apparently people do this both ways. What are the advantages of not putting the horn inside like this? What are the advantages of the horn on top? C&S Link to comment Share on other sites More sharing options...
Duke Spinner Posted June 14, 2005 Share Posted June 14, 2005 This design is both Horn Loaded, and Bass Reflex i think the bass horn loading goes down to 130 hz, or so ..then it's all B.R. i would mount the horns in the port ..yes, you leave the rest open i like that Cab Tuning the best ... Link to comment Share on other sites More sharing options...
colterphoto1 Posted June 14, 2005 Share Posted June 14, 2005 I usually see them flipped the other way with port on bottom, horn loaded woofer, then mid/hi horn on top. Yes the port is that whole 6" slot with only 3/4" depth. Michael Link to comment Share on other sites More sharing options...
Guy Landau Posted June 14, 2005 Share Posted June 14, 2005 http://www.lansingheritage.org/images/altec/catalogs/1963-pro/page08.jpg Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted June 14, 2005 Author Share Posted June 14, 2005 Thanks fellas, except now we have a tie. I am thinking it might be easier to change out different drivers on the horn with it on top, and also it gets the woofer higher up. Do these things amount to anything significant? The object is less obtrusive with the horn on the inside (keeps the top of the cabs free for other stuff). Are you saying that it sounds better to you with the horn mounted on the inside of the box. This seems like it changes the "port" opening quite a bit, and also the horn takes up some volume on the inside thus changing the bass reflex aspect of the chamber. I am up in the air here. C&S Link to comment Share on other sites More sharing options...
colterphoto1 Posted June 14, 2005 Share Posted June 14, 2005 yeah, like that, that's what I'm talking about! That hole in the back might have been for another network. I think Altec had some cabinet-mount types as well as the surface mount in your photo. Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted June 14, 2005 Author Share Posted June 14, 2005 That port is bigger than 6". OK, guess I will put the 511 horns on top, woofer horn in the upper position with that enormous port left open on the bottom. I will seal up the hole in back because I do not need to mount a network since I perfer bi-amping. Is there anything else that is suppose to be going on inside these boxes? I got them as a used bargain. I think I see a bit of insulation left in there. Guess I will have to mount the mid horn hardware into the top of the box. Also the boxes need a paint job. Anything critical as far as paint on those curves horn baffles for the woofer? With the exterior mounting I can do comparisons more easily, eg. between an 811 horn and a 511 horn, and also compare drivers more easily. C&S C&S Link to comment Share on other sites More sharing options...
dragonfyr Posted June 14, 2005 Share Posted June 14, 2005 In all the years of playing with A-7s, I never actually saw the horns mounted in the port. But the Altec Assembly Instructions clearly show this as a secondary option! Strange! But it would certainly change the cabinet loading. My guess is that it was simply offered as a practical option. But the Baby A7s did employ a 'Cornwall style' reflex loading with all the pieces and parts contained in a smaller formatted cabinet... A7assemblyInstr.pdf Link to comment Share on other sites More sharing options...
Duke Spinner Posted June 14, 2005 Share Posted June 14, 2005 like i said ... i prefer the Cab Tuning w/ the port on top, and the horn in it .. less Boomy, the A-7 doesn't have the best low bass definition you really need to go to the "Altec Users" forum .. lotsa posts on A-7 Link to comment Share on other sites More sharing options...
colterphoto1 Posted June 14, 2005 Share Posted June 14, 2005 Dragon, are you referring to the A7-8 with the 811B horn? Paint color preference would be Theatre gray, a kind of flat battleship grey. I think I have an old Altec catalog, will look it up and see if I can get you a paint number. I'd use an oil based enamel if it were me. They look really funky in black for some reason. I think they all came from factory in Theatre gray. Michael Link to comment Share on other sites More sharing options...
dragonfyr Posted June 14, 2005 Share Posted June 14, 2005 Most were the grey, but they were available in a flat black as well. We typically ran the A-7-500's and often with the even larger format multicell horns - the neat thing being that they can have their Q & dispersion pattern modified by blocking the individual cells - up to 1/2 of them. Link to comment Share on other sites More sharing options...
colterphoto1 Posted June 14, 2005 Share Posted June 14, 2005 go here http://forums.klipsch.com/idealbb/files/scottsgarage.jpg Link to comment Share on other sites More sharing options...
djk Posted June 14, 2005 Share Posted June 14, 2005 If you have an 811 horn it must be mounted on top. If you have a 511 horn, invert the box and mount in the port, only the wide board is used. Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted June 14, 2005 Author Share Posted June 14, 2005 Yes, Michael, they are black and they look funky. I like grey. So it is decided, the horns will be on top of cab, and I leave the gaping port wide open and on the bottom. The hole in back will be sealed.They will be grey or whatever close mistint alkyd I have on hand, probably brushed. If that doesn't look cool I will do my usual Pollockesque finish. Bi-amped with tube amps. I will have to decide on the right preamp from vintage on hand. Is insulation needed on the inside for anything? C&S Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted June 14, 2005 Author Share Posted June 14, 2005 ---------------- On 6/14/2005 7:59:49 PM djk wrote: If you have an 811 horn it must be mounted on top. If you have a 511 horn, invert the box and mount in the port, only the wide board is used. ---------------- What is the reasoning here? and what is "the wide board"? I have both a pair of 511a and 811s on hand. Top of cab mount makes comparisons less work, although I have to fab a bracket system, which should be a piece-o'-cake. C&S Link to comment Share on other sites More sharing options...
djk Posted June 15, 2005 Share Posted June 15, 2005 "What is the reasoning here?" For time alinment the 811 has to be too far back to fit inside the box properly, the 511 is the correct depth. "and what is "the wide board"?" The port opening is formed by a narrow board and a wide board. When a 511 is mounted inside the box the correct port area is provided by removing the narrow board. The A7(825) is shipped with the wide board at the bottom for theater use. http://www.lansingheritage.org/images/altec/plans/1968-enclosure/page02.jpg For home use you invert the cabinet and remove the narrow board and then move the wide board to where the narrow board was. http://www.lansingheritage.org/images/altec/plans/1968-enclosure/page05.jpg FG as shown. http://www.lansingheritage.org/images/altec/plans/1968-enclosure/page09.jpg My first 'real' speaker was the A7-500 in cherry (1972), in 1973 I bought a 1953 Klipschorn and let the Altecs go down the road (I did put an Altec 802 on the K5J instead of the SAHF), it already had the EV T35 upgrade. Link to comment Share on other sites More sharing options...
Duke Spinner Posted June 15, 2005 Share Posted June 15, 2005 OOOOh, Dennis ... A7-5 in Cherry ....... ......... ... .... ... i want some ..! Link to comment Share on other sites More sharing options...
CaptnBob Posted June 15, 2005 Share Posted June 15, 2005 In the late sixties, Altec supposedly sold an A-7 painted in "Psychedelic" colors. I've never seen one, but the concept alone boggles the mind. Link to comment Share on other sites More sharing options...
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