I recently bought a pair of Altec 9440A amps that I really didn't know much about and researching information on these, of course you always come across info on the VOT speakers. Perusing the internet the other day, someone was advertising a pair of A7-500 that while not cheap, seemed cheap to me for a pair of A7-500's - only going by too fast research on the internet, and having caught a little bit of Altec fever from the research I was doing on the amps, I did something I've never really done before and being totally ignorant about what I was buying, decided I might be eating Ramen soup for the rest of the month and purchased speakers that I didn't even know what drivers were inside them. I don't know if it's true or not but I was told these were bought new in I'm thinking they said 1967, had been passed down to the son who was now selling them - not too wise buying speakers with only that info but I had the fever.
Getting them home, I'm obviously as curious as can be what the heck I have and have been trying to remove the back for far too long and it appears I'm going to have to go get a dremel cutting disk and cut them off. I've been trying to work a knife around them, cutting off decades of paint but it's not working and any attempt to pry on them will result in one torn up back panel. I'd guess it will need replaced anyway but for now I'd prefer not to tear it all up.
Until I can get it off, curiosity is killing me - what exactly did I buy ? Did I really over pay or did I get the bargain I'm hoping I did. Just starting my research I have a lot to learn and it seems as tho no matter what I have I've bought a project, it seems the real question is how much of a project did I buy and will the end results be worth it.
One thing I noticed with the covers off was the speakers were seemingly set up different.
One speaker has what seems to be just the N-800-C dividing network while the other speaker has the N-800-C PLUS a N-1600-D dividing network. Sound wise they seem to sound the same to me tho I haven't yet been critically listening.
Hoping to get lucky and get the model numbers, I stuck my arm in the cabinet and took some pics. I was wondering if anyone could confirm what I think I have or tell me what they think they are.
Also, when taking the pic of the LF driver, I was taking the pic of the one with the additional divider network and the pics showed 2 wires bare, not connected to anything. 1st thing I need to know is there a chance I could damage the dividing network if those wires touch the speaker - if they aren't already ?
Any reason why one would have the extra N-1600-D ?
As for the drivers, comparing pictures with what I took, I'm guessing the LF driver is the 803B and the HF driver is one of the variations of the 802 - would I be correct or am I not even close ?EDIT - these were advertised as A7-500's so the HF driver maybe the 806A ? These are possibly the A7 Magnificent ?
If so, ignorant as I am, are these good drivers to be working with ?
I apologize for my ignorance here, it's just I've never bought anything without knowing what I'm buying before and I'm thinking I got at least an ok deal, don't really want to say what I paid for them right now, let's just say it wasn't a goodwill bargain find.
Bad intro post , just know I'll be pouring over every even semi-relevant thread here shortly though I apologize in advance but will probably end up having a bunch of questions.
Any info u can give me on these is sincerely appreciated.
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Last edited by donberry; February 6th, 2018 at 09:43 AM.
HF drivers appear to be 802D, although they could possibly be late 802C. They'll have a foilcal that will solve any mystery.
Nice green complimentary 811B horns(so not A7-500's).
Woofers are either 803B or 416A, again, the foilcal on the magnet cover will solve any mystery.
Seems they were early 1960's A7's that someone built grills for and inverted. A really nice group of components with the N800-C's. Given the inclusion of correct horn brackets, and interior gray overspray, i feel they are factory cabinets/A7 systems. But, that is just my .02.............
How the N-1600 network got into the mix will likely remain a mystery. My advice would be to get the N-800C's properly sorted out and get the N1600 outta there. Save that for your next duplex project.
I'd eat Ramen for a week for em, i'm not sure about a month.
Last edited by bowtie427ss; February 6th, 2018 at 11:09 AM.
Not all vegetables make good leaders.
Hello again, Don -
I replied to your similar post over on AK, and I think that your pictures may confirm my guesses there. I'm thinking that at some time somebody may have installed a 604 coaxial in one of your cabinets in order to use the 604's HF driver to extend the top end, effectively creating a three way configuration with the 802/811B as the midrange. Maybe they decided against the experiment? Why they would have left the N1600 in the cab is a mystery.
Bowtie is one of the premier "Altec Gurus" that I mentioned in my AK post. One of our "final authorities" when it comes to Altec.
So I'll address this question to him: do you think that the 802 drivers are retrofits, or were the A7s ever offered with the 802s? All the reference catalogs I could find from 1960s show them equipped with either 804 or 806 drivers.
Either way, Don, I think you've rung the bell on this purchase. If you end up liking the A7s after you've performed the modifications typically made when these are used in the home (such as adjusting the vent size for better LF performance, bracing the cabinet horn mouth, and passively equalizing the horn response, etc.), you'll have a system that will provide many more years of musical enjoyment.
I'm anxiously awaiting seeing your progress.
GeeDeeEmm
A7's were definitely offered with 802's.
I pretty much second Bowtie's info.
Cone number makes me think 803B
Your neighbors called. They like your music.
Gotta go back before the Jimmy Ling era when the corner cutting started.All the reference catalogs I could find from 1960s show them equipped with either 804 or 806 drivers.
Check the 1954 catalog below for the A7 description. Hint, the pic and description are on opposite pages. IMO, 804/806 never had any business being in an A7 system.
Altec
Here's a 1959 catalog page with the A7 components listed:
http://www.hifilit.com/Altec/1959-i.jpg
Last edited by bowtie427ss; February 7th, 2018 at 08:52 AM.
Not all vegetables make good leaders.
finally got into it. they put a thin piece of veneer over the panel and some of the screws were beneath the veneer.
The LF driver is the 803B and the HF driver is the 802D - not sure what to make of the readings on them tho. Supposedly 16 ohm drivers, the 803B was reading around 10 ohms and the 802D was reading about 7.7 - 7.8
Cause for concern ?
Bowtie427ss nailed it of course and it appears to be the 1959 A7 flipped over and modified a tad by enlarging the opening on what should be the bottom but is now the top- basically they did away with the board.
I'd assume the altec engineers knew what they were doing, should I flip them back over as they were made ?
I'm trying to over simplify this. I may have gone too far, so if GM could chime in would appreciate it.
Be aware of the difference between DC resistance and impedance. A meter will measure DC resistance, since it works on DC. That is the measure of resistance to power flow at DC voltage-which is zero cycles per second. Hertz if you prefer, I'm old.
Audio is not zero cycles per second. It goes back and forth, just like a cone goes in and out. The more times back and forth, the higher the pitch. The "resistance" to power flow will depend on the frequency, and mechanical components of the speaker. So it's called "impedance". Resistance is ALWAYS lower than impedance.
Typically a 16 ohm HF driver will measure 10-12 ohms on a DC meter.
Woofers OTOH have more mechanical "inertia". Besides the electrical resistance to power flow the mechanicals will enter more into the equation. That means a larger variation between resistance and impedance.
Anyway, impedance in the old days was spec'ed at a certain frequency. The speaker would be said to be 8 ohms at that frequency. Or 16. Or...ad infinitum.
These days we are more concerned with impedance at crossover point. We need to know it in order to select crossover components to match. An 8 ohm woofer often is not 8 ohms at the crossover point, so if you just plug in 8 ohms, the crossover may be off.
Woofers vary in resistance more than HF drivers. A speaker with a very light cone and little mechanical resistance to movement will generally have higher DC resistance, since it's impedance isn't going to go up as much. And vice versa.
So 8-10 ohms on a woofer is not catastrophic. it will likely be higher, say 12-13 at crossover. Which is why custom crossovers often are better than "textbook" designs, where we actually measure the components. A "textbook crossover" would just assume 16.
Last edited by Old Guy; February 10th, 2018 at 10:12 AM.
Your neighbors called. They like your music.
Audio_by_Goodwill
Michigan, USA
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