My A7-500s. A journey

**Altec Best** · November 24th, 2009, 03:51 AM

Hi Mike,

Well that didn't take to long I can see a half smile almost there

good deal....

**Panomaniac** · November 24th, 2009, 10:38 AM

You're right John.

Just a little work and they already sound much better. In many ways better than my home made Big Ugly Speakers.

The right crossover, the right horn and the right port take them a long way. Very promising for the future improvements.

**-ec1288** · November 24th, 2009, 11:41 AM

One of my DIY audio projects - Altec Lansing A5
Configurations are as follows:-
Cabinet - 825
Woofer - 515B
Horn - 1005B
Driver - 288C
Crossover - DIY

For details, go to link showed in my signature.

**Old Guy** · November 24th, 2009, 11:53 AM

You could probably Fleabay the 511's and replace them for not a lot of cash difference...

Ditto the Symbiotik frams...

I had a friend who poured the horn curve on the A7 full of plaster...I generally just used high density urethane foam...you can get small amounts mix and pour, or use a bunch of the cans...

**Panomaniac** · November 24th, 2009, 03:16 PM

Not sure I want to dump the 511s, yet. Am willing to work with them, they may have hidden talents. But I guess I don't really "need" 3 sets of horns - 811-511-803 and drivers 802-806-291 =)
Gotta find what works best for me.

By foam, do you mean the light brown stuff they use in boats? Does it stick well to the walls? It's heavier than the isolation foam in cans, yeah?

ec188 - nice work! Those cabs are beautiful. The wood is so thick, it makes the boxes look smaller. Crickey, those must be heavy. Nice work bracing the horn flares. I want to do something similar. Inspiring work, thanks.

**Old Guy** · November 24th, 2009, 03:48 PM

Yes it's used for flotation, house insulation, and tons of things.

Comes in different densities. There is even tooling foam for making fiberglass molds, it can be machined.

I suggest one of the heavier densities...

**Panomaniac** · November 25th, 2009, 12:31 PM

Well I did try the 806a driver (aluminum diaphragm) on the 511 horn in place of the 802 with symbiotic 'fram.

Much better. More balanced, less shouty, better overall. I still think the 811/806 combo sounds better, but the 511/806 combo is not bad. Works OK down to 500Hz, but seems a bit cleaner at ~700Hz. So better frams in the 802 ought to sound nice.
FWIW, the 802 with no horn makes a nice tweeter.

Also played with the 803B/291 horn/driver combo in top of the A7 - which would make it an A5. I like it! Looking forward to hearing what the aluminum 'fams will do in the 291. Will change it into a 288 and should sound a lot better. If there is as much improvement as in the difference between my 802 & 806, I'll be a happy camper. Many say that the symbiotic 'frams don't sound great. Now I've heard it for myself.

Also did some EQ work just for fun. The 803B/291 combo is far from flat, but I knew that. The big surprise was that the bass cabinet with the smaller port is almost flat. It's the flattest response I've yet gotten at the listening position. Flattest of any speaker I've had in the room. Just needed to pull down about 2dB at 60Hz. No big deal.
Very happy with that.

**gearfreak** · November 25th, 2009, 04:46 PM

Beware (my) good-intentioned rambling to follow. Sorry to stray OT.
Caveat to all suggestions being 'of course you may have already tried it' :-)

Originally Posted by Leland

...a 515-16G and an old 288B Driver with an 805 horn. N-500-C Crossover.
...but just not as refined as the La Scala for my uses.

I found the Plywood 828/825 (whichever they were) cabs with the 416-8A to have a better/wider FR than the La Scalas.
You might wish to make sure that you are comparing them @ the same location in the room (swapping). Corner placement certainly came into play with mine.

Interesting that 'more bass' was attributed to the la scala, not generally known for it's (quantity of) bass reproduction. (unless perhaps turned around to face the corner... which was also kind of neat!) Mine however were industrial, so had a slightly different (iirc) K43 model woofer. Some have said the K33 has more bass in the LS, but that was/is highly contested.

IMO, the LS's folded horn seemed more accurate for (some) lower frequencies compared to the smoother BW of the 416/BR Altec. Whether the altec is horn on floor or port on floor may also come into play, given the size differences involved.

You might investigate whether the 16g is suitable for the N-500-C, or whether it should be an 8ohm woofer. That might be affecting things.

Mine were 416-8A's w/N-500-C's, though rather than recapping, I bi/tri/amped and found this combo most pleasing:

416-8A -> ~500hz (828/825 port = ~80 in2)
808-8A (old, symbiotik afaik) -> ~6000hz (511b)
902-16A (gpa, aluminum) -> the rest (511b)

I liked the 808-8a for MR.
Sounded more natural/compliant to me than the 902's there.
Maybe it was the alnico though.

Alas, did not get to the point of setting up a passive between the 808 and 902... which I think would've been the best scenario for me at the time (using one amp for MF and HF).

*Since you like it - your LS bass section with the Altec multicell on top might be the best of both worlds.

IIRC the K-55/K-400 MR combo crosses to the LS's FH @ 400hz.

If 'daring', you could try to keep them 3-way and just insert the Altec horn into in the klipsch network in lieu of the K55, but impedance differences (K-55=16ohm) may make that less than ideal (?). You'll want to run it at lower levels and/or read up on opinions about danger to running the Altec below 500hz.

**Panomaniac** · November 25th, 2009, 06:35 PM

Gear freak, thanks for the good info. Looks like you tried a lot of stuff.

As Ron said earlier in the thread, I'll get there. =)

Also rereading Leland's post. What you have are A5, because of the multicell horns. I would love to compare your 805 horns to my 803s. I suspect the 805 will be better. The length of the 300Hz horn rolls off the highs a good bit. With my 291s they roll off second order at about 5K. Not what you would call "extended." All aluminum 'frams (288) should help, but I doubt they'll go very high on that horn.

If I could recover on the low end and really cross at 300Hz, I'd be happy. But the 291 just does not play that low. Neither do my Radian drivers. 500 is about it. So maybe the 500Hz horns are popular for a reason.

Getting the bass cabinet right will help the bass, for sure. Just tuning the port makes a big difference. Damping and bracing will be a big help, too.

----

At the moment, things are sounding rather nice. Here is the system as it stands today.

Source: HP laptop. CD, Flac or MP3 files. ASIO drivers (no resample, no K-mixer) -> USB
M-Audio Duo USB: -> SPDIF
SPDIF to AES transformer - 75:100 -> CAT5 cable
Behringer DEQ2496 Digital room EQ and touch up. -> AES out
Behringer DCX2496 Digital crossover. AES in. 3rd order at 500Hz. Delay for woofer, mid dip for horn. Analog out via custom transformers.
Highs & mids: Virtue Audio TWO class-D amp. 24V battery supply. 291/803B combo 500Hz-5Khz. Selenium 1" horn 5K up. (passive off same amp)
Lows: IcePower 65W class-D amp. Altec 416-8A in 825/828 cab.

Getting there.

**Altec Best** · November 25th, 2009, 06:52 PM

Originally Posted by Panomaniac

If I could recover on the low end and really cross at 300Hz, I'd be happy. But the 291 just does not play that low.

Hi Mike, From research I did the only Altec driver of the large format capable of going that low is the 288C maybe something to keep in mind when using the 803's I'll try and find that info for you.