Horn/TL combo

Official Court Jester
Joined 2003
Paid Member
sorry buzz for not supporting your latest buzzing in personal e-mails

ya know that local greedy boyz put me in centrifugal machine , so I'm sorta dizzy of Spice and all these new things to me :rofl:

make it or leave it and put cosmetical things aside

MJK's sheets are Mana from Heaven , and I'll not dispute their results .......

ok - just joking - will check tonight what's going with extended wide of cab , but I'm not expecting anything good

who knows - maybe I'll be surprised ;)

btw. - that's some funny Lowther :rofl:
 
I look forward to what your 414s spec as the range I have varies from as little as ~2 ft^3 to almost 8 ft^3/driver, though if driven with a ~matching impedance, the small cabs would increase to a similar size for a T/S max flat alignment.

IME with a mono DIY version of the 820 VOT using inexpensive drivers, horn and employing flipped, compression loaded corner 210s for decades, I can't recommend any parallel wall horns for HIFI unless the XO point is well below its eigenmodes BW and even then there's a slightly 'pinched' character to the critical mids due to throat distortion that over time negated some of the 'thrill' for me that such horns can generate.

Still, having had such designs for 4+ decades, I was initially bummed out at being forced into ‘only’ having my old subs you saw until I listened to them with the ~stock 511/802/500 Hz XO, immediately noticing how much more open they sounded; so for me, unless only flea power is available, these old PA expo horns are not an option for HIFI or high SQ HT apps.

With the advent of higher power/lower output impedance, Altec got it right with the circa ’59 832 corner cab, it just took a financial disaster for me to learn it. Once again proving that those who don’t learn from history are doomed to repeat it.

When Rod Stewart commissioned Altec to build him some monitors in the ‘70s, they chose the 832’s layout + super tweeters in a by then unfashionably large cab: Google

Also, as Ed implied, the acoustic center of an 817 or flipped 210 or just about any vertically oriented dual woofer/horn app is the excessively long acoustic ctc spacing, so in a small room and/or ~near-field app there will be audible vertical scaling of music, especially piano and singing where there’s a low male vocal. This can be alleviated somewhat by using electronics to ‘tilt’ the horn’s response to overlap at the LP, but like focusing an array, it affects other aspects of overall performance.

All that said, we all hear the same, yet not so much, so some folks will be ambivalent WRT any audible difference in an A-B comparison, hence I leave it to the reader to decide if they want to gamble with such horn speaker designs.

If only large horns will do, then at least slant one baffle like an 825/828 and preferably both.

GM
Hi GM and all,

I rebound on that topic and those affirmation precisely, since I am in the planning of a new speaker system for my home in the next year.

I raved about the Altec 828 but my room is too small to accomodated them (11' x 14' and 8' minimum of heigh, inclined ceiling). One day, I will do some change in my house and have more space (perhaps double it). So I check for corner speaker that I will put in the corners of this room. The Altec 821 (cabinet of the 820) seems to be a good compromise. But is it so ? I planned to put 2 pairs of 515B in it. Is it a good idea ? What is the response of this system in a corner ?

Why the 828? The high efficiency of the system and the quality of the high-bass and low midrange apeal to me.

Of course, I looked for other corner enclosures : Jensen Ultraflex, Altec 830 and 832 and some folded horn enclosure that could be fair compromise.

I also have a pair of Altec 420A reconed in 416-8A that could be a better compromise in reflex enclosure.

So any advise or suggestion?

Thank you,

Regard,
 
Greets!

The 820 was designed for the 803 BR spec'd woofer same as the 800 series whereas the 515B is a compression horn driver, ergo bass will be lacking same as the A5 Vs A7 series.

When you say 'two pairs in the cab', do you mean a pair in two cabs or four in each cab?

515B specs have varied somewhat over time, especially re-cones, so strongly recommend measuring them for matching purposes, cab design.

Ditto the re-coned 420s.
 
Greets!

The 820 was designed for the 803 BR spec'd woofer same as the 800 series whereas the 515B is a compression horn driver, ergo bass will be lacking same as the A5 Vs A7 series.

When you say 'two pairs in the cab', do you mean a pair in two cabs or four in each cab?

515B specs have varied somewhat over time, especially re-cones, so strongly recommend measuring them for matching purposes, cab design.

Ditto the re-coned 420s.
Hi GM,

You are right that the 803 driver was designed to fit in the 800 commercial system. I see the Iconic 820A/C has a kind of consumer version, eventually replaced by the Laguna 830A (corner reflex enclosure).

The 820 is a corner cabinet. In a corner of the wall, did the corner wall act like the wings on a 810/825/828 and elevated the bass like it was indicated in La Voice of the Theater Chez Nous article by John Stronczer?

What I mean is a pair per cabinet. I measured the impedance with a Fluke 77IV multimeter:
  • The Altec 515B have the original 21184-3 cone, and measure : 11.1, 11.8, 12.1 and 12.4 ohms. I bought them from a guy who used them in Onken 360 and Altec 612C. Apparently they came from a church.
  • The Altec 420A reconed measured 5.4 and 5.5 ohms. I commissioned the recone. The original woofer came from Altec Santana MKI and were functionnal.