Is it possible to cover the whole spectrum, high SPL, low distortion with a 2-way?

AFAIK, none exists for the large format drivers. ;) I mean it was designed to load an 18 cell, 300 Hz horn, so talk about under stressed in a typical HIFI/HT app!

Right, originally designed for the 500 Hz/511 AFAIK and later used on all 800 series, duplex as amp power dramatically increased in the '70s.

GM
 
This kinda sheds some light but doesn't suggest yes or no about the lobing. Lobing on the vertical plane might not be a concern for some, and lobing on the horizontal plane is always more of an issue....

Lobing exists, you don't want it, then drivers need to be < 1/3 WL of the highest frequency to be reproduced for us not to hear it in our acute hearing BW.

Your eyes, ears are horizontally opposed, so vertically oriented sights, sounds have a narrow focus, hence not a lot of spacial information to work with; horizontally though, 'smearing' due to lobing, comb filtering is an increasing problem above the ~800 Hz head transfer function [HTRF].

Anyway, this is [one of] Dr. Geddes's fields of endeavor, so looking forward to any thoughts/corrections/whatever.

All I really know for sure is that this Altec 9844 studio monitor and its consumer model is one sweet sounding speaker if not too far off axis: altec 9844 - Google Search

Ditto this '50s era Altec 830A Laguna dual 15"/500 Hz corner system: Altec 830A Laguna - Google Search

GM
 
Why not have one 3D printed to exactly suit the horn and driver angles?

One related question to the experts: how is the function of the diffraction slot influenced by making the horn longer with the adapter?

What about significant driver weight?

Altec's 21216 'universal' adapter dates to the original large format driver and just a short [3.125"] conical extension, so primarily just impacts the BW above ~ 5 kHz.

GM
 
Probably to narrow the beam (further) to increase output and reduce phase and other interference issues.
This horn was designed in order to cover the vocal range in stacked setups with BMS 4590 or 4592 coaxial.

Thanks for the information, IMHO high directivity horns are low-fi devices but unavoidable when a high directivity is required on a large frequency range.
 
One related question to the experts: how is the function of the diffraction slot influenced by making the horn longer with the adapter?

This is a very good question.
AFAIK the inner workings of diffraction slots are very hard to desribe mathematically. IOW it's difficult to 'predict' the wavefront inside and after the slot at one particular frequency, let alone across the band.
Read Kolbreks thesis on 'mode matching' to find out. He couldn't really get passed the 'pinched throat' case, which is just one feature of some slotted horns. Modern diffraction slots are developed by use of computational techniques (FEA etc.).

I am looking forward to Dr. Geddes' reply, even though I am perfectly aware he 'doesn't like diffraction slots', to put it mildly.

Diffraction slots have their merits and they can work very well, if implemented with care. Earlier in this thread some examples were cited.

Here's another:
 

Attachments

  • Polars.jpg
    Polars.jpg
    864.9 KB · Views: 306
Last edited: