Orelo/Orelino with Horns (Orelo/Orelino)

by TonyB, Toronto, Canada, Wednesday, March 05, 2014, 18:57 (3697 days ago)

I am looking for “something” that will cover frequency band below approximately 350Hz.
The range above 350Hz will be covered with compression drivers with a 200Hz horn,
a 600Hz horn and a tweeter. The crossovers will be approximately 350Hz, 1200Hz and
5000Hz. That “something” has to be compatible with horns sound wise. The three
horns will use low power SET amplifier. I am willing to use some “powerful” solid
state amplifier below 350Hz. Since the range below 350Hz covers voice, the amplifier
has to be good sounding. I am thinking of a 30W Hiraga amplifier. My room is
20’ W x 40’ L = 6m W x 12m L, opened to the rest of the house through a large
stairway. More power is needed here compared to a smaller room. The speakers cannot
be placed on the front wall or front corners.

I want all horns/drivers to be time aligned without using DSP time delay. My
original thought for the range below 350Hz was to use either Onken bass reflex
enclosure or a 80Hz – 100Hz horn with a cone driver plus a sealed bass enclosure or
a bass folded sub horn.

The other option is to use an open baffle with horn type wings. Western Electric
did it long time ago. First I saw GIP baffles with WE designs. Then I came across
Wolf von Langa design and finally Bert’s.

So I started looking at Orelo/Orelino.

Orelo would be a good candidate considering I have 8 Altec 515B 15” drivers sitting
at home collecting dust. My ceiling is only 2.06m. I am little short of the 2.1m
full Orelo height but based on previous Bert’s posts, it should not be a problem to
make a slightly shorter 2.0m tall version. However, the biggest problem with Orelo
is how to integrate it with 3 time aligned horns. I would have to make some (ugly)
structure holding the horns in front of Orelo. That would cause time misalignment
corresponding to at least 25cm difference between Orelo and the compression drivers.
I am not thrilled about such time misalignment considering the crossover would be at
350Hz, in the human voice range.

Orelino may therefore be a better solution with the horns placed above it. Nothing
is for free. Orelino is smaller. A smaller baffle causes the baffle bass roll off at
a higher frequency. That can be compensated for with an EQ but the drivers will have
larger excursion at lower frequencies, causing higher distortion. I am not sure if
Orelino dimensions were published. I would expect that Orelino’s ratio of depth to
width is higher than that of Orelo. That will give a narrower and longer throat
causing lower frequency “horn” cut off. In addition, Orelino may have
harder time in a large room like mine.

Any suggestions for my low end?