This week I got a new pair of subs to go with my Oris 150 horns. The Vifa bass-reflex cabinets were very good, but they did not match the Lowthers as I would like them to. Too slow and just not the same "tjakkah!". I've been talking to Bert Doppenberg for months about this and he too was thinking of an alternative to the bass-reflex cabinets. Sick minds think alike, and Bert built a pair of front horn subs using 15" drivers. The design is somewhat similar to the bottom part of a Klipsh LaScala I guess. The speaker is housed in the wedge shaped part and pointed towards the rear. It is then reflected towards the front and exits on both sides. I am using a pair of Altec 421-8H speakers in the cabinets. Nice high efficiency drivers with very low moving mass.
I had a visit from Bert today. He brought his Clio measuring system to see what the new subs would do and to tune them a bit. I had actually only set them up the night before and did not listen to them yet. Bass was screwed up because of the previous filtering (active). After some measurements we changed the filter to get a better response. Some semi-final tuning by ear brought us close to something we could live with, or at least start out with.
The things you don't get to see (me at work).
Meet my new cross-over :)
Besides the Clio, Bert also brought along a pair of super-tweeters to show me. I hooked them up right away, you can't just look at them and keep wondering how they would actually sound :) We filtered them with a 6dB filter at 2uF and also placed a 200 ohm resistor parallel to the tweeter to ease the sound of the tweeter a bit. It doesn't really do much, but just enough to add that needed tsssss to the cymbals etc... I'm keeping them for a while ;)))
After some listening and improvising I came to the conclusion that I would need a separate amp for the tweeters since sensitivity was not a match with the rest of the system. As I want to concentrate on the system I had, I will postpone any experiments with tweeters. I'm pretty satisfied with what the Lowthers produce so far anyway. Maybe in the future.
Finally got hold of a pair of Altec 515C drivers. They will replace the Altec 421-8H speakers that are in the LaScala right now. The 515 has a lower Qts (0.25) and fs (25Hz) which makes them best suited for horn loading. I might use the 421's in a Grand Onken experiment,
I tried to hook up some tweeters here; nah, maybe in the future.