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In the Forum: Horn-Loaded Speakers
In the Thread: 45Hz Bass Horn
Post Subject: Portable Bass HornPosted by jessie.dazzle on: 5/19/2008

Romy's quotes in blue :

"...Discussing the Jessie project we multiple times mention the idea of the large midbass horn hanging above MF section... The rational was to have it positionally contra-react the output of the upperbass horn... But do we automatically assume that the hanged horn would be a flimsy horn?..."

Well... Apart from really slowing progress on this project, the move to a new "house" means that for as long as I stay in this place (???), I too will be placing the bass horns (45 Hz) down at floor level, outboard of the main left and right channels.

"...The midbass horns were positioned outside the MF channels, time aligned with mouths extended far into listening position.  It was running 50Hz to 800Hz...How high we can go with midbass horn?..."

I will admit that in the case of the smaller upper bass horns (10" driver into 115 Hz horn) I have recently been letting them run with either a high-ish cutoff, or no cutoff at all, other than that which naturally occurs due to the architecture of the driver/horn combination. This is in the interest of increasing output down low, as a coil tends to choke output way below the cutoff frequency (6dB/octave). I am wondering if the decision to let a 50 Hz horn play all the way up to 800 Hz (see previous post) was not made in order to get enough volume out of the horn further down.

"...but do we automatically assume that the hanged horn would be a flimsy horn?..."

As for construction of the 45 Hz horns, the plan allows for hanging or placing down at floor-level... The horns will not be flimsy... Construction will be as follows : Everything down stream of the driver mounting plane will be from glass fiber laminations. These will be true round-section horns... Not so much for sound, but because I am lazy and want to make the horns from as few segments as possible; the compound curvature involved would be more rigid than single curvature construction for the same mass and number of segments... Anyway, given the process it does not entail much more work. Additional stiffening ribs can be molded into the outer surfaces. There would be eight identical laminations to make (four 90° segments per horn). I absolutely hate working with glass fiber, but given my resources and objectives, it makes the most sense (it will mean checking into a hotel to sleep while the resin cures, as I just can't afford additional brain damage). Horns made this way should not be too heavy to suspend if one day I find the right room... Which brings up another of my objectives, this installation must be mobile; a two-man job at max, and all the pieces must fit into a standard 2m-wide sea container. Rear chambers would be one-piece bolt-on castings made via a process similar to that used in the construction of the smaller horns.

I will soon have no excuses for putting off the construction of these horns, as I have finished everything else; the frames which locate the other horns are finally done (still need to paint them), they were a lot more work than I expected. I swear I will post photos soon.

jd*

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