another Sachiko build

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Yeah its a 33% version of the real one.
Was considered big at the time, now 40% is the norm in giant scale rc.

I have a pair of 206e's a few years old.

I fired up one incomplete box yesterday, still needs the deflectors.

The sound is excellent, these are the most sensitive speakers I have ever used, the sound jumps out at you.
They project a large full sound source like electrostatics.

Playing the speaker alongside the other blh box I have, I can hardly hear that box. I also have a small sub which appears to be now irrelevent as I am getting more lowend with the Sachiko.

An externally hosted image should be here but it was not working when we last tested it.
 
An externally hosted image should be here but it was not working when we last tested it.


I completed the pair last week.

Unfortunately I found they were a bit too efficient,

I am using a preamp(Welborne Ultrapath) which has an electronic stepped attenuator driving a gainclone.

On the lowest notch it was quite loud, so much so my diy sub couldnt keep up.

So I put in the bsc I had with my previous blh and that toned things down a bit as well as boosted the lowend.

Is it unusual to use BSC's with these large double horns ?

I am happy with the sound quality and the sound projected is quite large and imposing, kinda like some large accoustat 8foot electrostatics I once heard. Luckily I have a fairly large room, I suspect a small room might be different though.
 
Indeed. They need a large room, hate being near boundaries, & you have to be a minimum of 8ft from them for proper LF wavefront integration.

They self-correct for baffle-step loss, so your shelving filter will be reducing levels above whatever frequency it's set at to levels below that of the LF.

One thing that's got me scratching my head a bit -you say they're too efficient. That has the opposite effect to what you describe. The cabinet is a high-gain horn that only works up to just above the mass-corner of the driver & does nothing above that (aside from attenuating the upper treble regions due to the high level of damping imposed on the rear of the cone), so if you're saying the response above it is too hot, that's inherently nothing to do with the cabinet.Possibly your choice of ply isn't helping -I can't see too clearly in the picture, but it doesn't look like the baltic birch they were designed for & is unlikely to be as stiff, so they might have some panel resonance problems.
 
I have them against a wall due to room constraints here,
so I guess this is a big factor right now.

Also its made with regular ply as baltic is unavailable in my country.

I'll try them away from the walls and see the difference that makes.
When I say efficient I meant sensitivity-wise
 
I have them against a wall due to room constraints here,
so I guess this is a big factor right now.

I know the feeling, believe me.

Also its made with regular ply as baltic is unavailable in my country.

You might find it worth doubling the sides then, and this is one of those rare occasions where (good Lord forgive me) MDF would probably be useful.

I'll try them away from the walls and see the difference that makes.

It should help the stereo imaging at the very least if you can get them away from side-walls.

When I say efficient I meant sensitivity-wise [/B]

If it's too much for your existing pre to control properly, you'll probably do OK by using a series resistor sans inductor, although that'll also fool with the balance somewhat. A line-level attenuator might be a better idea, until you can upgrade your preamp.
 
actually the preamp kit was an Xmas upgrade
however it has an adjustment to drop the gain a bit so I need to open it back up and check on that.

The drivers aren't enabled, they get a lot of sunlight and somehow they eventually got discolored, its also a bit humid here in the tropics.
 
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