Finished horn modelled with MJK's analysis worksheet

[awhite1159]

Just finished horn modelled with MJK's spreadsheet. The internals are similiar to Olsen's dual waveguide horn that starts out as a series of split manifold's which empty into a main horn section. It sounds as modelled (Definitely getting into the 30's) although I have not measured its response yet. Some design goals I had were nearly square mouth (438mm x 434mm), 1220mm H x 536mm D x 470mm W, .85xSd throat, Exp-Hyper flare T=.45. I even found a good deal at lowes for ply that is maple on one side and birch on the other and made the uppersection maple and the mouth birch.

One question I have though and it may be my error is that it seems the T/S parameters really don't effect the analysis in the worksheet. Am I doing something wrong? Iam using the FF225K now but want to try the FE207.

[Scottmoose]

I doubt you're doing anything wrong (although I'd have to see your inputs to be sure). If you want to run a quick check, stuff the Visaton B200 T/S specs. into your model. You'll be much more likely to see a difference with this unit, as both Vas and Q are relatively high. As a general rule, hybrid BLHs are often quite forgiving of moderate driver changes (though they'll usually work better with the unit they've been optimised for).

[awhite1159]

Thanks Scott. I'll give that a try. Since I had the FE207 handy and it was an easy replace, I figured why not. The differences are subtle but unless I am imagining things it sounds better than the FF225k as far as clarity and low end.

[freddi]

hi Andy - this one looks good - FWIW AJ-Horn would not show much difference betweeh 206 & 207

if 207 has more highs than 225 then that could make the bass sound better.

I'd like to know how BLH like this play dynamically vs my Karlson w. 15" coax or 18" + slotted - tube - I've got Super 10 in 70l reflex - nice nuff in 8x10 room but dynamically restricted even then compared to what I"ve used. Are FR BLh what I "need"?

Freddy

ps - no "low bass" with K15 or same size w. 18" but whats there is pretty good and low cone excursion is a good thing -- 200W input peak on odaiko sounds ok

[awhite1159]

Freddy,

The room I have it in now is about 20ft x 20ft with a 14ft ceiling. (Garage). I always hear horns need alot of room so 8x10... I don't know.

Here's how this modeled in MJK's worksheet. You should get alot of 'cabin effect' in that room.

[freddi]

assuming half-space that looks pretty close to RCA Fan's 186 liter air-volume BLH sim.

my other rooms are somewhat larger - one ran K-horns and could run the old Edgarhorn 100 - also have FH1 and Sentry IV junkers but they're only midbass like La Scala

how powerful sound does this type get vs 15" coax in bass reflex? I need a rough reference for dynamics

Freddy

[Scottmoose]

Nice response.

You'll probably get better LF clarity as the 207 has 5 times the liner excursion of the 225, so you'll be getting less distortion down there. That said, it proves the 225 goes past Xmax quite gracefully, as you imply they still sounded pretty good.

[awhite1159]

Thanks Scott. I think when I get home from work I am going to stick a FE208Z from one of my Fostex enclosures in it and see how it sounds. If it sounds good, I'm replacing my Fostex horns in my Family Room with these (After I build the second one.) Its a fairly easy build and uses a little less than two 4x8 sheets of ply.

Here's the split section prior to the convergence into the main horn body. I opened up the throat to .85xSd. One strange thing I also notice with this horn vs. my first horn is that the other horn seemed to suck the life out of the speaker. It lost alot of its midrange. Now these sound alive.

[awhite1159]

I know this might sound like a woodworking question but I am looking for advice. This horn looked really nice when it was white maple with the birch mouth. Last night I put a black ebony stain on the white maple portion and I don't like it. Is there any way to get the stain off? I know if I sand too much it will probably remove the finish since it is ply. Or am I stuck with it?

[bobtrancho]

I know this might sound like a woodworking question but I am looking for advice. This horn looked really nice when it was white maple with the birch mouth. Last night I put a black ebony stain on the white maple portion and I don't like it. Is there any way to get the stain off? I know if I sand too much it will probably remove the finish since it is ply. Or am I stuck with it?

If the maple is ply then you are probably stuck with it as the stain most assuredly penetrated the first ply layer. If it's solid maple you might be able to sand it out but you'll have to take off a fair amount of wood to get down to a consistent, clean level.