Frugel-Horn Mk3 Builds & Build Questions

[planet10]

Originally Posted by kristleifur

Just to clarify - the flat superelliptical baffles wouldn't be worth it, then? Or would they be an improvement over a suprabaffle-less setup, only not as optimal as an SB can be?

It may be. Just be aware that the abrupt edge will bring new issues to the table.

Another thing - What effect if any does the cabinet have on the driver efficiency? Is the system efficiency the same as the driver's, or higher or lower?

The box only affects the band in which it operates. With a horn, the idea is to lift the bottom (where the horn operates) so as to keep up with the mid/top range, as well as eliminate any ** filter which would attenuate the mid/top.

So the efficiency of a rear-loaded horn is typically the rated efficiency as opposed to often a lower efficiency with a more pedestrian box.

dave

[kristleifur]

Thank you for the info, Dave. As a beginner, I'll be putting any baffle ideas pretty low on the list of things to think about.

Regarding the required cuts – As far as I can tell, there cabinet tilt and horn folding require some ~4.8 degree cuts on the ends of some pieces. I know hardly anything about woodworking ... I tried searching for the best method for these cuts, but I came up short. Are there any good resources that show how to do this?

[Cascadie]

By loading the Sketchup model and using the tape measure tool, I'm seeing that the tilt back from vertical is 3" at the top front edge, and the rear edge of the top of the cabinet side is 10.25" back from the vertical axis. I'd hold off cutting until you get that confirmation from the designers. You beat me to this question.

[buzzforb]

Planet 10,
What speaker are you prepping this design for. What kind of distance from the wall should be considered with these. May be willing to be a beta builder.

[chrisb]

Originally Posted by buzzforb

Planet 10,
What speaker are you prepping this design for. What kind of distance from the wall should be considered with these. May be willing to be a beta builder.

Was originally targeted for 3-4" drivers; most notably the Fostex FE126en, Mark Audio Alpair 7, CHR70 (and paper coned sibling the CSSEL70)

As noted in another thread on the subject, I'm not sure how many beta builds have been undertaken or completed ( this is a very quick and easy build compared to the FH-one), or with which drivers.


Dave - perhaps time for a log or builder's gallery on the FH site?


As for distance from wall / corner, that's quite room / driver / amp dependent. With the highly modified Dyna ST70, I personally preferred the FE126En closer to the wall and driven in triode mode, and the Mark Audio drivers further away and with the amp in U/L mode.

of course YMMV

[planet10]

Originally Posted by chrisb

As for distance from wall / corner, that's quite room / driver / amp dependent. With the highly modified Dyna ST70, I personally preferred the FE126En closer to the wall and driven in triode mode, and the Mark Audio drivers further away and with the amp in U/L mode.

Part of that is down to more optimumal damping for the FE126. As i try a bit more damping with the MA drivers i expect they will want to get closer to the wall.

dave

[planet10]

Originally Posted by Cascadie

By loading the Sketchup model and using the tape measure tool, I'm seeing that the tilt back from vertical is 3" at the top front edge, and the rear edge of the top of the cabinet side is 10.25" back from the vertical axis. I'd hold off cutting until you get that confirmation from the designers. You beat me to this question.

5 degree cuts are probably close enuff... careful full scale layout is suggested.

With this question, i will adjust the origin of the side panel on the grid drawings and re-insert them into the beta doc. Some key cartesian points will also be noted, to make layup easier.

dave

[planet10]

Originally Posted by buzzforb

Planet 10,
What speaker are you prepping this design for. What kind of distance from the wall should be considered with these. May be willing to be a beta builder.

We have tried it with, and shown that it works, with a wide range of (4-4.5") drivers. Now up to builders to try their favorites.

I hope to see a broad sweep of drivers implemented.

Versions of FH for larger drivers is premature at this time.

dave

[Ed LaFontaine]

I got a pair of cabinets roughed up today. I'll add stuffing and attach the sides tomorrow. Since I plan to use a supra-baffle, I made the opening for the driver oversize and back chamfered.
In my impatience I selected a sheet of veneered red oak...bad choice...I should have driven the next 25 miles to get baltic birch. The lack of quality in the veneer made the cross cuts a splintery mess. I am now reminded not to try that again for awhile.

[motosapien]

Ed,

Try an 80 tooth blade. They are pricey but I don't think you can get a good cut on ply without a high quality saw blade. Mine is a 10" Freud Diablo from HD that was $60. I'll bet your blade would have splintered up the baltic birch too.