In the backgrond you can see a pair of triangular prisms (in the bottom frame). These are deflectors/stealthWoofers for the FH3. They have a single SDX7 firing towards the wall.
These are the easier to build 90° triangles and about 14 litres. Moving to a more acute triangle — i have drawings with 75° — gives more volume without getting excessively wide, but are harder to build. 75° is IIRC what Ron suggested as optimum for deflector use.
The little cubes on the floor are also SDX7, each with a Foster plate amp (12” cube external, about 14 litre for the SDX7).
I have been (very) slowly and intermittently working on th enext generation… with the revival of the SDX10, a 75° prism for 1 of those looks very doable for the FHXL.
dave
Hi Dave
These deflectors/stealthWoofers what is the function as deflector?
I guess its function is the same as a subwoofer but there must be some meaning in the special shape?
What about crossover?
Thank you for your reply 🙂
David
This concept WAW or FAST isn't that just a fullrange speaker with a woofer?
I found a 30Hz folded Tang Band horn on wp.volvotreter.de - could I use something like that? My thought was to go active two way with a minidsp and as soon as my ACA is build use this for the FH and something with a bit more juice for the subwoofer.
Dont know if this is a good idea?
I am open for all suggestions...
I just want the best possible sound quality 🙂
David
I found a 30Hz folded Tang Band horn on wp.volvotreter.de - could I use something like that? My thought was to go active two way with a minidsp and as soon as my ACA is build use this for the FH and something with a bit more juice for the subwoofer.
Dont know if this is a good idea?
I am open for all suggestions...
I just want the best possible sound quality 🙂
David
This was one of Ron Clarke’s suggestions… it makes sure that the output of the mouth is deflected and not shunted back up the horn. It also acts to better shape the mouth’s horn expansion.
We built the 1st one solid, but after a bit of noodling decided that the volume could also be used as a woofer. Since the woofer fires into the wall it got the stealthWoof moniker.
You can use either the REL-style strategy — letting the mains reach as low as they do, and then just fill in below that, or you can HP the satelites and bring in the woofer a little bit higher.
Room will play a role as to which works best, but the wall-facing woofer means the XO will need to be fairly low.
dave
Yes sort of… 2 woofers and an XO 150-450 Hz or so. With a set of FH3 you really want to treat them as satelittes with subwoofer(s) — ideally at least 2 -- and XO 50-80 Hz.
dave
I have two Velodyne subs I use with my surround sound I think I will experiment with these to find out what works for me 🙂
I have a miniDSP with mike, REW and an excessive supply of amplifiers so no reason to get bored for a few hours 😀
Is it possible to buy the plans for the deflector?
(the 75deg of cause, more difficult=more fun 😎)
The deflectors are really part of the FH3 planset, the issue is finding a woofer for the small one — we used the SDX7 which is NLA. It really isn’t anything special. An isosceles triangular prism the height of the FRugel-Horn. Ron specified something like a 75° triangle (i’d have to dig into the FH1 plans), but we built the one shown at 90° since it was easier to build. The smaller angle yeilds more volume for the same width.
I have decided to see if i can fit an SDX10 into one sized for the FHXL, it could also be used for the FH3.
dave
I have decided to see if i can fit an SDX10 into one sized for the FHXL, it could also be used for the FH3.
dave
Not to derail your thread, but had anyone the chance of comparing FH (either variant) with Dallas II? If yes, how do they compare?
The frugel-horns and DallasII are completely different designs using equally completely different drivers (not even the same sizes), loading type and configuration. So unfortunately, that means that they are apples / oranges to the point that the only realistic conclusion you could draw in a comparison between them is that they're different.
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I have never seen a Dallas II, but i suspect FH3 with FE126En will have much the same voicing, but will do mid/topbetter and not have as much impact low does. Put the ideal (for most people) Alpair 7.3 you lose some efficiency, and maybe some dyanamics but you get a speaker with smoother response, greater DDR and greater intimacy, but as Scott says. very different.
Only the individual listening can say which one best suits their needs — room, room placement, tastes, wife factor, cost.
dave
Only the individual listening can say which one best suits their needs — room, room placement, tastes, wife factor, cost.
dave
I should add that the sound of any of the frugel-horn family can be radically changed by using different drivers in them. One can pick their flavour and expect the horn to get near as much as possible out of them.
dave
dave
I'm looking forward to trying this; have some A7.3s to replace the CHR-70s in FH3s. Might also try the FF125wks I have on hand as well, though perhaps these are better suited for the FHXLs??
Sounds like you need to mod the FH3 for supraBaffles — we now lean toward simple mounting plates — so it is easy to swap drivers. FF125 fits in FH3, FF165 goes in FHXL.
dave
dave
Or as goes the song:
One of these things is not like the other, one of these things is not the same.
One of these things is not like the other, one of these things is not the same.
Luigi - I’d try the A7.3s first - might not need to proceed further.
You can get as fancy as you want with the supra-baffles, but I’d be inclined to make them the same width as the FH3s - would be approx 170mm if using 15mm material, and perhaps 225- 250 tall?
Seal behind with either foam weatherstripping tape or blue-tack type putty.
You can get as fancy as you want with the supra-baffles, but I’d be inclined to make them the same width as the FH3s - would be approx 170mm if using 15mm material, and perhaps 225- 250 tall?
Seal behind with either foam weatherstripping tape or blue-tack type putty.
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Geez, I’d have thought cutting a rectangle would be easiest for most folks, but Dave can speak the the efficacy of a round SB. The only shapes I’ve ever fabricated other than rectilinear wer ellipses - and that because of access to a CNC.
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