Frugel-Horn Mk3 Builds & Build Questions

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I took my set to CKDIY last weekend. The drivers are a no-name 4" from Meniscus and the Dayton ND16FA-6.
I'll have these in front of a mic later this weekend. I plan to do some response shaping.
The bass output will satisfy. String bass remained at satisfying levels in a large room.
 
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This is one side of the EnABL listening session. The other side was oriented with the lighter speaker to center. The sealed 2-ways are in OSB cabinets. Someone dubbed the lighter one "Straw Bales"...it stuck. The drivers are Silver Flute W14RC25-S-08 mid-woofers and a Vifa oem tweeter of BC26 pedigree.

I didn't give much of an introduction to the session. I did explain that I would be switching between the two sets of speakers throughout the session. I did announce which set was being heard, "A or B", without identifying which was the EnABL pair, until after.

Participants remarked on the increase in soundstage width and instrument placement within it. Some thought the crossover was the variable being evaluated. Those found it surprising that the difference was the cone treatment. Nothing scientific here. My purpose was to give participants an introduction to EnABL.

The cap session hasn't been written up by Wolf yet. This is the "unauthorized" version... It included 3) A-B-X segments. The music selections were identical for each segment. Two cap combinations were heard (A & B) and then we were challenged to tell which of A or B was heard in the third segment.

The first segment included 2 very good caps, one of which was the Clarity SA. I could not tell which one was being played as the "X" selection and answered with a "?".

The second segment was a comparison of series caps on BOTH the tweeter and mid-range, using mylar caps compared with Poly caps. I thought I could tell the difference and was correct.

The third segment was a comparison of NPE caps with poly caps. I thought I could tell a difference and was correct.

One participant sitting next to me was puzzled by the session. He asked what to listen for, so another round was conducted with the expressed intent of education. I felt he was not too happy with not being able to "hear" what was being spoken of.

I'm convinced that caps each have a unique sonic signature. One must combine an exposure to those differences along with an acquired knowledge of "where to listen" within a selection of music in order to "hear" them.
 
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This is one side of the EnABL listening session. The other side was oriented with the lighter speaker to center. The sealed 2-ways are in OSB cabinets. Someone dubbed the lighter one "Straw Bales"...it stuck. The drivers are Silver Flute W14RC25-S-08 mid-woofers and a Vifa oem tweeter of BC26 pedigree.

I didn't give much of an introduction to the session. I did explain that I would be switching between the two sets of speakers throughout the session. I did announce which set was being heard, "A or B", without identifying which was the EnABL pair, until after.

Participants remarked on the increase in soundstage width and instrument placement within it. Some thought the crossover was the variable being evaluated. Those found it surprising that the difference was the cone treatment. Nothing scientific here. My purpose was to give participants an introduction to EnABL.

interesting how some of these "unscientific" tests are very revealing of what people actually experience :rolleyes: (no emoticon for ducking for cover?)
 
frugal-phile™
Joined 2001
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This is one side of the EnABL listening session... Silver Flute W14RC25-S-08 mid-woofers and a Vifa oem tweeter of BC26 pedigree.

Participants remarked on the increase in soundstage width and instrument placement within it.

The W14 is a nice piece of kit... i have a pr of 8 ohm and a quad of 4 ohm here (all fully done up).

If one knows going in to listen for soundstage, it should be pretty easy to pick the EnABLed set every time.

dave
 
drivers of interest

Measurements from the Meniscus no-name showed a ~5 dB dip in the response from ~2500 to 4700 hz...leading to a decision to shelve them for better days.

Fortunately, all was not lost. A Tang Band W4-1302SJ 4" Bamboo Cone was available and installed in the Frugels. Measurements confirmed what our ears told us...we have something to work with here.

RJB Audio has worked with this driver and provides background and suggestions for a contour network.

Bandit

Roman's site includes a nice feature for viewing the changes in response that occur with moving off-axis.

Based upon this evening's listening I want to consider other economical alternates. The Tang Band W4-1052SD will be acquired and run through its paces. This driver has been proven to have merit in the "Whetstones" by Taterworks over on PE TechTalk.

Whetstones - Taterworks Audio

Another Tang Band driver which I already have is the titanium cone W4-1337SD

And last, I'll pick up a W5-1611SA.

The time is right for Tang Band drivers through tomorrow. They are on sale @ PE for 25% off.
 
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Went looking for plywood today ... Found smooth pure blond sheets of birch plywood, with two good sides per sheet. Wasn't expensive.

The guys at the store evidently liked the FHmk3 design, showing interest and asking questions. For instance they asked whether the curve at the back only looked good or if it was for acoustics too. I'll drop by with better drawings at the store in the next days – I think they'll be able to arrange a CNC job for not much money.
 
Went looking for plywood today ... Found smooth pure blond sheets of birch plywood, with two good sides per sheet. Wasn't expensive.

The guys at the store evidently liked the FHmk3 design, showing interest and asking questions. For instance they asked whether the curve at the back only looked good or if it was for acoustics too. I'll drop by with better drawings at the store in the next days – I think they'll be able to arrange a CNC job for not much money.


Make sure they understand that as simple as the cabinet looks in terms of number of parts, there's several years of calculation and iterative construction behind the drawings, and yes the curve is functional.
 
Make sure they understand that as simple as the cabinet looks in terms of number of parts, there's several years of calculation and iterative construction behind the drawings, and yes the curve is functional.

Yep, thanks. I'll be specifying all the pieces down to sub-millimeter accuracy, letting them know it needs to be accurate; I'm giving them precise and clear dimensional drawings, and will be cutting the curve myself. Only the paranoid survive ...

And yes, exactly! - People always ask that - is the curve functional? :)
 
Yep, thanks. I'll be specifying all the pieces down to sub-millimeter accuracy, letting them know it needs to be accurate; I'm giving them precise and clear dimensional drawings, and will be cutting the curve myself. Only the paranoid survive ...

And yes, exactly! - People always ask that - is the curve functional? :)


well, sub-millimeter accuracy might be a bit excessive (have you accounted for thickness of glue-line? ;))
 
Hi
I just completed a pair of FH3. A lovely design and a very simple build. I first made an accurate template for the sides from 9mm high quality ply. I used this to draw the shapes for the sides, onto 18mm furniture grade baltic birch ply, which were cut slightly oversize on the bandsaw. I fixed the template to each of the sides with a couple of screws to finish off with a flush trim router bit.

The fronts and internal panels, including angles were all cut by bandsaw.

The hole for the driver was cut by hole saw and then chamfered on the inside with the router.

When gluing up, I started with the front, then bottom, top, back then centre, making sure each panel was perfectly square to the side by using a square. When dry, simply clamp on the other side to complete the sandwich.

Have tried several glues, but like Bison pu Timbermax in cartridge. Very strong bond, easy application, slightly gap filling and easy cleanup when dry.

I am waiting for veneer to arrive. Any advice on driver choice would be welcome. I quite like the look of Alpair 7.
 

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Edit: dave beat me to it.

FH3 is designed to be relatively flexible / accept a reasonable range of drivers. Baseline are the Mark Audio CHR70, CHP70, & the CSS branded EL70. The A7 has also been used to good effect. The FE126En also works but as you would expect, this provides a somewhat more damped alignment which is best corner-loaded.
 
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