Has anyone heard the Fibhorns from ebay yet?

[squirrelman]

I know there was this thread 3 years ago but there wasn't anyone that had tried them yet.

So my questions is has anyone tried the Fibhorn that is being sold on ebay yet? I'm looking for a pair of near field speakers to use with my computer, with a small SET amp (Miniwatt n3) with just 3.5 watts so I am looking for something efficient ideally. I'd like to use the FE126En ideally in there.

The reason I'm looking at something like this is I don't really have much in the way of DIY skills, so something basically done for me would be ideal. I was thinking of a Planet 10 flatpack but I don't know how to solder yet, so I'm not sure how well that would go.

 

[planet10]

I am only vaguely familiar with the Fibhorn, but have paid attention as the designer & manufacturer is a P10 client.

dave

 

[talaerts]

I wonder if fibonacci number progression makes a sensible choice for a horn profile.

 

[tilroh]

shouldn't they be mirrored?

 

[Scottmoose]

I wonder if fibonacci number progression makes a sensible choice for a horn profile.

I can't see it doing any harm. Whether it brings any real gains is another matter, but it's different, or at least presented differently, which is nice to see. 🙂 I hope they do well for them.

 

[EddieT]

Sounds interesting, the claimed low response is 38Hz. The enclosure weighs 11 lbs (sans driver). MDF weights vary by grade but one source says 2.19 lbs per sq ft. That would yield a weight of over 11 lbs for the box (sans interior partitions). I wonder if foamcore is used for interior partitioning?

 

[planet10]

MDF weights

MDF is not a sensible material.

Sally sent me some snapshots a while back and the ones of the inside show playwood (18mm would be my guess) construction.

dave

 

[bknabe]

Per the ebay listing;

The .5" MDF cabinet material is inherently non-resonant, and even more so because of the structural rigidity from the internal bracing parts.

 

[planet10]

I would not buy any horn made from MDF.

dave

 

[Scottmoose]

1/2in MDF is not 'inherently non-resonant' -a matter that is dictated by physics (or 'laws of nature' if you prefer). It is impossible to eradicate panel resonances, let alone with 1/2in MDF. All you can realistically try to do is shunt them to a region where they are less likely to be excited. In this case, the internal panels will brace the external ones somewhat, thereby raising their resonant frequency / BW. Whether it is sufficient to move them above of the cabinet's functional BW is open to question. Since MDF is not especially stiff, and has a relatively high density for a given thickness, I doubt it. Which doesn't mean I don't wish them well -I do. The more cottage-industries there are the better. I would like to see one in a quality void-free ply.

 

[rjbond3rd]

Interesting cab, but how can this be a horn? It looks like a TL.

 

[IG81]

An expanding path makes it a horn technically. The effective flare rate may be low enough, but the mouth diameter will prevent any kind of useful impedance matching until you get up in the hundred's of Hz. That is, not much of a resistive component in its acoustic impedance until way up high in frequency, where you may not wish to have output from the mouth anyway.

One of MJK's BLH article covers the issue pretty well and attempts to coordinate the TL and horn action of such enclosures into something useful.

 

[rjbond3rd]

So you're thinking that the path is expanding?

 

[Scottmoose]

Since they call it a horn presumably it is, by the Fibonacci ratio, albeit via a (probably small) number of chambers from what Dave mentions & what I recall from the previous thread / ebay listings.

As noted, if it expands toward the terminus, it's technically a horn since it will have a degree of 1/2 wave resonant behaviour -how much depending on how significant the expansion is. Fc just doesn't coincide with F0 (i.e. it's not impedance matched down to the 1/4 wave cutoff). It's hardly alone on that score of course.

 

[IG81]

So you're thinking that the path is expanding?

I think so, last time I saw the internals. I think the designer worked in the Fibonacci sequence in this expansion as well.

There seems to be a few versions of the Fibhorn, one with a full-width terminus and another with a smaller area, perhaps simply some mass-loading? Hard to tell without more detail.

 

[EddieT]

According to original ebay listing, 5 chambers expanding and vented according to fibonacci sequence. Stuffing in first 4 chambers. Later listings make no mention of stuffing but says driver chamber surfaces are stippled.

 

[FullRangeMan]

shouldn't they be mirrored?

Wow, 😱
Of course they should be mirroed.
Well noted.

 

[EddieT]

Sally has joined DIY and has made an initial post in the Vendor's Bazaar forum (http://www.diyaudio.com/forums/vendors-bazaar/278069-new-fibhorn-designs.html) but has yet to follow up. Here's an article with a peek into speaker assembly;
A sound business plan

 

[ruinevil]

Fibhorn 2

I actually bought the Fibhorn 2 about 3 weeks ago. I went to her showroom in Glens Falls, NY and heard the 2, 6, 7, and 9. They all sound alright, with the exception of the 6 with the Fostex driver, but her room is very congested with a bunch of furniture, and the second time I heard her speakers, her preamplifier ran really hot and pushed her amplifier into distortion.

Incidentally, MJK lives about 20 miles north of me, and 40 miles south of her showroom. I asked if they were ever in contact. She has never heard of MJK, and states her speakers are tuned by ear.

 

[jimbro]

I hope she's reading because aesthetically they need some work imo. The enabl patterns are sloppily done and don't match. The green "6a" looks tacky and again, sloppy. A small thing but wouldn't black screws be more appropriate?