I've been looking into Frugel-Horn XLs as I'd like to build my own speakers for mostly low level listening. Having limited woodworking experience and tools, I'm looking at a kit from KJF Audio but have a few questions I'm hoping the hive mind may be able assist with.
Firstly - does anyone have experience of the KJF kits and whether they are a good quality product?
Second - would a Pluvia 11, Alpair 11 or Alpair 10.3 give me the least bright sound in the XL box?
Firstly - does anyone have experience of the KJF kits and whether they are a good quality product?
Second - would a Pluvia 11, Alpair 11 or Alpair 10.3 give me the least bright sound in the XL box?
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I'm slightly biased as Stefan is a friend and colleague, but I have no financial involvement with his kit sales, and speaking foremost as FHXL's designer, I can assure you his kit quality is superb; the material, rebates, instructions etc. are all first rate. I wouldn't say so if they weren't, as it wouldn't do anybody any favours at all -yourself / other buyers, him, or Dave & myself.
Regarding the second question, like all bass loads FHXL only operates at lower frequencies above which you're simply listening to the direct radiation of the driver. Bass loading can have an apparent influence higher up the range, but that's a specific area of psycho-acoustics which isn't particularly relevant in this case. Of the three, 11MS probably has the balance you 'sound' like you're looking for; 10.3 is now defunct, with CHR-90 effectively being a variation on it [it shares some components] at a lower price; it arguably has a little more HF energy than 11MS, while Pluvia tends to sound a little more so again, albeit actually for reasons slightly lower down the range.
Regarding the second question, like all bass loads FHXL only operates at lower frequencies above which you're simply listening to the direct radiation of the driver. Bass loading can have an apparent influence higher up the range, but that's a specific area of psycho-acoustics which isn't particularly relevant in this case. Of the three, 11MS probably has the balance you 'sound' like you're looking for; 10.3 is now defunct, with CHR-90 effectively being a variation on it [it shares some components] at a lower price; it arguably has a little more HF energy than 11MS, while Pluvia tends to sound a little more so again, albeit actually for reasons slightly lower down the range.
Thanks Scott, really appreciate the reply. Would the CHN-110 also fit in the FHXL without alteration?
Great, decisions to be made! Apologies for the many questions but I've seen that lots of folks run the FHs off small tube amps which I don't have, mine is pretty gutsy Roksan K3(150wpc in 8ohn, 220w in 4), is this likely to affect how I need to stuff the FHs at all?
No, the default should be fine; solid state and amplifiers with up to a modest output impedance was the default assumption & it tends to be those with a higher output impedance [e.g. typical SET types] that tends to need more, at least with middling-Q drivers like the Markaudio units.
Second - would a Pluvia 11, Alpair 11 or Alpair 10.3 give me the least bright sound in the XL box?
Alpair 10p. What iterm “vintage” top-end. Mabe CHP-90, haven’t heard bit, but AFAIK largely a development on A10p.
P11 is not in the same league as the other 2. 1 or more coats of acrylic gloss can bring the top down. I use 2 coats to help with HF ringing, more coatsnshould slowly reduce HF amplitude (educated guess)
dave
CHN-110 is a stonking driver for really cheap… sounds good in my FHXL, but Scott suggestsb it would prefer the slightlyn larger Joan,
dave
dave
I built the CHN-110 in the Joan, and it is quite amazing in that setup.
I've seen nothing but good reviews on the CHN-110 but unfortunately, can't get the Joan boxes in kit form in the UK from what I can see online. My woodworking abilities aren't advanced enough for me to do it myself and make a professional job of the cutting so it may have just have to be the FHXL with the CHN-110 if I can get the baffles cut correctly from KJF.
I'll mention it to Stefan -I need to have a word [that sounds like an east-end crime boss 😱 ] with him anyway. I suspect he'll be on a river in Wales over the weekend, but will try to get hold on Monday.
It will work in FHXL -in that case you will need some extra damping though, as it prefers a larger enclosure.
It will work in FHXL -in that case you will need some extra damping though, as it prefers a larger enclosure.
Thanks Scott, much appreciated. I'm just watching the KJF Audio video on YouTube about the CHN-110 driver, it's a nice looking unit
A couple of years back, Stefan & I went down to his brother-in-law's place for the weekend to do some fine tuning on his SL series speaker kits; one of the objects with that one was to be able to use the same enclosures with CHN-110, Pluvia 11 & Alpair 11MS, with minimal changes [a minor vent length trim in one case]. Different LF alignments of course, but all functional. Ignoring that -the standouts for us were the CHN and 11MS. You can tell the family resemblence, although the latter is significantly ahead of the other two; it basically does everything except outright extension potential better. In that sense, you do get what you pay for [alas
]. But the sound / £ ratio of CHN is very impressive -in outright terms, it's just a very good, usable, flexible, 'doesn't do anything objectionable' driver. Which to me is priority no.1. Everything else is a bonus.

The Speakers would be going in a reasonably large room(6m by 4.5m by 2.5m) so the extra bass availability on the CHNs would definitely be beneficial from my, admittedly limited, understanding(I'm doing my best to learn though). If the 11ms are going to work better in this situation and still have adequate bass for the room, I'm more than happy to go with those?
The potential extra bass extension of CHN only applies to enclosures specifically designed to exploit it [which does come with its own penalty -you don't get anything for nothing in audio]. Personally, I'd just get 11MS and have done with it. It's worth the extra, and in FHXL it's not lacking in LF for a driver of its size -the first time Mark Fenlon heard them in that enclosure, at the North West Audio Show some years ago, he was a happy man. Which was no surprise, as they were working very nicely that weekend.
Thanks Scott, as the man that designed the speaker enclosure, I'd be silly not to take your advice. It will also give me an excuse to build a second set of speakers in the future 😀
the first time Mark Fenlon heard them in that enclosure, at the North West Audio Show some years ago, he was a happy man
Mark was kinda stunned when he first heard FHXL (with A10PeN) at Chris’ he was stunned. Couldn’t really belive it, asked us to play it again.
FHs have been a very successful design.
dave
One of. Dave & Chris did the lion's share of development work & creating the plansets etc. -I know one end of a ruler [and hammer] from the other on a good day. 😉Thanks Scott, as the man that designed the speaker enclosure, I'd be silly not to take your advice. It will also give me an excuse to build a second set of speakers in the future 😀
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