Speaker choice for low watt SE-UL 6V6 amp

Hello, my first post

I have been looking for a speaker design for a low wattage SE 6V6 amp. I originally wanted to build the frugel-horn and like the design for it's simplicity but my problem is I don't have corners to place them in but I have a large room 20' X 30' with an eighteen foot cathedral ceiling. I started looking at other types of transmission line / horns. I like the funken series and also a double port rear loaded design which is too complicated for me right now. I found the straight voigt horn and from what little I can find for design specs I ordered a pair of audio nirvana super 8 drivers. (after I ordered I got a message that on vacation till April 3rd). I recently found the BIB calc site. I entered the specs for the an super 8 and it calls for a 118" line which is around 9' tall straight? I am guessing the folded length will be a slightly different freq? I don't mind the large size and the voigt pipes like large areas from what I;ve read. Not many sites left that address Voigt design so other than copying another voigt dimension I don;t have much to go on

I'm getting myself confused from over thinking what I want and thinking maybe a bass reflex box would sound just as good although the "ambience?" from TL horns is one of the qualities I like. Are my assumptions for a BIB Voigt pipe correct?

Am I overlooking anything obvious or not in making a choice? Thank you for any response.
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Hi Tom.


Big thread.

If I were you I and wanted a simple to construct box with a big room and low-wattage tube amps, I'd probably either 1) get a 12" or bigger full range (like the big Fanes) and put it in a bass reflex and live with the small sweet spot or 2) take the fast approach, sealed full range run off your valve amp and a cheap eq'd bass driver of your liking, fuelled by a cheap chip amp..

Good luck.
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That's definitely a big post and probably answer many questions. I saw fostex and figured it was too specific but with the calculator it makes it much easier. I eventually want to build a separate amp for each freq band. Not there yet but trying. I also can't afford the 12" drivers of the right quality.

I like the extra efficiency of the horns. Everything has it's give and take I suppose lol
I've been busy this week...I like the simplicity of the straight pipes. Other than copy someones else's and I don't have any calculator for horns / TL except the BIB calc which I like also. I can't find any dimensions for a straight pipe with the AN super 8 driver. My only real issue is no corner for a corner loaded full range speaker. I would build a small bookshelve or bass relex if it sounded as good as big pipehorn. I started reading through the links but still reading
the original Karlson - K15 (rules the roost w. good coax and solid-scrape) - not sure which FR would be best - you could try Fane 250 12" on an adapter ring retaining the cutout for 15" drivers. Brace the back - run short dowel's from K15's front shelf to the wings for front bracing. Star with 40.5 sq.in. port - narrow to taste (full width may be best.

GregB's Karlsonator 12 is tuned to 37Hz and will milk the good from 12LTA - K12H-200 - probably good with the real bargain ($69) PRV 10FR300. Add a JBL ST200 super tweeter to all of those.

Karlsonator12 pic is 3rd from the left in the top row - Jesse has that one loaded with a BG20 (too small a driver for that cabinet)

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Are the voigt pipes tuned to the freq you want or the fs of the driver? Tune to 40 hz or 56.90 hz ? It would seem like 40hz (or whatever low you want) and the driver would handle all the rest?
Line length is a half-wave size of the driver Fs (datasheet 57 ferrite). Last I knew/read, opinions varied on trustworthiness of factory data. Pragmatically, the choice is the trade between ~20ft3 (45) and ~10ft3 (57), basically. Figure out how big an envelope you can tolerate and use Hornresp to dial it in so the driver position (foor height) works for what you want. Go stand by your refrigerator and figure how much of that footprint you want, a little over your head (one fold) or 12ft tall (on up) and decide what you want to build. Nothing says you can't plan to "throw one away", either. If it's not fun, don't do it :)


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Joined 2004
If you have really high ceilings a BIB isn't going to be very effective, as it uses the ceiling as an extension of the horn. Kirishima or the Woden Audio Vulcan could work. I used a pair of Sachikos in a fairly large space for years running it off a 2W amplifier. I did use Fostex FE206ES-R drivers though.
Joined 2001
Paid Member
Note: haven’t read anything but post #1

the frugel-horn and like the design for it's simplicity but my problem is I don't have corners to place them in

Most are used near a wall. A Corner is only required if you have a driver like the FE126 Oif you want the lowest bass). The mosg commonly uswd ones do not.

20' X 30' with an eighteen foot cathedral ceiling

Lovely… a but smaller than my space (24x36 with 17’ vault)

Will greatly diminish LF room issues.

This one does need a corner.

Not many sites left that address Voigt design

A whack here.

Woden has published quite a few free Festival derivatives (the original paid plansets have expired).

We have current ones (folded into a monkey coffin) for the FED108e∑ (often favoured by SE owners), and the FF165wk. @Nandape started releasing a bunch with the same clever folding, His are somewhat more generik.


The driver i would be looking at would be teh MarkAudio Alpair 10p 0r 12p. Pensils are simple ML-TLs (with similar LF to a Festival).

If you want to go crazy, Woden Silbury or Avebury. They need a near wall. http://wodendesign.com/MA.html


A10p also fits Frugel-Horn XL, A12p in Joan.

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Joined 2001
Paid Member
Line length is a half-wave size of the driver Fs

A pipe is onlya half-wave resonator if it is sealed (or open at both ends). A voigt is a quarter-wave resonator. Note that they all really need mass-loading mto help tame th eripple. And that also gives you more latitude/degrees of freedome in the actual line geometry.

I was looking at the sachikos before but looks complicated to build. They do look nice though. I wonder how close are the FE206 and Super 8 as far as enclosure sizing?

That is the one thing about the BIB I don't like with the big hole on the top. I was thinking of hanging them in the ceiling but I was staying away from corner loaded designs. I don't have room for another **** or two. The voigt pipe I first saw had a smaller footprint. Vertical footprint isn't a problem. I'm blessed to live in the woods and have free lumber so I can experiment a little. My limitations are 2 watts (not really a limitation lol) and floor space in corners. Maybe try a couple different types.It does sound fun