The Big Littlehorn ? ...FE83En

[Bigun]

Big in sound, little in size (kind of dooms the idea of a horn doesn't it)

I'd like to have a go at some desktop speakers for a flea-power tube amp. I'd like something narrow (hence FE83En) to go either side of a wide LCD monitor and no taller than a typical monitor. Fostex recommens a "small BR or a BLH" for this driver. I think I can handle a design for a BR and I should probably build one of these....

but I fancy a horn and I don't know how to design a BLH option. I don't have design software or the experience to use it.

I'm looking for a short-cut, if there is one.
For inspiration I went to these places:

1/ http://www.diyaudio.com/forums/full-range/134257-backloaded-horn-fostex-fe-83-a.html
The Buschorn looks like one option, although it's taller than I want.
The Naga-Micro also looks too large.

2/ SpeakerBuilding.com - The High Fidelity Voights, Page 1
This Danish High Fidelity Voigt looks interesting. It's based on a larger driver but maybe a good starting point. It's about same height as the Buschorn. It's also not looking like a mass-loaded port like most Voigt Pipe's but more of a horn-fare loading? Which is a good lead-in to the latest option,

3/ http://www.diyaudio.com/forums/full-range/172605-frugel-horn-mk3.html
Frugal-Horn (FH3) with it's attractive 'Ron Clarke' curved back. I don't want to go off-topic in that thread so I've stared this one...

Since I can't model this kind of thing I have to wing-it by treating it like a folded Voigt Pipe.

The FE83 has a high Fs of 165Hz. How low should I tune a Voigt Pipe, can I get away with 120Hz ? - means a pipe length of 0.7m and I'll pick a mouth size of 1.5 x Sd for no good reason (this mouth will be the low pass filter to the horn flare too). I'll avoid a pointed end as I've read that this is bad for 'ripple' so I'll close it off with an area of about = Sd.

p.s. Scottmoose already warned me this idea is a little wild, and given I'm no speaker designer maybe I need to give up on this one here and now and save myself a lot of grief ?

 

[planet10]

It's based on a larger driver but maybe a good starting point... It's also not looking like a mass-loaded port like most Voigt Pipes

Mass Loaded voigts are actually a fairly new phenomenom, althou sometimes seen in the past, Martin Kings ML-TQWT article laid down the quantitative framework for taking advantage.

Most traditional voigts have no mass loading and typically suffer from large amounts of ripple.

dave

 

[Scottmoose]

Desktop & horn, esp. a rearward firing one, is basically a duff combination. The 83 isn't thrilled at being tuned much below its Fs, there's no time for proper integration, nor sufficient space between them & you also say you've a monitor etc. in the way hashing things up still further. The results are likely to be a complete mess, above all as you're not sure what you're doing. Sorry, but I'd rather say that now & possibly save you from wasting your time & money than say 'go ahead' while knowing the results you get are likely to be poor.

 

[Bigun]

So, the issue is that I'll have the sound from the front of the cone arriving pretty quickly and the sound from the horn mouth arriving much later, with the monitor being stuck in the way. Hmmm. Well at least now I 'get it' and it makes sense to me. Darn it. But thank you !!

So I am learning that for near field monitors I want to have all the sound coming out from the front of the enclosure. This keeps the path length of the sound to my ears roughly the same and keeps it away from the back of the monitor.

Last question on horns then - is a Front facing horn possible ? perhaps a BVR, something to give me a bit of gain at low frequencies where small drivers are poor ?

 

[Scottmoose]

Partly, but the result is similar.

Nearfield monitors are best sealed, aperiodic, TL or vented IMO. Not necessarily the most exciting, but nearfield monitors aren't really the best type of enclosure for experimenting with some of the more extreme forms of cabinet load. You're too close, & the boxes & space is too small, so direct radiation & as near to point-source as possible is what's needed.

The 83 doesn't do quality bass (let alone achieve a reasonable dynamic BW) in anything other than a full sized horn.

 

[chrisb]

Partly, but the result is similar.

Nearfield monitors are best sealed, aperiodic, TL or vented IMO. Not necessarily the most exciting, but nearfield monitors aren't really the best type of enclosure for experimenting with some of the more extreme forms of cabinet load. You're too close, & the boxes & space is too small, so direct radiation & as near to point-source as possible is what's needed.

The 83 doesn't do quality bass (let alone achieve a reasonable dynamic BW) in anything other than a full sized horn.

However, the late lamented FF85K in a small aperiodic enclosure is silly good, from near to moderate listening distance (of course in larger spaces, bass augmentation is required)

 

[Bigun]

Hmm, perhaps the Henkjan TL box originally designed for the Alpair5 is something I should look at - some of the key driver specs aren't so different from the FE83En.

Yes, the demise of the FF85K isn't so good.

You know, I've only really made one set of DIY speakers which allowed me to hear the Fostex 127's and apart from the 7kHz peakiness I like them very much. It makes me nervous to consider something other than a Fostex - in this case the FE83En.

There are some less expensive 3" drivers available, but I've no idea about their pedigree ?

3" paper cone from Hi-Vi:
https://www.madisound.com/store/product_info.php?cPath=45_241_282&products_id=8831

3" Al cone from Peerless:
https://www.madisound.com/store/manuals/830987.pdf

3" from Fountek:
https://www.madisound.com/store/manuals/fr88ex.pdf

 

[Scottmoose]

Hmm, perhaps the Henkjan TL box originally designed for the Alpair5 is something I should look at - some of the key driver specs aren't so different from the FE83En.

...the difference being that the A5 can be tuned rather lower. It's still not a good idea to take it too low, but it's happier than the Fostex. TBH, I'm not a fan of the 83, unless it's high-passed with supporting woofers.

 

[Ty_Bower]

I'd like to have a go at some desktop speakers for a flea-power tube amp. I'd like something narrow (hence FE83En)...

...The Buschorn looks like one option, although it's taller than I want.

I built a Buschhorn (mk.I, the original version) and I am consistently amazed by its performance. The output seems to defy what should be possible from the 3" FF85K in it. As you note, it is quite a bit too tall to set on your desk next to the flat panel display. I think Dave described it as a "tiny floorstander".

I also built a set of Makizou M-8BH clones. They are quite a bit shorter than the Buschhorn, and the mouth exits from the front of the enclosure. These might suit you better? I installed a pair of FE87e in mine. They don't perform as well as the Buschhorn, but I do think they sound good. I'm pretty sure I heard something special when I listened to them for a while, and that partly drove me to build the larger Buschhorns. You will find a lot of my notes about the Makizou in this thread:

http://www.diyaudio.com/forums/full-range/81133-makizou-i-finally-did.html

 

[chlorofille]

Hi Bigun,

for nearfield listening, I recommend the Vifa 3.5'' fullrange fibreglass cone.

It has a rising response from 1000Hz to 200Hz which sort of acts as a baffle step compensator. I have them in a 4L vented enclosure which boosts the low end by 3dB to make nearfield bass acceptable. I run them direct without any filters and they somehow sound full and rich.

 

[Bigun]

... the A5 can be tuned rather lower. It's still not a good idea to take it too low, but it's happier than the Fostex.

To be honest, I've counted-out using Alpair as I feel that, compared with most of the drivers I'm looking at, they're over-priced, not as sensitive for their size and often have a lower impedance. Plus, the A5 is discontinued. I suspect that I'd be paying extra just for the 'looks' - and they do look good!

I also built a set of Makizou M-8BH clones. They are quite a bit shorter than the Buschhorn, and the mouth exits from the front of the enclosure. These might suit you better?

Thanks - interesting read and a nice build by the way. Something for me consider. I gather there are a lot of small speaker projects in Japan. I lament the fact that in the West we seem to focus on Big speakers and have not developed very much art for the smaller speaker - which is surely of interest to people who can't afford mansions or have WAF factors weighing on them. Thank goodness for Google Translation !

Hi Bigun, for nearfield listening, I recommend the Vifa 3.5'' fullrange.

Thanks for the suggestion, these drivers do look interesting. Alas, with an Re of 3.2Ohm I don't think they'd be my first choice for a tube amp (although my current tube amp would be able to put out more power with these).

I'm surprised nobody talks about the Fountek, it looks rather good on the spec sheet. I suspect, like amplifiers, spec. sheets are only a starting point to understand how well they might perform. Without listening impressions it's a shot in the dark to use them. Still, I like the idea of widening my horizons.

 

[planet10]

To be honest, I've counted-out using Alpair as I feel that, compared with most of the drivers I'm looking at, they're over-priced, not as sensitive for their size and often have a lower impedance. Plus, the A5 is discontinued. I suspect that I'd be paying extra just for the 'looks' - and they do look good!

Alpair 6 is really a fairer comparison to the Fostex 3". From the early protos of the new Alair6P i have here they could well be challenging FF85 (which IMO is one of the best drivers Fostex has built) and any of the 6s -- new or old -- already have much greater LF capability. And given the improvements the Gen2 metal drivers have seen the Alpair6M should kick butt too. Do keep in mind that these drivers are being heavily influenced by a number of the top Fostex people directly responsible for the last generation of FE & FF drivers (at the least).

dave

 

[Bigun]

no argument from me, the Alpair 6 does look very nice, very handy frequency response. If only it weren't half the impedance, 3dB less sensitive and twice the price of the Fostex there would be no hesitation. But it's definitely worth consideration.



Ty-Bower, If you still have that Makizou, if it isn't too cheeky to ask, would you be willing to do the experiment of placing them on a computer desktop either side of the monitor and letting me know how it is ??????

 

[Scottmoose]

I wasn't suggesting using the A5 for fairly obvious reasons. What was am pointing out is the dissimilarity between the drivers, and the fact that the Fostex unit will not thank you if you try using it like an Alpair.

Trying to get quality LF from the FE83En is like trying to get blood out of a stone. It's got 0.15mm linear excursion, a high Q &, low Vas. Not a happy combination if you want LF. A small aperiodic TL, aperiodic or sealed box is about the best you're going to get in terms of a decent response (forget bass) short of a full-sized horn. It's really going to be happiest as a mid-tweet.

 

[d to the g]

the desktop miniparagon (with fostex drivers)

I wouldn't mind having one on my desktop. Takes up a bit more space though.

 

[chrisb]

I wouldn't mind having one on my desktop. Takes up a bit more space though.

now this is just too damned cute, and quite a piece of craftsmanship

kudos to the builder

 

[Bigun]

I've never heard of or seen these kinds of speakers - JBL xxx'gon series. Looks very interesting though. Can't find anything to read about them and nothing about these particular units.


Well, since the challenge of 'pushing' a small single full range driver to cover a wide range in a small box will be at the expense of a nice sounding speaker I shall have to leave the LF behind and focus on mid-hi.

I'll give this a bit more thought, but you are convincing me that the FE83En big littlehorn doesn't look favourable.

 

[chrisb]

I've never heard of or seen these kinds of speakers - JBL xxx'gon series. Looks very interesting though. Can't find anything to read about them and nothing about these particular units.

to be specific:

PARAGON


but do yourself a favor and take an evening off from the DIY forums, brew yourself a pot of your favourite coffee or tea, and dive into the


LIBRARY



on second thought, it might take the better part of a long weekend to do it justice


take note of some of the early dates


When Cal gets around to building his man cave, he'll probably go for something like:

subs are included 😉

 

[Bigun]

Thanks Chris ! - just the ticket for feeding my currently voracious appetite for reading material.

A break is indeed in order this weekend - I'll be slinging some solder around some vacuum tubes....

 

[hm]

Bigun

Hello,

your driver will not work good,
look the lin. stroke 0.15 mm,
it is more a driver for a fast construction
crossed at ~ 500 Hz with a bass mid driver
6.5-8" driver.

i made a small horn sat down to 100 Hz
but would prefer another driver,
look on my HP the flute-sat: