[FreedomJazzDance]

Hello to all, I'm new on the Forum, you can read my introduction at the The Starting Block / Introductions. 

On the recent days, I was researching a lot about different types of amplification and loudspeakers, and I made a decision:

My first high end system, (I think in compare with my previous system, it will be very high end anyway hehehehe) will be:

Tube amplification with Back Loaded Horns, on a vinyl playback dedicated system, I think will be a great experience listen to music in a way that will be very different from what I'm used to.

So, let me tell the first doubt that I have, about the knowledge that is needed in order to assemble this system:

The drivers that I will use for the speakers are: 8" Fostex Full Range Driver FE208EZ, and Fostex Super Horn Tweeter T900A

The enclosure will be the recommended one by Fostex for this drivers. (It's okay put the links from Fostex website, of the drivers and enclosure here? please let me know)

I would like to start with this:

For what I researched, the match of SET amps and Full Range Drivers, besides the relation of low power and high speaker's sensitivity, is also very much related to the fact that SET's have a low damping factor ( high output impedance), and Full Range Drivers likes very much low damping factor amps, because on the contrary, the drivers will be overdamped by the amp, and the bass performance will suffers a lot, makes sense?

Also, feel free to contribute with other technical insightful infos, that you think are relevant about tube amplification and this speakers.

Thanks everybody, looking forward to learn with more experienced people and share my journey with everybody.

Many thanks, best regards.

[FreedomJazzDance]

Edited in order to keep the thread more concise.

Any thoughts about the relation of: SET's damping factor and the relation with full range drivers?

Looking forward for the advices, and enjoy the learning process with more experience Low Wattage System's users here on the Forum.

Thanks everybody, best regards.

[Tyson]

I have some experience with SETs, but not driving any single-driver speakers.  Do you already have an SET amp and are looking to get a good match for it?  Or do you already have a single driver speaker and are looking to get an SET to match it?

[Bemopti123]

I have some experience with SETs, but not driving any single-driver speakers.  Do you already have an SET amp and are looking to get a good match for it?  Or do you already have a single driver speaker and are looking to get an SET to match it?

  It seems like he is contemplating both steps at the same time.  He is in the planning stages and that is the hardest thing to do, both of the variables will be new to him.  I would get speakers first and then...pair it with an affordable SET...as those speakers he has in mind are fairly efficient. 

[oldnuke]

I have those speakers but not in that enclosure anymore.  They were better in a large open baffle with a 15" helping out on the lower frequencies.  I have a pair of Frugal Horns (back loaded horns) that I love, they can play without any low frequency help but can use a tweeter.  All will depend on the SET you decide to use, a 2A3 will give you a couple of good watts, a 45 a watt or two, 300B 5 to 6, EL84 6 to 8 (I think).  You will have to decide on the match, but with all SET's get the highest efficiency you can because you don't have a lot of power to throw around.
Will you be listening near field or is the room a cavern?

[FullRangeMan]

I have those speakers but not in that enclosure anymore.  They were better in a large open baffle with a 15" helping out on the lower frequencies.  I have a pair of Frugal Horns (back loaded horns) that I love, they can play without any low frequency help but can use a tweeter.  All will depend on the SET you decide to use, a 2A3 will give you a couple of good watts, a 45 a watt or two, 300B 5 to 6, EL84 6 to 8 (I think).  You will have to decide on the match, but with all SET's get the highest efficiency you can because you don't have a lot of power to throw around.
Will you be listening near field or is the room a cavern?

+1 on the Frugal Horn for his Fostex 208.
According Steve Planet 10 in other topic, Frugel Horn have much gain in the bass that seems perfect for the dynamic music styles he listen

EL84 6 to 8 (I think).
Maybe you mean say EL34, a sweet sound tube and not flea power that its a good match to his speakers.

[Bl4des]

Nice

[FreedomJazzDance]

I'm grateful for the disposal for advice me guys.

Let me answer some of your questions, an update about the ways that I'm considering to choose, and some doubts that need to be clarified.

I done some calculations this days, and the previous combo that I posted will not fit my budget.

Here's what I'm looking for and need some clarifications about:

My listening room now is not so big, around 6 meters by 6 meters, but I have plans to move for a bigger listening room in a near future.
Maximum budget for full range drivers for example (including  super horn tweeters) is 1100 dollars.
I like to listen loud too, up more than 95db
Don't have the skills to build, but there's a nice woodworker here with experience in build loudspeakers.

One important addendum related to the budget, my only option is for drivers that have distribution in Japan, buy locally where I live is very expensive, as well import via mail order due outrageously expensive tax, but I have a good friend in Japan that can buy and bring personally the drivers for me, that's the main reason about by choice for the Fostex drivers, besides they be a renowned brand too.

I'm considering this two systems by Fostex.

Full Range Driver + Super Horn Tweeter, with recommended enclosures

Option 1.

Fostex FE206EN + Fostex T90A + Fostex recommended enclosure

[URL unfurl="true"]https://www.fostexinternational.com/docs/speaker_components/pdf/FE206En.pdf[/URL]

[URL unfurl="true"]https://www.fostexinternational.com/docs/speaker_components/pdf/t90arev.pdf[/URL]

[URL unfurl="true"]https://www.fostexinternational.com/docs/speaker_components/pdf/recom_enclose/206e_enclrev.pdf[/URL]

Fits on my budget with considerable headroom, I can save 390 dollars.

Option 2.

Fostex FE208-SOL +  Fostex T90A + Fostex recommended enclosure, (enclosure for this one is on the manual sheet of the driver)

[URL unfurl="true"]https://www.fostex.jp/products/fe208-sol/[/URL]

https://www.fostex.jp/wp/wp-content/uploads/2017/09/FE208-Sol_Manual.pdf

Fits on my maximum budget.

Doubts about the performance of this 2 systems:

Would like to understand more about the difference in prices about this 2 systems, mostly because the differences specs of FE206EN vs FE208-SOL. I'm not too versed on deep technicals terms, so I appreciate the patience e simplified language in order for me to start understand the differences.

I noticed that the FE208-SOL is a much heavier unit, 8,7kg, meanwhile the FE206EN weights 3,2kg, I think this is related for a more high end motor magnet on the FE208-SOL? and also a much more over damped driver? It's correct to assume that? What will be the implications about this on the sound quality?

Also, I would like to understand more the differences showed on the impedance curve graphic of this 2 drivers, and the implications on the sound quality, for example: I noticed on the FE208SOL, there's a line that goes down till number 20 on the left column scale (that have a dB unit of measurement), meanwhile the FE206EN goes till the number 50 on this scale, what this means?

Also, all other infos that you can provide about the differences between this 2 drivers, are very much appreciated.

The recommended enclosure for the FE208-SOL is more complex to build.

Many thanks guys.

PS: I also open to receive suggestions of different enclosures plans, and drivers brands that fit my budget, but as I explained, it's important for me that they must have distribution in Japan, also, would like to know if there's more Japanese driver's brands to look for, as I only found Fostex.

PS: My focus for amplification is SET, but let's take the amp possibilities out of the equation now, in order to not overblown my mind with too much variables at once.

[FullRangeMan]

Full Range Driver + Super Horn Tweeter,
I should advice against the tweeter and a xover, you will loss the harmonics, 3D soundstage and spend more.

I though you purchased the Fostex 208 that is 97dB that fit to a 2A3 amp or better yet a 6/8W EL34.

[FreedomJazzDance]

Change of plans, just noticed that the limited edition FE208SOL is sold out in Japan, but still interested to know the clarifications about the differences between FE208SOL vs FE206EN.

[JLM]

Note that horns are rarely braced sufficiently to avoid colorations (from flexure of the horn walls due to relatively high stresses).  Use of a small tube amp (typically with poor damping factor) with horns just mixes two colorations together hoping they cancel each other out.  Raves of this combination come from many a proud papa, not independent and experienced listeners.  And for horns to go truly deep they need to be huge, at least the size of a walk-in closet, which makes the needed bracing extremely heavy.  That's why lovers of small tube amps have for the most part forgotten what deep bass sounds like, and in fact freak out when they do hear it.  (I hung around SET lovers for years before giving up on that path.)

Another problem with extended range drivers and small tube amps is lack of life like sound pressure levels (volume).  Classical/jazz peaks around 105 dB, rock around 110 dB.  In a room like yours, 95 dB/w/m is about the best you could expect with FE208 and a SET, thus most fans of this approach gravitate towards listening to small ensembles at late night volume settings in smaller rooms.  OTOH those for those circumstances its hard to beat this combination.

And in a squarish room 6m to a side, you'll have a large bass peak from the room around 60 Hz.  Recommend reading Floyd Toole's "Sound Reproduction", 3rd edition to learn how rooms behave and the need for multiple subs to even out the bass response peaks and dips (which is +/- 7 dB in my non-square treated room using 3 subwoofers to even out the peaks/dips).  Note that this is the result of the room, not the main speakers or their placement, and that DSP/EQ can only offer a partial solution (should only be applied as icing on the cake).

How young are your ears?  In the opinion of my old ears I'd say the FE208 lacks bass more than treble.  The FE208 (like nearly all Fostex 8 inch diameter drivers) is far from my favorite driver: weak bass and mid-bass, forward/shouty midrange, lots of nasal colorations, and uses a whizzer (mechanical crossover which I despise).  And it's low Qt pushes for the use of rear loaded horns.  It does have good efficiency, but that's not enough to justify all it's faults.  Alpair or Tangband would be better alternatives.  So I'm suggesting looking at smaller drivers with bigger amps.

[FullRangeMan]

Also consider the Nirvana Classic10Ferrite $375 pair, 99dB in a box David Dicks atend very well, yet works as OB(96dB) and horn Qts=0,23
https://commonsenseaudio.com/an10classicspecs.jpg
The Audio Nirvana 'Classic 10 FERRITE' ($375/pr) has a test bench frequency response from 33 hz to almost 20,000 hz (varies by temperature). You can expect at least 99 db efficiency in any of our cabinets. It handles 30 watts continuous RMS (normal listening level will be about 1/10 watt). Impedance is 8 ohms. Voice coil is 1.4 inches (35.5mm). Magnet weight is 3.2 lbs. Total weight is 9 lbs. The cone is made of paper. The surround is accordion style and made of treated cloth. The dust cap is a specially coated fabric material. The frame is cast aluminum.

[JLM]

Good idea to have amp and speaker in mind when starting out.  But I'd pick the speaker (to fit your room and musical genres) first then find an amp to serve the speaker.  I was there almost 20 years ago.  Tried to warm up to SETs and efficient single driver speakers.  But couldn't find a satisfactory solution.  The limited power of SETs demanded giving up bass to provide decent volume without going to very high efficiency (and uber expensive) drivers which inevitably had colorations (as mentioned in my post above).  But still wanted the coherence only available from use of a single driver.

So 16 years ago went with a Fostex F200a extended range driver (30-20,000 Hz, 90 dB/w/m, 8 ohms, AlNiCo magnets, $575 when last available) and commissioned floor standing transmission line cabinets for them and over the years have paired them with a variety of amps (7 - 100 wpc).  The 7 wpc was a tiny battery powered amp I had on hand, it did a remarkable job.  But moving up to 40 wpc (solid state and tube) added more dynamics and better (more commanding) grip for improved detail and imaging.  The last couple of amps have added even more dynamics and clarity and up'd the power to 100 wpc.  So my message to you - don't skimp on the wattage. 

There is no perfect speaker.  Even my F200a/transmission line speakers aren't perfect.  They barely reach live concert levels in my room and without a whizzer, "beam" above 4,000 Hz.  But they are tone monsters and have found an amp that minimizes their other shortcomings (dynamics, ultimate detail, and extending the highs).  Small extended range drivers are less efficient and have lower ultimate output, but can easily do without a super tweeter.  Larger extended range drivers are more efficient and have higher ultimate output but need whizzers or super tweeters and like any other speaker need multiple subs to address room peaks/dips.

Your proposal amounts to trying to short cut the learning curve.  Proper shopping for pre-built speakers is hard enough to do.  Could take years to travel for auditions, then would still have to take different rooms, setups, and amps into consideration.  Trying to do that with a variety of drivers/kits/plans would be near impossible to do it right without years of experience.  That's if you can find the driver/cabinet combination you're looking for.  And horns are the most difficult cabinet types to properly build. 

[FullRangeMan]

JLM you makes think a planar headphones are the easy solution, the amp required also is smaller.

[Bemopti123]

Change of plans, just noticed that the limited edition FE208SOL is sold out in Japan, but still interested to know the clarifications about the differences between FE208SOL vs FE206EN.

I have the 208SOLs.  The main difference is that they have huge ferrite magnets.  They have glued 2 in place making the driver very heavy.  Even heavier than the older whizzle cone 208 Sigmas from the middle 2000s.  According to what I have read, the older whizzled Sigmas sound a lot better than the latter whizzleless Sigmas.  The later Sigmas with the really cool sculptural paper cones look cooler though. 

If I were you, I would just get one of the standard 208s because you will cross them into a bullet tweeter in the upper range.  Build the cabinets, enjoy them until Fostex decides to release another batch of special edition models and then if you curious, you can swap out the drivers.  The Fostexs need hundreds of hours of break in.

[FullRangeMan]

My listening room now is not so big, around 6 meters by 6 meters, but I have plans to move for a bigger listening room in a near future.

FJD,
Sorry for the bad news, seems your room is huge and not suited to a FR driver.
I afraid this room is too big to any know FR driver, no one hi-fi FR driver can fill a 36M² room with useful SPL to please a musiclover. Usually a FR driver have limited power handling around 20-30W only.

I could suggest you a planar headphone as HifiMan 400 series or a used Edition X and a small tube amp as Decware Rachel EL34 at $1500, you yet will have a FR driver and no xover and these planars are much more detailed than a speaker.
My favor could be the Arya $1600
https://store.hifiman.com/index.php/headphones.html

[FreedomJazzDance]

Thanks for all the advices about this topic, but this days I made the conclusion that in a long way, 3 way loudspeakers will better fit my needs, Already purchased the first drivers for it, it's also a design by Fostex, will create a thread about it soon, thanks everybody, great Forum, very and many thanks for the FullRangeMan for introduce me this amazing Forum, I'm sure that I will learn a lot here, I hope that on the way I also can be able to help people when I acquire more experience

[FullRangeMan]

In that xover area I would suggest you a 2way, Bass Reflex, hi sensitivity 100dB,15 inches woofer only $220 each and a OB FR driver that will allow you use a tube amp:
https://www.eminence.com/speakers/speaker-detail/?model=Kappalite_3015