Good compact enclosure for FE166en to survive student life?

[monty78pig]

Hi Everyone,

I'm planning on building a pair of bookshelf speakers with Fostex FE166en drivers as they are fairly easy to get hold of and also quite efficient (my amp is only 10 watts). General consensus also seems to dictate that they are the best in the FE range .

However looking at the recommended enclosures on the datasheet the bass reflex enclosure is 45cm tall which isn't exactly small. Is there any way to make it a little shorter, would using a passive radiator instead of a reflex port help?

I'm an absolute n00b when it comes to loudspeaker design so don't hate .

 

[Bob Brines]

IMO the wrong driver for a bass reflex bookshelf speaker. If you like the Fostex sound, the FF165WK would be a better choice.

Bob

 

[monty78pig]

Ah, OK. Why is it not good for a bass reflex speaker? What sort of enclosure would you use?

 

[xrk971]

It is a very low Qts and has limited xmax - so would be best used in a back loaded horn to extract the bass and control cone motion. The Fostex literature recommends a 15L enclosure for a bass reflex and it only tuned down to 65Hz.

An externally hosted image should be here but it was not working when we last tested it.

A BLH on the other hand will go deeper but be big.

 

[Bob Brines]

Following up of xrk, no bass and you will have to do something about the rising response. In a BR the FE166En will sound thin and very hot on top. This driver was designed for a back horn, The FF165WK was designed for bass reflex.

Bob

 

[monty78pig]

I see, at a glance the frequency response of the FF165WK drops off quite heavily past 10KHz, could I add a tweeter to compensate for this?

It would of course necessitate an extra amplifier and active crossover though.

Are there any other 6" full range drivers that would be good for this application?

I'm learning... Slowly

 

[Scottmoose]

Yes, of course you can add a tweeter if you wish. Whether you feel the need is another question -you may find yourself happy as-is, although I'd prefer to use it with LF support.

Adding a tweeter does not require an additional amplifier and an active crossover. You can simply use a passive crossover, which may, depending on implementation, be as simple as a single capacitor and a padding resistor.

Fostex's En series units (from the 126 upward anyway) were designed primarily with an eye to their being used in back-horns with high output impedance amplification, or correction to provide similar results.

As for other units in roughly that size bracket, Tang Band, Mark Audio, Dayton, Supravox, Audio Nirvana and even Vifa (there are others too) have one or several units you may wish to look at. Depends how much you want to spend.

 

[freddi]

It was used in the Karlsonator 6 prototype - I didn't get to hear it as the driver got ruined in a basement flood. Put grill cloth on it for protection

a large plan can be downloaded at the following link under "More"
https://plus.google.com/u/0/photos/...5900892856466880930&oid=100545049816297868412

 

[monty78pig]

Thanks for the great advice guys, I've now got my eye on the Markaudio Alpair-10P, as well as the FF165WK but I'm a little peturbed by what happens to it's frequency response post 10KHz.

I've done a bit more research - can someone tell me whether this is a good idea? https://www.madisoundspeakerstore.com/pdf/markaudio-enclosure-plans/Alpair10-BR-cover.pdf

I don't have much woodworking experience so would prefer to go with a simple bass reflex, or a double chambered bass reflex type enclosure, the Karlsonator looks good, but it's a little too complex for me and also a little too big. I'm really looking for something I can put on the windowsills in front of my desk about a metre or so away from me.

Fostex's En series units (from the 126 upward anyway) were designed primarily with an eye to their being used in back-horns with high output impedance amplification, or correction to provide similar results.

So single ended valve amplifiers?

Also in regards to protective grills are aluminium mesh types a no-go?

I'm really looking for something simple, with fairly good efficiency (90dB @ 1W or so) that won't be too bulky .

 

[freddi]

if not already purchased, then an Alpair should be a consideration - I've not yet owned one but they're highly regarded

 

[Scottmoose]

Thanks for the great advice guys, I've now got my eye on the Markaudio Alpair-10P, as well as the FF165WK but I'm a little peturbed by what happens to it's frequency response post 10KHz.

Not many complaints to date but YMMV. No large widebander has a particularly pretty amplitude response vis-à-vis a well-designed multiway, but this is not typically a priority for the people who use them.

I've done a bit more research - can someone tell me whether this is a good idea? https://www.madisoundspeakerstore.com/pdf/markaudio-enclosure-plans/Alpair10-BR-cover.pdf

The alignment's fine with the 10P.

So single ended valve amplifiers?

Do some things very well, some things less so, but depends. There are single ended amplifiers and there are single ended amplifiers. A 0.5w job using TV sweep tubes does not have the same set of compromises as a 40w monster using 211s, GM70s or similar.

Also in regards to protective grills are aluminium mesh types a no-go?

Providing they're sufficiently open, not a big issue. Besides, you can always remove them.

 

[GM]

Also in regards to protective grills are aluminium mesh types a no-go?

If you choose a driver with a 'hot' rising on axis HF, I've had good luck using a tightly stretched fine metal mesh, pet screen or even true vintage grill cloth ['40s - '50s era] to dissipate it as well as making it mostly 'toga party' compliant.

GM

 

[monty78pig]

OK, so I've now decided on the Markaudio Alpair-10P-A, but can't seem to find an enclosure plan for them, they are quite similar to the 10As which have a bass reflex enclosure plan but the Qms, Qes, and Qts values are different.

Qms is 2.425 for the 10Ps but 1.930 for the 10As
Qes is practically the same, only off by 0.06
The Qts difference is about 0.16 or so

Does this make a big difference, can I use them in the enclosure's for the 10As?

There are two different enclosures for the Alpair 10 series on the Madisound site, one is tuned to 47Hz and the other to 43Hz.

Sorry if I'm being a little slow but I don't really know any of the maths behind loudspeaker design . Does anyone know of any good resources or is it one of those things you learn from experience?

 

[planet10]

The best enclosures for FE166En are Austin A166, Haruna, Victorm and maybe Frugel-Horn XL. All are horns & even the smallest is not small. In an optimum bass reflex FE166 likely does not even reach down to 100Hz.

I have lived with FE166 (in Victor). FF165wk in the Fonken166 Compact Floorstander, and the Alpair 10p in Frugel-Horn XL. All are good but my personal preference is last to 1st.

FF165wk & Alpait 10p fit in about the same size bass Reflex. You could go as low as 10 litres probably, optimum is 16-17 litre, and max is on the order of 10 litre. If HF is a woory the Alpair 10.3 has a bit more top than the A10p, goes in a smaller box, but gives up 3 dB.

Don't put too much into the FR plots. They can be helpful but are far from the whole story.

dave

 

[planet10]

Alpair-10P-A, but can't seem to find an enclosure plan for them, they are quite similar to the 10As

The A stands for Arrestor. All current Alpairs have them. These 2 drivers are A10p (paper) and A10.3 (metal). They do not fit into exactly the same box.

There are quite a few enclosures extant for A10p.

A simple reflec is pretty easy.... how big would you like it? There is a thread where scottmoose presents 16 litre (?) enclosures for each.

http://www.diyaudio.com/forums/markaudio/250751-bass-reflex-standmounts-10-3-10p.html

dave

 

[monty78pig]

Thanks for the links, definitely building these now! The 16L is a little big but is it necessary for better LF response? Would a lower volume design with a smaller port be an issue?

Also what software did Scott use to model this?

 

[Greg B]

Very very roughly: a slightly larger reflex enclosure volume tends to lead to a loose and flabby but more extended bass, while a smaller volume push the sound towards bouncier and perhaps more colored bass.

I'm currently using the 10.3M in 16l Golden Ratio boxes. In this case, the driver is well controlled enough that the larger volume sounds subjectively transparent and open, rather than flabby.

If you listen to more pop and rock than jazz and folk, you might prefer the smaller volume.

Anyhow, I think you'd be happy with the Alpair 10, as long as you don't try to use them as crazy party speakers.

 

[monty78pig]

Ah OK. I listen mainly to Jazz type stuff and older rock, but not at insane volumes. How high can you push the volume control before they start to get muddy?

I plan on using them with an amp with very low output impedance so I'm guessing the larger volume is for me. How much padding would I have to use? I prefer a tighter sound TBH.

I remember reading somewhere that a smaller enclosure with a smaller port, as is shown on Madisound (I finally found the recommended enclosure) creates more port noise and distortion than a larger one?

I won't be using these for anything ridiculous, I just want a good neutral pair of fullrange speakers that I can use for doing my shellac restorations with.

As far as distortion goes is there any difference between the paper and metal? The frequency response of the metal drivers gets a little high towards the high end but I'm guessing a thin cloth grill would reduce this?

 

[Greg B]

It was used in the Karlsonator 6 prototype - I didn't get to hear it as the driver got ruined in a basement flood. Put grill cloth on it for protection

Too bad about that flood.

Obviously I'm a bit biased, but the Karlsonator 6 is about the smallest practical design for the FE166 that addresses the bass limitations and rising response. I found my initial kluged sims recently if anyone is interested. (xrk's model will be more accurate) I believe it would get to about 55-60 with fairly flat overall freq response.

 

[Greg B]

Ah OK. I listen mainly to Jazz type stuff and older rock, but not at insane volumes. How high can you push the volume control before they start to get muddy?

I plan on using them with an amp with very low output impedance so I'm guessing the larger volume is for me. How much padding would I have to use? I prefer a tighter sound TBH.

I remember reading somewhere that a smaller enclosure with a smaller port, as is shown on Madisound (I finally found the recommended enclosure) creates more port noise and distortion than a larger one?

I won't be using these for anything ridiculous, I just want a good neutral pair of fullrange speakers that I can use for doing my shellac restorations with.

As far as distortion goes is there any difference between the paper and metal? The frequency response of the metal drivers gets a little high towards the high end but I'm guessing a thin cloth grill would reduce this?

The 10.3M have a rather uncanny knack for not breaking up when cranked up fairly loud (compared to other small speakers). They basically don't get muddy. Can't speak for the 10p. I've noticed this quality before in metal cone speakers.

Subjectively, they are actually on the mellow and laid back side to my ears. I seriously doubt you will find them too bright.