Aperiodic Enclousure

[Holty]

Originally posted by lovechild
Hi Jim,

you might want to look at Martin J. Kings ML TLs here, just look in the "Projects" section.

There's a Project for the Fostex FE-208 Sigma that, I think, could easily be addapted for your driver. Maybe you even find a nice fellow here in the forum who is willing to modell your Fostex' in a MLTL with MJKs worksheets. I would do, but my PC died recently and the software won't run on Mac...

best, LC

That is close but it looks as though this driver is going to be just to big for my room. The cabinet needs to be no more than 10 inches wide overall or it will look overpowering and get in the way. The speakers will be either side of a chimney breast and one near a door also. The height and depth are ok. Its a pity as this driver has everything like the whizzer, radial cone, cast frame. Don't think any other Fostex does all this or is their a smaller one to compare to the 206ES-R. Thanks Jim.

[lovechild]

Originally posted by planet10

.. am Intel mac will come soo thou.

Yup, that's the way to go! Just waiting for some money

@Jim
I woud think it's possible to fit the 206ES-R in a width<=10" enclosure, it's max external dimension is 9", don't know if it will look nice thou...

LC

[Corloc]

Is your heart set on the 206ES-R? If not the Visaton B200 may work for you. I believe Scott Moose came up with the dimension I about to give. 38" tall, 9" wide, 12" deep, driver set 8" down, stuff cab with .5lbs ft^3 of dacron. and use two scan speak aperiodic vents on back. These are internal dimensions. Look up B200 and aperiodic on the lists.

E-speakers sells the B200 for 135.00 ea? you could buy them and build cabs for less than the cost of 206ES-R's.

Chris

[Scottmoose]

B200 = best with Dave's phase plugs. The Scan Speak vents are nice & look good. DIY versions if anythign are better. Either drill a load of holes in the cab & damp internally, or route a slot in it and stuff with reticulate open-cell foam. You can't really chop to top couple of feet off Abby and have the same response. Having said that, Abby internally isn't all it seems to be externally.

OK, OK. I don't like to see people struggling, and you seem to have your heart set on the 206ES-R. And why not? It's a stunning unit, so I hear. Give me a few minutes & I'll see what I can come up with. We're looking at an external width of 10in, max, right? Not an insurmountable problem by any means.

[Scottmoose]

1 quick MLTL for the Fostex FE206ES-R. All dimensions internal. Nice & simple build too.

46.5in x. 8.5in x 12in (height x width x depth). Driver centre 9.5in down from the internal top. 3in diampeter x 2in long vent on either the front or rear panel (I'd suggest the front in your case), centre of the vent 2in up from the internal base. Stuff 0.25lbs ft^3 of hollow-fibre damping material from the top 26in down. 3ohms of series resistance added to smooth the response out. I've kept a moderate roll-off in the FR to account for room-gain. If you want to completely flatten the response (flat = not a great idea as the room is going to lift the bass well above this) then boost this resistor value to 7ohms.

Baffle step circuit will need roughly a 3ohm resistor paralleled with a 1mH inductor in the hot lead. Optional (but useful) zobel = 8.5ohm resistor in series with a 2.75hF cap across the terminals, or the nearest you can find to this value.

I'd advise doubling the top panel, as this is the point of maximum pressure in an MLTL and you don't want it singing away with the music. A nice 1in roundover would be a good plan too.

If you find this too tall, reduce internal height to 40.5in, all other dimensions remain identical, so the positions of the driver and the vent relative to the line stay the same: 9.5in down and 2in up respectively from the internal top and bottom. The price is Fc shifts 4Hz higher. I like the tall box myself.

[Holty]

Thanks Scott for the info. It would have to be the smaller one as the wife doesn't want them any higher than a metre. I had got my heart set on that driver but do you think its a bit of overkill for my room which is roughly 13' x12' ? Do you think the FE168EZ would be a better unit? As for getting balance and the room accoustics right i have a room correction device to help with that.

This is all new to me so excuse me for being a bit thick as regards to full range. I am used to two way speakers and just wondering if these would be an improvement on them.

[Scottmoose]

In your room, frankly, I'd use something smaller as an 8in driver will over-load it -that's not a big space. 13ft x 12ft is ripe for a Frugalhorn, A126 or a Metronome: see www.frugalhorn.com If you find the first two a bit tricky to build, the latter is very easy, and has extremely high WAF -that's what it was designed for. The 4 1/2in drivers are what you want in that room. They're much better at the top end and in the mid-band than any of the larger units, and will match your room well. The FE126E in particular is an astonishing unit for the money. Another interesting idea would be Mileva using it's higher Q stablemate, the FE127E: see below. IMO, the FE108ESigma, though a wonderful driver, really needs to be put into a much larger horn than you have space for. Plenty of options available.

Don't think these drivers are poor cousins of the larger & more expensive units -as I say, in some ways, they actually beat them.