good cheap first project ideas

[johninCR]

For something small for one of the little Fostex, you might want to try one of Takenaka's spiral horn designs at http://www3.ocn.ne.jp/~hanbei/eng-intro.html
It's some kind of BR horn hybrid and he reports getting bass extension into the 30's with small high Fs drivers. Making the spiral might prove a little tricky, but the rest of the construction is straight forward.

I'm going to try the one for the Fostex FE206's when my drivers arrive. I plan to make the spiral using popsicle sticks on a treaded rod with fiberglass and epoxy for strength. I'll also use a normal PVC pipe instead of what appears to be thicker higher pressure tubing which seems like overkill to me.

[planet10]

Originally posted by saramac
I would like to build some bookshelf speakers. I have an older 20w sony micro system of decent quality but the speakers [a ported 2-way] are awfull. Something say 12" square or there abouts. Ported so as to have some bass extension. Single full range drivers always sound so nice. Cheap is good here.

You've got a lot of really good suggestions already... what you get will depend somewhat on budget as well. The CSS WR125 is very nice (in the limited listening i've had), the FE127, FE107, & FE103 are standouts in their price range, i have an Adire AV3 project (bipolar alphaTL) waiting to be assembled, also consider the Radio Shack 40-1197 if you can find a Radio Shack with some stashed in a dark corner, or find someone willing to part with a couple. As Tim & Terry demonstarted amply at the recent NW-DIY-fest and GM in Atlanta, these budget versions of the FE103 can make a remarkable speaker (and if your out looking for RS drivers the 40-1354 is no slouch either).

This FE103 box is a winner on looks alone... http://home.hetnet.nl/~geenius/Solo103.html

dave

[ScottG]

The problem here is off-axis response, most fullrange drivers with any bass will have little treble off-axis.

The solution is a GOOD coaxial driver.
Seas T17RE
Its not cheap, but it isn't expensive either considering that your getting a GOOD midbass driver and a GOOD tweeter.

If you can cope with the loss of treble off-axis then the Fostex FE 167E should be good. If you can do w/out the bass then consider the Fostex FE 103E.

All are available from Madisound.

[morbo]

why not just build a small TB 871 based speaker? They are cheap, have fairly wide range, and if placed on a bookshelf they would probably gain some bass.

[planet10]

Originally posted by morbo
why not just build a small TB 871 based speaker?

I was going to mention mark mcKenzies 881, but these & the 871 are quite bass-shy.

dave

[dvdwmth]

Based on what he mentions at the start of the thread I think the lack of bass on the TB might be a problem. I have a friend that wanted a small bookshelf and he didn't like my w3871s by themselves.

Don't get me wrong, I love them. In fact they are my main speakers but they are crossed to a 12 in and I don't really like them without the bass driver.

[Timn8ter]

I like the 871 in a small BR for very near-field listening (they are my PC speakers) but I wouldn't use them by themselves in a room.

[indoubt]

Visaton FR10 4ohm, 20w rms, in a 2,9 liter cabinet (20cm high, 20 cm deep, 11,8 cm wide) 2 br pipes, 16mm internal dia 70mm long.

Plays down to about 65Hz, currently powered by a blaupunkt car radio at the office.

Ammazingly cheap, the speakers come at approx 7 euro's a piece and they go further down than most TB's in this size box. They are not filtered but if you play without a simple equalizer a simple notch filter might be required

[johninCR]

I don't know. That FR10 response reminds me too much of the 49 cent NSBs with that break peak in response. The Visaton just goes a bit lower.

Of the Visatons, I like the FRS8 much more with its linear response. http://www.visaton.de/english/artikel/art_261_1_3.html

I wish those were 49 cents at PE. I'd buy at least 1,000 . Who cares if they're only 82db/1w/1m ? They'd make perfect 32 driver floor to ceiling dipole line arrays.

[dvdwmth]

where do you buy visaton in north america? Only place I can find is solen and they dont have that one.