Efficient Bookshelf?

[Whit]

I'm trying to find either a kit or plans for a somewhat efficient bookshelf, but so far I haven't had much luck. I am looking for around 87db/w/m. I would really appreciate any recomendations. Thanks.


Whit

[joe carrow]

1) How large is too large?
2) What kind of material do you listen to- do you need extremely low bass?
3) Do you listen at a high SPL?
4) What kind of amp will you use- solid state, or tube? Specifically, is it OK for 4 ohm loads?

These are important questions for coming up with a good project. My bookshelf might be larger than your bookshelf, you know?

Just guessing, but I think that something on the large side with a paper woofer is what's going to do it for you. I'll look around a bit if you don't mind answering my questions.

[davidallancole]

http://www.parts-express.com/project.../homeaudio.cfm

[Whit]

Hi Joe,

1) I'd like them to be 14hx9wx13d or smaller if possible.

2) I mainly listen to jazz and classical so I don't need extremely low bass.

3) No, I like around 70-75db.

4) It will be a solid state class-D amp. 4 ohm loads are ok.

[planet10]

Originally posted by Whit
1) I'd like them to be 14hx9wx13d or smaller if possible.

2) I mainly listen to jazz and classical so I don't need extremely low bass.

3) No, I like around 70-75db.

4) It will be a solid state class-D amp. 4 ohm loads are ok.

Fonkens. 91-92 dB, 14 x 8 5/8 x 11 3/4.



1st entry on the Fostex box-plan library page

http://www.planet10-hifi.com/boxes-fostex.html

I'm predudiced but think they really are stunning. I listen mostly to jazz with classical taking a big up-tick recently. These seem to work well with Class D amps.

dave

[joe carrow]

I still haven't purchased a small full-range driver to see what that's all about, although a lot of people like them. Still, I'm not sold on the idea.

According to models based on excursion, I have a fairly good idea of when my present speakers ought to start sounding horrible. Sure enough, if I feed them some loud bass they do start to freak out as predicted. With a small driver with low Xmax, I can't help but think that without some major horn loading there would be a major limitation in dynamics and bass. Give them bass bins and I might be on board.

I do agree with the part about Class-D amps, though. This kind of driver has often been said to work best with tube amps. Tube amps have a higher output impedance than solid state, something they share in common with Class-D.

With and classical, I kind of like the shallow roll-off of a sealed enclosure. Sure I'm not getting the deep notes, but the way the response tapers off sort of leaves them to my imagination and doesn't sound as unnatural as a ported box that's overdoes the bass. Extended bass shelf tunings sound nice to my ears.

I don't know of any good projects right now, but I'll keep my eyes out.

[planet10]

Originally posted by joe carrow
I still haven't purchased a small full-range driver to see what that's all about, although a lot of people like them. Still, I'm not sold on the idea.

You need to hear a set of these then

With and classical, I kind of like the shallow roll-off of a sealed enclosure. Sure I'm not getting the deep notes, but the way the response tapers off sort of leaves them to my imagination and doesn't sound as unnatural as a ported box that's overdoes the bass.

The Fonken is designed to be more like an aperiodic box than a ported box. The bass they do produce (est 65-70 Hz) is well defined and nice. I've not been able to drive them over the edge with any of the amps i have... even when used in HT with mains set to large.

dave

[joe carrow]

For the entry price of $36.50 at Madisound, I'm intrigued. I already have an 0.38 cu ft enclosure from Parts Express. If I had an FE127 in this box with an aperiodic port, do you suppose I'd get the general idea of what's nice about these single driver speakers?

[planet10]

You would get the general idea. The rough edges on the drivers get smoothed over with driver mods. You'd have to shrink your box a bit -- but these MDF boxes really need some serious bracing anyway.

These ones?

http://www.partsexpress.com/pe/showd...number=302-710

If it were a tiny bit taller it could be made into a foldeed diyAudio FR Ref ML-TL... it should be big enuff to squeeze a Fonken-ish design into.

dave

[planet10]

[QUOTE]Originally posted by joe carrow
with an aperiodic port/QUOTE]

The porting is a bit trickier than that, to get decent bass it need sto be nearly aperiodic. This is achieved by using a very high width to height ratio on a long port (i think i calced it at something like 50:1.

dave