SMALL horn bookshelf ?

[Steven-H]

All,
I recall somewhere seeing a small folded horn bookshelf. It looked to use a 4-6" driver. Judging off of that, it seemed to be about 12" high, by 8" wide, by perhaps 16" deep. Anyone ? Would there be a benefit of a small horn over a bass reflex design ? Sorry, but I am obviously a FR noob.
I'm currently building a low powered (4-6w) SE amp for my bedroom, and space is a premium (The amp itself is going to fit inside a jewelry box). All I am after would be response down to 65hz or so; as I have a feeling the tiny OPT's I am using roll off below 55hz anyway.

Thanks !
Steve

 

[Scottmoose]

You wouldn't be thinking of this would you?

http://www.haut-parleur.net/ct193.html

 

[sreten]

http://www.troelsgravesen.dk/FE126E.htm

Hi, one option, /sreten.

 

[Steven-H]

Gents,
Thanks for the help - Sreten, those bookshelves sure look tempting; 94db would be an excellent match for the amp and room size.
Anyone else ?
I was looking at planet 10's fronken box. Im sure it would be an excellent match as well; but I don't have a table saw, etc. So that kinda puts it out of the running.

Thanks !
Steve

 

[AdamThorne]

Makizou

http://www.diyaudio.com/forums/showthread.php?s=&threadid=81133&highlight=

 

[Steven-H]

Adam,
Ahh - that is awesome ! Shame there isn't more info on the net - but I did find the plans on this site...Might be a winner !

Thanks to all,
Steve

 

[planet10]

You wouldn't be thinking of this would you?

http://www.haut-parleur.net/ct193.html

A miniBVR

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

dave

 

[planet10]

Anything that small isn't really going to be a horn, but a TL variation... doesn't really matter as long as it works....

I have a set of BK101s on my test bencg that work wonderfully... (no tweeter used anymore)

original plans attached

dave

 

[planet10]

my rework of the drawing (it was a long time ago - it is a bit skimpy.

 

[planet10]

And a picture of the insides of someone elses

 

[Godzilla]

It cracked me up to see that old box lying on that even older persian rug. Both the box - now painted with blackish fleckstone and still playing at uncle Elis appartment, and the rug exist.

When i built it i think i estimated the spacing between panels.

The speakers actually make music with a RS 1197. Great sound for the $$$ but still best with a sub IMO. Today if i decided to build them again id use pine rather than mdf.

Thanks,
Godzilla

 

[planet10]

Sreten, those bookshelves sure look tempting; 94db would be an excellent match for the amp and room size.

94 dB is probably a bit optimistic. Factory on the driver is 93 dB, and the average of 40 units i've actually measured is about a 1/2 dB less than that. The 126 really doesn't work all that well in a BR, an FE127 is a better bet here.

dave

 

[planet10]

I was looking at planet 10's fronken box. Im sure it would be an excellent match as well; but I don't have a table saw, etc. So that kinda puts it out of the running.

Have you checked the box plans recently? 3 easier to build variations of the Fonken are now up (2 of them floorstanding). I haven't done a simple BR based on the Fonken tuning but Rabbitz BR is probably close to what that would look like.

dave

 

[Steven-H]

And a picture of the insides of someone elses

Dave- Thanks a bunch; my hat is off to you Sir !

Any idea on the width dim of the modified plans ? What driver would you recommend with this ? 126/166 ?

Thanks !

 

[Scottmoose]

I don't think Dave modified them -he just re-drew the originals for clarity.

Here's another relatively small box -I just re-discovered this design amongst my archived collection on an old HDD.

 

[sreten]

94 dB is probably a bit optimistic. Factory on the driver is 93 dB, and the average
of 40 units i've actually measured is about a 1/2 dB less than that.
dave

The apparent 93-94 dB sensitivity cannot be achieved in a small vented construction. It would be much too bright.
Thus the overall response is tuned for a ~89 dB sensitivity, but this is not bad at all for a mini.
Many similar constructions may only reach 80 dB/2.8V/1m.

The 126 really doesn't work all that well in a BR.......

dave

I've tried cross-calculation on the Fostex data (right) and something juts doesn't fit.
Cross-calculation on own data looks fine, but Mms is significantly higher and Qt
fortunately much higher, making a vented cabinet more appropriate.

/sreten.

 

[planet10]

Any idea on the width dim of the modified plans ? What driver would you recommend with this ? 126/166 ?

As Scott said, my drawing was for clarity, we followed the original (internal width = 173mm) ... This is designed for the FE103, I'm used FE103A (which required a supraBaffle after we tried to install the driver and found the extra deep magnet wouldn't alow the flange to meet the baffle), and Jeff used the Radio Shack 40-1197.

dave

 

[planet10]

Here's another relatively small box -I just re-discovered this design amongst my archived collection on an old HDD.

I did a bit of image processing on the map to make it more useful. Do you know the intended driver?

dave

 

[Scottmoose]

Yes, it was designed for the original FE108Sigma, so from the specifications, the new 108ESigma should be a decent enough replacement. The cabinet is a Nagaoka design, the D-10 I believe.

 

[Steven-H]

Gents,
Thanks again for all of the help ! I will have to see if I can track down a 108e. Dave ?

Thanks !
Steve