open baffle fullrange for my little nephew

[Calamaro]

I want to build some simple open baffle speakers for my little nephew (7 yo and listen to brit rock)

No much room, so today I bought two narrow wood panels (100 cm x 20 cm).

About the drivers I have 2 choices, both vintage drivers with alnico magnet:

• some tiny (10 cm), maybe from an old compact radiorecorder;
• some bigger Telefunken (15 cm x 23 cm).

I think baffle is too narrow for Telefunken, can I use a folded shape or a H shape? H shape should be good because of better stability.
Or is it better to use smaller drivers?

Amp is a Tripath TA2024.

Thank you for your opinions.

[steviedon]

I'd say look for a high qts driver with some semblance of a flat curve above 80hz and decent x-max. Scratch that tiny driver from the vintage radio. The telefunken may work but likely has a very high Fs, so scratch that too. Some candidates.....
1. Tang Band W3-1364SA 3" Bamboo Cone Driver | Parts-Express.com
2. Tang Band W3-881SJ 3" Shielded Neodymium Driver | Parts-Express.com
3. Vifa NE95W-04 3" Full Range Woofer | Parts-Express.com
4. Vifa TG9FD-10-04 3-1/2" Glass Fiber Cone Full Range | Parts-Express.com
5. https://www.madisound.com/store/prod...oducts_id=8860
6. https://www.madisound.com/store/prod...oducts_id=8817

What I've listed here is relatively affordable.....all in the 3-5 inch range since you have space constraints. Later down the road when the neph gets an itch for some low end you could fill it with a frugal diy sub.

[Calamaro]

Hi Steviedon, thank you for your great help.
May I ask you why high Fs is a no-no for OB?

[steviedon]

Any driver in OB ( as my very limited experience would reveal) is either going to unload or produce 0 sound below Fs......both ugly for sound......unless you source a suitable driver w/ a low( sub 100hz) Fs in the 3-5inch range. If you hit a wall follow up and I'll post more links.

[mashaffer]

Goldwood GW-8003/8 8" Full Range Driver w/Whizzer | Parts-Express.com

Inexpensive (good for 7 yo). High end is not as smooth and extended as some but the Q is better for your application that a lot of them are. I would not use H baffle for full range. Some wings going back a few inches would be good though.

Also If you can get the driver close to the floor and angled back it can help the low end. Adding a cheap sub and or Piezo helper tweeter would be easy if needed.

Unlike a box speaker I don't think going with a smaller driver helps much (at all?) with space constraints as the baffle width for reasonable roll off will be the limiting factor and the larger driver will move more air.

[chris661]

Originally Posted by steviedon

Any driver in OB ( as my very limited experience would reveal) is either going to unload or produce 0 sound below Fs......both ugly for sound......unless you source a suitable driver w/ a low( sub 100hz) Fs in the 3-5inch range. If you hit a wall follow up and I'll post more links.

I'm struggling to understand why it won't produce sound below Fs. Bass response from an OB is governed almost entirely by the baffle dimensions. Large baffle = lower roll off. Small baffle = higher roll off. Provided the speaker is moving, there will always be output, though it might need eq to come in line with the rest of the frequency response.

Here's a thought. Pick a 3" wide band driver, an get a cheap 6.5" midbass to come in lower down (maybe 150Hz). If it had significantly higher efficiency, you could put a 6dB/octave low pass filter on, to effectively eq a little more bass in.

Chris

[owen]

Hi,
Both vintage drivers are likely to be just fine - the telefunken more so, and I would make a U shaped enclosure for them - it will be lots closer to the radio that they originally came from. Dont be suprised if you need a helper tweeter, or a few minor mods... But build it first and see what it sounds like, you may well be suprised

Have fun


Owen

[steviedon]

I could be much more help if I knew exactly what size footprint is available, and what an acceptable height would be. Also, are you dead set on going OB with this project? If I myself wanted build something respectable on a very small footprint I'd very likely opt for the pencil 70 and use the $30 Mark Audio CHR-70.
http://www.markaudio.com/sites/all/f...-pensil-70.pdf

[Bigun]

The Pencil looks nice, but perhaps a 7 yr old is going to be using it for pin bowling - tall and skinny and easy to knock over.

maybe try this:

Gainphile: S11 OB - Bookshelf open baffle with Seas 8" and Tangband Full-range

[Calamaro]

Thanks for all your suggestions.
As I have several spare vintage drivers (some nice Philips too) I would prefer to use them in this cheap project. That's a way to learning new things too.
Re OB, at the moment this is the kind of sound that I prefer.