A Pioneer B20 Enclosure...

[shloky]

Hey all,

Gearing up for my first DIY speaker project. Just wanted to make sure I'm not zooming off in the wrong direction:

Amp:

• Basic Sonic T-Amp - which I may recase and modify if I can figure it out

Driver:

• Pioneer B20
• PE Tweeter (Maybe the 1.50 piezo)

Wood:

• Birch Plywood

The Challenge:

• I need a shorter enclosure due to transportation problems - I can't do the BiB and would rather stay away from the 5ft Chang until I settle down somewhere.

After much searching I have come across the following enclosure types:

• Nelson Pass' model
• GM's Model
• Fast1One Model

Any advice on which design to follow would be great.

Thanks,
SV

[Godzilla]

Hi, if you want to build a smaller simple ported cabinet you can also look at:

http://www.zillaspeak.com/pioneerb20-3cubox.asp

If you tell me your ideal size for the speaker i can simulate a proper box for you using WinISD. Nothing fancy, just a box with a hole. Sometimes simple is better. I don't know how the more elaborate boxes sound with this driver.

The Sonic Impact amp (standard $30 version) works really great with the B20. I use that combination every day at work.

http://www.zillaspeak.com/pioneerb20-piezo.asp

Sealed boxes don't maximize bass response of the B20 but the sound is clean and clear in sealed boxes from .75 to 1.3 cubic feet.

Peace,
Godzilla

[gychang]

Originally posted by shloky
Hey all,

Gearing up for my first DIY speaker project. Just wanted to make sure I'm not zooming off in the wrong direction:

Amp:

• Basic Sonic T-Amp - which I may recase and modify if I can figure it out

Driver:

• Pioneer B20
• PE Tweeter (Maybe the 1.50 piezo)

Any advice on which design to follow would be great.

Thanks,
SV

I have used piezo and this http://www.partsexpress.com/pe/showd...number=275-025 dome with B20, and dome is much better.

gychang

[davidallancole]

Godzilla, whats the -3dB on your closed boxes?

Would it be worth using a good solid state amp with a ~3-3.5 ohm resistor in series with the positive lead? This would effectively raise the total Q of the driver and doing sims in WinISD shows that with 3.5 ohms in series, you could get a cut off of 44.28 Hz. Thats with a box size of ~ 30 cu ft. Reducing the size to 3.5 cu ft (0.84 for a Qtc) has a cut off of 45.51 Hz. This looks better than the Qtc of 0.7 with no resistance in series having a cut off of 59.8 Hz.

Just a thought. I don't know if it would actually work in practice.

[shloky]

Zilla - Appreciate the response, your posts are why I decided on this driver. I guess I'll wait until round two for the complicated stuff.

Something around 48'' vented would be great - I know you've built a 42'' sealed - and the lady would like thin (but if thats not doable I'll wow her with the quality right?).

I've been trying to model custom box sizes in WinISD with little to no success, so again, I appreciate the help.

gychang - Added the dome to the shopping list. Just picked up a Sonic T-Amp for $22 from Buy.com with the Google Checkout discount. Excited about the new possibilities.

Thanks,
SV

[gychang]

Originally posted by shloky
Added the dome to the shopping list. Excited about the new possibilities.

Thanks,
SV

need to get the opening exactly 1.25" and slipps right in. let us know your impression of the sound.

gychang

[3-LockBox]

I have intentions of building bipoles using the B20s in a 2.2 cu ft enclosure with a 12 passive radiator. I have a 2.2 cu ft enclosure already but may build a larger one, say around 3 cu.ft.

By some accounts, the enclosure requirement can be halved if the PR area is equal to or greater than the surface area of the active driver/s.

I've done the bipole/PR thing with smaller drivers and got stunning results.