Best woofer for Open Baffles

[Moondog55]

I have been experimenting lately with OB speakers, just for fun and using the cheapest drivers around ( Astralian dollars $20 each or less ) I am pleasantly surprised.

If wanting to build with out using EQ what would be the best OB woofer??

I would prefer to buy locally but know that in all probability I'll need to import, found these when doing my search

http://www.partsexpress.com/pe/showd...number=290-346

Baffle size maximum ( WAF ) would be 750mm but I can go 1650 tall or even a little taller.

These don't need to go too loud, 105dB is more than adequate as average SPL would be around 89-91, and I was thinking 4 woofers in series parallel for nominal 8 Ohm load.
Current experiment is using 4 of the Jaycar close-outs 2 X 10 inch and 2 X 12 inch , no baffle as yet just a blanket on the floor.

Regards
Ted

[badman]

Check out the lambda dipole drivers from www.aespeakers.com. There aren't specs on the 'main' site pages for the 'dipole' drivers, but they're readily available with some searching

[Moondog55]

Thanx I found the IB 15, seriously good spec's but nil drivers with Qts over 0.9, do you have a link for me.
From my limited reading I was under the impression that a driver "Q" of between 0.95 and 1.1 was best in OB, and everhing else being equal the lower the resonance the better I'd like the sound ( organ music and Taiko drums )

[hitsware]

http://www.partsexpress.com/pe/showd...number=290-345

[PeteMcK]

2 of these/side: http://www.cannononline.com.au/p/577...frequency.html

[fwater]

I was inspired at the low cost of a Goldwood 8" fullrange paired with the 40oz. 15" woof that someone had posted a while back. The free shipping recently got me to purchase the 8" drivers, but I held off on the woofers to do some modelling. The pro version of the 15" models O.K., the 40oz. version is just a bit down in sensitivity, and the super high Q regular 15" looks like it goes lowest (due to 1.95 Qts.?). All three should get you 105dB in room at 40Hz with modest power, falling off quickly after that.

The Alpha 15" is very dear to many and reported to be a great performer if you can spend a little extra.

The Dayton IB385-8 has plenty of X-max for still more $, but sensitivity is a little down.

OB is addictive; jump in.

[Moondog55]

Badman I found the OB 15, if it was avaliable I might be able to fund 2/ 4 of those, US peso is headed back North I see so more and more expensive each day, from their forum not avaliable at this time.
Peter the Q is a little lower than I thought was best fit for OB use, price is on the money tho.
If only Parts Express would do surface shipping so I don't have to pay for two lots of postage,
The wife is headed for the States in a month for birth of first grandchild :"BOY will she have a BIG shopping list"

[gainphile]

I'm really happy with the performance and build quality of the Alpha 15s. However when equalised heavily they still can bottom out thus another pair which is still laying around the moment

This is taken 1m from the source, equalised at LF and no lowpass filters so you can see the breakup at 2kHz (as specified in datasheet). Very decent flatness to the extreme lows.... It was measured in a small room so please excuse the peaks and valleys.



I played ES Posthumus song and my mate can't believe that bass notes can go that deep... and pure

I had previously looked at DJCity stuff, which are quite cheap .. $65 and $75 but after holding them was putoff by the build quality. It would be interesting if they sound good though.

http://www.djcity.com.au/product_vie...mIMAGE=B15-200

[Saurav]

How high do you need it to go? I believe I have the first pair of AE OB12s, and I like them a lot. On my 14" baffle, they definitely need EQ, but with 18mm Xmax, I'm not too worried about bottoming them out (and haven't yet, though I haven't really cranked it recently).

My write-up and simple measurements are described here:

http://www.aespeakers.com/phpbb2/vie...hp?f=14&t=1697

Build quality and sound are both excellent IMO. I'm using these up to 500Hz, if you can work with that or a little lower, this might be an option.

Note that the OB12/15 is based off the IB12/15, and is a completely different line of drivers than the Lambda series (which are more expensive).

[Moondog55]

Thanx Saurav, I read your post; Nice woodwork BTW, As I said I omly need 105 dB and crossing to full range as low as possible around 200/250Hz.
I need to have the cash in hand before I'd ask for a build perhaps to be picked up in 7 weeks i'm waiting on a reply to my first E-mail.
Hi Gainphile, any new projects at your end?? I checked your blog a while ago and only saw the OB's with the Jaycar woofers.
I just bought about 12 of those BTW and 8 of the 12's.
YES!! OB is addictive, is it because it is simple and results show almost immediately, cheap to experiment too.