First open baffle project

[Moondog55]

Hi ttan98, I could just put them together but I'm trying hard to improve my woodworking skills, as noted earlier i am thinking of using my Vifa P-13's in a clone of the "Eathers" and just seeing how an OB sounds I do like the mid-range, I'm going to make another pair soon using some surplus drivers that are much better than these, perhaps same configuration perhaps just a combination of only three drivers, the more drivers the easier it is to make mistakes I guess.
Don't worry about your woodworking skills; post your photos's; we just like to see what everyone else is building.
People are free to come round and comment and critique; just email me to arrange a time, we really do need to have a Melbourne get - to - gether like the crew is Brisbane
regards Ted

[PeteMcK]

Hi Moondog, you could try a series xover;
In my OB WWMTM, I used 150uF in parallel with the two woofers;
these connected in series to the two Ms and 3mH in parallel and the T in series with 3.3uF. (LF Xover @ ~150Hz)

You could try various combinations of your 3 & 5.6mH coils to get the sound you want.

Judicious use of the bass tone control is a more efficient way of controlling lows, rather than huge inductors across your woofers.

Cheers,
Pete McK

[Moondog55]

I am thinking that if I just rewire the bass section as a nominal 8R load it will be close enough, experimented late last nite and the 5.6 coil in combination with a parallel cap of 10uF and that seemed to work.
The bottom woofer did not predominate as I thought it might, must be that change from 2Pi to 4Pi that gives the 10inch a presence without overpowering.
The bass these cheap drivers give in a small room is surprising, if I was allowed to buy more woofers ( WAF ) I'd consider another unit using Jaycars really cheap 12inch paper cone with a Qts of 1.46 they sound even more suitable for OB use.

[PeteMcK]

That Jaycar driver is what I used; however, they're getting rid of them, they're on special at the moment for $25, but may not be in all stores...

[Moondog55]

Peter how many of the 12inch did you use? and how did you wire them, where did you cross them and to what?
My local Jaycar owner has a few of the paper 12inch left (6 or 8 of them) I was thinking I'd need at least 4 a side for the power handling, but at $20 each thats only $160-

[PeteMcK]

I used a 12" jaycar and a 10" 'no-name' driver per side for woofers, 2x ancient 8" Magnavox for mids, and a EV 35T horn tweeter, wired as in post 15 above.
Baffle design is similar to the Visaton 'No-Box'.
2 are OK for bass (enough to get comments from the neighbours ), but go for 4 if you can afford it, nothing like surface area to make up for the OB's lack of efficiency...

[PeteMcK]

Original thread here, with pic:
I couldn't bear to throw them away...

(I've changed the tweeter since then)

[Moondog55]

Resurrecting this to comment about the driver selection I made.
I used some very cheap woofers and mid ranges, after finishing the crossover and tweking for a few hours listening I cranked the volume for a short while, "BBLAAATTT" a surround tore off one of the woofers and the paper was flopping around like a fish out of water. Thats what I get for using only 2 $20 woofers in an open baffle and a 200 watt amp.
The woodwork has a few resonce issues but too good to scap, I have some slightly better drivers here ( Jaycar 8inch poly cones) that seem to model OK if given a bigg enough box; try 10,000 litres, thought I'd try them but while they fit the cutout they do not fit the rebate.
I,m thinking I can fit them from the back of the panel; please comment on what happens if I round out the front of the hole with a router, does the air coupling become any more efficient?? or is a half inch round-over too small to have any effect??
One thing I keep learning is that is it is relatively easier to work with good drivers.
Peter I bought a quad of those Jaycar 12inch paper drivers and working on a cheap baffle as a gift for friends of ours, do you know anything about the Magnavox 8WR?/ I'm bidding on a pair in ebay at the moment thinking they may work well as the mid-top

[Moondog55]

I won the auction, I got the drivers for $AUD1.00, it's going to cost $12 in petrol to pick them up though!!