Open Baffle Project
- Dr Bunsen Honeydew
- Old Hand
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- Location: Muppet Labs
#16 Re: Open Baffle Project
Go ahead if you want to fry any wide band amplifiers. That is not cable that is a capacitor.
#17 Re: Open Baffle Project
That's very kind of you Simon, I'll take up your offer if I may.SimonC wrote: ↑Fri Apr 14, 2017 11:06 amHi Ray,Ray P wrote: ↑Fri Apr 14, 2017 7:30 am To get things rolling I've agreed a deal to purchase Phil's pair of Fostex FE167E drive units, which I plan to pick up at Owston in a couple of months. That means the project will take a little time to get rolling but in the meantime I can scout for a pair of the Eminence units and start working on the baffles and bounce a few ideas around.
Ray
I have a pair of 15" Eminence Beta's you can have on extended loan to get you going if you don't manage to find any before Owston. My circumstances (both location and time to build anything with them) have changed since I acquired them and it would be good to hear someone making use of them. Eventually I'll beg them back, but it won't be for a few months/years. I need to put in a couple of RSJ's, remove a wall and build an extension first
Let me know and I can drop them in the car for Owston.
Simon C
Ray
Sorry, I couldn't resist!
#19 Re: Open Baffle Project
Yes, I am. I've tried several alternatives including some expensive stuff. Nothing so far has bettered it.Cressy Snr wrote: ↑Fri Apr 14, 2017 12:25 pm Twisted twin CAT5 speaker cable....anybody still using that?
- pre65
- Amstrad Tower of Power
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#20 Re: Open Baffle Project
There was a pair of Beta 15" on E-bay.
I told Ray about them this morning, but it seems they are gone now.
Was it you Ray ?
I told Ray about them this morning, but it seems they are gone now.
Was it you Ray ?
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
#21 Re: Open Baffle Project
I want to bring something to the party rather than just reproducing what has gone before so...
For a long time I have pondered the idea of building a speaker cabinet using plaster but have never found the time to put it into practice. An open baffle is much simpler than a box when trying to think through the practicalities of working with plaster; being open backed means I can work much more freely and so, hopefully, be able to get a good layup of plaster without lots of voids. So my plan is to construct the baffles, essentially as U channels, using this stuff;
http://www.craftmill.co.uk/casting-moul ... 12sqm-slab
It's the stuff hospitals use for making casts for limb fractures and they seem pretty strong; you can toughen the plaster more by adding a little PVA to the water and a good tough finish should inhibit the plaster crumbling at the edges.
I'll make a mould from sealed MDF and lay up the plaster inside so the outside has a good finish. Should me a messy but satisfying experience!
Cost wise, I don't think there will be much in it compared with birch ply, not pennies but still cheap enough to treat as a learning opportunity.
For a long time I have pondered the idea of building a speaker cabinet using plaster but have never found the time to put it into practice. An open baffle is much simpler than a box when trying to think through the practicalities of working with plaster; being open backed means I can work much more freely and so, hopefully, be able to get a good layup of plaster without lots of voids. So my plan is to construct the baffles, essentially as U channels, using this stuff;
http://www.craftmill.co.uk/casting-moul ... 12sqm-slab
It's the stuff hospitals use for making casts for limb fractures and they seem pretty strong; you can toughen the plaster more by adding a little PVA to the water and a good tough finish should inhibit the plaster crumbling at the edges.
I'll make a mould from sealed MDF and lay up the plaster inside so the outside has a good finish. Should me a messy but satisfying experience!
Cost wise, I don't think there will be much in it compared with birch ply, not pennies but still cheap enough to treat as a learning opportunity.
Sorry, I couldn't resist!
#22 Re: Open Baffle Project
I saw them Phil but didn't bid because of Simon's offer. The listing just ended with no bids so perhaps they'll be relisted.
Ray
Sorry, I couldn't resist!
#23 Re: Open Baffle Project
Blimey, Ray. Won't they weigh a ton?
On that eBay listing that's just finished, if you're interested, try and contact the seller and make him an offer. You never know, you might get lucky.
On that eBay listing that's just finished, if you're interested, try and contact the seller and make him an offer. You never know, you might get lucky.
- pre65
- Amstrad Tower of Power
- Posts: 21400
- Joined: Wed Aug 22, 2007 11:13 pm
- Location: North Essex/Suffolk border.
#24 Re: Open Baffle Project
I reckon that's what someone else has done Greg.
I remember once trying to make a turntable plinth using a bag of "post mix" I had left over.
Disaster.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
#25 Re: Open Baffle Project
I imagine they'll be a 'substantial' lift Greg, but that's OK.
I think Phil was considering a bid, I'll wait and see how the project works out with the loan Beta 15 units.
Ray
Sorry, I couldn't resist!
#26 Re: Open Baffle Project
With the plaster bandage I linked to you can build in a more controlled way, a layer at a time rather than just pouring.
Ray
Sorry, I couldn't resist!
#27 Re: Open Baffle Project
Now, thinking further on the possibilities of plaster, it would be relatively simple, and no more expensive, to replicate the shape of the Quasar baffles. Hmmm...
I have some drawings of the Quasar baffles somewhere.
Ray
I have some drawings of the Quasar baffles somewhere.
Ray
Sorry, I couldn't resist!
- IslandPink
- Amstrad Tower of Power
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#28 Re: Open Baffle Project
Sounds like a nice project - that sort of plaster could be very dense and non-resonant. The Perspex gains by being very dead in the upper mids and treble compared to wood, but this could go one stage further. How thick do you think the material would be ? James's are 15mm Perspex, my wood/Perspex ones use 20mm on the front panels.
"Once you find out ... the Circumstances ; then you can go out"
#29 Re: Open Baffle Project
I would recommend two 15" Eminence drivers per side (Alpha 15A or Beta 15A depending on your bass needs/preferences) to better match the efficient Fostex FE-167E.
I would also recommend simulating your design using the free BASTA program from Tolvan research to get a better idea of the response and potential crossover designs.
http://www.tolvan.com/index.php?page=/basta/basta.php
I would also recommend simulating your design using the free BASTA program from Tolvan research to get a better idea of the response and potential crossover designs.
http://www.tolvan.com/index.php?page=/basta/basta.php
Martin
#30 Re: Open Baffle Project
Martin, I'm currently using one of your OB designs - B200 and twin Alphas per side. I'm looking for a bit more detail in the bass. Would It be a good idea to go for Betas, or would you have another suggestion?