[Derockster]

Hi guys, I am in the process of building MJK's OB design using the Eminence Alpha15 with the Fostex 103. Attached are some photos of the actual baffle with an edge around the sides against my better judgement. Question is will this add or subtract from the sound of the baffle.

Regards


Cleaton Parris

[DanH]

You in effect just made the baffle a little wider. I doubt it would affect the sound very much. I had deeper wings on mine and they sounded fine. How did you get that nice smooth finish?

[Guy 13]

Hi Derockster and all Audio Circle members.

Look to me that the base is not wide enough,
the baffle might tip over it a child bang in it with his tricycle.

Just my humble opinion for what it's worth.

Guy 13

[JCS]

By adding the 'sides' you make the baffle stiffer--which should improve the sound. 

I built a variation on that design using FF85K and Alpha 15.  I added 2x4s to brace the baffle, along with sloping sides making it even stiffer (and extend the low end a few Hz).  I am extremely pleased with the result.

Cheers,  Jim

[planet10]

We built an FF85k A15 variation based on Jim's work and a surplus tabletop, they worked well, but eventually drivers surplused and the baffles (with some vintage 15s) passed on as they were not friendly enuff for my room. They had a single vertical stiffener of simialr size to your wings, they are small enuff as to be unlikely to do anything acoustically.

Love the red

Do note that in practise the FE103 has been found to need some padding to bring its level down.

dave

[Derockster]

Hi everyone thank you for all the positive comments shared.

Dave I too love the red thanks

Guy13 will look into better stabalization thanks

DanH they are painted with truck paint plus loads of clear.


Regards

Cleaton

[JeffB]

How do you cut the circles?
I don't have any tools to cut perfect circles.

[Derockster]

Get a friend with a wood work shop to cut them for you, that's what I did!

[Squidspeak]

How do you cut the circles?
I don't have any tools to cut perfect circles.

On the P/E tech talk forum, there is a member that will CNC baffles. Prices
seem reasonable and shipping a pair of flat baffles should not be too bad.

[Derockster]

Hi guys, would the fostex 108sigma work in this project and would I have to make any changes to the capacitor and inductor?

Regards

Cleaton

[MJK]

Hi Cleaton,

The Fostex FE108E Sigma will work, I have used it opn my experimental baffle and it sounds very good. However the passive crossover would probably need to be adjusted to get the most out of the design. You could try it with the original crossover but it would not be optimal.

Martin

[DanH]

I tried the 108 in my MJK ob. While it had better top end it did not blend with the alpha 15 as well as the 103 does. There seemed to be a whole in the lower midrange. Maybe the crossover needs to be higher for the 108.

[Derockster]

hey Martin could you give any suggested adjustments to the passive crossover?

Regards

Cleaton Parris

[MJK]

Cleaton,

I was using an active crossover when I had the FE-108E Sigma drivers in the OB so I do not have a passive crossover worked out. I listened to them for about six months, liked what I heard, and then changed over to the FF85WK drivers again using the active crossover. I am constantly swapping drivers to try different combinations.

Sorry not much help,

Martin

[Derockster]

Hi Martin, back on the topic of the 108's can you tell me what active crossover you were using.

Regards

Cleaton Parris

[MJK]

Hi Cleaton,

I am using a dBx Driverack PA active crossover. I have had it for over 5 years and it has worked flawlessly for several different dipole speaker designs. Easy to adjust on the fly and saves lots of configurations that can be recalled later.

Martin

[Derockster]

Hi Martin, I placed the fe108's in the baffles yesterday and listening to them on their own i am really pleased with the sound. I will be purchasing the dBx Driverack active crossover to use in this system. Thanks for your input,take care

cleaton