All Eminence OB

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Yunick

Member
Joined 2006
Well this will be my first speaker project that I begin without full documentation... I have preavius build the DIY2000 speaker, Cyburgs needle, Mumma Mosen clon... But the more I read about open baffle's the more I feel the urge to try them..

But as a student I'am not loaded with cash so it has to be a somewhat limited budget.. So with som help from Zen Mod the project stood clear..


The plans are to use Eminence spks in a open baffle configuration..

Beta-15 up to 150Hz
Alpha-6 from 250-300Hz
APT-80 from 10000-15000Hz.

XO will be simple serie filter (6db/octav).

The drivers can be had for $350 in Sweden..

Baffle size is 450x1350mm. The sides tapers to the top with a base of 350mm.


There are also plans on giving the Alpha-6 a new phase plug and EnABl treatment.. This is very important to bring out the best from Alpha driver..



A thread i useless without pic's, right ;) Here they are:

http://www.diyaudio.com/forums/showthread.php?postid=1278400#post1278400


These will be driven by my babbelfish-j/Aleph P1.7/dddac.de combo.
 
Zen Mod

Zen Mod

Official Court Jester
Joined 2003
zenmod.in.rs/
Paid Member
ugly!

:devilr:

hehe I bet that sound is dreky .........



worth to mention JamesD (if I rem. correctly ;) ) and his ugly OBs......

also Mr. Lampizator ...... (google for it- man is nutz ! )

Yunick's xovers are simple....

bass choked at 6db/oct - 150Hz

main spk - Alpha 6 just capped at ~300 ,also 6db/oct

Apt80 - just capped via 1,5uF ~13K......what else than 6db/oct ; yes - L-pad is still missing (to bring it down some 8-9 db) also felt on back of Alpha 6 etc , just because Yunick have some obligations to soften WAF slightly :devilr:
 
adason

adason

music soothes the savage beast
Joined 2004
edsaudiopages.blogspot.com
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Yunick,

first of all, they are not as big as you think. Many 3-way monkey coffin floorstanders are the same size. I have seen and even had much bigger open baffle speakers. They might not actualy be low waf, as long as you put some grill over the front (or get rid of wife).
You might experience less deep bass, for bass cancelation and not enought bass surface area, but on the other hand bass should be clean.
If that happens and you run out of cone excursion in deep bass, just close the woofer behing in closed box, keep the midrange open baffle. Thats a best thing which can happen to the midrange. I would even use second tweeter to radiate to the back. That depends on personal taste.
Good luck.

ed
 
Y

Yunick

Member
Joined 2006
hakunin said:
They are wonderful!
Click to expand...

Thank you.. :)

adason said:
Yunick,

first of all, they are not as big as you think. Many 3-way monkey coffin floorstanders are the same size. I have seen and even had much bigger open baffle speakers. They might not actualy be low waf, as long as you put some grill over the front (or get rid of wife).
You might experience less deep bass, for bass cancelation and not enought bass surface area, but on the other hand bass should be clean.
If that happens and you run out of cone excursion in deep bass, just close the woofer behing in closed box, keep the midrange open baffle. Thats a best thing which can happen to the midrange. I would even use second tweeter to radiate to the back. That depends on personal taste.
Good luck.

ed
Click to expand...

Thanks for your reply and suggestions.. I will keep them in mind..



I could not wait for the proper parts to arrive so I hooked up a temporary XO. Elecktolytics bypassed with MKP for Alpha-6, Mcap for tweeter..

XO used is:

8.2mH choke for Beta-15 (150Hz),
58uf for Alpha-6 (340Hz),
1.5uf for APT (13kHz).

L-pad for tweeter is still missing..



Impressions...


The sounds very effortless.. The sound stage is very deep and wide like never before... It's like the spks have disappeared (almost)..

I was worryed about thin bass... I shouldn't have.. The bass is very, very good.. A bit lighter the my box spks,but much cleaner..

They still need alot of work but the initial impression is very, very promising..
 
Pano

Pano

Administrator
Joined 2004
Paid Member
Those are great! Cool idea. And there aren't' THAT big.

The dimensions are almost exactly like crazy Lukasz "Lamipizator" Fikus' baffles.

It's funny to see similar projects form the other end of the earth. :) You are in the far, far north and I'm in the tropics, but I've been out sawing baffles of the exact same size today.

The all Eminence design is really cool. Is that Choky's idea? And it looks like you might have just enough room to squeeze in another Beta 15, if you feel need for more bass.

Nice work. Hope you like them - keep us informed.

If you ever get tired of them, just pull the drivers, hook up some reindeer and off you go across the snow!
 
Y

Yunick

Member
Joined 2006
tinitus said:
I remember some people laughing the many times I have suggested the Alpha-6

Its very nice to hear that it really is good ... nice project !

I wonder why you use a horn tweeter ... I didnt think the 6" would have that high SPL ?
Click to expand...


Thanks for your kind words..

The Alpha supprised me too.. It's a very promising driver indeed..

I used the horn tweeter based on Zen Mod's recomendation. I have also read other people's xperience with that tweeter aswell.. It need to be taken down 8-9db..
 
Inductor

Inductor

Member
Joined 2006
The Eminence beta 15 peaks 10 dBs at 2K. Difficult to get away with that with a 1.order xover.
Also maybe a small amount of impedance in the pair xover/speakers around and after 2K because of tweeter resonance and 1.order xover, this one maybe not so nasty since the 6" alpha is well behaved and you can take it up a little more in frequency (to 3K/4K) if nedded. Not bad... after small ajustments in the xover thought. Since the main idea here is the 1.order xover I think this sub is not really up to the task.
 
Y

Yunick

Member
Joined 2006
panomaniac said:
Those are great! Cool idea. And there aren't' THAT big.

The dimensions are almost exactly like crazy Lukasz "Lamipizator" Fikus' baffles.

It's funny to see similar projects form the other end of the earth. :) You are in the far, far north and I'm in the tropics, but I've been out sawing baffles of the exact same size today.

The all Eminence design is really cool. Is that Choky's idea? And it looks like you might have just enough room to squeeze in another Beta 15, if you feel need for more bass.

Nice work. Hope you like them - keep us informed.

If you ever get tired of them, just pull the drivers, hook up some reindeer and off you go across the snow!
Click to expand...

Thanks for your reply :)

I guess it's a small DIY/hifi world we live in after all :)

Maybe they aren't that big on second thought.. My wife did have a hard time letting them in the house thou..

Lukasz "Lamipizator" and Choky got me interested in OB's, but the idea's are all Choky's..

It would be very interesting to see a pic from your work and maybe a little more info?

I hope the snow stays away for atleast three more month thou ;)
 
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