All Eminence OB

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#464
hakunin said:


Sorry, even i understand few words i'm not able to read it and understand it.
Click to expand...


ashok said:
Is that Serbian?
Any free translation services on the Web ?
Click to expand...

😉
that was meant as answer to Vix's question , regarding Chakija's OB ;

in fact - Chakija - finally tried something else than eeny weeeny T10 , (and maybe some dreky commercial amp ) ...... he tried old , but potent Pioneer amp and was trilled with completely new world of OB bass ;

T10 really can't control 15" that good ........ at least not his T10 .

and - yes - no online Serbian-English translators
 
#465
Hi guys !
I am sorry 4 not answering little earlier 🙂 .

As Zen Mod said ,i finally tried some potent amp...This vintage pioneer A60 has 700w power consumption and therefore lots of power in reserve.This has sooooooooo much effect on the complete sound experience.What was major problem now became main advantage of this loudspeakers.Because of that i had to modify my crossover on Alpha 6 again...Bas was much DEEPER ,still without enough control and mudded ,but with so much presence.It sounded that amp is driving them with ease comparing to little T :dodgy: .Trends is enable to control alphas ,but in very limited boundaries 😉 . Still ,Trends is lot better overall (mid&high ,dynamics ,transparency etc. )
Conclusion : i realized that this set of speakers can sound really great and with proper amp it is just as the other members are describing it -fabulous bang for bucks !
Changes on crossover are regarding alpha 6 and tweeter.
I putted ~1,5db l-pad on 6" and got desired sound lvl ,but i still think that ceramics resistors are degradation to the sound so it is most likely that i will replace them with some metal film resistors.I also putted Mundorf M-cap 0.68uF on highs with earlier mentioned (i hope i did 😀 ) crossover 4 this tweeter.Highs are great...

And Zen ,about that amp... :clown: :clown: :clown:
 
#468
I just finished my crossover for the OB I'm building. 8 inch and tweeter is driven directly by the amp or through a high pass to cut off low frequencies (to limit bass excursion ). The bass unit ( 15 inch Delta-A ) has a shelving filter and a LPF.
The resistors on all filters except the HPF for the 8inch is on small plugable pcb's. The HPF carries the caps and resistors and so can be converted from second order to first order to flat freq resp.

Makes comparisons quite easy. 4x4 inch board carries all including the power supply minus the transformer.

The sound. Can't comment yet but sounds very promising. Been trying, NE5532, TLO72,OPA2134 and others to come.
Bass is really nice. Not 'plenty' like boxes but what's there is VERY good.
Cheers.
 

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#469
Alpha 15" playing as FR

Excuse my ignorance for bringing up this thread because of what may be ,newb question .
Namely ,i wanted to ask if someone has even tried to listen alpha 15" without any crossover ?

Unfortunately i had to sold my alpha 6" and i hooked up 15" as FR and crossed over to st324 which is flat from ~3.5KHZ with 91db which is exactly where alpha is already dropping down with ~20db/oct .

I got better bass ,mid-bass ,i gain some imaging ,and whole presentation sounds kinda balanced than earlier ,but i think i lost dynamic in mid's.

I will definitely try to mount drivers closer to each other and see what will i get+parallel notch filter for alpha 15" to eliminate 10db peak...
What do You think ? Is this worth trying ? Can alpha 15" play nice as a FR to 3.5KHz ?
 
#471
Re: Alpha 15" playing as FR

chakija said:
Excuse my ignorance for bringing up this thread because of what may be ,newb question .
Namely ,i wanted to ask if someone has even tried to listen alpha 15" without any crossover ?
Click to expand...

Yes i did. There is a nasty peak if you look at the specs and its pretty audible. I tried to EQ it but its not listenable.

Unfortunately i had to sold my alpha 6" and i hooked up 15" as FR and crossed over to st324 which is flat from ~3.5KHZ with 91db which is exactly where alpha is already dropping down with ~20db/oct .

I got better bass ,mid-bass ,i gain some imaging ,and whole presentation sounds kinda balanced than earlier ,but i think i lost dynamic in mid's.

I will definitely try to mount drivers closer to each other and see what will i get+parallel notch filter for alpha 15" to eliminate 10db peak...
What do You think ? Is this worth trying ? Can alpha 15" play nice as a FR to 3.5KHz ?
Click to expand...

I agree with choky on this. How about bringing tweeter below kHz with a nice horn? Might be a lot better than using midrange driver. Dr Geddes uses nice tweeter that can go pretty low.
 
#472
Well ,when u think for a sec ,and if u just look at the alpha's magnet ,it is kinda clear that it can't do any good mid with that Mms ...

I don't know...maybe i am starting to tripping :warped: ,but what tha hell ,i will listen this combo until my new 5" FR monacor arrive :smash:

@hakunin
ty for replying ,that's is what i wanted to hear 😉
 
#473
Since I read Geddes papers about wavegides and his Summa speakers, I also started to wonder about a woofer+tweter/waveguide as some combination that can produce good results. With the Alphas (or some better woofer) working up to 800 Hz or 1 khz, and then a tweeter, all of this on OB....(although i despised woofer+tweeter combinations , as seen on many PA speakers)

Btw, I didn't listen to Alpha 15 fullrange, but Beta 15 run fullrange sounds like sh**...
 
#476
Vix said:
Since I read Geddes papers about wavegides and his Summa speakers, I also started to wonder about a woofer+tweter/waveguide as some combination that can produce good results. With the Alphas (or some better woofer) working up to 800 Hz or 1 khz, and then a tweeter, all of this on OB....(although i despised woofer+tweeter combinations , as seen on many PA speakers)

Btw, I didn't listen to Alpha 15 fullrange, but Beta 15 run fullrange sounds like sh**...
Click to expand...


I'm sayin' and sayin' ........ EconoWaveguide , over at Audiokarma forum

😉

but - that's different story , comparing to FR ;

but - what's a man , without two pairs of spks ....... 😉
 
#480
Alpha-15A actually has a fairly light cone for its Sd, especially when you start comparing with other similar drivers from other manufacturers. Of course, it couldn't be too heavy with such a tiny magnet though. Anyway, as far as the Alpha 15 for mids.. it's actually MUCH cleaner than A LOT of MUCH more expensive 15's.. except for that 2 KHz breakup! That huge peak at 2 KHz just kills it all, pretty much rendering it useless for anything other than low frequency duty on an open baffle. On the other hand, wtf is causing that peak? Someone rip off their dustcap, stick something in there, and measure the response at least. I've been dying to figure it out. What if we could turn this cheapo OB woofer into something really nice with greater usability, just by doing a minor tweak or two?

http://www.prodance.cz/protokoly/emin.alpha-15a.pdf
 
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