Omega 15 alternatives? [message #52945] |
Thu, 11 December 2008 10:52 ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
reguax
Messages: 21 Registered: May 2009
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Hi everyone Omega 15 is out of stock at my local dealer (I'm not in USA) KAPPA PRO 15 ALF2 seems to be a good replacement Has anyone tried it? Will it work in a 4Pi cabinet? I've seen posts about it, but they are very old, so I'm asking again in case someone has any news ![](http://www.audioroundtable.com/emoticons/smiley.gif) Thanks in advance!
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JBL 2226 [message #52946 is a reply to message #52945] |
Thu, 11 December 2008 11:41 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18749 Registered: January 2001
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Illuminati (33rd Degree) |
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The four π loudspeaker asks a lot of its midwoofer, as does any two-way loudspeaker designed to provide uniform directivity. The crossover point has to be fairly high in order to match directivity of the midwoofer with the tweeter, because it requires the midwoofer's collapsing directivity to match the radiating angle of the tweeter. That doesn't happen until around 1kHz.As a result, midwoofer selection is critical. The quality of the midwoofer is extremely important, because it is what voices the speaker through the critical midrange. Try to find a JBL 2226 if you can.
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Re: JBL 2226 [message #52947 is a reply to message #52946] |
Thu, 11 December 2008 11:53 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
reguax
Messages: 21 Registered: May 2009
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Chancellor |
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Ok, the warning is clear ![](http://www.audioroundtable.com/emoticons/smiley.gif) I'm considering JBL like an upgrade, I can't afford it at this time. I will manage to get the Omega Thanks Wayne!
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Re: Omega 15 alternatives? [message #52950 is a reply to message #52945] |
Fri, 12 December 2008 15:03 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
reguax
Messages: 21 Registered: May 2009
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Chancellor |
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I have a 'little' problem. I didn't notice that the required drivers for 4Pi are "Omega Pro 15" while the current eminence model is "Omega Pro 15A". Now, I'm the owner of a useless(???) pair of Omega Pro 15 A. Will the 4Pi work with Omega Pro 15 'A'? Should I throw them to the trash can? Thanks!
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Re: Omega 15 alternatives? [message #52952 is a reply to message #52951] |
Sat, 13 December 2008 09:30 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
reguax
Messages: 21 Registered: May 2009
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Chancellor |
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Good news Wayne ![](http://www.audioroundtable.com/emoticons/smiley.gif) I thought I had purchased the wrong drivers However, I'm still a bit confused. The specs for 15A at eminence web site and the specs from the link at Pi site are different. Parhaps the values describe similar drivers and I can't see it? Could be the case, I just see numbers, I don't understand them. But these numbers look very different. For example, from eminence website: Resonance 33Hz Usable Frequency Range 51Hz-1.7kHz Sensitivity*** 97.3 DC Resistance (Re) 5.28 Coil Inductance (Le) 1.04mH Electromagnetic Q (Qes) 0.33 Mechanical Q (Qms) 5.69 Total Q (Qts) 0.32 Compliance Equivalent Volume (Vas) 9.1 cu.ft. From the PDF document at Pi web site: Resonance 39hz Usable Frequency Range 35Hz-2Khz Impedance (Re) 4.98ohms Coil Inductance (Le) 1.48mH Electomagnetic Q (Qes) 0.37 Mechanical Q (Qms) 8.57 Total Q (Qts) 0.35 Compliance Equivalent Volume (Vas) 6.92 cu. ft. Thanks!
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Re: Omega 15 alternatives? [message #52953 is a reply to message #52952] |
Sat, 13 December 2008 12:01 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18749 Registered: January 2001
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Illuminati (33rd Degree) |
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Those specs describe a compatible alignment. You could almost say equivalent but since the numbers are different, I like to say they're compatible instead.Eminence has done this a lot over the years. They're fast and loose with their spec sheets. But don't take this as a slight on Eminence, in fact, maybe it's more honest to republish specs every year or two. After all, materials change slightly over the years, suppliers change, different vendors are subcontracted, etc. In fact, you can even take the same driver, test with a 0.1v signal and get one set of numbers, retest immediately with 1.0v and get a different set of numbers. Run the speaker at high power for a few minutes and retest and it wil be entirely different. The important thing is that the electro-mechanical specs, when used in a system, provide the desired response curve. They do in every case I've found of Eminence drivers that have shifted from one season to the next. They're different but not in a meaningful way. That's why I don't get too excited about changing spec sheets posted, if you sample a few yourself, you'll likely find matching numbers, or very nearly. They're compatible parts.
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Interesting Delta 15A pro specs are similiar... [message #52954 is a reply to message #52953] |
Sat, 13 December 2008 12:33 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
spkrman57
Messages: 522 Registered: May 2009
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Illuminati (1st Degree) |
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Wayne, I measured a pair of Delta 15A pro drivers I have and this is the result using WT2: Revc 5.7 ohm fs 40 hz Qes .38 Qms 3.99 Qts .35 Zmax 53 ohm Le 1 mH eff 97.8 db/watt (3.874 %) Vas 8.3 cu ft The other driver measured really close to these specs also! I'm looking at using a 7.75 cu ft cab. What would you recommend for tuning the port frequency??? Regards, Ron
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Vas=8.3, Fts=40, Qts=0.35 [message #52956 is a reply to message #52954] |
Sat, 13 December 2008 13:00 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to previous message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18749 Registered: January 2001
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Illuminati (33rd Degree) |
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I'd probably put a woofer with specs like that in a cabinet from 2.5ft3 to 5.03 tuned to 40Hz, just like the JBL 2226 or Omega 15. That is slightly overdamped, so it's good inside a room and also thermal shifts won't make it peaky down low.If using it in a larger box like you're talking about, I'd probably shift the Helmholtz frequency down a smidge, say 35Hz to 38Hz. All those values form kind of a continuum of alignments. Big box, from 6.0ft3 to 10.03, the port should be somewhere between 35Hz and 38Hz, larger tuned lower. Smaller box, below 5.0ft3, tune to 40Hz.
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