Pi Fours- Low Frequencies [message #47218] |
Wed, 29 June 2005 11:08 ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
Matts
Messages: 359 Registered: May 2009
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Grand Master |
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I was looking at the Eminence data sheets for the 15" speakers, and noticed that they give a lower fs for the Omega series than the Delta Pro(39hz vs. 42hz), and they post a "usable frequency range" that goes down to 35hz for the Omega, and 40hz for the Delta Pro. With that in mind, is it possible to slightly modify a Pi 4 Stage model to ge a little lower frequency response, as I notice the Theatre 4 has that. Is there a tradeoff in the Stage series to get better quality upper bass and/or midrange?
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Re: Pi Fours- Low Frequencies [message #47220 is a reply to message #47218] |
Wed, 29 June 2005 12:24 ![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: 18752 Registered: January 2001
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Illuminati (33rd Degree) |
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The Omega 15 is like so many other high-output 15" speakers, in that it has been designed with electro-mechanical specs that make it work very well in cabinets from 2.0ft3 to 6.0ft3, tuned to 40Hz. The Omega 15 will actually work well in cabinets up to 8.0ft3. Larger than that and the cabinet is best tuned to an EBS alignment. It makes a good subwoofer in a 10.0ft3 cabinet tuned to 30Hz, a la JBL 2235 or 2245. So this speaker is very versatile.This is what you can expect from various alignments of the Omega 15:
Cabinet size Box tuning -3dB -10dB ========================================================= 2.0ft3 40Hz 65Hz 43Hz 3.0ft3 40Hz 50Hz 37Hz 4.0ft3 40Hz 45Hz 35Hz 5.0ft3 40Hz 43Hz 33Hz 6.0ft3 40Hz 40Hz 31Hz 7.0ft3 38Hz 38Hz 30Hz 8.0ft3 38Hz 38Hz 30Hz 9.0ft3 35Hz 35Hz 28Hz 10.0ft3 32Hz 32Hz 25Hz ========================================================= As bandwidth goes up, intermodulation does too, so the lower you push the midwoofer in a two-way speaker, the more midrange will suffer. The Stage four π loudspeaker gives nice flat response and is a good compromise between bass extension and midrange clarity. It is a good all-around speaker that sounds good in large areas with limited boundary reinforcement. It sounds balanced in half-space and quarter-space is good but eighth-space is usually a bit too much. The Stage four π sounds natural and full without a sub, but can certainly be augmented with one. The Theater four π has a little bit different characteristics. It has rising response, and really benefits from boundary reinforcement. It is also good for use in situations where extra midrange presence is required. Having a larger box provides deeper useable response, but at a reduced level. So the Stage four actually sounds like it has more bass, if both are compared in a large room. If placed in corners or floorstanding against the wall in a small or medium sized room, the Stage four may even sound bass-heavy where the Theater four sounds just right.
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Wayne... the kid in the candy store. [message #47223 is a reply to message #47220] |
Wed, 29 June 2005 15:10 ![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) |
GrantMarshall
Messages: 77 Registered: May 2009
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Viscount |
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Hi Wayne.It's been a while. I've seen people on various forums wondering why the moderator "does it". Buy what you want, write it off.... Not a bad deal. Known as "supporting the habit". I hope the summer's going well, the families good, the wheels are fun, and the beer is cold. Take it easy.
Grant.
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Re: Wayne... the kid in the candy store. [message #47225 is a reply to message #47224] |
Wed, 29 June 2005 16:49 ![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) |
GrantMarshall
Messages: 77 Registered: May 2009
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Viscount |
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Hi again Wayne.Weather here is similar to what you have. Humidity is 60-80 % often too and the resulting smog is just nasty. Nice lead in to the cooling system BTW... ![](http://www.audioroundtable.com/emoticons/winkie.gif) It looks engineered to work (I can't think of a nicer thing to say knowing you). No plug of air moving back and forth. That should really make a difference to those that need... Enjoy your summer.
Grant.
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Re: Wayne... the kid in the candy store. [message #47227 is a reply to message #47226] |
Wed, 29 June 2005 18:50 ![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) |
GrantMarshall
Messages: 77 Registered: May 2009
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Viscount |
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You're showing smooth looking prototypes, talking about temperatures, and saying you're very excited. If I had to guess I'd say you KNOW you're on to something good. It will be interesting when you get some numbers together. You didn't mention any downsides yet other than the obvious cost and work involved. Cost should be easily taken care of when compared to cost of thermal failure. Now that you've got the intercooler in there you'll have to work on a turbocharger next. Have fun Wayne. Grant.
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