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Eminence Alpha 15A (Double Fifteen) playing Reggae |
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Elliot Thompson 
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Joined: 02 April 2004 Location: United States Status: Offline Points: 5365 |
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 Topic: Eminence Alpha 15A (Double Fifteen) playing ReggaePosted: 17 March 2014 at 5:22pm |
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Here is a video of a pair of Eminence Alpha 15A speakers I tossed in one of my Double Fifteen Reflex boxes designed for RCF L15 P540. I am definitely planning to build some reflex subs for these drivers by the end of the year.
Best Regards, |
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Elliot Thompson
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lycantheleopard
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Joined: 01 April 2012 Location: san jose ca usa Status: Offline Points: 428 |
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Posted: 17 March 2014 at 6:31pm |
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i would have thought the limited xmax of the alfa series would be a bit of an issue doing sub duty? i know i like them full range but i'm curious as to why you think they would or are doing so well? they would sure make a cheap entry level option for a lot of new builders just looking to try something out
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TMH Music
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Joined: 07 April 2011 Location: London Status: Offline Points: 667 |
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Posted: 17 March 2014 at 7:22pm |
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@Elliot, more details please!!!! What are you driving them with? How big is the cab? What's it tuned to? Just looked at the T/S for Alpha 15a, Qts 1.26?!, BL 7.7???!!!!!!!! VAS 260L!! Is it just me, or does this driver have absolutely no right whatsoever, to sound this good, unless the cab is tuned to a sub-sonic frequency and is 1000 litres+ internal volume? And there was me thinking I knew a bit about speaker design, I'm obviously Manuel (I know nothing!!)
 .Going to throw my rule book away now! Edit for incorrect VAS. Also just crunched the numbers, 12300 litre cabinet, tuned to 12.4Hz!!! Edited by TMH Music - 17 March 2014 at 7:41pm |
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Nothing is foolproof because fools are so ingenious
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Elliot Thompson
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Posted: 17 March 2014 at 7:43pm |
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They are performing well because the measured frequency
response is relatively flat from 200 Hz to 45 Hz in free air (Shown in the
video). So the driver does not need to rely heavily on xmax in order to
propagate bass within the 200 – 45 Hz region.
Compare the free air response of the Alpha 15A to any of the
popular (The drivers you hear many going on about), 18-inch drivers and the
free air response is –3 dB, -6 dB, and/or –10 dB from 100 Hz to 50 Hz. Under
the given conditions the driver relies heavily on xmax to make up the gain due
to the reduction of the frequency response in free air.
There is a reason Eminence calls the Alpha Series “American
Standard.” It follows the same principals found in American Drivers, which were
common with the majority of home audio systems stemming from 1980’s downwards.
In the current box (not designed for the Alpha 15A) you can
see, the frequency response is registering to 25 Hz in the Spectrum Analyser.
Building a proper box based on the TS Parameters you can achieve a response
below 20 Hz. There are lots of parameters to focus on other than xmax. However,
when the majority only focus on xmax, they overlook all the other parameters
and wonder why they are constantly destroying speakers.
Edited by Elliot Thompson - 17 March 2014 at 7:47pm |
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Elliot Thompson
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Elliot Thompson
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Posted: 17 March 2014 at 8:15pm |
Bear in mind, those speakers are in the wrong box (Designed
for the RCF L15 P540 not the Eminence Alpha 15A). I believe the amplifier used
was the 1986, 4 ru Peavey CS 800 playing the bass or the 1976 version on the
left channel. I already took the drivers out of the cabinet and tossed them in
back their cardboard boxes. As I mentioned, in another thread, I don’t use high pass filtering,
which plays a factor on the sound.
Best Regards,
Edited by Elliot Thompson - 17 March 2014 at 8:37pm |
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Elliot Thompson
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Elliot Thompson
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Posted: 17 March 2014 at 8:40pm |
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Here is the ALPHA 15A playing Jazz.
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Elliot Thompson
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Dub Specialist Sound
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Posted: 17 March 2014 at 11:36pm |
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I like the way you think my man and your reasoning/knowledge behind it, not just the same ol' them drivers are crap/inferior like you get a lot of time on here! and without any real evidence/experiance to back it up...just an opinion there crap...
as you have shown you can get an acceptable/decent sound out of them... nice!
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Musical Roots Reggae Vibration is Life! for music is sound...sound is vibration...vibration is energy... and energy begets life. Therein lies my passion!...MUSIC IS LIFE...
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_djk_
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Posted: 18 March 2014 at 12:53am |
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http://www.eminence.com/pdf/Legend_CA154.pdf
This works well in a big box, dirt cheap (about $60 in the USA).
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djk
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Elliot Thompson
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Posted: 18 March 2014 at 12:19pm |
Thanks. Sometimes you need to ask yourself if you are achieving the sound you desire or, are you just getting what others feel is the right sound for you based on their concepts. You really need to know what you want, and having a good understanding of all the TS Parameters will help tremendously. It allows you to pinpoint on areas others overlook or just don’t care about. If the loudspeaker does not offer TS Parameters, you need to measure the loudspeaker. With the amount of software available on the market today, there is no need to speculate which loudspeaker parameter is correct when you are subjected to get the parameters from others. You also need to build your own design. Too many people think they are designers and cannot even figure out WinISD, which is the most simplistic loudspeaker simulator on the market The keyword here is “You.” If you are not willing to make the effort (get your hands dirty) don’t expect anyone else to do it for you. And of course, the naysayers that get argumentative when you don’t agree with their opinions, which are not based on real world experience, bid them good day and move on. Best Regards, |
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Elliot Thompson
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rish
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Posted: 18 March 2014 at 2:24pm |
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You really need to know what you want, and having a good understanding of all the TS Parameters will help tremendously. It allows you to pinpoint on areas others overlook or just don’t care about. If the loudspeaker does not offer TS Parameters, you need to measure the loudspeaker. With the amount of software available on the market today, there is no need to speculate which loudspeaker parameter is correct when you are subjected to get the parameters from others. You also need to build your own design. Too many people think they are designers and cannot even figure out WinISD, which is the most simplistic loudspeaker simulator on the market The keyword here is “You.” If you are not willing to make the effort (get your hands dirty) don’t expect anyone else to do it for you. And of course, the naysayers that get argumentative when you don’t agree with their opinions, which are not based on real world experience, bid them good day and move on." Best Regards, [/QUOTE] Probably one of the best responses i've read in a long time. agree 100%. well said Elliot. more people should adopt this attitude, then maby they will learn a thing or two. Rish
Edited by rish - 18 March 2014 at 2:27pm |
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matt mcginn hi fi
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Posted: 18 March 2014 at 9:53pm |
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nice one Elliot
 I'm going to dig a little deeper and not discount things too quick with my project |
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Elliot Thompson
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Posted: 20 March 2014 at 1:31pm |
Experimenting is the best means of learning. Best Regards, |
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Elliot Thompson
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lycantheleopard wrote:
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