punisher - measuring
Printed From: Speakerplans.com
Category: Plans
Forum Name: Punisher and X-tro
Forum Description: Discussion / Questions about the Punisher and X-tro
URL: https://forum.speakerplans.com/forum_posts.asp?TID=1060
Printed Date: 27 March 2026 at 10:58am
Software Version: Web Wiz Forums 12.08 - https://www.webwizforums.com
Topic: punisher - measuring
Posted By: Jez_Ultra
Subject: punisher - measuring
Date Posted: 07 December 2004 at 11:43pm
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I'll hopefully be building a punisher horn nxt week, with a second hopefully following over the christmas period (if i don't get too wasted). I'll post photos of the build once their complete. The first thing I want to do though is to make some decent measurments of the cab. what should i be measuring, how should i be meausing it and what should i be measuring it with. A computer is no problem and I have a pretty good sound card, i've heard mention of special microphones and pre-amps. I'm expecting to run four of these horns off a Inifinite8 (2 x 2400Watts), any thoughts on this anyone?
Jez |
Replies:
Posted By: Tony Wilkes
Date Posted: 08 December 2004 at 8:34am
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Get True RTA for the comp, a small mixer with phantom power i.e.
Behringer MX802a and a Berry ECM8000 Mic. This will do the response for
you but to do SPL you will need an SPL meter to calibrate your system. Tony |
Posted By: Timber_MG
Date Posted: 08 December 2004 at 3:34pm
| Try and get a mixer that will give you an output pre-chanel fader & eq. I have a little Yamaha 4-chanel mono mixer that works a dream in conjunction with the Behringer ECM8000 running pre-aux. I have had great results with Speaker Workshop. |
Posted By: tb_mike
Date Posted: 09 December 2004 at 6:57am
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Make sure that your levels are both adaquate but not clipping Make sure that you measure your frequency response at a SANE spl where the mic will be linear eg at 1watt input. Use a couple of programs for variety and repeatability,and interest. Learn how to use/practise Speakerworkshop BEFORE the day - some hate it! The ECM8000 will be nonlinear above 110db probably-it Definately is at 120db according to linkwitz. so SPL measurements wont be happening unless you can find the local car audio SPL meter...(usually linear to 130db but give too high readings above that unless the latest models) Goodluck! Cheers! |
Posted By: tb_mike
Date Posted: 09 December 2004 at 6:58am
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and http://homepages.paradise.net.nz/sbk1/ssi.htm  |
Posted By: freddyi
Date Posted: 09 December 2004 at 4:24pm
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I like to look at ground plane and above - put mic on floor or ground for GP - outdoors will reveak ripple mic IMO could go back further than 1M - EV used ~3M indoors - take 1M then further back and if wideband horn/direct raditoar, plot in an arc at center height of horn going in 15 degree increments at distance where it wil typcially be heard. take a note pad to keep track of plots, conditions, obervations if outdoors, mark your mic and speaker spots for future reference as nearby objects such as house will have effect so at least these effects will be constant in future testing. look for noise floor and mains frequency leakage - I'm sloppy and sometimes get 60Hz US plus ~15K monitor watch all levels to avoid clipping - with something like TureRTA , sine overtones can be checked vs indicated level. U can make attempt at two tone sine modulation test - -(google John Allen + modulation distorion) but first - do some harmonic distortion testing with various sine frequencies and low wattage. don't fry anything with sine!!! climbing distortion rate on my PV FH1 will set in by 10 watts re:Mike E. & ECM8000 will have to look at mic overload - am probably OK outdoors on sine seeps and pink noise will be cool to see hi-res on Punisher & Tuba |
Posted By: Jez_Ultra
Date Posted: 09 December 2004 at 8:44pm
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the ECM8000 is seriously cheap at £39, doesn't really shout precision equipment at me. neither does it's datasheet make reference to any specifictions/standards i'd expect to be linked to a measuement device. spl meters obviously use a microphone so is it just a case of the ECM8000 not being up to the task, or something else. I'd never use a car audio SPL meter, its bound to give a reading of 400dB
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. Posted By: freddyi
Date Posted: 09 December 2004 at 8:58pm
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imo cheap ECM8000 aint' gonna miss much - should be good nuff
from 20-15K - John Murphy (TrueRTA) recommends them (and they're OK for
recording) - one could have 8000 calibrated agasinst a known
standard - but not sure if worth cost - goes way lower flat
than my EV dynamic omnis. dunno ECM8000 overload point w. 48vdc phantom provided by MX602, etc mixers here's hear-port of my little BP6B box : http://home.earthlink.net/~buddhaboy2/BP6B.jpg - http://home.earthlink.net/~buddhaboy2/BP6B.jpg |
Posted By: Jez_Ultra
Date Posted: 09 December 2004 at 10:40pm
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i guess it'll do for the job in hand, i#ll be able to buy another driver instead of spending more money on a mic.
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Posted By: Timber_MG
Date Posted: 10 December 2004 at 7:51am
| An electret capsule will be very, very accurate at LF, so I wouldn't worry too much about that. One can get the mic calibrated and determine its sensitivity for true SPL measurements if you want to, but it's still an invaluable tool in setting up one's loudspeakers (esp. with LMSs). |
Posted By: Dave Slater
Date Posted: 10 December 2004 at 10:46pm
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can't remember who but someone got their ECM8000 calibrated (thank you if you're reading!) anyways whilst it's exactly right for theirs it can act as a generic guide for us it's an FRD file so you'll have to use SPL Viewer to actually look at it but a fair number of programs will let you import it (speaker workshop does i believe) anyways here you go - http://homepage.ntlworld.com/dave.slater23/ecm8000cal.zip - ECM8000cal.zip
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Posted By: tb_mike
Date Posted: 11 December 2004 at 1:44am
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Interesting.I wonder how much difference there is between various
products of that model,considering its electromechanical its probably a
decent variation. Cheers! |
Posted By: freddyi
Date Posted: 11 December 2004 at 2:03am
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WAY KOOL ! opens up immediately in Praxis demo nice LF response , and that example only ~1.5dB down or so at 20Hz - doubt if SM80 any better (didn't love SM81) many speakers aren't going to be doing much (good) at 20hz |
Posted By: Jez_Ultra
Date Posted: 12 December 2004 at 4:08pm
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punishers or HD15's la di da di da da. amn i'm having second thoughts about the punishers. Thinking i'd be better off building some HD15's and some X1's to go under them at a later date. On the other hand i could put some X1's under the punishers as well. Or just build X1's and put some X12's up top. god damn this indescisivness. Thinking that I might build some MT12's (split MT122's like doms) instead over christmas. And what about that 12" x 2" Coaxial on Speakerstore - not being able to read dutch (babelfish translation says and horn combination becomes using special RVS affirmative profile in 12" waveguide assembled. For ordering this profile contact can take) does this mean there is a special assembly needed as a wave guide. The staples of this new rig are going to be funk, hip-hop and reggae - perhaps i'd best go with direct radiating. hellllpppppppp. at this rate i'm never going to be finished before the begining of next summer. p.s. saw some peeps running around with a geodestic shaped marque in the depths of norfolk last year(2003) - anyone know who/what system this was? I'd quite like to make one. Thinking about it they may have been called 23hr Techical Support. |