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Need Help Simulating dual reflex for Lowrider 18 |
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DiscernAudio 
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Joined: 08 June 2011 Location: Alabama Status: Offline Points: 327 |
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 Topic: Need Help Simulating dual reflex for Lowrider 18Posted: 08 November 2011 at 6:56pm |
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I am building two dual 18 reflex cabs for Peavey's Lowrider 18.
Each cab will be powered with a QSC PLX3402 (bridged 4 ohm) I am using bass box pro for cab design so far. Music that will be played is primarily Drum and bass, dubstep, roots, and hip hop I am looking for a nice flat response, but cant seem to find it without huge volume. I think I would like to aim for Vb=400 L or below. Could someone maybe shed some light? Speaker specs are... Znom (ohms) 8 Revc (ohms) 6.21 Sd (Square Meters) 0.134 BL (T/M) 22.17 Fo (Hz) 28.9 Vas (liters) 288.0 Cms (uM/N) 113.3 Mms (gm) 198.20 Qms 9.07 Qes 0.451 Qts 0.429 Xmax (mm) 9.6 Le (mH) 0.87 SPL (1 W 1m) 96.0 no (%) 2.65 Vd (cubic inches/milliliters) 145 / 2375 Pmax (Watts pgm.) 1600 Disp (inches/milliliters) 235 / 3852 Also, some of these specs copied from the spec sheet dont add up? Sd, Xmax, Vd? Qes,Qms, Qts, BL? Also, peavey recommends 6 cuft/driver tuned at 34 hz, but if you input their recommened port size and length, it doesnt add up either? |
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aperrado
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Posted: 13 November 2011 at 4:10am |
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Hi , no to much answers, but ifi you decide to make this project keep updateds on
good luck. |
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Im hard to learn but still asking
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MarjanM
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Posted: 13 November 2011 at 11:26am |
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Why dont you just copy Peavey QW218 box?
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Marjan Milosevic
Head of engineering Bold Audio Inc www.boldaudioinc.com http://www.facebook.com/pages/Bold-Audio-Inc/323691856723 |
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RealitySound
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Posted: 21 December 2011 at 12:13am |
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www.peavey.com/media/pdf/manuals/80304779.pdf
there are 3 designs peavey gives you- small, med, & large cabs. Bigger the cab lower the cutoff. |
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We learn something every day, and lots of times it’s that what we learned the day before was wrong.
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rffrecords
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Posted: 08 January 2012 at 10:44pm |
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The only way to keep your boxes under 400Lt is to use the isobaric configuration (driver properties->configuration tab in BassBox). You lose sensitivity (SPL) but required volume drops to one querter of the standard twin or push-pull configurations!
Those peavey 18s didn't impress me at all but since it appears you got 4 of them I think you better put them to some good use. I managed to get an SPL of 124dB with 1100watts (your amps can't deliver more) from 31Hz up (-3dB), flat from 41-220Hz using a vented box of 275Lt and 4 vents 6 inch diameter and 380mm long. That gives an at least 6dB peak caused by the vents at 295hz, but if you cross the subs 180 or 150hz down, it doesn't matter. If you are still following your thread and post a reply, I could find the time to upload photos and some BassBox files. Also do some research on the isobaric configuration (as this if the only way to go if you want a flat response with these drivers for less than maybe 900Lt!) and on how to build an isobaric chamber (it isn't that difficult). |
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Steve_B
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Posted: 08 January 2012 at 11:13pm |
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based on the figure you posted above winisd comes up with the following max spl graphs.
 Form these results there seems little point in using a larger cabinet.
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levyte357
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Posted: 08 January 2012 at 11:27pm |
Have you bought the amps and drivers already ? |
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"Who am I? I'm the guy who does his job.. You must be the other guy".
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rffrecords
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Posted: 08 January 2012 at 11:47pm |
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On my previoys post 275 Lt is a mistake, I meant 330Lt. Also I made use of the high pass feature of the QSC amps modelled as high pass at 30 Hz with a Q of .65 (just my guess it must be somewhere between 0.6-0.67 i guess). High pass is essential for PA. Moreover PA cable runs will add some resistance diving Qts closer to 0.5. All in all the driver is barely good for vented boxes. Bad PA woofer!
Jsadler is asking for "a nice flat response" That's the best that I managed to get with bassbox. I haven't winISD installed on this computer and would like to what winISD gives because as jsadler said the driver's T/S are tricky to say the least. |
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rffrecords
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Posted: 08 January 2012 at 11:54pm |
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Sorry that is the link to my frequency response:
http://www.2shared.com/photo/NmI6PVg6/123.html |
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levyte357
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Posted: 08 January 2012 at 11:57pm |
Exactly why I asked if he had bought them already.  Also, buying an amp specifically for 4 ohm bridging on sub, with sub heavy material, would point me away from PLX3402. Edited by levyte357 - 08 January 2012 at 11:58pm |
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"Who am I? I'm the guy who does his job.. You must be the other guy".
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DiscernAudio
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Posted: 26 March 2012 at 6:39am |
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I am no expert in this field but what's wrong with this?
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Elliot Thompson
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Posted: 26 March 2012 at 6:04pm |
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Nothing. The simulation delivers a good response and, offers no power compression from a frequency versus wattage perspective. I believe those who are complaining about Peavey are refering to the old Black Widow. The Low Rider is a completely different driver. Best Regards, Edited by Elliot Thompson - 26 March 2012 at 6:06pm |
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Elliot Thompson
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jsadler wrote: