posted
HI once again, ok, ill start with what i have i have a 92 pontiac sunbird(2door) with 2 12inch jbl gt(dual voic coil) sub woofers in a four foot custom built ported box with the 4inch wide 12inch long ports and subs facing 4inches away from the trunk. I take out my back seat for the competions. I have an Mtx RT 2400x amp about 375 to each sub. I have a 1 farrad lightning cap, and a kenwood kdc8011 radio. well i just recintley got this radio and am hitting high 142's i used to hit 143's easy, and my high is 145...my old radio was the kenwood kdc3001(not 4-volt like the new one). Why have i gone down my last 2 events, i even went out and got a 105 amp alternator. Please, someone help me...i should be hittin 145's instead im doin 142's the past 2 shows. Also, i was told to get a line driver that would help. Please any suggestions on where to set my amp(hi freq or gain, etc..) and postion my subs at. Thanx Iggy
------------------ If you aint down with the iggster and his sounds i got 2 words for ya JBL Bass :o)~
posted
Well the weather can affect the spl. If you played the equipment before the run or if the coils/amp is warm when you do the run. As the coil heats up the resistance goes up and that of course means less power and that will give less spl.
There is more then one possibilty with this. Also the meters could have been "off"....But then again is there a meter that is ever perfect?
------------------ _____________________ Member of "Team Underconstruction" Can you say 172dB outlaw 165+ legal in a yugo? We can:-) 1999 USAC Finals Qualifier Usac Sactioned Judge -----Judged----- 1999 Spring Break Nationals 1999 Midwest Regional 1983 Camaro-152dB old system..new system on the way. -Irc Chat Room- chat.talkcity.com ports 6667,6668,6669,7000 Room Name #auto-audio I am the room coordinator for this room. Stop by sometime and say hi...We are busy after 9:00cdt usually.
Posts: 8035 | From: Huron,Oh | Registered: May 1999
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DragQueen
unregistered
posted
Another thing that might affect it are the meters. If they are different kinds or something they might not read the same numbers. If it was the same meter at each run through that probably isn't why the numbers are different though.
------------------ Maybe my two cents doesn't count, but I am offering it anyway!
posted
Also on that meter note..I have seen the exact same meter read different from one day to the next. Heck the mic could have been dropped or the like I said b4 the weather...there is alot that can affect the spl...
------------------ _____________________ Member of "Team Underconstruction" Can you say 172dB outlaw 165+ legal in a yugo? We can:-) 1999 USAC Finals Qualifier Usac Sactioned Judge -----Judged----- 1999 Spring Break Nationals 1999 Midwest Regional 1983 Camaro-152dB old system..new system on the way. -Irc Chat Room- chat.talkcity.com ports 6667,6668,6669,7000 Room Name #auto-audio I am the room coordinator for this room. Stop by sometime and say hi...We are busy after 9:00cdt usually.
Posts: 8035 | From: Huron,Oh | Registered: May 1999
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posted
Hey, I think you may be lacking some major port area there... I built a box for a single 12 of that for my girlfriend, and if I remember, the specs you gave us are what are recommended for ONE 12... You may want to add another = area port, that should help things out.
------------------ 4 DD 9515s Many Many Class D's Big *** Blazer Team Hertz Member
Posts: 1770 | From: Baton Rouge, LA | Registered: May 1999
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posted
doh!, sorry i have 2 4inch ports, 12inches deep apeace...and about the mics bein off ive hit 142.8's the last 2 shows, it didnt help that the people putting them in were idiots, the last show they didnt even have the jigs...but..all ive done dif from when i hit my 145 to my 142's now is go with a 4 volt radio.....i dont get it, its supposed to help not make me go down?!?!?!?!
------------------ If you aint down with the iggster and his sounds i got 2 words for ya JBL Bass :o)~
posted
You need to remember that with a new radio you have more input voltage now. Your gains will have to be set differently. You need to turn your gains all the way down. Then turn your radio up to the loudest volume you want to use. Not neccassarilly the MAX because it will have more distortion. I usually use around 5 to 10 down from the max. EX: MAX is 35 use 25 or 30. I use incriments of 5 always seemed to work better. Don't ask me why. Then put in the CD which you competed with when you hit 145. Turn up your gains until the bass begins to sound sloppy. At this point you are overdriving the amp, other words clipping the amp. Play with all of you eq's or crossover gains as well before you fiddle with the amp. Turn those gains up minimally or maybe even half way up. They produce alot of didtortion at times as well. Another way is to have about 30 extra dollars available at shows. Since I am guessing you don't have a mic to use for free. Go through a number of times, each time trying something different each time. Adjust your gains as you go. You should be able to figure something out. One more thing is to use an Osciliscope(mispelled in know it). Adjust all of your gains to the max without dissrupting the wave. In other words keep the line a smooth wavey line, not chopped off at the top. This doesn't always create the highest spl, but you can almost guarnatee the best sounding subs, with little chance of blowing them. Maybe use something besides kenwood.
------------------ 1 10 going for 145+ 2 10's going for 150+ Wish me luck F.T.M.
Posts: 169 | From: Duluth, GA | Registered: May 1999
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posted
The best way I have found to max out your amp is as follows: unhook your woofers, set the head unit bass control to flat zero, turn the volume up 3/4 on the head unit, turn all bass gains off and play a solid bass tone as you find on dB jams cd. Then using an A/C voltage meter read the outputs from the amp. Use a screwdriver to adjust the gain and turn it up slowly until it peaks. (note-your peak output is usually not full crank) Next hook the subs back up and you are finished. Take note of what the volume was on the radio and the next show that you go to, use that same volume level and use test tones (not sweeps or bass songs) for max spl. oh and if your radio has a loud button, use it. This is by no means perfect, but it can help. Just a tip from shock!!!
------------------ After Shock rocks! Shockers RULE!!! Look for em both @ finals
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