2 12'' sub but 2 diff amps?
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=38903
Printed Date: May 15, 2024 at 12:37 AM
Topic: 2 12'' sub but 2 diff amps?
Posted By: mrdragon
Subject: 2 12'' sub but 2 diff amps?
Date Posted: September 10, 2004 at 7:10 AM
Hi guys,
I want to built 2 ported sub 1.75cu each, but my problems is i got 2 amp but they r not the same...diff model and diff make. So guys what do u think i should do????
Cheers :)
Replies:
Posted By: fuseblower
Date Posted: September 10, 2004 at 7:12 AM
It depends on what you are trying to acheive. You can use one to power your subs the the other to power your other speakers if both are not class D amps. You can sell both and buy one nice sub amp or you can just take your pick and use the best amp for your subs and sell the other. Too many options.
Posted By: mrdragon
Date Posted: September 10, 2004 at 7:17 AM
Would u recommend this...
1 12" with 1st amp
1 12" with 2rd amp
Will that work???
Posted By: /R7
Date Posted: September 10, 2004 at 7:59 AM
the only hassle i see is matching both amps to the subs, so that they actually come out sounding the same.
selling the amps and buying 1 class D amp would give you more for your money.
but this way you have a few options to work with.
Posted By: stevdart
Date Posted: September 10, 2004 at 8:10 AM
I know from your other posts that you are trying to work with what you got...so I don't see why not use them both. As long as each one will output the right amount of power to each sub. Use a digital multimeter and set the voltage out to the same value on each one. Each sub would then receive the same power. Make sure they each also get the same input signal...or you can use left input with one and right with the other. This is with the assumption that the two subs are identical? ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: mrdragon
Date Posted: September 10, 2004 at 5:11 PM
Hi Stevdatr, can you show me step by step how to use a digital multimeter to set the voltage for the sub???
Sorry i am new to car stereo.
Thanks :)
Posted By: stevdart
Date Posted: September 10, 2004 at 6:43 PM
Ok, give up the ohm rating of each sub, and the power output at that ohm load for each amp. So I can figure out what the voltage should be.
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: 12-volt_guy
Date Posted: September 10, 2004 at 8:29 PM
Doesn't much matter if all he wants to do is match the output. Just send a steady test tone through each one and set the output voltages the same. No?
Posted By: stevdart
Date Posted: September 10, 2004 at 8:53 PM
No, I don't want the chap clipping his amps. What does he do, come up with a random number?
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: Alpine Guy
Date Posted: September 10, 2004 at 9:14 PM
don't even think about it unless your box has 2 separate chambers separateing the subs, , , otherwise, , follow what others are instructing you to do.
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2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.
Posted By: jeffchilcott
Date Posted: September 11, 2004 at 11:17 AM
what type of subs and amps are you trying to run together? if you can run one amp safely then I would run one. running 2 is just going to add more complexity too the system and more current draw on you charging system
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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place
Posted By: mrdragon
Date Posted: September 11, 2004 at 7:15 PM
Subs.....
2 12" Kicker EX sub 125WRMS @ 4 Ohms each
2 amps...
Kenwood Kac-626 150WRMS BRIDGED @ 4 Ohms stable
Ranger TX-2000 50WRMS + 50WRMS @ 4 Ohms
What i want is to built 2 individual boxs, the reason for it it's beacuse if i combine 2 box(s) together and put in the car when i change the tires it will be too heavy to take it out, also it's a ported system.
Thanks :)
Posted By: stevdart
Date Posted: September 11, 2004 at 8:28 PM
To get the voltage output for 125 watts at 4 ohms, you would adjust gain to an output of 22.36 AC volts. The Kenwood is bridgeable, but is the Ranger? I'll presume you've already checked that out. 125 is the speaker RMS, so you don't want to go any higher than that. I can't see what the bridged specs are on the Ranger amp, but if it is more than 125 watts like the Kenwood you would just adjust to the speaker RMS. If the Ranger output is lower, though, you would go with the lowest of everything you have. 22.36 is voltage into 4 ohms to make 125 watts. Use this JL tutorial to help you go through the steps. You need a CD with a test tone recorded at 50 Hz, preferably a professional recording made for this purpose. The frequency can vary, but must be close to that number, in the range of sub frequencies. Your deck will be at its highest clean output, wherever you have found that to be on the dial. Follow the steps in the tutorial to set gain on each amp. You will test with the probes on the terminals that the subs will be hooked to. If you don't have them already, you will need Y-splitters to send the signal to both amps. ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: mrdragon
Date Posted: September 11, 2004 at 9:36 PM
Stevdart where can i obtain the cd for testing????
can it be download from here????
Lastly let say my Ranger tx-2000 amp when BRIDGED is 100WRMS, at what volts should i set it??? just out of curious how do u work out at what volts to set on the amp say for example my Kenwood amp rated at 150WRMS when BRIDGED???
I also got a EQ should i adjust the band to flat (flat = all the bands r in the middle right?)
Cheers:)
Posted By: stevdart
Date Posted: September 12, 2004 at 8:30 AM
frequency generator. Use Ohm's Law E=sqrt(P*R) where power is the wattage you want to set everything at, that being the lowest RMS you have in the three different things you are dealing with. The Kenwood is rated at 150 but if you connect it to a 125 RMS speaker....what should you set it at? 150 and overpower the speaker, or 125 to match the speaker? To find that the output AC voltage is 22.36.....you use the power you want (125 watts) and multiply it by the other known factor, the ohm load resistance on the amp (4 ohms). That's 500. Find the square root of 500...22.36. Right, all controls to flat, and no bass boost. ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: jeffchilcott
Date Posted: September 12, 2004 at 4:01 PM
i would just sell the 2 amps and buy one decent amp to power both subs that will avoid a lot of hassle from running 2 diffrent amps
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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place
Posted By: stevdart
Date Posted: September 12, 2004 at 5:02 PM
I'm with you on that, Jeff, but I've noticed his posts from the past and I know he is working with what he has available...so I'm working with him on this thing. Not the best thing to do, I know.
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: mrdragon
Date Posted: September 13, 2004 at 6:05 AM
Ok i just download the program called "frequency generator" The only ticked box are....Log Frequency, Show Peak, Draw Amp Scale, Draw Freq Scale. And on the right hand side only Carrier box are ticked and it's set at 1000, Finetune =1000, Amplitude =15000, WaveForm = SINE and 11./22./44.1KHz and lastly AM/FM/PM Trigger Level. Now i have to change the Carrier to 50 and the SINE to 44.1Khz right? What about the rest of the settng ??? btw after i adjust those setting and i try to play there is no sound is that normal or did i do something not correct??? Sorry guys for asking for so much stuffs i am so new to car audio! Cheers :)
Posted By: stevdart
Date Posted: September 13, 2004 at 7:49 AM
The only thing I can tell you about that program is to read the Help file. I used it and got all the info I needed by reading Help. Basically, you type the freq you want into the upper right box, using the sine wave setting. You won't hear sub freqs on a computer unless you have some great sub system on it. Drop down menu allows you to press "record now" when you want to start the recording, and "stop recording" when you want to finish it. Make the files as long as you want. Save to your hard drive as .wav file (big files...have some room). Finally, when you've recorded enough to make a CD, use whatever program you use and select the saved files. I used Roxio Easy CD Creator.
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
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