CJ18 Posted September 17, 2012 Report Share Posted September 17, 2012 (edited) That only tells you what your box rise is at 1 frequency though. That is great if you are competing and do burp only, but how does that help you in a daily setup? Now do the same test from 25-65hz in 5hz increments and then you will have useful info. edit: Damn jetta ninjaed me. I was nicer though! I love this part "when it fluctuates you're better off letting a damn monkey throw a dart at a poster board with random numbers written on it for your rise" Edited September 17, 2012 by CJ18 Quote Link to comment Share on other sites More sharing options...
Jman08 Posted September 17, 2012 Report Share Posted September 17, 2012 (edited) That only tells you what your box rise is at 1 frequency though. That is great if you are competing and do burp only, but how does that help you in a daily setup? Now do the same test from 25-65hz in 5hz increments and then you will have useful info. edit: Damn jetta ninjaed me. I was nicer though! I love this part "when it fluctuates you're better off letting a damn monkey throw a dart at a poster board with random numbers written on it for your rise" i understand that its just to get an idea man never had a problem out of my amp being wired at .5 ohm.. Edited September 17, 2012 by Jman08 Quote Youtube.com/J Hutch22 Link to comment Share on other sites More sharing options...
ALPINE408 Posted September 17, 2012 Report Share Posted September 17, 2012 (edited) lol soooooooooo you cant explain it to me? then is that why your getting mad cause you don't know and i was right? its very easy to tell someone what they don't know by comments like that.... if you understood anything about ohm rise you would of never said what you did Clamp and multi meter i just burp my peak freq and divide..dont like that you just assume i have no idea about the concept thats all lol thanks for proving my point incase you need help on my point you do not have a concept of it at all soo go ahaead and tell people the false info of your ohm rise will be over 1 ohm and your good Edited September 17, 2012 by Team Bassick (ALPINE) Quote Have you ever had your woofers blown? Link to comment Share on other sites More sharing options...
CJ18 Posted September 17, 2012 Report Share Posted September 17, 2012 Just an idea isnt useful info though when you are talking about wiring below 1 ohm. Most amps are 1 ohm stable. What this means is if they see much below 1 ohm reactive then they will go into protect. Your actual reactive impedance is going to be much lower on the lower notes than it is at your peak frequency. Here is an example for you from a clamp test I did on my 7.5k. Here are the rated specs for the 7.5k. Features Voltage 7.5kw Output Power (RMS) at 4 ohm 14.4V 2200W x 1 at 2 ohm 4400W x 1 at 1 ohm 7500W x 1 at 1 ohm 16V 8600W x 1 at 1 ohm 18V 9200W x 1 This test was done in my 2006 Ford F150. I am running 1 Mike Singer 350a alt charging my 5 XS D1400 14v batteries at 16.4v Voltage started at 16.4v. Starting impedance is .67ohms HZ----AMPS----VOLTS----WATTS----OHMS----Voltage Drop 30----.9----96.5----7806.85---1.19----15.2v 35----78.2----100.2---7835.64---1.28----15.2v 40----72.2----103.6---7479.92---1.43----14.1v 45----62.2----107.8---6705.16---1.73----14.7v 50----61.5----106.9---6574.35---1.74----14.7v My starting Impedance was .67 ohms. As you can see, the lower hz of the tone played, the lower my rise was. Now consider that my peak frequency in my truck is 48hz. At 50hz, I have 1.1ohms of rise from .67 to 1.74. Of course I am going to be fine here, but down at 30hz, I was only rising from .67 to 1.19. Now if I were to drop back and be wired to .5 ohm and saw the exact same numbers, at 30hz I would be at 1 ohm reactive, but what about a lower note? I may have only seen .85 reactive at 25hz and either sent the amp into protect, or could have possible blown the amp. This is why all of these numbers are useful for a daily driver if you want to run below 1 ohm. Quote Link to comment Share on other sites More sharing options...
97Jetta1637 Posted September 17, 2012 Report Share Posted September 17, 2012 That only tells you what your box rise is at 1 frequency though. That is great if you are competing and do burp only, but how does that help you in a daily setup? Now do the same test from 25-65hz in 5hz increments and then you will have useful info. edit: Damn jetta ninjaed me. I was nicer though! I love this part "when it fluctuates you're better off letting a damn monkey throw a dart at a poster board with random numbers written on it for your rise" mine was seemingly nice, i just use swear words Quote #teamihop Two 12 inch DC XL's Carbon Fiber Cap Stetsom 7k Shell of box / baffle built by me Port / sealing the box by John Hone Fuck midrange Alpine-9886 http://www.stevemeadedesigns.com/board/topic/177428-97jettas-sql-trunk-wall-loudest-99-buick-century-custom-with-a-one-legged-owner/ price has no influence on how something sounds I told him to move the fucking port. they see me hoppin they stoppin they can't believe im so white and dirty It looks like you got so drunk, that someone came up and stole your leg. Link to comment Share on other sites More sharing options...
ALPINE408 Posted September 17, 2012 Report Share Posted September 17, 2012 Just an idea isnt useful info though when you are talking about wiring below 1 ohm. Most amps are 1 ohm stable. What this means is if they see much below 1 ohm reactive then they will go into protect. Your actual reactive impedance is going to be much lower on the lower notes than it is at your peak frequency. Here is an example for you from a clamp test I did on my 7.5k. Here are the rated specs for the 7.5k. Features Voltage 7.5kw Output Power (RMS) at 4 ohm 14.4V 2200W x 1 at 2 ohm 4400W x 1 at 1 ohm 7500W x 1 at 1 ohm 16V 8600W x 1 at 1 ohm 18V 9200W x 1 This test was done in my 2006 Ford F150. I am running 1 Mike Singer 350a alt charging my 5 XS D1400 14v batteries at 16.4v Voltage started at 16.4v. Starting impedance is .67ohms HZ----AMPS----VOLTS----WATTS----OHMS----Voltage Drop 30----.9----96.5----7806.85---1.19----15.2v 35----78.2----100.2---7835.64---1.28----15.2v 40----72.2----103.6---7479.92---1.43----14.1v 45----62.2----107.8---6705.16---1.73----14.7v 50----61.5----106.9---6574.35---1.74----14.7v My starting Impedance was .67 ohms. As you can see, the lower hz of the tone played, the lower my rise was. Now consider that my peak frequency in my truck is 48hz. At 50hz, I have 1.1ohms of rise from .67 to 1.74. Of course I am going to be fine here, but down at 30hz, I was only rising from .67 to 1.19. Now if I were to drop back and be wired to .5 ohm and saw the exact same numbers, at 30hz I would be at 1 ohm reactive, but what about a lower note? I may have only seen .85 reactive at 25hz and either sent the amp into protect, or could have possible blown the amp. This is why all of these numbers are useful for a daily driver if you want to run below 1 ohm. you can't forget the fact that everytime the sub stops it drops to (in your case) .67 ohms then rises from that point so in daily your amp will see .67 ohms a lot of the time Quote Have you ever had your woofers blown? Link to comment Share on other sites More sharing options...
Jman08 Posted September 17, 2012 Report Share Posted September 17, 2012 lol soooooooooo you cant explain it to me? then is that why your getting mad cause you don't know and i was right? its very easy to tell someone what they don't know by comments like that.... if you understood anything about ohm rise you would of never said what you did Clamp and multi meter i just burp my peak freq and divide..dont like that you just assume i have no idea about the concept thats all lol thanks for proving my point incase you need help on my point you do not have a concept of it at all soo go ahaead and tell people the false info of your ohm rise will be over 1 ohm and your good said "i would wire it to .5 ohms more than likely you will be over 1 0hm after rise..or would at least test it out"... Yes i do know how to caculate rise and do have a concept of it. Reason why i clamped using the peak frequency is because i wanted to see how much power my amp was putting out at my highest termlab score..could of tested it on music but could care less. Quote Youtube.com/J Hutch22 Link to comment Share on other sites More sharing options...
SnowDrifter Posted September 17, 2012 Report Share Posted September 17, 2012 Put my system in at .5 and everything is fine voltage is the same as 1ohm, amp gets Luke warm after about 10-15mins. So I guess the optima yellow top is fine for 1200 watts. 2 weeks later... 2 Quote ~~~~~~~~SAY NO TO PHOTOBUCKET~~~~~~~~ Snow's DD-1 tracks here: https://www.stevemeadedesigns.com/board/topic/167433-snows-dd-1-tracks/ My take on OFC vs CCA: https://www.stevemeadedesigns.com/board/topic/110381-things-that-piss-you-off-in-the-car-audio-world/?do=findComment&comment=2461444 Link to comment Share on other sites More sharing options...
tacomaguy1 Posted September 17, 2012 Report Share Posted September 17, 2012 lol at how against everyone here is about running an amp at .5 Quote Team Flex Issues Link to comment Share on other sites More sharing options...
fox_racin4 Posted September 17, 2012 Report Share Posted September 17, 2012 i have my 4500s at .46ea daily... buttttt i know they can blow up at any time.. and i have the electrical to back it Quote 1998 gmc extd cab 12 crossfire C710s 4 SAZ-4500s 3 Singer 400A altsbuncha mids/highs Team Asshole Link to comment Share on other sites More sharing options...
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