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Question about box rise / impedance rise


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Hi guys i am currently running 2 D1 Zv5 15's on a SCV-6000D wired down to 1 ohm.

My question is say i have box rise / impedance rise to like 2 ohms or more ect if i was to wire the sub separately to two different amp the put's out 3k at 2 ohms as can only wire the subs down 2 ohms would this negate the rise or would it mean it would just increase the rise to say 3 ohms or more ect the amps i been looking at are the T2500-1bdCP.

Or the other thing would be to get two 3k amps and wire them to .5 but not to sure which would work better as it is end of the competition season where i live next week so looking to do some upgraded over the winter.

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So impedance rise is basically a multiplier of the DC resistance that varies with frequency.  Impedance can never be lower than DC resistance, but it can come very close to being equal with it.  WIth your subs wired together for a 1 ohm nominal load to your amp, lets assume your DC resistance (as measured with a DMM) is 1.1 ohms.  At your tuning frequency (where impedance is generally the lowest) it may be 2.2 ohm, for a multiplier of 2.0.  If you were to wire all your coils in series for a 4 ohm nominal load (DCR of 4.4 ohms) your impedance at tuning would probably be around 8.8 ohms.  At frequencies other than your tuning, impedance is going to be higher, much higher.  

So with your current setup, if you were to switch to two 3000 watt amps and wired one sub to each at .5 ohm nominal, that would probably work very well and each amp would see a minimum of roughly a1 ohm load when in use.  

Since we are on the topic of impedance, I'm going to get on my soapbox for a minute.  Impedance is not correlated with output!  If your system causes your impedance to rise enough that you can wire a lower load to your amp, that's great and will be to your benefit.  However all to often I see people asking how to lower their "box rise" thinking that will get them more output since they assume their amp will then be putting out more power.  That may or may not be the case.  Higher impedance is neither good or bad, what matters is why it is being raised.  I know this isn't what you are asking about, but I like to take every opportunity to get this message out.   

"Nothing prevents people from knowing the truth more than the belief they already know it."
"Making bass is easy, making music is the hard part."

Builds:

U7qkMTL.jpg  LgPgE9w.jpg  Od2G3u1.jpg  xMyLoO1.jpg  9pAlXUK.jpg

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52 minutes ago, Triticum Agricolam said:


Since we are on the topic of impedance, I'm going to get on my soapbox for a minute.  Impedance is not correlated with output!  If your system causes your impedance to rise enough that you can wire a lower load to your amp, that's great and will be to your benefit.  However all to often I see people asking how to lower their "box rise" thinking that will get them more output since they assume their amp will then be putting out more power.  That may or may not be the case.  Higher impedance is neither good or bad, what matters is why it is being raised.  I know this isn't what you are asking about, but I like to take every opportunity to get this message out.   

Very interesting, can you elaborate on that?  I always assumed that lower impedance, less resistance, more power output, more volume.  

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For some visual depictions: 

 

Chevy Sonic Wall (4) 15's on 10k Build Log

https://www.stevemeadedesigns.com/board/topic/209412-2015-chevy-sonicwall4-15s10klithiumlarge-case-hairpin-us-alts/

(4) Fi SP4 15's | (2) Ampere 5Ks | Active! | Arc KS600.2 & KS125.2mini | CDT Silk Domes | Silver Flute 8s | 240Ah JY | US Alts

Jeep Wrangler JK (4) 8's in a 4th Order Build Log

https://www.stevemeadedesigns.com/board/topic/209841-shadow-2016-jeep-wrangler-jk4th-order4-8sdc-35klarge-case-hairpin-us-alts/

IG @walledsonic

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5 hours ago, mestapho said:

Very interesting, can you elaborate on that?  I always assumed that lower impedance, less resistance, more power output, more volume.  

The WalledSonic linked to has lots of good info. 

So more power doesn't always equal more output.  For example, let assume you have two identical 15" subs.  You put one in a 3 net cu ft box and one in a 4 net cu ft box.  Both are tuned to 32 Hz.  You have both subs wired in parallel to the same amp so they both will receive equal voltage.  Around the tuning frequency, the 4 cu ft box is going to have more output than the 3 cu ft box.  However the 4 cu ft is going to be receiving less watts since when you make an enclosure larger it raises the impedance.  

"Nothing prevents people from knowing the truth more than the belief they already know it."
"Making bass is easy, making music is the hard part."

Builds:

U7qkMTL.jpg  LgPgE9w.jpg  Od2G3u1.jpg  xMyLoO1.jpg  9pAlXUK.jpg

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