Couple of ohm load and impedance rise questions...

[bunkerking09 10+ year member]

Ok, had a few questions that I thought of, they kind of coincide with each other so bear with me on these...

1. Impedance rise from the box, how can you fight this? I've heard a larger box, more batteries (just better electrical I'm guessing).

2. Lets say you have an amp wired to .5 ohms, but your getting 2 ohms after box rise. So would this be be like you are running the amp @ .5 or 2 ohms? A confusing question I know...i'm confused as well //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

Reason being, I have two D2 subs, so should I just wire it to .5 and expect less power due to box rise?

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[KHARPS 10+ year member]

in for the answer

 

[bunkerking09 10+ year member]

in for the answer

i'm thinking about starting a smaller forum just or rangers and car audio...i'll hit ya up if it goes down //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Rashaddd 5,000+ posts]

impedence rise isn't always bad, its actually good in almost any case in terms of SPL

say you have a sub wired at 1 ohm, but when you play a sweep you have dips down to .5 ohm, and peaks up to 40 ohms

The real amount of power your system is supplying at these varying frequencies changes, even though the 'apparent' amount, or what it seems like your sub is getting, does not for the most part. So in that case, you could either have the sub down at 1 ohm at a certain frequency, pulling 4kw out of your amp for example, or have that same amp only have to pull 100 real watts when imp rise goes up to 40 ohms on another frequency, meanwhile you get basically the same real output from the sub

idk if this makes sense...and most of the time especially in daily setups its not this extreme, but that is what happens. In free air, you will **** the least real power at Fs, and get the most real output.

 

[bunkerking09 10+ year member]

impedence rise isn't always bad, its actually good in almost any case in terms of SPL
say you have a sub wired at 1 ohm, but when you play a sweep you have dips down to .5 ohm, and peaks up to 40 ohms

The real amount of power your system is supplying at these varying frequencies changes, even though the 'apparent' amount, or what it seems like your sub is getting, does not for the most part. So in that case, you could either have the sub down at 1 ohm at a certain frequency, pulling 4kw out of your amp for example, or have that same amp only have to pull 100 real watts when imp rise goes up to 40 ohms on another frequency, meanwhile you get basically the same real output from the sub

idk if this makes sense...and most of the time especially in daily setups its not this extreme, but that is what happens. In free air, you will **** the least real power at Fs, and get the most real output.

i'll read this about 15 more times and i'll let ya know if i make any sense out of it.

i'm sure its legit though //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[KHARPS 10+ year member]

i'm thinking about starting a smaller forum just or rangers and car audio...i'll hit ya up if it goes down //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Sounds like a great idea! I read something on here about Ford charging to do that though???

 

[Rashaddd 5,000+ posts]

For example, when I'm testing subs in my room, my lights dim off approx 400 watts on average. I can pull more like 800+ (rated watts, measured by voltage) at Fs (say 30hz) and not have the lights dim at all, and then just switch to a lower (say 20hz) or higher (say 50hz) tone and the lights dim like hell and my powersupply goes into protection...meanwhile the sub isn't being run any harder, it's just dropping impedence and thereby pulling closer to a real 800 watts which my powersupply/room can't handle. It also means the coil is going to heat up more due to the increase of current, again with no increase in actual output from the sub.

 

[bunkerking09 10+ year member]

starting to make sense...

 

[AudioXtremes 10+ year member]

Is this for a spl application? Or for daily?

 

[bunkerking09 10+ year member]

Is this for a spl application? Or for daily?

daily for now. I'm done competing, i don't have to time or money to tune and test everyday

 

[Rashaddd 5,000+ posts]

In general, unless you know what you're doing and can pay attention well and look out for signs that its no good, don't wire below stability or over rated sub power and depend on imp rise to make it just fine. It can work, but its also very likely you'll either overpower your subs or fry the amp.

For burps this can be just fine, as you generally are loudest at a really efficient freq with your box, and the most efficient freq have the highest imp rises for the most part.