# ? Can most 2 ohm mono amps handle 1.5 ohm daily, or is 1ohm mono required?



## newtitan (Mar 7, 2005)

Hey all I have a few drivers that read 1.5 ohm off the multimeter when the coils are wired up

hence my question, can most 2 ohm mono amps, handle a 1.5 ohm load daily, or do I have to go down to 1 ohm

thanks


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## t3sn4f2 (Jan 3, 2007)

Depends on you, the amp, and the impedance of the sub in the passband you are using it at.


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## fastlane (Apr 6, 2009)

Keep in mind that the ohm load fluctuates. A 2ohm sub is really never putting out exactly 2 ohms (except sitting on the test bench ). So if your subs are wired for 1.5 ohm, they could easily dip into the 1ohm range during use. 

What amp are you running?


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## GregU (Dec 24, 2008)

newtitan said:


> Hey all I have a few drivers that read 1.5 ohm off the multimeter when the coils are wired up
> 
> hence my question, can most 2 ohm mono amps, handle a 1.5 ohm load daily, or do I have to go down to 1 ohm
> 
> thanks


A 1.5 ohm reading on the DMM is probably a 2 ohm load.


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## t3sn4f2 (Jan 3, 2007)

GregU said:


> A 1.5 ohm reading on the DMM is probably a 2 ohm load.


x2, and higher when you hammer it which is where the question matters.


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## dubbreak (May 9, 2008)

GregU said:


> A 1.5 ohm reading on the DMM is probably a 2 ohm load.


Yeah.

And if you amp can't deal with a 1.5 ohm load then it definitely won't like a 1ohm load.

If the subs are rated at 4ohms and you are running them in parallel then it's probably a 2ohm nominal load. The DMM is just measuring DC resistance. In reality the impedance (measured in ohms) is a function over frequency (i.e. it varies over the frequency range). In most of the operating range the amp will see a lot higher load than 1.5ohm (at least 2ohm).

Some manufacturers actually post impedance plots. If you really wanted to know you could buy something like the dayton WT3 which will give you full T/S params and a nice graph of the impedance.


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## mikey7182 (Jan 16, 2008)

He may have a pair of dual 6 ohm subs, like the old JLs or the WxxGTi MKII.


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## newtitan (Mar 7, 2005)

darn, lol, I was hoping to get by with one of those PG roadster66 amps before the go bye bye, 

oh well, guess Ill try out a 1ohm mono amp

I have a sw9102 that is dual 3 ohm, that I might as well trow in truck till I trade it in few weeks

anyone know a CLEAN 1ohm mono amp

I have been looking at the jl hd750, but the darn things are so costly for the power output


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## newtitan (Mar 7, 2005)

and yeah I would try my wt3, but it wont install on 64bit Os's, and they refuse to update the install loader for some reason


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## Oliver (Jun 25, 2007)

I'd go with a SPL manufacturer like Sundown - Jacob Fuller 

His amps will handle it.

http://www.diymobileaudio.com/forum/spl-science/68997-new-personal-best-one-sub.html


> *I'd go with a SAZ 2000 D*
> http://www.sundownaudio.com/index.php/products/amplifiers/saz-2000d.html
> 
> This amplifier was designed from the ground up to exceed all consumer expectations. From the huge 1/0 gauge power input terminals to the heavy duty heat-sink, this amplifier is built for power.We do recommend a high output alternator when using the SAZ-2000D model.




If this is your sub [these subs will dig deep and need some serious power to give their all ].



> Please click here to upload an image of the Eclipse Sw9102 TI.
> 
> 
> * Polyether Surround
> ...


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## newtitan (Mar 7, 2005)

cool Ill check them out

never ran one


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## mikey7182 (Jan 16, 2008)

newtitan said:


> darn, lol, I was hoping to get by with one of those PG roadster66 amps before the go bye bye,
> 
> oh well, guess Ill try out a 1ohm mono amp
> 
> ...


You just missed my Fosgate T1500-1bd!  How much power are you looking for?


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## newtitan (Mar 7, 2005)

750-1000, as clean as possible

the driver is Dual 4ohm, but it reads 1.5 when wire up (each coil reads 3 ohm) 
never quite mastered rising impedance with respect to time and output I guess lol


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## GregU (Dec 24, 2008)

newtitan said:


> 750-1000, as clean as possible
> 
> the driver is Dual 4ohm, but it reads 1.5 when wire up (each coil reads 3 ohm)
> never quite mastered rising impedance with respect to time and output I guess lol


You might want to re-read our responses. The conclusion was that you should be fine with your 2ohm amp. If your run a 1ohm mono amp, your not going to take full advantage of it's capabilities, you'll cut the rated power in half because you have a dual 4 ohm sub. You don't have a 1.5ohm sub. If you get a new amp, you want one that's rated at 2ohms, unless it's JL cause they have the RIPS technology. They output the same amount of power from 1.5 - 4ohms.

Don't let the DMM confuse you, if your sub is a dual 4, than it's a dual 4, not a dual 3.


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## newtitan (Mar 7, 2005)

no thats what I surmised, appreciate the detail and breaking it down


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## GregU (Dec 24, 2008)

newtitan said:


> no thats what I surmised, appreciate the detail and breaking it down


I re-read my post and it kind of seemed like I was being an ass, really not the way I was trying to make it sound


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## electroman187 (Oct 21, 2009)

When you read 1.5 ohms on your DMM, that is the lowest possible impedance that your woofer could ever approach(basically like receiving a 0.0001 HZ signal). Pretty much any 4 ohm nominal woofer will have DCR of like ~3.4(or some number less than 4) ohms. Like GregU said, your amp should handle the load


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## Fast1one (Apr 6, 2007)

Impedance =/= DC resistance. 

As stated, your speakers have a nominal IMPEDANCE. This is the lowest resistive value that the amplifiers will generally see. Go off that, never DC resistance.


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## Catman (Mar 18, 2008)

FWIW ...I have ran a 2 ohm (minimum) rated Nak PA400 @ 1.5 ohm for years with no issues. 

>^..^<


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## newtitan (Mar 7, 2005)

GregU said:


> I re-read my post and it kind of seemed like I was being an ass, really not the way I was trying to make it sound


def didnt take it that way lol, 

appreciate all the help guys!!!!


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