need some quick audio help with 20hm vs 4ohm!

[TOYUTAH]

ok guys i ordered some alpine type s subs for my truck but the 4ohm are backordered... but they have the 2ohm version in stock. I tried to read up on the differences real quick and i was just wondering if going 2ohm will work my amp that much harder to run 2ohm than it would to get the same sound out of a 4ohm sub? hope this makes sense, thanks for any help.

 

[EeePee]

Yeah 2 ohms are a workout compared to 4 ohm. But if your amp is good to 2 ohms, then you're fine, and if you can supply it with the power, it'll be louder. It depends if you're going for stereo, or bridged mono too.

And it depends how many subs you've got as doubling the driver count increases output by 6 decibels. 2 is 6 db louder than 1, 4 is 6 db louder than 2, etc...

My home speakers are 8 ohm drivers, a single driver for the entire frequency range, and I power them with 2A3 tubed monoblocks I built that put out a whopping 3 amps if I'm lucky. But because the drivers are so sensitive, I can blast em so loud I can't take it.

As the old saying goes, if you can't get the first watt right, why bother with more than one.

I drifted off topic.

 

[Offroader5]

It depends on your amp. *Most* amps are capable of running in 2 ohm STEREO mode. This would be using a 2 channel amp with each channel powering
one 2 ohm sub + to + & - to -. This is 2 ohm stereo. Same as 4 ohm stereo...but of course the different impedance at the voice coils.

If you are only going to run one sub however...and choose a 2 ohm single voice coil sub, the amp may not be capable of running it. If you had the same 2 channel amp bridged to mono for one channel, and then hooked that one channel up to the single 2 ohm sub...now you're talking 2 ohm mono, and not all amps can do this without going thermal.

2 ohm is more efficient than 4 ohm. (more efficient at using the power fed to it by the amp).

 

[EeePee]

I had a really old Phoenix Gold amp, like a MPS 224 or something, direct competition for an Orion 2x25 watter. The PG was 2x24 but could do like a 1/4 ohm load and power doubled every halving of impedance. That thing was sweet.

I see Rodin owns PG now...

 

[TOYUTAH]

these subs are dual voice coil, right now i have a eclipse 660 watt amp (i believe, ill have to go check) running two alpine type e 10's bridged. theyre single voice coil... ill run out and see what my amp says. oh and i plan on running two of these new type s's

*edit* the amp is a eclipse pa4212, it doesnt say wattage or anything just 2/1 channel, ill see if i can find out more

 

[Offroader5]

I had a really old Phoenix Gold amp, like a MPS 224 or something, direct competition for an Orion 2x25 watter. The PG was 2x24 but could do like a 1/4 ohm load and power doubled every halving of impedance. That thing was sweet.

I see Rodin owns PG now...

I used to have an old M25. That thing was wayyyy bang for your buck. Same deal, it was "rated" at 2x25, but put out closer to 2x75 @ 4 ohms. Put out close to 1000 watts at 1/4 ohm mono :shock:

 

[Offroader5]

these subs are dual voice coil, right now i have a eclipse 660 watt amp (i believe, ill have to go check) running two alpine type e 10's bridged. theyre single voice coil... ill run out and see what my amp says

Dual voice coils complicates it even more.

You'd treat each voice coil like it was it's own sub. So if you now have 2 single voice coil subs and buy 2 dual coil subs, then you would need to figure your impedance as if you have 4 single coil subs. Make any sense ;-)

 

[rottenbelly]

You can wire them up to 4 ohms if they are single voice coil 2 ohm speakers. If your amp isnt 2 ohm stable it will eventually hurt it. Check out the12volt.com for wiring diagrams. It will explain everything way better than i can tell you.

 

[TOYUTAH]

thanks for all the help guys! so how do i know if my amp will be able to handle the load?

 

[Chadworkz]

Look up the specs for it and see if it is 2ohm stable...but most likely it is. What brand and model amp is it?

 

[EeePee]

This it?

http://www.woofersetc.com/index.cfm?fuseaction=product.display&product_id=214

 

[Offroader5]

these subs are dual voice coil, right now i have a eclipse 660 watt amp (i believe, ill have to go check) running two alpine type e 10's bridged. theyre single voice coil... ill run out and see what my amp says. oh and i plan on running two of these new type s's

*edit* the amp is a eclipse pa4212, it doesnt say wattage or anything just 2/1 channel, ill see if i can find out more

The 4212 is not stable at 2 ohm MONO...but will be fine with a 2 ohm STEREO load.

 

[TOYUTAH]

This it?

http://www.woofersetc.com/index.cfm?fuseaction=product.display&product_id=214

yep thats it! sorry guys im a total newb with this stuff but whats your oppinion... should i just take the 2ohm or what for the 4ohm? or even just get a different sub? (needs to be farely shallow to fit behind my crew cab seat) thanks a ton guys i appreciate it!

 

[4u2nv]

If the speakers are 2 ohm dual voice coil you can wire each speaker to be 4 ohms by running both coils in series on each sub this would give your amp a 4 ohm load in stereo (one 4 ohm sub to each channel) It is a two channel amp right? If it's a mono amp this won't work.... unless it's 2 ohm stable like everyone else said.

 

[TOYUTAH]

well i decided to just have them send the 2ohm and ill probably just buy a different amp, might as well upgrade it all right?

 

[axman2010]

All I know is that lower ohm is more efficent and what your amp is capable of will determine what you can run. My dad had a tahoe with 6 12's running at 0ohm with 3400 continuous watts!!:shock::shock::shock: it was insane he took second at the competition he entered 152db

 

[TOYUTAH]

can you guys recomend a good amp close to $300 or less that i can run both of these subs off of?

 

[AWILLIAMS64]

if you have any questions pm or get me on yahoomessenger, awilliams642001 . I installed professionally at a custom shop for over 15 years, i can walk you thru it. I have a jl audio amp listed in the for sale section that would work nicely with these.

 

[JaynDrea]

I was going to say you can PM me as well but AWILLIAMS64 beat me to it. I have worked in a custom shop for 10 years. The amp you have will run those two Alpines just fine. But there are other options out there and better in my opion. So, if you need any help, just ask...

Jason West

 

[cartronicshn]

If you are looking for shallow mount type woofers, i would recomend RF P3 dual voice coil at 4ohm and then you can run 2ohm stereo and still have room for amp improvement later down the road8), RF website is down at the moment, i will link you later for specs on the woofer.
10" are 300 watts rms 45hz-250hz
12" are 400 watts rms 43hz-250hz