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View Full Version : 2 vs. 4 ohm coaxial



bnsf36burton
06-14-2006, 05:10 PM
in a coaxial speaker, is there any difference in sound quality between 4 and 2 ohm speakers when hooked up to only a head unit, and what would the problems be with a 4 ohm output hooked up to a 2 ohm speaker and visa versa

alphakenny1
06-15-2006, 12:21 AM
well i dont think most HU are 2 ohm stable. but if hooked up to an amp in stereo, obviously the 2 ohm speakers will get louder. but if let's say is there an sq difference between a 2 ohm speaker and a 4 ohm speaker and both speakers are getting the same amounts of power, there isn't a difference in sq.

CHIT0WNZHUSTLA
06-15-2006, 12:25 AM
yes there is a difference in sq there is less distortion at 4ohm then there is at 2ohm...

AllStar1500bd
06-15-2006, 12:28 AM
yes there is a difference in sq there is less distortion at 4ohm then there is at 2ohm...Wrong.

The only difference would be the amount of power your HU would be giving them, but not many HU's are 2 ohm stable. Ohms Law FTW.

Gary S
06-15-2006, 02:25 PM
I'd echo the above responses...

- unless the head unit actually has published ratings for 2 ohm, you have a high risk of burning up the head unit amps if you hook up 2 ohm speakers.

- if an amp can handle it, a two ohm speaker, everything else being equal, will have more SPL and midbass.

- the distortion from an amplifier playing at 2 or 4 ohms is a non issue... the best speakers in the world are 2 - 3 % distortion and would completely mask any sound of the amplifier. The only issue is whether or not the amp can handle the load.

bnsf36burton
06-15-2006, 03:17 PM
alright....i was wondering because im thinking about getting either a pioneer p4700mp, p4800mp, or a premier p470mp....and was wondering if there would be any complications with infinity 652.7i speakers which were 2 ohms and the premeir h/u puts out 4 ohms so should i just get the pioneer p4800mp because its 2 and would go better with the speakers or get the premier if it would sound about the same only just have different ohm outputs....i guess?

adam71
06-15-2006, 03:52 PM
the best speakers in the world are 2 - 3 % distortion and would completely mask any sound of the amplifier. The only issue is whether or not the amp can handle the load.

I don't know of any class a/b amps that aren't stable at 2ohm stereo/4 ohm mono.

Fast1one
06-15-2006, 03:54 PM
Just buy an amp for the speakers....HU power is teh sux0r anyway....

Gary S
06-15-2006, 04:05 PM
As above, if it's not rated at 2 ohms, the CD player might not handle it. You could always call pioneer and ask though.

Your best bet would be to go with a subwoofer/satellite system... they are the basis for all great sounding cars.

If cost is an issue, get the cheapest CD player with the features you need, then:

1) You can get a 4 - channel amp with built in crossovers around $50

2) Blowout subs that will handle 150 watts each with excellent sound quality for $15 each at Credencespeakers.com - same as kickers (they make and/or have made Kicker)

3) I'm sure you can find a box for around $40.00 or less.

= total extra cost (not including shipping,tax, and labor) of $105.00 if you only use one sub and sell the other... in fact you could make money selling the second sub (they sell them in pairs)

The system I described, even with a 15 watts X 4 amp will be at least 6 - 10 db or more SPL when you use the crossovers in the amp, not to mention much clearer... it would sound ten times better than trying to squeeze a couple more measly full-range watts from a little head unit.

One of the first budget systems I had back in 1984 was an Alpine head unit, active crossover, 2 - two X 15 watt alpine BTL amps in the glove box, a set of coaxes in the doors, and 6X9 Alpine subs in the rear deck... it was the first subwoofer/satellite system my installer had ever heard... he could not believe how powerful and clean it sounded with two of those tiny little amps... he had never heard anything like it.

And it's simpler and cheaper to do today... back then, there were not many 4 channel amps, and even fewer with built-in crossovers.

bnsf36burton
06-15-2006, 04:53 PM
would i want 4 or 8 ohm subs and do i need a whole extra amp for them or just run the infinity's and the subs off the 4 chanel and n leave the rear ones hooked up to the headunit

Gary S
06-16-2006, 05:16 PM
would i want 4 or 8 ohm subs and do i need a whole extra amp for them or just run the infinity's and the subs off the 4 chanel and n leave the rear ones hooked up to the headunit


You can run the rears off the head unit

Front Infinity's off the front two amp channels.

You could use a separate class d amp for subs ... assuming you use two subs, if it's rated at 2 ohms, you need 2 - four ohm subs. You would be able to up your power with separate amps, but it will also increase cost.

If it's a four channel amp, rated for 2 ohms, you can bridge the two rear channels and run 2 - eight ohm subs (total ohm speaker load would be 4 ohms, and because the amp is bridged, each channel "sees" 2 ohms).

2 - four ohm subs wire in Parallel = 2 ohms

2 - eight ohm subs = 4 ohms.

What you will have to figure out in your shopping travels is 1) total ohm load of subs, and 2) The lowest ohm load the amp you are looking at can handle.


Also, don't count out 5- channel amps if you can find a deal.

A good place to find discount and refurbished amps is ikesound.com ... search viper, orion, dei, ppi, and refurb. - they had a directed/DEI 5-channel 650 watter listed for $100.00 Also, webzone had some refurb kenwoods, I don't know how good a deal they are though. I'm also sure there are a lot of good deals you could find across the web.

bnsf36burton
06-17-2006, 12:38 PM
i really dk if i have the money for all that yet though....maybe just get a h/u.....a good pair of speakers for the front n a decent pair for the back n add the rest on at the end of the summer?

squeak9798
06-17-2006, 04:31 PM
I don't know of any class a/b amps that aren't stable at 2ohm stereo/4 ohm mono.

Eclipse 34230.

Only stable to 4ohms per channel, and not bridgeable.

;)

adam71
06-17-2006, 06:29 PM
Eclipse 34230.

Only stable to 4ohms per channel, and not bridgeable.

;)

Touche'.;) But I think you would agree those types of amps are in the minority.

squeak9798
06-17-2006, 11:34 PM
Touche'.;) But I think you would agree those types of amps are in the minority.

Indeed, indeed.