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View Full Version : Disadvantages of using 2 ohm speakers



AConnelly09
10-23-2012, 08:25 PM
I am looking to buy new speakers and an amp to run them, with low budget a main priority. While looking, I came across these Infinity Reference 6.5's that are 2 ohm.

http://www.amazon.com/Infinity-Reference-6032cf-6-5-Inch-High-Performance/dp/B002BZFSYA/ref=sr_1_1?ie=UTF8&qid=1351034221&sr=8-1&keywords=infinity+reference

So I'm thinking I'm just going to get 2 sets of these, allowing me to get away with a cheaper amp since it only needs to power the speakers at 2 ohms. Are there any cons to this that I am overlooking?

I was planning on matching these with an MB Quart FX4.50

Dirtrider4eva
10-23-2012, 08:26 PM
little more distortion, aka less clarity. usually all i can think of.

AConnelly09
10-23-2012, 08:31 PM
little more distortion, aka less clarity. usually all i can think of.

I plan on being relatively conservative on the gains. Is it really noticeable at reasonably loud volumes? I'm not going to be maxing them or anything but I would like it to be able to turn up decently loud.

Dirtrider4eva
10-23-2012, 08:33 PM
I plan on being relatively conservative on the gains. Is it really noticeable at reasonably loud volumes? I'm not going to be maxing them or anything but I would like it to be able to turn up decently loud.

couldnt tell you. ive never ran anything under 6ohm for door speakers. ive heard its barely noticeable from 4ohm to 8 0hm. but every little bit helps. IMO. id rather run 4ohm or higher components that are more sensitive (less power needed). you can still get the same loudness and keep up the SQ on less power

zako
10-23-2012, 09:51 PM
In general, I would prefer not to run the front speakers at 2ohm. Why? If you use a Class A/B amplifier, which normally run pretty hot when driven long and hard, it will run even hotter with 2ohm impedance.

The second issue is that the MB Quart FX amps are not particularly great amps. They do about 2/3 of the rated power power at 4ohm, and I can only guess what will happen if you run it at 2ohm (not with respect to rms watts, but overall stability). My advise is not to go cheap on amplifiers. Speakers can come and go as people's tastes become more sophisticated or if they get bored with the sound of the old speaker. If you start with a solid amplifier, it can serve you for a long time. The FX amp looks like something that a demanding enthusiast will want to change pretty shortly. If you want a recommendation, I'd recommend something like PPI Black Ice amplifier, such as Precision Power PPI BK520.4, or PPI's slightly lower end Sedona amplifier line, or the discontinued Boston Acoustics GT-475 (the later are supposed to be pretty high end, but you can find them for well under $200 as they have been discontinued). Another solid amplifier is MB Quart REF4 series. These have been discontinued, but you can find the REF4.50 and REF5.80 pretty cheaply. These provide a bit more power than rated. In any case, an average car audio speaker will sing fine on 50watts RMS power. I have seen "110rms watt" speaker bottom out with 60watt RMS power unless high pass filter is set sufficiently high, well above 100Hz. Any any case, even with the REF4 amp running a low impedance speaker could be a concern. I run 4ohm active front stage in mine, and it still gets very hot, specially with cargo in the trunk obstructing its airflow.

Having said that, Infinity speakers are not true 2ohm speakers. They really are 2.7-3ohm speakers, and Infinity claims that the final impedance is close to 4ohm if you continue to use flimsy factory wiring.

AConnelly09
10-24-2012, 03:10 AM
In general, I would prefer not to run the front speakers at 2ohm. Why? If you use a Class A/B amplifier, which normally run pretty hot when driven long and hard, it will run even hotter with 2ohm impedance.

The second issue is that the MB Quart FX amps are not particularly great amps. They do about 2/3 of the rated power power at 4ohm, and I can only guess what will happen if you run it at 2ohm (not with respect to rms watts, but overall stability). My advise is not to go cheap on amplifiers. Speakers can come and go as people's tastes become more sophisticated or if they get bored with the sound of the old speaker. If you start with a solid amplifier, it can serve you for a long time. The FX amp looks like something that a demanding enthusiast will want to change pretty shortly. If you want a recommendation, I'd recommend something like PPI Black Ice amplifier, such as Precision Power PPI BK520.4, or PPI's slightly lower end Sedona amplifier line, or the discontinued Boston Acoustics GT-475 (the later are supposed to be pretty high end, but you can find them for well under $200 as they have been discontinued). Another solid amplifier is MB Quart REF4 series. These have been discontinued, but you can find the REF4.50 and REF5.80 pretty cheaply. These provide a bit more power than rated. In any case, an average car audio speaker will sing fine on 50watts RMS power. I have seen "110rms watt" speaker bottom out with 60watt RMS power unless high pass filter is set sufficiently high, well above 100Hz. Any any case, even with the REF4 amp running a low impedance speaker could be a concern. I run 4ohm active front stage in mine, and it still gets very hot, specially with cargo in the trunk obstructing its airflow.

Having said that, Infinity speakers are not true 2ohm speakers. They really are 2.7-3ohm speakers, and Infinity claims that the final impedance is close to 4ohm if you continue to use flimsy factory wiring.

Thanks for that insight. What 6.5s would pair good with the Precision Power PPI S320.4?

I was thinking about these cause they are on sale + free shipping http://www.soundqubed.com/SDC-65TX-Sold-As-Pair_p_145.html

AConnelly09
10-25-2012, 04:40 PM
BUmp

butterMilk
10-25-2012, 05:03 PM
Honestly those speakers probably ****.

zako
10-25-2012, 06:21 PM
I honestly have no idea which coaxial speakers sound good. Try Pioneer D-series I guess. If you can afford it, JL Audio has a coaxial version in the C3 and C5 lines. These should be a level above >99% of coaxial speakers you can find.

Another interesting coaxial speaker is Massive Audio CK6III/CK6V/CK6 X. These are convertible between component and coaxial install. Expect good SPL, good bass. They do need a bit more power than average.

AConnelly09
10-25-2012, 08:43 PM
Honestly those speakers probably ****.

What makes you say that?


I honestly have no idea which coaxial speakers sound good. Try Pioneer D-series I guess. If you can afford it, JL Audio has a coaxial version in the C3 and C5 lines. These should be a level above >99% of coaxial speakers you can find.

Another interesting coaxial speaker is Massive Audio CK6III/CK6V/CK6 X. These are convertible between component and coaxial install. Expect good SPL, good bass. They do need a bit more power than average.

I will look into that.

e/ I wasn't really looking for components. I don't have factory tweeters and I don't have the skills/tools to install them in the A pillars or glass them somewhere, so I was just gonna run components.

I'm under the impression that at this point all coax's in the generally cheaper price range are about the same. I've always heard good things about AQ and I bought my buddy an hdc315 which bangs so i'm hoping they have good speaker quality also.

butterMilk
10-26-2012, 06:16 AM
Honestly I say that only on the price of the speakers. Ive never had a pair of 40$ speakers impress me.

SMS
10-26-2012, 06:50 AM
Look into CDT they have some really good coaxs for $100 on woofers ect.

AConnelly09
10-26-2012, 05:15 PM
Honestly I say that only on the price of the speakers. Ive never had a pair of 40$ speakers impress me.

They are on sale from 69.99 so I'm assuming they are about that quality (which is fine with me)

I plan on running them off my head unit for the first part, then I'll eventually buy a 4 chan and amp them. They don't need to be anything crazy.

SMS - I'll check them out, thanks