2ohm Vs 4ohm

[shaneyoung82 10+ year member]

I have a Alpine M650 Amp I want to buy an Alpine Type R 12" Subwoofer. I want to know 2 OHM VS 4 OHM.

I have had a bad experience w/ 2 OHM in the past w/ them not working/failing/going out real fast.

I want to know what you think/ major diffrence/prefrence?

Here are the specs for my amp:

Mono subwoofer car amplifier

400 watts RMS x 1 at 4 ohms (600 watts RMS x 1 at 2 ohms)

Variable low-pass filter (50-200 Hz, 24 dB/octave)

Tuned Bass EQ (0-12 dB bass boost at 50 Hz)

Subsonic filter (24 dB at 15 Hz)

MOSFET power supply

STAR Topology (minimizes internal noise and prevents ground interference)

Speaker- and preamp-level inputs

Gold-plated screw terminals

Fuse rating: 30A x 2

4-gauge power and ground leads recommended wiring and hardware not included with Amplifier

Dimension: 13"W x 2-3/8"H x 9-1/2"D

Click to read more...

 

[Prowler573 5,000+ posts]

I have a Alpine M650 Amp I want to buy an Alpine Type R 12" Subwoofer. I want to know 2 OHM VS 4 OHM.
I have had a bad experience w/ 2 OHM in the past w/ them not working/failing/going out real fast.

I want to know what you think/ major diffrence/prefrence?

Here are the specs for my amp:

Mono subwoofer car amplifier

400 watts RMS x 1 at 4 ohms (600 watts RMS x 1 at 2 ohms)

Variable low-pass filter (50-200 Hz, 24 dB/octave)

Tuned Bass EQ (0-12 dB bass boost at 50 Hz)

Subsonic filter (24 dB at 15 Hz)

MOSFET power supply

STAR Topology (minimizes internal noise and prevents ground interference)

Speaker- and preamp-level inputs

Gold-plated screw terminals

Fuse rating: 30A x 2

4-gauge power and ground leads recommended wiring and hardware not included with Amplifier

Dimension: 13"W x 2-3/8"H x 9-1/2"D

Could you elaborate a bit more on what happened in the past regarding your bad experience running something at 2 Ohms?

The Type R is a dual voice coil driver. If you get the Dual 2 Ohm model then your wiring options are wiring the coils in parallel for a 1 Ohm load (which that amp isn't designed to run at safely if I recall correctly) or in series for a 4 Ohm load.

If you get the Dual 4 Ohm version then in parallel you'll have a 2 Ohm load (where your amp makes the most power) or in series you'll have an 8 Ohm load (which will cause your amp to output around 200 watts which will not do a Type R any justice at all)

 

[shaneyoung82 10+ year member]

A while back I had MTX blue thunder (1999) and I would get the 2 ohm. I replace the 2 ohm twice and each time they would work for about a day then blow or go out. Finally I replaced it with the 4ohm and never had another problem.

 

[Prowler573 5,000+ posts]

A while back I had MTX blue thunder (1999) and I would get the 2 ohm. I replace the 2 ohm twice and each time they would work for about a day then blow or go out. Finally I replaced it with the 4ohm and never had another problem.

Single coil 2 Ohm or dual coil? And what kind of sub are we talking about here? The problem you describe leads me to think of user error rather than driver failure but without more specific info I'm at a bit of a loss trying to troubleshoot here //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif Additionally which MTX amp, specifically? (meaning model # if you remember) If it was a multichannel unit running bridged showing it a 2 Ohm load could present problems (although it would usually create issues for the amp rather than the sub...) but if it was a monoblock a 2 Ohm load shouldn't have been problematic unless there was user error in the settings somewhere.

I've never had a problem running speakers or subs @ 2 Ohms unless the load I was showing the amp was lower than it was designed to operate at safely...

 

[shaneyoung82 10+ year member]

http://www.mtx.com/caraudio/archive/blueExtreme.cfm

Here is some info on the Sub

And here is the Amp

http://www.mtx.com/caraudio/archive/pro75x2.cfm

I bought those at circuit city and they were installed by them. There could have still been an error made by them.

 

[Prowler573 5,000+ posts]

It doesn't state specifically whether that is a Dual VC driver or not but I would guess just from reading that it isn't a DVC driver.

It also does not list that a 2 Ohm option was available for that model sub?

I'm a bit lost here...

I guess to address your original question with your current amp and the desire to drive a Type R with it if it were me I would do this:

Buy the Dual 4 Ohm version of the Type R and then wire the coils in parallel to achieve a nominal 2 Ohm load like so ~

That load is safe for your amp and will allow you to get the biggest power your amp is capable of making (while still being within the safe power limits for that particular sub)

After that call it a day and Bump Away!! //content.invisioncic.com/y282845/emoticons/thumbsup.gif.3287b36ca96645a13a43aff531f37f02.gif

 

[shaneyoung82 10+ year member]

Thanks, I was origionally looking at the 4 ohm. I'm sorry I couldn't find the info you wanted about the mtx products. But I appreciate your input, and I believe I will take you up on your advise.

 

[Prowler573 5,000+ posts]

You can run the Dual 2 Ohm version and wire the coils in series to a 4 Ohm load like so:

and that will give the sub the 400w @ 4 Ohms that your amp is rated for.

I think it is rated for 650w @ 2 Ohms? Am I remembering that correctly? (Please let me know if that is incorrect as Alpine isn't within my realm of 'I know those stats off the top of my head without question')

If I am remembering that right 650w isn't too much for a Type R and will better allow you to get more of the performance that sub is capable of.

400w will get it moving, don't get me wrong, but I really think it would like 650 better. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[shaneyoung82 10+ year member]

Here are specs for 2 and 4 ohm:

2OHM:

Specifications:

Peak Power Handling: 1500W

RMS Power Handling: 500W

Nominal Impedance: 2 ohm + 2 ohm

Frequency Response: 23-500Hz

Sensitivity (SPL@1W/1m): 85dB

Mounting Depth: 7.7"

Mounting Diameter - Front Mount: 10.9"

4OHM:

Features:

Peak Power Handling 1500 Watt

Nominal Power Handling 500 Watt

Frequency Respond 24 Hz - 500 Hz

Sensitivity 87 dB

Impedance 4 ohm

Specifications

High Excursion Tapered Half-Roll Surround

Aluminum Coated Dust Cap

Mirrored Progressive with Perimeter Venting

Frequency Response: 26Hz – 1kHz

Dual Voice Coil Design

Extra Rigid Steel Frame

Heavy-Duty 8GA Push Terminals

 

[Prowler573 5,000+ posts]

I think what you're missing here is the fact that the Type R is a dual voice coil driver ~ meaning that there are two voice coils rather than a single one.

Outside of that the Dual 4 Ohm and the Dual 2 Ohm are essentially the same driver but each has its own inherent wiring capabilities and it is up to the end user to decide which is more appropriate for their specific usage.

The "2 Ohm" version cannot be wired to a 2 Ohm load by itself and the "4 Ohm" version cannot be wired to a 4 Ohm load by itself.

Having said that you have to wire the coils either in series or in parallel depending on your needs. For your application using that particular Alpine amp the Dual 4 Ohm version (in my opinion) is more appropriate for you. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[shaneyoung82 10+ year member]

I see that there is 4 connections on the sub. Which leads me to believe this is where the term dual comes grom. I have never used this type before but I uderstand through looking at the schematic how you can use series or paralell. With that said I understand why the 4ohm would be a better choice for my application. Also, the MTX sub mentioned earlier was not a Dual component.

 

[Prowler573 5,000+ posts]

I see that there is 4 connections on the sub. Which leads me to believe this is where the term dual comes from.

Correct. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Some drivers have a single voice coil. Others have two voice coils (these would be the ones termed "Dual Voice Coil") Others (though not nearly as common) have four voice coils.

I have never used this type before but I uderstand through looking at the schematic how you can use series or parallel.

It's really no more difficult than using a single voice coil driver after you work out that there are certain ways it can be wired and how to implement those particulars with your intended application.Here's an unendingly handy link that I keep saved in my favorites. Very, very useful guide in my humble opinion.

Good luck with your setup! //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[BigProof 10+ year member]

sounds to me like you blew your mtx's by sending them too much power