2 ohm cab

[munkonthehill]

As the title suggests folks.

Just seeing if theres any cabs out there with 2ohm impedance??????????

If so, does anyone have one for sale???????

[xgsjx]

Very good Q. You could rewire a 4x10 to run at 2 ohms.

[Mr. Foxen]

Generally an 8 ohm 4 speaker cab can be rewired to 2 ohm, but not no-one makes them like that because it is more trouble than its worth, except possibly peavey, as I've seen photos of a 2 ohm 4x12, which matches Peavey's tendency to make amps happy to 2 ohm.

[markstuk]

May also be worth pointing out that when I was looking to replace the 8 Ohm driver in my Ashdown MAG300 all the 4 ohm versions of the drivers were 3 db less efficient than the 8 Ohm ones .. So I I fitted an 8 Ohm 3015 Kappalite for obvious reasons.. Also as everyone says make sure your amp is guaranteed stable into 2 ohms....

[Stylon Pilson]

OP has an Ampeg B5R which is rated down to 2 ohms, and presumably is trying to get the full 500W out of it, instead of the 350W that you get at 4 ohm.

To the OP - if you do succeed in this, then prepare for somewhat disappointing results.

S.P.

[Bill Fitzmaurice]

[quote name='Stylon Pilson' post='952090' date='Sep 10 2010, 12:57 PM']To the OP - if you do succeed in this, then prepare for somewhat disappointing results.

S.P.[/quote]He should be prepared for total disappointment. Watts and volume are not directly related.

[munkonthehill]

so what do I get in comparison of the 350watts and 500watts then?????

the answer of 150watts isnt acceptable

[Colledge]

well having 350w through more speakers, you will get more volume than 500w through one cab.... however if the songle cab is bigger / higher spl than what you are using at the moment, then it would be louder, but not much louder than if you were running 250 watts into it.

[munkonthehill]

[quote name='Colledge' post='952145' date='Sep 10 2010, 07:02 PM']well having 350w through more speakers, you will get more volume than 500w through one cab.... however if the songle cab is bigger / higher spl than what you are using at the moment, then it would be louder, but not much louder than if you were running 250 watts into it.[/quote]

yeah i dig where your coming from, thanks for the insight mate.

[xgsjx]

It isn't just about how many watts goes into a cab, it's about how much air is being moved. 500 watts moving 2 4x10 cabs is gonna move just short of twice as much air as 500 watts going into 1 4x10 thus being a whole load louder & retain the sound that you would expect to get from your existing rig.

The old "full output from the head into one cab will give you max volume" is a myth. If you put 2 8 ohm 4x10 cabs on your amp (getting about 300w out your head), it would more than likely be louder than the full whack into one 2 ohm 4x10 because you're moving a larger mass of air with the extra speakers. Hope this helps.

[munkonthehill]

[quote name='xgsjx' post='952237' date='Sep 10 2010, 08:42 PM']It isn't just about how many watts goes into a cab, it's about how much air is being moved. 500 watts moving 2 4x10 cabs is gonna move just short of twice as much air as 500 watts going into 1 4x10 thus being a whole load louder & retain the sound that you would expect to get from your existing rig.

The old "full output from the head into one cab will give you max volume" is a myth. If you put 2 8 ohm 4x10 cabs on your amp (getting about 300w out your head), it would more than likely be louder than the full whack into one 2 ohm 4x10 because you're moving a larger mass of air with the extra speakers. Hope this helps.[/quote]


it sure does buddy. Thanks for that.

[Bill Fitzmaurice]

[quote name='munkonthehill' post='952141' date='Sep 10 2010, 01:58 PM']so what do I get in comparison of the 350watts and 500watts then?????[/quote]
2dB. To sound twice as loud requires 10dB. That's the difference between 350w and 3500w.
And that 2dB is best case, assuming your speakers can make use of the additional power. Between thermal and mechanical power compression few speakers can actually make use of more than half their thermal wattage ratings, and most come in closer to 40%. So the answer might be no difference.

Edited September 10, 2010 by Bill Fitzmaurice

[charic]

[quote name='Bill Fitzmaurice' post='952296' date='Sep 10 2010, 10:22 PM']2dB. To sound twice as loud requires 10dB. That's the difference between 350w and 3500w.
And that 2dB is best case, assuming your speakers can make use of the additional power. Between thermal and mechanical power compression few speakers can actually make use of more than half their thermal wattage ratings, and most come in closer to 40%. So the answer might be no difference.[/quote]

I thought it was 6db. Pretty sure that's what we were told at Uni anyway.

[4-string-thing]

I did a gig recently using my Acoustic 220, which can run at 2 ohms. I used my Acoustic 2x15 4 ohm cab and added my Acoustic 1x15 which is also 4 ohms. I have to say adding the extra 15" cone and halving the impedance made my amp no louder whatsoever!

[munkonthehill]

[quote name='4-string-thing' post='952476' date='Sep 11 2010, 09:22 AM']I did a gig recently using my Acoustic 220, which can run at 2 ohms. I used my Acoustic 2x15 4 ohm cab and added my Acoustic 1x15 which is also 4 ohms. I have to say adding the extra 15" cone and halving the impedance made my amp no louder whatsoever![/quote]

yeah looks like its a wasted journey with this 2 ohm malarky.


Thanks everyone with your input. Its helped alot.

[Prime_BASS]

Buy another 4ohm cab.

[Mr. Foxen]

[quote name='4-string-thing' post='952476' date='Sep 11 2010, 09:22 AM']I did a gig recently using my Acoustic 220, which can run at 2 ohms. I used my Acoustic 2x15 4 ohm cab and added my Acoustic 1x15 which is also 4 ohms. I have to say adding the extra 15" cone and halving the impedance made my amp no louder whatsoever![/quote]

I think most of that would achieve is giving you the upper power limit of the 1x15 x2, so not much further ahead than the 2x15, except for 50% more speaker area.

[4-string-thing]

[quote name='Mr. Foxen' post='952640' date='Sep 11 2010, 12:23 PM']I think most of that would achieve is giving you the upper power limit of the 1x15 x2, so not much further ahead than the 2x15, except for 50% more speaker area.[/quote]

I think adding the extra cab added very little, if anything to be fair. The only advantage to my (admittedly poor) ears was maybe I could hear myself a bit better due to the 1x15 being at head height?

Oh, and it looks cool having a 6ft high stack!

[Alien]

[quote name='munkonthehill' post='952141' date='Sep 10 2010, 06:58 PM']so what do I get in comparison of the 350watts and 500watts then?????

the answer of 150watts isnt acceptable [/quote]

Take a look at [url="http://basschat.co.uk/index.php?s=&showtopic=101784&view=findpost&p=949034"]this post[/url] and have a listen to the WAV file there.

That's what a 26% increase in power sounds like.

A

[markstuk]

Can we start on XMAX and VD soon? :-)

[Bill Fitzmaurice]

[quote name='markstuk' post='952798' date='Sep 11 2010, 10:20 AM']Can we start on XMAX and VD soon? :-)[/quote]
VD is what you can catch if you're not careful about with whom you canoodle at the IMAX.