Running Little Mark II into wrong (impedance) cabs in series

[mintybassman]

Hey Bassing Comrades,

My trusty workhorse head got nicked at a gig [color="#0000FF"]([url="http://www.peavey.com/media/pdf/manuals/80301702.pdf"]Peavey Mark VII XP Bass Head[/url][/color])

So i got the [color="#0000FF"][url="http://www.markbass.it/products.php?lingua=en&cat=1&vedi=69"]Mark Bass Little Mark II[/url][/color] paying no consideration to impedance, doh!

I have these two cabs, workhorses once again:

[color="#0000FF"][url="http://www.peavey.com/media/pdf/manuals/80300395.pdf"]BX115 BW[/url]
[url="http://www.peavey.com/media/pdf/manuals/80301560.pdf"]TX210[/url][/color]

So when I first got them i hooked them up in parallel to hear the awesome 500W and my amp kept safety switching itself off , after realising my mistake, i've been running one cable from the back of my amp and into splitter taking the signal to both cabs in series basically. This is fine, "sound comes out n everyfin'" but to my understanding i'm not making the most of my head and am running at less than i had before which just isn't enough for me .

So basically, with spending as little money as possible what can i do to take advantage of the 500W i.e. change impedance of cabs? replace speakers? sod it all and save for new cabs etc? i'd like to explore the impedance thing first.

[i]Also got a bass for sale Stingray V, Metallic Blue Dawn rock bottom lowered to 800quids! [color="#0000FF"][url="http://basschat.co.uk/index.php?showtopic=18644&st=0&p=190121&#entry190121"]Stingray V[/url][/color] Let me know.[/i]

[DirkThrust]

Unfortunately your options are fairly limited. You can't rewire your cabs to alter the impedance and changing the drivers is not really cost effective. You'd probably spend more on drivers than the cabs are worth.

In your position I'd save the money and put it towards some new cabs. I owned the same pair of cabs and while they are good sounding cabs, these days there are much lighter and better sounding alternatives around. Have a look in the classifieds on here.

[stevie]

[quote name='mintybassman' post='194355' date='May 8 2008, 01:29 AM']Hey Bassing Comrades,

My trusty workhorse head got nicked at a gig [color="#0000FF"]([url="http://www.peavey.com/media/pdf/manuals/80301702.pdf"]Peavey Mark VII XP Bass Head[/url][/color])

So i got the [color="#0000FF"][url="http://www.markbass.it/products.php?lingua=en&cat=1&vedi=69"]Mark Bass Little Mark II[/url][/color] paying no consideration to impedance, doh!

I have these two cabs, workhorses once again:

[color="#0000FF"][url="http://www.peavey.com/media/pdf/manuals/80300395.pdf"]BX115 BW[/url]
[url="http://www.peavey.com/media/pdf/manuals/80301560.pdf"]TX210[/url][/color][/quote]

What's the impedance of the 15?

[mintybassman]

[quote name='stevie' post='194451' date='May 8 2008, 09:27 AM']What's the impedance of the 15?[/quote]

4 ohms.

Think this calculation explains it:

Both cabs are 4 Ohms each.

so in parallel it'd be 1/((1/4) + (1/4)) = 2 Ohms (eeep!)

In series it'd be 4 + 4 = 8 ohms (limiting the power of the amp!)

[bass_ferret]

Either: Just use one of the cabs? Whichever one sound best. Cost is zero.

Or: Sell the cabs and buy 2x8 ohm cabs or one 4 ohm cab. Cost is lots.

[pete.young]

[quote name='bass_ferret' post='194615' date='May 8 2008, 12:51 PM']Either: Just use one of the cabs? Whichever one sound best. Cost is zero.

Or: Sell the cabs and buy 2x8 ohm cabs or one 4 ohm cab. Cost is lots.[/quote]
Or, sell the LM2 and buy something that will run down to 2 Ohms. Even in the current climate it shouldn't be hard to shift an LM2.

[phsycoandy]

You could just buy my Epifani UL310 it sounds huge with my LM11 and u get to use the full 500 watts if u dare!

Edited May 8, 2008 by phsycoandy

[bass_ferret]

[quote name='bass_ferret' post='194615' date='May 8 2008, 12:51 PM']Either: Just use one of the cabs? Whichever one sound best. Cost is zero.

Or: Sell the cabs and buy 2x8 ohm cabs or one 4 ohm cab. Cost is lots.[/quote]


[quote name='pete.young' post='194794' date='May 8 2008, 04:32 PM']Or, sell the LM2 and buy something that will run down to 2 Ohms. Even in the current climate it shouldn't be hard to shift an LM2.[/quote]
My bad. I should not have assumed he would want to keep the shiny new amp and ditch the old Peavey cabs

[Bill Fitzmaurice]

A first order crossover at 150 Hz would route the lows to the 15, the highs to the 2x10, and keep the overall load at 4 ohms. Get component values at [url="http://www.lalena.com/Audio/FAQ/XOver/"]http://www.lalena.com/Audio/FAQ/XOver/[/url]

[mintybassman]

Ah cross-over. Now we're talking...

Would changing my EQ on my amp effect this? i.e. push the signals too high etc?

Am i buying one or making one? Or am i naive to the humungous complexity of that task?

What kind fo prices am i looking at for one?

This is new territory for me.

[stevie]

[quote name='Bill Fitzmaurice' post='194969' date='May 8 2008, 08:30 PM']A first order crossover at 150 Hz would route the lows to the 15, the highs to the 2x10, and keep the overall load at 4 ohms. Get component values at [url="http://www.lalena.com/Audio/FAQ/XOver/"]http://www.lalena.com/Audio/FAQ/XOver/[/url][/quote]

Wouldn't you be concerned about mis-termination? As system output would still be limited by the excursion of the bass driver, what exactly would be the advantage over just using the 15?

[Bill Fitzmaurice]

[quote name='mintybassman' post='194978' date='May 8 2008, 02:43 PM']Ah cross-over. Now we're talking...

Would changing my EQ on my amp effect this? i.e. push the signals too high etc?

Am i buying one or making one? Or am i naive to the humungous complexity of that task?

What kind fo prices am i looking at for one?

This is new territory for me.[/quote]
Making is your best option. It's a simple circuit, only two parts, put them in a box with an input jack to go to the amp, outputs to each cab. Figure $50, a lot cheaper than new cabs. Finding the parts on your side of the pond is the most difficult part, very odd since the #1 source, Jantzen, is Danish.

[alexclaber]

[quote name='Bill Fitzmaurice' post='195162' date='May 9 2008, 01:26 AM']Finding the parts on your side of the pond is the most difficult part, very odd since the #1 source, Jantzen, is Danish.[/quote]

I'd recommend this place:

[url="http://www.audio-components.co.uk/"]http://www.audio-components.co.uk/[/url]

Alex

[andy67]

go to sound control and haggle over the full range ampeg b410hlf cab its awsome!

then sell your peavey cabs.

adny

[bass_ferret]

I wont tell you what to buy because you may have different taste to me. I would be inclined to avoid MarkBass cabs because they dont seem to match the standards of the amps.

[stevie]

Minty, the limiting factor in your current system is not necessarily your amp. It's probably the 2 x 10. The cheapest way of sorting your system out would be to find someone willing to swap your 4 ohm 2 x 10 for an 8 ohm version. That shouldn't actually cost anything and it will re-balance your system.

If you think that's an option, I'd be glad to explain why it should work.

[bass_ferret]

[quote name='stevie' post='195572' date='May 9 2008, 05:15 PM']Minty, the limiting factor in your current system is not necessarily your amp. It's probably the 2 x 10. The cheapest way of sorting your system out would be to find someone willing to swap your 4 ohm 2 x 10 for an 8 ohm version. That shouldn't actually cost anything and it will re-balance your system.

If you think that's an option, I'd be glad to explain why it should work.[/quote]
How is having an 8 ohm 2x10 with a 4 ohm 1x15 going to help?

[stevie]

[quote name='bass_ferret' post='195594' date='May 9 2008, 05:43 PM']How is having an 8 ohm 2x10 with a 4 ohm 1x15 going to help?[/quote]

Upon reflection, perhaps not. I was assuming that the Mark Bass would be comfortable with a load of 3.5 ohms or so, which a lot of power amps are. This might be sailing a bit close to the wind. If it were my amp I'd probably not want to risk it though.

[Bassinat66]

[quote name='mintybassman' post='194551' date='May 8 2008, 01:00 AM']4 ohms.

Think this calculation explains it:

Both cabs are 4 Ohms each.

so in parallel it'd be 1/((1/4) + (1/4)) = 2 Ohms (eeep!)

In series it'd be 4 + 4 = 8 ohms (limiting the power of the amp!)[/quote]

Bassinat66

I've been looking into this cuz im buying a mark bass little mark 2. This from mark bass web site:
You can use two 8 ohm cabinets with any Markbass head. The total ohm load then becomes 4 ohms, which means that you get more power from the amp. But be warned, you can’t use Markbass amps into an ohm load lower than 4. That means you cannot use two 4 ohm cabinets, or one 4 ohm and one 8 ohm! There are two speaker outputs on every Markbass head. Simply connect one output to each cabinet. Be warned that using your amp into an ohm load lower than 4 ohms will damage your amp and will not be covered under warranty!

[Bassinat66]

Hey, looks like you got answer!

I'll put in my 2 bass cents:

Bassinat66

I've been looking into this cuz im buying a mark bass little mark 2. This from mark bass web site:
You can use two 8 ohm cabinets with any Markbass head. The total ohm load then becomes 4 ohms, which means that you get more power from the amp. But be warned, you can’t use Markbass amps into an ohm load lower than 4. That means you cannot use two 4 ohm cabinets, or one 4 ohm and one 8 ohm! There are two speaker outputs on every Markbass head. Simply connect one output to each cabinet. Be warned that using your amp into an ohm load lower than 4 ohms will damage your amp and will not be covered under warranty!