OK, need some quick help with Ohms and speakers please!

[MoJoKe]

My Markbass rig is a CMD151p, with a little mark head producing 300w into 8 ohms and 500w into 4 ohms, so I'm guessing the 15" combo speaker is 8ohms. I also have an 8ohm 104HR cab, so with both together takes Ohms to 4, so gives 500w....?

Right, I have borrowed a Little giant 1000, which apparently provides 500w into 2 x 4ohm outputs...

How do I wire my speakers so that I get a good sound and don't risk damaging either amp or speakers?

Need to know before tonight!!

[Bill Fitzmaurice]

If you'd read this you'd have known last night:
http://basschat.co.uk/topic/135-impedance-etc/

[Protium]

From Ashdown:

[i]1000 WATT - The two SPEAKER OUTPUTS on [/i][i]the 1000 Watt model are driven [/i][i]independently by 2 x 500 watt output stages.[/i]
[i]Each socket can run into a 4 Ohm load for [/i][i]maximum output power.[/i]

So you can plug both cabs into one socket, or one cab into each socket. It will work either way - see which one sounds better (though the difference should be negligible)




[quote name='Bill Fitzmaurice' timestamp='1345991843' post='1783860']
If you'd read this you'd have known last night:
[url="http://basschat.co.uk/topic/135-impedance-etc/"]http://basschat.co.u...-impedance-etc/[/url]
[/quote]
Very helpful as usual

[pete.young]

Plug the markbass speaker into the extension socket. Leave the Ashdown in the car.

[xgsjx]

[quote name='pete.young' timestamp='1346085071' post='1785049']
Plug the markbass speaker into the extension socket. Leave the Ashdown in the car.
[/quote]

The head in the combo is on the blink.

[Wooks79]

[quote name='Bill Fitzmaurice' timestamp='1345991843' post='1783860']
If you'd read this you'd have known last night:
http://basschat.co.uk/topic/135-impedance-etc/
[/quote]

Now, i know things can get misconstrued on the internet, but... I don't think I've ever seen a single post where you don't come across as a grumpy unhelpful 'person'. So glad you choose to frequent forums to help spread your wisdom...

[Big_Stu]

[MoJoKe]

OK, so I tried what Protium suggested,

1. The 151 into one channel and 104 into the other - result; the amp sounding incredibly strained, my poor MB speaker cones moving about 6" in and out, trying to detach themselves from their chassis, even at relatively low volume.
2. The 151 cab into the "out" of 104 then into a single channel on the Ashdown - Result, quiet, poor tone, had to crank the Ashdown up high to get it to move some air, resulting in painful farty sounds, not harmonic bass loveliness

The moral of the tale, I didn't end up using the amp as it was borrowed, and I didn't want to damage it, or my precious MB speakers.... At this point i must say that I have never been an Ashdown lover, and this has sadly reinforced the fact.

In the end I was lent a PJB Suitcase and expansion cab by my lifesaving nephew. Lovely tight top end and middle, but those poor 8 x 5" speakers just couldn't come close to my MB at managing the bottom end of my Lakland 55-02's, but a great sound nonetheless, and in this case beggers really can only be eternally grateful!!

Thanks for all your help guys!!!

[JTUK]

Some people get a sound from Ashdown.....by and large, I think it is poor stuff...or more politely, not for me.
Even the 810 fridge didn't really cut it..

Your combo should sound good through the 410 and/or the 115... but not the 115 on its own.. unless it has a tweeter. Even then, I still think the amp works as though the pipes need unblocking.... and the LM11
doesn't really have the oomph at 8ohms and at volume.. Why the Ashdown can't run this, I don't get... I would expect the Eq to be lacking but not the power. Are you sure the Ashdown works ok..???

For a punchy loudish gig..I would think you MB combo would do much better paired with the 410.
I have heard so many single cab MB rigs and none of them really do it, to my ears.
I used to wonder why my mate runs MB amps with Epi's..now I know.

Just saying...

I'd certainly get it repaired and fired up into 2 cabs tho.. for those bigger gigs.

[Musky]

The Little Giants had a bit of a problem with the volume for the rated output of them. It was down to the output of the preamp apparently, which was on the low side. Putting a pedal to boost the volume between the pre and power amps is supposed to improve things no end.

[MoJoKe]

I just want to get my original setup working again, which is CMD151p combo (which has 1 x 15" and a tweeter and on its own is fine for rehearsals and small gigs), and a STD104HR (4 x 10). This has the advantage that it can be configured in three different ways, 1. as a 15 inch (+tweeter!) combo, 2. as a full rig for bigger gigs with 1 x 15 [i]and [/i]the 4 x 10 , or 3. the 15" speaker in the combo can be turned off and the head can be used just with the 4 x 10... It is so flexible. However, just been told the head will cost a bit over £100 to repair as the power supply is buggered, and i am currently penniless.....
Thankfully my immediate problem has gone away, as a friend has lent me a power amp, so I can use my GT6b as a preamp, and it powers my MB cabs reasonably well... not ideal, but it'll get me through....

Edited August 29, 2012 by MoJoKe

[MoJoKe]

[quote name='JTUK' timestamp='1346269952' post='1787347']
Are you sure the Ashdown works ok..???
[/quote]

Truthfully, no, I suspect not, and it was a loan from a local music shop, so didn't want to be the one who discovered it was faulty, in case he asked me to pay for the damage... my problems are bad enough as they are at the moment! though best to just not risk it... quite apart from the risk of blowing my cabs to bits!!!

Edit: sorry, that sounds really ungrateful and I really didn't mean it to sound like that.... the guy was genuinely trying to help me out of a spot, and for that I am really very grateful.... I have promised to buy strings from him from now on.... He's gonna get Elixirs in specially for me!

Edited August 29, 2012 by MoJoKe