Speaker Wiring - Need to get 8ohms!

[Raslee]

Ok here goes,

I have two Ashdown Mag cabs a 15" & 4x10", both 8ohms. I have an Eden WT800A with a bridged output running 800Watts at 8ohms. Now i know when i link the two Ashdown cabs together i get 4ohms but i need to somehow get 8ohms . Now i want to use both cabs as i need at least 500W with head room on stage (yes i know its bloody loud but i'm playing with some reggae guys where bass is everything + they/we have a monster soundsystem which the drummer puts his Roland TD20 through...and is quite possibly the loudest electronic drummer i've ever played with-turning down is not an option!).

So can i get 8ohms doing some weird and wonderful wiring, if so how? Could i add another cab, say a 2x10 and magic a total impedance of 8ohms from somewhere? I can even goto 6ohms if needs be coming in on the Eden but unfortunately not as low as 4ohms. Eden unfortunately no longer do the tech mod on these amps that they were offering many moons ago whcih converted the bridge out put from 8ohms @ 800W to 4ohms @ 1200....if anyone has info on this mod i'd like to hear.

Also if i put a multimeter, on resistance, across a speaker would it show the ohmage of that speaker i.e 8ohms or 4 ohms etc...actually i think that's a silly question as it impedance right?

Help the dyslexic electronics people here...even though ironically i studied electronics at 17 but slept most the time

Edited October 29, 2009 by Rasta

[obbm]

Firstly there is no way you can get 8-ohms from two 8-ohm cabs, it's against the Laws of Physics, however;

Your two cabs in parallel (daisy chained) together give you 4-ohms so you could put another 4-ohm cab in series (you need a special cable for this).

The down side is that the new 4-ohm cab will take 50% of the amps output.

Simplest solution is change cabs to something more appropriate or get a cheap power amp and use the Eden as a pre-amp.

Impedance is a measurement relative to frequency so you can't measure it with a multimeter, all you can check is dc resistance, although you will get a close indication. ie. a 4-ohm cab will measure closer to 4-ohms than an 8-ohm cab.

[Raslee]

[quote name='dave.c' post='639705' date='Oct 29 2009, 08:20 AM']I use a WT800A bridged into an 8 ohm Eden410XLT and a 16 ohm Eden210XLT (which i bought as a 4ohm cab and rewired) so in effect I have a 6x10 cab with all drivers getting an equal amount of juice, this works really well and I can just use the 410 if I need to. doesn't really help with your 1x15 though I suppose, but it is loud!

Dave[/quote]

Thankls for the replies guys...yeah i think ditch the 15" and get and 2x10 4ohm and wire to 16ohm...i guess that will give me 8ohms right?

'Your two cabs in parallel (daisy chained) together give you 4-ohms so you could put another 4-ohm cab in series (you need a special cable for this)'

Where would i get series cables?


Lx

[Protium]

Four Kappalite 3015s will do the trick

[Paul_C]

why not D.I. into the PA and use your rig as onstage monitoring ?

[Raslee]

[quote name='dave.c' post='640390' date='Oct 29 2009, 07:05 PM']Your 8ohm 4x10 and a 16ohm 2x10 will give you 5.3 ohms I think, the same as a 6x10 cab which seem to be nominally labelled at 6 ohms. according to Eden this is ok with a WT800A.[/quote]
Ah cool, i used to run a 6ohm Warwick 6x10 into the Eden and thats when it was at its best for headroom. right 2x10 hunt its...quite fancy an Eden actually.

[51m0n]

Just get 2 more of exactly the same cabs as you have now, then dont bridge the Eden, but run parallel from the bottom to the 2 1x15s and parallel to the top fro the 2 2x10s

You will get a MASSIVE increase in volume this way (~6dB).

OR better yet buy 2 Barefaced Vintages (4 Ohms each) and run the whole lot [b]not[/b] bridged.

That would tear the roof of the sucka all right since the vintage is more efficient

[alexclaber]

[quote name='51m0n' post='640776' date='Oct 30 2009, 09:32 AM']OR better yet buy 2 Barefaced Vintages (4 Ohms each) and run the whole lot [b]not[/b] bridged.[/quote]

Or two D.M.s in series, bridged. One scary 4x12" rig!

Alex

P.S. If you check resistance with a multimeter it'll come out as ~65% of the nominal impedance, so 5-6 ohms for an 8 ohm rig.

[51m0n]

Or (and I admit this is now getting properly silly)

A Big One and a Big Sub not bridged, since you are doing dub that would be all the deep bass you could ever ever need.

You may have to take out extra insurance to cover for the inadvertant bowel surgery that that would cause on the audience (and maybe yourself) though....

[Raslee]

[quote name='51m0n' post='640912' date='Oct 30 2009, 11:31 AM']inadvertant bowel surgery[/quote]
Now your talking my language, what set up is this then?

[Raslee]

What ohmage are the speakers in a Eden 210XLT 8ohm ?

[crez5150]

It always makes me smile when people say 'ohmage'.