Another Cab Query

[gilmour]

Thanks to all the responses to my previous posts.

I'm now the proud owner of an Eden Time Traveller WT405 and I love it, really accuratley reproduces the sound of the bass with too much additional tonal colouring (if that makes sense) it also has massivley powerfull EQ to boot (in case I decide to join a dub band), although I just leave it falt and it sounds lurvley.

For those of you that have seen my previous posts I've been having a bit of a dilemma with CABS. I can't afford to buy new ones. I currently Have a Trace Elliot 4 x 10 which i'm gonna get rid of (i reckon about £100 if anyones interested) and a Peavey 1x15. My plan was to keep the Peavey and stick a 2x10 with a tweeter on top of it, I liked the sound of the 4x10 with the 1x15 but that was overkill for the gigs I'm playing.

However I've just found out from the factory that my Peavey is the 4 ohm version. Does this mean that I can't put a 2x10 on top (even an 8 ohm one) as it might damage something? I'm quite keen to do this for a more even frequency response.

The amp power handling (according to the book) is : 8/4/2 ohms @ 250/405/620w

For years I used the 4x10 and 1x15 with my Trace Elliot head and nothing blew up, that said it was so loud I rarely had the volume turned up above 3!

Failing this I guess I'll have to start saving for a nice 2x10 and 1x15 at 8ohms.

Thanks again

[bass_ferret]

Having an 8 ohm and 4 ohm cab connected in parallel (assuming the speaker outs are parallel - some of the eden stuff is series but then you can always daisy chain the cabs) will give you an overall impedence of 3 ohms so you should be OK. However, the 1x15 4 ohm cab will still get twice the beans of the 8 ohm cab and if the Peavey is a Black Widow these have quite high sensitivity as well. What this means is that you might hardly hear an 8ohm 2x10.

A 4ohm Peavey 2x10 would seem to be the answer. They do come up quite often and are cheap as chips.

[Alien]

It looks like your amp is rated down to 2 Ohms, so adding another cab will be fine.

If you add another 4 Ohm cab, the overall impedance will drop to 2 Ohms, and your amp will deliver its full 620 Watts, which will be shared equally between the cabs. You'll want to look for a cab with a power rating of around 300-400 Watts.

If you add an 8 Ohm cab, your overall impedance will drop to around 2.7 Ohms, and your amp will deliver about 500-550 watts. However, only 1/3rd of this will go to the 8 Ohm cab, with the 4 Ohm taking the other 2/3rds. In this case, your cab would only need to be rated around 160-200 Watts.

I'm not even going to get into relative efficiencies, as it all starts getting pretty complicated.

Generally speaking, more cone area = more noise.

Andy

[gilmour]

Hmm Thanks for your responses,

My understanding is that I can add another 2x10 but that it should be rated at 4 ohms as I won;t hear an 8ohm one.

I'm a little worried about this as the back of the amp seems to have only 1 output for 2 ohms

it looks like this...

am I right in thinking the Speakon output is for 2 ohms? As Eden have no distributor in the uk they have been really really poor at responding to any queries (ie no response) shame 'cause it's a great product.

I'm not worried about voulme it's plenty loud enough, it's more about response, I love the sound of the Peavey 15, but it lacks a little punch that I think I'll get rom 10's - hence wanting a 2x10

Edited November 13, 2007 by gilmour

[Bill Fitzmaurice]

[quote name='gilmour' post='87891' date='Nov 13 2007, 09:52 AM']
am I right in thinking the Speakon output is for 2 ohms?[/quote]
When a SS amp output is impedance labeled that usually refers to the minimum total load that may be used. As a method of last resort you could consult the manual.

[Machines]

I think you'll be ok - the head handles a minimum of 2ohms and plugging both cabs in will give you ~3ohms.

The bit telling you its 406watts @ 4 ohms is just information.

[warwickhunt]

Your amp will operate at 2 ohms which effectively means that you can pretty much daisy-chain any 2 cabs to your amp as even the lowest impedence cabs will be 4ohms each giving your 2 ohms. Any combination of other ratings will be higher than that so no issue. A mismatch of 4 & 8 ohm cabs may well result in one cab getting more power than another but I 'personally' wouldn't worry massively about that as the science of it has so many permeatations (thermal ratings, porting, sensitivity etc etc) and caveats that it'd be easier to just plug it in, go carefully and listen to your speakers.

As for what plugs into where it would appear that with Speakon output is your 2 ohm jobbie; so you need to go from that output into one cab and from that cab into your second cab.

[bass_ferret]

Not the clearest labelling but I am guessing it means:
- use the speakon and daisychain = min 2 ohms.
- use the jacks = min 4 ohm each jack.
What happens if you plug 1 4ohm cab to speakon and 1 to jack I have know idea

Like Bill says you could RTFM - assuming it makes any more sense or indeed if you have one.

[gilmour]

thanks for all your responses guys.

The amp came with the wrong manual ! although I've now got a copy of the proper one and read it cover to cover, it didn't make things any clearer, I think I may re-read it though with all of these answers in mind and see if that helps.

Like I say it's not a volume issue merely about having a range of speaker combinations. I think for the time being I'll stick with the 1x15 at 4ohm. Just to be on the safe side. Whenever Im depping at bigger gigs they always provide a backline anyway (although it's usually an Amped SVT, not really my taste)!

Thanks

[jacko]

According to the online manual, the outputs are wired in parallel. This means that you could theoretically use 3 cabinets as long as one of them has a speakon cable AND the total load isn't less than 2 OHMs. However, they also go on to say this...

"We have designed our amplifiers to operate safely at 2 Ohms only because
everyone else is doing it and some users expect it. However, we much prefer
operating at 8 or 4 Ohms because of the markedly improved quality of tone
and dynamic response. But if you really want to, you can operate your Time
Traveler at 2 Ohms without worry."

If you're only using one cabinet and its 2ohms then use the speakon as they were designed to make the voltages involved safer. (less risk of electrical shock).