parallel outputs & parallel cabs... wiring?

[OTTO]

correct?

i have 2 sunn 412sr column cabs & im just trying to make 10000% sure I'm hooking them up &
running them correctly.

soldano avenger (capable of 4,6,16ohms)
 
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2 SUNN 412 SR COLUMN CABS




THX FELLAS

[EdBass]

Patience is a virtue, this is a very low traffic forum.
Assuming the output jacks on the Soldano are wired in parallel, which they most likely are, plugging in two 8 ohm cabs would be showing the OT a 4 ohm load.
So... yes.

[OTTO]

thanks so much ed!

also.. the cabs have parallel input output jacks
not sure which way is appropriate:

1. chain them together? ie: out of ONE (not both) output on the amp into the top jack on cab -> out the lower one -> into the next cab?
OR
2. out left output into cab left. out right output into cab right.

will ohms be the same either way since their parallel?

i did a quick illustration of what the back of these look like



(a) i do not want to plug into the wrong jack on the cabs (if thats possible)
(b) I want to make sure that once wired correctly, the ohm calculations are correct.


thanks about a million and a half!

[EdBass]

I'd plug one into each jack on the amp and set it to 4 ohms. I personally only daisy chain when there is no other option. The word "chain" is appropriate here, as in the old saying "a chain is only as strong as it's weakest link".
Depending on how those cabs are wired internally, an open VC or two or a bad solder joint in one cab could leave you with a serious load problem on your amp's OT if they are "chained" using one output jack, and at big volume that could take out some expensive hardware fast; you could even see/smell the magic smoke before you even got done saying "WTF???" because your rig stopped making noise.
If you use both jacks the worst that could happen is you instantly double the impedance on the OT, not a good thing but not catastrophic. At least you have time to figure out what happened and switch the impedance selector to 8 to finish the set.

Also, I always put a meter on a cabinet before I use it the first time to be sure it's what impedance I think it is.

[OTTO]

again, thanks ed!

I dont have a meter. how do I go about getting one of these?

[EdBass]

I don't know where you are located, but if you are in North America you can get them really cheap from Harbor Freight;

http://www.harborfreight.com/catalogsearch/result?q=multimeter

If you are elsewhere I'm sure there are similar outlets to buy them.

I use one regularly and it's often thrown into a gig bag, dropped, knocked off speaker columns, etc. and the lower priced ones won't hold up too well; generally when I need one I NEED one. So, I stepped up and bought a Fluke several years ago.
Kind of overkill for casual use though, one of the <$20 meters should give you good service if you are careful with it.

[CLD]

Grainger has a good selection of meters, too.

[Rex B]

Many cheap meters won't have a resistance setting low enough to distinguish between 4 and 16 ohms. My cheap meter's resistance setting is 1000 ohms at full meter swing. Worthless for measuring speaker impedance.You will need a meter with a "low Z" or low impedance measuring function. Also, as mentioned many times in this forum, a "nominal" 4 ohm speaker will measure about 2.8 to 3.2 ohms, 8 ohm speaker will be about 5.6 to 6.4 ohms, and a 16 ohm speaker will be about 11 to 13 ohms. This is because the meter reads at 0hz or DC, and the speaker impedance rating is something of an "average" reading over the speakers operating frequency range.

[max2343]

I just picked up the same cabs and hooked them up to my meter to check-em. Both came in at 7.6 ohms and my Amp head has hook up for 4 16ohm cabs so I plugged both into the head with its own cable but with these cabs I had to  repair each and every speaker cable connection because they fall off when you blast-em. Mine blow a fuse after about a half an hour and I rechecked each cab and found one at _0_. So I'd replace each and every speaker connector if I were you and make sure each is a tight fit. Those do sound Great don't they. Mine break up real nice. These cabs are early 70's? aren't they? I think my numbers on the speakers come back to that.

[Isaac]

Yes, early to mid seventies.