SPEAKERS & OHMS!!!! Everything you need to know about SPEAKERS & OHMS!!! - Page 4

scxtt · #46 03.31.05, 9:51 PM

Quote:

fburn666 --
well i was told before at guitarcenter that i should put it on 8ohms but that was with two 4x12s one 16ohm cab and one 8ohm cab

yes, well they're dumbasses ...

...

(1/a + 1/b) = 1/c

a = cab #1
b = cab #2
c = load created ...

(1/8 + 1/16) = 1/5.33

Deke · #47 03.31.05, 10:39 PM

is there danger in putting a triple rectifier with a standard mesa/boogie rectifier cabinet? those things are rated at 140 watts. will it eventually burn or will it be ok if i don't blast the thing to 10 but instead maybe at a safe voluem set at 5-6?

scxtt · #48 03.31.05, 11:09 PM

Quote:

Deke --
is there danger . . . etc, etc, etc ...

no offense, but how many times do you need to ask this?

http://guitargeek.com/chat/showthrea...threadid=52199

sick on you · #49 04.05.05, 11:48 AM

i dont know if this has been discussed in here, but can somebody tell me what this means?

http://www.choadin.com/uploader/user...ou/peavey2.jpg

does my amp run at 4ohms? 8? does it vary? i thought it was 4.

i have a couple of questions. i have 2 amps that im messing with. i have a peavey vintage 2x12 combo and i have a fender prosonic. the fender can operate at 4,8, or 16 ohms, and the cabinet (tonemaster)'s impedence is 16ohms. i know i can run 16 to 16, but running it 8 to 16 (head to cabinet) makes the speakers break up much better. am i going to run into any problems running them on different impedences? and could i run a 4 ohm head into a 16 ohm cab?

my other question is for the amp whos specs are posted above. it is a peavey vintage 2x12 combo. i want to run it through a cabinet cause the amp sounds killer when you can keep it at low volumes. what i gather from the specs above is that its impedence is 4ohms. so i shouldnt have any trouble running it through a vox cab also rated at 4ohms, right? my main concern is that i know what the impedence of that peavey is, cause it doesnt say anywhere, and that 8 4 2 thing above is kinda confusing. i dont want to run it through a 4ohm cab if it is actually rated at 8ohms.

please help. im confused.

scxtt · #50 04.05.05, 7:42 PM

Quote:

sick on you --
i dont know if this has been discussed in here, but can somebody tell me what this means?

does my amp run at 4ohms? 8? does it vary? i thought it was 4.

well, it seems that the amp expect a 4ohm load: 110W @ 4ohms ... the info below that is just telling you some extraneous info ... you can tell for sure by measuring the load the 2x12 creates ...

Quote:

i have a peavey vintage 2x12 combo and i have a fender prosonic.

is that a prosonic head?

Quote:

. . . but running it 8 to 16 (head to cabinet) makes the speakers break up much better. am i going to run into any problems running them on different impedences? and could i run a 4 ohm head into a 16 ohm cab?

if you like how it sounds/feels, there's no real problem running that [8 --> 16] mismatch ... i WOULD NOT do the [4 --> 16] mismatch ... too much stress on the amp ...

Quote:

so i shouldnt have any trouble running it through a vox cab also rated at 4ohms, right?

you'll have to unplug the internal speakers unless there's a 2nd jack ... you need a TOTAL 4ohm load, not just another 4ohm cab ... the peavey would have to run @ 2ohms for you to use 2 4ohm cabs ...

Quote:

my main concern is that i know what the impedence of that peavey is, cause it doesnt say anywhere, and that 8 4 2 thing above is kinda confusing. i dont want to run it through a 4ohm cab if it is actually rated at 8ohms.

please help. im confused.

are the speakers labeled w/ their impedance rating? if so, you can look @ them and how their wired and figure out the impedance of the 2x12 ...

#51 04.05.05, 11:30 PM

ok guys just got this 1x15" cab done (sorry no pics but ill tell ya its ugly lol). Sounds ok puts alot more bass into my rig.
Funny part is the cab I used was an old 15" speaker sterio cab i just cut it in half lol. It works thats all I care about first cab i built next maybe a better looking 4x12 or guitar.

rexreason · #52 04.14.05, 10:58 PM

Can anyone help me figure out the impedence of my cabinet? It's a 4 x 12" Fender with 75 watt Celestions. The magnets on the speakers have 16 ohms printed on them, but I've been led to believe that's the the impedence of the cabinet overall. To the best of my knowledge it has not been wired any differently than the factory specs.

JJ321 · #53 05.03.05, 6:49 PM

I've been looking into building my own speaker cabinets lately and I just wanted to make sure that I understand this correctly. I plan on building two 2x12 cabinets. What I want to do is run the two 2x12 cabs on one side of a Mesa 50/50 (when I get it) and run my Marshall 1960A cabinet on the other side. After reading the first post, wiring them in parallel seems to be the way that I want to do it. So, with (2) 8 ohm speakers in each cabinet, the total load will be 8 ohms, right? Any help would be greatly appreciated.

zadiqof · #54 05.04.05, 11:51 AM

alright, so after reading this i think ive got my rig hooked up correctly.

*Matchless Chieftain head 3 outputs:
(4ohm/8ohm/16ohm)
*Marshall 1960ax with a 16 in.
*Orange 2x12 with a 16 in.

The 8 ohm output on the Matchless is plugged in to the Marshall.
The 16 ohm output on the Matchless is plugged in to the Orange.

Page_Master · #55 05.28.05, 3:06 AM

i have a 4x12 mono cab with Celestion G12M 70 rated at 16ohms. the bottom right speaker has blown and sound like ****. can't i just disconnect it from the circuit and turn into a 3x12 or a 2x12 cab?

Funkatron_Shaun · #56 05.30.05, 6:34 PM

I have a sovtek mig 50 and an avatar 2x12 with vintage 30s (8 ohm cab/ 120 watts) on the way. my question is this: could i hook the cab into the 4 ohm output and be ok?

moire · #57 06.14.05, 1:04 PM

From an early post in this thread:

Quote:

Originally posted by macmidi
It is worth pointing out that most players will only be concerned with the "parallel" impedance formula, which is what comes into effect when you simply connect multiple cabs to a typical amp's speaker jacks -- not counting Ampegs, Fenders, etc. with "EXTENSION SPEAKER" jacks, which treat a load differently.

Can anyone elaborate on the difference between internal connections and extension speaker jacks in Fender amps?

airfall · #58 06.21.05, 7:46 PM

Quote:

Originally posted by Elkvis
I don't know if any of you have ever looked at speaker impedance plots, but the rated impedance is usually only valid at 1khz.

actually the rated impedence ("nominal" impedence) is at 400Hz. it usually doesnt change much between 400 and 1000, but that's the convention. most speakers will have DC resistance about 75% their nominal value (3Ω, 6Ω, 12Ω).