rukind.com

Grateful Dead Music Forum

A place to talk about the music of the Grateful Dead 

Chat about Equipment Info
 #101247  by inthedark
 Thu Jul 21, 2011 9:30 am
I have a Fender Hotrod Deville and I just bought 2 speakers to replace the stock ones.

But the the new speakers i got are 16ohm. and I believe the amp is 8ohm. Will i be ok using the 2 16ohm speakers ?
 #101253  by myoung6923
 Thu Jul 21, 2011 10:14 am
what are the stock speakers rated at? I know that twins are rated to put out 4 ohms so putting in 2 8 ohm is series will give you that. Typically it is not at all recommended to run it at a mismatch like that.
 #101255  by inthedark
 Thu Jul 21, 2011 10:35 am
myoung6923 wrote:what are the stock speakers rated at? I know that twins are rated to put out 4 ohms so putting in 2 8 ohm is series will give you that. Typically it is not at all recommended to run it at a mismatch like that.

I was wrong the amp puts out 4ohm. So the stock speakers are 8 ohms. So i guess i need to get that Weber Z thang so i can match

Grr...

-Walt
 #101262  by FretfulDave
 Thu Jul 21, 2011 1:06 pm
myoung6923 wrote:what are the stock speakers rated at? I know that twins are rated to put out 4 ohms so putting in 2 8 ohm is series will give you that. Typically it is not at all recommended to run it at a mismatch like that.
just to be sure, I think you mean two 8 ohm speakers in parallel will provide a 4 ohm load. two 16 ohm speakers in parallel will provide an 8 ohm load.

for series, you add the ohms, i.e. 2 8 ohm speakers in series = 16 ohm load.

An ohm mismatch for tube amps in particular is not a good thing for sure.

Please correct me if I am mistaken.


Dave
 #101264  by JonnyBoy
 Thu Jul 21, 2011 1:19 pm
I think at 8 ohms with a twin you are OK, you can run another 8 ohm speaker in a separate cab and get the 4 ohms... The higher ohms will give you less volume though... I think it is OK to go from 2-8 ohms with a tube amp with its optimal operating range being 4 ohms. I know with my gear I would follow manufacturers spec so it will last... I think Jim Shank use to run his twin with a higher ohm rating sometimes and only mentioned the drop in volume, so instead of being on 3 you will be on 5. I think you really don't want to go lower than 4 but higher is not an issue. I could be wrong, so double check it.
 #101284  by inthedark
 Thu Jul 21, 2011 6:12 pm
JonnyBoy wrote:I think at 8 ohms with a twin you are OK, you can run another 8 ohm speaker in a separate cab and get the 4 ohms... The higher ohms will give you less volume though... I think it is OK to go from 2-8 ohms with a tube amp with its optimal operating range being 4 ohms. I know with my gear I would follow manufacturers spec so it will last... I think Jim Shank use to run his twin with a higher ohm rating sometimes and only mentioned the drop in volume, so instead of being on 3 you will be on 5. I think you really don't want to go lower than 4 but higher is not an issue. I could be wrong, so double check it.

My Amp is a 4 ohm output my speakers are 16ohm speakers. Everyone i have asked said with a tube amp this is not a good idea. Im so lost lol i know i should be matching the amp with the speakers ohm wise, but im kinda stuck dealing with what i am dealing with. So its not a good idea to push 4 ohm's into the 2 16ohm speakers with my Hot Rod Deville ?

-Walt
 #101285  by strumminsix
 Thu Jul 21, 2011 6:28 pm
inthedark wrote:
JonnyBoy wrote:I think at 8 ohms with a twin you are OK, you can run another 8 ohm speaker in a separate cab and get the 4 ohms... The higher ohms will give you less volume though... I think it is OK to go from 2-8 ohms with a tube amp with its optimal operating range being 4 ohms. I know with my gear I would follow manufacturers spec so it will last... I think Jim Shank use to run his twin with a higher ohm rating sometimes and only mentioned the drop in volume, so instead of being on 3 you will be on 5. I think you really don't want to go lower than 4 but higher is not an issue. I could be wrong, so double check it.

My Amp is a 4 ohm output my speakers are 16ohm speakers. Everyone i have asked said with a tube amp this is not a good idea. Im so lost lol i know i should be matching the amp with the speakers ohm wise, but im kinda stuck dealing with what i am dealing with. So its not a good idea to push 4 ohm's into the 2 16ohm speakers with my Hot Rod Deville ?

-Walt
Your amp is a Deville, yes? So it has a much smaller OT than a Twin. Ohms is an electrical measure of resistance. Your amps OT (output transformer) is prepared to push a signal with against 4 ohms of resistance. So the 8 ohms will make it work harder. MANY folks say 1 mismatch down (2.6 ohms) or up (8 ohms) is usually safe.

In my mind your best option is to sell the speakers and buy the proper pair. Sorry to say that. If not, some sort of device like you mentioned above. I would not gig long term with those speakers in your amp as you are making the amp work harder against a larger load than designed.
 #101286  by inthedark
 Thu Jul 21, 2011 6:43 pm
strumminsix wrote:
inthedark wrote:
JonnyBoy wrote:I think at 8 ohms with a twin you are OK, you can run another 8 ohm speaker in a separate cab and get the 4 ohms... The higher ohms will give you less volume though... I think it is OK to go from 2-8 ohms with a tube amp with its optimal operating range being 4 ohms. I know with my gear I would follow manufacturers spec so it will last... I think Jim Shank use to run his twin with a higher ohm rating sometimes and only mentioned the drop in volume, so instead of being on 3 you will be on 5. I think you really don't want to go lower than 4 but higher is not an issue. I could be wrong, so double check it.

My Amp is a 4 ohm output my speakers are 16ohm speakers. Everyone i have asked said with a tube amp this is not a good idea. Im so lost lol i know i should be matching the amp with the speakers ohm wise, but im kinda stuck dealing with what i am dealing with. So its not a good idea to push 4 ohm's into the 2 16ohm speakers with my Hot Rod Deville ?

-Walt
Your amp is a Deville, yes? So it has a much smaller OT than a Twin. Ohms is an electrical measure of resistance. Your amps OT (output transformer) is prepared to push a signal with against 4 ohms of resistance. So the 8 ohms will make it work harder. MANY folks say 1 mismatch down (2.6 ohms) or up (8 ohms) is usually safe.

In my mind your best option is to sell the speakers and buy the proper pair. Sorry to say that. If not, some sort of device like you mentioned above. I would not gig long term with those speakers in your amp as you are making the amp work harder against a larger load than designed.
Thanks :-) I am going to order that Weber device and see how it goes. Stinks the speakers are what i want and Mark was nice enough to sign them for me as well. I will post a review of the Weber unit once i get it. Thanks again everyone for all the responses :-)

-Walt
 #101294  by strumminsix
 Fri Jul 22, 2011 5:54 am
I don't know why I totally spaced this last night but her goes... You could have your amp modified with a new OT to handle the 8 ohm load. Or even a few taps. Should be about a $200 job, IIRC.
 #101307  by hippieguy1954
 Fri Jul 22, 2011 11:05 am
strumminsix wrote:I don't know why I totally spaced this last night but her goes... You could have your amp modified with a new OT to handle the 8 ohm load. Or even a few taps. Should be about a $200 job, IIRC.
Strumminsix! That's a great idea. It's either that or get the correct speakers. I wouldn't bother with another piece of equiptment though. Personally, if it was me when I was a lot younger, I'd play those speakers in that amp just to see if I could make it smoke! :smile: :smile: :smile:
 #101311  by inthedark
 Fri Jul 22, 2011 12:02 pm
hippieguy1954 wrote:
strumminsix wrote:I don't know why I totally spaced this last night but her goes... You could have your amp modified with a new OT to handle the 8 ohm load. Or even a few taps. Should be about a $200 job, IIRC.
Strumminsix! That's a great idea. It's either that or get the correct speakers. I wouldn't bother with another piece of equiptment though. Personally, if it was me when I was a lot younger, I'd play those speakers in that amp just to see if I could make it smoke! :smile: :smile: :smile:

The Weber device though would be universal with all the amps and cabs i have so i could play any amp through any of my cabs i have regardless of ohm rating. All my cabs can handle the wattage just fine but i have 4ohm, 8ohm and 16ohm speakers lol so this device for my situation is perfect. I'd rather spend $110 then $200 currently as im short on cash these past few months.

-Walt