Radio/Speaker/Ohm Question
Thread Starter
Racer
Joined: Dec 2013
Posts: 307
Likes: 15
From: Marlboro New Jersey
Radio/Speaker/Ohm Question
Question for those who know more than I do, which includes everybody and everybody. I plan to keep the original 10 ohm radio but want to upgrade the speakers (don't need to be in-dash). I understand that I cannot use the modern 4 ohm speakers, however a tech at Crutchfield just told me that if I run the radio thru an amp (which is 4 ohms) to the speakers, I can use the 4 ohm speakers, in which case I have my choice of speakers. Is this advice correct? Thanks for any help/suggestions. 
Burning Brakes
Joined: Aug 2009
Posts: 941
Likes: 3
From: Columbus OH
Hi, The advice is mostly right , but depends on the AMP.
Many AMP's can accept a low voltage RCA pre-amp signal OR a powered signal. Your radio, even at 10 ohms, is still a powered signal so make sure you get an AMP that has the 'powered input' option, not just the RCA pre-amp connection. Then, you can connect the modern 4-ohm speakers to the outputs intuitively.
Another crazy option is to add a bunch more speakers.
If you wire two modern 4-ohm speakers in a daisy-chain (series configuration) it makes 8 ohms. If you take another two modern 4-ohm speakers and wire them side-by-side ( parallel configuration ) it reduces their resistance to 2 ohms. If you take the first set of 2 and wire them in series with the second set of two, you get 10 ohms.
Assuming your dash head unit is stereo that would mean 4 speakers total for the left side, and another 4 for the right. 8 speakers total that you could find clever places to mount throughout the car.
The volume of such a configuration won't be rock concert level since the head unit is not so modern, but it works.
Many AMP's can accept a low voltage RCA pre-amp signal OR a powered signal. Your radio, even at 10 ohms, is still a powered signal so make sure you get an AMP that has the 'powered input' option, not just the RCA pre-amp connection. Then, you can connect the modern 4-ohm speakers to the outputs intuitively.
Another crazy option is to add a bunch more speakers.
If you wire two modern 4-ohm speakers in a daisy-chain (series configuration) it makes 8 ohms. If you take another two modern 4-ohm speakers and wire them side-by-side ( parallel configuration ) it reduces their resistance to 2 ohms. If you take the first set of 2 and wire them in series with the second set of two, you get 10 ohms.
Assuming your dash head unit is stereo that would mean 4 speakers total for the left side, and another 4 for the right. 8 speakers total that you could find clever places to mount throughout the car.
The volume of such a configuration won't be rock concert level since the head unit is not so modern, but it works.
Thread Starter
Racer
Joined: Dec 2013
Posts: 307
Likes: 15
From: Marlboro New Jersey
Hi, The advice is mostly right , but depends on the AMP.
Many AMP's can accept a low voltage RCA pre-amp signal OR a powered signal. Your radio, even at 10 ohms, is still a powered signal so make sure you get an AMP that has the 'powered input' option, not just the RCA pre-amp connection. Then, you can connect the modern 4-ohm speakers to the outputs intuitively.
Another crazy option is to add a bunch more speakers.
If you wire two modern 4-ohm speakers in a daisy-chain (series configuration) it makes 8 ohms. If you take another two modern 4-ohm speakers and wire them side-by-side ( parallel configuration ) it reduces their resistance to 2 ohms. If you take the first set of 2 and wire them in series with the second set of two, you get 10 ohms.
Assuming your dash head unit is stereo that would mean 4 speakers total for the left side, and another 4 for the right. 8 speakers total that you could find clever places to mount throughout the car.
The volume of such a configuration won't be rock concert level since the head unit is not so modern, but it works.
Many AMP's can accept a low voltage RCA pre-amp signal OR a powered signal. Your radio, even at 10 ohms, is still a powered signal so make sure you get an AMP that has the 'powered input' option, not just the RCA pre-amp connection. Then, you can connect the modern 4-ohm speakers to the outputs intuitively.
Another crazy option is to add a bunch more speakers.
If you wire two modern 4-ohm speakers in a daisy-chain (series configuration) it makes 8 ohms. If you take another two modern 4-ohm speakers and wire them side-by-side ( parallel configuration ) it reduces their resistance to 2 ohms. If you take the first set of 2 and wire them in series with the second set of two, you get 10 ohms.
Assuming your dash head unit is stereo that would mean 4 speakers total for the left side, and another 4 for the right. 8 speakers total that you could find clever places to mount throughout the car.
The volume of such a configuration won't be rock concert level since the head unit is not so modern, but it works.
Le Mans Master
Joined: Feb 2011
Posts: 5,943
Likes: 61
From: Southern NH
Thread Starter
Racer
Joined: Dec 2013
Posts: 307
Likes: 15
From: Marlboro New Jersey
Thanks for the response.
Le Mans Master
Joined: May 2003
Posts: 8,877
Likes: 3,556
From: Fernandina Beach FL
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
Here's the problem- Garbage in- Garbage out. Unfortunately that old radio is not really going to sound any better even if you hook up some really really nice speakers....And the amplifier will just make the sound louder not better,
I'd just keep it simple and go w/ the 10Ω speakers...
Richard
Burning Brakes
Joined: Sep 2013
Posts: 1,206
Likes: 365
From: The Motor City
What Hyteck said- or you can buy a "low level to line adapter" - less than $15. Will take the speaker level and convert it to a preamp level RCA jacks. Then you can use any amp.
Here's the problem- Garbage in- Garbage out. Unfortunately that old radio is not really going to sound any better even if you hook up some really really nice speakers....And the amplifier will just make the sound louder not better,
I'd just keep it simple and go w/ the 10Ω speakers...
Richard
Here's the problem- Garbage in- Garbage out. Unfortunately that old radio is not really going to sound any better even if you hook up some really really nice speakers....And the amplifier will just make the sound louder not better,
I'd just keep it simple and go w/ the 10Ω speakers...
Richard
Dave
Dave
Thread Starter
Racer
Joined: Dec 2013
Posts: 307
Likes: 15
From: Marlboro New Jersey
Richard, I can tell you from personal experience that that is simply not a true statement. I believe you that it used to be true, but technology has finally caught up. I installed a 300W amp that neatly fits under the OE radio chassis in the console, and top of the line Alpine SPR-69 speakers (no others will fit in the factory 6x9 mount); 4x6 Polks in the front. When you use a cassette adapter ($10) and hook it to your iPod it sounds incredible. My wife and I cannot get over it. You hear all the nuances in the music. The main trade-off is that the radio reception, even though it is the original equipment electronic tuner model, it does not hold a station quite as good as a modern day radio - and, the separation is not quite as good, but you can definitely hear the separation on sounds produced with front to back and left to right arrangements - including, even in the 70's and 80's music that we thoroughly enjoy. But, I am so glad that I did it, exceeding my every hope from a sound quality, and stock packaging standpoint. I just have to get my front-to-rear fade function to work now, and by installing the Hi-to-low wire converter to RCA plugs I am told by a fellow forum brother that that will take care of that, too.
Dave
Dave
Dave
Dave
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Le Mans Master
Joined: May 2003
Posts: 8,877
Likes: 3,556
From: Fernandina Beach FL
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
Richard, I can tell you from personal experience that that is simply not a true statement. I believe you that it used to be true, but technology has finally caught up. I installed a 300W amp that neatly fits under the OE radio chassis in the console, and top of the line Alpine SPR-69 speakers (no others will fit in the factory 6x9 mount); 4x6 Polks in the front. When you use a cassette adapter ($10) and hook it to your iPod it sounds incredible. My wife and I cannot get over it. You hear all the nuances in the music. The main trade-off is that the radio reception, even though it is the original equipment electronic tuner model, it does not hold a station quite as good as a modern day radio - and, the separation is not quite as good, but you can definitely hear the separation on sounds produced with front to back and left to right arrangements - including, even in the 70's and 80's music that we thoroughly enjoy. But, I am so glad that I did it, exceeding my every hope from a sound quality, and stock packaging standpoint. I just have to get my front-to-rear fade function to work now, and by installing the Hi-to-low wire converter to RCA plugs I am told by a fellow forum brother that that will take care of that, too.
Dave
Dave
Dave
Dave
http://forums.corvetteforum.com/1587308416-post7.html
I have some personal experience...mostly professional dealing w/ Car Audio for 20 years.... Glad it worked out for you.
Richard
Burning Brakes
Joined: Sep 2013
Posts: 1,206
Likes: 365
From: The Motor City
Ummm...FWIW -I'm the fellow forum member that recommended the line level... Did you try just the positive speaker leads of the radio- since the speaker's negative is common w/ the radios ground?
http://forums.corvetteforum.com/1587308416-post7.html
I have some personal experience...mostly professional dealing w/ Car Audio for 20 years.... Glad it worked out for you.
Richard
http://forums.corvetteforum.com/1587308416-post7.html
I have some personal experience...mostly professional dealing w/ Car Audio for 20 years.... Glad it worked out for you.
Richard
I'll let you know what I find when I get back from an upcoming trip and will have a chance to go back into the console/radio (btw, do you know who sells those radio **** nut removal tool?)
Regarding the common ground, the rear speakers are mounted in plastic and not grounded to the body. Will that make any difference?
Le Mans Master
Joined: May 2003
Posts: 8,877
Likes: 3,556
From: Fernandina Beach FL
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
You're one of the original good guys. I really appreciated your insights.
I'll let you know what I find when I get back from an upcoming trip and will have a chance to go back into the console/radio (btw, do you know who sells those radio **** nut removal tool?)
Regarding the common ground, the rear speakers are mounted in plastic and not grounded to the body. Will that make any difference?
I'll let you know what I find when I get back from an upcoming trip and will have a chance to go back into the console/radio (btw, do you know who sells those radio **** nut removal tool?)
Regarding the common ground, the rear speakers are mounted in plastic and not grounded to the body. Will that make any difference?
As far as the ground- speaker negatives- I'm just talking about the head unit or Radio.
An amplifier (very few exceptions) will not work if the negative speaker lead is grounded- or using the chassis ground.
Older radios were 'common ground'- newer ones 'floating ground.'
Tho determine what type you have-
Make sure the Radio off. Set the meter to ohms. Touch the black probe to the metal case of the Radio and the red probe to the negative speaker wires. If you read anything near 0 ohms, the head unit has a common ground.
Richard
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
The original Delco radio had "common" grounds for the head unit and speakers; all of them could be tied together and routed to chassis/battery ground.
Newer head units need a 'chassis ground' for the head unit; but the speakers are 'floating' units and the negative connection should NOT be routed to ground or tied to each other.
If you keep the Delco head unit and feed newer speakers directly, all negative connections should be tie collectively.
If you feed the Delco head into a modern amp unit, the amp will have a chassis ground wire; but the speakers will have + and - wires coming from the amp and the negative speaker connections will NOT be tied to chassis ground.
Newer head units need a 'chassis ground' for the head unit; but the speakers are 'floating' units and the negative connection should NOT be routed to ground or tied to each other.
If you keep the Delco head unit and feed newer speakers directly, all negative connections should be tie collectively.
If you feed the Delco head into a modern amp unit, the amp will have a chassis ground wire; but the speakers will have + and - wires coming from the amp and the negative speaker connections will NOT be tied to chassis ground.
Instructor
Joined: Jan 2013
Posts: 155
Likes: 2
From: Naples Florida
The original Delco radio had "common" grounds for the head unit and speakers; all of them could be tied together and routed to chassis/battery ground.
Newer head units need a 'chassis ground' for the head unit; but the speakers are 'floating' units and the negative connection should NOT be routed to ground or tied to each other.
If you keep the Delco head unit and feed newer speakers directly, all negative connections should be tie collectively.
If you feed the Delco head into a modern amp unit, the amp will have a chassis ground wire; but the speakers will have + and - wires coming from the amp and the negative speaker connections will NOT be tied to chassis ground.
Newer head units need a 'chassis ground' for the head unit; but the speakers are 'floating' units and the negative connection should NOT be routed to ground or tied to each other.
If you keep the Delco head unit and feed newer speakers directly, all negative connections should be tie collectively.
If you feed the Delco head into a modern amp unit, the amp will have a chassis ground wire; but the speakers will have + and - wires coming from the amp and the negative speaker connections will NOT be tied to chassis ground.
Will provide feed back.
Thanks
Max
Le Mans Master
Joined: Sep 2003
Posts: 8,812
Likes: 2,029
From: eastern NC
You're one of the original good guys. I really appreciated your insights.
I'll let you know what I find when I get back from an upcoming trip and will have a chance to go back into the console/radio (btw, do you know who sells those radio **** nut removal tool?)
Regarding the common ground, the rear speakers are mounted in plastic and not grounded to the body. Will that make any difference?
I'll let you know what I find when I get back from an upcoming trip and will have a chance to go back into the console/radio (btw, do you know who sells those radio **** nut removal tool?)
Regarding the common ground, the rear speakers are mounted in plastic and not grounded to the body. Will that make any difference?
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http://store.snapon.com/Mirror-and-R...t-P636323.aspx
Purchased mine more than 40 years ago and now I only get to use it on my "old" Corvette.
Good luck... GUSTO