Oh My Ohms...........
04-18-2002, 10:27 PM
#1
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Join Date: May 2001
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Oh My Ohms...........
I'm taking electricity and magnetism in college now and i'm still so lost.....
i just bought 2 RF 10's which are 4 ohms each, 100 watts RMS, 200 watts peak...
my amp is the RF 300S...which is:
75W x 2 for 4 ohms per channel
150W x 2 for 2 ohms per channel
300W x 1 for 4 ohms bridged (mono)
i was under the impression i would wire the speakers in parallel and it would bring the resistance down from 4 to 2 and then i'd pull 150W to each channel (each speaker) from the amp...will this work?...the box has two connecting places and the amp has two speaker terminals so what would my wiring look like???
please...if you know what you're talking about then please help me out
thanks
adrian
i just bought 2 RF 10's which are 4 ohms each, 100 watts RMS, 200 watts peak...
my amp is the RF 300S...which is:
75W x 2 for 4 ohms per channel
150W x 2 for 2 ohms per channel
300W x 1 for 4 ohms bridged (mono)
i was under the impression i would wire the speakers in parallel and it would bring the resistance down from 4 to 2 and then i'd pull 150W to each channel (each speaker) from the amp...will this work?...the box has two connecting places and the amp has two speaker terminals so what would my wiring look like???
please...if you know what you're talking about then please help me out
thanks
adrian
04-18-2002, 10:56 PM
#2
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Nope, won't work. Your max power will be 75 X 2. You have two 4 ohm subs. Parallel will be a two ohm load. But the amp can not be bridged into a two ohm load. The lowest it is stable is 4 ohms bridged. If you connect the subs in series you will have an 8 ohm load. If you then bridge the amp it will see the load the same as it see's a 4 ohm stereo load. So bridged output would only be 150 watts. But if the subs are only rated for 100 watts, 75 should be plenty.
04-18-2002, 11:07 PM
#3
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Posts: 482
just for the sake of stating it, the old punch XXXa2's and punch XXXa4's were capable of 1.33 ohms stereo, or 2.67 ohm mono. the power XXXa2's and power XXXa4's were 1 ohm stereo, 2 ohm mono stable.this information came directly from a rockford dealer (and theyre not gonna tell ya theyre stable lower than they are, cuz then you got to deal with returns, ect.
jmax, that wasnt to take away from what you said, just stating applicable info.
eric
04-19-2002, 06:29 AM
#4
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Rockford is making a steady decline in my opinion....The xxx.a2 and xxx.a4 series were the last really strong amps to come from them. Now they are targeting mass retail sales. BBY and Crutchfield are their biggest markets so they are focusing on production more than quality. I think their flagship amps(anything over 400-500 retail) are still decent but their lower/mid range models that the sell tons of are starting to see a quality loss.
Warbucks
Warbucks
04-19-2002, 06:48 AM
#5
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Posts: 198
Originally posted by nismo240sx
just for the sake of stating it, the old punch XXXa2's and punch XXXa4's were capable of 1.33 ohms stereo, or 2.67 ohm mono. the power XXXa2's and power XXXa4's were 1 ohm stereo, 2 ohm mono stable.
this information came directly from a rockford dealer (and theyre not gonna tell ya theyre stable lower than they are, cuz then you got to deal with returns, ect.
jmax, that wasnt to take away from what you said, just stating applicable info.
eric
just for the sake of stating it, the old punch XXXa2's and punch XXXa4's were capable of 1.33 ohms stereo, or 2.67 ohm mono. the power XXXa2's and power XXXa4's were 1 ohm stereo, 2 ohm mono stable.this information came directly from a rockford dealer (and theyre not gonna tell ya theyre stable lower than they are, cuz then you got to deal with returns, ect.
jmax, that wasnt to take away from what you said, just stating applicable info.
eric
grrrrrrr,
adrian
04-19-2002, 01:32 PM
#6
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Posts: 3,445
Originally posted by MaxSport730
ok...so i'm really disapointed...cause now i have to run my amp at full power just to get 3/4's of the rms on the subs...which is something i def don't want to do...its past the return time for the subs (i bought it at 6th ave electronics) and i don't want to buy a more expensive amp...what's this that nismo240sx was talking about???...does this offer solution to my problem?...if not is there ANY solution???
grrrrrrr,
adrian
ok...so i'm really disapointed...cause now i have to run my amp at full power just to get 3/4's of the rms on the subs...which is something i def don't want to do...its past the return time for the subs (i bought it at 6th ave electronics) and i don't want to buy a more expensive amp...what's this that nismo240sx was talking about???...does this offer solution to my problem?...if not is there ANY solution???
grrrrrrr,
adrian
04-19-2002, 01:33 PM
#7
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Join Date: Jun 2001
Posts: 3,445
Originally posted by MaxSport730
ok...so i'm really disapointed...cause now i have to run my amp at full power just to get 3/4's of the rms on the subs...which is something i def don't want to do...its past the return time for the subs (i bought it at 6th ave electronics) and i don't want to buy a more expensive amp...what's this that nismo240sx was talking about???...does this offer solution to my problem?...if not is there ANY solution???
grrrrrrr,
adrian
ok...so i'm really disapointed...cause now i have to run my amp at full power just to get 3/4's of the rms on the subs...which is something i def don't want to do...its past the return time for the subs (i bought it at 6th ave electronics) and i don't want to buy a more expensive amp...what's this that nismo240sx was talking about???...does this offer solution to my problem?...if not is there ANY solution???
grrrrrrr,
adrian
NO
04-19-2002, 01:58 PM
#8
ok, here's my take on it. what jmax said is correct. i'd wire the subs in series to produce an 8 ohm load, i'd then go ahead and bridge the amp, the amp would then see a 4ohm load. each sub would get around 150, which sounds about right to me, for the spec you listed.
04-21-2002, 10:06 AM
#9
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Originally posted by victor
ok, here's my take on it. what jmax said is correct. i'd wire the subs in series to produce an 8 ohm load, i'd then go ahead and bridge the amp, the amp would then see a 4ohm load. each sub would get around 150, which sounds about right to me, for the spec you listed.
ok, here's my take on it. what jmax said is correct. i'd wire the subs in series to produce an 8 ohm load, i'd then go ahead and bridge the amp, the amp would then see a 4ohm load. each sub would get around 150, which sounds about right to me, for the spec you listed.
04-21-2002, 11:11 AM
#10
Originally posted by jmax
Nope, total output of the amp will be 150 watts. 75 per sub. But the rockford probably puts out at least a little more than the rated 75 RMS. But definitely not like in the 1980's and early to mid '90's RF amps.
Nope, total output of the amp will be 150 watts. 75 per sub. But the rockford probably puts out at least a little more than the rated 75 RMS. But definitely not like in the 1980's and early to mid '90's RF amps.
04-21-2002, 05:26 PM
#13
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Originally posted by victor
oh. i thought that the amp would see the 4ohm bridged load, so it would put out 300 x1. i'm confused now.
oh. i thought that the amp would see the 4ohm bridged load, so it would put out 300 x1. i'm confused now.
Two 4ohm subs in series = 8 ohm. Bridged at 8ohm, each amp channel "see's" 4ohm (pushes 75w each). Since the amp is rated at 2x75@4ohm/chnl, total bridged output to the subs will be 150w. Since you have two subs, each sub would receive 75w. Same as if you ran both subs in stereo (one sub per channel).
Now, if you simply bridge the amp and connect one sub, (4 ohm bridged), each channel "see's" 2ohm. So, bridged output will then be 300w (150+150).
Does that help?
04-22-2002, 05:09 AM
#14
Originally posted by Audtatious
Nope...
Two 4ohm subs in series = 8 ohm. Bridged at 8ohm, each amp channel "see's" 4ohm (pushes 75w each). Since the amp is rated at 2x75@4ohm/chnl, total bridged output to the subs will be 150w. Since you have two subs, each sub would receive 75w. Same as if you ran both subs in stereo (one sub per channel).
Now, if you simply bridge the amp and connect one sub, (4 ohm bridged), each channel "see's" 2ohm. So, bridged output will then be 300w (150+150).
Does that help?
Nope...
Two 4ohm subs in series = 8 ohm. Bridged at 8ohm, each amp channel "see's" 4ohm (pushes 75w each). Since the amp is rated at 2x75@4ohm/chnl, total bridged output to the subs will be 150w. Since you have two subs, each sub would receive 75w. Same as if you ran both subs in stereo (one sub per channel).
Now, if you simply bridge the amp and connect one sub, (4 ohm bridged), each channel "see's" 2ohm. So, bridged output will then be 300w (150+150).
Does that help?
04-23-2002, 05:01 AM
#15
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Join Date: May 2001
Posts: 198
Originally posted by Audtatious
Nope...
Two 4ohm subs in series = 8 ohm. Bridged at 8ohm, each amp channel "see's" 4ohm (pushes 75w each). Since the amp is rated at 2x75@4ohm/chnl, total bridged output to the subs will be 150w. Since you have two subs, each sub would receive 75w. Same as if you ran both subs in stereo (one sub per channel).
Now, if you simply bridge the amp and connect one sub, (4 ohm bridged), each channel "see's" 2ohm. So, bridged output will then be 300w (150+150).
Does that help?
Nope...
Two 4ohm subs in series = 8 ohm. Bridged at 8ohm, each amp channel "see's" 4ohm (pushes 75w each). Since the amp is rated at 2x75@4ohm/chnl, total bridged output to the subs will be 150w. Since you have two subs, each sub would receive 75w. Same as if you ran both subs in stereo (one sub per channel).
Now, if you simply bridge the amp and connect one sub, (4 ohm bridged), each channel "see's" 2ohm. So, bridged output will then be 300w (150+150).
Does that help?
04-23-2002, 05:38 AM
#16
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Originally posted by MaxSport730
Now i totally get it!...but if i bridge then it sends 75watts to each speaker and if i use each channel it sends 75 watts to each speaker...what's the difference between wiring it the two dif ways
Now i totally get it!...but if i bridge then it sends 75watts to each speaker and if i use each channel it sends 75 watts to each speaker...what's the difference between wiring it the two dif ways
04-23-2002, 10:41 AM
#20
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In mono the amp will sum the signals. So the net output will be the same either way. Look at it this way: If a low bass note hits (at full output in the digital domain) in only the left channel in stereo the left sub will play that note at the full power capability of the amp/sub. In mono the left channel signal is combined with the right channel signal and averaged. So a full output signal averaged with a null signal would reproduce a half power signal going to both subs.
Since sub bass is non-directional you can't tell whether it is coming from the left or right sub. So there is no benefit to using a stereo signal. But no loss of sound SQ or SPL by connecting in stereo. "6 one way, a half dozen the other."
Since sub bass is non-directional you can't tell whether it is coming from the left or right sub. So there is no benefit to using a stereo signal. But no loss of sound SQ or SPL by connecting in stereo. "6 one way, a half dozen the other."
04-24-2002, 06:06 AM
#21
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Originally posted by jmax
In mono the amp will sum the signals. So the net output will be the same either way. Look at it this way: If a low bass note hits (at full output in the digital domain) in only the left channel in stereo the left sub will play that note at the full power capability of the amp/sub. In mono the left channel signal is combined with the right channel signal and averaged. So a full output signal averaged with a null signal would reproduce a half power signal going to both subs.
Since sub bass is non-directional you can't tell whether it is coming from the left or right sub. So there is no benefit to using a stereo signal. But no loss of sound SQ or SPL by connecting in stereo. "6 one way, a half dozen the other."
In mono the amp will sum the signals. So the net output will be the same either way. Look at it this way: If a low bass note hits (at full output in the digital domain) in only the left channel in stereo the left sub will play that note at the full power capability of the amp/sub. In mono the left channel signal is combined with the right channel signal and averaged. So a full output signal averaged with a null signal would reproduce a half power signal going to both subs.
Since sub bass is non-directional you can't tell whether it is coming from the left or right sub. So there is no benefit to using a stereo signal. But no loss of sound SQ or SPL by connecting in stereo. "6 one way, a half dozen the other."
Warbucks
04-24-2002, 11:24 AM
#22
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Should work just fine. I would highly suggest using a low xover setting to avoid stereo mid-bass (it could happen 
) from distorting the sub....Of course, a mono input to the amp is always preferred if you are not bridging.
) from distorting the sub....Of course, a mono input to the amp is always preferred if you are not bridging.
04-26-2002, 11:22 AM
#23
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Originally posted by Audtatious
Should work just fine. I would highly suggest using a low xover setting to avoid stereo mid-bass (it could happen ) from distorting the sub....Of course, a mono input to the amp is always preferred if you are not bridging.
Should work just fine. I would highly suggest using a low xover setting to avoid stereo mid-bass (it could happen
) from distorting the sub....Of course, a mono input to the amp is always preferred if you are not bridging.
Warbucks