I am buying subs tomorow for my car since today is my birthday. I have heard, both from different authourized alpine dealers, that my rockford fosgate punch 801s amplifier can and can not supply enough power for 2 swr1221d subs. those are alpine type r's dual subs at 2 ohms. i am listing the specs of both my amp and the type r and type s subs. please give me your opinion on which sub you think i should get. I have been offered prices and these are the best: 2 type r's and an alpine enclosure for 300$ installed, out the door. and 2 type s and an alpine enclosure for 240$.
please keep in mind i dont want to over heat my amp or underpower my subs so i need it best fit as possible. thanks.
ROCKFORD 801S amp specs:
2400 watts max
400watts rms X 2 at 2 ohm
200 watts rms X2 at 4 ohm
TYPE R(swr1221d):
1000 watts max
300 watts rms
TYPE S (sws1222d):
900 watts max
300 watts rms
Replies (7)
uochronos on 10/17/2004 21:30:28
this amp can power either subs just make sure you get 4+4ohm dvc subs. wire each sub at 2ohm and then to the amp each sub well get 400watts of clean power.
Chronos
Victor on 10/17/2004 21:44:22
well i have used neither of them.. but the type R and type S both have dual 2 ohms voice coils.. but since alpine says the type R are the more advanced ones i feel they must be better.. regarding the amp .. i feel it can take both of them equally well. .. as far as you get the wiring right.. what u shud do is wire both the voice coils( of both the woofers ) in series that way u can get a load of 4 ohms per woofer.. and then wire the woofers in parallel or wire the voice coils in parallel and then the woofers in series.. that can get u a load of 2 ohms..which i feel the Rockford 801S can easily take and perform powerfully well.. if u r planning to bridge the amp then be careful in wiring the subs cause the amp is stable at 4 ohms in bridged mode.. it wont perform with a load of 2 ohms.. so what u can do if u wanna bridge is. ..wire the voice coil of one of the woofer in series and the other in parallel.. that will give u a load of 4 ohms for the series wired coils and 1 ohm for the parallel wired coils.. then wire the woofers in series to give u a total load of 5ohms.. at this load the amp will give something near 650-700 w rms( mono).
uochronos on 10/17/2004 22:08:14
your idea on wiring is a bit strange but since he well likly buy the 4+4dvc subs he can either wire each sub as i listed above or bridge the amp and wire the subs in series parrelel.
i know alpine makes 4+4DVC because i own a set. and that makes wireing options much more usefull then a 2+2dvc subs.
Chronos
Victor on 10/17/2004 22:19:21
yeah.. i know everyone here wud say its strange.. one more thing.,.. no hard feelings but u better check out the sub details.. cause both the subs have dual 2ohms voice coils.. thats why i had to suggest the strange kind of wiring.. orelse if he uses subs with 4 ohms voice coils then its a pretty simple installation.
uochronos on 10/17/2004 22:29:04
the 2 he listed where the 2+2dvc versions they make both 2+2dvc and 4+4dvc i'm looking at the site right now. and its not that i think your wiring is strange its that there is a simplere safer way to do it. and net same results.
P0werLifter on 10/17/2004 22:33:03
The RF 801S will power these subwoofers fine at the 2ohm load range just fine. I'd reccomend going with the Type R's and depending on if you want loud, boomy bass with very good low end go with a ported enclosure, or for tight bass go with a sealed enclosure
One concern i have for you though is your stock automobiles electrical capacity. Since your going to be running dual subs..each at 400watts RMS thats an 800watt load for your alternator to keep up with.
Stock American Automobiles come with <105amp alternators on average. It takes 50-60amperes to run stock electricals (IE. heater, Ac, Fan, Lights, etc.) that leaves you with 40-50amperes to play around with, without having to upgrade your electricals to support the new load.
In order to figure out the amperage load your new system will have, get the total wattage of your system, divided by the amplifiers efficiency factor, divided by the charging voltage (13.5V good average number). For this ill just use the RMS value for your as your RMS value is 800watts....800/.5 (Class AB amplifiers run at about 50% efficient) 800/.5 = 1600....1600/13.5= 118amperage load for this type of amplifier. For subwoofer applications we reccomend going with a class D mono amplifier. These run at about 90% efficient while still producing massive wattage.
Now tack on the 60amperes for your stock electricals on top of the 118amp load...BAM 178amp alternator you need. The whole electrical upgrade process including a battery will run you >$500 then tack on on wiring costs, pans out to be rather expensive
Im not trying to discourage you, just merely informing you of the possible problems you could run into with running a larger 2channel AB amplifier. If you can get a hold of a 800watt MONO amp that would help you out. 800/.9=888amperes. 888/13.5= 65.5amper load....65.5+60= 125amp alternator. With the MONO block amplifier you might get by with running a battery with >850CCA and upgrading your Alt-Bat, Bat-Ground, Engine-Chassis wires.
Hope this helps ya out.
-Jason
Relax_The_Mind on 10/18/2004 11:30:38
That amp is more than enough to push those subs.
In simple... get the dual 4 ohm models. Parallel the voice coils to 2 ohms and run them to the individual left and right channels. 2 dual 2ohm subs work best with a mono amp that is 2ohm stable.
Quote Victor
"{what u shud do is wire both the voice coils( of both the woofers ) in series that way u can get a load of 4 ohms per woofer.. and then wire the woofers in parallel or wire the voice coils in parallel and then the woofers in series.. that can get u a load of 2 ohms..}"
That sounds strange because the only way you could use 2 ohms on that amp is unbridged to one channel.
Quote Victor
"{wire the voice coil of one of the woofer in series and the other in parallel.. that will give u a load of 4 ohms for the series wired coils and 1 ohm for the parallel wired coils.. then wire the woofers in series to give u a total load of 5ohms.. at this load the amp will give something near 650-700 w rms( mono)}"
That would not work either as that would be giving one speaker 75% of the power and the other speaker 25%. Which would cause one of both speakers to blow . You must match the impedance of each speaker as power is dropped across a speaker according to its resistence. Yes it is strange.
vicflo
please keep in mind i dont want to over heat my amp or underpower my subs so i need it best fit as possible. thanks.
ROCKFORD 801S amp specs:
2400 watts max
400watts rms X 2 at 2 ohm
200 watts rms X2 at 4 ohm
TYPE R(swr1221d):
1000 watts max
300 watts rms
TYPE S (sws1222d):
900 watts max
300 watts rms
Replies (7)
uochronos on 10/17/2004 21:30:28
this amp can power either subs just make sure you get 4+4ohm dvc subs. wire each sub at 2ohm and then to the amp each sub well get 400watts of clean power.
Chronos
Victor on 10/17/2004 21:44:22
well i have used neither of them.. but the type R and type S both have dual 2 ohms voice coils.. but since alpine says the type R are the more advanced ones i feel they must be better.. regarding the amp .. i feel it can take both of them equally well. .. as far as you get the wiring right.. what u shud do is wire both the voice coils( of both the woofers ) in series that way u can get a load of 4 ohms per woofer.. and then wire the woofers in parallel or wire the voice coils in parallel and then the woofers in series.. that can get u a load of 2 ohms..which i feel the Rockford 801S can easily take and perform powerfully well.. if u r planning to bridge the amp then be careful in wiring the subs cause the amp is stable at 4 ohms in bridged mode.. it wont perform with a load of 2 ohms.. so what u can do if u wanna bridge is. ..wire the voice coil of one of the woofer in series and the other in parallel.. that will give u a load of 4 ohms for the series wired coils and 1 ohm for the parallel wired coils.. then wire the woofers in series to give u a total load of 5ohms.. at this load the amp will give something near 650-700 w rms( mono).
uochronos on 10/17/2004 22:08:14
your idea on wiring is a bit strange but since he well likly buy the 4+4dvc subs he can either wire each sub as i listed above or bridge the amp and wire the subs in series parrelel.
i know alpine makes 4+4DVC because i own a set. and that makes wireing options much more usefull then a 2+2dvc subs.
Chronos
Victor on 10/17/2004 22:19:21
yeah.. i know everyone here wud say its strange.. one more thing.,.. no hard feelings but u better check out the sub details.. cause both the subs have dual 2ohms voice coils.. thats why i had to suggest the strange kind of wiring.. orelse if he uses subs with 4 ohms voice coils then its a pretty simple installation.
uochronos on 10/17/2004 22:29:04
the 2 he listed where the 2+2dvc versions they make both 2+2dvc and 4+4dvc i'm looking at the site right now. and its not that i think your wiring is strange its that there is a simplere safer way to do it. and net same results.
P0werLifter on 10/17/2004 22:33:03
The RF 801S will power these subwoofers fine at the 2ohm load range just fine. I'd reccomend going with the Type R's and depending on if you want loud, boomy bass with very good low end go with a ported enclosure, or for tight bass go with a sealed enclosure
One concern i have for you though is your stock automobiles electrical capacity. Since your going to be running dual subs..each at 400watts RMS thats an 800watt load for your alternator to keep up with.
Stock American Automobiles come with <105amp alternators on average. It takes 50-60amperes to run stock electricals (IE. heater, Ac, Fan, Lights, etc.) that leaves you with 40-50amperes to play around with, without having to upgrade your electricals to support the new load.
In order to figure out the amperage load your new system will have, get the total wattage of your system, divided by the amplifiers efficiency factor, divided by the charging voltage (13.5V good average number). For this ill just use the RMS value for your as your RMS value is 800watts....800/.5 (Class AB amplifiers run at about 50% efficient) 800/.5 = 1600....1600/13.5= 118amperage load for this type of amplifier. For subwoofer applications we reccomend going with a class D mono amplifier. These run at about 90% efficient while still producing massive wattage.
Now tack on the 60amperes for your stock electricals on top of the 118amp load...BAM 178amp alternator you need. The whole electrical upgrade process including a battery will run you >$500 then tack on on wiring costs, pans out to be rather expensive
Im not trying to discourage you, just merely informing you of the possible problems you could run into with running a larger 2channel AB amplifier. If you can get a hold of a 800watt MONO amp that would help you out. 800/.9=888amperes. 888/13.5= 65.5amper load....65.5+60= 125amp alternator. With the MONO block amplifier you might get by with running a battery with >850CCA and upgrading your Alt-Bat, Bat-Ground, Engine-Chassis wires.
Hope this helps ya out.
-Jason
Relax_The_Mind on 10/18/2004 11:30:38
That amp is more than enough to push those subs.
In simple... get the dual 4 ohm models. Parallel the voice coils to 2 ohms and run them to the individual left and right channels. 2 dual 2ohm subs work best with a mono amp that is 2ohm stable.
Quote Victor
"{what u shud do is wire both the voice coils( of both the woofers ) in series that way u can get a load of 4 ohms per woofer.. and then wire the woofers in parallel or wire the voice coils in parallel and then the woofers in series.. that can get u a load of 2 ohms..}"
That sounds strange because the only way you could use 2 ohms on that amp is unbridged to one channel.
Quote Victor
"{wire the voice coil of one of the woofer in series and the other in parallel.. that will give u a load of 4 ohms for the series wired coils and 1 ohm for the parallel wired coils.. then wire the woofers in series to give u a total load of 5ohms.. at this load the amp will give something near 650-700 w rms( mono)}"
That would not work either as that would be giving one speaker 75% of the power and the other speaker 25%. Which would cause one of both speakers to blow . You must match the impedance of each speaker as power is dropped across a speaker according to its resistence. Yes it is strange.
vicflo
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