Question about new subs but now less audio
11-13-2005, 01:40 PM
#1
0 Watt CAFz'r
Thread Starter
Join Date: Oct 2005
Posts: 35
I have just replaced 2 of my 12inch subs with another pair of SAME RATED subs and I am getting dramtically LESS AUDIO. What's this all about?
I do have a basic system ~ here it is! [img]tongue.gif[/img] Perhaps someone could shed some light on this!
Amplifier:
Pioneer GM-X802 (7 years old)
2CH 100W x 2 @ 4 ohms RMS
2CH 150W x 2 @ 2 ohms RMS ~ (amp is 2ohm stable)
Original subs x2: (7 years old)
Rock Fos RFP-1812 12inch 8ohm SVC 200 RMS/400 MAX
New replacement subs x2: (new)
Rock Fos P212S4 12inch 4ohm SVC 200 RMS/400 MAX
I have kept the wiring the same in parallel after installing the NEW subs. I thought for sure using 2x 4ohm subs in parallel (2ohm load) would be louder/powerful than my original setup with 2x 8ohm subs (4ohm load).
BUT THESE NEW SUBS ARE SO QUIET.
Any ideas???
My guess is these 2 new subs are "under rated" and I need a more powerful amp. Perhaps 300 RMS to each sub?
Any suggestions appreciated. [img]graemlins/headbang.gif[/img]
[ November 13, 2005, 03:01 PM: Message edited by: peemoeller ]
I do have a basic system ~ here it is! [img]tongue.gif[/img] Perhaps someone could shed some light on this!
Amplifier:
Pioneer GM-X802 (7 years old)
2CH 100W x 2 @ 4 ohms RMS
2CH 150W x 2 @ 2 ohms RMS ~ (amp is 2ohm stable)
Original subs x2: (7 years old)
Rock Fos RFP-1812 12inch 8ohm SVC 200 RMS/400 MAX
New replacement subs x2: (new)
Rock Fos P212S4 12inch 4ohm SVC 200 RMS/400 MAX
I have kept the wiring the same in parallel after installing the NEW subs. I thought for sure using 2x 4ohm subs in parallel (2ohm load) would be louder/powerful than my original setup with 2x 8ohm subs (4ohm load).
BUT THESE NEW SUBS ARE SO QUIET.
Any ideas???
My guess is these 2 new subs are "under rated" and I need a more powerful amp. Perhaps 300 RMS to each sub?
Any suggestions appreciated. [img]graemlins/headbang.gif[/img]
[ November 13, 2005, 03:01 PM: Message edited by: peemoeller ]
11-13-2005, 01:46 PM
#2
well your amp should have a 4ohm load when bridged not 2ohm... you were probably better off with 2 8ohm subs... you may be running you amp into premature distortion now....
also, your old subs may have been worked in nicely meaning low Q -more low end and louder but less accuracy....
maybe try a different box for the new subs and more power from a 2ohm stable amp couldn't hurt...
also, your old subs may have been worked in nicely meaning low Q -more low end and louder but less accuracy....
maybe try a different box for the new subs and more power from a 2ohm stable amp couldn't hurt...
11-13-2005, 01:51 PM
#3
500 Watt CAFz'r
Join Date: May 2004
Posts: 597
The GM-X802 was not 2 ohm mono stable so as Haunz said, this may be your problem as the amplifier is having trouble with the load you are providing.
Also, it will take some time for the suspension of the subwoofers to work in & loosen up so they should get a little louder after a couple weeks.
Before you go out & buy a new amplifier, try wiring the subwoofers in stereo & see how it works. Might be a quick & easy fix?!
Also, it will take some time for the suspension of the subwoofers to work in & loosen up so they should get a little louder after a couple weeks.
Before you go out & buy a new amplifier, try wiring the subwoofers in stereo & see how it works. Might be a quick & easy fix?!
11-13-2005, 03:41 PM
#7
Guest
Posts: n/a
basically you amp "see" 1/2 the total impedance per channel in bridged mode so a 4ohm mono load is = to 2 ohms per channel
so now 2ohm mono load like you have = 1 ohm per channel .......not good stuff for that poor amp
so ya as suggest run one sub per channel and try that, should be better
so now 2ohm mono load like you have = 1 ohm per channel .......not good stuff for that poor amp
so ya as suggest run one sub per channel and try that, should be better
11-13-2005, 08:26 PM
#9
0 Watt CAFz'r
Thread Starter
Join Date: Oct 2005
Posts: 35
So just to clarify...
when I was using the original 2x 8ohm subs and had them wired parallel and hooked the 2 wires up bridged in mono on my little amp (using POS from one channel and NEG from the other channel), the amp load was 2ohm ~ right?
and if the above is true, when I bought the same new 2x 4 ohm subs using the same connection, my little amp would see a 1 ohm load ~ right? not good.
Thus my new scenario, if I connected this:
Pioneer GM-D510M 1000 Watt Mono Class D Power Amp
Peak Music Power 1000 Watts
Number of Channels 1
Load Impedance Capability 2 ~ 8 Ohm (Mono)
Continuous Power (4 ohm) 300W x 1
Continuous Power (2 ohm) 600W x 1
Continuous Power Bridged (4 ohm) N/A
my 2x new 4ohm subs in parrallel like above scenerio would give the amp a 2ohm load and with my old 2x 8ohm subs a 4 ohm load ~ right?
well well well, I am really into it now! ha ha.
when I was using the original 2x 8ohm subs and had them wired parallel and hooked the 2 wires up bridged in mono on my little amp (using POS from one channel and NEG from the other channel), the amp load was 2ohm ~ right?
and if the above is true, when I bought the same new 2x 4 ohm subs using the same connection, my little amp would see a 1 ohm load ~ right? not good.
Thus my new scenario, if I connected this:
Pioneer GM-D510M 1000 Watt Mono Class D Power Amp
Peak Music Power 1000 Watts
Number of Channels 1
Load Impedance Capability 2 ~ 8 Ohm (Mono)
Continuous Power (4 ohm) 300W x 1
Continuous Power (2 ohm) 600W x 1
Continuous Power Bridged (4 ohm) N/A
my 2x new 4ohm subs in parrallel like above scenerio would give the amp a 2ohm load and with my old 2x 8ohm subs a 4 ohm load ~ right?
well well well, I am really into it now! ha ha.
11-13-2005, 08:54 PM
#10
500 Watt CAFz'r
Join Date: May 2004
Posts: 597
Close, but not exactly.
You're original setup sounds like it was running at 4 ohms mono (two 8 ohm subs wired in parallel). By just changing the subs you have now created a 2 ohm mono load (two 4 ohm subs wired in parallel).
If you're looking to upgrade you're amp to the GM-D510M that's an awesome choice! You will achieve the full 600 watts RMS it's capable of using the subs & wiring you have already installed. Have fun!
You're original setup sounds like it was running at 4 ohms mono (two 8 ohm subs wired in parallel). By just changing the subs you have now created a 2 ohm mono load (two 4 ohm subs wired in parallel).
If you're looking to upgrade you're amp to the GM-D510M that's an awesome choice! You will achieve the full 600 watts RMS it's capable of using the subs & wiring you have already installed. Have fun!
