Hi all, and WOW! What an excellent forum. Sorry if my post looks newbie but, ahem, sorry. I have been piecing together a system for my little daily driver. I purchased this amp on auction http://community.webshots.com/photo/76043567/84444920QYkvmf and can't confirm the model. The amp is upside down but it all it says is Punchi on the label. I know it's a Rockford Fosgate 2 channel. It will pop any fuse under 30 amps. It has an rj45 connector for remote base control and a gain adjustment knob as well as an internal crossover. Knowing the exact specifications will surely help craft a complimentary sub setup, I hooked it up to a pir of 12" MTX Thunder 4k's but they tend to clip at high volume or reeeel deep base notes. Any input would be appreciated. Thanks Oh , running the amp on a crappy Sony explode mp3 player. 45 X 4 (for now)
Replies (4)
Relax_The_Mind on 08/11/2003 06:05:07
What does it say on the bottom ...nothing? Its almost impossible to tell what amp it is from the front several models of RF amps use the same size casing. judgeing from its visual size and bnlowing of anything below 30amps its pushing at least 500w . im guessing it may be the 125Wx2 possibly the 200Wx2 but im not sure. If you can measure it we can look it up by dimensions.
Most all RF Punch amps are 2ohm stereo stable. Not stable in 2ohm mono.
How did you hook up the speakers? looks as if its bridged and hopefully not hooked up 2ohm mono. That will cause it to clip at high levels and deep bass hits. RF amps have pretty rugged protection circuits.
So basically im also asking what ohm speakers do you have too and how do you have them wired.
RTM
ps someone help me on this
Swez on 08/11/2003 11:47:18
Cannot tell what version that amp is either... maybe an older Punch series 300?
If it is Rockford amp, it would clearly show the model number and the fuse holder should have a fuse rating. That can help us figure out how much power it has avaiable.
Also, the MTX subs mentioned... are the 4 or 8 ohm versions? Depending on which sub version you have here, there are different ways to wire them to this amp for safe performance.
On the magnets edge, there are some faint numbers stamped on the sub magnets that tell what these are (4 or 8 ) ohm subs. There is also a date code. Hard to see these details as they are usually in blue ink and in the side of the magnets. Have a look and let is know what you find. Then, we can help sort out your best wiring options.
If these are 2 @ 4 ohm subs (internally wired parallel) and you have the amp bridged (looks that way) you'd have a 2 ohm load to this amp and that will cause the amp to run very hot and eventually fry.
If these MTX subs are 8 ohms (good chance) and wired in in parallel, that's a 4 ohm load and fine for bridging the amp as noted.
Finally, if you system is distorting, probably a combination of HU settings and amp gains. Most HU's will begin to distort between 60-70% of max output, even less if using lots of bass EQ in the HU.
There is an faq in this site that helps explain how to tweak your subs. Have a look and follow the steps.
Swez
Popkorn on 08/11/2003 21:49:50
Thanks a lot guys. After downloading 15 or 20 pdf files, I finally found one that best describes what it is. http://www.rockfordfosgate.com/rftech/library/1999/3_Amplifiers/MAN2368C_Punch2ch_MAN.pdf
I took some measurments and it measures closest to the punch 250. The connections and features for the 250/360/500 are exactly the same. Dimention wise, it looks loke the 250.
And thanks for the tip on the sub. It actually has a sticker on it indicating a 2ohm load. The pdf manual says that's a no no for the amp. It does get pretty hot, wired as is. The subs are MTX's T4124A's 4ohm 200Wrms. They should be quite happy once I get them wired seperatly, one into each channel.
compvr15s on 08/12/2003 03:36:32
its probably a no no for 2 ohm mono, but as 2 ohm stero its ok. do you have one sub to one channel and the other sub to the other channel? if so thats fine but if you have them wired together and run the amp bridged thats probably why its getting hot. you should get the same power to each sub either way you wire it. and the seperate sub to seperate channel will cause less of a work load on the amp and make it run more stable. lol i just read the bottom of your post and answered my own question but i dont want to delete all my precious typing. good luck
Replies (4)
Relax_The_Mind on 08/11/2003 06:05:07
What does it say on the bottom ...nothing? Its almost impossible to tell what amp it is from the front several models of RF amps use the same size casing. judgeing from its visual size and bnlowing of anything below 30amps its pushing at least 500w . im guessing it may be the 125Wx2 possibly the 200Wx2 but im not sure. If you can measure it we can look it up by dimensions.
Most all RF Punch amps are 2ohm stereo stable. Not stable in 2ohm mono.
How did you hook up the speakers? looks as if its bridged and hopefully not hooked up 2ohm mono. That will cause it to clip at high levels and deep bass hits. RF amps have pretty rugged protection circuits.
So basically im also asking what ohm speakers do you have too and how do you have them wired.
RTM
ps someone help me on this
Swez on 08/11/2003 11:47:18
Cannot tell what version that amp is either... maybe an older Punch series 300?
If it is Rockford amp, it would clearly show the model number and the fuse holder should have a fuse rating. That can help us figure out how much power it has avaiable.
Also, the MTX subs mentioned... are the 4 or 8 ohm versions? Depending on which sub version you have here, there are different ways to wire them to this amp for safe performance.
On the magnets edge, there are some faint numbers stamped on the sub magnets that tell what these are (4 or 8 ) ohm subs. There is also a date code. Hard to see these details as they are usually in blue ink and in the side of the magnets. Have a look and let is know what you find. Then, we can help sort out your best wiring options.
If these are 2 @ 4 ohm subs (internally wired parallel) and you have the amp bridged (looks that way) you'd have a 2 ohm load to this amp and that will cause the amp to run very hot and eventually fry.
If these MTX subs are 8 ohms (good chance) and wired in in parallel, that's a 4 ohm load and fine for bridging the amp as noted.
Finally, if you system is distorting, probably a combination of HU settings and amp gains. Most HU's will begin to distort between 60-70% of max output, even less if using lots of bass EQ in the HU.
There is an faq in this site that helps explain how to tweak your subs. Have a look and follow the steps.
Swez
Popkorn on 08/11/2003 21:49:50
Thanks a lot guys. After downloading 15 or 20 pdf files, I finally found one that best describes what it is. http://www.rockfordfosgate.com/rftech/library/1999/3_Amplifiers/MAN2368C_Punch2ch_MAN.pdf
I took some measurments and it measures closest to the punch 250. The connections and features for the 250/360/500 are exactly the same. Dimention wise, it looks loke the 250.
And thanks for the tip on the sub. It actually has a sticker on it indicating a 2ohm load. The pdf manual says that's a no no for the amp. It does get pretty hot, wired as is. The subs are MTX's T4124A's 4ohm 200Wrms. They should be quite happy once I get them wired seperatly, one into each channel.
compvr15s on 08/12/2003 03:36:32
its probably a no no for 2 ohm mono, but as 2 ohm stero its ok. do you have one sub to one channel and the other sub to the other channel? if so thats fine but if you have them wired together and run the amp bridged thats probably why its getting hot. you should get the same power to each sub either way you wire it. and the seperate sub to seperate channel will cause less of a work load on the amp and make it run more stable. lol i just read the bottom of your post and answered my own question but i dont want to delete all my precious typing. good luck
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