i recently purchased a used rockford fosgate woofer in a box with a motorola tweeter. it also came with an amp but it was no good. i emailed rockford fosgate to id the sub and they said"That is an 8" driver from a pre-fabricated enclosure.
It is a 4 ohm single voice coil driver with a 100 watt RMS rating." The previous amp was running two of these and was a 400 watt 2 channel. what numbers should i need to run this setup with just one of the speakers and tweeters? should i not just need something with 100 watt rms on each channel or since i have the motorola will i need a little more. also it would probably handle more power, correct? thanks and also any suggestions for a good amp under 100 dollars. thanks again

 

My suggestion would be a little two channel amp with anywhere between 35-50 watts per channel. as long as the amp is two ohm stable, and can be bridged mono, you'll be matching the rms rating on the sub. You might beable to find something like this for under a hundred, but i doubt it. remember with everything else in life, you get what you pay for!

 

i found a cheapie pyramid amp that is 120X2. this wouldnt be too much for the sub would it?

 

Unfortunatly with an amp like that your not going to get the tuning ability you would get with a little higher end amp. don't look to get a ton of bass out of that little 8 incher, no matter what amp you put to it.

 

Stay away from pyramid. Jensen makes a cheap line of amps that isn't too bad, you might check out EBAY for that too. I would go with a 150-200W amp, and you won't have any problems.

You can get plenty of bass out of 8 inch subs, I have 2 8'' Rockford Fosgates (different model than yours) in my truck and they hit really hard, most people think I have a lot bigger.

 

i dont need a ton of bass, just wanting a little more bass on top and enough to work the sub good.

 

I have a 300 watt max amp powering two 12" Eclipse subs, sounds unbelievable, bridged mono so puts out more than specified, KAC-716, do a search on E-bay for this amp model number, its a Kenwood, and will not cost you much!

 

Go to Wal_mart and get a cheap Pioneer, Small 2 Channel and Bridge it down to single channel....You really are not going to get much from that 8"...

 

You guys shouldnt be so biased about 8"s. My buddy has 3 audiobahn 8'"s that blow away 12"s. You just need to find out how much you are willing to invest (key term here) into the deal, before you start looking at features. If you are trying to stay under 125 dollars, do like above mentioned and check into Jensen for a quickie fix.

Garrett

 

it's all about matching! your motorola may need a cross over to be in tune with the frequency to optimise the sound from it. meaning that tweeters use high pass fileters to allow higher frequency not lower frquency (bass) because tweeters are designed for higher frequency. 8's work extremely well for tight area's depenind on the deep they have to pull from. Meaning the deep of the box that contain the speaker must be matched pretty close to push that bass from it. lots of jargin but basically remember a bass speaker is in box to push that air in the box to produce base . the speaker needs to match the correct box. "the prefabricated enclosure". As far as the amp goes it all depends on the wiring. Does it have a cross over to split the bass from the treble? if so then more power the better sound up an to the limit of the speaker. most speakers have a rms range instead of one hard number but for most bass woofers it's about 40 watts give or take meaning that if rms is 100 the range is 80 to 120watts. Any mono channel or bridgable amp sould work perfectly. as long as you meet the rms for the speaker. i like pyramid because they are cheap, but they break easily. i agree with getting a pioneer most back for the buck with great reliablity. Remember the more power the louder but just that louder not always clearer.
-bcareaga

 

If this is a typical "truck box", then that 8" is probably good to down to 50-60hz. It is not a subwoofer. Just want you to know. It is more like a midwoofer. What other speakers do you have? How effective this speaker would be depends a lot on the rest of your system. If you do not currently have much bass, then this 8" may add something to your system, but it will not be astounding. Especially with 100 watts RMS. If you do decide to use it, then disconnect the tweeter. It is designed to be used in a pair. An amp of the 2 channel variety capable of 100 watts RMS into 4 ohms when bridged would be suitable. A mono amp in the $100 range might be tough to find. WallyWorld probably has a Pioneer, Kenwood, or Lightning Audio that fits the bill.