a little help needed from you audio experts , as I know nothing about it... I was going to purchase the new Fosgate PBR300X2 amp for my roadglide , and I noticed it is rated at 150 watts per channel @ 2 ohms , but only 100Watts at 4 ohms... now I notice that all the aftermarket speakers like Focal 165s are 4 ohms... so will I be better to try and find some 2 ohm speakers or will 100 watts x 2 speakers be enough ?? and will there be a problem wiring up this amp to my stock head unit ?? Like I said , I am not an audio expert so hoping for good advice on here ...thanks

 

I would buy the 300x4 just because your 4ohm speaker options are better. somewhat there are alot of good 2 ohm speakers out there I just can only name Infinity.

 

Well I am not sure what all the terminology means , but if I am thinking right , the 300x4 only has 75 watts per channel , instead of the 150 or 100 that the 300x2 has ... and since I will only ever have the 2 speakers , wouldnt I be shooting myself in the foot with the lesser power of the 300X4 ????

 

I guess if you can find a speaker that can handle 150watts RMS at 2 ohms that would be the way to go. since your not "planning" lol on going for a four speaker setup.

 

The 2 channel RF will match up perfect to a pair of Focals. You will get roughly 100w per speaker and that is plenty. You can wire it into the factory HD stereo using the speaker line inputs on the RF amp. What that basically means is you take the speaker wire that runs to the stock speakers and use that as your input to the new amp and then you run new speaker wire out of the amp to the speakers. The 2 channel one is a good choice and if by some chance you added lowers with two more speakers you could run it at 2ohms and be safe still with plenty of power. Hope that helped

 

thanks Police tech , that is what I was looking for ... now what speakers do you like , that sound great without breaking the bank ? (like around $200 or less per pair ) gimme some options ... I have followed your audio posts and you seem to have the skinny on what options are out there .When I look up 6.5 speakers there are so many , including so many different part numbers from the same company .. like Polk , Focal, infinity etc ...and who has the adapters to make 6 1/2s fit my Roadglide ???.I dont like the looks of lowers ,and I use my saddlebags and tourpak for luggage so I only anticipate ever having the 2 speakers so I want a decent set ..... I have had Hogtunes speakers on a couple bikes in the past and thats just not what I'm looking for this time ..If you know what I mean...

 

I thought that the Rockford 300x4 should only run speakers that are 4 ohm. Running a lower ohm speaker would make the amp work harder and overheat. I would buy the RF amp and use a set of 4 ohm speaker. Then in the future you will have the extra channels.

 

Blockzilla, I'm in the same boat as you. Don't know sh*t about stereo systems / speakers and I want to upgrade my 2012 RGC. Going the same route in keeping the HK head unit , but want a better set of speakers and will upgrade to an amp someday. I found a FG pbr300x4 for $199 : http://www.phatperformanceparts.com/...p/pbr300x4.htm

Now what speakers would go with this ( Max. $200 ). Is 4 ohm better than 2 ohm, why the concern over the ohms???

Speaker adapters: http://www.arcaudio.com/motorcycle.asp , http://www.ebay.com/itm/320818654643...WAX:IT&vxp=mtr

Thanks for the help, Chris

 

The Rockford amp is a 4 ohm amp it's not stable running 2 ohm speakers. You will overheat the amp and shorten the life of the amp. The ARC 125.2 amp will run at 2 and 4 ohms with no problems. Both amps are great. For the money the Rockford is the bigger bang for the buck.

 

This is from the Focal web site.

The most common causes of voice-coil problems

Amplifier far too powerful
Contrary to another popular belief, it is rare for a powerful amplifier to damage a loudspeaker. Even at a high level, the signal remains clean and with very little distortion. For example, a great number of professionals have seen the power indicators on large amplifiers reach 300 Watts in a short burst, without causing any damage, even though the speaker used was only a maximum of 90 or 100 Watts. If the amplifier is really too powerful (double or triple the power of the loudspeaker), there’s a risk that requires reasonable control of the sound level. In this precise case, the device may lead to the destruction of the bass speakers.


Amplifier not very powerful or under-scaled
A common and unfortunately dangerous situation. As a precautionary measure or unfamiliarity with reality, many users choose an amplifier which is too weak. At high regime it will clip and distort or fail to send "square signals" or, through power supply destabilisation, it will supply direct current to the loudspeaker, which will be fatal for it. During clipping, a 40 Watt amplifier can reach 100 or 120 Watts distorted over 1 millisecond. This problem is often encountered on 40 or 50 Watt amplifiers from bottom of the range manufacturing or to prevent listening at high level. In this other case, the device may lead to the destruction of the treble speakers. If the power gap is large (amplifier less than 30 Watts for an 80 Watt loudspeaker for example), the bass power supply will become difficult and may damage the loudspeaker.

Use error

• Excessive use of sound volume: the more powerful the surround system and more excessive the volume, the greater the difficulty for the amplifier to relay a quality signal. If at moderate power (maximum one third of volume), the power and musicality achieved are not at all qualitative, increasing the volume may only make matters worse (appearance of distortions). It is necessary to have amplification that complies with the requirements of the loudspeaker.
• Excessive use of the bass and treble correctors: although reasonable correction can improve listening, setting the correctors to maximum or thereabouts will increase the power emitted in the registers concerned approximately three times or more. Example: without a corrector, at an average level of approximately 30 Watts (which is already loud), for a 2-speaker kit, the sound repartition will be approximately 7 Watts for the tweeter (treble) and 23 Watts for the loudspeaker. If the bass are turned up as high as they will go, they will receive (for the same volume setting), approximately 80 Watts instead of 23! In this case, it would be necessary for the amplifier used to be capable of delivering this power without distortion.
• Immoderate use of an equaliser: the main, true value of an equaliser is to correct any faults caused by the passenger compartment. Unfortunately, it is rarely used in this way and tends to be used as a corrector to amplify bass and treble with no reference to reality. In this respect, it is not rare for certain buttons on equalisers to be turned up to +12 decibels - the equivalent of multiplying the power delivered at this frequency by 16. If we take the example of a woofer receiving 27 Watts, correcting by 12dB corresponds to a request for: 27 W x 16 = 432 Watts! As many amplifiers are not capable of delivering such power levels without clipping, this generates a considerable risk for the speaker.