Douglas93FD

About a year ago I installed a pair of 6.5" Rockford Fosgate Punch shallow mounts in the front, and a pair of RF Power 6x8s in the rear. The front RMS is 70 and the rear is 80 RMS. I am using a aftermarket head unit that is probably 50w x 4. The speakers get pretty loud nicely, but when turned up the bass comes out crackly and distorted.

I am wondering if it is the speakers that just can't handle a lot of bass, or is it that the radio is a POS and an amplifier would fix this and allow the speakers to handle more bass?

Thanks!

squalor

iTrader: (12)

Personally, I don't like back speakers, or as the car audio people call them, rear fill.
I have never seen a head unit that puts out 50x4 rms. Thay may claim 50W peak or max but at what distortion level. That crackly, distorted sound is your head unit hard clipping. Enough clipping can hurt your speakers.
If your Rockford Fosgate 6.5" were powered by a small amp (30W or better) you would be shocked at how good they sound. If your battery is in the bin install is pretty easy.

Douglas93FD

Good point about the radio and RMS, it isn't. I am going to invest in a small 4 channel amp. Rockford makes some small ones that should do the job. Thanks for the input. And no the battery is in the bay, no biggy.

squalor

iTrader: (12)

Will you be doing the install yourself ? If so, I also have a FD and could give some advice.

Douglas93FD

Yes, I will be doing the install myself. Doesn't seem to hard, besides, I am an avionics tech in the Navy. Any advice you would have would be great. I have never done an amp before, but I did put my own speakers in. I have found two amps that I could use, both will cost the same.

Either the PBR300x4
PUNCH Amplifiers - PBR300X4 - Rockford Fosgate®


or the P400-4
PUNCH Amplifiers - P400-4 - Rockford Fosgate®


I am thinking the PBR300x4 is the best choice just because of the size. It is very small. I want to do the install as close to the radio as possible. I think I can get it under the passenger side dash. However, I will not be doing this install for about 2 weeks. I have to finish putting on my SS brake lines and speedbleeders. I try not to order too much stuff, that way it doesn't lay around too long.

squalor

iTrader: (12)

I can see how the small one (300W) would be compelling. It's topology, BR is simular to Class T. It is small because of this and uses very little battery power, hence the 10awg power wire. The knock on it is the class T, like class D does not produce treble as well. Often, there are artifacts and coloration. Class AB like the Punch 400 usually sound better, cleaner.
If you do get the 300, do not use the speaker wire input/current sensing remote turn on. Use the RCA inputs and remote turn on wire from the HU to amp instead. You'll need a amp install kit. Nutin fancy, a Scosche kit from Wal-mart will do but use good RCAs like the Fosgate set. Mount the fuse as close to the battery as possible. Use the gromet in the kit to pass thru the firewall, close to the A/C condensate drain and route the power wire well away from the RCAs or speaker wires. Amp ground is important. Remove paint where you set your ground lug, use the same gauge wire and seal the connection to chassis with thick paint or other sealer you trust. At your level, tie the amps speaker wires into the speaker wires from your dash harness (what your using now). Running new speaker wire is a PITA if your trying to use the un-used pins in the FD door connector and you may want to save these for keyless entry.
Once everything is hooked up but before the amp is fastened down (you don't want a sliding amp in a car like yours) you need to set Gain. Many ways to do this, Google is your friend. Here's how I do it. Get a CD with Bass heavy music in the HU. Turn the gain all the way down. Turn the amp all the way up. Slowly turn the gain up until you hear distortion and clipping. Then turn the volume down to 90%. If the clipping is gone, Bob's yur uncle. If not, dial back the GAIN some more until sound is clean. Set it and forget it, one time deal.
Douglas93FD, don't take everything i've said as gospel. Many people on here know more about this stuff than me. The job can be done much cheaper or much more expensive. Your car, your call.

DreamInRotary

iTrader: (49)

Well squalor, you did a pretty spot on job as far as im concerned. Nice explanation with plenty of detail.

I'm looking at doing the same thing in my fb since my new Kenwood speakers aren't putting out enough for me.

Douglas93FD

Thanks for the info. I know that the P400 will give me the better quality, but its all going to come down to "Will it fit?". In the next day or so I am going to go look at the car and see where I can safely mount the amp, and which will fit best. If I can nicely fit the P400, then great. If not, then I will go with the PBR300.

After I do the amp for the speakers, I am going to roll into my next project of making a sub enclosure for the back. But that will be at a later date.

squalor

iTrader: (12)

... a sub enclosure ?
With a 4 channel amp you might consider using a crossover and feeding your back 6x8 only bass from 100hz down and let them be your subs. If, after hearing your speakers the way they were meant to be heard - amp'd, you may decide you dont need a sub. If you still want one keep it light and low. This is a FD were talking about and you don't want to lose any performance. IF you can do without a spare tire you may consider capping the tire well with 1/2" MDF and use a 8" sub (not ported).

Douglas93FD

That is why I am putting the amp in for the speakers first, might not even need the enclosure. As far as the spare tire, that's a must keep for me. I don't like to compromise. Would the P400 give me the ability to do what you described above? Also, wouldn't that have beat the purpose of the 6x8 being full range?

squalor

iTrader: (12)

Here's my FD.
Currently, I have Boston Rally co-ax in the doors and back. Steel frame speakers, a name brand but value design. I have a Alpine 7998 HU and no amp. I have big plans, have amp and better speakers but short on time. I work at a resort and summer is a busy time for me.
I fade all sound to the door speakers. Most car audio fans do this too. When you go to a concert do you stand with your back to the band ? With only the door speakers, sound is centered above the dash. Any left or right panning of the music is directional and defined. You can almost pick out where the players location is. They call this staging or front stage. When you fade in the back speakers it pulls the stage back and puts you in the middle of it. Directionality is somewhat lost. That's why a really good car audio car only has front speakers and a sub. Really good front speakers like Seas Lotus. Really good amps like Arc Audio. They start with a quiet car like a Lexus, never a FD. That's the challenge for us; to have good sound and keep the things that make a FD a FD.