This may seem obvious but I just finished installing a new system and I was wondering how much difference a better amp would have make on the overall SQ.

I installed a Basslink and Infinity Kappa components 6.5 driven by a Rockford Fosgate 401S 2 channel amp all connected to a new HU. The system sounds much louder than stock but the sound quality was not a huge leap. At one point, I was considering a JL 300/2 amp but decided on the RF 401S after reading several posts saying that an amp does not improve the HU sound, it only amplifies it and noticing that specs are similar.

Without going to the extremes in price, is there really a difference in SQ between an RF401S and a JL 300/2 or similarly priced amp?

The specs between these two amp and others I read seem to be almost identical. Is it a matter of listening to tell the difference in SQ or is there a particular spec that would give you a hint as to what amp give better SQ?

Thanks.

Mike

 

well if you think about it..... your new system gets alot louder but doesnt suond 100x better right? well before im sure you never turned up the stock system up as loud as you do now, if you did you SHOULD notice a huge difference due to distortion coming on alot earlier than your system now. also what h/u do you have? i think you need to do some tweaking to it. always keep your bass at around -1 and treble to your liking.

 

bass at -1? I always shoot to get the gains set with the levels all at 0. But it is true that most people associate a loud system as being a good sounding system. Therefore when they get more power and speakers that can handle the power they are not happy.

 

ive heard 0 or -1. but i figured maybe hes getting too much distortion from hi mid bass driver so i put -1.

 

Thanks everyone,

My HU is not the greatest unit in the world but it has some nice features and decent specs (JVC-KDS9250)

I am really not getting much distortion, on the contrary, the HU has a range of 0-50 and 22-23 is the highest my ears can confortably take. The stock Clarion HU/speakers combo could not be cranked up anywhere as high as my new HU/RF401S/6.05CS combo but at levels below distortion it sounded very nice. Somehow I've never been able to get the quality of sound that I get from my home stereo in my car. The quality of music from a middle of the road home stereo at either low or high volumes is better than the quality of music in my car (2-3x as expensive)

My question was related to the difference an amp would make on the quality of sound coming from the HU. Is there a noticiable difference between a RF 401S, an Audiobahn 2002T, a JL 300/2 or similarly priced amp or would they provide just about the same SQ? Does an amp add anything to the SQ besides making the sound louder?

Mike

 

Check in your crossovers for your Infinity Kappa Components. There is a jumper setting in them for a flat setting and an Infinity setting called custom contour. Mine came jumpered set at the custom contour setting even though the manual says that they are set to the flat as a default. The Infinity custom contour ads way too much bass, cuts off the mids and turns up the high freqs which sounded like "****e" to me. I set the jumpers to flat and have been happy ever since. BTW I am using the stock 2K2 non-bose head with a cheap Sony explode 60w rms X4 amp using speaker level inputs. I have Kappa 6.5" components up front and kappa 5.25's coaxs in the rear. I also have a Infinity 10" reference subwoofer. People are really surprised how clear and loud my system sounds. Plus it looks stock so no one will want to steal it.

 

This makes me wonder how bad the stock HU really is in terms of SQ. I realize that it does not have a lot of features/RCA outputs but SQ-wise it wasn't bad when compared to other $300-400 HU I have listened to.

I am assuming that nobody knows where to get the specs for it.

Why did you decide to hookup your rear to the amp rather than leaving them connected to the HU? I bought a 2 channel amp thinking that the rears could easily be driven off the HU for rear fill. Do you find yourself fading to the front to get a good soundstage or having the same amount of power going to both fronts and rears gives you good results.

Mike
P.S. My kappas came setup as contour by default as well. I started to wonder whether the manual was wrong, the speakers used or the crossover mislabeled. I personally could not tell the difference in output when using one setting or the other. Nonetheless, I switched to the flat position.

 

When I installed my system I originally didn't have my sub woofer installed. My rear infinity Kappa's needed a decent amount of RMS power to sound good so I used a four channel amp and fed all four door speakers from the amp. When they were connected to the amp's rear channel they sounded great and since the front and rear speakers were on different channels on the amp I was able to set their gains/bass boost etc seperately plus use the fader on the stock head unit. Now that I have a sub in the trunk I bridged the amps rear channel to the sub and ran my rear speakers in parrallel to the fronts from the amp. I ran the rears off the head unit once just to see how they would sound and didn't like it so I left them connected amps front channel with the front speakers. With this setup my stock headunit's fader fades between the 4 cabin speakers and the subwoofer in the trunk which is great when you want to turn down the volume of the sub during certain songs.
I always read people in here saying things that amping your rear speakers is a waste, it will ruin your soundstage, it's not what the competition folks do blah blah blah but I tried it anyway. I feel that with the crappy location of the rear speakers in the lower part of the door makes it almost impossible to mess up your soundstage. Now I have equal power to the front and rear rear speakers and got a nice rear fill, plus my back seat passengers get a better sound.

 

Sound that comes from behind your head without a delay is not proper sound. There is a right way and an infinite number of wrong ways. Rear speakers without delay is wrong. Amped rear speakers is wrong. Amped rear speakers without the ability to fade is wrong. Rear speakers not properly placed for correct soundstage placement is wrong. When you start listening to musical CD's on your stereo you might understand. You will be much better off with the factory fader and no amp for the rear speakers. If you can not hear your rear speakers with them getting the same power as the front speakers in the stock location you need to go to an ear doctor.

 

"The quality of music from a middle of the road home stereo at either low or high volumes is better than the quality of music in my car (2-3x as expensive)" welcome to car audio

Honestly though, you won't really hear a difference between those amps. Your weak link right now is the HU, IMO. JVC has nice features and is far from being a POS, but it is not a great performer in SQ. I know that's not what you want to hear, sorry. But RFs are decent amps and Infinitys are decent speakers, adding even more power than what you have now will not solve your problem.

You could try turning down the gains on the amp though. You want the HU to do as much amplification as you can get. For example, you said 22 is ear peircing - if you can get it up to more like 40 is ear peircing, then you signal could be clearer throughout the range. So that would be my first recommendation is the gain (plus it's a free tweak). Next is HU replacement, which is far from free, lol.

 

Thanks,

I will try playing with the gain.

Any recommendation on a good HU? That is what I was afraid of.

Mike

 

alpine, eclipse, pioneer.

 

"Does an amp add anything to the SQ besides making the sound louder?"

- In a word, no! At least not in a perfect world. If an amp adds anything it is not doing it's job. And nobody on this planet has ever scientifically heard a difference between amps with all other conditions being equal.

 

yeah Kenwood, Pioneer, and Alpine are my favorite of headunits in order..I love the exceptional clarity from Kenwood units (although it does no good without some decent speakers), but STAY AWAY from the 3D MASK units..they have a tendency to self destruct and require a new faceplate when the faceplate control wires get pinched..Pioneer units put out a higher preamp voltage, which usually means you get a cleaner signal going to your amp..I'm not REALLY experienced with Alpine, but the ones I've heard have sounded pretty good..I've never heard an eclipse unit, so I can't comment on them..

 

Alpine and Eclipse are my recommendations. Pioneer is a good one, too, but stay away from their lower end stuff.

 

I had Pioneer's BOTTOM end CD player, and it sounded fine..it was a DEH-14..My new Kenwood (KDC-MPV622) is much CLEANER sounding, but it doesn't sound as good if you use a separate amp for your midrange speakers and just use the RCA outputs (lower output voltage=higher chance of interferance and weaker signal getting to amp)..

Ok, I'm going to hijack this thread..I'm going to take one of my old amps (2 channels are fried on a 4 channel amp), and see if I can bridge it down to be 0.5 ohm stable..anyone here ever tried it? its normally 2 ohm stable in stereo mode..