Amp - Components Relation

Okay, after figuring out my Amplifier Settings I started on the changes this past weekend. After removing the seat, I made all the necessary adjustments. The stereo was sounding great, but I had one more thing to check.

I have Infinity Kappa Components in the front. They came with a separate crossover to divide frequencies to the mid and the tweeter. Within the crossover is a jumper that can be switched between two settings, flat or contour. The contour setting reduces the mid range and results in more percieved bass, or something like that.

I decided to test to see the difference, with the music playing I faded all of the sound to the front, to my suprise, the volume was so low coming out of the fronts, that it almost sounded like it wasn't working correctly. I checked both crossover settings, and the sound didn't change much. The only sounds coming from the mids were vocals, very quietly at that. The tweeters were putting out the expected frequencies, but not loudly, even though I had the volume at a decent level.

When I initially set the gains, I was listening to the entire system. I just assumed that because the fronts and rears were rated the same (RMS and frequencies), that the gains should be set the same. However, the volumes coming from the rears (3-way 6.5") was much greater than the fronts. Does it make sense that the gain on the fronts would have to be set 30% higher to get the same output as the rears, even with the same RMS ratings? And is that what I want to do?

I always thought component sets were meant to "scream", not whisper.

Does it make sense that the gain on the fronts would have to be set 30% higher to get the same output as the rears, even with the same RMS ratings? And is that what I want to do?

Yes.

If they were the exact same brand and model of speaker, I would worry. But if they're a different brand or model of speaker, then it's normal to get different amounts of volume out of them.

The RMS rating is not an "expected volume" rating. It's a "how much power can I put through this speaker before it distorts" rating. The volume is determined by different factors, such as speaker cone size for example. Some places quote a number called "efficiency" which is supposed to indicate how much of the amplifier energy is converted into sound waves. When comparing two similarly-sized speakers with similar specs, the one with the higher efficiency number will be louder.

Fronts and rears are both Infinity Kappas, 6.5". Fronts are components, rears are three-ways. It makes sense that the gains would be different, but it just seemed odd because the speakers were so similar (ratings wise).

I would think that the components could take more power anyway. I'll try that next.

Also remember that setting different crossover points for speakers will change the amount of energy going to them.

where are the mid components mounted? in the door next to your feet? if so, i can see why the rears sound louder. the sound in the mids get trapped in the leg area of the front seats, while the rears get to bounce off the rear windshield and fill up the rest of the back. and your tweeters if mounted earheight, fills the upper half of the front.

or it might be that the fronts are out of phase and are cancelling each other out. i'd check on that.

Yeah, and depending on where the rears are mounted, they might be using the trunk as a sealed enclosure, whereas door speakers don't really have an enclosure behind them at all.

Sorry, I have a regular cab Dodge Ram. Mids are in the doors, tweeters are in the dash. Rears are behind the seats in the side walls. No sealed enclosures.

The system sounded great until I realized how little was coming from the fronts. I'm talking shocking. When I faded to the front, I got down on the floorboard to listen to the mids, and it was barely audible. The tweeters sounded better, but the mids were definitely lacking.

With the gains at the same levels, I had to turn the volume on the Empeg up 8 dB higher to get approximately the same volume from the fronts as when I played solely the rears.

The rears also emitted much more bass. The rears also came with a crossover (a simpler one) to separate frequencies to the two tweeters and mid. The rears sound great, while the front mid seemed to only be playing highs.

Maybe you've accidentally got a high-pass crossover on your amp turned on?

I do have a high pass crossover on for the fronts and rears. I think it's set at 120Hz. Both are set the same. The sub is crossed at 200 Hz, which is what it is rated to.

Sorry. I meant that maybe it's set to only allow really high frequencies. You could try disabling it to see what happens, though.

Yeah I thought about disabling it as I wrote the last post. But if the crossovers were set the same, the speakers should still be receiving the same frequencies as the rears. Unless the problem lies in the component crossover. I'll try it, though. Could just be a faulty crossover knob on the amp for the front channels.

I had an amp under the front passenger seat once that had a button labeled "hi gain/lo gain". My (now ex) wife kept accidently pressing the button when she tried to stuff her purse under the seat when she used my car. Resulted in simliar problems with front/rear imbalance. (And, no, that's not why she's now an ex. We're still friends.)

-jk