I have an 04 xtype with premium nav. My passenger from speaker stop working so i bought a pair of alpine Spr -50c the specs are
100w Rms
impedance 4 (3.3dcr ohms)
freq response 70hz-to 29khz

I noticed the front factory alpines wasnt using a crossover and the tweeter was a clipon....to make a long story short, I used the crossover that came with the set that i bought.....But after its all done i noticed that the rear (still factory) is noticeably louder....How can this be? is it because i used the crossover??? or should i have adjusted it? it has 4 settings 0db -2db -4db and -6db. i left it on the default which is 0db.

should i have changed the jumper. if i do will it make the mid range speaker louder......

I have a severe lack of knowledge when it comes to sound systems...and the terminology i just know how to hook up wires. I bought it because it came up as a recommendation on crutchfield.com

any advise will be helpful thanks

 

jagkid, odds are, what you are hearing is an effect of a "low sensitivity" speaker. What I mean by this is that every speaker has a rating that most manufacturers call "sensitivity" (some call it SPL). But, this is a measure of how much sound the speaker makes with a given electrical signal applied to the speaker when measured at a given distance (normally measured at 1 W RMS at 1 meter). So, you can have what appear to be 2 identical speakers, but they can have completely different sensitivities (due to the construction of the speaker).

To put this into something that you can look at and possibly wrap your head around. If you take 2 speakers, one that has a sensitivity rating of 91 and a second one that is rated at 88 (all other specs being the same), the 91 speaker is going to sound twice as loud as the 88 speaker (this is due to sound being measured using a natural log, if you want to know more, let me know).

If you have more questions, let me know. I do car stereo install on the side and will help you through whatever you may have questions about.

 

thanks for the speedy reply...yes that makes sense to me. I went and looked up the SPl for these and they are 87dB (1W/1m).....would you have to know the spec of the factory apline speakers

 

jagkid, no, I do not know the sensitivity of the factory speakers. Based on what you are saying, I would venture to guess that they are either 89 or 90 dB speakers. But, that is just a logical guess.