Advice needed

[jmcinvale 10+ year member]

I am using a Rockford-Fosgate P400-4 amp to power four Infinity Kappa 62.7i speakers which are 2 ohms. I am looking to upgrade my speakers to these http://signature.crutchfield.com/s_091165KRC/Focal-K2-Power-165KRC.html?search=focal+car+audio&ssi=0

I am wondering how using 4 ohm speakers will affect my available power output.

I am also wondering why a lot of car speaker manufacturers use a 12 db/octave crossover on the tweeter and no crossover on the woofer. I've seen several speakers like that and IMHO there should be a 12 db/octave crossover on the woofers as well.

Click to read more...

 

[modskwod 10+ year member]

You would be halving the power to the speakers. It probably won't get as loud unless the focals are more efficient than your current speakers

 

[jmcinvale 10+ year member]

I thought so. I may try to install a 12 db/octave crossover on the Infinity woofers and see if that makes the speakers sound better. All I would do is get the same inductor and capacitor as used for the tweeters. The first schematic shows the speaker in stock configuration. The secont schematic shows the speaker with the 12 db/octave crossover on the woofer.

 

[fliptwister 10+ year member]

I'm surprised that gunz4me2 has not chimed in yet...

He does not believe that the Kappas really run at 2 ohm. Here is thread where I posed question about 2 ohm Infinity speakers:

http://www.caraudio.com/forum/showthread.php?t=434930

I was asking about the current gen of their speakers though. Are you sure your current speakers are really running at 2 ohm?

How many watts RMS is your amp running at? I think that RF has that documented on birth sheet that came with amp. While that Focal set is very nice I wonder if you will be running enough power to them to make them shine. Were you planning on going active or bridging channels?

 

[jmcinvale 10+ year member]

My amp can run 100 WPC into 2 ohms and it has four channels. I planned on running the Focals regular by just connecting them to the amp like my current speakers are connected.

I need to check and see what impedance the Infinity speakers really are.

I'm going to pull one of my crossovers today and see what capacitor and inductor it uses. I then will build a crossover for the woofer using those values provided the woofer and tweeter are the same impedance. That should give me better sound. I've always heard that it was bad to run a woofer in a multi way speaker system without the woofer going through a crossover.

EDIT: I did not pull the speaker today. Maybe I will get to it sometime tomorrow.

 

[jmcinvale 10+ year member]

I am wondering if I should just go and buy some midbass speakers, tweeters and then design a crossover.

 

[jmcinvale 10+ year member]

What I may do is go with the Focals. I must have the gain on my P400-4 amp set real low in ordeer to keep the speakers from being too loud at low volume settings on my head unit so I figure that I have enough extra gain to power 4 ohm speakers. I did notice that when I had the factory speakers connected to the amp they sounded almost as loud as my Infinity speakers do.

What bothers me is it appears like the Focals http://signature.crutchfield.com/S-jKTA9kmcfHS/s_091165KRC/Focal-K2-Power-165KRC.html?search=focal+car+audio&ssi=0 only have a crossover on the tweeter and not the woofer. Does anyone know of a good 6 1/2" - 6 3/4" speaker that has both a crossover on the woofer and the tweeter?

I basically don't want to buy something costing that much only to spend more money adding a crossover for the woofer when I can simply add a crossover for the woofer to my current speakers.

I want these speakers http://signature.crutchfield.com/s_091165KRX2/Focal-K2-Power-165KRX2.html?search=6+3%2f4%22+speakers&ssi=0 except they are a bit expensive for my liking and I would have to find a place to mount the tweeters so that I can make it to where I can return the car back to factory should I ever decide to sell it, but I will buy them if they are good.

According to Crutchfield those Focal speakers do not fit //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif What do you all think? Will they fit provided I find a place to mount the tweeters?