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Old 08-13-2009, 06:32 AM   #1
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Question re amp and speakers

Darn, I am clueless when it comes to sound systems....

I am thinking of buying this amp:
Infinity Kappa Five

It outputs 4 channels of 75 watts at 2 ohms and 1 channel of 300 watts at 2 ohms.

Questions:
1a) I guess I'll split the one woofer output and drive it to the door speakers. Right?
1b) Do I need speakers or just woofers for the doors?

2) This thing has on-board variable electronic crossovers. That means that I don't need crossovers for the speakers (especially for the woofers?)

I was thinking of buying infinity kappa speakers (that have 2 ohms impedance) but I still don't know what to get for the door speakers (and one of them must be blown or something, because it sounds awful)

Excuse my ignorance and, please, guide me through this...

George

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Old 08-13-2009, 12:18 PM   #2
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Quote:
Originally Posted by gstoli
Darn, I am clueless when it comes to sound systems....

I am thinking of buying this amp:
Infinity Kappa Five

It outputs 4 channels of 75 watts at 2 ohms and 1 channel of 300 watts at 2 ohms.
Questions:
1a) I guess I'll split the one woofer output and drive it to the door speakers. Right?
1b) Do I need speakers or just woofers for the doors?
2) This thing has on-board variable electronic crossovers. That means that I don't need crossovers for the speakers (especially for the woofers?)
I was thinking of buying infinity kappa speakers (that have 2 ohms impedance) but I still don't know what to get for the door speakers (and one of them must be blown or something, because it sounds awful)
Excuse my ignorance and, please, guide me through this...
George


Most of your post is beyond my paygrade, but I did get Kappas 4" front and 4x6 rears. They are 2ohms and sound fantastic. The fronts took a little effort to put them in the existing housing, but the backs are giving me a headache. I am leaving the doors alone for now. You can always go to cruchfield and get some free pre buying support. Just a warning, they are high.

Oh, I am still using the stock amp as for a convertible it is plenty(so far). My Kappa speakers sound fantastic, with my new jvc hd50 head unit(best buy) $200ish installed.
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Last edited by mptoledo; 08-13-2009 at 12:27 PM.
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Old 08-13-2009, 12:57 PM   #3
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I think it's a great multi channel amp. Unfortunately... you are losing performance (power) for form factor. Why not look into a good 4 channel amp pushing 150 watts @ 2 ohms and a good 3-600 watt monoblock amp fo the subs?

Have you looked into Hifonics? They make excellent car amplifiers and the price is right. Check out the Zeus series. You could easily buy 2 amps for the same price as your paying for that one underpowered Infinity.

http://www.sonicelectronix.com/item_17652_Hifonics+ZXi+6410.html
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Old 08-13-2009, 03:00 PM   #4
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I just got back from Bestbuy and the install guy corrected me. The rears are running off the radio and the front and doors share a common ground and are running off the 4x40watt P amp. I was like no frickin way. The rears are blowing away the fronts. But he was very adamant about it, so i didn't argue
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Old 08-13-2009, 03:07 PM   #5
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I HIGHLY recommend the Alpine PDX 5. It fits right where the cd changer would go. It is rated at 75x4 (although the one i have came with a rating of 114x4) and 300x1 (mine is 406x1)

Probably the most compact and powerful amp you can find
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Old 08-13-2009, 03:48 PM   #6
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Quote:
Originally Posted by mptoledo
I just got back from Bestbuy and the install guy corrected me. The rears are running off the radio and the front and doors share a common ground and are running off the 4x40watt P amp. I was like no frickin way. The rears are blowing away the fronts. But he was very adamant about it, so i didn't argue
That's correct
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Old 08-13-2009, 04:31 PM   #7
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TG2K is right about the PDX series...

and if you want the same technology in a smaller cheaper easier version
Alpine Head Unit Power Pack, Model KTP445. Just plugs into the newer alpine head units. For those with no amp amd want a DIY with no headaches seems like the way to go.
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Old 08-13-2009, 04:32 PM   #8
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Quote:
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That's correct

so does the P amp suck and the jvc just that much better?

Also, since the rears are the only thing hooked up to the jvc do they still get the 40 watts or do the get extra since nothing else is drawing power?
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Old 08-13-2009, 06:13 PM   #9
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mptoledo, have you used the same speakers for dash and rears?

I find it difficult to believe that the jvc headunit with its integrated amp is better than the p-amp... If that's the case why using an amp anyway???? And makes you wonder... was Porsche saving money by selling the cars with such a crappy sound system???

Back to my original post...

I have chosen this amp because of its small size and thinking that the 75 watts should be fine. I will check on your suggestions though.
But you did not answer any of my questions yet. And now I have one more

1a) I guess I'll split the one woofer output and drive it to the door speakers. Right?
1b) Do I need speakers or just woofers for the doors?

2a) Thie Infinity Kappa Five has on-board variable electronic crossovers. Is that common among other amps?
2b) Heaving on-board crossovers means that I don't need crossovers for the speakers (especially for the woofers?)
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Old 08-13-2009, 06:35 PM   #10
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Quote:
Originally Posted by gstoli
mptoledo, have you used the same speakers for dash and rears?

I find it difficult to believe that the jvc headunit with its integrated amp is better than the p-amp... If that's the case why using an amp anyway???? And makes you wonder... was Porsche saving money by selling the cars with such a crappy sound system???

Back to my original post...

I have chosen this amp because of its small size and thinking that the 75 watts should be fine. I will check on your suggestions though.
But you did not answer any of my questions yet. And now I have one more

1a) I guess I'll split the one woofer output and drive it to the door speakers. Right?
1b) Do I need speakers or just woofers for the doors?

2a) Thie Infinity Kappa Five has on-board variable electronic crossovers. Is that common among other amps?
2b) Heaving on-board crossovers means that I don't need crossovers for the speakers (especially for the woofers?)

No, different speakers.
dash= Infin Kappa 4"
rears(first try) Kappa 6x4, beautiful sound but i couldn't get them to fit
rears(2nd try) I am ordering 1 pair of Kappa 3 1/2"( I may go with 2 on each side down the road depending on how I like the sound.

I bought some 3 1/2 infinity reference series at Best buy today. They are 2/16 of an inch smaller than the kappas. Either will fit in the stock rear mounting brackets. I can fit 2 if so desired.

Re amp: Can't say for sure if the amp sucks. I have never wired a stereo. I will do some research this weekend after I read the amp/jvc wiring diagram. I can figure out just about anything given time and help.

Short of it, if what the best buy installer tells me is correct and the rears are wired to the jvc head unit(kd-hdr50= 50wats X 4ch). Stock amp=40x4ch, wich is 10w less per chan than radio, hence radio is making the rears sound louder and better. I may just bypass amp and see how it sounds with head unit alone, (this weekend after I study the diagram). Seeing I have all the harnesses, disabling the amp shouldn't be too hard(hopefully).

YOUR QUESTIONS.
1.) doors= subs, but share a common gound with dash speakers. This is beyond my pay grade, so far. It may need re-wiring the doors and the dash so be prepared. kind of why i am leaving them alone.

2.)Cant answer this one. The kappas I bought have crossovers on the wires.

I seriously doubt you need an amp but its up to you. I had my kappas 4" and 6x4" running on my jvc today @ 40 out of 50 volume, and it was loud (with the top down)!! Crytal clear but loud. I have klipsch ref series hooked to marantz seperates for my home theater/entertainmetn. I like my music loud, clean and clear!! I strive for perfect reproduction on a budget. My car is damn close to it.

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Last edited by mptoledo; 08-13-2009 at 06:39 PM.
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