Amplifying aftermarket speakers

xinsungx · 12-31-2006, 03:00 PM

So I will be ordering infinity reference speakers in the next few days...6.5 components for the front and 5.25 coaxials for the back. I'm not changing the headunit so I will need to get an amp but probably won't be able to get one until the summertime. Do you think I'll be fine till then? I don't want to mess up my speakers...

...also...the amplifier I have my eye on for now is the infinity reference 7451a 4 channel amplifier:

http://www.crutchfield.com/S-qzsmd8w...20&I=108R7541A

...i found a good price for them for around 160 shipped.

Would you suggest anything else other than these? (I would like it to be no more than 160)

...thanks in advance..:)

***Devin*** · 12-31-2006, 03:28 PM

I wouldn't run aftermarket speakers off the stock system without knowing the specs. The speakers would most likely be highly underpowered, damaging the speakers.

That amplifier has decent power output capabilities for what you're doing, but I personally don't like the noise and distortion ratings. Harman pro products are damn good, but they're mobile lines are questionable, IMO.

audiophile · 12-31-2006, 04:32 PM

Quote:

Originally Posted by xinsungx

So I will be ordering infinity reference speakers in the next few days...6.5 components for the front and 5.25 coaxials for the back. I'm not changing the headunit so I will need to get an amp but probably won't be able to get one until the summertime. Do you think I'll be fine till then? I don't want to mess up my speakers...

...also...the amplifier I have my eye on for now is the infinity reference 7451a 4 channel amplifier:

http://www.crutchfield.com/S-qzsmd8w...20&I=108R7541A

...i found a good price for them for around 160 shipped.

Would you suggest anything else other than these? (I would like it to be no more than 160)

...thanks in advance..:)

Don't do that. Don't amplify high-frequency output speakers (Anything non-subwoofer) without replacing the headunit. It will sound like crap.

xinsungx · 12-31-2006, 05:05 PM

ok...so i guess i will have to hold off on the purchase of my speakers then..haha...so now i need some help on an amplifier...Devin..thanks for your suggestions ..i'll keep that in mind....ne more suggestions on a decent amplifier for the suggested price? If its around 100 i might be able to go ahead and purchase it right now...but i doubt that there are any good amplifiers for that price...right? Please keep in mind i'm only doing it so i don't ruin my speakers so i dont need ne thing fancy :)

***Devin*** · 12-31-2006, 06:30 PM

Not any I know of with power ratings comparable to that of the Infinity. I don't want to make any generalizations but from what I've seen I like the specs of JL, Kenwood, and even Phoenix Gold have good ratings. I don't know how much power you're looking for. So I guess the question is what speakers are you putting in? You said 6.5" components and 5.25" coax, do you have any models in mind?

xinsungx · 12-31-2006, 09:37 PM

5.25 coaxials: http://www.cardomain.com/item/INFREF5012I

6.5 components: http://www.cardomain.com/item/INFREF6010CS

moxom · 01-01-2007, 10:15 AM

Both sets will play pretty loud with about 20-30 watts, so a 100 watt per channel amplifier that is CEA-2006 compliant will do the job.
Why don't you install 6.5's in the rear deck as well?

htec17 · 01-01-2007, 11:27 AM

I dont know about that I have an SI with navi and changed all the speakers and the amp sounds great.i installed pioneers speakers all around with a kicker 500/5 amp.The sound is clear.

***Devin*** · 01-01-2007, 11:51 AM

Well, in pro audio, systems are designed to have 6dB of headroom between the RMS output and the peak output. This is rarely seen in car audio. This headroom is important to pass the voltage peaks in music. These peaks are very short and usually at a much higher amplitude than the normal program. If these peaks are not able to pass because of the inabilities of the amplifier, then the signal will be clipped. This clipped signal will damage speakers by causing them to overheat. So those 6.5" components, if given that 19VRMS (90W @ 4Ohms), would need an amplifier capable of about 38VPeak (360W @ 4Ohms). But where are you going to find a multi-channel with that much power? And your speakers are only rated to safely dissipate 32.8VPeak (270W @ 4Ohms). It is true that some drivers can be powered past their recommended ratings as long as signal is clean and there isn't overexcursion, but I would prefer my drivers and devices to have more headroom than what is seen in car audio.

xinsungx · 01-01-2007, 06:16 PM

i don't want to do 6.5 in the rears b/c i don't want to mess w/ things and try to make things bigger or what not...5.25 is the factory size right?

***Devin*** · 01-01-2007, 06:34 PM

Nope, 6.5" all around.

***dobiejoe*** · 01-01-2007, 07:36 PM

Cleansweep it and a good amp and you will be good if your not wanting to change the headunit.

12-31-2006, 03:00 PM	#1 (permalink)
xinsungx Senior Member Join Date: Sep 2006 Location: Durham, NC Posts: 125 iTrader: 0 / 0%	Amplifying aftermarket speakers So I will be ordering infinity reference speakers in the next few days...6.5 components for the front and 5.25 coaxials for the back. I'm not changing the headunit so I will need to get an amp but probably won't be able to get one until the summertime. Do you think I'll be fine till then? I don't want to mess up my speakers... ...also...the amplifier I have my eye on for now is the infinity reference 7451a 4 channel amplifier: http://www.crutchfield.com/S-qzsmd8w...20&I=108R7541A ...i found a good price for them for around 160 shipped. Would you suggest anything else other than these? (I would like it to be no more than 160) ...thanks in advance..:)

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12-31-2006, 03:28 PM	#2 (permalink)
*Devin* VIP Member Join Date: Sep 2006 Location: Deltona Age: 21 Posts: 108 Devin Flannery iTrader: 0 / 0%	I wouldn't run aftermarket speakers off the stock system without knowing the specs. The speakers would most likely be highly underpowered, damaging the speakers. That amplifier has decent power output capabilities for what you're doing, but I personally don't like the noise and distortion ratings. Harman pro products are damn good, but they're mobile lines are questionable, IMO.

12-31-2006, 05:05 PM	#4 (permalink)
xinsungx Senior Member Join Date: Sep 2006 Location: Durham, NC Posts: 125 iTrader: 0 / 0%	ok...so i guess i will have to hold off on the purchase of my speakers then..haha...so now i need some help on an amplifier...Devin..thanks for your suggestions ..i'll keep that in mind....ne more suggestions on a decent amplifier for the suggested price? If its around 100 i might be able to go ahead and purchase it right now...but i doubt that there are any good amplifiers for that price...right? Please keep in mind i'm only doing it so i don't ruin my speakers so i dont need ne thing fancy :)

12-31-2006, 06:30 PM	#5 (permalink)
*Devin* VIP Member Join Date: Sep 2006 Location: Deltona Age: 21 Posts: 108 Devin Flannery iTrader: 0 / 0%	Not any I know of with power ratings comparable to that of the Infinity. I don't want to make any generalizations but from what I've seen I like the specs of JL, Kenwood, and even Phoenix Gold have good ratings. I don't know how much power you're looking for. So I guess the question is what speakers are you putting in? You said 6.5" components and 5.25" coax, do you have any models in mind?

12-31-2006, 09:37 PM	#6 (permalink)
xinsungx Senior Member Join Date: Sep 2006 Location: Durham, NC Posts: 125 iTrader: 0 / 0%	5.25 coaxials: http://www.cardomain.com/item/INFREF5012I 6.5 components: http://www.cardomain.com/item/INFREF6010CS

01-01-2007, 10:15 AM	#7 (permalink)
moxom Senior Member Join Date: Feb 2006 Posts: 959 iTrader: 0 / 0%	Both sets will play pretty loud with about 20-30 watts, so a 100 watt per channel amplifier that is CEA-2006 compliant will do the job. Why don't you install 6.5's in the rear deck as well?

01-01-2007, 11:27 AM	#8 (permalink)
htec17 Senior Member Join Date: Jan 2006 Location: (954) davie Age: 30 Posts: 350 iTrader: 0 / 0%	I dont know about that I have an SI with navi and changed all the speakers and the amp sounds great.i installed pioneers speakers all around with a kicker 500/5 amp.The sound is clear.

01-01-2007, 11:51 AM	#9 (permalink)
*Devin* VIP Member Join Date: Sep 2006 Location: Deltona Age: 21 Posts: 108 Devin Flannery iTrader: 0 / 0%	Well, in pro audio, systems are designed to have 6dB of headroom between the RMS output and the peak output. This is rarely seen in car audio. This headroom is important to pass the voltage peaks in music. These peaks are very short and usually at a much higher amplitude than the normal program. If these peaks are not able to pass because of the inabilities of the amplifier, then the signal will be clipped. This clipped signal will damage speakers by causing them to overheat. So those 6.5" components, if given that 19VRMS (90W @ 4Ohms), would need an amplifier capable of about 38VPeak (360W @ 4Ohms). But where are you going to find a multi-channel with that much power? And your speakers are only rated to safely dissipate 32.8VPeak (270W @ 4Ohms). It is true that some drivers can be powered past their recommended ratings as long as signal is clean and there isn't overexcursion, but I would prefer my drivers and devices to have more headroom than what is seen in car audio.

01-01-2007, 06:16 PM	#10 (permalink)
xinsungx Senior Member Join Date: Sep 2006 Location: Durham, NC Posts: 125 iTrader: 0 / 0%	i don't want to do 6.5 in the rears b/c i don't want to mess w/ things and try to make things bigger or what not...5.25 is the factory size right?

01-01-2007, 06:34 PM	#11 (permalink)
*Devin* VIP Member Join Date: Sep 2006 Location: Deltona Age: 21 Posts: 108 Devin Flannery iTrader: 0 / 0%	Nope, 6.5" all around.

01-01-2007, 07:36 PM	#12 (permalink)
*dobiejoe* VIP Member Join Date: Feb 2006 Location: NJ Age: 38 Posts: 4,582 Joe iTrader: 1 / 100%	Cleansweep it and a good amp and you will be good if your not wanting to change the headunit.