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Equalizers and Voltage

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=58884
Printed Date: June 05, 2024 at 1:39 AM


Topic: Equalizers and Voltage

Posted By: action1978
Subject: Equalizers and Voltage
Date Posted: July 05, 2005 at 5:15 PM

I am planning on running a HU that delivers 8v to the preamp outs. If I put in a pre-amp equalizer will my amps still be getting 8v?  I was told that the equalizer will put out the voltage that it is designed to put out but none of the Eq's I see say anything about preamp voltage.  If I run an Eq is there any reason to have more than 2v pre outs?  I saw one Eq that said 3000 watts.  does that mean it has built in amps?  Should I even bother with the Eq?  Why am I finding new Eq's for like $20.00? and some are $400.00??

Thanks,  I don't know crap about Eq's in car audio situations.




Replies:

Posted By: haemphyst
Date Posted: July 05, 2005 at 6:45 PM
action1978 wrote:

I am planning on running a HU that delivers 8v to the preamp outs. If I put in a pre-amp equalizer will my amps still be getting 8v? I was told that the equalizer will put out the voltage that it is designed to put out but none of the Eq's I see say anything about preamp voltage. If I run an Eq is there any reason to have more than 2v pre outs? I saw one Eq that said 3000 watts. does that mean it has built in amps? Should I even bother with the Eq? Why am I finding new Eq's for like $20.00? and some are $400.00??

Thanks, I don't know crap about Eq's in car audio situations.




This is several question/answer sessions, so let's break it down, OK?

Q: I am planning on running a HU that delivers 8v to the preamp outs. If I put in a pre-amp equalizer will my amps still be getting 8v?
A: If your EQ has an 8v out, yes, you would still be able to feed your amps with an 8v signal.

Q: I was told that the equalizer will put out the voltage that it is designed to put out but none of the Eq's I see say anything about preamp voltage.
A: This is correct. Once you put an EQ in place, the head unit no longer is "seen" by the amplifiers. ANY of your better quality manufacturers will be able to provide you with an output voltage for their gear...

Q: If I run an Eq is there any reason to have more than 2v pre outs?
A: No more reason in an EQ than there is to have a head unit with 8v outputs... It SHOULD allow you to turn your gain controls down, giving better S/N ratio, but it won't necessarily make it "louder", if this is what you are looking for.

Q: I saw one Eq that said 3000 watts. does that mean it has built in amps?
A: Possibly, and I bet they are missing the decimal point somewhere in that "3000". Probably more like 30.00 watts

Q: Should I even bother with the Eq?
A: Up to you... Me? I'm a fan of simplicity, usually. The fewer components in a signal path, the better - less stuff to muddy things up. "Graphic" EQ's can actually do more harm than good, if not used correctly. A good, true "parametric" EQ is MUCH prefered, but usually, way more expensive.

Q: Why am I finding new Eq's for like $20.00? and some are $400.00??
A: Because you get what you pay for... In car audio, like most everything else in life, the more you spend, the more you get. And *ONLY* 400.00? That's CHEAP, if it's a good one. You have not been looking hard enough. LOL I have two UCSPro 31 band parametric EQ's with a pricetag of over 800 EACH! Not bragging, just saying, there is more expensive stuff than that out there...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: us_test
Date Posted: July 05, 2005 at 6:53 PM

See what  haemphyst said he makes good points and also see below:

What HU are you looking at?  The majority of HUs which deliver 8v out have a nice built in EQ so I would start with the built it, tweak it, or better have someone else tweak it if possible.  The clarion EQ EQS774 is a nice 7 band with 3 RCA inputs (front, rear and sub) which puts out 7Volts you can get it for $75 shipped from e-bay.  The more volts the better the signal to the amp which will be boosted.  Some older amps (talking a few years back) do not play well with 7-8V inputs but the newer amps are OK (make sure you set the gain properley ... see this site or do a search on set gain and you'll find a lot of info. regardless of your amp being new or an older model).  Price = quality $20 EQ will cripple your system more than help.  Stay away from power EQ (built in amp), the EQ's job is to shape the sound not boost it.  The powered EQ will distort the signal and hurt your system rather than help. 3000 watt EQ does not exist for a car (no company that I know makes it).  Think about the size of a real 3000 watt RMS amp, it is 6 to 10 bigger than an EQ because to make power you need a lot of componets and components  = real estate space or size.  If you decide to go with an EQ I'd recommend the Clarion.  Audio Control 4.1 is also nice (you can get one use for $100.



-------------
(1) Kenwood Excelon Head Unit KDC-X589 (24 bit Burr Brown DAC, 3 X 4 volt RCA).
(1) RF Punch 250A2 - running the components.
(1) Hifonics 6.5" Atlas Components (18db crossovers).




Posted By: action1978
Date Posted: July 06, 2005 at 9:58 AM

Hey thanks!

Haemphyst.  You say there is no more reason in an Eq than there is a head unit with 8v pre outs.  What does this mean?  Back in the day when I was into car audio I had everything done for me.  I got a 4v HU to replace the 2v I was running.  It made my system sound a lot better, and louder.  If 8v is not necessary what should I consider regarding preamp voltage when shopping for head units?

us_test

I have been looking at the Rockford Fosgate RFX9420 head unit.

You say that 7 or 8v is no good with older amps.  I am planning on running 4 fosgate amps.  3 of which are the older late 90's all black amps.  Should I avoid the higher voltage with these?  what should I use? 4v?

Thank you all very much.  Hopefully I can help you with something someday. 





Posted By: us_test
Date Posted: July 06, 2005 at 10:18 AM

Check your manual first.  The gain would have to be set lower if using 8v HU.  I have a late 90's (1999) black punch 250A2 (see my sig) running Kenwood Excelon 4v HU and it works like a charm.  I tried to look up the max voltage input for my amp but now luck yet (we can safeley asume it is more than 4V).

I know that the Rockford Fosgate RFX9420  head unit has 2 pair adjustable input so you can adjust he input level there.



-------------
(1) Kenwood Excelon Head Unit KDC-X589 (24 bit Burr Brown DAC, 3 X 4 volt RCA).
(1) RF Punch 250A2 - running the components.
(1) Hifonics 6.5" Atlas Components (18db crossovers).




Posted By: haemphyst
Date Posted: July 06, 2005 at 8:41 PM
action1978 wrote:

Haemphyst.  You say there is no more reason in an Eq than there is a head unit with 8v pre outs.  What does this mean?  Back in the day when I was into car audio I had everything done for me.  I got a 4v HU to replace the 2v I was running.  It made my system sound a lot better, and louder.  If 8v is not necessary what should I consider regarding preamp voltage when shopping for head units?

Thank you all very much.  Hopefully I can help you with something someday. 




Yes, if you simply swap a head with say, 2v for a head with 4v, WITHOUT re-setting the gain, OF COURSE it's going to be louder - not necessarily cleaner (better). The reason for this? You are going to need HALF as much volume control, and if you do not pay attention, you will drive your amps to clipping TWICE as fast. This will blow your speakers faster than too much power - especially tweeters. Additionally, the human ear will ALWYS decide the "louder" system sounds better, whether the distortion is higher or not... It's called psychoacoustics, and this is probably the basis for your claim that it sounded "better".

It is perfectly acceptable to do this (head swapping), but as mentioned, you MUST make certain you adjust for the additional signal, buy re-setting your gains to a LOWER position on the dial.

I never said that high output voltage was not NECESSARY... I run an 8v deck myself. Higher output voltage allows for a lower setting on the gain dial at the amplifier, providing a quieter output (less noise). The more important spec to look at AFAIAC, is output impedance. VERY few manufacturers will provide it, but always look for the lowest output impedance you can find. This will provide for a better S/N ratio, and usually indicates better output coupling - direct or resistive (good), rather than capacitive coupling (not as good), which will usually allow better low frequency response... It will also make for a quieter installation, with less chance of noise being induced into the signal cables between the headunit and the amplifier.

-------------
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."





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