amplifier features explanation?
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=84156
Printed Date: April 29, 2024 at 9:07 PM
Topic: amplifier features explanation?
Posted By: oldiegoldie
Subject: amplifier features explanation?
Date Posted: October 15, 2006 at 11:13 AM
ok folks, I'm tryin' to play with sum mobile sound components and would like the skinny on what the features mean on this used amp I bought.. 1. high inputs.? (is this impedence or voltage) 2. three variable knobs-Level[min-max]-Treble[0-+18db]-Bass[0-+18db] 3. jack for "remote subwoofer control" 4. three-way slide sw. "Crossover" 1st clik "highpass" 2nd clik "full range" 3rd clik "lowpass" 5. two more variable knobs 120hz-400hz 40hz-150hz. My goal is to put together a totally mobile system to run at remote locales without access to power. I have all the auto batteries needed and am aquiring the pieces now. The amp will power 2 subs only and a seperate amp will drive the mids and tweets in die-cast boxs. I want kickin' bass for this. The amp sez 640W. I figure must be to 2 ohm load. 320w-2. 4ohm will be 1/2 that. and 8 ohm even less.? I've got sum 15" subs of unknown manufacture and power handling. I've got an idea they might be around 100w, which could work for this ..?? very limited shoestring budget but feel I can pull it off. Suggestions..?
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Replies:
Posted By: coppellstereo
Date Posted: October 15, 2006 at 11:44 AM
1. use high input if you are not using RCAs
2. level = adjustment of gain
treble/bass adjustment (boost)
3. jack for a remote bass adjustment knob
4. Use 'lowpass' for subwoofers
5. (im not sure)
You are going to be going through batteries like crazy! You should invest in ac/dc converter or something instead of so many batteries
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Posted By: jonathancullen
Date Posted: October 15, 2006 at 3:45 PM
r u putting this insidea house? i did the same thing while i didnt have a car, i used a dry cell battery and left a battery charger on it all the time lol. you think the subs are 100 watts so your goin to put a 640 watt amp to them? and you want kicken bass, if you turn them up 2 loud your gonna see smoke. even though this is fun on old subwoofers if this is all you got and dont want to upgrade i wouldnt turn your bass boost up any. what are you using as a signal for these? r u putting a HU to the battery also or r u using a stereo.
Posted By: oldiegoldie
Date Posted: October 16, 2006 at 6:30 AM
many thanx to those who responded. my query about the input has to do with 'sensitivity'. in the old days(sic.) you had mag. carts. with anywhere from 5-75 mV. a tape head might punch out 600Mv. a tuner was another 'high signal' device. I'd like to know what the norm is for todays power amps when you have two inputs to choose from. the RCA's r obviously for direct from 'pre-amp' on ur head unit. so, is the 'high input' for an amplified source? yeah this is gonna run on car batteries as an outside project only. i got a kick butt unit inside already. ok..640W into one 2ohm load. 320w ea into two 2ohm loads, (I think) 160W into two 4ohm loads. So if I run this into the old 8ohm speakers it should figure out to 80W....????? is my thinking flawed.? oh, and I plan on driving this with an MP3 player.
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Posted By: witzeln
Date Posted: October 16, 2006 at 8:21 AM
am also curious. I want to use a car amplifier inside my house and I will not use a Head unit but instead an MP3 player or some sort of players for input source. The question is that how will I turn on the amplifier without using the remote source(the thing in between (+) and GND)? and yeah, are car amplifiers need a pre-amp?
Posted By: wvsquirrel
Date Posted: October 16, 2006 at 5:50 PM
As long as you're using the RCA low-level inputs then you don't need a pre-amp. Keep in mind though that if you are using the headphone jack on teh MP3 player as your input into the amp (phono to RCA connection), you will have a slightly pre-amplified signal. If your MP3 player has a "line out" jack (like on older CD players) I would suggest using that instead. Otherwise you'll need to adjust the volume of the MP3 player to no more than 3/4 (at least that's what my manual talked about).
What are you going to use to power the amp? A 12volt source or AC/DC converter of some kind right? Just run the remote line from it as well, only install a toggle switch on the line so you can turn the amp on and off. ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
Posted By: witzeln
Date Posted: October 17, 2006 at 12:14 AM
thanks bro (wvsquirrel)! last question (wvsquirrel). will I run the remote line to the positive or negative terminal of the power source?
Posted By: wvsquirrel
Date Posted: October 17, 2006 at 12:41 AM
Positive terminal, just like you would in the vehicle.
Also remember that you'll need to readjust the gains on the amp. Before they were set to match the headunit, now they will need to be set again to match the MP3 player 
When you choose an AC/DC converter, make sure you get one that will put out enough power for the amp. Also make sure the cables going from the power source to the amp are the proper size. It's just like installing it in a car, and all the fundamentals still apply if you want to do it right
Glad to be of help ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
Posted By: witzeln
Date Posted: October 18, 2006 at 12:57 AM
thanks! to save money, I'll use my spare power supply of my PC (230 watts) to drive a 750(max) watt amplifier.
Posted By: witzeln
Date Posted: October 18, 2006 at 1:20 AM
wvsquirrel, do you know how to compute the current that will be drawn by the amplifier from the power supply?
Posted By: wvsquirrel
Date Posted: October 18, 2006 at 1:31 AM
What is the make and model of your amp? It shoudl be listed in the manual. If you don't have it I can try to find it for you.
I run a 1000watt amp, and mine should be around a 50-80 amp draw (according to the manual). What is the amp rating on your power supply? ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
Posted By: aznboi3644
Date Posted: October 18, 2006 at 4:39 PM
Master...I didn't know you swung both ways lol
Posted By: witzeln
Date Posted: October 18, 2006 at 9:13 PM
I haven't bought it yet. the amp rating is 9 amp only. are you sure that is the rating of the amp that will be drawn from the power supply? or that is the amp that will be absorbed by the speaker in full load?
Posted By: wvsquirrel
Date Posted: October 18, 2006 at 9:21 PM
What make/model amp are you looking at. 9A seems too low for the current draw. ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
Posted By: master5
Date Posted: October 19, 2006 at 12:33 AM
HA HA very funny aznboi. But ignore most of anything I posted last night (most have mysteriously vanished regardless and for that I am grateful) Anyhow, someone posted earlier (I think golden oldie) asking about the difference between preamp (rca) and high level inputs on todays equipment. His "guess" is correct. The preamp input is for the preamp signal from head unit to processors/amp(s). The high level input if so equipped on many amplifiers is for an amplified input such as using in conjunction with a factory headunit which does not have any rca's or preamp signal readily available without "digging in" to the unit.. The H/L input signal is generally not as clean but it gives more options for ian amplifiers use...ie: adding an amp for sub or more power to the mids/highs w/ a factory or a cheaper "non preamp" output head unit. I rarely use the high level inputs but in one or two circumstances they have served thier purpose for me. See you all around. -------------
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