What to look for in a car amp?? - diyAudio
Go Back   Home > Forums > General Interest > Car Audio

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 1st April 2009, 03:09 PM   #1
Dan2 is offline Dan2  South Africa
diyAudio Member
 
Join Date: Sep 2005
Default What to look for in a car amp??

hi,

i haven't bought many amps, and i have only set up about 3 so i can't say im too clued up on all the features that amps have. i know the basics, like if it's bridgeable, got crossovers etc, but is there anything i should be looking out for when buying a new amp??

please bear in mind i am a student and haven't got tons of money to throw into a new amp. i also have relatively cheap speakers - but they work and i am happy with their peformance.

at the moment i am running 4 speakers and one sub in my sedan.
the fronts and the 12" sub are connected to a 4 ch 1000w jenson amp. i want to get an amp with similar power handling.

there are 2 problems with this amp i currently have:
first, it has crossover distortion, which is not a problem with the sub but sucks on the mids.

second, there is not enough gain for the sub unless you put the bass boost on, which makes the bass very boomy, but then there is more than enough power for what i need.

so what should i look for??
  Reply With Quote
Old 1st April 2009, 11:03 PM   #2
ppia600 is offline ppia600  United States
diyAudio Member
 
Join Date: Jun 2007
Location: Louis y ana
If your Jensen says 1000w (max), the equivalent of most US made amps would be about 50watts rms by four (200 watts). I like ppi, orion, zapco, phoenix gold for example. You should be sure to check the RMS power ratings, they are more realistic that the peak/max ratings a lot of amps give you. Also, you want a low distortion percentage at that RMS rating. RMS is pretty much the term for continous output power. Peak is just for a few milliseconds and is pretty much a useless measurement in my opinion.
__________________
Don't worry... you can always turn the gain down!
  Reply With Quote
Old 2nd April 2009, 02:25 PM   #3
Dan2 is offline Dan2  South Africa
diyAudio Member
 
Join Date: Sep 2005
thanks for the info, but.....

50wrms sounds a bit low. for example, my sony 2ch amp (250w) is about 50wrms per channel (if i remember correctly) and that doesn't have as much power as my Jenson. i am not saying that you are wrong, that's just what it seems to me. ( maybe south african watts are different from US watts )

my friend has a starsound amp, 800w 4ch (70w rms), which also doesn't have quite as much output, but does sound better ( i had it running in my car for about 2 weeks to test it for him)

my amp i got for free with no manual so i don't know what it's rms value is.

so what is a low ditortion percentage?? will that include crossover distortion?? (i am not talking about the high- and low pass filters, i am talking about the distortion that can be heard when the output signal crosses from positive to negative)
  Reply With Quote
Old 3rd April 2009, 03:44 AM   #4
jol50 is offline jol50  United States
diyAudio Member
 
Join Date: Nov 2007
I would guess there is something wrong with the amp if it has that type of distortion. Most amps don't even have a bias adjust anymore and the main issue is clipping at max power. Jensen is a budget amp, the ratings are not the same as a more expensive brand. Here you can find amps all over from pawn shops to ebay, if you shop some you can find a great deal. I would try to go class D on subs if you can, they require less power and wiring in the car.

The amp could be 4x50rms, that would be something like 1x150 if half were bridged on a sub if it is 75rms/ch at 2 ohms. Yeah some of those amps they reduce the gain because people turn the boost way up, or I think that is why. Personally I would not use most 4ch for subs, many don't have as much of a power supply as a 1 or 2ch does but it depends on brand.

Google the name/model and you might find a manual online.
  Reply With Quote
Old 3rd April 2009, 04:23 AM   #5
ppia600 is offline ppia600  United States
diyAudio Member
 
Join Date: Jun 2007
Location: Louis y ana
In 1999 or 2000 Jensen had some amps that I think were made in America. (maybe not) I tried to get my supervisor to order some but they always bought the cheapest stuff from some of the flea markets. The Jensens were just a hair more expensive and I still couldn't convince them. If you have one of those, I could believe 100watts rms by four but its still unlikely. Do you have the model number or maybe a pic or two?
__________________
Don't worry... you can always turn the gain down!
  Reply With Quote
Old 7th April 2009, 12:18 PM   #6
Dan2 is offline Dan2  South Africa
diyAudio Member
 
Join Date: Sep 2005
Quote:
Originally posted by jol50
I would guess there is something wrong with the amp if it has that type of distortion. Most amps don't even have a bias adjust anymore and the main issue is clipping at max power.
well i did change the resistor between amp ground and power ground - it used to be 10 ohms but that gave some engine noise. i think i changed it to 100 or 1k ohm, can't remember.

i will get the model number, and i might have some pic's, i will check.

the one thing i hate about this amp is the bass boost. with it off, the gain is a little low, and with it on there's tons of low rumbly bass that doesn't seem to reach frequencies high enough to mix with my mids. some rock and dance songs seem to have no bass while others have way too much.

also, should i be looking for any kind of features on an amp? my friend's amp has a subsonic filter (high pass i think) but i don't know if its too important.
  Reply With Quote
Old 7th April 2009, 04:50 PM   #7
jol50 is offline jol50  United States
diyAudio Member
 
Join Date: Nov 2007
Subsonic is good for running ported subs hard or maybe IB subs. Ported can unload below tuning and xmax the sub easily, and IB can be limited in power handling at low frequency. It becomes a problem when you get to the sub's limits. Most newer amps have what you need with HP/LP filters and variable boost. If you need it a few can bandpass for a midbass or maybe mid. A few have parametric EQs for subs that could work nice in certain apps. A warranty and/or worthy brand is likely most important. You might be able to change the boost circuit to work better, but I've never done it.
  Reply With Quote
Old 8th April 2009, 07:09 AM   #8
Dan2 is offline Dan2  South Africa
diyAudio Member
 
Join Date: Sep 2005
that makes sense. im using a sealed enclosure so that wont bother me.
  Reply With Quote
Old 29th April 2009, 04:56 AM   #9
ke4mcl is offline ke4mcl  United States
diyAudio Member
 
Join Date: Apr 2009
Location: miami, fl
im a fan of linear power amps, matts, and mcintosh. macs are pricey. mmats can be had very reasonably if they are last years stock or older. they are well built. linears are very well built but getting service can be a pain and they are getting up there in age.
__________________
certified packrat
  Reply With Quote
Old 29th April 2009, 10:31 AM   #10
Dan2 is offline Dan2  South Africa
diyAudio Member
 
Join Date: Sep 2005
i was in my friend's hatch the other day, he has a 2000w 4ch with a DVC 12". that had really hard hitting bass which sounded really good - only thing is doesn't know if all 4 channels are used for the sub ( 2 x bridged) and he couldn't remeber what sub it was. unfortunately i didn't get a chance to check it out.

i was thinking of gettin a 1600w 4ch - my sub is a kenwwod 12' SVC 800w so a 1600 w would match the sub (800 bridged).
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 07:42 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2