I noticed (and did a search) that nobody ever talks about tuning their stereo systems. I mean why spend all that money on audio gear and not get the most out of it. I did a lil write up. Feel free to add any comments to this or correct any mistakes that I've made. A great source of car audio information is at
http://www.elitecaraudio.comRead the install clinic articals. They are written by a guy named Steve Head. He has probably forgotten more about car audio than all of use on this forum know.
What is my back round you ask? I competed in IASCA and USAC car audio (sound quality competitions) for almost 6 years finishing 8th at the USAC finals (26 cars in my class). I got sick of car audio decided I wanted to go fast so now I have a SRT-4 on nitrous.
So, all of the car audio gear you ordered from EBay and various online vendors have finally arrived at your door step! You call your buddy, buy a case of beer and you tear into the installation like mad men!! the two of you are as busy as a one legged man in an arse kicking contest!!! The dust settles, the beer is gone and “ta-dow”! Your gear is installed, looks good and you are ready to rock!!! You turn the system on and yeah it’s louder, has more bass but other than that you and your bro are not overly impressed. No fear my friend, this post is a basic guide to help make your system sparkle!!!
I suggest a couple simple tools that if you are serious about car audio you will use over and over again.
Radio Shack SPL meter (30.00)
Audiophile disk with band seperated pink noise (13.00)
This tuning guide is not all inclusive. It’s just a lil something to give you a good basic tune for your system.
DISCLAIMER: I’m far from an expert! Everyone has different taste in music and what “good” sound is! At the end of the day YOU need to like what’s coming out of your speakers. Also most of these tips are based on my OPINION and you know that’s worth!!!
Ok with that said let me address some of my car audio beliefs.
• You don’t need a Head Unit with more than 4 volt signal output! Most amps and other gear (read crossovers and EQ's) will reach full power with as little as 2 volts!!
• Get decent RCA cables, but no need to spend 8 million dollars on cables. If your system has no noise with your current RCA cables, you have found the best cable for your. You want to get UTP cables (unshielded twisted pair).
• Don’t waste you money on CAPS!!!!
• A lil dynamatt on your doors goes a LONG WAY!! Car audio speakers are designed to be installed in an infinite baffle enclosure. Use some Dynamatt to cover up all the wholes in the door and your system will sound better.
• Get a good EQ. If you are into sound quality, it’s a good investment.
Ok let’s talk about system set up. Their are many ways to set up your system but this is how I set mine up.
• Set Gains (HU, external processors, amps)
• Set speaker output levels (either individually or as a set)
• Set Initial crossover settings for each speaker set/input time alignment settings if applicable.
• EQ the system.
• Adjust speaker Phase (or polarity) Do one speaker set at a time, and then re-adjust as a complete system.
• EQ again.
Set Gains
This is very simple and normally never done! Start with your amp(s), set the gains so you hear nothing. Give your amp gains about 1/4th a turn. This is just for starters. Go back to you HU, put on some dynamic music!!! A good recorded rock song will do (think metallica).
Start with you HU volume all the way down, turn up the volume until you hear the system start to break up. Once you hear slight break up turn the HU volume down just a touch. Now go to the next piece of gear in the audio chain, be it an EQ or Xovr. Turn up the gain on that piece until you hear some system break up, then back it down a touch. Some EQ’s/xovr’s have LED’s that let you know when you have reached the full amount of signal that it can take, this makes life a lil easier. These pieces of gear will let you know if you are at the peak voltage or if you are over driving (causing distortion) the unit. Ok now that’s done, go to your amp(s) do the same thing with the gain control on the amp(s) If you have a multi channel amp you will need to do this for each channel or channel separately or each channel pair Some high end amps will have a gain control of each channel. Now all of your gains should be close to evenly matched.
Set speaker output level
Most of you don’t give half a rat’s ass about good staging and imaging so this is mainly for those folks who do. You may have seen me ramble about Path Length Differences and time arrival in a couple of posts. This next tuning step helps with this. Since most of use don’t want the added install hassle or don’t want to take up foot room using kick panels, Time alignment is a must when using factory locations. When I’m setting up a car I will set all the speakers output to the same output or loudness. You notice I said same loudness, not same volume setting. In my last competition vehicle my passenger side kick panel speaker was set two clicks lower than my drivers side kick panel speaker to get the same output. I do this with my handy dandy Radio Shack SPL meter. I’ll set it in the middle of the car then I’ll set each speaker loudness output to 80 decibels. If you can’t control the output of each speaker then ensure the output of each speaker pair is the same. 80 decibels was just a number I used!! You can use 80, 70, 14, it don’t matter. What matters is that each speaker or speaker pair is playing the same or close. A one db difference won’t really matter.
Crossover settings
Two things will decide crossover settings. 1- The frequency range of the speakers and personal taste. Since our cars are a sedan the sub bass has to pass through the back seat and rear deck so I like to cross my sub over at 120 Hz @ 18db per octave. You will hafta play around with this setting to see what works best for your system and your taste. For the front speakers, I like to cross them over as low as they will play with good output and without distorting. This way it won’t sound like all of your bass is coming from the back and all of your highs and midrange are coming from the front. If I am using a 6.5” speaker I start at like 65 Hz and up. If I’m using a 5.25” speaker I’ll start at like 85 Hz and up.
Time alignment - the easiest way to set up time alignment is by using the audio tools on alpines website. Break out the tape measurer, take your measurements from each speaker, input them into the Alpine T/A calculator, then input these time measurements in your HU or signal processor. The name of the tool is Alpine I-personal or something like that. It will convert your measurements in to time increments.
EQ – When I set my EQ I use three tools 1- Radio Shack SPL meter.
2 – my audio disk with band separated pink noise or sine waves. 3 – My final and best tool, my EARS!!! I will use my pink noise disk and play each track that corresponds with a band on my EQ. so lets say I have a 10 band EQ and the bands are broken down like this: 63hz, 80hz, 100hz, 250hz, 500hz, 1k, 1.5k, 2.5k, 5k, 12k ( just examples) I will play each pink noise band that equates to my EQ bands and lower/raise that band until it reads 80 decibels on my radio shack meter (again 80 is just an example). Once you have done this, the system will probably sound a lil flat. Now adjust it by ear. I like a lil bump in my bass and mid bass so I’ll add a lil on the eq at 63 Hz and 80 Hz. If you want more deep bass, just turn the sub up a touch.
Polarity/phase – Phase is another part of tuning that most people don’t get into. It’s hard to get different sets of speakers to play in “absolute” phase because some parts of the frequency spectrum might be in phase while others are out of phase. Let’s say you have a speaker that’s out of phase at like 80 Hz. This will make your mid bass sound weak and you will hafta use your sub to try and compensate, but then it sounds like most of the bass is in the back of the car. Another example if the sound waves at lets say 1000hz are in phase, this could make that portion louder making the system sound screechy. I know of two ways to combat this. 1 – A very expensive phase processor (PPI use to make one) 2 – Reversing one of the speaker leads. For the purpose of this guide we are going to use method # 2! By switching the lead of one speaker you are changing the phase of that speaker by 180 degrees, this may help get rid of trouble spots you are having in your sound or it might not. It might make things sound worse. The good thing is, it cost you nothing!!! And you can always put the speaker leads back to normal. After I’ve done this for my tweeters, midrange and mid bass, I’ll do it with my sub. Sometimes by switching the polarity (swapping leads) it will make the sub bass blend better with the rest of the system.
EQ AGAIN – Now that you have tackled the most time consuming parts, go back and listen to the system as a whole. Try to use your EQ to fix rough spots in your sound. Remember it’s easier to cut a frequency than to boost a frequency. Oh I almost forgot. Take a break before you EQ the car for a 2nd time. Send your wife or girl friend to the store for some beer. Drink two beers and let your ears rest for about 45 minutes, then tune the system to your liking.
Trust your ears!!!
It’s YOUR system and it should sound how YOU want it to sound!!! Have fun tuning!!! I’m sure I’ve left out a ton of stuff so if you have any questions just PM or post on here. If I don’t know the answer I’ll try to direct you to a site or person that does.
stereo tuning 101
Linear Mode
