Basic system adjustment and tuning tricks.

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VW337
Meatgician
Posts: 2780
Joined: Wed Dec 06, 2006 9:53 am
Location: PORK-Land OR

Basic system adjustment and tuning tricks.

Post by VW337 »

Below will be listed a few tricks they will not tell you. These tricks with the proper application will improve your sound without costing you anything and will usually take very little time to implement. All proceeding steps take into account that some people do not have access to a DMM or Oscilloscope which would allow for the most accurate adjustments.

In order to do this you must be able to recognize the sound of clipping and distortion. If you do not, do not attempt this. You can damage your speakers!

Amp Adjustment (Multiple Amps)

1. If you have multiple amps disconnect all the RCA’s except the ones connected to the amp that is powering your front speakers.

2. Set all of your controls on your radio flat (0 bass, 0 treble, etc.). Set the high-pass crossover on the amp (if variable) to around 100 Hz (120 Hz for small speakers 4” etc.).

3. Turn the gain all the way down on your amp, turn your stereo on at this point. Your speakers should be making very minimal sound.

4. Turn your stereo to it’s maximum volume, but avoid clipping/distorting your speakers.

5. Now back the stereo’s volume to just about 1/16 – 1/8 less than max.

6. Turn the gain on your amp up at this point until you start to hear clipping/distortion and then back it down just a little, like you did the volume on your radio.

7. Now you adjust your crossover (if variable) to a lower frequency, going lower than 60 Hz is not recommended for most speakers. Keep listening for the distortion when you start to hear it turn the crossover back up a little.

8. If you have an amp for your rear speakers repeat steps 1-7 on the rear amp. Once you do this make sure you reconnect the front amp listen to see how well the amp/speakers balance adjust the rear amp gain down until you can just barely hear that there are rear speakers, this will help provide a better sound stage.

9. Now if you have a sub amp you’ll need to repeat steps 2-6 keep the other amps connected, keep in mind this is a sub amp so replace high-pass with low-pass and the recommended range is 60-80 Hz (up to 120 Hz for 8”), once you have completed steps 2-6 adjust the volume on your stereo and see if the sounds stay balanced from high to low volume in most cases you’ll have too much or too little sub adjust the gain accordingly and try again.

10. When you have all amps running listen for a loss of bass/midbass, from when it is one amp or the other. If so please check the section on phasing when you finish your adjustments.


Phasing

This is a critical part of sound quality that is rarely if ever touched on in any tech sheets or installation notes. In a vehicle there are multiple angles and materials in the interior. What does this mean, this means although your speakers may be electrically in phase they may not be acoustically in phase. Crossover’s will also affect phasing between speakers especially in component sets. You can buy an expensive time alignment device but unless you are a serious competitor this may not be needed. To do the next steps you’ll need to be in a fairly quiet area and you’ll need to have your radio adjusted to a good listening level, with a very dynamic song that you are familiar with.

1. Disconnect your sub-amp signal, play your front and rear speakers together and listen closely to the music.

2. Switch your rear speaker leads (not the power but the signal leads going from the amp to the speakers themselves) electrically out of phase, meaning + to – and – to +. Listen closely to your music again.

3. If you have more mid-bass leave the wires switched if you have less switch them back.

4. Reconnect your sub-amp signal, listen closely to your music again.

5. Unplug the wires going to your sub enclosure and plug them back in electrically out of phase. Listen closely to your music to see if you have more or less mid-bass. If you have more leave it, if you have less switch it back.

The above steps are suggestions and not necessarily a cure for any problem but you may find that it can make a big difference. You can change the electrical phasing on any one speaker and notice a difference good or bad, but it is typically recommended to do in pairs. From my experience you’ll see the best results when switching the phase on tweeters in a set of components that are mounted more than 6 inches apart.


More or Better Sound

1. Tweeters pointed to reflect off of glass will typically show a +3db gain (remember to wire out of phase).

2. Vehicles will typically rattle audibly around 125 Hz, set your crossovers accordingly.

3. An internally cross-braced sub enclosure will yield more output than a completely airtight enclosure, do both. An airtight enclosure is less likely to distort than a leaky box.

4. Multi-texture installs tend to create more predictable sound. If it’s metal cover it with a sound deadener, if it is wood cover it with carpet or vinyl. You’ll have fewer reflections that can cancel some frequencies.

5. A properly installed and adjusted system sounds better than a higher quantity of the same equipment.

6. Most amps are not capable of a 1 Ohm mono load, if you have
two 4 ohm woofers wire them stereo or with the coils in series
with the amp bridged.


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I think we've established that "Ka Ka" and "Tukki Tukki" don't work.
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