Peavey 6505+ NO BASS FREQUENCY EQ

Here you go. Service Manual free download schematics datasheets eeprom bins pcb...

Bass boost simply adds DB or gain to the bass signal. Some like it, some dont.
The frequency knob is the Low Pass Filter (LPF) that cuts off the amp output above
the set frequency. A bass system usually cuts off below 400 HZ and more often 200HZ.
A good, rattle your car bass note is in the 25-80HZ range or lower but most amps and audio
input devices cant attain a good low note with clarity.
"Low-pass filter allows only frequencies below the crossover point to be amplified. A high-pass filter allows only frequencies above the crossover point to be amplified - useful for keeping low bass away from small speakers, so they can play more efficiently."
Checkout Crutchfields Glossary of Car Amps.
http://www.crutchfield.com/S-LPyoWWgD5qN/learn/learningcenter/car/amplifiers_glossary.html

Assuming that you eq is installed in your system correctly add a source like a cd of the type of music you will be putting through the system. Now starting at 0 on all frequencies adjust to your liking. Try to avoid going above 0 as much as possible because this will be adding to that particular frequency and could damage your speakers if done incorrectly.

If there is too much bass lower your sliders to the left. If there is not enough highs boost the sliders to the right up to about half way then start decreasing the bass to get the desired effect. Small increments is important.

I found that if you go to your local music store the people there are more than willing to help you.

The preamp section has a problem. It could be anything in the preamp but is OFTEN the input jack itself. They take a lot of abuse.

Also the insert jack contacts that forward the preamp to the power amp if no external FX are used can go bad.

Additional things are circuit board cracks caused by rough handling and also controls that have had the knobs mashed in which can destroy the potentiometers they are connected to.

the amp probably has a x-over knob, a bass boost knob, and an eq knob. the eq is probably an internal crossover switch that will take the output from either high range (tweeters) or full range (6x9s) or low pass (subs) leave it on low pass. the bass boost however, will add distortion if turned up too high. its not noticable in the car, actually it sounds louder in the car but if you open the trunk and listen, you can tell its distorted bass and actually frying your speakers. the x-over knob is used to tune the frequency at which the amp stops pushing out bass tones. if you like rock music loud, turn it up higher, if you like low deep rap bass, turn it lower. keeping it too high might give you bad sound from either type though. ALSO THE GAIN OR LEVEL.IT IS NOT TO MAKE YOUR SUBS LOUDER IT WILL BLOW THEM .the gain is used to set your amp to your head unit which there is a procedure to do it.

Hey i'm no expert either but maybe just maybe your amp has a subsonic filter on it which cuts out the lowlow bass maybe check that and either disengage it or turn it all the way down if it even has one thats all i can think of unless you have a ported box and going below the boxes tuning frequency other than that im as stumped as you are-good luck with it

Start with a clean setting - zero cut and zero gain on the Eq. Play a song close to the amp, and then move away, playing the same notes. Do you still get the distortion? Change lower the input gain and repeat the test. Lower the output gain and repeat. Are any outboard distortion pedals in the mix, such as overdrive? Eliminate them. Run straight through from your axe to the amp. Check for any distortion settings. Set everything including reverb to zero. When the distortion disappears, this is your base setting.
Change only ONE parameter at a time. When the distortion comes back, you have found your problem.+

Hi fingers 1

There will be some overlap in bass response that you may need to tune out to tone down the boomy bits. You could tune this out with a 31 band EQ Another approach is to use a crossover or low pass filter to the subs to get some control over your bass frequencies. Another thought, if you're using the rig for stage work, how does it sound out the front. It may be standing waves created by the bass bins, moving them to different monitoring positions may also help.

I am more than happy to answer any other questions you may have about it, just give me a hoy :) If you are still unsure, or have problems, then before you give a rating for this advice, please get back to me and we can try some more things.
Thanks for using FixYa, If you consider the advice I have given you as sound, a FixYa rating is a great reward for my efforts to help you. Cheers.

regards
robotek

I have an Alpine 9887 you have a different eq than just trebel and bass the only way to get you bass an trebel setings are to install the imprint stoftware now if thats the route you go it tunes your radio to what it thinks it should sound like it's for sound quality not for alot of bass been there done that I have the software but you need to take it to a good alpine dealer to have it installed good luck

Hi there,
Although I am not familiar with the Zoom HD 8 Track I am a former sound engineer so may be able to offer some general advice.
Firstly, because the wave pattern of low frequencies is very long, there are a number of things that will greatly effect bass response caused by standing waves.
1) The position of your bass monitors. Ideally these should be low down but not directly on the floor, especially if the flooring is wooden.
2) Try your monitors/speakers at a slightly different angle. Bass can bounce off walls, back towards the sound source and phase out the signal, rather like a noise cancelling system.
3) Try listening to the sound in different areas of the room. You will be amazed at how the sound pressure level will vary, simply by you moving from one position to another.
4) Never put bass tracks exactly at centre, always offset them slighly by a few degrees left or right.
5) Do some of your mixing using headphones, you will not have to worry about standing waves. But remember that things sound very different on speakers in free space.
Strangely, the reason you are getting distortion when you turn things up is probably because your bass is on the verge of over modulation to start with. Really bass is felt, not heard. You could try is to decrease your mid and high frequencies a little. The ratio between high frequencies and low ones will then increase by default and your bass may feel heavier.
What are you mixing?