US1 Fountain

iTrader: (1)

I just finished installing 2 amps and am in the process of tuning them, but have absolutley no idea what some of the adjustments are and where they should be set. Audio terms are foreign to me. I'm a 'this' or 'that' thingy person. I'm looking for at least a starting point (or a must be set at ) and which way to adjust (up or down) if need be. Specifically the filters 'slope' and the 'frequency' adjustments. Also the 1x/10x frequency switch and the infra sonic adj. on the mono amp.
The basics I understand: HP for the 4 channels, input voltage and sensativity (gain)
Not looking for that thumping bass, but just a good sound as far as the free airs will deliver.

My system;
2) 10" free air subs mounted at drivers and pass. feet sides powered by a mono amp.
http://mobile.jlaudio.com/products_a...php?amp_id=251

2) 6x9 Babbs in the rear bench seat as the 'rear' amps channel, and 2) 5 1/4" Babbs mounted at the sides rear seat up about shoulder height as the amps 'front' channel.
4 channel amp http://mobile.jlaudio.com/products_a...php?amp_id=254

note:
The JL manual says my subs/mono amp will work best at 24dB slope, but when i did that, the subs popped like no tommorrow. Sounded like the cone was going to come out of the frame. With volume and gained turned way down too the 2nd time I tried it. If I leave it at 12dB, it's fine, but what happened?

1 final question for the pros. Do you prefer to set the gains by ear or a tone cd and DMM as suggested by JL? I've read about using a cheap amplified speaker to get the HU's max volume setting before distortion, then going to each amp and doing the same adjustment leaving the HU at the previously tested max volume instead of the standard 3/4 volume . Seems like a more accurate way w/o going to the osciloscope route.

My other option is to have the stereo guys come to my house to adjust which we have discussed, but they are car guys and not boat familiar. So thinking it might be a waste of my money.

As always, any suggestions are greatly appreciated.

Thanks

phragle

iTrader: (3)

well..you have adjustments, that are beyond me (some of them) but the basics how I have always done it, start with the front speakers, pull the rca's for the rears and the sub so only the fronts play, adjust the upper cut dwon untill you loose the shrillness and the low pass up untill the bass cleans up, then work the gain up untill you get distortion at high volume and back it down a little, same with the rears, then the sub, the freq. could be 1 of 2 things depending on the amp. 1 is the upper level freq cut off or it could be freq booster (to help tune enclosures)and have a sep control for the crossover point. slope is how it rolls down from the crossover point, play with things untill the bass is tight and has good punch but is not muddy, work the gain up little by little untill it get distorted back it down a tad and remeber the setting, now turn the gain down on the sub, play your standard music and work the gain on the sub up untill its at the desired level without going past your mark. ideally you want the tone controls on the deck all set to neutral, you want your bass to come out of the amp and sub, not by turning the bass up on the deck. unless your trying to do some kind of competiton set everything up by ear, afterall its your ears your trying to please. unless your cranking it to 11 when your setting it up, this is a safe way, and by playing with everything, you will know what to change to alter the sound. remeber too on most decks anything over 3/4 volume is NOT louder..it just starts adding distortion making it seem louder.. power doesnt kill speakers distortion does.

BillR

Tune by ear - thats what is going to listen to it.

Let me try to help some.
Initial settings (pwr off):
L to R on sub amp
Preamp Output: n/a
Amp LP filter: 24db slope - set freq dial to 55 - 60
Bass Control: infrasonic switch on (to right side) LF boost 0 (for now)
Input: Input voltage to low, signal sensing- off, set input sens to 12 O'clock

Ok, now you have the bass amp "basically" set up.

Now lets set up the mids/tweets amp:
Front AND rear filter controls: X1 and 12db slope for both, Filter mode: HP, Filter Freq: approx 80
Front and rear input: Input voltage-low,set levels to 12 O'clock. 2 or 4ch depending on how you hooked it up.

Now turn it on to a CD of familiar music. pull the rca's off the sub amp for now - we only want to listen to the HP amp.
If using in 4 ch - Adjust HP amp F&R levels so the 4 speakers are at same volume level and the amp is not distorting. Use your best judgment. If in 2 ch mode, adjust for no distortion at almost max volume.
Now turn off and hook up sub amp. Listening to music w/ good bass, at a decently loud volume, adjust sub amp level to where it sounds right. Once it sounds right, slowly adjust sub amp LP filter from around 50 to 80 and see where the woofers sound best. (probably around 60) Once the low freq is set, make note of it. If it is 60, set both HP filters on HP amp to between 80 and 100. If LP amp is 60, the HP amp will likely sound best at about 85. These are your basic settings. On the sub amp, the LF boost is like a bass control and should be dealt with VERY carefully - esp w/ free air subs. Want a little more punch to the bass? - play with that control a little at a time on various music. Going over 10 will likely result in a blown woofer.
Also, take your time - a little adjustment here and there make a big difference on how the speakers interact. If new speakers, set adjustments till they sound ok - don't try to dial it RIGHT in. Get sounding OK, then play the system as much as possible for a week or so, this lets the speakers break in. After which, they will sound better. Then adjust to suit your taste.

LP to HP you generally want a 20 to 25Hz spread to sound balanced.
If you get it out of wack - start over using same procedure.

Good luck -

Audiofn

Well I do not know how you wired the subs however I can not see why setting your slop to 24 Degrees would cause it to thump all of the sudden.

Let me try and tell you what those things do at any rate.

The SLOPE is used in conjunction with the cross over point. The steeper the slope (higher the number) the less it allows music from above the cross over point to go below the cross over point. Think if it like a dam. Your high freequencies are above the damn and the low frequencies are below it. The steeper the slope the less water that is allowed to go through.

The Cross over point works with the 1X and 10X switch. The cross over has a variable frequency. In the case of your amp it showes that you can set the frequencies from 50K-500K. If you set the switch from X1 to X10 then your settings will be from 500K-5000KHZ.

I have to make an assumption with your system because you did not tell us. I am going to assume that your head unit has RCA outputs for the Fronts, Rears, and Subs. Make sure that all your settings on the head unit are at 0. I am talking about bass, treble, gains anything like that.

For a starting point I would set the Sub amp up as fallows:
1) Pre Amp Output Section has no effect unless it goes to the other amp

2) Amp LP Filter: I like the sub filter to be set at 24 DB and the filter frequency to be set at about 85 to start with.

3) Infrasonic Filter turn off to start with.

4) Amplifier Input Section: You will probably want that set to low but again I do not know what voltage your head unit puts out tell we know what kind of head unit you have. Signal sensing can probably be off if you ran a wire for the remote.

I would set your front amp up as:

1) Rear Filter Controls (Runs the Babbs?): Frequency range to X1, Filter Slope to 12db, Cross over point to 75, Filter mode to HP

2) Rear Input Section: Input Voltage again probably low.

3) Front Filter Controls: Frequency range to X1, Filter Slope to 12db, Cross over point to 75, Filter mode to HP Input mode switch is set to 2ch if you only have 1 pair of RCA's going into the amp and 4ch if you have 2 pair of RCA's going into the amp

Now for the hardest part that takes years to figure out and I can guarantee the car guys do not understand. When you feel that you are missing something then you do not want to ADD what you are missing for sound you want to bring down what there is to much of. In other words if you feel that the subs are not strong enough, don't try and force them up, take the highs down for best sound. It is a lot harder then it sounds. I ussually start with my sub gains then bring up the highs to match. I have found that to be the easiest.

Hope that helps ya out some.

Jon

Audiofn

Hey are your 10" Subbs babbs like the rest of the speakers? If they are those are actually FULL RANGE and they will sound like doggie doo doo if you set them for bass only.

Jon

Audiofn

Well Bill and I are close to the same recommendations.... How do ya like that. Some slight variations on the way things are but that is mostly probably due to the fact that we really do not know how the system is wired. My only disagreement with him is the cross over settings. In cars we leave a gap in the cross over point because cars have a natural peak that ussually happens in the 60-120K range. Boats are so open that ussually does not happen. I have found that in fact due to the open nature of a boat those frequencies get lost. With your subs on the floor the bigest problem that I see is getting the bass up to your ear. That audio is going to be coupled hard to the floor....

US1 Fountain

iTrader: (1)

Subs are JL 10" free air subs 4 ohms. Brand new. Wired in parallel. both +'s to + of amp, same with -. So a 2 ohm load.
The 4 Babbs are 3 yrs old.
The 4 channel amp is wired as a 4 channel.

HU has 2 volt RCA outputs for FL, FR, RR, LR and a single sub RCA, So i have set the amps inputs on low. The sub RCA has a 'Y' cord connecting both the channels on the mono amp together per JL's instruction manual. 4 channel amp is not feed thru the mono amps preouts, just thru the HU. I think this is a better route because I'm using all 4 channels.

I'll try these settings and report back. Thanks!

US1 Fountain

iTrader: (1)

That's the exact reason I'm asking here vs the audio shop I bought from or from an audio forum. Both have very little knowledge of boat setups.

Audiofn

Like Bill said don't work on it for more then about 20-30 min then take a good long break. If you can listed to the same music on what ever the best stereo you have is so that you can re-actimate your ears to what the music is supposed to sound like. Your ears will start to trick the holly hell out of you after a very short time of listening to things all messed up. Check your wireing one last time as well. Make sure you are + to + and - to -. I just had my brother wire up my bathroom at my house and he put them out of phase and I was taking a shower about 10 min ago and was like WTF is wrong with the sound. Went up into the attick and wamo..... serves me right for having a computer programmer wire my speakers!!!!

You may want to go from low to high on your inputs but start with the low first.......

Wayniac

Narrowing the bandwidth increases gain with some amplifier designs.