Stereo system with low volume output....stumped!
 

JVC HU with 3 sets of 5V outputs

JL 300/4 slash amp
4) JL 7.7s @ 4 ohm
1) 10" JL sub off a JL 250/1 mono amp
The amps are matched to the speakers/sub RMS ratings

Using JL's recommendation for setting amp gains:
HU at 3/4 volume, all EQ settings at neutral,etc, set amp gains to their spec'd voltage output at amp speakers outputs using the 40Hz and 1Khz test tones CD, resuts in good clear sound, but volume is moderate at most when cranked. Far from loud.

With a buddy tuning by ear, HU turned up till distortion is heard, then backed down 1 step. 45/50 volume. Amp gains set same way. (This way ends up with gain controls set higher than JL's way) Volume is loud, but not a quality sound.

I then installed a Alpine HU, 3 sets of 4V outputs.
Tried JL's method, same results, great sound, but low volume output

This weekend I put my O'Scope on the amps speaker leads and was seeing no clipping from the JL tuning method, unless I bumped the gains up a notch, thinking it was set correctly using a the DVM method, but I wanted to use the OScope from scratch. SoI started back with the HU and set max volume at the RCA outs using the scope and increasing volume to right before clipping is detected, but a full volume no clipping was appearing. So I just used 33/35 for max volume. Then Amp gains also set using the OScope to right before clipping. And once again, I get great sound, but the volume is not there!

I'm at a loss on way I can't get the volume w/o over driving the amps.
Both HU's show same results, eliminating HU issues

Any ideas?

You could use more amp for sure. The JL are rated at 100watts rms and will take more wit clean power. You would be much better off with off with 4 channel 600watt digital amp.

Not sure if thats your complete issue, but the amps are holding you back.

I have a very similar setup, Pioneer HU with a JL 300/4 and 2 JL 6x9, and 2 JL 6.5's, along with a JL 500 with 2 JL 12" subs. My speakers are mounted too low for best sound but it's still very loud. It's the only thing louder than my engine without mufflers. I'd contact JL, I had an amp go bad and sent it in for repair and they were very reasonable. What db are you getting? The 7.7's are supposed to be very efficient, I am considering adding a pair of them in a better location for better sound at speed. Next time I go up to the lake house I can check mine to see if loud means the same to both of us.

I believe your methods are beyond the quality of your equipment..that's a compliment to both by the way. Turn you HU gain full up and preamp should not clip nor break up it is not a amp. Then adjust the gains on the amp's accordingly one will never get the right balance or perfect balance with preset gains...music is far to dynamic than that.. Speaking of dynamic's is there a dynamic compression filter on the hu..that could cause such a imbalance does the hu have one? below is a simple understnading

http://documentation.apple.com/en/co...4%26tasks=true

Just for bench talk here, considering just the JL method for gain adjustment since it's a straight forward easy to relate to numbers tuning thing...........

For chits and grins today after thinking about the amp being undersized as Griff suggests, I looked at both my 300/4 vs the JL HD600/4 amp setup specs. Using the JL method of using a DVM, the 600/4 uses higher voltage as the set point, over my 300/4. And since speaker volume is controlled by voltage, this makes me believe I am in fact short on power since when I do increase my gain (voltage), the speakers do play louder, though distortion appears when turned too high, to where the sine wave clips. So I assume ????? a larger amp provides cleaner power at higher gains (voltage) levels, resulting in crisper sound at higher volume. I do understand that amp gains aren't volume controls, but a means to match the amp to the HU's output signals.
I think the JL method can get one real close in the ball park, then tune by ear if one can hear minute changes.
At least this sounds good, good enough to justify buying the HD 600/4 amp :)

Thanks for the link and the replies

My full volume loud is good for put puting around with a boat load of partiers, or when at the dock listening to tunes, but not loud enough to hear when running the boat (cruiser=not loud exhaust) at speeds to overcome wind noise or when at the dock when we are all wound up wanting to crank the party up.

I have never had any luck using the voltage method JL suggests, I always have to put the amp gains much higher to get proper volume. I put my head unit volume at 3/4 of full and turn up the amp gains until I start to hear some distortion and then back them off a little. You just have to sit there listening to a variety of music until you feel the settings are correct.

You can always give JL a call they have good tech support.

That doesn't sound right to me, mine is so load that I can drown out the shore partys when I cruise down the river. Although I don't play the tunes when I'm cruising across the lakes (80mph). Actually it's loud enough that I can't hear my wife yelling at me to turn it down, she has to use sign language.

JL's method is more precise and conservative, just like their equipment. Tuning with voltage and Oscope will yield a clean, conservative sound.
Most ear tuning will not hear distortion until it is significant, thus the instructions to back off the gain once distortion is detected.
Curious what the gain levels were between the two methods?

Using a CD should be a level volume and eliminate the fluxuation people often experience with mp3's.

Agree the speakers are underpowered if maximum volume is expected. Again, JL conservatively rates their equipment for maximum tone and life expectancy but they can easily handle more. Notice in the specs, recommended power is between 40-175w per channel with 100 rms CONTINUOUS.
http://www.jlaudio.com/m770-ccx-sg-t...-systems-91754

600.4 will be a much better choice for higher volume and given how proper and conservative you are setting up, will be no problem.
I doubt you will find the highs to be much louder since tweets are naturally efficient but the mids will be noticeably fuller and louder.

Depending on music listening, I predict your next thread will be "Upgrading Sub? This single free air 10" is not enough" :whistle:

Actually I'm using the JL infinite baffle sub. Though I didn't see any improvement over my free air I initially used 1st. Kicking around installing both my free air subs in place of the current single one. Or trying to get a larger sub to fit where the 10" is now. Gotta check the cu ft area I'm working with. But I think a larger sub will be better than 2 smaller ones.
Thanks