JL 1000/1 Slash on 13w7
 

Alright, Ive been researching a lot about the best way to tune the amp. So many different opinions i went ahead and called JL Audio today. They told me how to tune it with a multi meter so I went and bought a decent one and got a test tune off itunes. It was a 50hz @ 0db test tune. I sat the amp at 54.7 AC. I connected the sub to the amp and it was ok. Nothing like what I was hoping for. I keep comparing it to my 2 12w6s which i thought it may be close. But it really isnt. Im wondering if thats just how it is. Its in a sealed box, that is supposedly built to spec. I build a ported box built to specs the other day and am hoping to drop the sub in there real soon. Any input on if a ported box will make a huge difference? Im doubting its very audible but im not sure, never have had a sealed box. Is anyone running this set up in there boat for a sub?

What you are discovering is that two 12s have more than a 50 percent increase in surface area as compared to a single 13.5....and, a W6 is easier to drive than a W7. You are also not making a direct comparison in the same environment. The idea of a W7 over a W6 is greater linear excursion (Xmax) but that takes considerably more power to realize the gain.
Try setting the gain at 100 Hz versus 50 Hz.
A bass-reflex enclosure as compared to sealed will be the equivalent of doubling your amplifier power in the meaty part of the bass. And, you will get one-third octave of deeper bass extension before reaching the half power point.
See the procees through to completion before making an assessment.

David
Earmark Marine

Ok David, so what you are saying is download a 100hz test tune and set the gain to 54.7 AC? I'll drop the sub in the new slot ported box tonight or tomorrow and see how it sounds than.

I was gonna say 80-90 Hz but a 100 Hz works as well...

Are you guys referring to a 100hz test tune and still set the sensitivity to 54.7 AC?

If you did the proper calculation and that's the number you got than yes @ 100 Hz like David suggested.. If it sounds a little top note heavy, drop it to 80hz or 90hz test tone...

ok, one last dumb question because ive never set an amp with a volt meter, always by ear. Is 100 hz or 80 hz (whichever sounds better) going to be louder (SPL) than the 50hz that it is set at now?

It will let more hertz thru so yeah there will be audible difference...

Bryce,
There is WAY more bass program material from 50 to 100 Hz then there is from 50 Hz and below. So of course it will be perceived as louder. Also, your woofer is already at half power at the crossover point.
But don't get confused over the frequency used for setting the gain and the crossover frequency. These are two very different issues.
As for setting the gain, establishing the the clipping threshold using a sine wave generator and a voltmeter is not the final step. It is just the first step in determining what is safe. But the test tone is often 5 dB hotter than the hottest CD recording and you can't set a woofer's gain that only reproduces 1.5 octaves independent of the fullrange coaxials/components that reproduce 8.5 octaves.
Getting your system dialed in is a lot more involved then what you'll get over the internet. At some point you may want to take the finished installation to a local pro for the final tuning. That may be the only way you will get your full investment.

David
Earmark Marine

jiggahertz???

Everytime I read a post from David I feel like Beavis. uhhhhhhh huhhh uuuuuhuhuhhh eeeerrrrr mmmmmm ok.

X2 Haha. I got my 3 pair xs-650s set where I want them, its just the slash has so many damn knobs! I got the bass eq off so pretty much the freq and input are the only 2 to tune. I tad more than impressed last night with it on my truck in my new ported box. I went ahead and turned the input up a little bit more because it sounded like the sub was still wanting more. It sounded great! Hopefully it'll sound just as good in the boat but since its an open environment, I'm sure it won't be nearly as loud. Thanks for everyone's input

Whatever you want to call it chief... Lol