Rumble vs. Pop

[Tomorrow]

Newbie here. I need help.
I have a JBL (yeah, I know, I know) speaker setup for 6.1. I listen to mostly tv/movies and some rock thru this system (all top of the line Panasonic electronics...yeah, again I know...).

JBL S312's
JBL J350 surrounds
JBL N26 back
JBL N-center
JBL S120PII sub (400W)

The problem is the sub. I get nothing but rumble, and lots of it, but no punch at all. No sharpness. Is this the nature of my setup, a faulty sub (it HAS been in the shop...it's remanufactured), or just the nature of JBL subs? I've moved it everywhere, but still no sharpness. Do I just want $2K performance out of a $400 sub? You'd think I'd get at least a 'bonk' now and then...but no. My neighbor's cheap 8" Onkyo is WAY sharper sounding.
Please help.

 

[Tomorrow]

.....and do you think a smaller (e.g. 8" sub) would add that tightness I'm missing? Thx.

 

[Sleestack]

This might be obvious advice... but, have you checked your crossover and speaker settings. I had similar complaints until I checked my speaker and corssover settings. The fronts were set to large and the crossover set too low. I changed the settings so that LFE was only directed to the subwoofer and raised the crossover to 100. It helped drastically... but only b/c my prior settings were totally wrong.

 

[Tomorrow]

I did check all the settings. The only thing that maybe is problematic is the receiver has a setting (large/small +/- 100 Hz) for the fronts that automatically selects itself for sub/out if the setting is 'small'. I set this to 'large' to accomodate the 45 Hz and up main speakers. I assume then that my low pass xover should be set to 45 on the sub. All other settings on the sub and receiver seem straightforward enough that even dummy me got it right.

I sure wish I had discovered this forum before I spent a ton on JBL speakers, by the way!!

RJ

 

[Tomorrow]

I gave the new settings a try...setting the fronts to 'small'. It did seem to clean up the sound, but there is still fairly sloppy, long-throw base sound. I'm getting more and more convinced this is either a bad speaker amp or JBL's just make lousy speakers.

I'm thinking about adding an 8" sub to the mix to see if I can get that tight, snapping bass I'm looking for.

Other ideas please?

 

[aarond]

try setting your fronts to small and turn the crossover on the sub all the way up to 150hz. play some good bass music and see what happens. if it sounds like a fart box then something is wrong with the sub. the s120 is not a terrible sub ,its a good $400.00, but its not a $2k sub.
aaron

 

[denverdoc]

I gave the new settings a try...setting the fronts to 'small'. It did seem to clean up the sound, but there is still fairly sloppy, long-throw base sound. I'm getting more and more convinced this is either a bad speaker amp or JBL's just make lousy speakers.

Other ideas please?

I don't know that JBL makes crappy speakers at all--the s26IIBE's I bought for 200 bucks/pair on the Harmon site are very good for the money, and I have owned several speakers that cost between 5 and 10k. Harmon Int'l spends a lot of money on research and the trickle down from the high end and pro sound outlets helps in the bang for buck dept for some of their lower priced gear, small Infinity's, JBL's, etc.

Before giving up on the sub, I would try to borrow another receiver if at all possible; if not have them hook it up where you purchased it to see if it sounds the same way. Or a quick test might be to run it from one of the other channels to see if the amp is messed up--run on large: altho it will be trying to play higher freq stuff, the bass should still sound good.
John

 

[krzywica]

This aughta help ya

Hey man I think these tech tips will help out a lot they sure did for me. I've got athena fs2 towers and a ksw12 sub. It took me a while to get it to sound just right, but thats the fun of H/T!
P.S. Here is some great info from an article on this site, if this cant help you then I dunno, call the doctor?

OK, I Get It But My Speakers Really Are LARGE!

For some, your main speakers may actually extend down to 30Hz or lower, especially if they include 10” or 12” side-firing low frequency drivers. The temptation will be to set these speakers to LARGE., The setting is there so there must be a place for its use, right? Actually, we recommend setting almost all speakers to SMALL, even if they are physically large floorstanding speakers. Here’s why: Even though those floorstanders have a low extension, they won’t necessarily go down to the lowest range of your subwoofer as linearly and free of compression (unless your main speakers have more piston area and box volume than your sub – but we won’t address that here) The problem with the LARGE setting is: the ultra low frequency information will not be heard if the speaker cannot reproduce it. Well if by some chance you were able to get your main speakers bass extension flat down to 20Hz, then adding the subwoofer on top of that would yield too much (up to 6dB) of bass output at the frequencies both are producing. Hence integration between the loudspeakers and subwoofer will be poor and the bass may be overpowering, sloppy and/or boomy.


http://www.audioholics.com/techtips/setup/loudspeakers/settingcrossoverLFE.php
http://www.audioholics.comtechtips/setup/loudspeakers/subwoofer_towers.php

 

[Tomorrow]

That was a GREAT summary. I get it, finally! (Duh - me.) I think I'll spend the rest of the weekend hiding behind speakers and making changes and trying to sort this boominess out.

I wonder if my wife will mind....... LOL.