JL Audio Fathom 13" Sub - Page 98

I'm not sure this will solve your problem, but I would raise the output on the receiver to about 0 and lower the gain on the sub for starters.

I read at SVS site and some others as well that we should keep the sub level @ - 5 ( on a scale of -10 to +10) so that the receiver would send the cleanest distortion free signal to the sub. I initially set it at -6.5 and the gain on the sub to 12 O'Clock and calibrate using SPL to arrive at my current level. My SPL now read 77 db and sometimes I up the level on the receiver to -3.0 to give ti some boost. Still this sub lacks impact.

How big is your room overall and is the room open to the rest of the house? Also, how far do you sit from the sub?

Yes. After extensive placement experiment, the current spot turns out to be the best possible spot for both subs.

Sorry, I had edited my above post and changed my question.

My room is 20 x 17 x 8 that is open to a small foyer,that leads to the stairway. I sit 11.5 ft from the sub.

You should be able to get decent volume in that area. Many of us when we calibrate, run the subs a little "hot" by 2 or 3 db. Have you tried that? I'd also be interested in some of your receiver settings like speaker size and crossover. Have you tried adjusting the phase setting on the sub?

The sub is set up 2 db hotter. I even crack it up by 3 db more when I watch a movie. Speaker size is set to small, XO is @ 80 Hz, LFP also @ 80 and phase is set to 0.

Alex,

- leave the ARO off. I find EQ'ing the sub yields a flat response but often, it removes some of the mid bass punch we are used to hearing. I use an SMS-1 and I found that after EQ'ing the sub for flat response, it removed much of the wow factor I was used to hearing. I ended up moving my sub to behind my seating area (based on what Hsu owners recommended) that gave me the punch I needed because I was just sitting too far away from the sub.

I'm not sure what else you can do, the sub should be able to give you good wow factor once set up correctly. Play something that has sustained bass like the airplane crash scene in Flight of the Phoenix if you want to test it out.



If all else fails, then the JL is not going to do it for you, then I hope you can return it and try a different sub.

Your receiver settings seem fine, but I would check the phase. Use a 80 hz test tone and set the phase to where it gives you maximum SPL. You need to make sure you are not getting cancellation with your mains in the area of your 80hz crossover. That will cause you lose punch.

warpdrive, are you suggesting I should run it higher than 80 db for movies? I never tried leaving the ARO off before and I will try it now. I would like to keep the Audyssey to "ON" on the Onkyo, as it flattens the overly exaggerated bass I get from my speakers.

That's how I determined to leave the phase to on. How do I check that I am not getting a cancellation at the @ XO?

Typically, you would run a test tone that matches your crossover frequency (80hz) and set the phase to the position that gives you maximum output.

Are you saying not to use the ARO or the SMS-1?

Or are you saying to use the SMS-1, but not the ARO?

Yeah, that is waht I did that to get to the 0 setting on the phase.

Ok, a quick check on the net gives this method to check for crossover setting:


"STEP #6:
FINAL LEVEL ADJUSTMENT: One last time, adjust the subwoofer level to the
mains exactly as described in step #4 above. Now, use your Pre/Pro or Receiver
pink noise level calibration tones or one of the calibration discs, if that's what you
use, to lastly check the levels of all speakers and subwoofer.
There have been many comments about how the RS meter is not accurate in the
low frequency region, and is also said to differ from meter to meter.
Here is a possible method, using the RS meter, to adjust the subwoofer level to
that of the satellites.
Again, we're assuming that you have already calibrated your satellites to
the same level before this point in time, and we've done steps 1-5 of the
subwoofer setup.
Set your Pre/Pro or Receiver mode to 5 STEREO and shut your subwoofer off.
Set your master volume to approximately -10 dB from reference, or, so that a test
tone (from your test tone disc) will read in the neighborhood of 80-90 dB.
Play an 80 Hz tone from your test tone disc (it should play through all 5 satellites
equally).
Note the reading.
Now, shut your satellites off and turn the subwoofer on and play the same tone
through your sub only.
Adjust the subwoofer level to the same reading that you got when playing just
the satellites.
A crossover only works correctly if the speakers being crossed over together play
exactly the same volume at the crossover point. In adjusting the subwoofer level
with this method, the accuracy of the RS meter becomes irrelevant because the
only thing that matters is that the subwoofer and the mains are at the same level
at 80 Hz (the crossover point).
The meter will read the same at 80 Hz every time. Whether or not it's an accurate
reading, it will level the sub to the mains at the crossover point by this method,
accurately. Since the satellites are already calibrated, the subwoofer will
automatically be exactly at that level at 80 Hz.
I have personally done this test many times and found the subwoofer level to be
within 1 dB of 75 dB (which is the level I calibrate to when using the Pre/Pro
calibration tones), and you can quickly check this method against your calibration
rumble tone method to see if it's of any value in your case. My opinion is that, if
this method is close the the rumble calibration tone, then keep the subwoofer
volume set to the level arrived at by the 80 Hz test tone method.
You can adjust the level of your subwoofer up or down for different source
playback, at will. There is no rule that dictates what level you have to play a
subwoofer at. BUT, you now have the correct settings that will tell you where your
subwoofer should be, in your room, with your associated hardware, as a
reference.
It's a good idea to write these settings down (Pre/Pro or Receiver sub level,
phase, placement position and subwoofer amplifier gain), as you'll forget them
shortly after you change any of them, and it's a good idea to reset them to these
reference settings every so often to see what havoc you may have wrought over
time.
You are now ready to play your system and evaluate the results of your setup
labors."



Going to try this out now....

The next step would be to plot the overall frequency response in the bass range. This can be a bit tideous, but if it seems like something is missing, this it what can find it for you. It can be done manually with multiple test tones or it can be done with the help of a computer using REW software. Are you familiar with that?

I did that manually but only from 20 HZ to 140 Hz. It' almost flat except I get a dip to 70 db @ 100 Hz and another dip to 70 db @ 140 Hz.

Both accomplish the same thing ultimately, so there is no sense using both at the same time if you have both. If you have an SMS-1, you don't need ARO or any other room compensation circuit because the SMS does what the ARO can do but more.

The ARO is used to give you the flattest possible reponse at one or more listening positions by targetting and eliminating one room peak. The SMS is a full EQ which can do that but also allows you to tailor your response just the way you like it (and you can eliminate multiple peaks and choose a "house curve")

Through my trials withe SMS1 I found that usually a slightly exaggerated mid bass hump around 30-40Hz is what gave me that gut shaking feeling. Once I eliminated that peak with EQ, the sub lost that wow factor (but sounding better with music). So I was suggesting to Alex that he try the sub without ARO to see if the wow factor comes back. If so, then ARO is too aggressive in removing the peaks

Don't give up yet, and don't be angry. I hope you don't feel that someone here has tricked you into buying the JL. You know the sub is capable of some high output based on the ARO test. I would definitely disable the ARO for now since it's possible it's attenuating the bass to much. I would then double check all of your settings in your receiver and dvd player. What movies have you tried watching? Try watching the Darla Tapping scene from Finding Nemo. That one shook my whole apartment with my F112.

btw, which HSU did you have? If you had one of the larger HSUs like the 3.3 or HO then you can't expect a huge increase in output from the F112. The 3.3 and HO have some pretty respectable output especially down low. After all, the F112 is less than half the size of the HO. One of the big differences I found between the two, however, was the articulation in the bass and the ability of the JL to completely disappear with music.

xcjago, I don't feel like I was tricked into buying the F112 at all. And "angry" was not the right word to use, I should have said "frustrated" instead. I trust the collective opinion of the members of this forum and I have not been disappointed with my previous purchases based on forum feedback expect for a couple of speaker brands that didn't live up to the hype, in my opinion.
I have the smaller HSU, the SFT-2 which is a 10" sub. The F112 is quite good with music. I see no fault there, just miss the slam I was used to with the HSU. For e.g., the gun shot scene in Open Range sounds so real with the HSU but can't get the same effect from the F112. I was actually expecting a far greater performance from the f112. I expected it to take me there... put me right in the middle of the action. I will play around with the settings again and see where I have gone wrong.

Something is definitely not right. The F112 and the STF-2 are in totally different leagues.

Alex Solomon

I may have missed it, but how is your sub connected? I used the RCA (unbalanced) on my f113, and was happy, but not blown away. Then I saw some posts that suggested that some subs were not correctly summing left and right inputs if using a single connection. Pulled out a "Y" connector, fed the signal to both L&R, BINGO!

Sounded much better, confirmed I had gained 3 db with RS meter. I've been backing off on levels ever since (seems like I would just need to lower my sub outut by 3 db ont the Lex, but no).

Give this a try if that's how you're set up.

Now you see why I got frustrated. I expected a night and day difference between these two subs. It's has to be a setup issue but I did all I could. I am going to call JL sometime next week.

Is this a known issue with the Fathoms? I am using a single RCA connection form receiver to sub.

*edit*

oooops, wrong thread

If you have the RECEIVER doing bass management, AND you have the filter on the sub on, then you are "double filtering". Turn the LP Filter switch on the sub off.
I'm surprised no one else caught this...

Barry

ALL subs that are not toys are calibrated to use ONE mono input from a bass managed receiver going into ONE of the RCA inputs. That's why there is a MONO SUB OUT on the receiver.

By Y'ing the cable you are doing nothing more than turning the bass up 6dB, (not 3dB). The 2nd RCA connector is there in case you are using a setup with a stereo (i.e. 2-channel) system.

In fact every sub that has multiple inputs such as 2 x RCA's and 2 x 3-PIN connectors (and even 2 x speaker connections) sum all of these together internally into mono anyway.
With most receivers, you should notice that if all the levels are set at "0" AND the sub calibration is at its "0" or reference that you should get the same 75 dB reference noise nearfield from the sub.

Of course all those reference levels are useful as a starting point and at the very least you have something to return to when you get hopelessly confused...and want to start over.

To further clarify, the "real" THX and Dolby reference level is 85dB, but somewhere about 100 campfire stories ago, some receiver mfg decided that 85dB pink noise frightened people (and pets...). The internal levels and all that that entails (0VU, digital headroom, analog headroom, disc reference level, etc) are still really set at 85.

Some receivers, like the Anthems are smart (and clever) enough to allow you to set the "0" refence either where it belongs or somewhere where "you" like it, to assist you with meter readings, for example.

Barry

Nice catch. If that's the case the Alex has the LPF turned on for the sub, then he is cascading filters and likely loosing output in the 40-80 Hz range.

LP Filter is set to off from the beginning. LP Freq. is @ 80 Hz but that won't matter since I have the LPG set to off. ELF trim is set to "0". I am going to check all my settings again and run the ARI and audyssey again.
BTW, if I was losing output between 40-80 Hz then when I run sine waves would I notice that, right? When I run sine waves from 20-90 Hz the SPL read between 79-81 at all levels. I did check the XO and the sub and the speaker are playing exactly at the same volume at the XO point which is 80Hz.