JL Audio Fathom 13" Sub - Page 220

If you haven't already purchased the SMS-1, I would suggest you also look into the AntiMode 8033 which additionally corrects in the time domain (SMS does not, IIRC). I've read several reports of people preferring the AntiMode. It's also cheaper (last I checked), but cannot be manually tweaked or display results.
Anyway, I love what the 8033C does for my F112. Some say it's even better in combination with the ARO.

While I'm sure the 8033 is a very nice equalizer, it can't help with the *first* step, which is subwoofer placement. You need the visualization of the response for that. If I were to get the 8033, I would want to also get some kind of measurement software to use for sub placement and for verification of the benefits of the EQ. The SMS-1 offers that visualization, plus many more tweaking and optimizing features, (phase control in 15 degree increments, subsonic filters, multiple presets for different listening programs, etc.) You can see as well as hear the effects of using all these controls.

The SMS-1 may not set EQ filters in the time domain, but all equalization has an effect in the time domain. A room mode, resonance or standing wave is a time domain issue and when you reduce the levels of the resonances, they fade out faster in the time domain.

marky301067, does your receiver or pre/pro have Audyssey? If so, what version of Audyssey?

Craig

Yes, some valid points, but I think it's been shown (at least for some rooms, don't have links to the waterfalls) that the AntiMode is better equipped to deal with resonances. So I was simply suggesting that its worth looking into to see if it meets your needs. In my case, I have a single sub and only one sub placement option (and little desire to tweak), so it was the logical choice. DSpeaker also has a new product which is far more capable than either of these units, but at a premium of course.

FWIW, Kal from Stereophile has reviewed both in the same system (with the F113) and he clearly preferred the AntiMode (you can find many posts from him here and on other forums where he discusses the two units).

So if I understand correctly first is to find the right location for the subs!

Since i don't have equipment to measure I read that a method is to put the subwoofer at the listening position on a chair, then play some bass-heavy music and crawl around on the floor listening for where the bass is the most even.

Once I find the best place by ear, put the subwoofer there. One problem is this works only with smaller subs. Another problem is the key of the music affects what you hear. If the music has bass tones that align with the room's modes, this method can work pretty well. But if the music is in a key that doesn't excite the room modes, then other music that does excite the modes may sound unbalanced. A better by-ear method that uses bassy pink noise instead of music is described?

What do you suggest those JL AUDIO FATHOMS F113 are beasts I can only slide them with sliders forget lifting these babies!

??  Reviewed both?  Which both?  

Hi Kal,

I read that, and I scratched my head. Certainly I haven't read all of your reviews, (although I do read a lot of them), or all 27,000+ of your posts on AVS, and far fewer of them on other forums. Still, I don't ever remember you comparing the SMS-1 to the 8033 in a system with the F113. I guess it might have happened, but if you don't remember it either...

Craig

"Both" refers to the two EQs that were being discussed, and I'm sure I've seen you steer more than one person towards the 8033. In fact, a simple google search will reveal a number of such posts.

So, I was apparently recalling a discussion you were having on another forum where you were asked explicitly, "Have you directly compared the two EQ's in question?". To which you replied, "Not A/B but with the same equipment in the same room."

Read more: http://www.hometheatershack.com/forums/electronic-processing-equalization-devices/16577-velodyne-sms-1-antimode-8033-a.html#ixzz2S8tZJBVx

Ah.  

First, I have not been following this thread so I do not know the antecedants to the post.

Second, the statement you reference was about a comparison with a Paradigm Servo-15, not with an f113.

Thanks for the clarification.

Rule of thirds for sub placement what do you think of that, does it apply with two subs?

Which 'rule of thirds' are you thinking about? Haven't heard of the 'sub rule of 3rds before'...

Placing the sub 1/3 from either end of the walls.

Say your front wall [where your LCR speakers are located] is 12' wide you would place the sub 4' from the corner.

If you "long wall" [not that LCR/Screen wall] is 18' long would place the sub 6' from the front or 6' from the rear wall.

This is supposed to help with standwaves and harmonics.

I've seen many rules for subs and most vary in effectiveness. Even the mode calculators don't always show perfect results compared to measurement. The crawling test is a good way to go if you don't have anything to measure with, but it can be misleading depending on what you're listening to. I use the quick measure function in my Anthem D2V with a sub in the MLP. I then play sweep tones and walk around with the mic testing all the places I can actually put a sub in my room. I mark the places with the best response that I care about. Afterwards I switch the spots (subs in the marked areas and mic in MLP) and see if it is consistent. Most of the time it is close, but boundary gains do affect the measurement (sub in a chair doesn't have the boundary gains of sub close to or against a wall).

A modified crawl test...

I have two subs does' that still apply?

 

So my front wall is 18 feet wide and the long wall is 20 feet long  that means my front sub should be 6 feet away from side and 6.6 feet from the front wall?

 

And how about the rear sub or should I place both in the front?

Interesting Bob Hoddas places both subs in the front  in his room?

 

 

http://www.bobhodas.com/sound-advice-5.php#second

I guess that's the best position for his subs to be in that room.

It seems a lot of people with two subs place them in the front?

That's because it's aesthetically pleasing, not because it's the best for acoustics or sound quality. For room mode and resonance cancellation the subs should be as far apart or as randomly placed as possible. Having them symmetrical to the LP is almost NEVER the best, most optimal arrangement. It does look nice though.

Craig

Interesting, I don't like them in front, how about placing one on each side of where we sit?

How do you disable the crossover on the subwoofer so you are not clipping any bass information

^^ turn the knob for the frequency to 130 and the slope to off.

So if I do this then I set the crossover in the pre-pro yes!

Yes, bass management should be done in the pre-pro