JL Audio Fathom f110v2 powered subwoofer Measurements

Sidebar 3: Measurements

Before JL's Digital Automatic Room Optimization, D.A.R.O., (fig.1, dotted red trace), a large, broad hump at 32Hz and two nulls at 66Hz and 84Hz dominate the sub-100Hz range. After D.A.R.O. (solid blue trace), the 32Hz hump is mitigated and the range below the nulls is flattened and extended. Note that, as positioned, the single subwoofer cannot significantly reduce the two main nulls. Note the smooth low-frequency extension to below 15Hz, impressive for a single 10" driver.

720jl.fig1

Fig.1 In-room low-frequency response of single JL Audio f110v2 subwoofer before (dotted red trace) and after (solid blue trace) running D.A.R.O.

The single f110v2 plot in fig.2 (dotted red trace) is the same as in fig.1. Because three subwoofers (solid blue trace) can energize different modes to different extents by feeding in energy from different locations, this arrangement, in contrast to the single-sub arrangement, is able to mitigate the two main nulls. Also note the further flattening at the lowest frequencies.—Kalman Rubinson

720jl.fig2

Fig.2 In-room low-frequency response of a single JL Audio f110v2 subwoofer (dotted red trace) vs three of the same subs (solid blue trace), positioned as described in the text, both with D.A.R.O. equalization.

COMPANY INFO
JL Audio
10369 N. Commerce Parkway
Miramar, FL 33025-3921
(954) 443-1100
ARTICLE CONTENTS

COMMENTS
Bogolu Haranath's picture

I understand that, KR his going to be reviewing the new NAD M33 for a future issue of Stereophile ..... May be KR could use the built-in Dirac Live of M33, and give us his opinion about, whether that Dirac Live can modify/extend/enhance the bass frequencies of his Revel Studio2s, without the assistance of the separate subwoofers :-) .......

Kal Rubinson's picture

Wait for it..........................

Bogolu Haranath's picture

Fantastic ..... Looking forward to reading that review :-) ......

Ortofan's picture

... eliminate the two-sub setup from consideration?

Did you ever consider trying two subs, with each placed midway along the side walls?
Or, two subs, with one in the front and one in the rear, in diagonally opposite corners?

https://www.aperionaudio.com/blogs/aperion-audio-blog/dual-subwoofer-placement-for-your-home

Jack L's picture
Jack L's picture

...... along the side walls?" quoted Ortofan.

Take it easy. This is no rocket science.

I've installed 3 active subs for my stereo tube amp system at home years back: L, R & L+R. They work like a chime as they bring back so so much (mid-bass, DEEP deep bass) music missed from the original recordings, which I would have never known without those subs.

So why 3 subs: L, R & L+R channels? Simply most concert halls are equipped with mim 3 overhead microphones: L, R & L+R to capture the overall acoustic perspectives of the performances.

My L sub is seated 2 feet behind the L standspeakers, about 6 inches from the back wall, likewise for my R sub. The L+R sub is placed exactly midway bewtween my L & R front speakers.

I hooked up the 3 subs direct to my design/built tube phono-pramp WIHOUT any costly complex cross-over electronics, using the low-cut network already built in each sub.

Simplicity provide better music.

Room acoustic 'compensation' electronics? I don't need it.

Trust my ears-on & hands-on experience on subs.

Listening is believing

Jack L

Bogolu Haranath's picture

Jack, you are describing 2-channel system ..... KR is talking about multi-channel system in an odd shaped listening room with non-moveable furniture :-) .......

Jack L's picture

..... listening room with non-moveable furniture" quoted B Haranath.

Hi

First off, I am NO movie fan but stereo audio only lover. So multi-channel sound systems for movies is not my cup of tea (again, no coffee for me as well).

IMO, multi-channel sonics is a huge MESS of synthesized sound, often ear deafening, failing to produce the right soudstaging & imaging, even without any subwoofers. So why worry about precision placement of subs ??????

I would NOT waste time & my hard-earned cash on unreal synthesized sounds!!!!!

Jack L

Bogolu Haranath's picture

KR listens to surround sound audio for music, not home theater sound effects :-) .......

Kal Rubinson's picture
Quote:

I would NOT waste time & my hard-earned cash on unreal synthesized sounds!!!!!

Nor would I! My sources are discrete multichannel recordings wherein the various channels reproduce the sound of the performers and the performance space in a way that stereo cannot. If it is not recorded this way, I revert to good stereo recordings played in stereo which better than not bad. This is not HT as there is no display and no video. (I guess you don't read what I write, so.......................?)

Jack L's picture

Hi

I would be interested in how "discrete" are the signals picked up by various channel microphones are processed. Mix-down & then regeneration is not longer 'discrete' at all !!!

Jack L

Kal Rubinson's picture

I have many which are simply 5 mics into a 5.0 package. In fact, I particularly relish the ones that are direct mic feeds prior to any mastering. Of course, there are others which use "spot" microphones and those are subtly mixed into the main 5 channels.

Jack L's picture

Hi

So the positioning of the 5-channel playback loudspeakers would be very very critical. Otherwise, it is hard to reproduce correcly the spatial ambiance of the original recording venue.

Jack L

Bogolu Haranath's picture

Jack, you are also taking about 2-channel mix down of 'Decca Tree' 3-microphone placement :-) .......

Kal Rubinson's picture

Why did you eliminate the two-sub setup from consideration?

I tried the two possibilities for 2 subs in this room and both were unsatisfactory.

Did you ever consider trying two subs, with each placed midway along the side walls?

Not possible as there is a couch on one side wall and a large cabinet on the other.

Or, two subs, with one in the front and one in the rear, in diagonally opposite corners?

The one diagonal where this was possible (note this room is one leg of an L-shaped space) resulted in an audibly unbalanced performance without and with EQ.

Deandome's picture

I know it's gonna take some time, but we really need to weed out the word 'slave' in discussions about audio components (and flash photography, industrial controls,etc.).

I include myself in this 'we', BTW. This isn't a criticism of KR or JLA; these usages have been around a long time...though I've long thought it a bit jarring as whenever I've seen it.

I don't think this merits much debate or discussion; I'm not here to start a flame war.

It's not political...it's just time.

Jim Austin's picture

The proper use of "master" and "slave" in the context of audio will continue to be allowed here, with posters being encouraged to be courteous of the feelings of others--not only those offended by the term but also those of good character and liberal views (in the broader sense, not the political one) who innocently use long-accepted technical terminology. Perhaps we can all work on making this adjustment--I intend to do so in the magazine--but no one should be condemned for the occasional slip.

While it probably does merit discussion and debate, this is neither the time nor the place.

Jim Austin, Editor
Stereophile

Deandome's picture

Thanks. I hoped to better emphasize this is/was a general point, not a condemnation of Kal or this publication*, which I have silently cherished for decades (*in my mind, it's still a curiously-sized, perfect-bound joy!).

Jim Austin's picture
I understood, and did not intend my response as a criticism. However, I thought it appropriate to set and express a policy for Stereophile. Best Wishes, Jim Austin, Editor Stereophile
supamark's picture

we take a cue from biology and use mother/daughter (like in cellular biology) or the more generic parent/child. It shows a hierarchical relationship, would be understood as well as current terminology, and is much less offensive to pretty much every rational person. It has the added bonus (to me at least) of being rooted in scientific terminology.

Jim Austin's picture

A lot of people have been working on replacing "master/slave". There are some good alternatives.

Jim Austin, Editor
Stereophile

Kal Rubinson's picture

I think parent/child is not a good analogy in the present case since the master and slave subs are fundamentally co-equal but are distinguished by one acting as the controller while the other is the controlled. We need other and better, I think.

Jim Austin's picture
Editor-Writer? :-)
Bogolu Haranath's picture

Primary - Secondary ? :-) ........

Bogolu Haranath's picture

Husband and wife or, wife and husband ........ Depending upon whoever is the controller and, whoever is the controlled :-) .......

Bogolu Haranath's picture

Gladys Knight & the Pips .....
Echo & the Bunnymen :-) ......

nirodha's picture

The only one that has the right to have an issue with the term "slave" is the sub itself.

Ortofan's picture

... master and grasshopper to be less objectionable?

dcolak's picture

Let's also stop calling killers killers, dictators dictators, rapists rapists etc.

New-speak is popular these days.

tonykaz's picture

it's not critical, is it?

A person could live a happy life with no more capability than a pair of LS3/5a and a NAD 3020 original ( the latest Digital version is not so dam good ).

Properly pressurizing a full Large Room of 4,000 cubic feet requires engineering, measurement tools and unique gear. Who has access to that kind of thing? i.e. Bob Katz writes about setting up his latest Florida Mastering DynAudio System and B&O seem to accomplish it with their latest BIG fully digitized Class D Masterpiece Loudspeaker system.

I've experienced seamless Full Range Systems using Subwoofers, turn off the AC Power to the Sub and the magic is gone, Poof ! A person can't quite notice the Sub while its in the system doing it's work.

But...

Subs not set properly cause problems.

My Sennheiser HD 600 series headphones and Schiit Amplifiers reproduce the ultra low frequency parts of the Bombay Dub Orchestra recordings, most loudspeakers ( that I've ever heard ) can't do so. ( vinyl can't go low enough either, its a digital capability ). Bob Katz can hear it with his engineered gear and incredible Mastering System.

Deep bass capability is worth owning and worth the commitment, it's one of the last steps in being an Audiophile.

Prepare for complaints from family and neighbors. ( maybe even a call from your wife's Attorney ( a fellow audiophile, in my case ).

Tony in Venice

Ortofan's picture

... for LS3/5a users.

https://www.grahamaudio.co.uk/products/sub3/

https://www.hifi-advice.com/blog/review/loudspeaker-reviews/loudspeakers-passive-reviews/graham-audio-ls3-5-and-ls3-5a-with-sub3-part2/

tonykaz's picture

Hmm, this speaks to JA2 say'n how big our Audiophile Tent is.

LS3/5a to Diavelet and Beolab.

I'd be calling for Scotty to beam us up but we're already well into the 21st Century of advancements and I don't know what more we could be asking for.

Tony in Venice

Bogolu Haranath's picture

LS3/5a + subwoofer makes it the 'Voice of the Universe' (VOTU) :-) ........

Kal Rubinson's picture

"it's not critical, is it?"

It is to me because the music I listen to most requires it in order that it have a natural balance. Can't have an orchestra without the double basses.

tonykaz's picture

And this little Sub is only a $4 Grand addition.

Any decent Phono Cartridge ( that probably struggles with Basses ) will cost two or three times as much yet have a lifespan of 6 months or less.

Are your neighbours complaining?

Is your frequency response graph only showing 50ish SPL?

What the hell, $4,000 seems cheap for filling out the System's performance envelope of usefulness.

Tony in Venice

ps. Now, with the new Subwooofer, is your home system the equal of Carnage Hall. ?

Kal Rubinson's picture

Are your neighbours complaining?

They have not complained in many years and, then, the only complaint was when I pushed a (now nameless) speaker that was lacking in the bass in a fruitless effort to get some kick out of it.

I generally try to be a good neighbor.

Bogolu Haranath's picture

JL Audio makes Gotham subwoofers ...... Four or more of those could make the listening room equal to the rocket launch pad at the Kennedy Space Center :-) .....

krahbeknudsen's picture

This is an interesting subject. When I sit in a symphony hall often I hear very little deep bass compared to recordings.
Indeed, the Helmholtz (lowest)resonance (A0) of a typical double bass body is 65 Hz, while a low E (deepest string) is around 42 Hz. This is true for the whole violin family. The sound of deepest string is the result of psychoacoustics because the instrument has no resonance there. We think we hear deep bass but it is not there.

Kal Rubinson's picture

Indeed, it is not so much frequency extension since the main speakers can go low enough for me. The major issue is that the main speakers are situated and oriented for soundstage/imaging but not for optimal bass. Adding one or more subs at room boundaries and with EQ serves to make the entire <100Hz range cleaner and more effortless.

tonykaz's picture

Right there is the essence of your entire review. ( I think )

Pro people doing live gigs would call it bass reinforcement, done with bass bins which are horns about 3 feet wide x 4 feet tall x 3 feet deep capable of staggering SPLs and controllable by the sound guy running the boards.

Powered Subs make life easier for the system's amplification.

I've fallen in love with the Meridian Actives since the mid 1980s when I was importing them. Now, Active loudspeakers are the only things that make sense. Maybe I'm not a tweaky Audiophile

Tony in Venice

Bogolu Haranath's picture

DSP controlled active speakers like the D&D 8c, reviewed by KR and JA1, are the future ..... In the near future they will also incorporate larger diameter or multiple woofers :-) .......

Bogolu Haranath's picture

It is possible that, the Dirac Live could do that, below 100 Hz, cleaner and more effortless from the main speakers, without the help from separate subwoofers :-) ........

Kal Rubinson's picture

Not so far. The constraint is that, currently, DL only EQ's each speaker independently. DL3 with its advanced "Bass Control" option, not available for the M33 at the time of the review, will enable the use of each of the 5 full-range speakers as "virtual" speakers + subs with the low ends integrated.

Bogolu Haranath's picture

You (KR) could do a follow-up review of DL3, when it becomes available :-) ......

Bogolu Haranath's picture

A total of four 8" woofers in the Studio2s is almost equivalent to a single 15" woofer in bass output ..... A total of six 8" woofers in Salon2s or F328Bes is almost equivalent to a single 18" woofer :-) .......

Kal Rubinson's picture

That presumes:
1. That they are tuned and equipotent in the sub range.
2. That they are placed where a sub will do the most good.

Bogolu Haranath's picture

When reviewing the Devialet Expert Pro, JA2 said that, the Revel Salon2 woofers made his windows rattle more than 20 feet away :-) ........

Kal Rubinson's picture

Rattle is easy. Music is hard.

Bogolu Haranath's picture

You (KR) may be familiar with this, TJN wrote a review of the NAD M17 V2 surround sound pre-amp processor with built-in Dirac Live for S&V magazine :-) ......

Kal Rubinson's picture

I did, too.
https://www.stereophile.com/content/music-round-95-wolf-nad-page-2

Bogolu Haranath's picture

So, I presume you (KR) bought a new plasma display :-) .......

Kal Rubinson's picture

OLED

Bogolu Haranath's picture

Hope it is 8K, Dolby Vision, HDR, IMAX Enhanced :-) .....

dc_bruce's picture

I think they have two purposes. One is to achieve in-room bass response down to 20 Hz; and the other is to provide bass power at higher than 20 hz bass frequencies. While many so-called "full range" speakers claim bass response to 40 or even 30 Hz, their ability to do so at higher than modest output levels without significant harmonic distortion is limited. Even a fairly modest subwoofer can deliver a robust, largely undistorted output at the lowest musical bass fundamental of 42 Hz. (Yes, I know pipe organs and synthesizers can, and do, go lower.)

One thing, you didn't mention in your review Kal is whether these subs provide the sense of "spaciousness" or "hall sound" that others report from larger subs that feature robust 20 Hz extension. I recall one review of a smaller sub that, in so many words, said that the sub under test provided nominal 20 Hz extension in a "yes, but" sort of way that failed to give that sense of spaciousness yielded by larger subs that also provided 20 Hz extension.

Your graphs of the degree of room correction provided by multiple subs was very enlightening and certainly an incentive for people to consider 2 or 3 smaller, cheaper subs as opposed to one behemoth. It also shows (as if this needs to be proved any more) that a good parametric equalizer is essential if the sub is to provide a net sonic benefit to the system rather than be just a boomer.

Fishman1234's picture
Glotz's picture

And with smart placement (which took 5 minutes!), they (REL T-5i's) integrate beautifully into MG-1.7i's with stereo coherence, smoothness and grace.

At $1200, the pair provides stereo bass support, maintains the original sound of my amp, increases the back-hall depth perspective, image stability and widens the stage perspective without bloat or over-push. John Hunter of REL has some salient things to say about stereo sub operation over single sub output referring to this increase in back-hall detail recovery.

It also keeps the investment rational for more audiophiles, as the investment is half that of my main speakers. For apartment dwellers, it also provides excellent extension to 30Hz (but no deeper really) and this keeps the neighbors at bay, even with highish SPL's at night.

At almost $2000 for pair of REL T-7i's, they are probably even a better value, but they also have forward-firing woofers which may complicate (any) speaker integration attempt, or over-power smaller rooms with the addition of larger passive radiators.

I don't mean to take anything away from JL Audio. I always enjoy Kal's writing. This is just another way to skin a cat and it might be helpful to others to add that 2nd, mirrored sub or investigate REL's different approach.

MFK's picture

If you have the space and don't have to worry about neighbours, at least one subwoofer is a no-brainer. Why not? I don't own Harbeth and am not advocating for Alan Shaw's approach but his ideas are always interesting. Check out the sound samples with various brickwall filters.
https://www.harbeth.co.uk/usergroup/threads/bass-response-how-deep-should-my-speakers-go-for-a-lifelike-sound-at-home.1659/

drh3b's picture

I think it would be interesting if you would audition Rythmik or other ID subwoofers. I know you are aware of these brands as you are on AVSforum. :)

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