[James Romeyn]

System employs three RM30C in front, two (Dipole) Surround SE's in the rear (misnamed, actually bipolar), one 2004 Sunfire True Subwoofer EQ Signature ($2200 MSRP, 13" cube, about 65lbs, 16-100Hz).  The sub has 2700WRMS, fully automated EQ covering the entire range of output (EQ effect continuously variable from 0-100%), a calibration microphone, crossover continuously variable from 30Hz (third order)-100Hz (fourth order), & continuously variable phase from 0-180 degrees.  The EQ technology was new for 2004 & earned Sunfire a top ten finish for 2004 Best of CES honors (won by Meridian's processor circa $9000 MSRP).   The input sums (L+R) + (L-R), eliminating the losses caused by out-of-phase stereo input signals.  The tiny sub's 116dB output (w/room gain) is achieved via its super-high powered amp driving a super-long throw active woofer.  The extra high mass passive radiator achieves the 16Hz cutoff.  

In researching before purchase, Sunfire dealers & others admitted that setting the crossover too high (85Hz range) could make the earlier non-EQ's models sound slow & a-musical.  I had minimum experience hearing the earlier non-EQ models.  An engineer friend has one but it was hard to analyze the sound at his place because his large Carver Signature Ribbons (four open-air 12s per side) could use more breathing space.  I prefer the sound at his place sans subs.  

I've had the sub for at least a few months.  It exceeds anything I've dreamed of in every parameter: value, performance, cosmetics (highly lacquered dark cherry veneer), convenience, & ease of setup/use.  I recommend it unequivocally.  My room simply has no space for more clutter than this little 13 cube.  A customer who purchased one for his seven-piece VMPS RM30-centered system has a similar evaluation.    

Which Mode Are You In?

My room has two bass modes, a terrible one around 30Hz & a slightly less bad one around 80Hz.  Someone posted that, if used with a sub, the RM30Ms beat the RM30Cs because the Cs bass cutoff is too high.  That may be true with a non-EQ'd sub, but not with the Sunfire's automated EQ, & not used in this room.  

The EQ in this sub changes the picture.  Any sub may sound too slow & a-musical beyond a certain crossover frequency.  If that happens there is no alternative but to lower the crossover.  If a gap in output develops between the sub & main L/R speakers, you must either get different main speakers &/or a different sub (unless an environmental change can fill in the gap).

I first setup the RM30Cs to run full-range with the sub.  If the Cs cutoff at 55Hz anechoic, in-room response will be somewhere in the mid-40Hz range.  But there's that mode around 80Hz.  In matching the RM30Cs, the Sunfire Sub & this room, the sound dramatically improved by introducing an 80Hz high-pass crossover to the main speakers.  Also, the RM30M's lower cutoff would do nothing to improve the overall performance in this room vs. the RM30Cs.  Possibly if your room has a huge suckout in the range directly below 50Hz, the RM30Ms greater output in that specific range would cause an improvement, but absolutely, positively, not in this room.  And not if the sub was capable of properly filling in this range.  I know because I've had the Ms & am now using the Cs.  Plus see above: the Cs sounded far better crossed at 80Hz vs. full range.  Another view: the higher the main speakers are crossed, the wider the sub's range, the wider the sub's range, the wider the positive effect of its automated EQ, the wider the effect of the EQ, the more likely the deleterious effects of the room modes are neutralized.  Of course, above a certain frequency the sub's performance suffers.  The room can affect this frequency.  At that point the deleterious effects of the bass being xd too high starts to outweigh the benefits of the EQ.  

An added bonus of crossing the mains up higher is greater potential output with lower distortion.  Playing loud movie effects resulted in the standard 6.5s bottoming out playing full range.  With the 80Hz crossover the problem is gone.  I'd imagine even the ribbon midranges are better filtered & stressed less with the 80Hz high-pass crossover.                    

The sub is equalized for flat output in the vicinity of the main listening area throughout its entire operating range.  This room's 80Hz mode minimizes output requirements of the sub above about 70Hz.  The sub has absolutely phenomenal performance in this room setup as described.  The VMPS Larger Subwoofer was recently here with all the latest available upgrades (found a happy home at Zybar's place).  Believe it or not, the Sunfire's power is on par (in other words, shocking quantities of bass) & it goes almost as deep.  But beyond that, in this room, the overall performance of this sub blows away anything I've heard.  The overall effect reminds me of  the Inifinty IRS IIIs (12x 12" woofers, $65k in mid-1980s dollars) heard at the home of one of Brian's customers.  That room was incredible.  My way-awful 30Hz mode is plain gone, & the less obtrusive 80Hz mode is invisible.  The blending between the sub & main speakers is seamless & transparent, & I spent almost no time tweaking it!  The RM30C passive radiator tuning could be improved, but it matters so little because of the 80Hz high-pass crossover that I've not bothered.      

This system's maximum SPL with a 5x 400WRMS amp is beyond the threshold of pain.  The room's maximum playback envelope was greatly expanded by the EQ'd sub.  I was adjusting the volume control on a new preamp's remote.  The change in playback level slightly lags the control button when it is held down.  Before I became familiar with this lag, I made the mistake of holding the button down too long.  When the volume finally caught up, the ensuing sound was so loud & literally terrifying that the remote flew out of my hand.  I had to scramble to the floor on my knees to pick it up.  Yet there was absolutely no audible distortion.  We are all familiar with the sound of gross distortion.  This had no artifacts yet was louder than I've heard, possibly since being at the Sausalito Record Plant Studio with Sly Stone in the early '70s (19, not 1870s).  The control room was medium-sized with 8x 15" JBL woofers, 4x huge horns, 8x 300WRMS Crown amps & active crossovers.  After a friend made the same mistake, he corrected it, turned his head slowly toward mine, his face was white, he handed me the remote & said he did not want the responsibility.  The benefits of this output are evident from whisper levels to the loudest crescendos: an ease & effortless quality only available with huge dynamic reserves under every condition.  I listened for distress playing the loudest movie effects & have been amazed every time: no audible distortion.          

In this room, I would never for an instant consider going back to non-equalized bass again.  If the RMX were substituted in this room for the current system (without the Sunfire & its automated EQ), the bass mode problems would far outweigh any potential RMX benefit in the upper registers.  The worse your room modes the more likely this would apply to your own listening experience.  I thought the only way to fix my room's bass mode problems was to build a new room or install a messy, hard to setup outboard parametric EQ until I planted this Sunfire Sub in it.  On the other hand, Brian's subs are a superb alternative if you have space, don't have a bass mode, &/or you have a room mode & are willing to employ an outboard parametric EQ.  Brian said a few months ago he has a combination amp/eq/xo coming.  Budget constraints plus having a good amp laying around to use for the sub would also tilt in favor of Brian's.      

That's my story & I'm sticking to it.  I'm sure, God wiling, Brian will be selling something better than the RM30s one day.  It's going to have to be one heck of an improvement for me to consider upgrading from this rig, which exceeds virtually every expecation I've ever had for reproduced sound.  If Brian's next greatest speaker is less cosmetically acceptable, I doubt very much I'd consider it at all, regardless of how good it sounds.

Happy listening!

[Enrico]

A very interesting post. I've got a couple of EQ'd subs and have been pondering issues such as: speakers full range or cut off at 80 Hz? RM/X or RM30? (plus a few other contenders). Your comparison to the Sausalito control room system is provocative but if you're right it's a heck of a compliment to all the manufacturers of the stuff you're using.

[Sedona Sky Sound]

Wow. That was an interesting read. It is good to hear that you have found the "audio nirvana" that you were looking for    .

The one thing that puzzles me however is why did you not just treat the room to get rid of the room modes? Knowing that you are into DIY and woodworking/speaker building, a true HelmHoltz resonator tuned to 30Hz and a panel resonator tuned to 80Hz should be relatively straight-forward (but not necessarily easy) projects. Just curious.  

Julian

[James Romeyn]

The "not necessarily easy part" is the problem.  I've got a new job with new responsibilities & the DIY part of this hobby has lost most if not all its magic for me.  Plus my bike habit of 11 miles per day takes up a bit of my daily routine.  How much space would the appropriate resonators take up in the room?  Would they go in the corners only?  I have the equivalent of one 4' length of the largest ASC bass trap in one corner.  It helped smooth out the  modes before the EQ'd sub arrived.      

A funny thing while I was researching the sub is that I could not find one dealer (I called maybe twenty) who had the new EQ model in their possession.  You'd think they'd be pumping this thing like crazy.  Go figure.

Hey, does anyone know why Horsehead became so rabid against VMPS after all the great things he used to say when he owned RM40s?  His signature used to state that his was the home of the first TRT'd RM40s.

[Rob Babcock]

I don't think he's really "rabid" against VMPS- I think he just moved on to speakers he thinks sound better.  Didn't he end up with some Timepeices?

[zybar]

If you go back and read Horsehead's posts you will see that his issues with VMPS weren't about the quality of sound.

He did move on to SP Tech Continuums, but has since sold them and moved onto to other speakers.

As for room treatments...I highly suggest the use of MiniTraps.

Glad you are enjoying your system Jim.

George

[Rob Babcock]

I don't want to put words into his mouth, but didn't Horsehead sell his current Timepeices in anticipation of a newer (custom?) floorstander from SP Technologies?  That was my understanding, unless I'm thinking of someone else.

[zybar]

I don't want to put words into his mouth, but didn't Horsehead sell his current Timepeices in anticipation of a newer (custom?) floorstander from SP Technologies?  That was my understanding, unless I'm thinking of someone else.

He had Continuums, not Timepieces.  

He didn't go in that direction at the end of the day.

I will leave it him to post his system these days.

George

[Rob Babcock]

Hmmm...so many guys on the gear merry-go-round!    It's hard to keep track.  Thanks.

[Sedona Sky Sound]

The panel resonator for the 80Hz mode would take up very little space. Not knowing your room it would be hard to tell exactly what size you would need, but my random SWAG is that two units 2'x4' and perhaps 6" thick would do it. You could hang these directly on the wall at one of the node maximum locations or angle them in one of the corners.

The 30Hz HelmHoltz resonators are going to be a little bigger. I made mine from the largest 4' sections of concrete form tube I could find at Home Depot (think giant paper towel tube). So in my case they ended up being 4' tall and 13" in diameter (actually, 4'x14" square after I put them in a frame and covered it with cloth). Two of these pretty well totally eliminated my 28 Hz mode. A side benefit is that the round form also acts as a diffuser to some extent. I can effectively tune the room just by moving the resonator one or two inches (which was VERY important when optimizing the RM/Xs). When making the resonators, I think I spent probably 20 hours researching and making sure I was using the right formulas (SUPER, SUPER IMPORTANT that you use the right formulas and triple-check them since some of those listed on the Internet are incorrect). However, it only took me perhaps 3 hours to make the resonators once I knew what to do and had all of the materials handy.

While not true outside of the US, there are very few US homes in which a Bass Trap would be totally beneficial. While they may help tame a certain bass mode above 70Hz or so, they are so broadband that they will suck the life out of the bottom end of a room (and mid-frequencies as well in many cases). In most US houses the drywall already sucks up so much of the bass that the RT60 times for 125HZ and below are probably less than half a second. Their only benefit over a resonator is that they are easy to purchase and place in any room, where-as a resonator needs to be custom built for a certain frequency. However, a resonator is pretty much the only option for modes below 50Hz since a bass trap would be prohibitively big (i.e., several feet in diameter). At a couple of my customers, a zero cost improvement to the sound was made just by moving the listening position so that it corresponded to a null or pseudo-null.

While I may carry outboard equalizers and products with built-in EQs in the future, I have not done so yet. I have not tested the latest batch of products, but those that I tested a few years back (primarily mid and high-end professional equilizers) significantly impacted the sound in an overall negative way. Most smoothed out the bass/mid response but tended to turn the pristine highs I listen for to mush   .  As such, I just do not have much faith in analog EQs. However, the newer digital EQs (those that modify the digital signal prior to DA coversion) do look promissing. Now if they could just put them directly in the high-end SACD players or make a processor that sounds as good as a good analog pre-amp, I would be very happy. Untill then, I am firmly stuck in my belief that the physical room is the most important part of any audio system (and this coming from a dealer that sells spreakers and electronics but no room treatment, go figure   ).

Happy listening.

Julian
www.sedonaskysound.com

[James Romeyn]

The examples of Horsehead's rabid negativity about VMPS & Brian are evident in the threads several months ago between B & someone else whose name I flatly refuse to write ever again (another AC forum speaker manufacturer).  Horsehead made inflammatory criticisms.  When we talked earlier he was considering trading his pair of RM40 TRTs for RMX'.  The 180 degree turnabout was so shocking I had to re-read the text, avatar & screename to confirm it was the same guy.

I forgot to mention, there are a sum total of two active low-pass XOs in series on the SW.  The pre-pro is set to 80Hz (slope unknown) & the sub's internal XO is set to 65Hz@20dB/octave (slope continuously varies from third-order@30Hz to fourth-order@100Hz).

Considering how good the dual-pole XO described above works (& employed by Brian on the ribbons of RM30's & other models), I'm surprised dual-pole XO's aren't more common in speaker applications.

Julian, when you want to write a high-end manual (specificaly maybe a room treatment manual with other misc high-end stuff), talk to my wife about publishing it.

[Ric Schultz]

Jim,
What Pre-pro are you using and how is the high pass xover to the main speakers done.....external active crossover or passive one?  Thanks.

[James Romeyn]

It's the 2004 $3500 Sunfire Theater Grand IV designed by Bob Carver.  A digital source feeds the TGIV.  I presume all the filtering iniside is performed in the digital domain, for a sum total of one D-A conversion above the subwoofer range.  

Meanwhile, the sub is fed a variable analog output from the TGIV.  It appears safe to presume all the sub's processing/EQ & filtering is performed in the digital domain.  Meaning the sub adds more A-D & D-A conversion, for a sum total of two conversions in this system's subwoofer range.

With the calibration mic plugged into the sub, it takes just a few seconds for the sub to play it's swept test tone covering its entire range (the filter is set to the highest frequency or switched off, I can't remember), then it makes clicking sounds while it self-tunes depending on the feedback from the mic, then it plays the swept tone again (I presume to confirm the results are flat), then you unplug the mic, make some minor filter pole adjustments, & you listen, then think to yourself: this result can't possibly be that easy, no way!  The difference between the uncorrected & corrected swept tone was readily apparent.  It's nice that I could tune my room with the double doors closed for more privacy too.

When a sub with the exact same specs & technology is made by Martin Logan or Linn circa 2011, you can bet your ass it's gonna cost $9000-$15,000, have zebrawood veneer, & Stereopile will sing its praises, tell us it's a revolutionary breakthrough, & what a great deal it is.

[audiot_savant]

Are you using the high pass of the sub or an external high pass?

On a personal note, you mention a new job.  No longer fighting fires or just get a promotion?

Regards,
Randy
(my wife and I were at your place in the fall of '03)

[audiot_savant]

Oops--our visit was the fall of '02.  

Tymlexically yours,
Randy

[James Romeyn]

Still firefighter.

The high-pass is in the pre-pro, avoiding another stage of digital conversion, interconnects, etc.  The only thing I don't like about this pre-pro is that dimming the too-many lights can be performend only on the front panel.  It seems to have less distortion, noise, & better dynamics & overall sound vs. the McCormack MAP-1 used previously.            

Happy Reformation Day to all.  It's ironic that Martin Luther's posting of his 90-odd complaints against the Roman Church & halloween are celebrated about the same time every year.

Man this new Dell computer makes my ancient Toshiba laptop seem like an antique.