Review of VMPS, Son of Ampzilla and NuForce systen

mlawson66 · « **on:** 6 Sep 2005, 11:10 pm »

This review has been a long time coming as the system has been in such flux. I can only blame and thank John Casler for all of this as he has been an incredible source of information and quality gear.

The system as it stands today is as follows:

A pair of RM30s with Auricap.
An LRC with FST.
4 626-R with FST.
2 SVS PB12+.
Son of Ampzilla + 2 NuForce Reference 9s driving the subs.
1 NuForce Reference 9 driving the LRC.
1 Outlaw Audio 7x220 watt amp (soon to be replace with NuForce 8bs).

HT pre/pro Sherwood Newcastle P-965
Denon DVD 3910 DVD/SACD
Krell KAV 280P 2ch preamp
Jolida CD
Musical Fidelity X-series power supply, DAC and tube buffer
Sansui TU-717 (with a good local station)

This system sounds incredible but lets not get ahead of the story.

In the beginning there were 2 626R/FSTs and an LRC/FST and it was good. The Son of Ampzilla did an admirable job. Movies came to life. My old Athena mains did an adequate job as surrounds. They did look kind of funny standing on top of the SVS boxes though. Well, we all have to make our sacrifices for sound.

The next phase was initiated by my wife. I think she might have been influence by the instability of 4' speakers sitting on top of 3' subs but she said that the sound coming from these speakers was warm and fuzzy compared with the mains. I tended to agree. That and the Athena "dipole" speakers that were bringing up the rear must have got lost somewhere along the way. They just plain sucked.

Phase 2. Intro RM30/Auricap. Wow, I've actually got a good 2 channel system now. Maybe a bit light on the bass. OK, I've got 2 extra channels on the Outlaw, why not have them add some bass. Well, the SoA breathed a sigh of relief and made the top half of the RM30s open and and sing. Man, I had no idea there was so much information in the mids and highs of all my favorite albums. I had to listen to everything I owned again. It was almost like that was all new music again. So that is what trebles sound like when they aren't sibilant. Nice.

Phase 3. These Athena speakers have got to go! We added 2 more 626R/FSTs. The Sherwood has a "matrix" surround setting that makes none surround encoded material come to life. Now we actually turned the surround speakers up. Wow, I didn't know that internet radio could actually sound good enough to listen to. Wow, the broadband connection can make music now. We have a mac mini with 768 GB of music encoded in a lossless format that can finally really be used. The surround speakers have enough information to distract you from the fact that you aren't listening to vinyl or a DAC on steroids. Oh, yes, I have to admit I'm a geek and my old sci-fi collection is much more interesting now. Phasers are a 3 dimensional phenomenon now. Brothers in Arms is an all encompassing event now. I actually felt like I was in a fox hole the last time I watched Brothers In Arms. How the heck did they make it feel like the bombs and machine guns were happening above my ears?

Phase 4. NuForce Reference 9s on sub duty for the RM30s. You know, this Outlaw amps makes lots of bass, but it kinda sucks. It is boomy, lazy and late. It makes me think of Fat Albert taking a seat on my favorite tunes and crushing them. Hey hey hey, you never thought it was supposed to sound this way. Uh, yeah, I've always got the last word you know. Jeezus, how can we let this slide, the SoA is making sweet mids and trebs but the bottom end has been squished and all but laid to waste. Well, thanks to John, we now have some little black boxes with big black and blue secrets. If you don't look out, they will lay the whammy on you! I swear the last time I was rocking out I saw plaster falling from the ceiling. Who knew that this little box the size of my headphone amp would make the floor dance and try to do somersaults? I can only listen to the system at its full potential when the missus is away, that and they are having speed boat races down on the lake. All the police and the anti-terrorist units are watching the show instead of listening to the bombs going off in my living room. Suffice it to say that the NuForce amps make subs do what they were meant to do and maybe a bit more.

About the NuForce speaker on the center channel....
Well, it isn't completely fair because this channel is being fed by the Newcastle instead of the krell but this channel is warm and engaging. The emphasis is on the midbass and mids. It is a perfect match for movies and such. If there is any bass on that channel, it is faithfully reproduced. The trebles are there and not sibilant. They just show up when you expect them, not as an uninvited guest. These amps rock. Hey NuForce guys, good job.

The next phase is a Krell Showcase followed by 4 more NuForce amps. So long Outlaw Audio/Fat Albert amp!

KJ · « **Reply #1 on:** 6 Sep 2005, 11:37 pm »

Quote from: mlawson66

NuForce Reference 9s on sub duty for the RM30s.

Did you get the modified version since you are dedicating them for bass?

-KJ

mlawson66 · « **Reply #2 on:** 6 Sep 2005, 11:47 pm »

I didn't know about the modified version when I ordered. I asked Jason of NuForce about it and he offered to do the mod for $20. I think I will just order the next set with the mod and shift them around. The roll off is bearly noticible in 2 channel mode. In HT mode, since the crossover is at 40Hz, there is not rolloff at all. If the bass comes up much more, I'll have to cap the volume to protect the plumbing and sheet rock...

So, since I have the day off and the missus is at work, I've found the sweet spot to be 98dB as measured on the Radio Shack meter. This sounds as close to live as I've ever had any home gear sound.

mlawson66 · « **Reply #3 on:** 6 Sep 2005, 11:51 pm »

Yep, I can only qualify the bass response now as something like brass knuckes. I think the bass enhanced version would be more like a lead pipe.

mlawson66 · « **Reply #4 on:** 7 Sep 2005, 12:20 am »

The question prompted an empirical expirement. The SVS speakers in the HT system are set to peak at 16 Hz. The subs in the RM30s are fed by a pair of RM9s without the bass driver modification (big fat cap that passes more bass).

Over a passage with significant bass, the RM30s give a solid bass resoponse just short of jeapordizing my fillings. There is noticible fall off at 30Hz. The SVS subs just about elicit the brown note over the same passage. I'm sure that the bass modified Reference 9s will elicit a similar response. I think I've damaged my Radio Shack dB meter... It seems that 92dB is the absolute sweet spot of the current configuration. At 98dB I actually saw the Son of Ampzilla ever so briefly flash its cutoff leds. Yep, 92 dB seems to be the place where it sounds most like a live performance, and the toilet isn't about to fall through from upstairs. The pine tree out front seems to be loosing an inordinant amount of needles but I can only hope to attribute this to the changing of the seasons...

mlawson66 · « **Reply #5 on:** 7 Sep 2005, 12:44 am »

All jocularity aside, the addition of the Reference 9s, even in their non-bass enhanced state has resulted in a huge improvement of "presence" in the RM30s. What I mean is that much lower listening levels sound "loud". We used to turn the system up to over 90dB to get a "full" sound. Now, 78dB sounds like there is a live band off somewhere in the distance, complete with some vibrations in floor and couch. At 92 dB, it sounds like front and center. Yes, I do look forward to getting the bass enahnced Reference 9s installed but I am definitely not unhappy now. Earlier, I wasn't joking about getting some gypsum falling from the roof. We have some tract lighting that I haven't gotten around to removing yet (funky 70's house) and it actually did drop some fine powder on the HT cabinet. The additional bass response will probably move the sweet spot from 92 dB to the 88-90 dB range. I'm not sure what the neighbors will think. It may be just as loud to them but the dB meter will be in less jeapordy.

jermmd · « **Reply #6 on:** 7 Sep 2005, 01:15 am »

mlawson66, I like your system. Are you running the RM30's full with subwoofer augmentation? If not, what crossover are you using. I'm sorry if this has been mentioned above but it wasn't entirely clear to me.

mlawson66 · « **Reply #7 on:** 7 Sep 2005, 02:12 am »

Hi Joe,

Thanks, I'm getting pretty proud of the beast too. It isn't quite through. I'm sure with a little more help from BioForce John, the system will realize its full potential. Anyway, the RM30s have the enhanced super sub option. I am bi-amping them with NuForce Reference 9s driving the subs and Son of Ampzilla 2000 running the top half of the speaker. The > 4000 damping factor elicits articulation out of the subs that I never even thought to look for in that frequency range. Notes from stand up bass guitars now prance around the soundstage like peacocks with enough resolution to see the individual feathers. That used to just be something like a peat bog. You knew there was something there but you could only see the surface and had no idea how deep it went...

mlawson66 · « **Reply #8 on:** 7 Sep 2005, 02:30 am »

Hey Joe, nice system!

Here is mine. I don't have a photo yet but here is the link...

http://www.audiocircle.com/index.php?action=systems;system=558

warnerwh · « **Reply #9 on:** 7 Sep 2005, 04:14 am »

It's certainly great to see we have another happy family member. Your system obviously sounds outstanding. You could go to Nuts About HiFi in Silverdale and hear some systems that would do well to compare to yours for ALOT more money. If you have the room and want extremely musical and extremely powerful bass ask John about the VMPS Larger subs. They are a bargain and with a pair of those you'll never want more. Brian is a true expert at designing accurate bass.

ctviggen · « **Reply #10 on:** 7 Sep 2005, 11:42 am »

How is your system setup? You're biamping the RM30s, and using the subs? Are you running the RM30s full range or are they crossed over? Are your RM30s the kind with 12 inch woofers?

mlawson66 · « **Reply #11 on:** 7 Sep 2005, 01:44 pm »

Hi Bob,

The RM30s are the MW type with the Mega Woofer enhanced sub option. I am not using any external cross over network in the 2 ch system. Since the circuit was designed to have the sub run full range, it didn't make sense to add any other phase shift into the system. A digital crossover might be fun to play with but this set up seems to be working nicely.

As for subs in the HT system, I've got 2 SVS PB12+ subs (total of 4 12 inch subs and 1800 watts). The HT system is set to cross over at 40Hz. The SVS subs are tuned to peak at 16 Hz. For movies and any music played through the HT system, the RM30s and their subs only have to reproduce frequencies above 40 Hz. That system is solid from top to bottom. Loud passages in movies provide a good back massage.

In 2 channel mode, there is a slight roll off at 30 Hz. This will be cleared up shortly when I get the Reference 9s updated with the bigger bass cap.

A word on putty. I neglected to mention that I had removed most of the putty during a previous stage in an effort to make the RM30 subs easier for the Outlaw amp to drive. The only thing the reverberates in the system is the TV and entertainment center. Oh, something in the LRC vibrates a bit when it isn't powered but I will have to live with that until I can get into another house and separate the HT system/listening room from the 2 channel system.

mlawson66 · « **Reply #12 on:** 7 Sep 2005, 01:52 pm »

Removed duplicate message

mlawson66 · « **Reply #13 on:** 7 Sep 2005, 01:52 pm »

Removed duplicated message

mlawson66 · « **Reply #14 on:** 7 Sep 2005, 04:31 pm »

I think the cat helped me out on the keyboard a bit

Very sorry about that.

ctviggen · « **Reply #15 on:** 7 Sep 2005, 05:32 pm »

That cat went crazy! So, you are driving the bass portion of the RM30s with one amp and the mids/highs of the RM30s with another amp, is that correct? I originally did this with my RM40s -- I drove the bass of one speaker with one channel of my Bryston 9B and the highs/mids with one channel of my Jeff Rowland. I stopped doing this only because I think the JR really doesn't have much trouble with the RM40s.

mlawson66 · « **Reply #16 on:** 7 Sep 2005, 06:58 pm »

Bob,

Yeah, I think the cat rearranges my stock portfolio when I'm not looking.

Yep, the sub section is being driven by NuForce Reference 9s and the rest of the speaker is being driven by a Son of Ampzilla 2000.

The Son of Ampzilla did a fair job driving the RM30s full range if maybe a bit light on the bass. It has a lot to do with my listening environment. That room is all over stuffed leather couches and no side walls for the bass to bounce off of. The initial reason for the bi-amping was to compensate for higher gain on the Outlaw amp in the HT system. I hated to have 6dB of extra gain dialed into the mains. Anyway, once we had the SoA driving everything but the sub, wow, it totally uncorked the mids and trebs. The Outlaw amp made more bass but it was kinda gross. I was going to get a second Son of Ampzilla to drive the sub sections to eliminate any phase discrepancies but the exceedingly high damping on the NuForce amps sounded like a perfect match for sub duty. If I had known about the big cap mod, I would have ordered it that way.

woodsyi · « **Reply #17 on:** 7 Sep 2005, 07:34 pm »

Nice!

Have you tried running Nuforce full way to see how it does the mid/highs?
Are you using your SVS subs with 2 channel. If so, at 40Hz lowpass? John brought his subs in at 35 Hz and really complemented his RM30s which roll off around 30 Hz. I am not sure what you mean by peaking at 18Hz. I didn't know that 12" SVS woofers went below 18 Hz, let alone "peaking" at 18 Hz. I am sure they are good subs but they have metal cones which would have different signature than mega woofers Brian uses... John didn't try to sell off a pair of Largers that he has as demos?

I bet Nuforce 9s on the Largers would mate better with your RM30s than 2 SVS subs with plate amps. You mentioned no sidewall reinforcement -- are you set up against a long wall? Is your listening position up against the back wall? Again, very nice.

jermmd · « **Reply #18 on:** 7 Sep 2005, 08:48 pm »

Could you elaborate on what the "big cap mod" and "Mega Woofer enhanced sub option" are?

Thanks,

John Casler · « **Reply #19 on:** 7 Sep 2005, 09:27 pm »

Quote from: mlawson66

This review has been a long time coming as the system has been in such flux. I can only blame and thank John Casler for all of this as he has been an incredible source of information and quality gear. The system as it stands today is as follows:

A pair of RM30s with Auricap.
An LRC with FST.
4 626-R with FST.
2 SVS PB12+.
Son of Ampzilla + 2 NuForce Reference 9s driving the subs.
1 NuForce Reference 9 driving the LRC.
1 Outlaw Audio 7x220 watt amp (soon to be replace with NuForce 8bs).

HT p ...

I'll take the blame and the thanks.

I think the reason I like your system so much is because it is quite similar to mine in many ways.

I also have to thank your wonderful wife who has helped you decide on some of the equipment, as well as not only allowed, but "encouraged" you to get it.

The reason we didn't think about getting the "bass" tweak of the Ref9s , is because it wasn't known to be available when we ordered, but we can do it on the next order as you say.

It makes me happy to see you are enjoying all the changes we have made so far, and its not over yet.