From a design perspective, I've never heard a room that looked anything like a rives room. Really curious what they sound like. So far the only one I know on the board that has one is mike lavine.

Mike, do you use active eq products from Rives, or is above a reference to your acoustic design?

It's kind of like the Adriana Lima of room acoustics. Don't overthink this metaphor.

I'm referring to only the room, not the equipment.

Last CES I went to, I think three years ago, I heard systems in several rooms treated by Rives and they all sounded outstanding.

Mike, do you use active eq products from Rives, or is above a reference to your acoustic design?

tzucc, i assume that by active you mean some sort of DSP or analog EQ. the answer is no. the whole idea of a purpose-built room is to avoid the signal path corruption of any EQ. and EQ can't really create the energy that a properly designed room can deliver.

OTOH my VR9SE's had numerous driver attenuators and an adjustable subwoofer crossover. my current 'loaner' VR7SE's have only have adjustments on the front facing 'super-tweeter' and the rear facing ambience tweeter. optimizing any speaker/room relationship can be greatly assisted with some adjustablity.

as far as characterizing a 'Rives' room; in general if one allows Rives to have a free reign (i gave them a completely clean sheet of paper and did not hold them back) then you will have a room that resembles a concert hall. which is to say it will try and allow the music to be free and breathe, there will be minimal absorbtion and maximum diffusion. the micro-dynamics of music and energy of the soundstage will be beyond previous music reproduction references. it will serve acoustically recorded music with tonal accuracy and textural shading.

as my room is quite large and i wanted to be able to recreate the full impact of large orchestral music i had lots of bass treatment built in; which in turn made much larger demands on my gear. for a smaller scale music focus you could scale things back a bit.

a Rives room will expose limitations of speakers and amps (unless it is designed for the capabilities of a particular speaker)......which was where i was when Chris visited my room. my speakers from that time (over 18 months ago) could not properly energize the room and some of my other gear was also not quite up to the level of truth the room was projecting. the room has a much more balanced and involving sound now than back then. almost all my gear (except tt and a few of my cables) is different now and speaker and seating positions are dramatically different. measured performance is also much better......a 'suck-out' at 80hz and a 'bump' at 135hz which i had blamed on the room went away with different speakers.

Rives can design a room to any set of sonic priorities or budget.....or do it 'their way'....or any point in between.

to answer the thread topic directly; i would describe a Rives room as 'Alive' and 'natural' and that the full capabilities of the gear will be enjoyed. a Rives room will be enjoyable at moderate as well as high SPL levels and will not 'lose coherence' on music peaks. instruments will be 'accurate' but also refined and nuanced. voices will be real and vivid. the flow and pace of the music should carry you along.

Hi Mike,

I wonder what the changes would have been if he designed your beautiful looking room on your request not only for stereo listening (as it's primary task now is) but as well as for HQ multichannel listening from SACD/DVD-A (and future HD HVD & BR).
You mentioned that before in general in other posts, if I remember it correct, but I would like to know which specific items would be different from what you have now. Any idea about this subject matter?

Regards, Rene

thanks.

the biggest difference would be the width of the room. for 'ideal' hi-rez multi-channel there are a couple of issues. first, you want all the speakers equi-distant......and second you want the rear speakers at 110 degrees from the center room axis listening position. for multi-channel that would require the room to be quite wide.....compared to ideal 2-channel.

at this point my ears are 14' from the tweeters of my speakers. if i were to have rear multi-channel speakers 14' from my ears and at 110 degrees my 21' wide room (already at about the width limit for home HiFi speakers) would need to be more than 25 feet wide. my room size would then need to be 36' x 25' instead of 29' x 21'. 36' x 25' is just too big for the sort of intimate dynamics i enjoy in my 2-channel music. even if i move my chair forward from the 14' ear to tweeter point i still can't manage 110 degrees in my large room unless i really move my front speakers much closer together. i am not going to be moving my 375 pound VR9's or VR7's around whenever i do multi-channel. and my future 700 pound VR11's will be even more stationary.

i will do multi-channel but the rear speakers will likely be back at about 135 degrees; i will move my listening chair forward to reduce the tweeter to ear distance from my front speakers. i will still have the speakers eqiu-distant as i refuse to lose the full resolution of the hi-rez music with any sort of DSP delay.

a third, less critical issue, is the issue of speaker to speaker comb filtering which becomes more of an issue with discrete multi-channel. ideally you would have more absorbtion than diffusion in a purpose built muti-channel room as compared to my room. you could have movable absorbtion that could be added when you were playing multi-channel. my feelings are that when i do go multi-channel that my diffusion will be adaquate to handle the comb filtering. it will be a compromise but an acceptable one.

i have 10,000 2-channel Lp's and CD's which i love. even though i do appreciate the potential of multi-channel music the current reality is not sufficient to justify compromising my 2-channel music experience to optimize multi-channel. then you throw in the inconsistent nature of the multi-channel mixes......the various approaches are so far all over the board as to how the rear channels are used.....my choise seems obvious.

lastly, i have yet to hear any multi-channel compete with my best vinyl for that real music experience. 2 'real' channels go places that multple channels of 'gaps' just can't go. :D :D :D

tzucc, i assume that by active you mean some sort of DSP or analog EQ. the answer is no. the whole idea of a purpose-built room is to avoid the signal path corruption of any EQ. and EQ can't really create the energy that a properly designed room can deliver.

OTOH my VR9SE's had numerous driver attenuators and an adjustable subwoofer crossover. my current 'loaner' VR7SE's have only have adjustments on the front facing 'super-tweeter' and the rear facing ambience tweeter. optimizing any speaker/room relationship can be greatly assisted with some adjustablity.

as far as characterizing a 'Rives' room; in general if one allows Rives to have a free reign (i gave them a completely clean sheet of paper and did not hold them back) then you will have a room that resembles a concert hall. which is to say it will try and allow the music to be free and breathe, there will be minimal absorbtion and maximum diffusion. the micro-dynamics of music and energy of the soundstage will be beyond previous music reproduction references. it will serve acoustically recorded music with tonal accuracy and textural shading.

as my room is quite large and i wanted to be able to recreate the full impact of large orchestral music i had lots of bass treatment built in; which in turn made much larger demands on my gear. for a smaller scale music focus you could scale things back a bit.

a Rives room will expose limitations of speakers and amps (unless it is designed for the capabilities of a particular speaker)......which was where i was when Chris visited my room. my speakers from that time (over 18 months ago) could not properly energize the room and some of my other gear was also not quite up to the level of truth the room was projecting. the room has a much more balanced and involving sound now than back then. almost all my gear (except tt and a few of my cables) is different now and speaker and seating positions are dramatically different. measured performance is also much better......a 'suck-out' at 80hz and a 'bump' at 135hz which i had blamed on the room went away with different speakers.

Rives can design a room to any set of sonic priorities or budget.....or do it 'their way'....or any point in between.

to answer the thread topic directly; i would describe a Rives room as 'Alive' and 'natural' and that the full capabilities of the gear will be enjoyed. a Rives room will be enjoyable at moderate as well as high SPL levels and will not 'lose coherence' on music peaks. instruments will be 'accurate' but also refined and nuanced. voices will be real and vivid. the flow and pace of the music should carry you along.

Hi Mike, If you kept your room as Rives created, and added speakers and gear for 5.1 or 7.1 HT/Multichannel music, how would the room "perform"?

Hi Mike, If you kept your room as Rives created, and added speakers and gear for 5.1 or 7.1 HT/Multichannel music, how would the room "perform"?

i do plan on doing this in the near future. but it will only involve two additional rear speakers.....and no subwoofer. i will use the EMM Labs Switchman III with a 'phantom center' option to allow my front speakers to simulate the center channel when there is center channel information. if i were to add a center channel equal to my front speakers it would clearly compromise the 2-channel performance acoustically. the rear speakers should have almost no effect in my large room when i am listening to 2-channel other than the speaker cones themselves have a bit of resonance (which i would experiment with some sort of covers for) and having two large, massive, speakers in the rear......which will be like two additional persons standing back there. the biggest effect will be logistical...getting to the software on my shelves will be a bit more bother with two large speaker cabinets sitting back there.

my opinion is that the overall effect of those two speakers will be about the same as two more listeners in my room; which is to say not specifically audible. at least the speakers will behave themselves.

i did install 2" conduit in the floor for multi-channel interconnects and dedicated outlets for amps back in the rear corners.

even though i did install two power outlets in the ceiling for a future projector and motorized screen i will NEVER use them; they are for some future miss-guided HT nut that might buy my home.

i have a nice mid-level HT in my house that fulfills my 'foley stage' needs.

and to answer your question directly; i think my room would make a great HT room as far as 5.1 or 7.1. i also have 2" conduit for front subwoofers and center channel. the room has dedicated HVAC which is dead quiet and even hanging rear speakers on the walls the sound would be glorious with the way the room is constructed. the bass trapping is more thouroghlly designed than any HT i have seen. from an acoustical perspective it would be an ideal HT. with the light maple cabinetry the light management may be less than ideal unless you dealt with that. the floor is 6 inches of concrete and the size is very good. you are in a completely separate building with a nice foyer......kinda perfect HT setup.

Thanks Mike, great post.

What I specifically like about Mike's room is the size. A large room is just so much better in my opinion, because the size allows to greater reverberation without being unpleasant. Many people (and most rooms I've been in) have rooms which are more "normal-sized" rooms, living rooms etc type spaces that even when well designed and deadened sufficiently, are too dead. It's very difficult to get a small room to sound as good not just because bass modes are much more difficult to deal with, but because a small room demands a shorter RT60 time to sound "right," and this works nicely but you have a much smaller soundstage and less space for the music. This isn't just because the speakers are closer together and to you in absolute terms, but because the reverberation last longer and reflections are also more significantly delayed in a larger space. In a small room, almost all the reflections are very close to the direct sound, and that's bad, so you have to spend all your time wiping those out, and it's very difficult to maintain a diffuse soundfield while doing that. In the end, it can sound very very good, and extremely precise in imaging, but it doesn't have the size and depth and ambiance of a larger space.

A large room on it's own isn't always an advantage, because there are a lot of wealthy people with very large living rooms and big open lofty type locations with expensive stereos, and it just sounds hideous because they just stuck a stereo in a big bright reverberant space. And this sounds like a mess. I'd pick a small room that's very controlled over a big giant reverberant room any day.

But what makes Mike's space so unique is that it's so controlled and purpose built (VERY rare for large listening spaces as I mentioned) while being so large. It sounds like a "normal" room much smaller than it actually is when you're just in it, but it lends to the creation of music that's much larger than you could ever really get in a small space. It sound stupid to describe the music as being "more spacious" because of this, but that's what I would say anyway.

I think Mike's room would probably be great with multichannel. In my opinion, as rooms get smaller, the difference in RT60 time desired between 2-channel and multi-channel increases, and as rooms get larger that difference desired gets smaller. I think the best example of this is maybe the Seattle Cinerama, which is a very diffuse design (nested QRD diffusors all along the walls and wavy cieling diffusion along with larger wavy-wall diffusion design) which would never work in a very small HT space which should be much more dead. But in a larger space like Mike's, I think the need to be as dead for multichannel is less important, of course taken to an extreme with the large size of the Cinerama.

Definitely by far the favorite part of my visit to Mike's some time ago was the room. Although I haven't heard his new Von Schweikerts... ;)

I don't know what kind of bass performance the room has, the speakers he had at the time didn't have much bass. But looking at the design of the room, there's tons of very thick soffit trapping all over the place, and because it's so large, I would expect bass performance to be extremely good and relatively uniform as you move around. Again, another huge advantage to such a large lofty room.

btw, regarding clocking, I am thinking of getting one of the Lake eq units, which also feature an AES-EBU digital input and clock all of the following units from a precision clock generator, of which the brand escape me at the moment, but it has five clock outputs at like <5ppm jitter:
1) dcs dac
2) dcs upsampler
3) dcs transport
4) lake eq

That would be nice, since then you can avoid completely the A/D step that I think kills the sound in most digital eq solutions, while not losing the advantage of transport and DAC in sync by one master clock. It would be interesting to check this out.

p.s. the clock generator is an Apogee Big Ben... actually at the moment I can't find the clock jitter spec, but I recall reading somewhere it was like <5ppm. The DCS DAC presumably generates a clock at like <1ppm, according to a review I read by Atkinson of SP. Pretty good figures.

Hi Rene,

Thanks for the info. I just enjoyed about 2 hours of a 24 bit remaster of Phantom of the Opera. I have never, ever, heard a redbook CD sound that good. I highly recommend it... apparently ALW himself produced and approved of the mix. I upsampled this redbook to 24/176.

Anyway, thanks for the info on DVD... I will check out their website, I have not heard of this before. I was just reading that on an SACD of La Boheme that dCS A/D's were used to master from the 1961 tapes. Looks like dCS is the choice for highest quality studio work anyway.

I do wish they had three channel DAC out though... althought that would kill me since I don't have a matching X1 in the middle.

I know of the Verona, but don't think it has enough outputs, but I will check. Apogee has five. I need four. I don't know of Esoteric's GO, but I will check that out too... thx for the heads up.

Lake Contour EQ: http://www.dolby.com/professional/live_sound/Products/index.html
<Lake was acquired by Dolby sometime ago>.

Bruce Thigpen first introduced me to Lake, as they were the only eq he could find that did what he needed below 20Hz. The reviews and specs suggest to me that this is possibly the only EQ I would consider putting in between dCS and my speakers.

p.s. I am trying to get an eval unit of the Lake from our San Francisco pro audio dealer, but he says their eval unit is out on eval with some movie studio recording engineer. I get it when he's done.

I do wish they had three channel DAC out though... althought that would kill me since I don't have a matching X1 in the middle.

This is the absolute BEST indication to use the EMM Labs Switchman lll with the Phantom Center.

Rene, thanks for the intro to the Teac Esoteric line... never heard of it before. I didn't know more expensive gear than dCS existed... wow, that Teac stuff is pricey stuff. The clock gen sounds very impressive in specs, better than the Verona!

Rene, thanks for the intro to the Teac Esoteric line... never heard of it before. I didn't know more expensive gear than dCS existed... wow, that Teac stuff is pricey stuff. The clock gen sounds very impressive in specs, better than the Verona!

FWIW, Mike Lavigne had the entire Esoteric setup at his house in an a/b with the EMMLabs and the Esoteric at $68K didn't come close to the EMMLabs

IMO the EMM Labs gear is good but not the best!

Hopefully Mike Lavigne will chime in regarding the a/b test on Esoteric vs the Meitner


I owned dCS Verdi-Purcell-ElgarPlus-Verona. For stereo IMO the best available gear on earth.


I am curious therefore as to why you sold the best available gear "on earth". Defies all logic if such is the case

or post the link to his audioasylum thread

But I haven't heard better, even not by well appreciated EMM Labs.

Rene--I know that you too own X-2's

FWIW, when I heard the X-2 demo in Dave Wilson's living room, he used Meitner gear. I also know that in the past year he sold dcs gear on audiogon.

or post the link to his audioasylum thread


http://db.audioasylum.com/cgi/m.mpl?forum=hirez&n=200114&highlight=mikel+esoteric&r=&session=

thanks doc

I too have heard the Esoteric system. Very beautiful to behold and good sonically. However for me it was good from far but far from good.

that doesn't make his all mighty whatever. For examples he loves his speakers but I my Alexandrias. Better or worst?

Precisely my point as I have said countless times here on the board. This is a hobby,nothing more and nothing less. One man's passion is just another man's poison. To use such hyperbole as "the best stereo in the world" leaves me aghast. It is just your opinion. I have mine and everyone else has their own. A system is more than just the sum of its parts. It is an overall synergy. It is the room, the components, the sitting position etc, etc. Music from different components is in the words of fellow BAAS member Ron Party merely different "flavors". What you like, I might not and vice versa. Something wonderful in my system might fall short in your system. My mantra has always been "let your ears and your wallet decide". For you Rene, you have found perfection in the VTL Sigfrid whereas I have found what rocks my sonic boat in the very simple 18 wpc Lamm ML 2.1 SET and yet we have the same speakers. Long and the short of it is to say something smokes something else or this is the world's best stereo when all is said and done is tantamount to just your opinion.

i. if i were to add a center channel equal to my front speakers it would clearly compromise the 2-channel performance acoustically.
.
It may not compromise the two channel as much as you may think. There will be a compromise but it will mainly compromise the performance of the center if preference is given to two channel listening. I run a full range 50"by17" by 13", 140 pound center which is identical to my mains. I am able to push the center back about 20 inches and hear very little if any effect on stereo reproduction. BUT, the effect of having the center so close to the front wall compromises its performance. Being so close to a room boundary increase the bass response. The solution that I employ is to cross the center over at 80hz which removes the bass hump boundary effect I am getting. This though reduces some of the advantage of having a full range center in the first place. Still, having an identical center speaker blends almost seamlessly with multi-channel SACD. I have one particular recording where the female vocal is placed dead center. The illusion of the singer in the middle is excellent. With so much two channel material at your disposal and so little well recorded multi-channel tracks in existance, this is not worth a compromise with your two channel. My room has both absorption and quite a bit of RPG skylines and QRD734 style diffusers. My speakers does not respond well to having any form of treatments on the front wall between the front left and right. This lead me to believe that a large center would have the same result but it did not.

Guys,
I've noticed some of the posts mentioning 110 deg position for rear speakers in multi-channel configuration. This is so called ITU setup that seems to be not favoured any more for both recording monitoring and listening configuration. ITU will always cause a hole in the rear phantom image and causes problems with front-to-back image coherence. According to Michael Bishop who is a recording engineer for Telarc, no surround mixer is using ITU setup for monitoring any more. They switched to N.A.R.A.S recommendation which is at 135 deg position. You may read more at: http://db.audioasylum.com/cgi/m.mpl?forum=hirez&n=218644&highlight=Surround+Playback+Recommendations&r=&session=

Richard

LCR equidistant from the sweetspot is always preferred. Lining them up is a compromise used only when you have many listeners (such as in a cinema). If they're not equidistant, then you need time alignment and phase alignment (the latter usually not available).

... just your opinion.

you are absolutely right and everyones post no matter what they say is their own opinion (of the facts). Especially when it comes to best sound, best speaker, etc... That's why I never am offended if someone complains about Wilson sound, or Krell amps, or whatever. I believe them. They hear what they hear, and I hear what I hear. I only have to set the room up so that the brain I live with is happy. I can't optimize for the occasional visitors brain, even if I wanted to.

I happened to have the same opinion on dcs vs emmlabs, but that doesn't mean that you truly don't feel the reverse. Though I think we should use selected external opinions to filter information. For example, I did rely on your opinion specifically in making several eqpt decisions, not the least of which was upgrade from the WP to the X1-III's. For which I am grateful I listened.

Hi Bulldogger,

If you have 3 identical speakers in front L/C/R at equal distance to the hotspot, than automaticly the C will stand back compared to an imaginary line between the tweeters of L/R. I think that's the way to do it instead of L/C/R on the same line. Is that what you did?
--Rene
Yes. I found that I had to push the center back about 15 inches to eliminate its effect on the soundstage but continued to a position about 20 inche back as this was the limit of what I could manage. I will explain. First I optimized the position of the L/R with a sound meter to determine the best position to minimize boundary effects from my seating position, like the 50hz bump that exist in my room. Then I moved the center back to eliminate, at least to my ears, the effect on my two channel sound stage. I wish I could move it back further though I can hear no reason to do so but then boundary effect become too severe to manage by just crossing over the center . If I put the center dead up against the wall to move it as far away as possible from the imaginary line between the front L/R then effects are just too pronounced to control with the bass trapping that I am utilizing. I constructed two rather large, 6 feet tall by 18 inches in diameter bass traps which are mostly solid 6 pound density fiberglass, few air gaps. I have a closet at the rear of the room with Owen-Corning 705 panels inside. I also built a large seating platform, stuffed with fiberglass to act as a bass trap. Still, placing the full range center against the wall does not permit me to eliminate the boundary effect. Stereo imaging though is just fine. I was skeptical that this would work. I tried placing a 2' by 4' and two inch thick 6 pound density fiberglass panel between the front L/C. The results were disastrous, even with it being located further away on the front wall. My expectations were that the large center would also be unmanageable in this regard. That prove not to be true but just introduced another set of variables.

I always thought that a 5.1 multichannel 0-30-110 degrees set up was based on agreements for standards used for THX / movies and likewise for SACD and DVD-A. So for all MC the same speaker placement. The 0-30-135 degrees have a major impact on room layout.

No, the placement to match side arrays in a theater as recommended by Dolby (THX has gone off the deep end) is not the same as what one should do for multichannel music. Dolby recommends 90-110 degrees for the surround placement, and then 135-150 degrees for surround backs.

Ideally for a dual-use system you'd have duplicate arrays of surround speakers.

Chris,

HT & MC-audio in one set up - only 5 speakers available... what would be best in your opinion as fixed speaker positions?

A compromise between 0-30-(90..110) and 0-30-(135..150) degrees
= 0-30-(110..130) = 0-30-120 degrees ?!

Or is that not a compromise and it would be wrong for both?

I have to add that for stereo Wilson Audio advise a triangle with ratios of 1 for distance between front L/R and 1.1..1.2 for distance from L/R to hotspot. This result in not 30 degrees but some 26 degrees. For me I would easily make that compromise in movie sound for the benefit of stereo listening.

Likewise MC-audio would prevale above HT-surround, therefore I would obt for something like 0-30-135 degrees? Am I making the right decisions this way?

--Rene

It really depends on the use of the system. If you're watching mainly all movies, then I'd bias it towards standard HT placement as per dolby. If you're listening to a significant amount of multichannel music I would bias it towards that.

I would say that that I think most listeners if they are at all serious about multichannel music, even if they watch more movies than they listen to multichannel music, would find that placement for multichannel music is more important to get right than HT placement. The aggressiveness of many multichannel music mixes can rely much more heavily on surround channels for both output and imaging than HT surrounds which are usually much more purely ambient and strong precise imaging is secondary. Which is to say, in a multi-use system, choosing a multi-channel placement with the surrounds farther back may be very minimally degrading to HT performance, while choosing HT placement may be much more significantly degrading to multichannel performance. As such I would probably bias towards best multichannel performance. As always, you would want to experiment with placement in your room and see what works best for you.

Also another thing to bring up is that vertical placement differs between m-ch music and HT, for music you want all the speakers are ear height in the same vertical plane, while for HT you want the surround a foot or two above ear level, or more if they are a significant distance away (in a large room). Here if you are at all serious about multichannel music I would probably go for ear height for surrounds.

To answer your question, you'll get better performance working on the reflections and positioning of your speakers in your room (or changing your room) than you ever will by concentrating on the ratio of distance from the speakers to themselves, or to you. Room placement is VASTLY more important than distance of speakers to each other or to you.

That being said, angles and distances still do matter, but so much less than room placement. Becuase of this, the suggested angles don't seem to be of much use in practice, because if you get a better "sound" or "focus" by breaking their angular rules, you will and should break them.

To get best room setup, I suggest
1. hire professional (montlick, erksine, rives...)
2. Treat room
3. Put speakers on rollers..Move speakers all over the place with human vocals until you hear that magic stereo focus in the center. Without that focus, stereo isn't worth having.
4. Good luck on the rears, if you have the space, do step 3.

Real world listening is better than textbook theory. Experimentation beats knowledge in arenas such as this where the variables which you are able to modify are quite limited. (how many places could you really put your front or rear speakers?)
plasma doesn't mix with maxxII center :(
Do not waste your time putting great speakers in the back. The material that gets played back there is so anemic, it is HORRIBLE. The only time you will ever have something in the rear worth listening to, is if you have a well mixed sacd or dvd-a. Guess how many well mixed sacd and dvd-a's there are that are fun to listen to......5?

If you don't care about time in maximum enjoyment, and if you only care about having the best musical experience possible on a few recordings, then do it... Get identical front and rear setups, that also are symetrically responsive left to right front to rear... The MC music experience DOMINATES the stereo experience. Unfortunately there's not much material worth listening to, and movies put only garbage in the back.

So 0-25.75-142.5 degrees might be my choice as average of W/A stereo ratios (1:1.15=25.75 degrees) and average for MC-side/rear (135..150=142.5 degrees).Instead of trying to place speakers based on prescribed angles down to the quarter degree, I would locate the surround speakers by ear. This is all the more important if you're going to limit yourself to only 2 surrounds because you essentially have to provide coverage at your sides and behind you using a single pair of speakers (not easy). As such, they have to strike a compromise between side and rear placement in the surround field.

I would start with the surrounds along my sides, slightly rearward of the listening area, and slowly start moving them back. Play a mono signal through both speakers and try to listen for a phantom rear image behind you. As soon as you start to hear it, stop. If you move them back more, you'll further sacrifice imaging to your sides. If you bring them more forward, you'll sacrifice rear imaging, even end up with a hole in the soundfield behind you.

This location should give you a decent balance between rear and side imaging. When a car exits screen left, the sound should disappear to your left. When a plane flies overhead, the sound should disappear behind you. Everyone's hearing is different, which is why you can't go wrong using your ears to fine tune speaker placement.

Good Luck,
Sanjay

Rene: yes two surrounds in 5.1. Sanjay's point is that a 5.1 array is not enough to maintain strong imaging around the entire circle. With surrounds placed beside you, you maintain good imaging between front and surrounds, but poor imaging to the rear. With surrounds placed farther back, you recover imaging to the rear at the cost or poorer imaging between the front and the rear.

This is why 7.1 arrays are usually preferred where possible.

I wish source and playback material was good enough that we simply could use two speakers at 45 degrees in L/R front and likewise two at 45 degrees in L/R rear. That's ONLY FOUR -super- speakers !

--Rene

I do this, but I also use a center speaker. See the Toshiba HD DVD thread here at this subforum for my system info. Many folks say they haven't heard better surround. But you need proper acoustic treatments so that your front stereo pair give excellent phantom center imaging - even though I use a center channel.
My audiophile friends all initially were concerned that the 45 degree angles up front were too far apart - but they have come to agree that thanks to adjustments with my Michael Green Pressure Zone Controllers, that my front speaker imaging and phantom center imaging is to die for. HA!

Your description of how to use sound and ears for proper position is appreciated. I expect and hope the professional helping me will work likewise.You're welcome. And even with a professional helping out, I would still recommend trusting your ears for some things. For example: if he tells you that you should be hearing something with your speakers at a certain location, but you don't hear it, then move the speakers around until you do. Sorry if this seems like common sense, but it never hurts to repeat it. The fine tuning should be based on your personal hearing, not what the average listener would hear. Logic7, Circle Surround and other processor software is the (as far as I know) to translate a 5.1 source signal to a 7.1 side+rear speaker signal.They do, but it's up to you if you want to use surround processing with music. If you use Dolby Pro Logic IIx on 5.1-channel sources, the critical front soundstage will be left completely untouched. The only processing that occurs is in the surround field, where 2 surround channels are steered over 4 surround speakers. Sounds that would have normally phantom imaged behind you are extracted and sent to speakers physically placed behind you. The remainder of the sounds are kept in the side speakers. Directionality remains somewhat the same, but envelopment and imaging stability are improved. Now you speak about my situation as ONLY 1 side/rear speaker per side. Isn't is standard to have 5.1 in MC audio, 3 speakers in front and 2 behind?Yes, that is standard. The reason I used words like "only" and "limited" was in order to emphasize the difficulty in imaging the entire surround field with a single pair of speakers, and the extra care that must be taken with placement. It's easy to get stable rear-vs-side imaging with 2 pairs of surrounds: just place one pair at your sides and another pair behind you. You don't have that luxury with a 5.1-speaker set-up, where you're relying much more on phantom imaging to localize sounds. Again, sorry if it seems like I'm repeating common sense, but I can't emphasize enough the extra care that should be taken when placing a single pair of surrounds.

BTW, the same applies to the front soundstage. If I were using only 2 speakers, then I would have to place them extra carefully in order to balance having a wide soundstage and a stable centre image. With 3 speakers across the front, I could spread them out in a rough manner and never get hole in the soundstage or unstable central image. in that case I have to start saving coins again... Actually, I wasn't trying to get you to buy more speakers. Just wanted to emphasize taking extra care in placement, especially for the surrounds. I wish source and playback material was good enough that we simply could use two speakers at 45 degrees in L/R front and likewise two at 45 degrees in L/R rear.The problem is not the source material or the speakers. It's the limitations of our ear/brain mechanism. Just one example. We localize sounds based on comparing the input to both ears. That's how phantom imaging works. With sounds that are meant to be reproduced directly at our sides, there is a problem. For all intents and purposes, we're only using one ear to localize the sound; the other ear is in acoustical shadow and not helping. That is why it's important to have a pair of surrounds directly to your sides. But doing that leaves you with a sonic hole in the soundfield behind you.

Again, this isn't a problem with the speakers or the source material, just the way our human hearing works. If we did have consistent hearing all the way around, or if we could point our ears the way we point our eyes (without moving our heads), then we could sit in the middle of a giant X and have speakers at +/- 45 degree locations. Whenever I see cats or dogs or horses rotate a single ear in response to something they heard, I get a little envious.

Best,
Sanjay

Again, this isn't a problem with the speakers or the source material, just the way our human hearing works. If we did have consistent hearing all the way around, or if we could point our ears the way we point our eyes (without moving our heads), then we could sit in the middle of a giant X and have speakers at +/- 45 degree locations. Whenever I see cats or dogs or horses rotate a single ear in response to something they heard, I get a little envious.

Best,
Sanjay

Ask Mike Parker, Bulldogger, Mark Burnstein, Scott (Hometheaterguy), Bob Williams (Owner of Audionut.com), Don Hoglund (Granite Audio owner) and others who have been at my place - my Aerial 10Ts at 45 degrees, even not using the center channel CC5, leave no whole and outstanding phantom center imaging (provided of course with no center that one sits in the sweet spot center). It can be done - again, my Michael Green Pressure Zone Controllers allow me to place the front speakers farther apart, yet maintain a wonderful phantom center image, even though the front speakers are at 45 degrees.

What is the distance from hotspot to your front speakers L/R and C ?

What is the distance from the wall behind the speakers L/R and C ?

What is your room L/W/H ?
Distance from behind the speakers is 45 inches for the front L/R and 27 inches for the Center. My room is 25 feet by 17 feet by 9 feet. You are not going to try to use a room mode calculator are you? Those give generalizations but only that. My walls are not typical construction and I have a couple of hundred pound of fiberglass absorption in the room. Room mode calculator will not match up with actual measurements. I used actual measurments to place speakers. My front three speakers are all the exact same 125 inches from my seat. I am using a three full range fronts, and two sides go down to 60 Hz, two rears also go down to 60 Hhz and two subs. Fronts L/R are run full range with center,sides and surrounds crossed over at 80 HZ. I think 7.1 is the way to go. In my set-up it provides significantly more immersive surround sound.

Hi Steve,

First time I see somebody -you- did this +/-45 degrees speaker placement... amazing, my spontaneous wish is your real live set up!

But I have to admit that together with your audiophile friends I share the concerns of the proper image and still can not believe it to be the right thing. That especially for stereo because the front L/R stand some 75% further from each other than what is regular AND recommended by the developers of the speakers themselve. As you could have seen in my post Wilson Audio describes a placement ratio of 1 for distance between L and R, plus 1.1-1.2 for hotspot to both front L/R. The average result in 25.75 degrees or 51.5 degrees of the triangle. You at 90 degrees... that MUST translate to a different sound image or a center gab or what ever. Or are you playing a stereo disk always over three L/C/R speakers with software to spead it?

I looked at MG's site and his treatments like the corner, wall, ceiling, floor standing PZCs. Can you describe how you positioned them so you were able to manage the proper image as you said?

Regards, rene

Rene,

If you're ever in the Phoenix, AZ area you can demo my room as long as you want!!!!

I'm not gonna get into great detail cause I'm a "retired tweaker" with other things to do. HA! But basically I have the three PZCs placed along side walls equidistant, 1/4 from front wall, then 2/4, then 3/4. PZC angled 45 degrees in each room corner. Smaller PZCs above each speaker on ceiling. There's a tuning bolt in front of each PZC and you adjust it to get the sound how you like it.

If you do a websearch for Pressure Zone Controller, Michael Green, or James (Jim)
Bookhard (a fierce PZC advocate and great guy), you will find lots more detailed info.

All of my audiophile friends initially shared your concern re speaker placement, but after listening in my room a number of times each of them became convinced that whatever I did, they wouldn't change it - that stereo alone has outstanding imaging including phantom imaging.

My front row center sweetest spot chair is centered among the speakers.
However, when I listen to music, I do tend to pull the chair back just maybe a foot or two for even better sound - not necessary for home theater.

. Furthermore I'm afraid of all that absorption, even for MC-audio or surround HT. I prefer diffusion if you have do treatment and focussed absorption in vertical corners and on specific problem freqs.

Do I understand it correct that with your L/C/R placement as it is you have no interference at all of the dead (big) center in case of listening stereo only?

Regards, Rene I have A LOT of diffusion as well as absorption. See the problem with absorption is that is kills the highs. I tried for a very long time to get a good sounding room using absorption only. I personally do not believe that is possible. What I discovered was that the RPG Skylines in conjunction with absorption work extremely well. The RPG Skylines really bring the highs back after you add the absorption. In fact, another forum member and I found that the RPG Skyline can actually make the room sound too bright. Rutgar, the mentioned forum member had Rives design his room. I viewed his design and then contacted RPG to ask about what Rives had recommended for the use of their products. RPG backed up the Rives design and then gave further tips on other products that would work well in a similar design. I then found wooden RPG style QRD 734 diffusers on ebay. Terry Montlick, forgive me Terry if I misspelled your name, an acoustics expert that post here on the forum was kind enough to look at the diffusers and advise me if they were "the real thing." He was also generous enough to offer me tips like covering them with fabric to enable the QRD to also absorb some frequencies. As for the large center with stereo, no I do not hear an effect. My expectations were that the large center would kill my stereo image. It did not. I come from a two channel background. Many guys here advanced from AV receivers to separate AV components. My background is Audio Research and Audible Illusions tube pre-amps and vinyl:). Perhaps my history will let you see that I do take the reproduction of two channel audio seriously and do not say lightly that my two channel does not suffer from my full range center. In theory, it should. Perhaps you can measure it's presence. But in practice, my two channel is excellent. Here's Rutgar's room, that I copied http://home.mindspring.com/~rutgar/id8.html The only thing that I need to do is buy MORE RPG Skylines. I love what they do for stereo.

s and if you only care about having the best musical experience possible on a few recordings, then do it... Get identical front and rear setups, that also are symetrically responsive left to right front to rear... The MC music experience DOMINATES the stereo experience. Unfortunately there's not much material worth listening to, and movies put only garbage in the back.
I fully agree with these statements. Steve Bruzonsky's set-up has a superb stereo image. You may think that you can get small book shelf speakers to fully blend in a 5.1 set-up when the mains are full range. Truth is that it never really works. You are always reminded that the fronts if large floor standers, do not match the rears. The first set-up that I heard that used full range rear speakers was Steve's. This is a HUGE advantage for music surround reproduction. With music, at least for me, the goal is for the surrounds to add ambience to the room and not draw attention to themselves. That's impossible with "lesser" speakers on the rear channel in a 5.1 set up. If you use 5 full range speakers and position the speakers properly, there is no hole in the sound stage. With movies it is somewhat different. With movie mixes the surrounds are sometimes mixed to call attention to the action going on in the rear channel. In this case I find that I prefer 7.1. It seems that two sets of rear speakers create so much energy and such a broad sound field that your attention is not called to the speakers. My conclusion is that if you are not going to use surrounds of equal quality to the front channels, 7.1 is a must. Here I also tried unsuccessfully to get smaller speakers to blend with my large front speakers. When I switched to a 7.1 set-up, the difficulty blending the rears largely disappeared. My set-up did have a hole because my side speakers, on wall speakers, are limited in their placement. The addition of the rear speakers on stands that allow me to angle them, gave me the sound I was searching for. Two Matin Logan Descent subs completed my room. Another topic is the use of a single sub. I never could get even bass with just a single sub. Two were the ideal solution for me. Well maybe four when I decide that it is time to upgrade:D.

s
I fully agree with these statements. Steve Bruzonsky's set-up has a superb stereo image. You may think that you can get small book shelf speakers to fully blend in a 5.1 set-up when the mains are full range. Truth is that it never really works. You are always reminded that the fronts if large floor standers, do not match the rears. The first set-up that I heard that used full range rear speakers was Steve's. This is a HUGE advantage for music surround reproduction. With music, at least for me, the goal is for the surrounds to add ambience to the room and not draw attention to themselves. That's impossible with "lesser" speakers on the rear channel in a 5.1 set up. If you use 5 full range speakers and position the speakers properly, there is no hole in the sound stage. With movies it is somewhat different. With movie mixes the surrounds are sometimes mixed to call attention to the action going on in the rear channel. In this case I find that I prefer 7.1. It seems that two sets of rear speakers create so much energy and such a broad sound field that your attention is not called to the speakers. My conclusion is that if you are not going to use surrounds of equal quality to the front channels, 7.1 is a must. Here I also tried unsuccessfully to get smaller speakers to blend with my large front speakers. When I switched to a 7.1 set-up, the difficulty blending the rears largely disappeared. My set-up did have a hole because my side speakers, on wall speakers, are limited in their placement. The addition of the rear speakers on stands that allow me to angle them, gave me the sound I was searching for. Two Matin Logan Descent subs completed my room. Another topic is the use of a single sub. I never could get even bass with just a single sub. Two were the ideal solution for me. Well maybe four when I decide that it is time to upgrade:D.

Thanks for the compliment re my stereo imaging and sound and the same for my multi-channel. I should point out that its better since you were here. That's because when you were here, I used five main and three sub outputs from the CB3, with five main and one sub via the Six Shooter and two subs via the CB3 direct. When I checked speaker levels it all sounded fine. However, you pointed out that the CB3 direct connected channels don't level correct when using only one Six Shooter. After getting HD DVD, I rearranged system with only one sub output from CB3 via Six Shooter and chaining the other two Aerial subs, so a 5.1 system with 3 subs chained. When you came, I didn't use phantom rear center, had it off, because it interfered with my front center voicing. Now I know why = the level problem. Now I use phantom rear center for everything that I can.

So now on reg Dolby Digital and DTS, even stereo PCM using Circle Surround,
my sonics and surround imaging are even better than when you were here.

I'm glad Bulldogger feels that equal excellent imaging full range loudspeakers all around, 5.1 can sound awful good; and I agree that 7.1 is a must for on wall or lesser surround speakers when full range can't be placed within room like front speakers. I wouldn't mind having 7.1 or 8.1, but no room for all those floorstanding same speakers with equal electronics/cabling all around. I imagine it would sound even better than what I have, which often is hard to imagine.

Thanks for the details!

Agree on RPG's positive influence in a room. I own already 96 :eek: Skylines, 8 4ft-Diffractals and 16 ProCorners from RPG. The later one is the only absorption product I used so far.

About your stereo experience I'm glad you mentioned some background because you never know with some HT guys :)

I'm even more happy that you say that you don't notice any influence in stereo by the big dead center. This is what I was told to... by the commercial fellows, never by someone who actually owns such a set. Therefor I appreciate your efforts.

Vinyl: Many years ago the steal all my LPs and more stuff. Since than only digital. Problem solved. :(

Regards, Rene
96 Skylines? Wow! I am envious. My comment about having a lot of diffussion seems incorrect now :o. I plan to add a lot more.

Rene-L, I have just been in my room listening to some music. I started with some SACD Getz/Gilberto and "The Girl from Ipanenma". My two channel imaging is the best it has ever been. Most of the track on this SACD sound like the vocals are dead center when they have been recored that way. Not all have been recorded that way. You would be convinced that the center channel is on but this is only a two channel recording. Then I tried some more vocals. "Over the Rainbow, http://www.amazon.com/Alone-in-World-Israel-Kamakawiwoole/dp/B00005O4UG . Again vocal dead center. Finally, I need a little excitement as IZ was putting me to sleep, so I then I switched to some old favorites, HARD ROCK:) AC/DC "Back In Black," a dual disk with enhanced PCM stereo on the DVD side. Finished off with some Ozzy, a more exciting one, Black Sabbats, "War Pig." Great song these days. I can not say how a large center will effect the sound of the speakers you will use. I am convinced it has no detrimental influence on my two channel.

Rene-L, I have just been in my room listening to some music. I started with some SACD Getz/Gilberto and "The Girl from Ipanenma". My two channel imaging is the best it has ever been. Most of the track on this SACD sound like the vocals are dead center when they have been recored that way. Not all have been recorded that way. You would be convinced that the center channel is on but this is only a two channel recording. Then I tried some more vocals. "Over the Rainbow, http://www.amazon.com/Alone-in-World-Israel-Kamakawiwoole/dp/B00005O4UG . Again vocal dead center. Finally, I need a little excitement as IZ was putting me to sleep, so I then I switched to some old favorites, HARD ROCK:) AC/DC "Back In Black," a dual disk with enhanced PCM stereo on the DVD side. Finished off with some Izzy, a more exciting one, Black Sabbats, "War Pig." Great song these days. I can not say how a large center will effect the sound of the speakers you will use. I am convinced it has no detrimental influence on my two channel.

If you are using a center channel which properly matches your front left and right speakers, and you are using proper setup including proper setup of your main front left and right speakers so you get a top notch phantom center image from them - and provided that your center speaker is at minimum the same distance from you as the main speakers (and possibly place the center up to 2-3 feet in back of that arc if you can as in some cases it may even give better sound) --
then the center should not detract at all. Of course, this also assumes that like me, center is on a stand, so it doesn't form a large rear screen tv projector size in the middle of your speakers.

I removed my center channel to make sure that it indeed was not restricting my two channel. My center is heavy and I have a hand truck that I use to move my speakers. Removing the center did not improve my set-up.

No problem Rene-L. I was curious myself and was already doing some work in the room. I copied the room that uses the Aerial 10T. Steve Bruzonsky is using 10Ts. I am using some Mcintosh speakers www.mcintoshlabs.com/data/Reviews/PerfectVisionDec02_LS360_CS350_PS112Review.pdf I have three of the LS360s across the front. I am using two CS350 at the rear and two WS350s not in the review on the sides. I have two Martin Logan Descent subs. Amps are Mcintosh MC501 monoblock on center, MC402 on L/R to soon be upgraded to two MC501s and two Mcintosh MC252 amps, one for sides and one for rears. I am using a Theta Casablanca III for movies and the robot-controlled analog pre-amp, the Six Shooter for music. Six Shooter has really pissed off a couple of my friends with tube pre-amps costing 5K and up. It beats their pre-amps and this is why they are angry:D.

I am waiting to see what Theta does with its replacement for the CBIII. I have two Superior II cards for the first six channels. I would like to run 8 channels with the Gen VIII on the front two. That is my ultimate goal. I am wondering if the new formats will dictate HDMI connections to the Gen VIII? I need to call Theta. I use a Sony SCD XA-9000 for music. CBIII is just for movies. Consensus seems to be that the best sound is with the Six shooter handling the pre-amp duties and the Gen VIII the DAC.

Rene-L where do you have those 96 RPG skylines placed? I am considering purchasing a lot more, soon. Found a deal on 24 more if I can work out shipping at a reasonable price.

Hey, where are you guys finding deals on skylines?

Chris I am a somewhat of a bargain hunter. I found a recording studio on L.A. that was going out of business. Perfect Skylines were 80.00 each, ones with small nicks 60 each and ones with broken towers 50.00 each. Afraid I have gobbled up the last of the best stuff. Only ones with maybe a broken tower or two left @ 50.00 each. Shipping is expensive because of the size. DHL was the cheapest. Rate to ship 4 from L.A. to New Orleans area about 80.00. Double that price with other companies.

gotcha! I've been thinking of making skylines myself. I've also considered making some QRD diffusors, but unfortunately I never took woodshop and have absolutely no woodworking skills whatsoever, nor the appropriate tools.

The QRD's are not nearly as effective as the Skylines. There are instructions for making copies of the Skylines. Man, just painting mine black was no easy task so making them is out of the question for me. I found QRDs, 2 feet by 4 feet on ebay for 50.00 each. I had to sand and paint them but they came out ok. Same thing, a closing recording studio.

i will use the EMM Labs Switchman III with a 'phantom center' option to allow my front speakers to simulate the center channel when there is center channel information. if i were to add a center channel equal to my front speakers it would clearly compromise the 2-channel performance acoustically.


I used Rives for a level 2 consultation on my room which I had designed to be optimized for two channel listening with surround sound added in to make it a movie room for my entire family as well (with a retracting electrical screen in the ceiling).

I'm currently using the B&W 802D speakers for my front left and right speakers and have been considering how to do a center channel, either a B&W HTM1D which is placed on the floor and is the size of the 802Ds (on their side) basically, or the HTM2D which is smaller but is on a stand. How much would something like the HTM1D compromise the 2-channel sound experience? What kind of effect would I notice on the two channel sound if I add the HTM1D into my setup for HT? Here are links for the 802D (http://www.bwspeakers.com/index.cfm/fuseaction/products.models/label/Model%20802D) and the HTM1D (http://www.bwspeakers.com/index.cfm/fuseaction/products.models/label/Model%20HTM1D), so you can get a sense of the proportions (the HTM1D lies directly on the floor). Here is the HTM2D (http://www.bwspeakers.com/index.cfm/fuseaction/products.models/label/Model%20HTM2D) which won't match the 802Ds exactly like the HTM1D will.

Oh, here is a link to the last concept drawing for the Rives designed room: Concept Drawing (http://www.jkalman.com/images/electrical.jpg).

I know I have the option of using a phantom center, but this might make the HT experience less enjoyable for my children, as I have three of them not everyone can sit in the on-axis center position.

Any advice is appreciated.

Thanks.

If you are using front projection in your theater, I would use an identical speaker behind an acoustically transparent screen. Anything else is a compromise.

I used Rives for a level 2 consultation on my room which I had designed to be optimized for two channel listening with surround sound added in to make it a movie room for my entire family as well (with a retracting electrical screen in the ceiling).

I'm currently using the B&W 802D speakers for my front left and right speakers and have been considering how to do a center channel, either a B&W HTM1D which is placed on the floor and is the size of the 802Ds (on their side) basically, or the HTM2D which is smaller but is on a stand. How much would something like the HTM1D compromise the 2-channel sound experience? What kind of effect would I notice on the two channel sound if I add the HTM1D into my setup for HT? Here are links for the 802D (http://www.bwspeakers.com/index.cfm/fuseaction/products.models/label/Model%20802D) and the HTM1D (http://www.bwspeakers.com/index.cfm/fuseaction/products.models/label/Model%20HTM1D), so you can get a sense of the proportions (the HTM1D lies directly on the floor). Here is the HTM2D (http://www.bwspeakers.com/index.cfm/fuseaction/products.models/label/Model%20HTM2D) which won't match the 802Ds exactly like the HTM1D will.

Oh, here is a link to the last concept drawing for the Rives designed room: Concept Drawing (http://www.jkalman.com/images/electrical.jpg).

I know I have the option of using a phantom center, but this might make the HT experience less enjoyable for my children, as I have three of them not everyone can sit in the on-axis center position.

Any advice is appreciated.

Thanks.

Queue,

first; congrats on the design and project; we'd love to see finished pictures.

if you are using your room as a theatre on a regular basis then a center channel speaker is quite important for dialogue with off center viewers. also; the smaller profile front speakers such as HTM1D or HTM2D will have less effect than a full size center channel matching your 802D's on 2-channel performance.

it is hard to generalize the effect of a center channel speaker on 2-channel performance. in less than ideal rooms there are many things going on with the wall behind the front 2 speakers. depending on those issues; a center channel may not 'screw things up' much more than what is already happening. as you optimize the diffusion of the wall behind the speakers and create the ideal enviroment for soundstaging anything that compromises that will have an 'effect'. this effect may be more some difference rather than 'good' or 'bad'. in my room with the large diffuser in the middle of the wall i can tell sonic differences between where i place my amps on the floor or even if someone is standing between my speakers. that diffuser simply allows for such a highly 'alive' field of sound.

it appears from your drawing that there is a similar large diffuser on your wall behind the speakers and projection screen......similar to mine. if that is correct then anything in that soundfield may have an adverse affect. it will be a matter of degree and whether it is just different or actually a detriment. hard to say precisely.

my prediction; based on my experience i would expect one of the small center channel speakers to slightly reduce the 'air' around instruments and maybe slightly reduce microdynamics. there may be a slight loss of focus in parts of the soundstage. these would be very subtle differences if you could hear them at all.

it would require critical listening to hear any difference.

my recommendation; get one of the smaller center channel speakers. it's small enough to A/B easily and then see for yourself whether there is enough of a difference for it to be removed at certain times. also; ask Richard or Chris from Rives what they think about your question.

Hi Queue,
I used Rives to design my room and we did our best to optimize for both 2 channel and HT. I had the same concern as you with respect to the center negatively impacting 2 channel performance. Rives said that teh best approach was to hang it from the ceiling because it would compromise 2 channel the least and would benefit HT the most - less sensitive to directional sounds above.

This ceiling configuration has worked really well, I don't notice any impact on 2 channel performance. I attached a custom made bracket to the ceiling to accommodate the center speaker (about 100 lbs).

Here are some photos of it and the room. Of note, I do remove the screen from the room when listening to 2 channel so that acoustics are not compromised. A bit of a hassle but I really don't like pull down screens. Sorry about the quality of the photos - quickly taken with a cheap camera

Without screen:

http://gallery.avsforum.com/data/501/wo_screen.jpg

With screen:
http://gallery.avsforum.com/data/501/front_wal_screenl.JPG

Back of room:
http://gallery.avsforum.com/data/501/rear_wall.JPG

I guess we should ask this guy about his full range center :) http://forum.audiogon.com/cgi-bin/fr.pl?vaslt&1135958151&read&3&4&

Oh, also note this guy is using Rives Parcs for 8 channels of equalization.

Thank you for the advice. Sorry I couldn't respond sooner, I was out of town.

Hey, where are you guys finding deals on skylines?
Man, have I found a deal on the same type of diffussers as the RPG skylines! The ones I have found are much bigger, 9 inches deep instead of 7 and 30 inches wide instead of the approx. 22.5 with of the Skyline. Build quality is excellent. They come already painted black with 8 coats of paint. I am waiting to get more in. The builder is using a DIY formula for these types of diffussers. His price is only 50.00 bucks each plus shipping. Shipping cost me 30.00 for about a 1200 mile trip. I have attached a photo of one. I need to take another photo next to a Skyline to show how much bigger this unit is. When you factor in how much more area you can cover with these vs the Skylines, the savings becomes even more evident.

Man, have I found a deal on the same type of diffussers as the RPG skylines! The ones I have found are much bigger, 9 inches deep instead of 7 and 30 inches wide instead of the approx. 22.5 with of the Skyline. Build quality is excellent. They come already painted black with 8 coats of paint. I am waiting to get more in. The builder is using a DIY formula for these types of diffussers. His price is only 50.00 bucks each plus shipping. Shipping cost me 30.00 for about a 1200 mile trip. I have attached a photo of one. I need to take another photo next to a Skyline to show how much bigger this unit is. When you factor in how much more area you can cover with these vs the Skylines, the savings becomes even more evident.

Interesting, great find. Can you provide the source? Made out of the same material as the Skyline?

Yes, made out of the same material as Skylines but bigger. The Skylines towers are smaller as well. Where the Skyline will have two towers with only a slight difference in height, this guy's diffusser appears to have the towers of the same height. His design though is deeper. I do not know how much of a difference in performance this will makes. Considering that it is still more complex that an RPG QRD diffusser, the results should be good. I am going to give the guy a little time before I refer anyone to him. He wants to build up his inventory. I believe that he plans to build a website as well. I attached some pics compared to my skylines. I have touch up the paint on this one. Painting them is difficult.

Yes, made out of the same material as Skylines but bigger. The Skylines towers are smaller as well. Where the Skyline will have two towers with only a slight difference in height, this guy's diffusser appears to have the towers of the same height. His design though is deeper. I do not know how much of a difference in performance this will makes. Considering that it is still more complex that an RPG QRD diffusser, the results should be good. I am going to give the guy a little time before I refer anyone to him. He wants to build up his inventory. I believe that he plans to build a website as well. I attached some pics compared to my skylines. I have touch up the paint on this one. Painting them is difficult.

He may not want to be too public with this - RPG might go after him if patents are involved. Please keep me in the loop. Thanks.

It's legit. RPG did not invent this type of diffuser. I saw the formula a couple of times. Bob Gold I believe has built some. It is not a copy of the Skyline. He's sending me two more this week. I should have 4 up soon. I plan to cover my front wall with as many as possible.

Here's the link. Hey I am all for DIY but this is too much work. 50.00 and painted too so I will let my source build them. http://www.bobgolds.com/DifuserKgveteran/home.htm

It's legit. RPG did not invent this type of diffuser. I saw the formula a couple of times. Bob Gold I believe has built some. It is not a copy of the Skyline. He's sending me two more this week. I should have 4 up soon. I plan to cover my front wall with as many as possible.

Good to know. Has he simply followe a known and sucessful formula? This would be very important as I assume that he hasn't tested them from a performance perspective, correct?

Correct.

This is a key question, is he using a QRD sequence formula? The ones on the Bob Golds are just random heights that don't have any mathematical relationships(AFAIK). Is he just using random heights, or actually building off a QRD sequence?

I don't think anyone can patent a mathematical sequence, but who knows.

You most certainly can patent the application of math to the design of optimal diffusors. Simple search of US Patent Office for quadratic residue diffusor reveals this...(actually a PRD but it references the QRD patent)

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-adv.htm&r=1&f=G&l=50&d=PTXT&S1=%22quadratic+residue+diffusor%22&OS=

Someone selling a 2D QRD/PRD would be infringing on these patent - which is why everyone else must use a different sequence. Of course you can DIY - since a patent is supposed to be instruction to those suitably skilled in the art - you just cannot sell it without a license.

Certainly RPG did the research on which mathematical sequences had optimal diffusion - they had to research how to simulate diffusion patterns as well as define what was optimal. The result of that was finding optimal patterns - which they patented for discovering them. They are not patenting the sequence - they are patenting diffusors that use that sequence. Without the patent opportunity they never would have funded the R&D. Why invest in product design if your competitors can knock it off for cheap since they get the design for free?

That's why I'd be a terrible patent attorney. :)

Hello all, just lurking here doing some reading and thought I would add this info for anyone interested in DIY difffusors.

http://www.mhsoft.nl/user/ac.asp

My room is getting very close to completion. I pray I don't have a heart attack in the next two weeks before it is officially finished. That would be the ultimate irony... The room is finally finished and only my wife and kids are around to use the room because I'm dead. Guess I didn't need those locking doors after all. I need to make a cardboard cut-out of myself that they can place in the room in case anything happens to me. It would also be nice to have the cardboard cut-out to scare off anyone who tries to break in and steal equipment.

Of course, it isn't finished even once it is built. Then it is time to do ETF measurements and make minor adjustments to the room and speaker positioning where necessary in order to flatten the frequency response further. Oh, will these good times never end? ;)

I got my skylines and absorbers yesterday and they look great. The skylines do need some touching up though, but RPG was more than happy to send me the acrylic paint that was left over from my special order so I could touch them up before hanging them on the ceiling.

Wow Que, I just checked out your thread, your room is really coming along nicely :) . On the resonator, is it more of a broadband resonator or is it more frequency range specific according to your room and equipment?

Has anyone used the lower profile skyline diffusors?

Wow Que, I just checked out your thread, your room is really coming along nicely :) . On the resonator, is it more of a broadband resonator or is it more frequency range specific according to your room and equipment?

I'm not sure. The dimensions on the passive resonator are around 10' long or so and 1.5' or so depth at the center. My room width is around 18' and the length is about 33'. Perhaps you can tell me! I'll ask Richard Rives during the next consultation (likely after the room is finished and it is time to fine tune).

I don' know how equipment specific it could be since I currently have B&W 802Ds for my stereo speakers but will likely have Revel Ultima2 Salon2s by the end of the year some time. When I asked Richard Rives if the Salon2s would work in this room setup he said, yes. I would guess that it is because they have the same general footprint and dispersion (despite the different number of drivers). Does this help to identify the passive resonator as broadband or frequency range specific? I guess not, since his statement didn't reveal what aspects of the room he was referring to that would be effected by a speaker that didn't fit the design criteria... It does however tell us that I might have some kickass speakers by the end of the year! :p

RPG did not invent this type of diffuser. I saw the formula a couple of times.

A local artist I know created a diffuser like this for himself out of many, many little tiny chairs of varying height. Took him months and almost drove him crazy but it sure is an novel idea.

Here's a link:
http://jamesshefik.artist-at-large.com/mix.htm

Click on the upper left picture.

A local artist I know created a diffuser like this for himself out of many, many little tiny chairs of varying height. Took him months and almost drove him crazy but it sure is an novel idea.

Here's a link:
http://jamesshefik.artist-at-large.com/mix.htm

Click on the upper left picture.

That is one beautiful piece of artwork! I doubt it would work correctly though, since the geometric shapes are not solid, unless somehow he took this into account (the mathematical implications of which would be staggering and could probably be used as a PhD thesis).

Is he just using random heights, or actually building off a QRD sequence?

I don't think anyone can patent a mathematical sequence, but who knows.
He is building off a mathematical sequence. It's been a few years since I have considered this. At the time, the formula was being widely discussed http://homerecording.com/bbs/showthread.php?t=71858 . I seem to recall the BBC publishing the formula that everyone was using. Bob's not your average run of the mill DIY. He's very advanced in regards to acoustics,very. Skylines are great. I just don't think you can really have a great room without diffusion. That's just my opinion of course. My room was lifeless with just fiberglass absorption. IMO fiberglass absorption alone makes the room sound much worse if like the majority of guys around here you intend to use the room for both movies and music.

Keep me in the loop, I'd be interested in a couple of these probably, depending on how deep they are.

For stereo music alone some absorption was better than no absorption in my room before all this work started. I had terrible slap echo issues and the absorption panels I made for myself helped with that tremendously. The direct reflection issues were also a problem causing a lack of localization in terms of the stereo imaging, which the absorption panels helped with as well. I'm not sure what they would have done to the sound of movies and/or surround sound though because at that time I was only using it for two channel listening...

Hi Thunder,

I just realized you were also in Ontario. I'm in the process of getting Rives to do a level 3 room for me.

Nice setup, love the PMC speakers. Considered them but going with full ATC which are quite similar.

I've PMed you.

The Bogg in Richmond Hill

Thunder,
sorry for the duplicate PMs, had some issues with the AVS website.

Keep me in the loop, I'd be interested in a couple of these probably, depending on how deep they are.
The are 9 inches deep. Ethan Winer of real traps once told me that the simple way to test a diffuser of this type was to speak into it. When you do, you can hear your voice being diffused. These diffusers pass that simple test. Guy is building more and I'll pass his information as soon as he give me the go ahead. He is a bit slow, a lot of work, but I am not complaining for what I am getting for the price.

You guys with the Rives rooms all have great looking rooms.

You guys with the Rives rooms all have great looking rooms.

I wish I could have built mine from scratch doing a level 3 like Mike did in his converted barn space (well, I wish I cold have a lot of the things Mike has in his room, including those speakers, without my wife castrating me... :D). Still, I'm optimistic my HT/Listening room is going to look good when it is done, despite the dark colors which were necessary since it is also a HT as well as a two channel listening room. I'm curious to see how the ETF measurements turn out, but I won't bother completing the level 2 fine tuning/adjustment phase of the room construction until I upgrade the speakers to the Revels, or decide not to upgrade.

When my kids are older and move out, then maybe my wife and I will move to another house and I can build something from the ground up. This room will have to work for the next 16 or so years until then I guess because my wife isn't willing to budge from our current location... :o