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Hi Al, " I could turn up the center channel volume, but that would screw up the stereo image big-time! " As I recall you are using the PWK minibox for your center? If that is the case turning up the center will mess up your imaging since the center is receiving a full mono mixdown so hard left and hard right will still be coming out of the center. With other approaches that wouldn't be the case. Those approaches can remove the centrally imaged (mono) material out of the L/R speakers and move it physically to your center channel while leaving hard left and hard right alone. Since it will image from front and center... why not reproduce it from front and center and reduce the dual mono comb filtering between multiple speakers and increase image stability. In these setups (when done well) your imaging is strongly enhanced, not screwed up. You have a real speaker reproducing the most critical elements (vocals front and center) and you now have imaging between three speakers instead of 2. Instead of trying to image between 2 speakers 18 feet apart you are in essence imaging between speakers 9 feet apart. Shawn

Hi Dean, How are you enjoying the coaxials? Still having fun with your system? Shawn

Hi Dean, Yeah sorry, lot went on in the last year or so. Recovering from a hernia operation so for the next week and a half I have a lot of time to kill. Shawn

Peter, Checked your profile.... one fairly easy way you can test the mono on stereo vs. mono on single speaker is to play back a mono source through your AVR 254 and switch it between Stereo and DPLIIx or Logic 7. Either PLIIx or Logic 7 will steer the mono material out of your K'Horns and put it into your LaScala center. Logic 7 Movie will likely have a little bit stronger steering the Logic 7 Music and if the H/K gives you the options PLIIx should have a Center Width setting which allows you to adjust the strength of the steering. Your center isn't an exact match to your L/R so that will influence the results a bit but you should still be able to hear the changes. The other thing you can of course do is spend a week or two listening to music in either of those two modes. They will leave L material in L and R in R but with still steer mono material to your Center. At first it will sound very different... give it time.You might be surprised what can happen after you get accustomed to it. Shawn

"I'll admit that I haven't. That would be a good test to see whether I can hear comb filtering." Give it a shot sometime. I think you will find that the image is obviously far more stable, and vocals will have more body/weight and less phasiness to them. They will sound more real. In the real world we always hear vocals from a single point source, not dual mono from two sources. The other test to hear comb filtering easily is to play pink noise through 2 speakers. Move around (horizontally and verticaly) and listen to how the sound changes. Do the same thing with 1 speaker and see if the sound changes to the same degree. For those running actives up the slope and see what effect that has. Shawn

"but on the other hand I love the sound of my two Klipschorns even when they are fed a mono signal. " Have you spent much time comparing the pair fed mono vs. a single one fed mono? Esp. on something with strong vocals? Shawn

Happiness......

I'm 6'5" and fit. Easy to get in and out of the doors open wide. There is a styrofoam hump behind the seats that can be removed to allow you to recline the seat slightly more which helps.http://www.waycoolinc.com/z3/02/100602/shish09.html Tightest part is simply the tops frame when it is up. If you are tall avoid the later cars with lined tops (less headroom) and avoid the M Roadsters as the seats as taller which again gives less headroom. A few guys removed the power seat mechnism from the seats and bolted the seats directly to the floor. This gives a few more inches of clearance but I never bothered to do that. Shawn

The rollbar in my car above is a HMS Motorsport rollbar. They aren't showing up on their site anymore so I don't know if they still make them or not. Another option is the Hard Dog roll bar. http://www.bethania-garage.com/z3.htm which looks like it is pretty similar to the HMS bar. Shawn

"BMW does not make just a nice care they make a pretty safe one." Yes they do. My wife had an E46. When my daughter was 10 months old a full size van with wheelchair lift (HEAVY) ran a red light at about 40 miles an hour. She hit us right at the back edge of the driver side rear door. It spun us around 180 degrees and ripped the rear tires off the wheels. My daughter was in a car seat in the back seat. I jumped out of the car and the rear door still opened, no glass was broken. My daughter was scared but fine. Very glad we were in that car that day.... Shawn

Rplace, Ouch, sorry about that. The Z3s are very tough in accidents. Lots of accident pictures at: http://z3ers.com/accidents/accidents.html Some are really mangeled front and rear but the passenger compartment is still basically untouched... just what you want to happen. Shawn

"nor a passenger airbag" All Z3s have passenger airbags. You can retrofit roll hoops if desired and there are aftermarket rollbars too. Shawn

"Yes it's a bit of girly color..." Atlanta Blue... it was good enough for 007. You will have fun on Thursday...... Shawn

The biggest thing to have checked out is the rear subframe at the diff mounts and the spot welds in the trunk. There have been some cases of the subframe cracking on Z3s. It is mostly an issue on hard driven cars but can occur on any of them. If this one is having those problems skip it, there are others. Other common problems are the rear shock mounts going. I went through about 3 sets of factory mounts and 2 sets of aftermarket before I found a pair that held up. Relatively easy to DIY if you are so inclined. See if you can get a maintenance history on the car. On the sixes they tended to need cam sensors replaced. Other then those things they are solid cars. Z3s are a *blast* to drive. Shawn

" My room is sort of hatchet shaped. A hall enters one corner that is about 18 feet long. " Is that hallway sealed off? If not you won't see very much room gain there since that hallway is extending the longest dimension of your room. What room gain is where the reflections from your walls are becoming more and more in phase with the sound still coming out of your subwoofer(s). The sound couples and you get an increase in SPL throughout the room. Basically the area where you entire room is turning into a mode. You won't get say 6dB increase in output for 10-80hz. What one could get is say 0dB from 80-40hz, then a second order increase from there down. In other words a curve that would give you +12dB at 20hz, +24dB at 10hz...etc. But that would be perfect room gain which won't happen if you are leaking bass. You have to overlay the room gains curve over the response curve of your speakers. So for example if your speakers are ported (or horn loaded) they roll off fourth order. So if they happened to start rolling off where the room gain kicks in (40 hz in this example) instead of your acoustic response being down 24dB at 20hz you would only be down 12dB. Instead of being down 48dB at 10hz you would be down 24dB. The real trick with room gain is to make your subs response be the inverse response of room gain. In other words have them rolling off second order at the same place as your room gain kicks in. If you do this you can keep your subs flatter longer without trading additional bandwidth for output as one would if they tried to EQ the subs flatter. Since room gain is second order you need a sub that rolls off second order... a sealed design. My rooms longest dimension is 17' so room gain should be kicking in at about 32hz. The room has no windows, has double drywall walls and ceiling all screwed and glued on its own interior studs and a concrete floor. The door is all sealed up. It is a solid room that leaks bass much less the most rooms. My L/R subs are 6 cubic foot sealed cabinets each with 2 JBL Sub1500s in them. The f3 of these are about 33hz with a !0.5. So in other words they naturally are rolling off to be down 3dB at 33hz and follow a typical second order rolloff. At 16hz in free space they would be down 12dB. However in room the room gain keeps them flat to at least 10hz. Possibly lower but the measurement equipment I used stops at 10hz. My LFE sub is ported (passive radiators) with a natural f3 of 14hz. It rolls off fourth order though so on the really deep stuff my impression is that the sealed subs actually go deeper in room even though their designed f3 is about 33hz. The room gain matches the rolloff of the sealed woofers, in only cuts the rolloff of the ported woofer in half. "I need to reproduce the low bass effects I hear in movie theaters." That is not a good goal. There is far more bass effects on DVD/BluRays then most movie theaters can really handle. Good home theater isn't about trying to match a movie theater, but to exceed it. What is the target SPL you want to be able to hit? If you listen at THX Reference level the LFE channel can hit 115dB at the listening position. Shawn

" Room gain is said to be +6 dB. " Room gain is basically a second order (12dB/octave) increase in bass from the point it begins at. Where it starts kicking in totally depends upon the dimensions of the room. Basically it starts at the half wavelength of your rooms largest dimension. So in a 17' room you will start seeing room gain at about 32hz. That is assuming a well sealed room, the more lossy/leaky your room the less boost you will see in the bass. Shawn

There is much more then just the Dope from Hope papers in that PDF. Shawn

http://rapidshare.com/files/211934220/THE_PAPER.pdf.html Will work for only 10 downloads I think.... Shawn

Someone did this years ago on the forum. Shawn

Dave, "Where v=vinyl and d=digital, if v=d, then it only follows that d=v. In other words, an LP mastered from the digital copy of the LP that no one could distinguish from the vinyl would also have to be indistinguishable from either the vinyl or the digital copy. I hope I structured that right." Nope, that is a logical fallacy A = CAR B = Honda Civic B = A (Honda Civic is a CAR) but is the inverse true... does A = B? Nope, not all cars are Honda Civics. To try and boil this down simply.... Digital is transparent, figure it is adding +0 every time you transfer to it. Vinyl adds its own sound on playback, figure it as adding +1 every time you transfer to it. Take a master give it a starting number of say 10. Put it on vinyl 10 + 1 = 11 Put it on digital 10 + 0 = 10 Take the vinyl made from the master (11). Put it on digital 11 + 0 = 11 Take that digital copy of the vinyl and put it back on new vinyl 11 + 1 = 12 Shawn

Dave, "I don't know what you mean by "mono rear." The rears were quite separate and the feeds discrete" The basic Hafler extracts a single rear channel of information. Hafler was simply L,R, L+R (center) and L-R (rear). See: http://sound.westhost.com/project18.htm For several different ways of implementing a Hafler setup. The original way is shown by connecting a third speaker to the positive of the L and R speaker. Only out of phase material would be reproduced by it. DynaQuad may do something differently but up till now you have been saying Hafler which is what I was referring to. "my take on surround from 2 is that the image widens and deepens, far more like a real experience." As is mine. We are using different approaches but doing it for the same reason. A more real sounding listening experience. Have fun, Shawn

Jim, "I used Trifield in a 2 ch system for some time and was always amazed at the results, I'd swear there was a center channel where there was none." I've never tried Trifield with a Meridian configured for just 2 speakers. I'll have to try that some time. Trifield really shines up front when you add a center to the mix. "In the end, I was too ADD to use the Meridian processor as I was always trying different surround effects and then comparing those to stereo," That can be a problem. I ran into that when I first started toying with music in surround. The Fosgate's I had had modes that sounded great on music some of the time, but also lousy some of the time and decent the rest of the time. I kept bouncing around between modes/settings trying to find something that worked consistantly well. I ended up just sticking with stereo then but kept an eye on surround. Eventually I got equipment that sounded great a very large percentage of the time so now after I had the system dialed in I can just leave it alone and let it do its thing while sounding great. Shawn

"..because the earlier Dolby PL didn't do as good a job." No, it did lousy on music... everything collapsed into the center and it tended to be unstable with pumping/breathing. When you did Hafler were you doing that at speaker level? If so that would be tough to integrate with other processing. "I'd love to hear those sometime. I guess I am just skeptical that they could do a better job than Hafler on 2 channel native material." If you liked Hafler that much there are numerous products that did that at line level. Should be pretty easy to integrate that into your existing setup. For example a Dolby Surround decoder (not Dolby Pro Logic) is basically just Hafler passive with the addition of a 7kHz low pass on the rear channel to make Hafler's very low channel separation F/R less distracting. They might also add delay for the rear channel again to reduce the distraction by taking advantage of the precedence effect. There are lots of other products that implement variations of Hafler too, I can send you a Fosgate if you wanted to try it at line level with delay for the surround channel. If you are ever up my way you are welcome to come and hear the other modes and to compare that to Hafler. IMO Hafler is decent but doesn't compare to the others. Its single mono rear channel can't properly surround you with a halls ambiance. A halls reverb is not corollated, the mono rear of Hafler of course is and doesn't sound as natural or nearly as open as some of the other methods. The lack of steering means there are no steering errors but in turn it means it can't pull material out of L/R and move it to where it would try to image from anyway. For example front and center vocals can't move front and center to reduce the comb filtering between L/R which is not natural. FWIW Trifield does not use steering either but works on a totally different principal then Hafler up front. Its rear channels are closer to a Hafler matrix though. Shawn

" I'll second Meridians Trifield, the best I've heard and the only which would consistently steal me away from 2 ch." Trifield has converted a lot of 2 channel guys into surround converts. It does a nice job, esp. up front. The actual process of expansion was designed for any number of front channel speakers. It would be very interesting to hear it used for >3 speakers but I don't think anything has ever implemented that into a product. I have L7, PLII/PLIIx and Trifield available in my system. Shawn

Dave, "I quit when I get something that precisely what needs to be done, no more, no less. " Nahh, otherwise you wouldn't have moved on from Hafler. " logic suggests those units would not be able to do any better in the circumstances I mentioned than DPLII. " You should listen to them sometime, they all work on different principles (esp. Trifield) and they do sound different. Shawn