rplace Posted July 18, 2005 Share Posted July 18, 2005 Is this possible or am I going crazy? Perhaps my ears are getting used to the imaging/sound stage of my speakers??? It seems to me I have lost the ability of my khorns to produce a centered image. When I first got them I would swear my center channel for HT was running I would literally check the other amp and put my ear to the center speaker to make sure there was no sound coming form it. Now that appears to be lost. Recent changes include a Niles switch box to allow me to run my Scott 222C or my Sunfire solid state equipment. I have also added some broad band acoustical treatments to the room. I have checked and rechecked the wiring and disconnected the Niles box altogether. When I use an Avia or Sound and Vision test disc I would swear allnot just my front mains are out of phase. Yes ever set R/L, Center/Left and surrounds seem to be out of phase. If I swap the + and wires they still sound the sameno center image and out of phase with phase test. What do I do next? Quote Link to comment Share on other sites More sharing options...
DrWho Posted July 18, 2005 Share Posted July 18, 2005 Stop listening to music for a day and come back tomorrow...trying to enjoy the music. If it still sounds off, then I would start troubleshooting one thing at a time. Quote Link to comment Share on other sites More sharing options...
leok Posted July 18, 2005 Share Posted July 18, 2005 Could it be your listening position is not centered? If you're not sure, get a tape measure and check. Your listening position should be the same distance from both speakers. A small shift can sometimes make a very big difference. Leo Quote Link to comment Share on other sites More sharing options...
rplace Posted July 18, 2005 Author Share Posted July 18, 2005 Dr. W, I did think of that...so I gave up and came back the next day. Same thing. I have noticed for say a few weeks that the appearance of a center image is missing. I just had not taken the time to throw in the disc and give it a phase check. Leo, I am in the same listening position I have always been in. Part of my trouble shooting was to measure the distance and make sure the values had not chanced in my A/V Pre/Pro set up. The real issues is with listening to music in 2-channel. Makes no difference if it is CDs through the solid state gear or LPs via the TTable and Scott Tube gear. There is just no sound stage or center sounding vocals or anything else. Strange. Quote Link to comment Share on other sites More sharing options...
3dzapper Posted July 18, 2005 Share Posted July 18, 2005 I have observed the phenom you are experiencing more than once. The Khorns sound comes from the speakers, not the soundstage. Switch the wires to one Khorn. If the image returns you have it nailed. I have a couple of amps that for whatever reason I have to swap leads. There is no real plus or minus with AC waveforms. Just correct and incorrect. So it does not matter where the red wire or black wire goes. As long as they aren't shorted that is. Quote Link to comment Share on other sites More sharing options...
rplace Posted July 18, 2005 Author Share Posted July 18, 2005 3d, I have actually swapped one khorn +/- then both, so in essence I have tried; both "correct", one wrong one right and both wrong. Same results. What I find really interesting is that if I forget about just 2 channel (which is the problem I set out to correct) and try the phase test on all my speakers they all sound out of phase. I even used two different discs for checking phase. Quote Link to comment Share on other sites More sharing options...
DrWho Posted July 18, 2005 Share Posted July 18, 2005 I would try simplifying your setup, perhaps starting with the Niles switch box and keep taking things in and out of the chain until you find the culprit. Is the bass response there? Quote Link to comment Share on other sites More sharing options...
rplace Posted July 18, 2005 Author Share Posted July 18, 2005 Dr. W, Yes the bass is there. Why do you ask? It is actually better (real or in my mind) since I added the room treatments. As for the Niles box...that was my first suspect. I have tried taking that out of the mix and directly hooked the khorns to my solid state equipment. It is not practical in my room to hook the Scott up directly. In its simplest form a few months ago I was running just the solid state equipment and CDs to the khorns and the appearance of voices/music directly from the center was amazing. Now it is nonexistent. Things that have changed since then: 1. Added tube gear and Niles switch box 2. Room treatments so far absorption mostly on side wall and corners. No diffusion yet 3. Different Turn Table (Thorens was replaced by a Music Hall) I really cant pinpoint when the imaging was lost but I know it was there with just solid state gear and CDs in the March to May timeframe. So I have tried to recreate that set up by removing the Niles box. I can tell you I am pretty sure it is not the room treatments because looking back I believe the imaging has been missing form my listening for several weeks now. I did the room treatments a week ago. The turn table/cart is not an issue when I take the Niles box out and run SS gear only as the TT can only be run with the tube gear. It is really puzzling me. The biggest puzzle of all is the other speakers seeming to be out of phase as well. I know when I first set up the theater environment I did phase check on all speakers (L/R, L/Center and surrounds) they were all fine. Now none are. Hmmm, thinking as I type. I did just go from 6.1 to 7.1 with two more heresies replacing my single Chorus for surround backs. Is it possible that the pre/pro is matrixing the back signals and causing the appearance out of phase just for the surrounds? Sorry for the home theater stuff in 2 channel but it really is the 2 channel listening that I am most concerned with right now. The rest of the apparent phase problems came as a result of checking the left/right channel. Is it at all possible that is it my Sunfire Pre/Pro. If so how/what do I check??? Surely it cant just change on me over time. Quote Link to comment Share on other sites More sharing options...
dragonfyr Posted July 18, 2005 Share Posted July 18, 2005 Just a couple of comments... One, the terms phase and polarity are being confused. Two, despite the opinions in another parallel thread, there is a 'correct' and an 'incorrect' polarity. Impulse responses do not lead with the regression of the dynamic transducer. And there is a difference in the potential and kinetic energy of the system. And easy illustration of this is provided by the Nyquist and Heyser spirals. Third, I would suggest the switchbox as a primary cultprit for polarity issues. Additional phase issues if the impedance has been altered via capacitors or inductors - as i have no idea what is used to compensate for different loads in that thing as I don't use them. Forth, you mention you have changed the wall treatment. I actually might suspect this depending on how and why it has been done. If it has been done simply based upon the perceived need that it must be done without respect to actual measured responses, there is NO way to ascertain what effect this has (let alone to what it was done to correct!). Especially as you mention that only absorption has been used! Simply adding absorption &/or diffusion does not imply correction. Thus the value of time based measurements. There is a very good chance that you have modified the 'balance' of the various signals thus creating an anomalous Henry precedence effect (incorrectly referred to as the Haas effect after someone who rediscovered the effect almost 100 years after Henry documented it!). This and other heretofore undiscernable/undescribed effects could most definately change the perceived imaging. Lots of variables, with too many things being changed simultaneously to allow us to properly isolate and ascertain the cause of what is admittedly an unclear effect. DoctorWho is indeed correct in this regard. Maybe you need some of those fancy 'through the wall cables' being discussed in the other thread! Quote Link to comment Share on other sites More sharing options...
D-MAN Posted July 18, 2005 Share Posted July 18, 2005 2 things that I can think of... if you are 100% sure that the wiring to the Khorns is correct... 1) take the switch box out of the circuit and listen to the tube gear alone. If it is still "non-imaging" then go to step 2. I would question the switch box (but that's just me). 2) take the tube gear out of the circuit and go back what you used before the tube gear. If it is still "out" then the room is the issue. It is not probable that the tube gear is the problem, unless wired incorrectly, as they may provide a different soundstage, but it will not be so totally different that your room treatments will become totally ineffective. That is to say, if your room USED to sound good before you did all of this, it probably STILL IS good. It sounds like some other problem to me, and with all that gear (and its attendent wiring) being changed out, a polarity issue could be the natural result. It's easy to fix but could be hard to track down. So approaching the task one at a time is the best approach, and removing one variable at a time is the way to go. DM Quote Link to comment Share on other sites More sharing options...
rplace Posted July 18, 2005 Author Share Posted July 18, 2005 So what is the correct term, phase or polarity, so I can use it? The two discs I am using to test with both call it a phase test. Where you hear noise that is for some time easy to detect where it appears to be coming form then for a brief time it appears hard to determine where it is coming from. The fix if they are "out of phase" is to switch the + and - speaker wires (or black and red depending on your point of view) for the right speaker only. I have seen speaker wire with two different strand colors (copper and silver), same color of strands with + and - markings and the same color of strands but different colors (black and red) of insulation. Correct me if I am wrong but I can't believe there is any difference in the actual strands of wire used. These are just different way of helping you get the correct wire to the correct terminal of the speaker and amp. Black wires to black terminals and red wires to red terminals or +s to +s and -s to -s, right? D-man, The wires to the back of the khorns have not changed because I have not pulled them out of the corners and the wires run through the walls. It is only me an my wife...no chance they were switched in the past several weeks. I have checked and rechecked on the amp end of things when not using the switch box and on the switch box when using it. I will do it all again tonight. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted July 18, 2005 Share Posted July 18, 2005 I agree with one of the Dragon's points. I'll bet you over-damped the room with either too much or maybe incorrectly applied acoustical treatments (just guessing , and you obscurred your stereo image. It sounds like you checked and rechecked all your connections over and over to the point of "going back to the same places over again to find your lost keys". The image shouldn't just go away one day. I'm guessing, but I bet it's the room treatments. If you went the glue route, then it may be a difficult task to try moving or removing the treatments temporarily. Good luck Let us know what fixes it. Quote Link to comment Share on other sites More sharing options...
DrWho Posted July 18, 2005 Share Posted July 18, 2005 Phase refers to the relative position on the wave form (picture a sine wave) eminating from two sources. If two sources are playing the same tone, but one is at the peak while the other is at the trough, then they are 180 degrees out of phase and will cancel each other out. Polarity refers to the direction the speaker diaphragm is moving, basically which direction a positive voltage moves things. Two speakers can have the same polarity, but be out of phase due to their physical location. The fact that you have solid bass indicates that your speakers are in phase and so you shouldn't bother with any more tests like that... Do you have any equipment with a small plug that can be inserted into the wall both ways? I would start by swapping one piece of equipment at a time and see if you notice any changes. After that, I would swap the polarity on both of your mains (so instead of swapping one and reversing the polarity, swap both of them at the same time). These would be testing for absolute polarity, which is being discussed in the technical questions forum. I'm also beginning to suspect that your treatments might be the issue as well. Do you still have your cd player and SS amp laying around? I would plug it in exactly how you had it when you were enjoying it and if you can't get that sound back, then you probably will want to start ripping down that treatment. Hopefully you have it setup so that it's mostly temporary. Since I don't have the fancy toys, I usually spend a few weeks tweaking the locations until I can decipher what changes are happening and then go from there. I bet your sidewall treatments are the culprit. just to get an idea of your situation, what are your room dimenstions and what treatments have you employed already? Quote Link to comment Share on other sites More sharing options...
dragonfyr Posted July 18, 2005 Share Posted July 18, 2005 Well, I have a few .pdfs that explain both the polarity issue as well as the image shift issue but as the site does not support uploading the files, I suppose the issue is moot. How about a thread regarding the continuing INABILITY to resolve the simple issue of uploading a file to this site....Maybe they just need some of them fancy 'through the wall' cables. Quote Link to comment Share on other sites More sharing options...
rplace Posted July 18, 2005 Author Share Posted July 18, 2005 Room dimensions are more or less a rectangle of 13.5 feet (khorn wall) by 16.75 feet. There is small 3X3 foot alcove in one back corner and an angled ceiling where my basement steps come down in the other back corner. Ceiling is almost, but not quite 8 feet high. Along one side wall I have a double set of French doors. I devised a removable contraption to block the light from the 30 small windows in the two doors. It is hardboard (brown pegboard stuff with no holes) with foam panels glued on to the hardboard. Each door holds one panel. Each panel is 2 feet wide by 6 feet high. These block the light and hopefully improve the reflections from the glass along that wall. On the opposite wall I have 10 1X1 foot foam panels arranged in a sort of diamond pattern. I put 3 2X2 foot panels on the ceiling in a V pattern much like you see on many rooms. I have also put a 6 border of foam along the front wall where it meets the ceiling and a good portion of the side walls where they meet the ceiling. I also put foam cubes in the two front corners. Ill try and take/post some pix of the room treatments when I can. At any rate I can remove the treatments from the doors very, very easily. Not so easy on the other wall. I am 99.33333% sure that I had lost this nice imaging in the center of the room BEFORE I put up the room treatments. I had added the Scott amp turntable combination and been running wires across the floor for several weeks when I noticed it. I assumed I had a wire wrong on the Scott and had just not gotten to it. After all I have been listening to a lot of mono Jazz albums, so when I did listen to stereo (yes I switched the mono/stereo switch on the Scott) It was just not high on my list of things to look into. Anyway this weekend I decided to get it tracked down but did not have much luck. Then I decided to get rid of the Niles and the tube gear all together to get back to just Solid State gear with CDs which is the first incarnation of my room when I got the khorns earlier this year. Still no luck. Quote Link to comment Share on other sites More sharing options...
leok Posted July 18, 2005 Share Posted July 18, 2005 rplace, I realize this may not be the issue, but you might want to be very sure before you spend a lot of time on other non-issues. The room treatment part of this makes me think that reflections that used to part of what you hear, are reduced. That means sound, directly from the speakers is a greater part of what you hear, and if the distance from each speaker to the listening position is off by just a few inches, there will be phase cancellation of some frequencies in the center of the soundstage. With more reflected sound you get a more difuse source that is less position critical. By removing those reflections you may have uncovered the fact that your listening position is not exactly centered. I recommend you measure the distance to the same point on each speaker to your listening position. I had exactly this problem with my RF-7s. The layout in my office made it look like what was a central position really wasn't. Finally I resorted to a tape measure and found the problem. Also, if you can get one, various audio test disks have tracks to help solve the problem you are having, whatever it is. Good luck Leo Quote Link to comment Share on other sites More sharing options...
dragonfyr Posted July 18, 2005 Share Posted July 18, 2005 With all due respect, there is no way to effectively troubleshoot a time domain issue effectively by a very simple description of a room. As much as I sincerely wish it were.... The problem is in the fact that you are dealing with a magnificently complex non-linear system! The absorption you placed is VERY frequency dependent, and the relative intensity and composition of the reflected signals are critical. ...Meaning that there are many orders of reflections, each with frequency dependent reflective surfaces, and they must be treated in total and not haphazardly or independently of each other. For instance, if you still have prominent focused reflections from the rear surface and you have removed other near field reflections, the relative levels and differences in delay within the overall total response structure can induce some rather weird anomalies - the sonic equivalent of visual optical illusions. And overall, the goal is not so much absorption, although this is a very powerful tool when used 'surgically', but rather difussion. But still, the energy that is diffused must be done in a well behaved manner. Simple diffusion of everything is the partner to absorbing everything. And the result will not be pretty. And the TOTAL response structure is the goal, not simply isolating and eliminating a few low order reflections as is SO OFTEN suggested. The difficulty here is in attempting to draw any specific conclusions, as ANYTHING might be possible! There is a systematic way to do this, given the proper information and feedback which shows the effect of the modifications on the overall response, but my general suggestions to the forum is that simply buying off the shelf kits is a hit or miss proposition, And it may indeed change the overall response, but it more likely will simply move the problems around. But there are more optimal ways to accomplish this! I guess what is a little more frustrating is that for every suggestion made, assurances are made that it is probably not that aspect. OK..., so to be a smart aleck, if this is so, then I guess the problem is solved, as it was fine before the changes, and none of the changes caused a problem. oh well..... ------------- And to stand back for a minute, I find it humorous that in one thread I yell for the value of time based room treatment, and in the next I seem to be railing about the limitations of it (if not done comprehensively) as well. But there is a middle ground that need not cost more then any average component if the tools are brought in (say 2 hours at $200/hour) for a roadmap that will provide you with precise measures to be taken. And you DON'T need to buy these fancy name brand treatments designed to solve all of your absorption/diffusion needs while actually only addressing a very narrow frequency range! As if Sonex will absorb LF! Well enough, but there are reasonable solutions available! And yes, I am trying to come up with a simpler way that we can help others with their rooms!! But it is a little premature as all of the pieces are not complete...But I will try to keep you posted! And I sure wish we could post attachments!!!! Maybe I should simply cuss, as That seems to get a prompt response! Quote Link to comment Share on other sites More sharing options...
KlipsDude Posted July 18, 2005 Share Posted July 18, 2005 Also, make sure it's not something with one of your equip. going out making the sound change. I had that happens before around 1998 or 1999, and when I got it fixed, the sound was back again, then six months later the thing did it again so I got rid of it. I got that amp used so could be why he gots rid of it cause the repair said it looked like serviced before. Just a thought. Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted July 18, 2005 Share Posted July 18, 2005 Hey rplace I believe it would be a good idea to again simplify your equipment setup temporarly till you get the two channel center correct. You might have already done this but if not a first step would be to test both speakers for proper output. If you have a test disc with some frequency sweeps of say 1/3 octave pink noise say from 20hz to 20khz then run this test first on the left channel/speaker then the right channel/speaker to make sure that the midrange and tweeter drivers are working properly.If the midrange or tweeter driver in one speaker isn't working properly it could really throw your imaging off. Now if all drivers sound like they are working then I would suggest you run both channels/speakers with this test and notice if the image of these test frequencies stay centered. Now you will probably notice some pulling to the left or right of center depending on your room reflections interfering with the direct sound from the speakers but the more frequency bands that stay centered the more solid the center image will be. If any group of bands say like in the squawker or tweeter ranges don't display a center image then reversed polarity of the driver or drivers (which crossover do you have? because it is possible to cross up the polarity of the Squawker/Tweeter Crossover of the AK-2 AND AK-3 crossovers with the Bass Horn Crossover section of the Khorn)would be a likely cause. If you still have problems then like others have sugested if your absorption is overdone in the squawker/tweeter frequency range and/or just in the wrong places it can make the center imaging vauge and recessed especially centered vocals and the life and dynamics of the music will suffer also. mike Quote Link to comment Share on other sites More sharing options...
WMcD Posted July 18, 2005 Share Posted July 18, 2005 Just to humor me. See if the midranges on the K-Horns are both working. I don't know how phase or polarity is checked in your system. However, it has to be checked against a reference. My thought is that if everything is being found to be out of phase, it means the reference is not working. My thought is that the reference signal is in the midrange frequency band, therefore a midrange driver may have a bad connection. Gil Quote Link to comment Share on other sites More sharing options...
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