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10-01-2017

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martinshorn
Germany
Posts 114
Joined on 04-14-2017

Post #:	221
Post ID:	23429
Reply to:	23428

Nice bias

hi Romy
Nice bias battery gimmick for the el-caps!
But, i see the hardcore analogue teams are having a hard time with room modes and time alignment Smile

I wonder what it takes to admit one day that you can’t neglect DSP anymore, and just having so much easier life.
Cheers Josh

10-01-2017

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Romy the Cat

Boston, MA
Posts 10,132
Joined on 05-28-2004

Post #:	222
Post ID:	23430
Reply to:	23429

DSP is too intrusive and defeats the purpose.

martinshorn wrote:
But, i see the hardcore analogue teams are having a hard time with room modes and time alignment I wonder what it takes to admit one day that you can’t neglect DSP anymore, and just having so much easier life.

Josh, not really. You see it is depending of what constitutes a definition of success? The time alignment I do not even discuss as it is unavoidable axiom in my view. The room modes for sure is a problem but here is where we need to match the topology of playback to the specific of the room. With a proper topology of LF enclosure the room mode is usually not be a factor. To find the proper topology is a bitch of cause.

Now about the DSP, the same answer: depending of what constitutes a definition of success. If one has a definition of success to have a flat frequencies response in a room then for sure DSP is a wonderful tool. However, the experience that we get from a playback is not only about frequencies response, in fact the frequencies response in reality is less aggravating factor. Phase anomalies produce more listening distraction then amplitude anomalies. Anyhow, besides the bad phase anomalies that DSP produces it has a LOT of other quote negative listening contributions that in my view more distractive then room modes.

Let me to give you an association. If the only thing you care in a playback setup is a frequency response then let presume that the only think that you care in grilling steak is to get internal temperature 130F. You can get the steak grilled via burning a kerosene burner, propane, natural gas, coal, charcoal briquettes, commercial lump charcoal, binchotan, coconut shells or make your own let say cherry charcoals by burning own wood. If you objective to burn the steak to a reference temperature then you can accomplish if by any of the fuel. The very same is with DSP – you can fulfill your objective to get a flat response. The fact the your medium rare playback will have too many ashes, have fragrance of additives and smell of chemicals is might be not something that you care.

I do think that if people go to DSP solution, which is perfectly reasonable solution, then the entire playback should a table radio, some kind of contemporary boom-box for $1000, which actually do produce very good sound, in fact much belter then 99% of crap at high end audio shows. If a person go for discrete elements and is trying to shape own sound then from what I see use the DSP is too intrusive and defeats the purpose.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

10-01-2017

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clarkjohnsen
Boston, MA, US
Posts 298
Joined on 06-02-2004

Post #:	223
Post ID:	23431
Reply to:	23430

The grilling analogy

That's excellent!

I once was called to a friend's house to assess the sonic effects of a room DSP he was auditioning. I brought Kwame, my most trusted ears, along. Indeed Jack had a difficult-looking room. So we sat down to listen to some music with the DSP set to how the installer left it. The thing had an In/Out switch and of course we went back and forth several times, and in the In position things did sound flatter, especially in the bass. Then Kwame asked whether the unit was entirely out of the circuit when switched to Out. Jack didn't know, and Kwame suggested removing it physically via cable rearrangement. And you know what? We all preferred it that way!

10-02-2017

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Romy the Cat

Boston, MA
Posts 10,132
Joined on 05-28-2004

Post #:	224
Post ID:	23433
Reply to:	23426

Some listening today.

Spent great time and with happy with result. Not the results are so spectacularly good but the playback is back to be operational that I was missing for a while.

Starting with films. The damn OPPO has not enough output for my Milq. I decided to get rid any SS amps for now and pilot speakers, unless until I will be able to make my SS amps to have higher input impedance. When OPPO drive Milq I do have OK sound but I have no volume, I need ether drop a feedback in OPPO output stage or to put a nice proxy preamp with gain between OPPO and my unity gain Placette. I have Yamaha C-4 that I employed to the duty but it gave me so much compression that it is hard to listen. I need probably go for all of those DIY people who tweak OPOs output and too see if I can swing it to 2-3V. Still, I sat down to listen a Lincoln Center’s Sweeney Todd recording from 2014, with great Bryn Terfel and was not able to stop watching it. Regardless the sound, I miss these experiences: to veg out in the listening chairs and let the world to pass by in front your ears/eyes…

Music. Good and bad. I set the left channel, the one that have a solid corner in there, and did some measuring. I would need a second order low pass filter in there at 20-25Hz. Yep, it has 20Hz and then runs all the way to 70sHz with extra 6-8dB, a LOT of bass. Putting it on the transaction 12dB slope at 20-25Hz should kill the problem. Overall listening of both channels is surprisingly pleasant from amplitude perspective. The overall sound is a bit “heavy” but tolerable. The 6-8dB peaks are very narrow and being incorporated in the overall first order poll they are not so prominent. I would say I need to kill overall 2dB from anything under 100Hz and the sense of “heavy” should be gone and I will be seeing how individual amplitude irregularities affect listening experience. Tonally I hear some very pleasant overtone from midbass, pleasant. However, the so much desired long decay that I am so much straggling to get has not so pleasant tone. The legendary North German Radio Symphony recordings in Lubeck do not sound as orgasmaticly wonderful they should, the “royal” sonorities are not there. At this point it is hard to propose the reasons, I need to make the sound properly balanced overall. I have ordered a few Jantzen 14 AWG C-Coil Toroidal Inductors, will do the precise crossovers to dial into the room. The last aspect that I need to mention is imaging. Not that it is important itself but imaging is a very easy and very easy to observe side effect of phases processing and time-alignment, which have a huge impact into musical engagement and human interaction with playback. My first sentiment was that it was a disaster. From a VERY stunning imaging I had when the Vitavoxes midbass were sitting time-aligned I went to very ugly imaging when neither midbass nor lower bass very much no time- aligned. I for sure have my 20Hz now but I need to think about my priorities again. I did not experiment with imaging in new setting but it was way worse then I expecting. Ether something is accidently running out of phase in there (with 14 channels it is easy to lose it) or my parley into “phase joker” with my midbass is a stupid idea that serve only my amplitude objective.

I will continue to play with what I got myself into but despite all negativism I am very pleased with the result. You see, this week did show to me that I can go away with Milq driving my bass line-array with juts 6 driver. That was something that I did not know before and I find it very encouraging. I just need to find a way to make it to work.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

10-08-2017

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Romy the Cat

Boston, MA
Posts 10,132
Joined on 05-28-2004

Post #:	225
Post ID:	23458
Reply to:	23433

Back to the drawing table.

My experiment with midbass channel last week was wonderful in a wild position. It proved that I have enough gain to drive my current bass tower from Milq. Also, it proved that using a small midbass in wild position and playing with crossovers I can make a nice a very nice more or less even frequency response in the room. After doing all of it, as I told before, I was not pleased with result subjectively. The imaging was suffering horribly and along with the engagement with music is gone. I need to note that engagement has nothing to do with imaging. The imaging is just a side effect of time-alignment and as system become time-misaligned at LF the engagement with music is gone, the imaging is just easy to spot adverse effect. You do not need to be too much trained to recognize the lock of engagement. It is very obvious as a time-aligned system has “magic” as very tangible property. So, I am completely discarding my experiences from last week and will be targeting to try find a configuration when midbass and LF channels to be in time aligned position.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

10-08-2017

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anthony
Posts 338
Joined on 08-18-2014

Post #:	226
Post ID:	23459
Reply to:	23458

Bring them forward

By the looks of the earlier photo, you will be bringing the LF and midbass channels quite a ways forward, perhaps 3 or 4 feet, but it is difficult to judge distance from the image. Will you have enough room for the midbass boxes to snuggle in beside the UB horns, or do you have something else in mind?

10-08-2017

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Romy the Cat

Boston, MA
Posts 10,132
Joined on 05-28-2004

Post #:	227
Post ID:	23460
Reply to:	23459

Promising....

Spent today a whole day moving the boxes, do some measurements, fighting with REW interface, thinking, some listening… Found some bugs in the system that I think screwed my initial feeling. The bugs were mostly by Thomas the Son touched what he should not be touching…

Anyhow, upon further experiment I did fine a nice configuration that it feels like sound very nice. On the specs it is kind of ridicules but if to look deeper than it is a very proper revers response of my room and the sound is surprisingly well balanced.

The left channel, the one that has a well formed corner, has 4 drivers line array with pimpled driver. Yep. Juts 4 driver, extra two drivers is too much. It has second order low pass filter at 20Hz, so the entire bass is sitting on the transitional slope. I get 0db at 23Hz and then 12dB dive. The channel pushed +6dB at 50Hz, which is perfectly fine. The line array is time-aligned. The Midbass is sitting atop of the Line-array, it is one sealed Vitavox with 50-125Hz band pass, first order. The Midbass is inverted and not perfectly time-aligned but phase-aligned. Well, it is time-aligned to the top driver of the array, whatever it worth… The moving of the Vitavox with an inch hugely affect everything and primary and surprisingly the sub 20Hz region…

The right channels, the one that has no corner and has a lot of open space to the rest of the house has 6 line-arrayed pimpled drivers. It is 30Hz, first order, time-aligned. The Midbass is the same 50-125Hz band pass, first order but siting on the floor, elevated for 30inch, time-aligned.

So, it is kind of strange configuration but sonically it is very easy for ears, and compensates the acoustic asymmetry of my room very nicely. I do not know if it is the last version but it is the very best that I have in this room so far. The important factor to me that I do not have now the tonal problem with bass, it goes very low with no overblowing and tonally it is not problematic anymore. Also, it is lash and gently decaying: the idea to keep first order on the channel that has no walls was a brilliant in my view.

I also found a way to deal with my video sound: I run digital out from OPPO to Lavry Gold that has 1.5V output voltage, enough to drive the thing loud enough.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

10-09-2017

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martinshorn
Germany
Posts 114
Joined on 04-14-2017

Post #:	228
Post ID:	23462
Reply to:	23460

Aligned how?

i see the words time alignment quiet often in this forum Smile

Which is a good thing. But can you show a graph / measure that says what it means in a result?Or do you just mean the woofer is standing next to the mains?
Cheers Josh

10-09-2017

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Romy the Cat

Boston, MA
Posts 10,132
Joined on 05-28-2004

Post #:	229
Post ID:	23465
Reply to:	23462

Elementary, Watson. :-)

martinshorn wrote:
i see the words time alignment quiet often in this forum Which is a good thing. But can you show a graph / measure that says what it means in a result?Or do you just mean the woofer is standing next to the mains?
Cheers Josh

Josh,

I have been written about it for years and there are plenty of it within this site. The time-alignment is one of the basis of the Macondo Axioms:

http://www.goodsoundclub.com/Forums/ShowPost.aspx?postID=4832

I am not sure I can show it to you in graph/measure what it means. At higher frequencies time-alignment is co-alignment of pulse responds for individual channels, in my case the HF, MF and Injection. This s very simple to measure and to demonstrate via pulse measurement. At sub MF channels it is much more complicated. The rules of sum recommend to use lower IR window to very short time, filtering the reflection and to treat the signal almost as it is HF signal. For sure it is good and allow to set the diaphragms of deferent channels equidistant to the listening position but I do not find that it is a right direction to go. One of the notion that I advocate is not to fight with listening room but to embrace the sound of the room into the design of acoustic system. Therefore I measure the time-alignment of sub MF with no cancelation of any room reflections or with combination of no cancelation with very moderate cancelation. Knowing the frequency I am dealing with I know the wave length. So, I can place a chance with visual co-aliment of the diaphragms and this will assure that within a relatively long wave length the channels are in the same period. Then all that I care it to so-align the phase in the period, or to make channels to hit the peak of sinusoid at the same time. At LF is it mess but the most important is that reflections to great degree screw the whole picture. So, What I frequently do is to drive across both channels a single frequency in the mid of the crossover divide and moving one of the channels (which was not aligned with upper frequencies) to get the maximum gain in amplitude of that single frequency. The presumption is that in case both channel hit peak of sinusoid the gain will be maximum. Pay attention that in my case the room is very much part of the picture….

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

10-16-2017

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Romy the Cat

Boston, MA
Posts 10,132
Joined on 05-28-2004

Post #:	230
Post ID:	24482
Reply to:	23465

Nice but need more work

Yesterday I have a great listening time. I sent Amy with twins to her parents. I put Thomas to sleep in his room and as he woke up I set him to watch his Caillou for hours and I went to my listening room to have nice quality time with my playback. I had so much pleasure yesterday that it is hard to express. I did some fiddling with playback I have 2-3 hours pure marinating in my listening chair to listen the music I like. I ended up falling asleep in my chair, blasting Bruckner at full volume. This is in fact a good sign, it means I am getting more comfortable with the sound in my listening room. It was as much pleasure as I use to have during my time what I was single. The exception is that I was able to smoke my beloved Perdomo 20th Anniversary cigars but no smoking in hour nowadays…

Anyhow, I setup back my computer to play mucks. It took for me 1.5 years to do but the DAW is back. I found a good configuration for movie. I use OPPOs analog output to drive SS amp with Dunvavy III what my family want to watch sports or cartoons. And I use OPPO digital out to drive Lavry 924 and then to maim Milq-Macondo playback when I want to watch opera or concerts or whatever video program that need good sound. This is very good configuration as the SS amps in this setting does not drive interest in any way with my main playback and I can run SS playback in complete isolation.

The overall sound: I’m getting there. The idea use Milq to drive my woofer tower is completed with great success. The woofer towers are at 20Hz second order on left and 40Hz on right with complementary midbass above. It is very nice low octave range. I have some strange addiction to my pimpled Scanspeaks drivers. I adopted them in 1999-2000 when John Dunvaly converted his SC-IV speakers to SC-IVA, pretty much replacing woofers he used before with drivers 10” pimpled Scanspeaks. The SC-IVA were very well accepted for very positive change in bass. I hear the SC-IVA ion some kind of audio shop in Belgume, it was driver by some kind of little Czechoslovakia tube amplifier and it had a spectacular bass. I said: Wow! And fallen in love to it. As I got home I got a woofer tower from John with 4 drivers and I love each second or it. The drivers use the Scan-Speak SD-1 motor and it is unique. It was invented by Lars Goller in 1992 and the idea was to have VC much longer to assure that at any exertion the VC will be in linear part of the magnetic saturation. The guy who runs North Creek Music does explains the notion very properly:

http://www.northcreekmusic.com/Retired/Borealis_and_Rhythm/borealis_and_rhythm.html

I am not sure if the excessive VC is better than overhand VC as AuraSound use to do but nowadays no one do the proper overhand as it too expensive. For sure the direction the Scan-Speak went waste a lot of efficiency of the drivers and this sucks for sure. If the driver were not 88.5dB but 98dB it would be so much more fun!!!

Anyhow, I am not sure what makes my 10” pimpled Scanspeaks to sound so appealing to me. The best think about them is accommodations. Most of the drivers sound predictable. You load them in the way how you load them and the drivers sound in accordance with their damping characteristic. For the no-feedback SET it is a typical transient vs harmonics compromise. There is nothing to invent in there. Not with my pimpled Scanspeaks. The pimpled Scanspeaks for all intended purposes sound like heavily over-damped drivers. Still, if the signal calls them to throw some so transient balls then the driver do it for some reasons. I have no idea why. I absolutely love how the over-damped pimpled Scanspeaks sound and now as I ride above them the super dry midbass Vitavox it is even more exiting.

With the lower octave questions is fading away I think the only problem is left with my playback is imaging. The midbass channels are still not properly times, the different crossovers have own phase disturbances and the overall imagine is not as good as I use to. The 6-7 feet integration is not work well now as at some phase problematic recording I have an ugly “hole” in the middle with right and left channel do not talk to each other. It take a very accurate time alignment or everything to make the trick to work. I can’t also to move the R and L channels closer to each other as I have 125” screen is dropping between. So, I am planning to virtualize the middle aims by moving the mibdbasas between the channels but looking lower bass outside. It would require to move the amps somewhere but I am willing to do it. I think I will be in a good shape with my new listing room eventually.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

10-21-2017

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Romy the Cat

Boston, MA
Posts 10,132
Joined on 05-28-2004

Post #:	231
Post ID:	24483
Reply to:	24482

Getting there...

Spend a good few hour moving the boxes, connecting the cables and do other sort of things. Was looking for elegance and more symmetry. The objective was to put midbass channel between the main horn islands and set the horns, the midbass and LF in very firm time-alignment. I am not wild about locating midbass inside and I always advocate to put them outside of the imaging aria but my case is special. I do feel that my speakers are good 2 feet further from each other then they should be and they force me to site further then I would like to as I am getting a bit deeper imaging indentation the middle then I accustomed to. I can’t move the speakers closer and I have retractable 140” screen between the horns. So, the idea was to put the midbass inside in order to virtualize moving the main speaker slightly closer to each other.

Generally it worked very well but it was ugly as there was no good location for the amps, at least sexy location. So, addressed the problem slightly controversial: buy placing the amps atop of the midbass enclosures. I did not detected that the midbass is shaking a lot. In addition the amps are siting atop of very nice custom-made Silent Running Audio platform. There is also 1” rubber sheet between the bottom of SRA platform and the midbass box. I was listening with Amy’s statoscopes the vibration of the Milq chassis with 0db digital at 80Hz and I was not able to hear anything at the chassis bone-transmitted from midbass. It was so fucking laud over air that if I had anything in statoscopes then I properly was not able to register it.

The setup generally feels very nice. The left 2 drivers of LF are not connected but I desisted to keep them for reasons of prettiness. I need to spend some time to fine tune the crossovers and to listen more but architecturally I think I am all done. Another discovery I made: I am getting old to work on this for hours. I am 49. Not in so great physical shape and it is getting had to jump 344905 times from listening chair and to lift 100 pounds boxes…

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

10-21-2017

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anthony
Posts 338
Joined on 08-18-2014

Post #:	232
Post ID:	24484
Reply to:	24483

It all looks very nice...

...it really does, I like it a lot. Personally, I would prefer to have the equipment rack somewhere else in the room but that is just me.

Romy the Cat wrote:
I can’t move the speakers closer and I have retractable 140” screen between the horns. So, the idea was to put the midbass inside in order to virtualize moving the main speaker slightly closer to each other.

I am sure there is no real need to point out that you could use a smaller projector screen if you really wanted to move the speakers closer together. That, or move the screen further away so that it is "framed" by Macondo when you are looking at it from your listening chair. You may find that you can still see all of the 140" screen if it is closer to the wall, but of course the equipment rack would be in the way.

10-21-2017

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Romy the Cat

Boston, MA
Posts 10,132
Joined on 05-28-2004

Post #:	233
Post ID:	24485
Reply to:	24484

It is still all for grabs.

anthony wrote:
Personally, I would prefer to have the equipment rack somewhere else in the room but that is just me.

The subject of equipment rack to be in or out is well debated by be in past. Unquestionably from sonic perspective it should be out but. There are so many buts in there. You need to run a long interconnect cables from you preamps to power amps. I have 4M vintage Dominus that is not long enough I hardly trust any other cable. Then how to run it? In my former home I drilled a whole on the floor and ran it over in basement. I am not sure if I want to do it now as the ingredients in my cost-benefits analyses are different nowadays. You see, the listening room in our house is not truly a dedicated listening room but rather second family room. Behind the listening couch there is a huge 12 people parabolic sofa and huge 5’x5’ ottoman, which acts sometimes as snack table. So, we slide the listed in chair on side, put the ottoman there and watch movies with wify, whole family or with some odd friends. There are some people even who come to us to watch sports (American football and alike). So, the idea was to have one single location what all audio equipment would be encapsulated. If you see on the left of the LF channel there are two very might portable fences. So, what the kind in the room I run the portable fences between the midbass horns that effectively shield all equipment from the kids. They still manage to inflict damage. Thomas for instance damped dry fish food into right upper bass horn, it was a LOT efforts to vacuum it out. I personally do like the equipment rack between the speakers in THIS room. This room has no better location for equipment rack. I loved that in my former listening room there was a dedicated equipment bay what all equipment was hiding but I do not have it here. When we were hinting for new house and I saw this rooms I got instant vision how my playback will sit in this room and I loved the idea a lot. I still feel that for the size of the installation and for the way how I would like the playback to interact with my non-audio life I get as very comfortable for me compromise. I also like that the playback is not visible what you enter the room. I do not know why but I do not like the installations with curb appeal…

Anthony wrote:
I am sure there is no real need to point out that you could use a smaller projector screen if you really wanted to move the speakers closer together. That, or move the screen further away so that it is "framed" by Macondo when you are looking at it from your listening chair. You may find that you can still see all of the 140" screen if it is closer to the wall, but of course the equipment rack would be in the way.

Yep, I well investigated it. I do not want to use smaller screen. I would love to use twice bigger in fact and I have my fantasy about 200” screen. I can move the screen her and there and save 1 feet but it is kind of pain in ass to make the slanted silent and to find the right location for the whole. Also, of I move the scree closer to the equipment rack then the heat from the amps will be impacting the screen. As now the screen drops right in front of amps, barley touching the injection channels, I might play with it but I doubt that I can get full 2 feet that I think I need.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

10-22-2017

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Romy the Cat

Boston, MA
Posts 10,132
Joined on 05-28-2004

Post #:	234
Post ID:	24486
Reply to:	24485

Great Morning!!!

God, I having fun like at “old time”! Woke up at 4am today, was not able to sleep. Turned the playback, cleaned the room and set the DAW to stream the Bayreuth festival 2017. The ABC is broadcasting tonight the August 3 live recording of Götterdämmerung by Bayreuth and Marek Janowski. Thankfully the new listening room is acoustically isolated wing of the house, so I can blast music as loud and I want. At 7 AM Thomas flocked to my room and then Amy the Wify came and sit at my laps. Got, this is such a great Sunday morning…. Siegfried is dead, I am not yet...

NewListedningRoom_Gotterdammerung .jpg

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

10-22-2017

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Paul S
San Diego, California, USA
Posts 2,644
Joined on 10-12-2006

Post #:	235
Post ID:	24487
Reply to:	24486

Wagner AND Family, at 7 am?!?

You are living the Dream, all right! I think the only time I ever pulled this off was on a family ski trip, blasting "Ride of the Valkyries" on our way to the lifts. But that was a captive audience, and your family came to you! You must be doing something right!

Best regards,
Paul S

10-23-2017

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Romy the Cat

Boston, MA
Posts 10,132
Joined on 05-28-2004

Post #:	236
Post ID:	24488
Reply to:	24483

Some thinking required…

Yesterday I finalized everything, made the crossovers permanent, arranged the cables, check the phases and levels per each channel and officially declared to my wide that the listening room setting up is over. Then as the kids went to bed I decided to spin some music in a comfort of my new re-acquired listening room. I put the scherzo from Mahler Second, tuned the light off, stretched in my chair and pushed play. Instead the customary timpani strike opening the Macondo barked to me with some horsey fart. That was more than unpleasant.

I took my own “test tracks” the recordings that I know for years very well and that I use the debug playbacks. Played it and it was very obvious that the playback was very seriously sick. The sound has very undecided lover end and overall super brittle it was almost like waking barefoot over crash glass. The setting the tweeters lower did not help, so it was obvious that something in my LF was out of phase. It is not very much publicized fact in audio that there is a lot of conception between upper HF and lower LF. I wrote about it a lot in past at my site. So, in this case when the whole upper end was brittle like very rusty knife and lower bass was as ugly as it usually come from open baffle I instantly recognized that one of my LF section is out of phase.
There was however two dilemmas. I just checked all my individual channels and made sure that they are in proper phase. Also just a few days back, even last morning I had great sound with no signs of upper range harshness of bass problems. The environmental problem are out of picture, so what is going on?

I do not have a definitive answer yet even though I was thinking about it whole evening and whole morning today. The most likely is that my playback proper configuration is what LF channels need to be set that right LF side runs in opposite polarity then left LF. Most likely it is what I had before my last setting up. You see, I can’t check the polarity of my left LF and it runs 20Hz filtration and I have no gain to excite my phase miter. I did not bring scope to test it but rather I set with RTA each side LF in max gains to Midbass and Upperbass in max gain to Upprabss. Since the Midbass and Upperbass are in phase with R and L side I was under presumption that LF will be in phase if they in max gain to own Midbass. So apparently, and probably because they have deferent filtration my R and L LF channels runs max gain to midbass in opposite phases to each other. This is the only explanation I have.
If it is so then it will be VERY strange configuration with R-LF and L-LR to be in opposite phase. Sure, they are in very different acoustic environments and runs different crossovers (20Hz and 45Hz second order), they run different impedance change. So there are a lot of explanation why to be in opposite phase would be reasonable. Still it would be strange and unusual.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

10-24-2017

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Romy the Cat

Boston, MA
Posts 10,132
Joined on 05-28-2004

Post #:	237
Post ID:	24489
Reply to:	24488

I never done anything like this…

It is new thing. Yep, I was right. As turned my right LF channel out of phase with my left channel I got my bass back and the super hasty brittle sound was gone. The right LF channel should be running out of phase with the rest of system as it has second order filter. The left LF channel runs out of phase and it does perfectly fine, maximizing the connected gain with other channels at crossover points. The right LF channel dose the same if it runs in phase with the rest of the channels. So it is very bazar situation that lower octave R and L channels runs in opposite phase, measured fine and produce nice sound but running in phase (as they use to be) they do not do very well neither by measurements or by ears.

This open a whole new way of thinking for me. I need to redesign LF second order crossovers (they are different) that would assure not only proper performance for R and L channels but that would assure R and L channels to work best being in phase in THIS room. This is very interesting and I never done anything like this…

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

10-25-2017

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Romy the Cat

Boston, MA
Posts 10,132
Joined on 05-28-2004

Post #:	238
Post ID:	24490
Reply to:	24489

Still have no idea why it works as it does.

I keep thinking about the strangeness of my phase inversion. I still do not think that it should be this way. My leading explanation is because I did not implement the crossover precise. If the crossover called for let way 63mH coil and 795uF cap then I put 70mH and 600uF. That gave OK response but it also make the crossover to act as two not align first order filters that run all possible phase problems. This is just a proposal and I am not sure that I am right. Whatever it worth I will get the cap and coils of exact value and will see if it make any difference.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

10-25-2017

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Paul S
San Diego, California, USA
Posts 2,644
Joined on 10-12-2006

Post #:	239
Post ID:	24491
Reply to:	24490

Phase and Room Modes

Well, this is the difficult time, embedding a changing, complex system into a new, large room. I am not clear if the sound has changed over time (since you were more positive about the sound, earlier) or if you have just become more aware of aspects you don't like over time, with more listening. Of course, phase, location in the room, and frequency all conspire to add to and detract from "different frequencies" bouncing around in there, and these effects will also (typically) vary with listening position. I have no idea how you keep track of all of it, but the first thing I though of when you described the current problems was, it reminded me of my own electricity problems! I think it was Lucas Fikus who said he only paid passing attention to x-over "models", since X/Os tend to vary from models in use, also, in the end, it is only what we hear that matters.

Best regards,
Paul S

10-26-2017

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Romy the Cat

Boston, MA
Posts 10,132
Joined on 05-28-2004

Post #:	240
Post ID:	24492
Reply to:	24490

What a remarkable idiot!!!!

I need to tell you that for a few days I been thinking about what is going on with my channels. The measurements and listening clearly show that I need to invert R and L lowest against each other but my guts keep telling me that it is pure BS. The phase measurement gave me some wild picture that should not be nearly as bad and am kind of stumbled. Well, was stumbled as just an hour ago, after a few hours of sitting in my listening chair in in my mind debugging my playback I did found the problem.

The problem was that I was an idiot. No more, no less. A week ago I spent an hour to assemble my crossovers for LF. I use electrolytic caps with 9V bias, so it is few parts to solder + some speakers’ connections. Is I have done it I hung the caps assemblies on the binding post of my LF channels, forming a second order LC filter. On my left channel I attached the caps not on the binding post of the speaker but to the binding post of the Milq LF, forming instead of LC filter a stupid CL filter. If you feel that it is not a definition of idiocy then I have no idea what would it be!!!!

Anyhow, as I put the cap assembly the right location… after the coil then my LF begin to sum the signal being in phase. Whew!!! That is so match makes senses!!!

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

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