I managed to fix the marantz. Turns out that the well known cut-out problem was also to blame for the ripple. Thanks to some helpful pointers over at the solid state sub-forum I followed the very noob-friendly guide here: http://www.hifidatabase.com/marantz_pm4000.pdf
No more ripple
No more ripple
Is this a single speaker at the listening position? Those peaks are quite strong!
Do not only look around the speaker, as something close to the microphone can also show up in measurements.
(I'm asking because that first double peak looks like a stereo pair measured just outside the sweet spot, usually a very small microphone movement fixes that.
It could also be a tweeter/mid misalignment)
Do not only look around the speaker, as something close to the microphone can also show up in measurements.
(I'm asking because that first double peak looks like a stereo pair measured just outside the sweet spot, usually a very small microphone movement fixes that.
It could also be a tweeter/mid misalignment)
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It is, I literally live in a house made of concrete and 40% of the side walls are glass.
This is a view from the terras, speakers are on the left and there is a glass wall partitioning the basement stairs form the rest of the living room. Concrete is poured inside the lego-block looking styrofoam.
The 300µs reflection is probably from the leather couch headrest to the mic so I'll have to redo the measurements with the couch out of the way.
This is a view from the terras, speakers are on the left and there is a glass wall partitioning the basement stairs form the rest of the living room. Concrete is poured inside the lego-block looking styrofoam.
The 300µs reflection is probably from the leather couch headrest to the mic so I'll have to redo the measurements with the couch out of the way.
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I took some pictures of the room (hopefully X doesn't spot anything "compromising"
View from the open kitchen
View attachment 539290
The "problem area"
View attachment 539291
Lol...
I see no illicit drugs, booze, dubious magazines, etc
You are squeaky clean.
Obviously, the scene has been scrubbed for any incriminating evidence.
Nice apartment/house. Given that the TV sits on the floor and is still CRT we can see you don't watch much tv but prefer to listen to your speakers or pass the time building giant jigsaw puzzles on that nice table in the middle of the room.
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Nice thread thanks sharing great build including hard work.
Could imagine get right measurements and correction below 500Hz in home environment where you have three drivers to sum correct is not easy. If it can help one big problem i see in living room picture is for right speaker 22W sit in point in space having nearly same distance to two boundary's, the rear wall and height above floor which makes a suchout and if my guessing for distances and baffle plus room size is close will look like picture-1. Left speaker is probably worse having 22W nearly same distance to three boundary's the rear wall and height above floor plus sidewall as seen in picture-2. Plots are from "Baffle Edge Diffraction Simulator" by Jeff Bagsby v1.20 (Link here software) and from own experience those predictions sadly turn up in real world. Room gain below 100Hz is included in plots and regarding nulls or spikes they go away when the three boundary's are as different as possible, but that sadly seldom suit speaker placement in real world rooms. Think one have four options, either correct speaker away from boundary's and live with when placed back in normal position there will be errors in summing, or measure speaker at normal position and correct for room modes either with minimum phase amplitude EQ, or with FIR amplitude EQ ("Paragraphic Gain EQ" tab in Rephase but shifted from standard "minimum-phase" to "linear-phase"), or make the amplitude correction with 50% IRR and 50% FIR or other mix, depending on if room modes looks like minimum-phase or linear-phase or a mix.
Regarding inverted IR/SR one can into REW "Preferences" "Soundcard" tab set "Input Options" to "Invert", but have noticed it is probably when doing correction in Rephase it sometimes ends with phase hover around either +180º or -180º instead of hovering around 0º point as in picture-3. To correct this inside Rephase then just before generating a IR-wav file look in plot if phase is hovering around 0º or not and if not go to "General" tab and play around with "Polarity" setting.
If your SR is near-field measurement think 5mS decay seems right looking a sim of 26W in sealed get a f3 around 40Hz, but if measurement is far-field with room gain it ought to be longer, also it reach 80% and not 100% is that a amplitude or timing issue or because of room such outs. Got myself a pretty good looking SR over time for 2-way FAST system as in picture-4 and can recommend shoot for as low a linear extension as possible close to DC because it turns out low end roll off have a ringing tail up in midrange area when looked at in waterfall plot, so getting that roll off as low as possible to DC cleans up midrange in waterfall and think is clear reflected under listening if low end reach at same is reasonable smooth.
As wesayso suggest can recommend try APL_TDA, think its very good to reveal timing precision for XO points in multi-way speakers. It seems has right filtering out of box to show real world performance, but had by trials seen that REW comes pretty close if you set "Spectrogram" settings as in picture-4. Picture-4 and 5 is same measurement setup, just executed with two different programs, and regarding room modes for my speaker position in room there's a peak at 40Hz and a big such out at 80Hz plus a little dip at 180Hz.
Admire your hard work to get 4 drivers in perfect sync, in that regard i'm a chicken having only two : )
Could imagine get right measurements and correction below 500Hz in home environment where you have three drivers to sum correct is not easy. If it can help one big problem i see in living room picture is for right speaker 22W sit in point in space having nearly same distance to two boundary's, the rear wall and height above floor which makes a suchout and if my guessing for distances and baffle plus room size is close will look like picture-1. Left speaker is probably worse having 22W nearly same distance to three boundary's the rear wall and height above floor plus sidewall as seen in picture-2. Plots are from "Baffle Edge Diffraction Simulator" by Jeff Bagsby v1.20 (Link here software) and from own experience those predictions sadly turn up in real world. Room gain below 100Hz is included in plots and regarding nulls or spikes they go away when the three boundary's are as different as possible, but that sadly seldom suit speaker placement in real world rooms. Think one have four options, either correct speaker away from boundary's and live with when placed back in normal position there will be errors in summing, or measure speaker at normal position and correct for room modes either with minimum phase amplitude EQ, or with FIR amplitude EQ ("Paragraphic Gain EQ" tab in Rephase but shifted from standard "minimum-phase" to "linear-phase"), or make the amplitude correction with 50% IRR and 50% FIR or other mix, depending on if room modes looks like minimum-phase or linear-phase or a mix.
Regarding inverted IR/SR one can into REW "Preferences" "Soundcard" tab set "Input Options" to "Invert", but have noticed it is probably when doing correction in Rephase it sometimes ends with phase hover around either +180º or -180º instead of hovering around 0º point as in picture-3. To correct this inside Rephase then just before generating a IR-wav file look in plot if phase is hovering around 0º or not and if not go to "General" tab and play around with "Polarity" setting.
If your SR is near-field measurement think 5mS decay seems right looking a sim of 26W in sealed get a f3 around 40Hz, but if measurement is far-field with room gain it ought to be longer, also it reach 80% and not 100% is that a amplitude or timing issue or because of room such outs. Got myself a pretty good looking SR over time for 2-way FAST system as in picture-4 and can recommend shoot for as low a linear extension as possible close to DC because it turns out low end roll off have a ringing tail up in midrange area when looked at in waterfall plot, so getting that roll off as low as possible to DC cleans up midrange in waterfall and think is clear reflected under listening if low end reach at same is reasonable smooth.
As wesayso suggest can recommend try APL_TDA, think its very good to reveal timing precision for XO points in multi-way speakers. It seems has right filtering out of box to show real world performance, but had by trials seen that REW comes pretty close if you set "Spectrogram" settings as in picture-4. Picture-4 and 5 is same measurement setup, just executed with two different programs, and regarding room modes for my speaker position in room there's a peak at 40Hz and a big such out at 80Hz plus a little dip at 180Hz.
Admire your hard work to get 4 drivers in perfect sync, in that regard i'm a chicken having only two : )
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Wow, thanks for the thorough analysis BYRTT
Also your spatial reasoning must be pretty good to be able to tell all that (and be spot on) from a few pictures.
I knew about the floor bounce which is one of the reasons I wanted to cross lower with the satori. I hadn't given room positioning much thought because there isn't much wiggle room to place them.
Exact position of the 22W is 62cm from floor, 69cm from back wall and for the left speaker 120 cm from left wall and 155 from left window. I could pull the speakers and the sub out another 10cm and move the left speaker 20cm closer to the wall.
I can also put damping material behind the speakers (I can put it in the bottom half of the CD rack for the right speaker). Other possibilities for damping material include, but are not limited to, putting a big basstrap in the corner next to the tower of power. Maybe up to 3 panels between the back speakers but that will depend on how much they decrease the huge spatial feeling I get with the glass wall (I did choose to put a glass wall there for a reason knowing it'd be horrible for acoustics).
The ceiling has a height of 2.6M more then enough room to make a "ceiling island" with spots above the seating area and or the dinner table.Something like this but then covered with fabric and with damping material inside.
Another user here, I forgot who, put some big 2inch thick cotton rope in all corners of the room except floor/wall corners and seems to be quite happy with that. Cotton rope is very flammable and very expensive so if I find something else smallish and unobtrusive for the top corners I could try that but ready made foam is too big for my taste.
I also downloaded APL_TDA but haven't gotten it running on the laptop yet.
I don't think i'll adjust the output of the speaker to the room at the dinner table. But I have 3 FIR presets in Najda so I can make a "critical listening" preset for couch only listening.
. It is vented and tuned to 20Hz so maybe not that far. If I stuff the vents it has a Qtc of 0.5 and should still do 102dB at 20Hz with 230W, so together with room gain that might be the best option.
After building it I made lots of room measurements and tried many DSP settings to even out the output, in the end I settled for no correction because it always sounded weird on some tracks on the couch and insane at some other locations in the room. I'm hoping having 3 sources capable of ~35Hz now will even things out a bit better.
Also your spatial reasoning must be pretty good to be able to tell all that (and be spot on) from a few pictures.
I knew about the floor bounce which is one of the reasons I wanted to cross lower with the satori. I hadn't given room positioning much thought because there isn't much wiggle room to place them.
Exact position of the 22W is 62cm from floor, 69cm from back wall and for the left speaker 120 cm from left wall and 155 from left window. I could pull the speakers and the sub out another 10cm and move the left speaker 20cm closer to the wall.
I can also put damping material behind the speakers (I can put it in the bottom half of the CD rack for the right speaker). Other possibilities for damping material include, but are not limited to, putting a big basstrap in the corner next to the tower of power. Maybe up to 3 panels between the back speakers but that will depend on how much they decrease the huge spatial feeling I get with the glass wall (I did choose to put a glass wall there for a reason knowing it'd be horrible for acoustics).
The ceiling has a height of 2.6M more then enough room to make a "ceiling island" with spots above the seating area and or the dinner table.Something like this but then covered with fabric and with damping material inside.
Another user here, I forgot who, put some big 2inch thick cotton rope in all corners of the room except floor/wall corners and seems to be quite happy with that. Cotton rope is very flammable and very expensive so if I find something else smallish and unobtrusive for the top corners I could try that but ready made foam is too big for my taste.
I also downloaded APL_TDA but haven't gotten it running on the laptop yet.
I don't think i'll adjust the output of the speaker to the room at the dinner table. But I have 3 FIR presets in Najda so I can make a "critical listening" preset for couch only listening.
I'm not sure I understand 100% of what you are saying here. In any case after I get a grip on the speaker performance I intend to work on the sub integration. I wonder how far I can push the step with a 16Hz capable sub
. It is vented and tuned to 20Hz so maybe not that far. If I stuff the vents it has a Qtc of 0.5 and should still do 102dB at 20Hz with 230W, so together with room gain that might be the best option.After building it I made lots of room measurements and tried many DSP settings to even out the output, in the end I settled for no correction because it always sounded weird on some tracks on the couch and insane at some other locations in the room. I'm hoping having 3 sources capable of ~35Hz now will even things out a bit better.
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I moved the speakers and the sub out some 10cm and remeasured at the listening position with the couch and table out.
I might try to work on the area from 500-2K with DSP, the huge 7-8dB dip at 350 seems a bit much to try and brute force. The plots do look similar enough to take the central position as a base and work with that.
Right STEP
Right wavelet
Left STEP
Left wavelet
Lots of red is good right
I might try to work on the area from 500-2K with DSP, the huge 7-8dB dip at 350 seems a bit much to try and brute force. The plots do look similar enough to take the central position as a base and work with that.
Right STEP
Right wavelet
Left STEP
Left wavelet
Lots of red is good right
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.....
Lots of red is good right
: ) guess so when comparing to reference, below is Rephase ouput 192kHz IR-wav files imported to REW. First is without any correction which is comparable to frq range from DC to light speed and second is in forth tab "Minimum-Phase Filters" setting stop-bands as BW2 5Hz - 22kHz.
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Comparing the couch + table vs the new graphs paints a better picture frequency wise. Without couch everything >1.5K is flat so lets assume the dips and peaks with couch are due to the mic being too close to the reflecting couch. With everything normal the dip at 900 gets smaller and pulling the speakers an extra 10cm from the wall seems to only makes the dip at 300 wider.
So decreasing the 22W output by 4dB and placing the speakers again closer to the back wall should give a pretty good response except for a narrow dip around 300 and a small peak at 650 which can hopefully be fixed with some damping behind the speakers.
.....I'm not sure I understand 100% of what you are saying here. In any case after I get a grip on the speaker performance I intend to work on the sub integration. I wonder how far I can push the step with a 16Hz capable sub
What i mean is if we study first plot below and can trust REW waterfalls it makes sense having as close to DC a smooth low extension because we then clean up ringing tail from 2nd order roll off filter that disturb high up into midrange. We probably not need any amplitude down there to reproduce audio tracks but having it go smooth very low seems give the very clean fast coherent sub to mids we probably seek for, you know fast decay and silence after a kick drum instead of that boomy tail higher frq roll offs show in waterfalls. I always thought when add example a high pass filter BW2 at 50Hz i hear a much cleaner woofer and less distortion, that can be true but as seen in plot it also add a much slower and longer ringing bass, where the close to DC example gets bass handled in first slice of waterfall.
We in same boat at listening position as my own two-way FAST also fall apart out in room as in second picture.
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