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Multi-Channel, Multi-Amplifier Audio System Using Software Crossover and Multichannel-DAC

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dualazmak

dualazmak

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Nice detective work locating the AC noise riding the musical waveform.

Fortunately, I have no AC noise at all in my digital and analog signals!
 

Doodski

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For the "measured" Fq response before and after these capacitors, please refer to my post here.
- Overhaul maintenance of super-tweeter FOSTEX T925A and further signal fine tuning thereafter: #485
Very good service. I am impressed they still offer it at all. So many companies offer no service and so it is nice to see it when it happens.
As for the 22 Ohm "tuning" resistors "in parallel" with STs (just giving a slight extra work to the amp), you would please refer to;
- In depth insights on SP attenuators and their elimination in multichannel system: #248, #251, #99(remote thread), #100(remote thread), #101(remote thread)
Very sneaky developments how you measured the system padding and substituted with a fixed value. :D
 
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dualazmak

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Very sneaky developments how you measured the system padding and substituted with a fixed value. :D

English is not my mother language, and I am not familiar with slang-ish use of "sneaky"!
May I understand it, in this case, rather positively?;)
 
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I edited/corrected in my above post #660 as:

>I use Yamaha A-S301 to drive super-tweeters (STs) having 30 10 uF "protection" capacitor and 10 3 uF high-pass (low-cut) filter before the signal going into STs.
 

Doodski

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I edited/corrected in my above post #660 as:

>I use Yamaha A-S301 to drive super-tweeters (STs) having 30 10 uF "protection" capacitor and 10 3 uF high-pass (low-cut) filter before the signal going into STs.
Yes, I saw some incongruency in the diagrams too. You got the bad ones. Overall the diagrams are perfect and very visually stimulating. I imagine for a person wanting to delve into the realm of DSP with active crossover and safety precautions that these threads of yours are the places to do it.
 
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Thank you. I am not familiar with "incongruency", but I usually use "inconsistency". ;)
 
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Excellent Recording Quality Music Albums/Tracks for Subjective (and Possibly Objective) Test/Check/Tuning of Multichannel Multi-Driver Multi-Amplifier Time-Aligned Active Stereo Audio System and Room Acoustics; at least a Portion and/or One Track being Analyzed by Color Spectrum of Adobe Audition in Common Parameters: [Part-18] An Interlude or Provisional Finale of the Post Series

Caution and Reminder:
Even though I refer to YouTube video/audio clip(s) in this post, I cannot guarantee its sound quality since I know little about YouTube's audio codec/compression, and furthermore I know nothing about your internet access environments.

(You would please take a look on [Part-00] Introduction here in my post.)


Hello friends,

In this "post series", so far I have shared as follows;

[Part-00] Introduction: #587
[Part-01] Full Orchestral Music: #588
[Part-02] Solo Piano Music: #590
[Part-03] Typical(?) Smooth Jazz Music with Guitar: #591
[Part-04] Bimmel Bolle Antique Orgel; Extremely High-Energy High-Frequency Sharp Transient sound: #592
[Part-05] Color Spectrum of Tracks in CBS/Sony's "Super Audio Check CD": #593
[Part-06] Female Vocal in Jazz and Popular Music, and One Male Vocal Track for Comparison: #596
[Part-07] Female Vocal and Counter Tenor in Early Classical Music: #639
[Part-08] (Smooth?) Jazz Trio: #640
[Part-09] Organ Music: #641
[Part-10] Lute Music: #642
[Part-11] Violin Music: #643
[Part-12] Cello Music: #644
[Part-13] Harpsichord (Cembalo, Clavecin) Music: #645
[Part-14] Piano Concertos: #650
[Part-15] Again, CBS/Sony's "Super Audio Check CD": Analyzed by Adobe Audition 3.0.1 and MusicScope 2.1.0: #651
[Part-16] A Cappella Chorus and A Cappella Vocal Ensemble: #652
[Part-17] Excellent Quality Music Tracks, But Containing Unacceptably High Gain Low-Frequency Air Conditioning Noises; What Counter Measures Can We Have? #658
and this post;
[Part-18] An Interlude or Provisional Finale of the Post Series: #669

Even though I really would like to share "music samplers" of many other genres, segments, eras, instruments, and voices, I am afraid of it would become a kind of "endless" series of posts. Now I decided, therefore, to tentatively/provisionally conclude this "post series" by this present post [Part-18] as "An Interlude or Provisional Finale".

If you would like to suggest another new post in this series with your specific genre/instrument of interests, please let me know without hesitation. Any of your possible recommended "excellent music tracks" would be highly appreciated; if you do not have Adobe Audition, then I will be more than happy to analyze the spectrum of such track.

I believe this "post series" is the very first attempt within ASR Forum sharing "excellent audio sampler music tracks" in systematic manner having the "spectrum" of the intact track being analyzed.

As I wrote in [Part-00] Introduction, I know very well that the Color Spectrum of Adobe Audition (I use Ver. 3.0.1) is not "the almighty" at all. Nevertheless, I assume the Spectrum of specific "intact" audio sampler music track would be more worthwhile than having no such objective representation of the track.

You would please note that I have been using these "audio sampler tracks" throughout my multichannel multi-amplifier active audio project shared on this thread started in April 2020; you may find here (on this thread) and here (remote independent thread post) the bird-eye overview Hyperlink Index of this project.

At each of the steps during the progress of my project (long mountain-climbing exploration, indeed), I always took intensive efforts not only in objective measurements/tuning but also in subjective confirmation and tuning using the "audio sampler tracks". I really like the suggestion given by @Purité Audio (keith) in here; "You must hear equipment in your own room in your own system, compare unsighted (close your eyes) if there isn’t an immediately apparent difference/improvement. To go further, if there isn’t a significant improvement then don’t change anything, the largest gains are speakers and room."

Consequently, my latest Fq response profile and the precision time alignment have been established through "objective measurement and tuning" plus "subjective listening fine tuning using the audio sampler playlist". This latest "all-purpose/standard" configuration is so optimized that fit for almost all of the "audio sampler tracks" shared in this "post series".
WS00004938.JPG


As I repeatedly shared, flexible and safe on-the-fly further relative gain control can be done based on the current "best tuned" parameters; the fine gain tuning depending on the nature/characteristics of music, however, is usually within plus/minus 3 dB window from the present all-purpose setting.
WS00005568.JPG


You would please find the details of the latest system setup as well as the listening room environment in my post #540. In this post, I share only the essential two diagrams and one photo as follows for your easy understandings.

Total system diagram;
WS00005576.JPG


Faces of all the audio equipment/gears;
WS00004840.JPG


As for the unique physical positioning (location) of super-tweeter (ST) Fostex T925As, please refer to my posts here and here.

Looking at the SP setting from my listening position;
WS00004839.JPG



To tentatively close this "series of posts", let me share a single YouTube video clip. Please note that I know nothing about this little girl (age 11 in 2014) other than the video clip. The great music by Bach and the stunning performance by a girl always take me to another world having tears in my eyes. What a miracle/magical beauty and profound power of music; YUKA plays Bach Sinfonia No.11 in G Minor BWV 797.

WS00004838.JPG
 
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dualazmak

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Updated, the latest, Audio Sampler Playlist as of October 20, 2022

Edit:
You would please also refer to:
- Five "real air-recorded transient-sound tracks" of Sony Super Audio Check CD played and analyzed by MusicScope 2.1.0: #760

Hello friends,

By reflecting all the contents described in my recent post series here and thereafter (18 posts), I updated my "Audio Sampler Playlist" which now consists of these 60 tracks;
WS00004864_r1.jpg


The order (track number) of the playlist is assigned in conformity with the "post series";
[Part-00] Introduction: #587
[Part-01] Full Orchestral Music: #588
[Part-02] Solo Piano Music: #590
[Part-03] Typical(?) Smooth Jazz Music with Guitar: #591
[Part-04] Bimmel Bolle Antique Orgel; Extremely High-Energy High-Frequency Sharp Transient sound: #592
[Part-05] Color Spectrum of Tracks in CBS/Sony's "Super Audio Check CD": #593
[Part-06] Female Vocal in Jazz and Popular Music, and One Male Vocal Track for Comparison: #596
[Part-07] Female Vocal and Counter Tenor in Early Classical Music: #639
[Part-08] (Smooth?) Jazz Trio: #640
[Part-09] Organ Music: #641
[Part-10] Lute Music: #642
[Part-11] Violin Music: #643
[Part-12] Cello Music: #644
[Part-13] Harpsichord (Cembalo, Clavecin) Music: #645
[Part-14] Piano Concertos: #650
[Part-15] Again, CBS/Sony's "Super Audio Check CD": Analyzed by Adobe Audition 3.0.1 and MusicScope 2.1.0: #651
[Part-16] A Cappella Chorus and A Cappella Vocal Ensemble: #652
[Part-17] Excellent Quality Music Tracks, But Containing Unacceptably High Gain Low-Frequency Air Conditioning Noises; What Counter Measures Can We Have? #658
[Part-18] An Interlude or Provisional Finale of the Post Series:
#669

To create this updated "Audio Sampler Playlist", I copy-pasted all the intact 60 tracks into a new library folder in my SSD with both "Artist" and "Album" as "Audio Sampler 20221020"; using JRiver MC's tag editing utility I intentionally changed the "Artist", "Album Artist" and "Album" as "Audio Sampler 20221020", and re-assigned the track no. of 01 - 60 as shown above which also in conformity with the "post series". The SSD file structure is shown here;
WS00004865_r1.jpg


The ZIP file (5.8 GB) containing all the 60 intact tracks has been also prepared for possible communication with my audio-enthu friends. In case if you would be seriously interested in these intact (non-compressed) audio sampler tracks, please simply PM me writing your wish.

As for policy and organization of my digital music library, you would please refer to;
- How to organize digital music library; sharing my policy and operation: #004(remote thread),
#346
 
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dualazmak

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Semiannual complete cleaning of all the metal-to-metal connectors

Hello friends,

The day before yesterday, October 30 Sunday in Japan, the autumn clear blue sky with temperature 19 degree C (66 F) and the comfortable dry air (humidity 39 %), was just perfect for my semiannual complete cleaning of all the connectors in my audio setup.

I usually use only these items for cleaning of all the metal-to-metal connectors in my audio setup; 100 % isopropyl alcohol, cotton swabs with 2.4 mm diameter compressed paper rod, micro-porous ceramic RCA cleaning rods, dust blower (compressed air duster).
WS00004902.JPG


The 2.4 mm diameter compressed paper rod of the cotton swab with a little amount of IPA (isopropyl alcohol) is just perfect fit for cleaning of XLR female connectors. Of course, I dry-up all the connectors with the air duster after the cleaning with IPA.

(You would please refer to my post here and here for the details of the latest system setup.)

I carefully clean-up all the metal-to-metal connectors (male and female), including AC power inlets, XLR and RCA connectors, SP cable Y-lugs and AMP/SP binding posts, SP cabling board screw connections, USB I/O connectors, etc. It takes about four (4) hours to complete the intensive semiannual cleaning.
WS003808.JPG


WS003804.JPG


I usually do it on sunny dry day in early May and late October.

I believe you can easily guess/understand the positive/favorable effects of such a complete/intensive cleaning of the connectors actually and/or psychologically audible.
 
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Doodski

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Semiannual complete cleaning of all the metal-to-metal connectors

Hello friends,

The day before yesterday, October 30 Sunday in Japan, the autumn clear blue sky with temperature 19 degree C (66 F) and the comfortable dry air (humidity 39 %), was just perfect for my biannual complete cleaning of all the connectors in my audio setup.

I usually use only these items for cleaning of all the metal-to-metal connectors in my audio setup; 100 % isopropyl alcohol, cotton swabs with 2.4 mm diameter compressed paper rod, micro-porous ceramic RCA cleaning rods, dust blower (compressed air duster).
View attachment 240591

The 2.4 mm diameter compressed paper rod of the cotton swab with a little amount of IPA (isopropyl alcohol) is just complete fit for cleaning of XLR female connectors. Of course, I dry-up all the connectors with the air duster after the cleaning with IPA.

(You would please refer to my post here and here for the details of the latest system setup.)

I carefully clean-up all the metal-to-metal connectors (male and female), including AC power inlets, XLR and RCA connectors, SP cable Y-lugs and AMP/SP binding posts, SP cabling board screw connections, USB I/O connectors, etc. It takes about four (4) hours to complete the intensive biannual cleaning.
View attachment 240592

View attachment 240593

I usually do it on sunny dry day in early May and late October.

I believe you can easily guess/understand the positive effects of such a complete/intensive cleaning of the connectors actually and/or psychologically audible.
On my active system I never cleaned my RCA contacts and I lost a KEF 107.2 matched tweeter from some kind of dirty contact or static electricity discharge. Not sure what caused it but I do know that I barely touched a RCA cable and a electrical spike went to my tweeter and it did not survive. So I think what you are doing is a good idea for a multi amp active system.
 
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dualazmak

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Hello @Doodski,

I edited/corrected "Biannual" into "Semiannual"! Would you please do the same in your post above? Thank you!
 

MCH

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Biannual Semiannual complete cleaning of all the metal-to-metal connectors

Hello friends,

The day before yesterday, October 30 Sunday in Japan, the autumn clear blue sky with temperature 19 degree C (66 F) and the comfortable dry air (humidity 39 %), was just perfect for my biannual complete cleaning of all the connectors in my audio setup.

I usually use only these items for cleaning of all the metal-to-metal connectors in my audio setup; 100 % isopropyl alcohol, cotton swabs with 2.4 mm diameter compressed paper rod, micro-porous ceramic RCA cleaning rods, dust blower (compressed air duster).
View attachment 240591

The 2.4 mm diameter compressed paper rod of the cotton swab with a little amount of IPA (isopropyl alcohol) is just complete fit for cleaning of XLR female connectors. Of course, I dry-up all the connectors with the air duster after the cleaning with IPA.

(You would please refer to my post here and here for the details of the latest system setup.)

I carefully clean-up all the metal-to-metal connectors (male and female), including AC power inlets, XLR and RCA connectors, SP cable Y-lugs and AMP/SP binding posts, SP cabling board screw connections, USB I/O connectors, etc. It takes about four (4) hours to complete the intensive biannual cleaning.
View attachment 240592

View attachment 240593

I usually do it on sunny dry day in early May and late October.

I believe you can easily guess/understand the positive effects of such a complete/intensive cleaning of the connectors actually and/or psychologically audible.
Hi Dualazmak, thanks for sharing, some day someone will have to print this valuable thread into a reference book :D
Wanted to ask you what is your take about using IPA vs other specialized cleaners that provide some degree of corrosion protection as well (based I believe in fatty acids). Isopropanol is good to clean, and having the contact clean is helps to avoid corrosion, but beyond that (that is a lot, don't miss understand me) once the isopropanol evaporates after a few minutes, your contacts are again exposed.
I personally think it is not very relevant unless you live in an extreme climate or very close to the sea, but as you seem to be a person that takes good care about every detail, I am curious about your choice.
Thanks!
 
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dualazmak

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Wanted to ask you what is your take about using IPA vs other specialized cleaners that provide some degree of corrosion protection as well (based I believe in fatty acids). Isopropanol is good to clean, and having the contact clean is helps to avoid corrosion, but beyond that (that is a lot, don't miss understand me) once the isopropanol evaporates after a few minutes, your contacts are again exposed.

Thank you for your warm words.

I used to use CAIG DeoxIT DN5 spray connector cleaner containing some kind of deoxidant (fatty acids?), but later-on I stopped using it since I found the deoxidant polymerized into a kind of resin-like material, and it even gave a very slight (acidic?) corrosion on some tin plated metals and aluminum parts.

Edit: It would be possible that the long-remaining long-lasting CAIG DeoxIT DN5 on the surface of metals may attract/absorb humidity water vapor (steam) into it might be causing acidic mal-actions to the metals; Japan is rather humid country, especially in rainy season of June to middle of July.

After my long years on audio exploration, I now believe periodical (semiannual or annual) clean-up with 100 % IPA should be the best way to go!
 
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MCH

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Thank you for your warm words.

I used to use CAIG DeoxIT DN5 spray connector cleaner containing some kind of deoxidant (fatty acids?), but later-on I stopped using it since I found the deoxidant polymerized into a kind of resin-like material, and it even gave a very slight (acidic?) corrosion on some tin plated metals and aluminum parts.

After my long years on audio exploration, I now believe periodical (semiannual or annual) clean-up with 100 % IPA should be the best way to go!
Your observations make sense. Your choice of solvent and frequent cleaning is probably the best one. Thanks for the insight.
 
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Just for your info, I have also experienced similar long-range slight acidic metal corrosion/rusting problems with IPA cleaning spray containing silicon polymer oil plus ascorbic acid and/or sodium ascorbate (actually they are Vitamin C!, weak acid) as antioxidant, even though it is/was very safe for our skin (and taste good).
 
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Yems

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Precision measurement and adjustment of time alignment for speaker (SP) units
Part-2: Energy peak matching method


Here, I prepared another test tone signal of 300 ms width consists of multiple-frequency peaks in-single-time-line, just at the center of the time width;
View attachment 179158
Hello dualazmak,

i appreciate your work very much, thank you for your excellent and detailed explanations! I want to do the same tests with my speaker-setup. Would it be possible for you to post a screenshot of the actual sine waves so that i can estimate their duration and shape, since i don't have the Sony Super Audio Check CD?

Regards
Yems

Example:
1667391497138.png
 

MCH

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Just for your info, I have also experienced similar long-range slight acidic metal corrosion/rusting problems with IPA cleaning spray containing silicon polymer oil plus ascorbic acid and/or sodium ascorbate (actually they are Vitamin C!, weak acid) as antioxidant, even though it is/was very safe for our skin (and taste good).
Well, antioxidant and corrosion inhibitor are different concepts that can be related or not, depending on the case, and ascorbic acid can actually be both.

Deoxit is said to be based in Oleic acid. I cannot confirm that as it is not disclosed by the company, but certainly could be and for this example let’s assume it is.
This fatty acid and other different long medium-chain carboxylic are commonly used as corrosion inhibitors (not antioxidants). The way they work, very simplified, is that they attach to the metal surface and form a sort of protective hydrophobic barrier that slows down the corrosion processes.
Oleic acid in particular has an unsaturation in its hydrocarbon chain, and as a result is prone to react little by little with atmospheric oxygen and oligomerize forming the paste or resin you refer to.

Ascorbic acid is a real antioxidant (that is, can donate electrons so that it gets itself oxidized and protects other substances from oxidation. This is a common use of ascorbic acid, for instance, conservative for meat and other things). But besides that it can as well be used as corrosion inhibitor. Similar to the fatty acids, it can also adsorb to the surface of the metal and form a protecting layer.

However the efficiency of any corrosion inhibitor is going to depend on the metal to protect, the corroding medium etc, so it is perfectly possible that in your case the ascorbic acid was not effective enough and you observed some corrosion.
 
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