• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

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

A new series of audio experiments on reflective wide-3D dispersion of super-tweeter sound using random-surface hard-heavy material: Part-2_ Comparison of catalogue specifications of metal horn super-tweeter (ST) FOSTEX T925A and YAMAHA Beryllium dome tweeter (TW) JA-0513; start of intensive listening sessions with wide-3D reflective dispersion of ST sound

Hello friends,

Today, I could manage preparation of comparative representation on catalogue specifications of metal horn super-tweeter (ST) FOSTEX T925A and YAMAHA Beryllium dome tweeter (TW) JA-0513 as shown in this Fig.18.
WS00007197.JPG


As I described in my Part-1 post #911, in my audio setup, the Fq coverages with TW JA-0513 and and ST T925A are well overlapped (they sing together); JA-0513 has ordinary efficiency with good directivity characteristics, while ST T925A has very high efficiency but narrow directivity (typical for metal horn super-tweeters) as you can see in above Fig.18.

I assume (or even believe) this comparative representation in Fig.18 would reasonably explain the favorable contribution of the reflective wide-dispersion ST sound to (slightly) better 3D sound stage/image as well as to wider/larger sweet spot/sphere around my listening position; by the sound dispersion, the directivity of ST sound would become similar to TW, and the possible slight gain-loss of ST sound can be quite easily compensated by the amplifier YAMAHA A-301 directly dedicatedly driving STs.


In any way, today I also started my intensive listening sessions testing/comparing the four reflective dispersion configurations for ST T925A where I use the my default Case-0 (no reflectors) setting as reference sound.

Today, I intensively listened to track-001 through track-005, all of them are full orchestral music, of my consistent "Audio Sampler/Reference Music Playlist" (ref. here #670, #588 (including YouTube links), and this dedicated thread) using the Case-0 through Case-4 settings;
WS00007180.JPG


I found again, similar to the preliminary result of yesterday, that Case-2 setting (i.e. reverse straight reflective dispersion), "most preferably among the four dispersion settings" gave better 3D sound stage/image as well as wider/larger sweet spot/sphere around my listening position for the full orchestral music we tested/evaluated (my wife partly participated).

Yes, very interestingly Case-2 setting is so far so nice...
WS00007179.JPG


You would please note that the crystal-glass reflector of random multiple reflection surfaces/pattern is placed slightly in slant, I mean slightly face upward. This is intending to minimize the reflected sound would go again into the cavity of the ST T925A.

I will slowly and steadily continue our intensive comparative listening sessions during coming several months using my "Audio Sampler/Reference Music Playlist" (ref. #670 and this dedicated thread).
 
Last edited:
OK, thank you for the information.
At least I myself do stick to, however, safe and (almost completely) transparent rather affordable 10 microF capacitors to protect my tweeters and super-tweeters.

Yes, in fact, we use 100 mF cap with a parallel .1 UF silver mica on ours. Zero voltage across it in normal operation (well, under microvolts at least). Yes, we know how to measure.
 
Just for your possible interest and reference...

Partly relating to my current "new series of audio experiments", I just wrote my post #637 on the remote thread "Classical ♫ Music only | Some you listen now or recently, some you love...".
 
Last edited:
A new series of audio experiments on reflective wide-3D dispersion of super-tweeter sound using random-surface hard-heavy material: Part-3_ Listening evaluation of sound stage (sound image) using excellent-recording-quality lute duet tracks

Hello friends,

As I have shared in my post #642 and in many of my posts on another thread “Lute Music and Other Early Music: Stunning Recordings We Love, lute music tracks of excellent recording quality are always nice challenge to our audio system.

As a part of my present series of audio experiments, today I intensively listened to this wonderful excellent-recording-quality lute duet album especially tracks 1 – 4, Sylvius Leopold WEISS: Sonata in C Major by Edward MARTIN and Paul BERGET; I download-purchased the album at MAGNATUNE site in 2004. Of course, all the SP drivers were singing together having the total Fq-SPL at listening position shown in Fig.14 and Fig.15 in my Part-1 post #911.
WS00007201.JPG


Even though the sound quality of the clips would not be optimal, you can hear/listen to the four tracks on YouTube; I highly recommend you to download-purchase the entire album if you would prefer and if you would be interested in this kind of music which are very much suitable for checking reproduction of not only total S/N but also sound stage/image.
Track-1: Andante

Track-2: Allegro I/II

Track-3: Largo

Track-4: Tempo de Minuetto

I usually listen to this download-purchased album with relative +2.7 dB boost in R-channel by DSP-EKIO’s input panel for my preferable L-R balance for the album; I do not know this can be attributable (or not) to either of, or any combination of, these factors:

1. Asymmetry of my listening room furniture and acoustics,
2. Slight off-center alignment of microphone at the recording venue,
3. Slight difference in distances of the two lutenists from the microphone,
4. Difference in personal “gain” preferences of the two lutenists,
5. Essential difference between the two lute instruments,
6. Acoustic asymmetry of the recording venue.

In any way, at least for us (with my wife) +2.7 dB boost in R-channel gives our best L-R balance and very nice allocation of the two lutenists; one lutenist sits at middle of left-to-center, another lutenist sits at middle of center-to-right, both between the L&R speaker system; of course the total hall/recording-venue sound for two lutes are very fantastic and enjoyable.

During the comparative listening session on the four (4) top tracks of this album, I set about +3 dB higher gain using the YAMAHA A-S301 integrated amplifier compared to my standard gain for super-tweeter (ST) sound (with no effect on upstream DSP XO/EQ/Delay/Gain/Phase configuration), since this +3 dB boost in analog domain would very nicely compensate the possible slight gain loss by the wide-3D reflective dispersion of ST sound.

We intensively listened to through the four (4) tracks five times with the Case-0 (no reflector) setting and with Case-1 to Case-4 setting with the glass reflector in front of STs T-925A;
WS00007180.JPG


For checking the “sweet spot / sweet sphere”, we rotated our heads and we actually 3D-moved around the center of my usual listening position (3.2 m away from the SP system).

I should not write too much here about differences of our subjective impression/sensation between the five settings, but I would like to share which setting among the five gave the best total sound reproduction in terms of stable/robust lutenists allocation (sound stage/image) as well as the widest/largest sweet spot/sphere around the center of listening position.

As the results of our intensive subjective listening sessions, we were very much amazed and impressed (again!) by the Case-2 reverse-straight wide-3D dispersion setting for STs gave considerably better/best stable sound stage/image as well as widest/largest sweet spot/sphere around the center of listening position. I can find no suitable wording to describe the wonderful sonority and excellent sound stage (sound image) given by the Case-2 setting which remained almost unchanged even if we considerably moved around; just amazingly nice…

After finishing today’s listening sessions, we (myself and my wife) unanimously agreed that for our further listening evaluations in this new series of audio experiments, we may reasonably exclude the Case-1 (straight against reflector towards us), Case-3 (reverse 45-deg toe-in) and Case-4 (reverse 45-deg toe-out) settings, and we would be better to mainly just compare Case-0 (no reflector) to Case-2 (reverse straight 3D reflective dispersion).

During the coming one month or two, I will slowly and steadily continue our intensive comparative listening sessions using my "Audio Sampler/Reference Music Playlist" (ref. #670 and this dedicated thread) as well as hopefully some other tracks and/or album of my interests; please be reminded, however, that I will share the results less frequently since they would be almost subjective evaluations.

I hope I would share (provisional) conclusion of this series of new audio experiments in my audio system in my acoustic environment by my next possible Part-4 post on this subject to be written within coming two months.

Edit on May 10, 2024:
I assume the below schematic drawing Fig.19 would assist your further understandings of my point on "sound image" in this post;
WS00007267.JPG

The excellent "sound image", i.e. sound allocation of two lutenists, remains unchanged even if we considerably move 3D around the center of my usual listening position (3.2 m away from the surface of the SP system). The wide/large sweet spot (sweet sphere) around the listening position is nicely reinforced/improved by the wide-3D reflective dispersion of the HF sound of super-tweeters which sing together with upper tweeters.
 
Last edited:
A new series of audio experiments on reflective wide-3D dispersion of super-tweeter sound using random-surface hard-heavy material: Part-3.1_ Listening evaluation of sound stage (sound image) using excellent-recording-quality jazz trio album

Hello friends,

As a part of my present series of audio experiments, today I intensively listened to this wonderful excellent-recording-quality jazz trio album "BLUE PRELUDE" by Karel Boehlee Trio; CD MYCJ-30358 M&I JAZZ. Of course, all the SP drivers were singing together having the total Fq-SPL at listening position shown in Fig.14 and Fig.15 in my Part-1 post #911.
WS00007270.JPG


Even though the sound quality would not be optimal, you can hear this album on YouTube;
https://www.youtube.com/playlist?list=OLAK5uy_lq7Nc4gqBIcXQLLsMy24AYYgpmngdmDfw

Here, let me refer to only one of the YouTube album clips; track-4 "High Times":
I have also touched on this track as one of my "Reference/Sampler Music Tracks" in my post #640 showing the Fq-Gain-time color spectrum of the track analyzed by Adobe Audition 3.0.1.

Furthermore, I use this track for sharing the video of dancing DIY 12-VU-Meter Array in my post #753.

The recording sound quality of entire album is really excellent (and very much enjoyable performance, of course!) really suitable for checking our audio system and room acoustics. By listening to this album with my audio system, I can easily understand the intentions of recording/mixing engineer(s) for sound image (sound stage) reproduction given by the CD release.

The drum set (drums and cymbals) is allocated in left-to-center, bass (contrabass) in center, and the main piano sound is allocated/spreaded in front center-to-right. It is interesting to note that, in piano sound, the lower keys are in center-oriented position and the higher keys are in right-oriented position. (Edited and corrected this paragraph on May 10 at 11:41 Japan Time.)

I assume this schematic drawing Fig.20 would assist your further understandings of my point on "sound image" in this post;
WS00007268.JPG


This time, as the objective of my present new series of audio experiments, I intensively and cafarfully tested/evaluated only the Case-2 setting, i.e. the wide-3D reverse-reflective dispersion of super-tweeter (ST) FOSTEX T925A HF (high frequency) sound by the random cut-glass surface of thick-heavy Bohemian glass bowl. Please again be reminded that STs FOSTEX T925A sing together with the upper tweeters (ref. Fig.13, Fig.14, Fig.15 in my Part-1 post #912).

In comparison to the reference setting of Case-0 (no reflector) (ref. Fig.06 in my Part-1 post #912), the Case-2 setting gave better stable and robust "sound image" schematically shown in the above Fig.20 as well as wider/larger "sweet spot/sphere" around the listening position (3.2 m away from the surface of the SP units, ref. Fig.02 of post #912) even if we considerably move 3D around the center of my usual listening position.

Again, the wide/large sweet spot (sweet sphere) around the listening position is nicely reinforced/improved by the Case-2 wide-3D reflective dispersion of the HF sound of super-tweeters which sing together with upper tweeters.

Edit on May 9, 2024 at 19:55 Japan Time
Just for your possible interest, both of the CD albums "LOVE DANCE" (MYCJ-30477 M&I JAZZ, 2008) and "SECRET LIFE" (MYCJ-30561 M&I JAZZ, 2010) by Karel Boehlee Trio have the similar reproduction of "sound stage/image" which I described above for the album "BLUE PRELUDE"; as I shared in my post here, these CDs has slightly better total sound quality (or slightly better "sonority", I may say). I am just now listening to these albums with Case-2 wide-3D reflective dispersion of super-tweeter (ST) FOSTEX T925A HF (high frequency) sound.
You can find several tracks of these albums on YouTube, even though the sound quality of YouTube clips would not be optimal.


 
Last edited:
I edited and corrected one paragraph in the above post #927:
The corrected paragraph is;
The drum set (drums and cymbals) is allocated in left-to-center, bass (contrabass) in center, and the main piano sound is allocated/spreaded in front center-to-right. It is interesting to note that, in piano sound, the lower keys are in center-oriented position and the higher keys are in right-oriented position.

The Fig.20 is correct from the beginning when I prepared/drew.
 
Last edited:
A new series of audio experiments on reflective wide-3D dispersion of super-tweeter sound using random-surface hard-heavy material: Part-4_Provisional conclusion to use Case-2 reverse reflective dispersion setting in default daily music listening

Hello ASR friends,

We, myself and my wife, almost completed our rather intensive comparative listening sessions (repeated several times!;)) between the Case-2 reverse reflective dispersion setting and no reflector ordinary setting throughout all the 60 tracks of my "Audio Sampler/Reference Music Playlist" (summary ref. here #669 #670, and independent thread here).

Throughout our listening sessions, our subjective positive impression remained unchanged which I described in my above post #912, #921, #926 and #927:
In comparison to the reference setting of Case-0 (no reflector) (ref. Fig.06 in my Part-1 post #912), the Case-2 setting gave better stable and robust "sound image" as well as wider/larger "sweet spot/sphere" around the listening position (3.2 m away from the surface of the SP units, ref. Fig.02 of post #912) even if we considerably move 3D around the center of my usual listening position.

As our provisional conclusion at present, therefore, we decided to use the Case-2 reverse straight reflective dispersion setting of high Fq sound from super-tweeters FOSTEX T925A by using heavy-hard Bohemian crystal glass random surface in our default daily music listening at our present room acoustic environments.
WS00007179.JPG


By the way, on August 3 2023, I shared the total system setup in detail in my post #774. After that post, i.e. during the past almost one year period, I introduced/implemented several hardware and software changes/improvements in my audio rig, including the above 3D reflective dispersion of super-tweeter sound, VB-AUDIO MATRIX as system-wide routing center (complete replacement for ASIO4ALL), slight modification in DSP "EKIO" configuration (as system-wide onestop DSP center), etc.

I assume, therefore, now it is good and suitable timing to prepare an intensive update post sharing "the latest system setup as of June 2024"; you would please stay tuned and please look forward to finding such my new intensive overall update post coming hopefully within a week or two.:D
 
Last edited:
The latest system setup of my DSP-based multichannel multi-SP-driver multi-amplifier fully active audio rig, including updated startup/ignition sequences and shutdown sequences: as of June 26, 2024

Abbreviations in this post;
- L&R sub-woofers (SWs),
- L&R woofers (WOs),
- L&R Beryllium-midrange-squawkers (SQs MDs),

(I know nowadays very few people use the word "squawkers", but please let me continue using "SQs" for midrange "MD" drivers.)
- L&R Beryllium-tweeters (TWs),
- L&R metal-horn-super-tweeters (STs),
Each of these is driven directly (with no LCR-network nor attenuator) by dedicated HiFi amplifier; SW has powerful built-in amplifier, and I use four stereo HiFi integrated amplifiers for others.


Hello ASR friends,

I shared the total system configuration/setup last time in my post #774 on August 6 in 2023 just after the introduction of BEHRINGER DS2800 XLR Distributor/Splitter for tweeters and super-tweeters in my audio rig.

After that post, i.e. during past almost one-year period, I introduced/implemented several hardware and software changes/improvements in my audio rig, including the 3D reflective dispersion of super-tweeter sound, VB-AUDIO MATRIX as system-wide routing center (complete replacement for ASIO4ALL), slight modification in DSP "EKIO" configuration (as system-wide one-stop DSP center), complete renewal of SP cabling boards, etc.

I assume, therefore, now it is good and suitable timing to share this rather intensive update post of "the latest system setup as of June 26, 2024" with all of you, not only for your reference and interest but also for my own detailed memorandum on present system setup.

In this post, I continue following my style of “one diagram/photo would worth more than 1,000 words”.

As usual, let me start with the total physical system diagram as of June 26 2024:
Fig01_WS00007535.JPG


If you would like to see inside and outside photos of the four integrated amplifiers, i.e. ACCUPHASE E-460, YAMAHA A-S3000, SONY TA-A1ES and YAMAHA A-S301, please visit my post #38 on a remote thread.

The signal configuration for the DIY-built 12-VU-Meter Array (ref. #535) remained unchanged:
Fig02_WS00007534.JPG

I shared video clips of "dancing" 12-VU-Meter Array in my posts #750, #751, #752 and #753.

As for the revival of vinyl LP player (TT) DENON DP-57L in my DSP-based digital multichannel audio rig for on-the-fly listening to vinyl LP, please refer to my post #688 and #697.

The latest total signal path with JRiver MC32 as master volume controller:
Fig03_WS00007533.JPG


I had slight modifications in DSP EKIO’s EQ and gain settings for which I will touch on later in this post.

My DAC8PRO's firmware is ver.1.32, and the DIYINHK ASIO USB driver is ver.4.59.0 provided by OKTO when I got DAC8PRO in May 2020; still working perfectly fine on Windows 11 Pro.

Please refer to posts #248 and #251 for the fine tuning parallel 22 Ohm resistors in SQ (MD), TW, ST speaker-high-level signals.

You would please refer to my posts #245 and #901 for protection capacitors in SQ (MD), TW, ST speaker-high-level circuits, and also refer to post #402 and #485 for the 1.5+1.5=3 microF high-pass (low-cut) capacitors in SP high-level signal for ST.

The details of incorporation of BEHRINGER DS2800, HiFi-grade active XLR balanced line-level signal splitter/distributor (ref. #769):
Fig04_WS00007532.JPG

Note: You would please be reminded that Even Greg Timbers uses "reasonable and budget" small integrated amplifier Pioneer Elite A-20 (low THD, high S/N, RCA unbalanced input, 30W+30W [20Hz-20kHz, THD0.05%, 8 ohms]) for ultra-high Fq compression drivers (super tweeters) in his extraordinary expensive multichannel stereo system with JBL EVEREST DD67000 which he himself designed and developed: please refer to my post here #435.

In DS2800, I leveled-up the gain +3 dB going into YAMAHA A-S301(dedicatedly driving STs) to compensate slight gain loss (at my listening position) due to the 3D reflective dispersion (will touch soon in this post) of ST super-tweeter sound, so that I have no change in default volume position of A-S301 driving STs.

Here in this post, please let me emphasize again about the pros and merits of relative gain (i.e. tone) control not only in digital domain but also in analog domain using pre-amplifiers or integrated-amplifiers (in my setup). I recently wrote again in my post #56 on a remote thread like these;
Yes, as for safe and flexible tone controls (or I can say "relative gain controls among the multiple SP drivers"), my stance (policy) at least, is that we are encouraged to utilize the "best combination" of "DSP configuration in digital domain" and "analog domain tone controls using HiFi-grade preamplifiers and/or integrated amplifiers".

We need to note (and to respect for) that analog domain tone controls (relative gain controls among the multiple SP drivers) give no effect nor influence at all on the upstream DSP configuration (XO/EQ/Gain/Phase/Polarity/Group-Delay). I believe that this is a great merit of flexible tone controls in analog domain. We know well, on the other hand, in case if we would like to do the "tone/gain controls" only within DSP configurations, such DSP gain controls always affect more-or-less on "XO" "EQ" "phase" and "delay" of the DSP settings which will leads you to possible endless DSP tuning spirals every time; within DSP configurations, XO EQ Gain Phase and Delay are always not independent with each other, but they are always interdependent/on-interaction.

Just for your possible reference, my DSP-based multichannel multi-SP-driver multi-amplifier active system has flexible and safe analog level on-the-fly relative gain controls (in addition to upstream on-the-fly DSP gain controls) for L&R subwoofers, woofers, midrange-squawkers, tweeters, and super-tweeters, all independently and remotely.
My post here shows you a typical example case for such safe and flexible on-the-fly analog-level tone controls. This my post
(as well as this post) would be also of your interest.

Of course, I know well that I (we) can also perform such relative gain control using DAC8PRO’s 8-channel output gain controllers. I do not like, however, to change the DAC8PRO’s output levels frequently on-the-fly (while listening to music) due to safety and inconvenience concerns; I like to keep DAC8PRO’s analog out gain level always at constant -4 dB which should remain to be usually “untouchable” in my case.

One of the very unique aspects/features of my multichannel audio rig is that I fully utilize four HiFi-grade “integrated amplifiers” plus L&R active subwoofers, each of them have its own gain (volume) controller for safe and flexible relative gain (tone) control in analog domain even on-the-fly i.e. while listening to music.

In this perspective, my posts #438 and #643 should also give you better understandings. Furthermore, my posts #317(remote thread), #313(remote thread) would be also of your reference and interest.


In November 2023, I intensively tested and decided to utilize VB-AUDIO MATRIX as system-wide ASIO/VASIO/VAIO routing center which has fully replaced ASIO4ALL I have been using until then.

After the introduction of VB-AUDIO MATRIX, it also provides Virtual Audio I/O device, VAIO, in Windows 11 Pro audio configuration where I can select VAIO4 as Windows’ default sound play device so that all the sound signals can be handled/processed with VB-MATRIX and DSP “EKIO”:
Fig05_WS00007531.JPG


In this update post, I believe that I should share the details of VB-AUDIO MATRIX behaving as system-wide ASIO/VASIO/VAIO routing center; I hope the following four diagrams would be self-explanatory for your easy understandings:
Fig06_WS00007530.JPG


Fig07_WS00007529.JPG


Fig08_WS00007528.JPG


VB MATRIX and DSP EKIO are also fully active even for live (on-the-fly) vinyl LP listening:
Fig09_WS00007527.JPG



Next, let’s move on to the latest DSP “EKIO” configuration after the introduction of VB MATRIX; hereinafter in this thread post, 88.2 kHz 24bit configuration in VB MATRIX, DSP “EKIO” and JRiver MC32 will be shared.
- Summary of rationales for "on-the-fly (real-time)" conversion of all music tracks (including 1 bit DSD tracks) into 88.2 kHz or 96 kHz PCM format for DSP (XO/EQ) processing: #532

For I/O to/from EKIO, now I can select VB MATRIX’s VASIO-64A I/O channels:
Fig10_WS00007526.JPG


The latest details of I/O panels in EKIO;
Fig11_WS00007525.JPG

As for the 0.1 msec precision "group delay settings" or "time alignment" over all the SP drivers, please refer to posts #493, #494, #504, #507, as well as these two posts under the spoiler cover:
- Perfect (0.1 msec precision) time alignment of all the SP drivers greatly contributes to amazing disappearance of SPs, tightness and cleanliness of the sound, and superior 3D sound stage: #520
- Not only the precision (0.1 msec level) time alignment over all the SP drivers but also SP facing directions and sound-deadening space behind the SPs plus behind our listening position would be critically important for effective (perfect?) disappearance of speakers: #687

And the details of EKIO's XO/EQ configuration:
Fig12_WS00007541.JPG


Now I added very mild +3 dB Q=1 at 84 Hz Bell EQ for woofers which gives slightly better sound in SW (sub-woofers) to WO (woofers) transition/overlap Fq range, even though the gain and relative-gain of SW and WO can be further flexibly controlled in analog domain.

In the EKIO’s output panel, now I set +8 dB for KORG DS-DAC-10 monitoring the whole-sum signal gain into physical VU-Meter 01 and 02 through headphone out under the volume control dial of DS-DAC-10 for flexible VU swing gain adjustment.

I also set +9 dB for SWs in EKIO’s output panel; please note that my L&R heavy-large SW YST-SW1000 has its own volume control can be increased/reduced by remote controller from my listening position.
- Reproduction and listening/hearing/feeling sensations to 16 Hz (organ) sound with my DSP-based multichannel multi-SP-driver multi-amplifier fully active stereo audio system having big-heavy active L&R sub-woofers: #782
- A nice smooth-jazz album for bass (low Fq) and higher Fq tonality check and tuning: #63(remote thread)

As for the -48 dB/Oct low-pass (high-cut) filters at 25 kHz for SQ(MD), TW, ST drivers…
- "Near ultrasound - ultrasound" ultra-high frequency (UHF) noises in improperly engineered/processed HiRes music tracks, and EKIO's XO-EQ configuration to cut-off such noises: #362-#386, #518, #532

I usually use JRiver MC32 (as of July 1 2024 ver.32.0.55, 64-bit) as my default music (and AV) player with on-the-fly conversion of all the audio signals into 88.2 kHz (or 96 kHz) 24-bit PCM format, and JRiver’s audio output device is “VB-AUDIO VASIO-64A (ASIO)”;
Fig13_WS00007523.JPG


Even though I have above mentioned several changes/modifications, the best tuned room air SLP curve (in my standard/default setting) measured at my listening position remained unchanged while all the L&R SP drivers sing together;
Fig14_WS00007522.JPG


As for the cross-calibration profile of my specially selected measurement microphone BEHRINGER ECM8000, you would please refer to my post #831.

Of course, I also measured/checked Fq responses of audio signals at various “stages” in digital domain, analog domain, and real room air sound at my listening position.
Please refer to this summary post and the linked posts thereof;
- Frequency (Fq) responses in the completed system measured by using “cumulative white noise averaging method” under the present standard crossover configurations and relative gains_Part-6_Summary, discussions, and a little step forward: #404, #405-#409

The below Fig.15 shows the standard/default software layout on audio dedicated 27” PC monitor screen for daily music listening sessions. In this layout, I can see/monitor all the peak bar meters of JRiver MC, VB-AUDIO MATRIX main panel, VB MATRIX Routing Grid, and DSP EKIO. Furthermore, as also shown in Fig.15, the DIY-built 12-VU-Meter Array monitors gain of the whole sum line-level signal, line-level input into L&R active sub-woofers (SWs), and each of the amplifiers’ SP high-level output signals driving woofers (WOs), midrange-squawkers (MDs/SQs), tweeters (TWs) and super-tweeters (STs).
WS00007632.JPG


For occasional further intensive measurements (using cross-calibrated BEHRINGER ECM8000 microphone, ref. #831) and fine-tuning sessions, I bring my Xeon CPU (ES-2630 v3) PC-workstation from upstairs office into the opened sound deadening space (room) behind my listening position (ref. #687) together with two of 27” EIZO EV2750 monitor (2560 x 1440 pixel) giving 5120 x 1440 pixel desktop area; on the wide-large desktop area, I can spread with no overlap all of the relevant software tools/utilities like DSP EKIO, VB-Audio MATRIX (Main Panel and Routing Grid), JRiver MC32, MusicScope 2.1.0, Adobe Audition 3.0.1, many ASIO control panels, etc.


Let’s move on to the latest setup of SP system.
Fig16_WS00007520.JPG


The major and only modification during past one year is/was the reverse wide-3D reflective dispersion of sound from STs (metal horn super-tweeters) by using random-surface hard-heavy-thick crystal-cutglass bowl which gives better stable and robust "sound image" as well as wider/larger "sweet spot/sphere" around the listening position, even if we considerably move 3D around the center of my usual listening position.
- A new series of audio experiments on reflective wide-3D dispersion of super-tweeter sound using random-surface hard-heavy material:
___Part-1_ Background, experimental settings, initial preliminary listening tests: #912
___Part-2_ Comparison of catalogue specifications of metal horn super-tweeter (ST) FOSTEX T925A and YAMAHA Beryllium dome tweeter (TW) JA-0513; start of intensive listening sessions with wide-3D reflective dispersion of ST sound: #921
___Part-3_ Listening evaluation of sound stage (sound image) using excellent-recording-quality lute duet tracks: #926
___Part-3.1_ Listening evaluation of sound stage (sound image) using excellent-recording-quality jazz trio album: #927
___Part-4_Provisional conclusion to use Case-2 reverse reflective dispersion setting in default daily music listening: #929

Fig17_WS00007519.JPG


Fig18_WS00007518.JPG


The details of ST FOSTEX T925A metal horn super-tweeter and the sound reflector, i.e. heavy-hard-thick Bohemian crystal cutglass bowl with random outer surface;
Fig19_WS00007517.JPG


The dimension/distance of listening triangle;
Fig20_WS00007516.JPG


You would please note that I have nice open space (actually our dining room) behind/between the L&R SP system (no sound reflex port in rear of the SP system), and I also have preferrable sound deadening space (actually Japanese style tatami floor room) behind my listening position.
- Not only the precision (0.1 msec level) time alignment over all the SP drivers but also SP facing directions and sound-deadening space behind the SPs plus behind our listening position would be critically important for effective (perfect?) disappearance of speakers: #687

As I shared in my post #311 and #111 (remote thread), the ceiling of our living/listening room is covered by microporous diatom panels carefully selected with proper sound absorption performance, and on the floor we have carpet reducing/minimizing sound reflection and resonance/standing-wave.

Please refer to post #84 and #497 for the cabinet and drivers of YAMAHA NS-1000 (not NS-1000M). Also in posts #497 and #782, you can find spec info on SW YST-SW1000. Please refer to #485 for overhaul maintenance of ST T925A.

As for the unique positioning of ST T925A (beneath the WO), please refer to my post #27.

Again, as for the 0.1 msec precision perfect time alignment between all of the SP drivers, please refer to my posts #493, #494, #504, #507 and #520.

You would please find transient characteristics objective measurement data of 30 cm WO JA-3058 and SW YST-SW1000 in posts #495, #503 and #507.

We can easily move/rotate, thanks to the DIY-ed big rubber casters with stoppers, the PANASONIC 55” 4K OLED TV TH-55HZ1800 in our dining room so that it faces to the listening room between the L&R SP system; it can serve as second full-color PC monitor of audio (audio-visual) dedicated PC of 4K (3840x2160 pixel) resolution, refresh rate 60 Hz, by using single slim 10-m-long optical HDMI cable.
Fig21_WS00007515.JPG

You would please refer to my post here #509 (remote thread) regarding a kind of “reverse thinking” utilization of 4K OLED TV connected to PC in DSP-based multichannel audio rig for viewing and listening TV program and other video (YouTube, etc.), DVD movie, blue-ray-Disc movie, and so on.

Up on the very rigid and heavy almost antique cupboard cabinet in my left-hand side when I sit on listening sofa, you can find these audio gears;
Fig22_WS00007514.JPG


I assume you need gear identifications like in this photo;
Fig23_WS00007513.JPG

Again, if you would like to see inside and outside photos of the four integrated amplifiers, i.e. ACCUPHASE E-460, YAMAHA A-S3000, SONY TA-A1ES and YAMAHA A-S301, please visit my post #38 on a remote thread.

Dimension shown together with ruler;
Fig24_WS00007512.JPG


As I recently wrote again here #89 (remote thread), I do not use audio rack (regardless of luxury expensive one or not) at all, but I do “the way” shown above.

The large heavy and physically slightly warm (around my body temp) ACCUPHASE E-460 (24.4 kg, directly driving midrange SP drivers) and DENON DCD-3500RG (22.0 kg, seldom powered-on nowadays) serve as very stable and rigid base for my TT (turn table) DENON DP-57L in 1,430 mm above the floor for occasional (once in two months, or less) vinyl LP ceremonies (ref. my post #758); the position/height of the TT is very nice to "see and check" the stylus of the MC cartridge going down automatically to the surface of LP (I am 173 cm tall). YAMAHA A-S3000 (24.6 kg) is also large and heavy.

Several of my ASR friends repeatedly requested the backside wiring view, and this is “it” as of January 1 in 2024;
Fig25_WS00007511.JPG


After that, I recently renewed all the Y-lugs (crimp Y-terminals) of the SP cables together with heat-shrink insulator covers (ref. #895);
Fig26_WS00007510.JPG


Consequently, here is the latest view of SP binding posts of the four amplifiers;
Fig27_WS00007509.JPG


I also recently fully renewed (ref. #906) the L&R SP cabling board having the protection capacitors, HP (low-cut) capacitors for STs, tuning 22 Ohm resistors, and 100W 8 Ohe dummy SP resistors. This diagram Fig.28 shows that “SP cabling board portion” in the total signal path already shared in above Fig.03;
Fig28_WS00007508.JPG


The fully renewed SP cabling boards placed behind the L&R SP system are shown in this Fig.29;
Fig29_WS00007507.JPG


And the angle view/shot of the new SP cabling board;
Fig30_WS00007506.JPG


I carefully measured/checked these protection capacitors are transparent (inaudible) as shared in my posts #402 and #485. For the “needs” of these protection capacitors, please refer to my post #901.

As for the reason and rationales of 22 Ohm parallel resisters for SQ (MD), TW and ST, you would please refer to my posts #248, #251, #99(remote thread), #100(remote thread), #101(remote thread).

Several of ASR friends also repeatedly requested wiring view in backside of SP system;
Fig31_WS00007505.JPG


I still keep the currently-not-in-use "LCR passive network in outer-box " (ref. #5) for easy and smooth role back of the whole audio system into my reference single-amplifier (ACCUPHASE E-460) passive configuration together with the connection changes on the "SP cabling boards".

I once have tested “Multi-Terminal Electromagnetic Relay” and “Multi-Terminal Snap-Toggle Switch” for this purpose (i.e. switching the wires between passive and active SP modes), but I found they gave some “uncleanliness and/or distortions” to the total sound. Consequently, I believe that the “physical screw-up cabling connections” like in these SP cabling boards should be the best way to go with. I carefully and completely eliminated, therefore, any magnetic susceptible (magnetizable) metal, such as screws, Y-lugs, metal plate on terminal straps, etc. in SP high-level signal wiring; please refer to my post #4, #250 and posts #013(remote thread), #023(remote thread) and here #9(remote thread).

You would please be reminded "the typical issue case" in this regard (even with no relation at all to my project thread) happened with first version of BUCKEYE 3 Channel Purifi Amplifier in which measurable (and I think audible) distortion was caused by iron (steel) plates at the SP binding posts, then BUCKEYE quickly and nicely replaced the parts with brass plates by a kind of recall announcement; please refer to the specific thread on that amplifier, amirm’s first review pointing the issue, as well as his second preferrable review on the fixed/revised amplifier.

Furthermore, in my post #9 on a remote thread "Ferromagnetic materials in audio connectors", I also wrote as follows;
If you take a look inside some rather high-end HiFi amplifiers, you'll see that the SP output wiring (and power wiring?) uses non-magnetic terminals and screws made of brass (no iron at all) or pure copper. However, this is also a common-sense measure to prevent sound quality deterioration in HiFi amplifiers. I remember it being pointed out and explained in interviews with a Yamaha amplifier designer and a Rotel engineer. It is frustrating when working with magnetized screwdrivers (screwdrivers) because you can't catch the screws, though. Yamaha's and Rotel's amplifier designers had a hard time persuading the assembly workers at the amplifier factories, but in the end, they convinced them to use non-magnetic terminals and screws, giving priority to sound quality; I've also heard that the screwdriver, which uses a chuck to fix screws and bolts to the tip, was devised so that it could be used in factories. In my DIY audio setup, I have the same thing; I strictly/completely eliminate/avoid any magnetizable metal/screw in my SP cabling/connecting.


Oh, I have not yet shared in this post the signal path for live (on-the-fly) listening to vinyl LP by JRiver MC’s “Open - Live” listening to the specific ASIO input from audio-interface TASCAM US-1x2HR; here the master volume role of JRiver MC is still alive, and of course DSP EKIO serves as system-wide one-stop DSP center;
Fig32_WS00007504.JPG


Please note that I (we) can connect not only LP player but also any of (old?) "analog line level output only" audio devices to US-1x2HR for on-the-fly listening with my multichannel multi-amplifier setup (and for digital recording, if needed). As for digital recording, I can use any of recording software which can digitally hear the US-HR ASIO Line-in, such as Audacity and Adobe Audition.

I continue using two of rather outdated “completely silent” dedicated PC in my audio(-visual) rig; Fig.33 shows the latest info on the two PCs which are just backup PC with each other; I can change/switch the PC within less than 5 min, the sound quality, of course, is excellent and identical in both of the two PCs having exactly the same OS and software configurations.
Fig33_WS00007503.JPG


Nowadays, I comfortably use two of COOIDEA USB2.0 Volume/Track-Jump Controller connected to the PC using two of slim 12m-long USB 2.0 repeater-extension-cable coming through under the floor carpet.
Fig34_WS00007502.JPG

As shown in the above Fig.34, one controller is on the listening low table, and another one on my ergometer workout bicycle usually set just behind the listening sofa so that both me struggling on the ergometer bike and my wife relaxing on the listening sofa (true for vice versa) can control the master volume and/or jump back/forward the album tracks, of course regardless of the mouse cursor position on the monitor screen. (I usually do not like Bluetooth and other wireless connection of USB devices, except for keyboard and mouse.)


The latest "startup/ignition sequences" and "shutdown sequences" as of June 26, 2024
Having the latest system configuration as of June 26 in 2024 shared above, I also would like to update my post #776 dated August 7 2023 on “Startup/Ignition Sequences” and “Shutdown Sequencies”.

A few of my dear ASR friends have contacted me asking about standard startup/ignition sequences and shutdown sequences in the multichannel multi-amplifier system together with JRiver MC (or Roon) and software crossover EKIO running on Windows 11 PC.

They were a little bit concerned about the maximum protection of speaker drivers from possible unexpected accidental pop damage, and I fully understand their worries even though I have the protection capacitors for midrange Beryllium-dome-squawkers (MDs), Beryllium-dome-tweeters (TWs) and metal-horn-super-tweeters (STs).

Although I daily perform these very familiar (to me) sequences almost unconsciously, I believe it would be worthwhile sharing the sequences with all of you visiting this thread.

Standard "Startup/Ignition Sequences":
01. Wake-up the AC Circuit Breaker (100V/15A if it has been shut-down)
02. Power-on the root switch of 24-port AC power strip (series of four 6-port strips)
______This automatically wakes up DIY-12-VU-Meter-Array, KORG DS-CAC-10, BEHRINGER DS2800
03.
Power-on YAMAHA A-S3000 after making sure the volume is at -infinity dB (no sound)
04. Power-on ACCUPHASE E-460 after making sure the volume is at -infinity dB (no sound)
05. Power-on SONY TA-A1ES after making sure the volume is at -infinity dB (no sound)
06. Power-on YAMAHA A-S301 after making sure the volume is at -infinity dB (no sound)
07. Power-on L&R sub-woofers YAMAHA YST-SW1000 by remote controller (preset volume 13:00 O'clock, 1 p.m.)
08. Power-on OKTO DAC8PRO; make sure the volume (master gain) is less than -75 dB
09. Power-on Windows 11 Pro PC
10.
Check & confirm wake-up and running of VB-AUDIO MATRIX at taskbar
11. Check & confirm wake-up and ready of DIYINHK ASIO at taskbar
12. Check & confirm all the Window's sound I/O (KERNEL, WASAPI, WMD, Mic, etc.) are muted-off
13. Launch DSP EKIO having default preset configuration
14. Launch JRiver MC (or Roon); make sure the master volume is at about 5 % (-77.5 dB)
15. Properly layout VB-AUDIO MATRIX, its Routing Grid view, JRiver MC32 and EKIO’s I/O Panel on PC monitor screen so that all the peak bar-meters can be seen/monitored (as shown in Fig.15)
16. Start playing JRiver e.g. the 6th track of my music sampler/reference playlist (piano solo)
17. Slightly volume-up JRiver to around 10 % (-55.0 dB); check the JRiver's small VU-EQ meter is properly dancing
18. Start “playing” EKIO
19.
Check and confirm that all the EKIO's I/O VU meter bars and all the VB-AUDIO MATRIX Routing Grid VU meter bars are properly moving in exceptionally low gain
20. Volume-up A-S3000 to 11:55 o'clock (-18 dB)
21. Volume-up E-460 to -19.0 dB
22. Volume-up TA-A1ES to -17.0 dB
23. Volume-up A-S301 to 09:45 o'clock (ca. -19 dB)
24. Volume-up DAC8PRO to -4 dB; check to properly hear the sound in small volume
25. Carefully and slowly volume-up JRiver MC (as master volume) to usual listening volume using mouse wheel or COOIDEA USB volume controller

Standard "Shutdown Sequences":
01. Stop playing JRiver MC
02.
Volume-down the "Master Volume" of JRiver MC to less than 5% (-77.5 dB)
03. Stop playing DSP EKIO
04.
Volume-down OKTO DAC8PRO to -99 dB
05. Volume-down YAMAHA A-S301 to -infinity dB (no sound)
06. Volume-down SONY TA-A1ES to -infinity dB (no sound)
07. Volume-down ACCUPHASE E-460 to -infinity dB (no sound)
08. Volume-down YAMAHA A-S3000 to -infinity dB (no sound)
09. Power-off A-S301
10.
Power-off TA-A1ES
11.
Power-off E-460
12.
Power-off A-S3000
13.
Power-off L and R active sub-woofers YAMAHA YST-SW1000 by remote controller
14. Exit/Shutdown JRiver MC
15.
Exit/Shutdown EKIO
16.
Shutdown VB-AUDIO MATRIX
17.
Shutdown Windows 11 Pro PC
18.
Soft-shutdown (Mute-off) OKTO DAC8PRO by remote controller
19. Switch-off the root switch of 24-port AC power strip (series of four 6-port strips)
______This automatically shutdowns DIY-12-VU-Meter-Array, KORG DS-CAC-10, BEHRINGER DS2800
20.
Down the AC Circuit Breaker (100V/15 A, if needed for prolonged shutdown; longer than a week or so)

Although these sequences may look somewhat complicated at your first glance, I usually complete the startup/ignition sequences in less than 3 minutes, and I complete the shutdown sequences in less than 1 minute. I believe you can agree with me that triggered simultaneous startup/power-on with pre-fixed audible gain/volume levels should be definitely avoided at least in my multichannel multi-amplifier audio setup.


Appendices
For your convenience, you would please find Hyperlink Index for this lengthy project thread in my post #444 and the same on independent thread here.

I assume the posts under these spoiler covers would be also of your reference and interest:
You would please refer to my post #4 on a remote thread.
You would please refer to my post #21 on a remote thread.
I wrote there;
It is really heart-a-pain hearing about your experience of flooding. I too am living in the land of typhoon, earthquake and tsunami; I keep multiple backups, therefore, of my entire digital library in several HDDs and NAS at my home and also in remote at my daughter's home and son's (300 km and 100 km away!). Of course, I periodically update the remote backups at least once in 6 months.
Fortunately my current iron-frame house is on a little hill with solid ground, but no way to avoid possible mega earthquake (once in 600 years?) which might happen any place in Japan...

Your visits and participations on these independent threads hosted by myself will be also highly welcome;
- An Attempt Sharing Reference Quality Music Playlist: at least a portion and/or whole track being analyzed by 3D color spectrum of Adobe Audition
- https://www.audiosciencereview.com/...by-3d-color-spectrum-of-adobe-audition.47103/

- Music for Testing Treble (High Frequency) Sound
- https://www.audiosciencereview.com/...or-testing-treble-high-frequency-sound.50690/

- Apparent power consumption of whole audio system during daily audio listening sessions: how SDGs-friendly is it? (not the idle power, please.)
- https://www.audiosciencereview.com/...iendly-is-it-not-the-idle-power-please.51987/

- Lute Music and Other Early Music: Stunning Recordings We Love
- https://www.audiosciencereview.com/...arly-music-stunning-recordings-we-love.21247/

Edit and Addition on August 19, 2024:
- Let's share diagrams (and photos) of our total physical audio system and the whole signal path, with a few words and/or links

- https://www.audiosciencereview.com/forum/index.php?threads/lets-share-diagrams-and-photos-of-our-total-physical-audio-system-and-the-whole-signal-path-with-a-few-words-and-or-links.56410/
 
Last edited:
Last edited:
Although these may look somewhat complicated at your first glance, I usually complete the startup/ignition) sequences in less than two minutes, and I complete the shutdown sequences in less than one minute.;)
Thank you for your postings of your system… I seriously enjoy the photos and explanations!

Tillman
 
Thank you for your postings of your system… I seriously enjoy the photos and explanations!

Tillman

I highly appreciate your kind attention on my project thread.

Although I notice you kindly referred to my post #776 written on August 7 2023, the latest system setup as of June 26 2024, including the revised startup/ignition and shutdown sequences, can be found in my recent post #931.;)
The latest system setup of my DSP-based multichannel multi-SP-driver multi-amplifier fully active audio rig, including updated startup/ignition sequences and shutdown sequences: as of June 26, 2024: #931

Thank you again, with my best regards...
 
Last edited:
Hello, congratulations on such an impressive and complex audio system, as well as on your precise description (122.000 words). I would like to ask about the acoustic principles behind your crossover design. Specifically, which type of acoustic filter did you use in the design of your four-way speaker system—such as a Linkwitz-Riley or a Butterworth, and of which order
 
Back
Top Bottom