Simulation of a 3-way speaker with a cardioid pattern
Hello everyone, I am trying to run simulations in Vituix, with the aim of creating a 3-way speaker with a cardioid pattern. I started by tracing the speakers from the manufacturers' websites, then applied the low-frequency loading and baffle diffraction using the various tools that Vituix offers. My goal is to replicate the speaker to see if I can achieve reliable simulations with what I have designed and measured.
I will post a couple of graphs to share the simulation results and perhaps get suggestions for improving the whole setup.
The speaker will be a stand-mounted design, with dimensions of approximately 40/45cm in height, 35cm in depth, and 20cm in width. The tweeter and midwoofer will be placed on the front panel axis, while the two subwoofers will be positioned on the two side panels.
The crossover will be active, and the goal of the project, in addition to evaluating the quality of the simulation, will be to attempt to simulate an active cardioid system using the two side subwoofers.
Many thanks
Stefano
I will post a couple of graphs to share the simulation results and perhaps get suggestions for improving the whole setup.
The speaker will be a stand-mounted design, with dimensions of approximately 40/45cm in height, 35cm in depth, and 20cm in width. The tweeter and midwoofer will be placed on the front panel axis, while the two subwoofers will be positioned on the two side panels.
The crossover will be active, and the goal of the project, in addition to evaluating the quality of the simulation, will be to attempt to simulate an active cardioid system using the two side subwoofers.
Many thanks
Stefano
Wharfedale Triton crossover
I recently purchased some Wharfedale Triton speakers off eBay, with the intention of refurbishing them as a learning exercise. Essentially a practice pair of speakers, to learn how to clean the grille cloth, rewire and re-cap, that kind of thing. They came with a captive speaker cable that was terminated with a two pin DIN plug. Without thinking, I just chopped those off, as the little amplifier I use to test things only takes bare wire. I naively assumed that there would be some +ve / -ve type marking on the crossover circuit board inside, which it turns out there isn’t.
Here's the speakers in question:
A top view of the crossover, note that two of the inductors are missing any indication of value:
A mirrored view of the bottom of the crossover after I'd de-soldered all the leads:
I took some photos and attempted to try and understand the circuit, so I could determine the correct pins to wire up to some proper terminal posts. I started on a whiteboard, then tried to convert that into a “proper” circuit diagram. I’m new to all of this kind of thing, and am not sure that I’ve used all the correct symbols and terminology on the diagram; I would welcome some feedback on that.
My whiteboard circuit:
And the resulting circuit diagram:
Could someone please confirm whether my circuit diagram is accurate…? Specifically, I would like to verify that I have correctly identified the positive and negative input terminals on the circuit board. That would be the right most tab being the positive input, and the one to it's left, being the negative input.
Cheers,
Bob.
Here's the speakers in question:
A top view of the crossover, note that two of the inductors are missing any indication of value:
A mirrored view of the bottom of the crossover after I'd de-soldered all the leads:
I took some photos and attempted to try and understand the circuit, so I could determine the correct pins to wire up to some proper terminal posts. I started on a whiteboard, then tried to convert that into a “proper” circuit diagram. I’m new to all of this kind of thing, and am not sure that I’ve used all the correct symbols and terminology on the diagram; I would welcome some feedback on that.
My whiteboard circuit:
And the resulting circuit diagram:
Could someone please confirm whether my circuit diagram is accurate…? Specifically, I would like to verify that I have correctly identified the positive and negative input terminals on the circuit board. That would be the right most tab being the positive input, and the one to it's left, being the negative input.
Cheers,
Bob.
![PXL_20250325_202858459.RAW-01.MP.COVER[1].jpg](/community/data/attachments/1348/1348055-09583308872285fe6518e5759550b66f.jpg?hash=dWEA0eTIVL)
Experimental Distortion Matrix
- Solid State
- 0 Replies
Guitar Distortion Matrix
Here’s a circuit that provides a variety of distortion sounds for the electric guitar. The passive diode matrix should be driven by an active device, such as a volume-boosting stomp-box or guitar preamp, while the output can go to any kind of guitar-amp or other such active device. The design is based on the distortion circuit in a project called the “Mod Box” that appeared in Electronics Now magazine in 1997 (May issue, p. 45). And while the article is old, the circuit I designed based on it remains perfectly valid.
The preferred sounds, emphasizing even-order harmonics, with either the Fuzz, Buzz, or Overdrive settings is to activate only one diode oriented in a given direction but two in the other direction. It does not matter which directions are chosen for the combination as long as there’s an imbalance. Of course, any setting provides distortion. The germanium diodes, in the Fuzz setting, are said to give the most pleasing distortion, similar to that of a vacuum-tube clipping, while the silicone diodes give a harder sound, with the LEDs the brightest.
Because of significant loss of input signal level to achieve the distortion effect, some kind of active device, such as a stomp-box with extra gain, is needed on the input. Or, to turn this into an active project, battery-powered solutions are shown below. Use the preamp to drive the matrix and put the buffer between the matrix output and the input of an amplifier or other active device. And I recommend keeping the input/output jacks as shown, to allow for the greatest versatility, even if everything is put in one enclosure. For the +9V DC supply, connect the negative end of a transistor battery to ground so the positive end is the supply. And one battery will serve both circuits.
EOF
Here’s a circuit that provides a variety of distortion sounds for the electric guitar. The passive diode matrix should be driven by an active device, such as a volume-boosting stomp-box or guitar preamp, while the output can go to any kind of guitar-amp or other such active device. The design is based on the distortion circuit in a project called the “Mod Box” that appeared in Electronics Now magazine in 1997 (May issue, p. 45). And while the article is old, the circuit I designed based on it remains perfectly valid.
The preferred sounds, emphasizing even-order harmonics, with either the Fuzz, Buzz, or Overdrive settings is to activate only one diode oriented in a given direction but two in the other direction. It does not matter which directions are chosen for the combination as long as there’s an imbalance. Of course, any setting provides distortion. The germanium diodes, in the Fuzz setting, are said to give the most pleasing distortion, similar to that of a vacuum-tube clipping, while the silicone diodes give a harder sound, with the LEDs the brightest.
Because of significant loss of input signal level to achieve the distortion effect, some kind of active device, such as a stomp-box with extra gain, is needed on the input. Or, to turn this into an active project, battery-powered solutions are shown below. Use the preamp to drive the matrix and put the buffer between the matrix output and the input of an amplifier or other active device. And I recommend keeping the input/output jacks as shown, to allow for the greatest versatility, even if everything is put in one enclosure. For the +9V DC supply, connect the negative end of a transistor battery to ground so the positive end is the supply. And one battery will serve both circuits.
EOF
AIYIMA YM91R20-2F-ZXJ-L1 (3", full range)
- By nandappe
- Full Range
- 15 Replies
AIYIMA YM91R20-2F-ZXJ-L1 (3", full range) installed in HB-07F-ML (double bass reflex).
It is a low-priced product, but it has a die-cast basket and neodymium magnet.
The sound quality is better than the price. Cost performance is high.
Login to view embedded media
It is a low-priced product, but it has a die-cast basket and neodymium magnet.
The sound quality is better than the price. Cost performance is high.
Login to view embedded media
Attachments
Advent Maestro speaker question
- By Tube Radio
- Multi-Way
- 57 Replies
I've got a pair of Advent Maestro speakers that were given to me today. They are in good condition and the woofers were refoamed a few years ago.
I already ordered new caps for the crossover.
Two things I've noticed.
1. The speaker wire terminals on both speakers has separated from the terminal cup with the crossover on it at the bottom. What should I use to secure it back down?
2. I've read where the woofer doesn't play high enough causing a hole in the frequency response near the crossover point of the woofer and midrange which is 900Hz. Listening to them, I believe I actually hear that, but will wait until the film caps come in and are installed to see if that fixes it. If I still hear the issue, what is the best way to eliminate the issue? Normally I'd just use a different inductor value for the woofer, but the inductor is part of the dish where the fuse, speaker terminals and other crossover components are and I'd have to add an inductor which would require mounting it somewhere in the cabinet.
What I should do is disconnect a midrange and test it using my DATS V3 speaker tester so I can see what the impedance of it is as in order for the 14uF cap value to be correct the midrange impedance would have to be 12.5 ohms provided the specs I found are correct. That's not exactly possible though given the speakers are at work now.
Specs of the speaker.
https://audio-database.com/ADVENT/speaker/a-1012.html
Also I will run these with a powered sub.
The response is +/- 3dB 42-23kHz
I currently have the powered sub crossover set to 40Hz, but am not that happy with it.
I can put two 160uF electrolytic caps in parallel to make a 320uF cap which based on the rated 6 ohms impedance of the speaker will give me a high pass of 82Hz.
I might try that tomorrow with the caps between the + speaker lead and + speaker terminal. If it sounds better then I may install the caps between the + speaker lead and woofer inductor (when i install the film caps) so that I don't run the risk of the caps affecting the midrange and treble.
EDIT:
Here's the crossover schematic I found.
However the response graph I found seems to suggest there is no hole in the frequency response.
I already ordered new caps for the crossover.
Two things I've noticed.
1. The speaker wire terminals on both speakers has separated from the terminal cup with the crossover on it at the bottom. What should I use to secure it back down?
2. I've read where the woofer doesn't play high enough causing a hole in the frequency response near the crossover point of the woofer and midrange which is 900Hz. Listening to them, I believe I actually hear that, but will wait until the film caps come in and are installed to see if that fixes it. If I still hear the issue, what is the best way to eliminate the issue? Normally I'd just use a different inductor value for the woofer, but the inductor is part of the dish where the fuse, speaker terminals and other crossover components are and I'd have to add an inductor which would require mounting it somewhere in the cabinet.
What I should do is disconnect a midrange and test it using my DATS V3 speaker tester so I can see what the impedance of it is as in order for the 14uF cap value to be correct the midrange impedance would have to be 12.5 ohms provided the specs I found are correct. That's not exactly possible though given the speakers are at work now.
Specs of the speaker.
https://audio-database.com/ADVENT/speaker/a-1012.html
Also I will run these with a powered sub.
The response is +/- 3dB 42-23kHz
I currently have the powered sub crossover set to 40Hz, but am not that happy with it.
I can put two 160uF electrolytic caps in parallel to make a 320uF cap which based on the rated 6 ohms impedance of the speaker will give me a high pass of 82Hz.
I might try that tomorrow with the caps between the + speaker lead and + speaker terminal. If it sounds better then I may install the caps between the + speaker lead and woofer inductor (when i install the film caps) so that I don't run the risk of the caps affecting the midrange and treble.
EDIT:
Here's the crossover schematic I found.
However the response graph I found seems to suggest there is no hole in the frequency response.
Another realization of Bob Cordell's THD Analyzer
- By giulianodes
- Equipment & Tools
- 234 Replies
Attachments
Directivity study- polar maps of HF, MF and LF drivers in cabinets
I've posted a small study comparing High, Medium and Low Frequency drivers in a variety of cabinets.
It's on another forum that allows me to edit/amend as more data becomes available.
First up, some pretty colors:
Edit: Feb 2025- Speaker colours explained;
SPEAKER 3...
Normalised:
SPEAKER 3:
3 way speaker with twin 12” woofers in 13.75" wide, MT cabinet 9.5" wide with 6” midrange + 1” ring radiator offset from centre, no roundovers,
2.83V input applied:
Reference:
SPEAKER 2:
Normalised:
SPEAKER 2:
3-way speaker with 8” woofer in 21cm wide cabinet with 1" roundover, and 5”/1” coaxial driver,
2.83V input applied.
Reference:
Now, if you're not sure of how what these colors/shapes mean, then this directivity study is for you!
It's aimed at bringing you along the journey of speaker designs which have with smooth frequency responses in many directions.
If you are familiar with seeing a single on-axis (or a few off-axis ) measurements for loudspeakers, please have a look at this study to observe how off-axis measurements varying over a larger span eg. up to 360° horizontally and vertically may add value to your designs, and how the use of non-normalized polar maps may assist.
My study incorporates-
1.High Frequency devices includes dome tweeters, ring radiators, ribbon tweeters, compression drivers, in cabinets with and without round-overs, with or without waveguides/horns, or even without cabinets (nude).
Start at the top for a background/explanation
Jump straight to posts for non-normalised polar maps (horizontal 0 to +/- 90 ° minimum; 0 to +/- 180 ° horizontally and vertically where/when available):
All drivers highlighted in bold type are by fellow DIYers who kindly offered their data for our perusal / interpretation.
A model of a theoretical 3/4" flat piston tweeter on a 5 1/8" wide baffle with large 1.5" round-over
SB Acoustics SB19ST-C00-04 a 3/4" soft dome tweeter on a 5 1/8" wide baffle with 1" round-over
SB Acoustics SB29SDAC on a 8" wide baffle (coming soon)
Scan-Speak D2604/8330-00: 1" soft dome on a 8.5" wide cabinet, offset 1/2" from center line
Scan-Speak R2604/8330-00: 1" ring radiator in same cabinet, again offset 1/2" from center line
Fountek NeoCD3.0 a 8x60mm ribbon tweeter on a 8.75" wide cabinet with 10mm round-over courtesy @DcibeL
Fountek NeoCD3.0 on a 11.5" wide cabinet with 3/4" round-over courtesy Curt Campbell and @jholtz
Fountek NeoCD3.5H a ribbon tweeter & integrated horn on a 8.5" wide cabinet with 3/4" round-over, courtesy Göran @gornir
Fountek NeoCD3.5H nude (not mounted on any cabinet), courtesy @Juhazi
B&W HF00963 in tapered tube hard dome tweeter in a minimal baffle/tapered cylinder, courtesy @PKAudio
Tymphany DFM-2535R00-08 attached to a SB Acoustics H225 and H250 constant directivity horns, both nude
Tweeter of SICA 5-5-C-15-CP coaxial driver, mounted in 7" circular frame with 1/2" round-over, courtesy @vineethkumar01
Tweeter for SB Acoustics SB17CAC / SB17NBAC coaxial prototype courtesy @5th element
Tymphany XT25BG60-04 in Visaton WG148R waveguide, mounted on 11" wide baffle with 1.5" round-over
Various tweeters in courtesy @augerpro's waveguides mounted in real cabinets, with or without round-overs (including SB26CDC in 6.5" elliptical waveguide, Peerless OT19NC00-04 in 8" elliptical waveguide, horizontal measurements), Donate!
SB Acoustics SB26ADC in a customized 8" waveguide for 60° beamwidth from 1K to 12KHz. courtesy @fluid
tweeter from KEF R series (non-META) coaxial, mounted in a cabinet with 1.5" round-overs
tweeter from KEF Blade Meta/Reference Meta, mounted in cabinet with 1.5" round-overs vs no round-over (awaiting cabinets)
2. Medium Frequency devices includes cones and domes, typically covering 3-400Hz to 3-4KHz
B&W 5" FST midrange in 8.75" wide cabinet with r10mm round-over, courtesy @DcibeL
Larger 6" FST midrange in 9.5" wide cabinet and 8.5" spheroidal cabinet
previous generation (Kevlar) 6" FST midrange in the same 8.5" spherical cabinet
Volt VM752 3" dome midrange in 14.5" wide cabinet, offset 1 11/16" from center, courtesy @mbrennwa
Faital 4FE42 4" cone midrange in a 6" spheroidal cabinet
Purifi 5" and 6.5" drivers on same width baffle (completed, awaiting publication)
Purifi 6.5" aluminium vs fibre cone
3. Low Frequency devices includes woofers and/or subwoofers, typically covering 3-400Hz and below:
KEF LS60 's dual 5.25" woofers, side firing, in dual opposed configuration, rear ported courtesy @bikinpunk
KEF Blade 2 Meta's quad 6.5" woofers, in dual opposed configuration, 2 on each side panel, with rear firing ports courtesy @bikinpunk
KEF R11 Meta, quad 6.5" woofers, all 4 on front panel, with rear firing ports courtesy www.audiosciencereview.com
Thanks again to all those involved who kindly supplied their measurements.
If you find anything that you feel is a misrepresentation of your data, please let me know.
All constructive comments welcome, as well as suggestions for better readability. It's a lot of graphs, I know.
PS. If a link is currently unavailable; then it is currently being updated/edited. Try again in 24 hours. Thanks for your patience.
Speaker 1...
It's on another forum that allows me to edit/amend as more data becomes available.
First up, some pretty colors:
Edit: Feb 2025- Speaker colours explained;
SPEAKER 3...
Normalised:
SPEAKER 3:
3 way speaker with twin 12” woofers in 13.75" wide, MT cabinet 9.5" wide with 6” midrange + 1” ring radiator offset from centre, no roundovers,
2.83V input applied:
Reference:
SPEAKER 2:
Normalised:
SPEAKER 2:
3-way speaker with 8” woofer in 21cm wide cabinet with 1" roundover, and 5”/1” coaxial driver,
2.83V input applied.
Reference:
Now, if you're not sure of how what these colors/shapes mean, then this directivity study is for you!
It's aimed at bringing you along the journey of speaker designs which have with smooth frequency responses in many directions.
If you are familiar with seeing a single on-axis (or a few off-axis ) measurements for loudspeakers, please have a look at this study to observe how off-axis measurements varying over a larger span eg. up to 360° horizontally and vertically may add value to your designs, and how the use of non-normalized polar maps may assist.
My study incorporates-
1.High Frequency devices includes dome tweeters, ring radiators, ribbon tweeters, compression drivers, in cabinets with and without round-overs, with or without waveguides/horns, or even without cabinets (nude).
Start at the top for a background/explanation
Jump straight to posts for non-normalised polar maps (horizontal 0 to +/- 90 ° minimum; 0 to +/- 180 ° horizontally and vertically where/when available):
All drivers highlighted in bold type are by fellow DIYers who kindly offered their data for our perusal / interpretation.
A model of a theoretical 3/4" flat piston tweeter on a 5 1/8" wide baffle with large 1.5" round-over
SB Acoustics SB19ST-C00-04 a 3/4" soft dome tweeter on a 5 1/8" wide baffle with 1" round-over
SB Acoustics SB29SDAC on a 8" wide baffle (coming soon)
Scan-Speak D2604/8330-00: 1" soft dome on a 8.5" wide cabinet, offset 1/2" from center line
Scan-Speak R2604/8330-00: 1" ring radiator in same cabinet, again offset 1/2" from center line
Fountek NeoCD3.0 a 8x60mm ribbon tweeter on a 8.75" wide cabinet with 10mm round-over courtesy @DcibeL
Fountek NeoCD3.0 on a 11.5" wide cabinet with 3/4" round-over courtesy Curt Campbell and @jholtz
Fountek NeoCD3.5H a ribbon tweeter & integrated horn on a 8.5" wide cabinet with 3/4" round-over, courtesy Göran @gornir
Fountek NeoCD3.5H nude (not mounted on any cabinet), courtesy @Juhazi
B&W HF00963 in tapered tube hard dome tweeter in a minimal baffle/tapered cylinder, courtesy @PKAudio
Tymphany DFM-2535R00-08 attached to a SB Acoustics H225 and H250 constant directivity horns, both nude
Tweeter of SICA 5-5-C-15-CP coaxial driver, mounted in 7" circular frame with 1/2" round-over, courtesy @vineethkumar01
Tweeter for SB Acoustics SB17CAC / SB17NBAC coaxial prototype courtesy @5th element
Tymphany XT25BG60-04 in Visaton WG148R waveguide, mounted on 11" wide baffle with 1.5" round-over
Various tweeters in courtesy @augerpro's waveguides mounted in real cabinets, with or without round-overs (including SB26CDC in 6.5" elliptical waveguide, Peerless OT19NC00-04 in 8" elliptical waveguide, horizontal measurements), Donate!
SB Acoustics SB26ADC in a customized 8" waveguide for 60° beamwidth from 1K to 12KHz. courtesy @fluid
tweeter from KEF R series (non-META) coaxial, mounted in a cabinet with 1.5" round-overs
tweeter from KEF Blade Meta/Reference Meta, mounted in cabinet with 1.5" round-overs vs no round-over (awaiting cabinets)
2. Medium Frequency devices includes cones and domes, typically covering 3-400Hz to 3-4KHz
B&W 5" FST midrange in 8.75" wide cabinet with r10mm round-over, courtesy @DcibeL
Larger 6" FST midrange in 9.5" wide cabinet and 8.5" spheroidal cabinet
previous generation (Kevlar) 6" FST midrange in the same 8.5" spherical cabinet
Volt VM752 3" dome midrange in 14.5" wide cabinet, offset 1 11/16" from center, courtesy @mbrennwa
Faital 4FE42 4" cone midrange in a 6" spheroidal cabinet
Purifi 5" and 6.5" drivers on same width baffle (completed, awaiting publication)
Purifi 6.5" aluminium vs fibre cone
3. Low Frequency devices includes woofers and/or subwoofers, typically covering 3-400Hz and below:
KEF LS60 's dual 5.25" woofers, side firing, in dual opposed configuration, rear ported courtesy @bikinpunk
KEF Blade 2 Meta's quad 6.5" woofers, in dual opposed configuration, 2 on each side panel, with rear firing ports courtesy @bikinpunk
KEF R11 Meta, quad 6.5" woofers, all 4 on front panel, with rear firing ports courtesy www.audiosciencereview.com
Thanks again to all those involved who kindly supplied their measurements.
If you find anything that you feel is a misrepresentation of your data, please let me know.
All constructive comments welcome, as well as suggestions for better readability. It's a lot of graphs, I know.
PS. If a link is currently unavailable; then it is currently being updated/edited. Try again in 24 hours. Thanks for your patience.
Speaker 1...
A Cheap thermal IR camera for troubleshooting power amplifiers
- By Mark'51
- Equipment & Tools
- 6 Replies
I've been working on an old power amplifier (SAE MK3CM) that has a problem with one channel. It works OK for a short time and then the positive side of the output waveform starts to clip, somewhere around 5V. Most of the voltages measure reasonably close to what the SM says they should, but one clue is my nose. I can smell something getting hot. So I decided to make myself a thermal IR camera to determine what's getting hot w/o burning myself or potentially connecting my body to up to 150V (the supply rails are +/- 75V).
I found a relatively inexpensive IR camera that has a 32 x 24 pixel array, the MLX90640. Sparkfun and Adafruit will sell you a board with one on it for about $70 -- and that doesn't include the display and Arduino-ish board needed to process and display the thermal image. However, I already had a Teensy 4.0 and a 320 x 240 TFT display so I just bought the camera chip from Digikey. The camera only has 4 pins -- Vcc, ground, SDA and SCL -- so I just soldered it down to a piece of perfboard.
Adafruit has some example programs for their version so I downloaded them and modified one for my particular display (it has about 4X the number of pixels than the one they use). And it works surprisingly well. So I cobbled together a setup to view the component side of my power amplifier and did find significant differences between the two channels. So here are a few photos showing my admittedly crude setup:
The above photo shows the display. The camera is attached to the tripod using a "C" clamp with some scrap 3D printing failure I had lying around. The amp is shown in the lower right side.
Above you can see the Teensy 4.0 and a better shot of the camera. The camera chip actually is on the bottom side of the board, because I installed it upside-down....oops...
The above image shows what the "good" side of the amp looks like, thermally speaking. The two hot spots are two cascode-connected transistors whose inputs are the front-end LTP's. In normal operation they should dissipate about 76mW.
This is a photo showing the faulty channel. At least one of the transistors -- which happens to be associated with the positive side of the output waveform -- clearly is running hotter. So I have narrowed-down my search by quite a bit. BTW, my hand, which is around 80F, only generates a yellow color so the hot spot is pretty warm.
One initially-challenging problem was figuring out just exactly WHERE those hot spots are. I tried using my finger to point at the hot spot but it was just too big. So I made a hot spot "wand". Just a 120 ohm 1/4 watt resistor taped onto the end of a wood dowel. I adjusted the power supply driving it so it doesn't overload the camera. And here's my high-tech "hot spot":
I found a relatively inexpensive IR camera that has a 32 x 24 pixel array, the MLX90640. Sparkfun and Adafruit will sell you a board with one on it for about $70 -- and that doesn't include the display and Arduino-ish board needed to process and display the thermal image. However, I already had a Teensy 4.0 and a 320 x 240 TFT display so I just bought the camera chip from Digikey. The camera only has 4 pins -- Vcc, ground, SDA and SCL -- so I just soldered it down to a piece of perfboard.
Adafruit has some example programs for their version so I downloaded them and modified one for my particular display (it has about 4X the number of pixels than the one they use). And it works surprisingly well. So I cobbled together a setup to view the component side of my power amplifier and did find significant differences between the two channels. So here are a few photos showing my admittedly crude setup:
The above photo shows the display. The camera is attached to the tripod using a "C" clamp with some scrap 3D printing failure I had lying around. The amp is shown in the lower right side.
Above you can see the Teensy 4.0 and a better shot of the camera. The camera chip actually is on the bottom side of the board, because I installed it upside-down....oops...
The above image shows what the "good" side of the amp looks like, thermally speaking. The two hot spots are two cascode-connected transistors whose inputs are the front-end LTP's. In normal operation they should dissipate about 76mW.
This is a photo showing the faulty channel. At least one of the transistors -- which happens to be associated with the positive side of the output waveform -- clearly is running hotter. So I have narrowed-down my search by quite a bit. BTW, my hand, which is around 80F, only generates a yellow color so the hot spot is pretty warm.
One initially-challenging problem was figuring out just exactly WHERE those hot spots are. I tried using my finger to point at the hot spot but it was just too big. So I made a hot spot "wand". Just a 120 ohm 1/4 watt resistor taped onto the end of a wood dowel. I adjusted the power supply driving it so it doesn't overload the camera. And here's my high-tech "hot spot":
What happen to LC Audio Technology? Acquisition by an other Company?
- Solid State
- 4 Replies
Attachments
Adding a second woofer to the speaker system
I've successfully created three-way bookshelf speakers containing a 10" woofer, a 2" dome midrange, and a 1" tweeter per closed enclosure for years. The crossovers are tuned to have output response (nearly) summing flat as shown in this picture.
However, I've been using them with an active subwoofer. Now I plan to stop using subwoofer and would like to listen to low-frequency from the main speakers. I removed subwoofer and found the bass wasn't enough, though I reckon these speakers sound flat.
I still have a pair of the woofers unused so I thought to add them to the system. In other words, the bookshelf speakers will be converted to floor-standing from now on.
The problem is I cannot easily add them without mod the crossovers. And I want to increase only low-frequency region. I finally need to convert them to 3.5-way system. In fact, I tried building them 3-way by typical way of adding the second woofer and redo the whole crossovers and found the unsatisfied result when there's no upgrading in bass SPL increasing anymore. Thus, I realized the 3.5-way system may correctly fix the problem.
Here is the simulation of the 3.5-way system that I randomly generated in simulation software.
I confess I don't have knowledge about the procedure or theory for building 3.5-way system. I simply add a second woofer with twice larger inductor on it, the 14mH coil.
And this is the comparison between 3-way and 3.5-way systems.
I would like to ask whether I did it correctly? And is the result (simulation graph) acceptable? I know the more accurate version should be from real measurement not simulation result, but this is the first step of learning. So, please try to understand.
However, I've been using them with an active subwoofer. Now I plan to stop using subwoofer and would like to listen to low-frequency from the main speakers. I removed subwoofer and found the bass wasn't enough, though I reckon these speakers sound flat.
I still have a pair of the woofers unused so I thought to add them to the system. In other words, the bookshelf speakers will be converted to floor-standing from now on.
The problem is I cannot easily add them without mod the crossovers. And I want to increase only low-frequency region. I finally need to convert them to 3.5-way system. In fact, I tried building them 3-way by typical way of adding the second woofer and redo the whole crossovers and found the unsatisfied result when there's no upgrading in bass SPL increasing anymore. Thus, I realized the 3.5-way system may correctly fix the problem.
Here is the simulation of the 3.5-way system that I randomly generated in simulation software.
I confess I don't have knowledge about the procedure or theory for building 3.5-way system. I simply add a second woofer with twice larger inductor on it, the 14mH coil.
And this is the comparison between 3-way and 3.5-way systems.
I would like to ask whether I did it correctly? And is the result (simulation graph) acceptable? I know the more accurate version should be from real measurement not simulation result, but this is the first step of learning. So, please try to understand.
Need help designing a simple flip flop for 12V trigger
- By RickRay
- Electronic Design
- 21 Replies
See the attached circuit circled in red. The circuit senses a signal and provides -12V for on and +12V for off, just the opposite of ICEPower modules. I am wanting to have the circuit provide +12V for on and 0V for off. A little more complicated than a simple flip flop. Any ideas? I can build a simple circuit on a breadboard and piggyback off the +-15V to power it.
Asathor - a JBL 4367 Clone
Hi Guys!
I have always been fascinated by the large monitor speakers from JBL. Unfortunately, these are not cheap, so I wanted to build something like the 4367 myself.
http://www.newaudio.it/JBL/4367 JBL (1)/JBL Synthesis 4367 White Paper.pdf
15 "plus compression driver / horn was given. So I started looking for suitable drivers.
My friend Nico Germanos from Quint-Audio, Germany gave me the tip to test the new Tymphany DFM drivers and sent me a pair.
Since I don't have many horns to test, I immediately sent the drivers to my DAU buddy Christian. A few days later he sent me the measurements on the Monacor MRH-200 and I was amazed. Nico was right, the Tymphany DFM-2535s run great.
Since the MRH-200 is quite expensive, I decided on the almost identical Celestion H1 9040-P, which costs only a third.
Now I had to find a suitable candidate for the bass. Since the DFM is quite cheap despite its great measurements, I wanted to stay in a similar price range in the bass as well. Together with my friends from the DAU we discussed many possible woofers, but most of the cheap ones needed too much volume for bass reflex. In the end it was the LaVoce WSF152.50, which was kindly made available to me by the German distributor Steinigke Showtechnik.
This woofer runs very well in a closed box, which is brought to a lower cut-off frequency by a high-pass cap. Not super deep, but it will work well when the speakers placed close to the walls.
Both drivers are very well made for this price range. Since the Tymphany and the horn are smaller compared to the drivers in the JBL 4367, the crossover frequency is higher than in the original. I ended up at around 1500Hz.
The box also works very well at 15, 30 and 45 degrees horizontally off-axis (2db offset).
The crossover is an 18db high pass and a 12dB low pass plus serial notch.
The cost in Europe is less than 500 Euro for a complete pair. Certainly not much for a loudspeaker that has a surprisingly good sound and can also manage very high levels without problems.
If you want to see more designs from our small diy-group, please visit our german homepage:
Presenting DIY-HiFi Projects - The Idea behind It! - Der-Akustische-Untergrund
Octal Line Stage from Vacuum Tube Valley no11 - Thoughts on Film Caps in the Power Supply?
- By dubadub
- Tubes / Valves
- 48 Replies
Greetings, Friends. I was looking at some scans of the old Vacuum Tube Valley magazine and ran across their Octal Line Stage, posted in Issue 11, Spring 1999.
I'll include the entire article at the end of the post.
It's a nice looking circuit, a cathode follower.
Looks like the 100k volume pot is acting as the grid leak resistor, don't love that. I'd add a 1M from Pin 4 to Ground.
And I guess that's a voltage doubler (?) to make 12v to allow 12S_7 tubes, don't think I'll use that. Might run the tubes on AC to start, or use a bridge rectifier with 1N5820 and CRC to make 6.3vDC.
I'd like to use some of those Vishay film caps that are so cheap now. C1 in the power supply is much too large, even with the low current demand. I'd go with 20uF, and this cap from Vishay looks very nice at $8. The 2nd cap in the power supply is spec'd at 100uF 450v, a very affordable EL cap but a rather expensive film cap. Could I use a lower-value film cap in this position without impacting the performance of the preamp?
The cap in the amp circuit is very large, 330uF 450v. The best option here from Mouser is an Audio-grade EL with a rather short lifespan. Could I use another of those 20uF film caps? As there's no film cap option for the bypass cap (330uF 35v) I'd probably use an audio-grade EL for that, and just plan to replace both caps after 2000-ish hours.
Thoughts? Thanks for taking a look!
w
I'll include the entire article at the end of the post.
It's a nice looking circuit, a cathode follower.
Looks like the 100k volume pot is acting as the grid leak resistor, don't love that. I'd add a 1M from Pin 4 to Ground.
And I guess that's a voltage doubler (?) to make 12v to allow 12S_7 tubes, don't think I'll use that. Might run the tubes on AC to start, or use a bridge rectifier with 1N5820 and CRC to make 6.3vDC.
I'd like to use some of those Vishay film caps that are so cheap now. C1 in the power supply is much too large, even with the low current demand. I'd go with 20uF, and this cap from Vishay looks very nice at $8. The 2nd cap in the power supply is spec'd at 100uF 450v, a very affordable EL cap but a rather expensive film cap. Could I use a lower-value film cap in this position without impacting the performance of the preamp?
The cap in the amp circuit is very large, 330uF 450v. The best option here from Mouser is an Audio-grade EL with a rather short lifespan. Could I use another of those 20uF film caps? As there's no film cap option for the bypass cap (330uF 35v) I'd probably use an audio-grade EL for that, and just plan to replace both caps after 2000-ish hours.
Thoughts? Thanks for taking a look!
w
J113 XEN Power Circlotron
- By woofertester
- Pass Labs
- 1 Replies
The beauty of this circuit deserves its own thread.
After considering Mr. Pass's 2025 Beast R2, I have tentatively settled on a 3-in-parallel J113 XEN Circlotron cell.
The triple cell attached idles at ~32.5mA and leaves class A at ~ 83 mA peak.
My plan is to have 6 of these triple cells driven by one cell for a total of 7 cells per "row" on a PCB.
A triple-in-parallel cell will have 6 resistors and 6 JFETs. The PCB layout should work out nicely as per the attached drawing.
6 "rows" will yield about 1A idle total for the output JFETs. The actual idle can be adjusted with the V_adj supply.
Peak current should be ~ 2.5A per the simulation. Actual peak current may vary.
Attachments
PC Companion Amplifier
Hey guys, can anyone recommend me a class D amplifier board (also in Kit) that can replace this Chinese board with TPA3116D2?
I've read almost the entire thread on the TPA3116D2 and now I know almost more than the designers
I've also read (and translated from Japanese) all the evaluations and modifications made by CyberPit that date back to 10 years ago, in the meantime I think the technology has evolved.
Unfortunately my eyesight is no longer what it was 20 years ago and I struggle to work on SMD circuits, so I'm looking for a board that sounds good with two 8 Ohm desktop speakers like the Tannoy mercury mR Cherry and a subwoofer.
I don't need excessive power, I listen to music while working on the PC, the important thing is that it doesn't require modifications (or at least few modifications) and that it sounds good.
I don't make it a question of price, but since I already have the HiFi system it must be a modest expense.
The only limitation I have is space, I bought an aluminum case with an internal space as in the photo that must contain everything: the three channels + the tone control + the power supply.
Thanks to anyone who wants to help me
I've read almost the entire thread on the TPA3116D2 and now I know almost more than the designers
I've also read (and translated from Japanese) all the evaluations and modifications made by CyberPit that date back to 10 years ago, in the meantime I think the technology has evolved.
Unfortunately my eyesight is no longer what it was 20 years ago and I struggle to work on SMD circuits, so I'm looking for a board that sounds good with two 8 Ohm desktop speakers like the Tannoy mercury mR Cherry and a subwoofer.
I don't need excessive power, I listen to music while working on the PC, the important thing is that it doesn't require modifications (or at least few modifications) and that it sounds good.
I don't make it a question of price, but since I already have the HiFi system it must be a modest expense.
The only limitation I have is space, I bought an aluminum case with an internal space as in the photo that must contain everything: the three channels + the tone control + the power supply.
Thanks to anyone who wants to help me
Latest production of D20400PLUS module
- By wyqgyn
- Vendor's Bazaar
- 20 Replies
Thank you very much Mr. Wu for providing the module. Very regret. The module is damaged. Mr. Wu kept it for 13 years, and now he has given it to me. I think I can fix him. But I'm very sorry, what he damaged was the main control chip OKI M72H035. I cannot purchase him from all over the world. I searched the whole world. No one is selling. So I made an IIS signal generator. I want to test the generation of the problem. After careful testing. Discovered that the right channel BIT17 has been at a high level for a long time. Cannot switch. I think M72H035 is completely irreparable. I want to restore the entire chip. But it's impossible. Without this main control chip, all operations are equal to 0. I used my vacation days to simulate the entire timing sequence using gate circuits. I think I can resurrect him. However, the original design had some shortcomings. Because the R-2R part uses AD7541 plus two very difficult to obtain non-standard resistance resistors. I think I can improve it. I replaced him with a more suitable chip AD7538. Now D20400 has become a true 20 bit module. It's no longer fake 20 digits. I want to share him with all friends who pursue D20400. You can purchase it now, but EU friends need to provide an IOSS number. He is composed of IM and 10 digits. Sent from Guangzhou, China. Europe needs 10 days. If you would like to obtain any information, please email: 410746700@qq.com
New never used miniDSP miniSHARC kit
SOLD
New Old Stock of discontinued miniDSP miniSHARC kit, complete, never used, opened only to take the photo. What's in that photo is what you get: miniSharc board, AC/DC power supply with multiple plugs, CD socket adapter, USB cable, coupon for software download from miniDSP
This was the core of the miniDSP OpenDRC series.
If you know what it is, you probably know how to use it. For everyone else, it's just a digital electronic doo-hickey. 😉
It was discontinued 3-4 years ago. The few retail shops that still list this item have it priced at 249€.
Asking US$180 (CA$250).
Less than what I paid, for sure... but it's not doing me any good, so make me an offer if you think my is price high.
New Old Stock of discontinued miniDSP miniSHARC kit, complete, never used, opened only to take the photo. What's in that photo is what you get: miniSharc board, AC/DC power supply with multiple plugs, CD socket adapter, USB cable, coupon for software download from miniDSP
This was the core of the miniDSP OpenDRC series.
If you know what it is, you probably know how to use it. For everyone else, it's just a digital electronic doo-hickey. 😉
It was discontinued 3-4 years ago. The few retail shops that still list this item have it priced at 249€.
Asking US$180 (CA$250).
Less than what I paid, for sure... but it's not doing me any good, so make me an offer if you think my is price high.
Hemp Acoustics/Radian Coax OB
- Multi-Way
- 2 Replies
I bought these 8" coaxial Hemp Acoustics/Radians almost two years ago and am finally taking my first measurements ever! These are indoor measurements gated at 5.2ms, 1/24th smoothing at 15° intervals. I'm on a Mac, but now wish I had a windows machine for VituixCAD and the directivity plots.
Tweeters were crossed over at 800hz. Woofers played full range.
This was a very bargain purchase and I am a total novice so I'm looking for feedback on whether these drivers are usable or not. Any other pointers are welcome.
Right Mid
Right Tweeter
Left Mid
Left Tweeter
Tweeters were crossed over at 800hz. Woofers played full range.
This was a very bargain purchase and I am a total novice so I'm looking for feedback on whether these drivers are usable or not. Any other pointers are welcome.
Right Mid
Right Tweeter
Left Mid
Left Tweeter
Compensated transmission line array
Hey folks,
Don't know if it's too weird, but I have this idea of an line array in 3 chambers wich are connected to a transmission line. I try to figure out how to simulate this in hr but I dont get it. The chassis were 9 pcs. dayton pc83-4 in an 3p3s arrangement. The 3 parallel chambers (with 3 chassis in series) should have a port to the tml at 1/4, 1/2 and 3/4. This would normally be a backloaded horn but with an offset of the connected port and on top 3 of them. I found the ME1/2 parameter but I think I need more off a ME2/3/4 instead.
Maybe someone can give me a hint.
Thx!
3emb0t
Edit:
For better understandig, the speaker should look like this:
The acoustic circuit maybe like that:
Don't know if it's too weird, but I have this idea of an line array in 3 chambers wich are connected to a transmission line. I try to figure out how to simulate this in hr but I dont get it. The chassis were 9 pcs. dayton pc83-4 in an 3p3s arrangement. The 3 parallel chambers (with 3 chassis in series) should have a port to the tml at 1/4, 1/2 and 3/4. This would normally be a backloaded horn but with an offset of the connected port and on top 3 of them. I found the ME1/2 parameter but I think I need more off a ME2/3/4 instead.
Maybe someone can give me a hint.
Thx!
3emb0t
Edit:
For better understandig, the speaker should look like this:
The acoustic circuit maybe like that:
This circuit could work?
- By Morph1214
- Electronic Design
- 7 Replies
this is a MIC preamp based on PGA2311, i would love suggestions about this design S2
For Sale LU1014D Choke Loaded Cascode amplifier
I have my last set of LU1014D amp boards which is fully built and tested. Details about the amp here - https://www.diyaudio.com/community/...d-ld1014-choke-loaded-source-follower.400792/
Built using good quality parts from either Mouser/Digikey/Newark I am expecting $165 including shipping within CONUS states.
Built using good quality parts from either Mouser/Digikey/Newark I am expecting $165 including shipping within CONUS states.
little Class A headphone amplifier thing i "designed"
- By No ideas
- Headphone Systems
- 101 Replies
feel free to leave suggestions on how to make it better and stuff
