It looks like a 2nd order electrical crossover on the tweeter. As I already said if the speakers are more than 10 years old replace the surely out-of-specs cap with an audio grade equivalent one (same value electrolytic, not poly), and be done with that.
If you want to fit new drivers in those boxes then you need to create a new crossover, and for doing that you need measurement equipment, i.e. at least a calibrated mic. From a price point of view it doesn't make any sense. If you have to buy new drivers and crossover components then you are better at building a completely new set of speakers, choosing from the many reputable kits or free designs out there. Not being affiliated in any way to the vendor, I see the X-SL kit as a great value, you just need to build the cabinets: Speaker kits, loudspeaker design services, sub-woofers and amplifiers. - X-Series kits
Ralf
If you want to fit new drivers in those boxes then you need to create a new crossover, and for doing that you need measurement equipment, i.e. at least a calibrated mic. From a price point of view it doesn't make any sense. If you have to buy new drivers and crossover components then you are better at building a completely new set of speakers, choosing from the many reputable kits or free designs out there. Not being affiliated in any way to the vendor, I see the X-SL kit as a great value, you just need to build the cabinets: Speaker kits, loudspeaker design services, sub-woofers and amplifiers. - X-Series kits
Ralf
Well, Ralf, I beg to differ.
For a handful of $ you have a Panasonic mic capsule; the rest is all freeware. The most simple of Soundcards will handle ARTA or REW. Xsim or Boxsim PCD or others will do the rest.
Forget about calibrated mics as a beginner. Even the crudest of measurements will in most cases already open the avenue to a real x/o design, that may function a major clean up for these super simple, hardly-a-crossover systems.
I would not at all be surprised if the Infinity drivers would not be bad at all, but that is only a speculation.
Come on gentleman, this is DIYaudio. Just replacing a few caps is really way below yer dignity..
Good Luck,
Eelco
For a handful of $ you have a Panasonic mic capsule; the rest is all freeware. The most simple of Soundcards will handle ARTA or REW. Xsim or Boxsim PCD or others will do the rest.
Forget about calibrated mics as a beginner. Even the crudest of measurements will in most cases already open the avenue to a real x/o design, that may function a major clean up for these super simple, hardly-a-crossover systems.
I would not at all be surprised if the Infinity drivers would not be bad at all, but that is only a speculation.
Come on gentleman, this is DIYaudio. Just replacing a few caps is really way below yer dignity..
Good Luck,
Eelco
Eelco, everyone has an opinion, mine is backed up from personal experience.
I started with a panasonic mic capsule, only to find that I needed also mic preamp and a reasonable sound card. I bought a Behringer external sound card for less than 30€, and built a DIY mic preamp etching on my own the plate, drilling all the holes and soldering all the components. I use Arta (free), XSim (free) and the various PCD, FRC, BDS etc. stuff (free only if you also have excel). Building a mic out of a mic capsule was not trivial, think for example only the soldering part. And you end up with something that magically provides you a FR, but you are not sure if that rise above 5KHz is real or is only the non-flat mic response, so do you need to address it in the crossover or not? And since the variance between the capsules is high, you can't add a general FR correction, the only method is to compare the result to a reference. So in the end I bought a calibrated mic and I'm happy. If I have to start again I'll just buy a calibrated mic with integrated mic preamp, those aren't too expensive anymore.
But frankly I don't think that is a good suggestion to buy a mic, learn to use it, perform the measurements for both FR and impedance, buy a bunch of spare components (resistors, caps and coils), learn about crossovers and how to use a specific tool, for a person that is not even able today to trace an easy crossover.
And moreover the real point here is, do I have to do all this for a do-it-once project with doubtful outcome? I think not, so my suggestion for simply replacing caps or just build a new set of speakers. The OP is open to buy drivers and components but not to also buy MDF because the house rule is to use what's on hand? I think that buying anything that is not defective (i.e. all apart the caps), breaks his own rule. My suggestion was sensible: simply restore the original capabilities of the current speaker, like he did with the turntable, or build a kit or a proven design. What's not of being DIY in building enclosures for the GR Research kit?
And just to add another point, what is the time needed for doing an "upgrade"? I'd just let his daughter use the speakers in the meantime and enjoy the music, build new speakers and use those when finished. Without time pressure one can play, but I don't think that this is the case.
I end here posting a link about an upgrade of a cheap commercial speaker, showing that sometimes this is possible. Please note however that the cost for the upgrade is comparable to the initial price, and that the author is not a beginner: Zaph|Audio - Dayton B652 Tests and Modifications
Ralf
I started with a panasonic mic capsule, only to find that I needed also mic preamp and a reasonable sound card. I bought a Behringer external sound card for less than 30€, and built a DIY mic preamp etching on my own the plate, drilling all the holes and soldering all the components. I use Arta (free), XSim (free) and the various PCD, FRC, BDS etc. stuff (free only if you also have excel). Building a mic out of a mic capsule was not trivial, think for example only the soldering part. And you end up with something that magically provides you a FR, but you are not sure if that rise above 5KHz is real or is only the non-flat mic response, so do you need to address it in the crossover or not? And since the variance between the capsules is high, you can't add a general FR correction, the only method is to compare the result to a reference. So in the end I bought a calibrated mic and I'm happy. If I have to start again I'll just buy a calibrated mic with integrated mic preamp, those aren't too expensive anymore.
But frankly I don't think that is a good suggestion to buy a mic, learn to use it, perform the measurements for both FR and impedance, buy a bunch of spare components (resistors, caps and coils), learn about crossovers and how to use a specific tool, for a person that is not even able today to trace an easy crossover.
And moreover the real point here is, do I have to do all this for a do-it-once project with doubtful outcome? I think not, so my suggestion for simply replacing caps or just build a new set of speakers. The OP is open to buy drivers and components but not to also buy MDF because the house rule is to use what's on hand? I think that buying anything that is not defective (i.e. all apart the caps), breaks his own rule. My suggestion was sensible: simply restore the original capabilities of the current speaker, like he did with the turntable, or build a kit or a proven design. What's not of being DIY in building enclosures for the GR Research kit?
And just to add another point, what is the time needed for doing an "upgrade"? I'd just let his daughter use the speakers in the meantime and enjoy the music, build new speakers and use those when finished. Without time pressure one can play, but I don't think that this is the case.
I end here posting a link about an upgrade of a cheap commercial speaker, showing that sometimes this is possible. Please note however that the cost for the upgrade is comparable to the initial price, and that the author is not a beginner: Zaph|Audio - Dayton B652 Tests and Modifications
Ralf
Thanks all.
I don't make the house rules, I want to live in domestic harmony.
From the analysis, the woofer is a zero order crossover. The tweeter is probably a 2nd order Butterworth. Playing around with the 2nd order Butterworth formula, I get a cap value of 4.7 with tweeter impedance 8 ohms at 3000Hz, or 6 ohms at 4000Hz.
The inductor is not directly in the signal path. For this project, I think I will upgrade the cap, and add some foam to the cabinet.
Joseph
I don't make the house rules, I want to live in domestic harmony.
From the analysis, the woofer is a zero order crossover. The tweeter is probably a 2nd order Butterworth. Playing around with the 2nd order Butterworth formula, I get a cap value of 4.7 with tweeter impedance 8 ohms at 3000Hz, or 6 ohms at 4000Hz.
The inductor is not directly in the signal path. For this project, I think I will upgrade the cap, and add some foam to the cabinet.
Joseph
The woofer exhibits a downward slope because of its nature ( high mass and large diameter ) and that is called mechanical crossover, and applyes also to the tweeter ( other that the coil melts if overloaded )
So it is "embedded" with the woofer .
A cap and a coil make a 2nd order and it is likely to be in that range ( > 3000 Hz)
Definitely this is a second-order high-pass tweeter filter and it looks like a cheap, but properly designed one. I recommend to change only the cap with a new one.
Good idea, but be careful not to overdo it. Apply max 1 inch foam to all internal surfaces, excluding the front one.
A recommendation very view, but nobody explains why .... we want to reduce harmonics eliminate unwanted resonances and placing the cushioning material (this consumes energy), and at the same time increase the volume of the box (not too much, but should be calculated before to make the cabinet by an experienced dIYer, it is assumed that the manufacturer has already echo)
Many years ago, in a DIY project - which built and still possess - JBL, the recommendation was: place damping material on all internal surfaces.
I use my SM-62 with one modification. I applied liquid silicone on the wings of foam twice since birth (you do the math of the years) to prolong its life. So far, I can not complain.
I think it's the only thing that would in those cabinets, if capacitors are not degraded (ie, the speakers sound good) leave everything well.
There is another important point, but doing (or not) borne by each:
Here there could be a much more meaningful when you modify this parameter in the case TS twofer, where there will be a slight variation of the FS only, totally inaudible in this economic bookself alteration)
The Polycell is a small dome tweeter foam!
(Something very rare, but it still works properly, has not been degraded over time) If we apply liquid silicone will extend its life, but will alter its frequency response (or CSD, it is the same at the end of the day)
I preferred to leave it. Do not touch it, yes, it could happen that disintegrates just then .....
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https://youtu.be/2kr0iPsNUDs
you may think it is not related to this thread, but you re wrong, it is, oh yes, it damm is!
you may think it is not related to this thread, but you re wrong, it is, oh yes, it damm is!
Well, well .... I must admit, I do not understand the relationship, they are San Luis and you Santa fe .....
The singer is nice hat...
The accordion plays it much better Raul Barboza .....
Ah! He had an uncle who played the violin, but he died ...
Bueno, bueno ....debo admitirlo, no entiendo la relación , ellos son de San Luis y tú de Santa fe .....
El sombrero del cantor es bonito...
El acordeón lo toca mucho mejor Raul Barboza ....
Ah ! tenía un tío que tocaba el violín, pero ya falleció ...
The singer is nice hat...
The accordion plays it much better Raul Barboza .....
Ah! He had an uncle who played the violin, but he died ...
Bueno, bueno ....debo admitirlo, no entiendo la relación , ellos son de San Luis y tú de Santa fe .....
El sombrero del cantor es bonito...
El acordeón lo toca mucho mejor Raul Barboza ....
Ah ! tenía un tío que tocaba el violín, pero ya falleció ...
Academia, maybe you do not understand coz You do not have to face the troubles our dear friend Joseph do, Your long construction thread strongly suggest that, as the song sing, in Your house "manda el pantalón"
Why electrolytic instead of polypropylene? The electrolytics produce more distortion, as documented by many (W.Jung, et al).
Academia, maybe you do not understand coz You do not have to face the troubles our dear friend Joseph do, Your long construction thread strongly suggest that, as the song sing, in Your house "manda el pantalón"
OK- I did not hear the whole song, I'll give you another chance and will listen carefully and completely..I just wanted to avoid frustration friend Joseph because if he expected major changes in favor, they may be present for the worse, despite many well-meaning advice ...
If he asks me, gladly I will examine the inside of my SM-62, I like to take pictures of dissections speakers ....
TMH, you totally nailed it. Now, jokes aside, it seems the xov config is similar to the highly praised Seas/Dynaco A26 (mechanical LP). So the OP maybe can play adding an inductor in series with the Woofer, something between 0.7 to 1mH, and, lacking any measuring tool, switch tweeter polarity and judge by ear the most preferred config...Hahaha no.
It roughly translates to the colloquialism "he wears the pants in the family".
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