Why did you not put music caps
In.
In.
HELP AFTER MY MODS, My tweeters are subdued and weak-
So I have a pair of Mirage M1 speakers, I changed the caps in the crossovers to Jantzen Superior Z (for the tweeters) and standard z for the mids and bass.
I also changed the internal cabling to Supra Classic 2.5.
First Impressions- Not burned in yet
The highs are there but really recessed in the background. Theres a song I reference and it has a steel guitar solo, I can bearly hear it through the vocals because its seems recessed so far back.
SO HERES THE QUESTION- Is that a symptom of unburned in cables and or caps, or is that just what Supra cables give you?
When I changed the internal cabling a few years back on the same model speaker, I used DH LABS t14 Silver plated cable, This had the opposite effect, it was super bright and fast, but it smoothed out and the brightness relaxed, leaving a lot of detail but not so much your ears bled.
But here its the opposite, its dull on the top end and the vocals kind of take over and blur out the top end.
I also changed the internal cabling to Supra Classic 2.5.
First Impressions- Not burned in yet
The highs are there but really recessed in the background. Theres a song I reference and it has a steel guitar solo, I can bearly hear it through the vocals because its seems recessed so far back.
SO HERES THE QUESTION- Is that a symptom of unburned in cables and or caps, or is that just what Supra cables give you?
When I changed the internal cabling a few years back on the same model speaker, I used DH LABS t14 Silver plated cable, This had the opposite effect, it was super bright and fast, but it smoothed out and the brightness relaxed, leaving a lot of detail but not so much your ears bled.
But here its the opposite, its dull on the top end and the vocals kind of take over and blur out the top end.
78 responses Add your response
Hi Ida, I sent you a link which explains all of it. Room EQ Wizard is a free speaker / room measurement software which has been enhanced to also do impedance measurements. This includes speakers, caps and coils. It has a vibrant following, and you'll need to ask their discussion groups for more answers, but here is the link to the software: https://www.roomeqwizard.com/ And in particular, here is the description of how to do impedance measurements with it: https://www.roomeqwizard.com/help/help_en-GB/html/impedancemeasurement.html But I don't actually use it, I use low-end hobbyist/pro gear instead. Still, this would be among your cheapest options. Best, E |
I'm not able to read carefully, so I may not be understanding correctly, but I think the issue is that Tim hasn't seen this problem before. :) I have, and I've gone through the modelling. This would be the third or fourth time I've seen this issue in total, and the fix is always "magic." :) What no one believes until they see it is that the problem caused by the low ESR tends to not affect the section the caps are in, but the next one up. That makes it maddening to trouble shoot. People spend all their time and effort trying to fix the HP tweeter section, but the problem is caused by the mid or woofer section (whichever is next down). In a 3-way, these impedance issues can be compounded. The issue isn't really whether you use polar or non-polar. It's the total ESR that is playing games with you. Tim is quite right that having 2 caps in series is going to double the ESR, so maybe that one could need an extra 2-4 Ohms. With a little hacking of a couple of audio cables you can make your own cap measurement jig and use Room EQ Wizard. That will be pretty accurate and cheap. Best, E |
Sean, I see that you are going to purchase a meter... The one that I posted is more of a general speaker builders tool. It doesn't offer esr ratings, but it will measure capacitors, resistors and Inductors all 3. If you aren't worried about speaker design then you can purchase a simple cap meter. Tim |
Hi Ida, I'm not advocating you keep all the old caps. Just the one's in parallel with the drivers. Those "shunt" caps. So long as you are having a good time and learning new things, have at it. What you might also enjoy, if you get Room EQ Wizard, is measuring your system impedance with the caps. Also measure the individual driver impedance (in box) Then you can use something like XSim to simulate most of it and play around with different cap ESR in simulation. This will really help you see what is going on. Best, E |
I don't think leaving the old electrolytic caps in place is the solution. First, the jantzens ( when Tara cables not used), sounds far superior than the old caps being used with the Tara cables. So if I was going to throw my hands up , I would keep the jantzens and hunt for cables that didn't give me issue's. I tried those belden 5000 cables and didn't have issues and it sounded pretty good. Also this hasn't been driving me crazy, I've learned a lot and have enjoyed the project. I'm going to buy that meter test those caps, make sure there all good, and try and buy resistors that compensate for any disparity. And if that does nothing, and I'm ready to give up, then I'll try different cables till I get the sound like I know it's supposed to be. That's the plan, but for now I've gotta move, so I'll be on a little break for a week or two |
Idahifi's experience is exactly what I've been talking about. :) In a 2nd order hp filter, this problem occurs from a combination of: - Very low DCR in the coil - Very low ESR in the caps - Too small a resistor in series with the cap - The impedance of the next stage higher in Hz. In the right combination of things, you end up with far too low an impedance in the next stage. Of course, having a monstrous amp fixes this issue, but you'd be surprised how just a little dip around 3 Ohms or less can do this. Inexperienced modders get themselves into trouble by trying to get the lowest possible coil DCR and cap ESR without understanding the entire circuit, and bam. Best for them to only replace series caps. There may be some level shifting but it is more benign. Best, E |
@imhififan ... well, again, ESR should've had the opposite effect. The old caps matter, plus his Tara Labs are solid core. Typically solid core are not as extended on top, plus those Tara labs have some sort of circuit in them... But overall, you are correct, the Tara Labs should not have made such a big difference, unless there were other problems involved. Solder joint or one of the big caps out of phase or a combination is my best guess. |
Ok, I have avoided trying to come off as a know it all. I don't want to be that way, nor known to be that way, but I'm going into teaching mode....We are combining some difficult theories with some very elementary basics. I'm going to speak only as thought this is a tweeter. You have a 6 ohm tweeter and it is too sensitive to match your mid range or 2 way woofer, The way that most designers handle this is to add an Lpad to match sensitivities, then properly build a crossover for your 6 ohm tweeter to the woofer or mid. Another way to do it if conditions are right is to add a 2 ohm resistor... The resistor adds a pad to the tweeter, effectively turning it down and also add resistance so that you can now use an 8 ohm crossover. So 2 birds are killed with one stone. In this scenario, extra resistances reduced the tweeter output and raised its impedance. So now, ESR. l When I build a crossover, I do compensate for ESR, but it is more for exact matching crossover points than the bit of gain difference, even so, I try to match gain correctly also. So, when Sean replaced the Electrolytics or any of his current caps, the replacement caps had lower ESR resistance... The argument being made is that the reason his output is diminished is that the resistance is so far off that it is reducing the output of the tweeter. Ok, to start with, the resistance on his new caps are much lower, what that means is that there is less of a pad, adding resistance will be helping to reduce the output back to the level of the original caps.... Next, we discussed the crossover point being changed, if that happened with the exact same value of caps, his crossover point would be effectively lowered meaning... So, lower crossover point means more perceived output, less resistance means more output. Significantly lowering ESR in theory would make his tweeters louder. I hope this all makes sense. Tim |
Idahifi, Unless otherwise specified, electrolytics are polar, but crossover caps must all be bi-polar (same as non-polar). :) You can "cheat" by putting polar caps back-to-back, turning 2 polar into effectively a single non-polar with half the effective capacitance. Film caps as far as i know are all bi-polar. The rare exception to this is with battery biased crossovers. Very very rare. :) Best, E |
Another way to go is with bi-polar electrolytics. All caps in parallel add, but in series they divide. Using 2 x 2,200 uF caps in series is the equivalent of a single 1,100uF. I couldn't find a single bi-polar electrolytic at Parts Express, so I suggest a pair of these: https://www.parts-express.com/cat/non-polarized-electrolytic-capacitors/1385?N=19844+4294967118+4294... plus one of these: https://www.parts-express.com/cat/non-polarized-electrolytic-capacitors/1385?N=19844+4294967118+4294... Put them in parallel instead of in series. Again, you’ll need to compare the final ESR of the 3 parallel caps to the original serial. I suspect you’ll end up with a much lower ESR and need to adjust. My guess is your original serial was around 2-6 Ohms of ESR. With 3 parallel, modern bi-polar caps, you'll end up with around half. Best, E |
Thanks hififan for that link. Hey Tim, so I double checked the stripe on the polarized caps against a photo I had. And it matched up correctly. I replaced it with a 35v cuz that's what was in it before. I'm fairly certain it's the tweeter that's faint. I suppose the mid-range could also be faint. If your interested go to the following link (YouTube) fast forward to 117 and listen to guitar little solo where he picks the strings. It plays until 126 and then repeats. I can hardly hear that solo, it's crazy I can hear that on any system I've had, but with this new set up it's nearly non existent. So to answer your question, I think it's the tweeter, as it sounds really faint but I suppose it could be the mid as well and I just didn't realize. |
Sean, also as I mentioned in email, the 2200 mic caps are big enough to make a difference and they are polarized, so to reiterate my email... could it be that you had polarization backwards on 1 or both caps? Again, these 2 caps have enough resistance that they could matter and they are polarized... Also being 35V electrolytic, I would much prefer to see you replace those with a higher voltage polarized electrolytic. And to ask the same questions that I asked in my emails to you.... being these are all in the mid circuit, are you sure that it is the tweeter that is the problem? I haven't seen an answer to that. |
I think what Ill do is buy a tester that can check the value of the caps as well as check the ESR and see what pops out at me.Totally agree, and this link is worth a read: http://www.diyaudio.com/forums/multi-way/282847-original-electrolytic-caps-better-than-new-upgraded-... |
Well I figured I wouldn't have gotten all right, but I took a stab at it. I don't think the tweeter is bad, cuz it sounds fine with the old caps or If the Tara cables aren't used. I know it's not a mid-range issue cuz I can clearly hear the tweeter as faint when the jantzen and Tara cables are used. Now if a cap was over heated I guess that could have occurred, but what I don't understand is which cap would have been ruined. As you pointed out, the electrolytic caps I replaced don't effect the tweeter, cuz there in the mid-range / bass circuit, yet when I replaced those caps the problem resolved it self. So the cap that would have been bad due to over heating, would have been one of the mid-range/bass driver caps I swapped with an electrolytic, but I thought those couldn't effect the tweeter. And the tweeter caps weren't changed out, but the problem resolved when the bass mid caps were swapped. Quite the quandary. |
well that is partially what I said... I said that the electrolytics that you replaced are all in the midrange and that your tweeters should be functioning correctly. Either the issue is in the midrange or you have a bad tweeter diaphragm from overheating during soldering. Next I believe that if a cap is most likely not bad, but when you had the Jantzens in that you could have had a bad solder joint.... next, I said that the only 2 caps that could have much if any ESR stray is the 2 - 2200 mic electrolytics, you said that you replaced those with the exact same value. Even those, the difference should be minimum. and no, this is not an ESR problem ... unless for some reason a cap was overheated at some point in its history any you have a bad ESR cap... of course ESR is an AC measurement and the cap ESR is far above the crossover frequency.... |
Imhififan, I only replaced three of the 3.3, and left one existing one in place. I tried the other tara cable and the issue was unchanged. I didnt think it was the cables, because although they were old they were in mint shape and I bought them from an old dealer who had them in storage, they were in flawless shape. I tried Erics theory and replaced the Jantzens in C1, C3, C4 with the old electrolytics. And as Eric suggested the issue had went away. So here I am at a crossroads as I have been emailing both Tim and Eric relating to my problem. Eric suggests getting an ESR Meter find the difference between the old caps and the new caps and correct it by changing the resistor (in series with cap) with the corrected value on the resistor. On the other hand,,,, Tim says this is not an ESR issue, he says that the ESR difference is not significant enough cause this issue, and that there must be another reason for the issue, he suggested that perhaps one of the Jantzen caps is defective or mislabeled, or perhaps a solder joint wasnt making a good connection. Im pretty sure I've reiterated what I've been told by these guys, if not, I apologize for getting it wrong. I appreciate the spirited debate and strong opinions, I especially appreciate the civility between everyone who has chimed in. So thats where Im at, the worst part is Im moving in two weeks and I was hoping to wrap this up before I moved. I think what Ill do is buy a tester that can check the value of the caps as well as check the ESR and see what pops out at me. Anyone have any better Ideas,,,, dont be shy. |
The caps I replaced were:C8=4X3.3uF=13.2uF and you replaced it with 3X3.3uF=9.9uF? These cables appear to be around 25 years old. What if a connection was broken poor inside of your cable box or if a part was going bad? Not sure that you can open this thing, but I'd take a look there... I think just for kicks I'll try the other Tara cable, I would think it would be less likely to have both cables have an issue.Any outcome? |
Sean, I've been reading trying to find why your Tara Labs might be sounding so differently... Still not sure that I ran across it, but I would rather send you down that path before going through a speaker tear down. Your cables are solid core, so they naturally will have a roll off on top. From what I've read, they decoupled the cable and added some sort of coupling cap inside of that box...Wire capacitance is well known for how it affects the high end (treble). As you turn up the wire, It changes the capacitance to increase the treble within your cable.... These cables appear to be around 25 years old. What if a connection was broken poor inside of your cable box or if a part was going bad? Not sure that you can open this thing, but I'd take a look there... Right now, You've got a lot of cooks in the kitchen, you know how to get ahold of me, so I'm going to bow out for now, Tim |
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Idahifi, no. ESR = equivalent series resistance. It is measured at specific frequencies, and may be different. Again, i don't know why you are going down this route. Experiment first, replace the caps I listed. See if this fixes things. THEN if that is the problem you'll need to get measurements. Best, E |