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 think I know what happened. You removed electrolytic shunt caps without taking into account the reduced ESR.
The easiest way to fix this is to replace the original shunt caps. By shunt, I mean caps that go towards ground, and are not in series with the driver.
If you have the right measurement tools, like DATS or REW with the right jig, you can measure the original caps, and compensate for the low ESR with added resistance in series.
It is particularly difficult to find this issue for most because the problems tend to occur where you don't expect it. That is, the treble droop happens because of something you did in the midrange filter circuit.
This problem also occurs with series caps, but changes there tend to be much more subtle, it's hard to go entirely wrong. The shunt caps, having the ability to create a short to ground, are the most troublesome.
Eric thanks for your response,. So I can still hear the tweeters but I it seems like certain frequencys it sounds laid back and I can almost not even hear it. Is this consistent with what your talking about. I must admit it's a bit over my head, what your saying. I did replace tow of three of the mid-range caps, as well as three of the five tweeter caps. Would you place the mid caps back in to see if it improves?
Admittedly, I am the dude who knows just enough to get himself in trouble.
So forgive the stupid questions....
So I haven't pulled apart the other speaker's crossover yet, is there a way I can measure the resistance on the other crossover to see where it's supposed to be, so I can figure out what resistor to add in series of these new caps.
Also I'm having a hard time figuring out what new caps are going towards ground and not in series with the driver. Would anyone mind looking to see if you can determine this from the pic https://postimg.org/image/er6t30pon/
I'm at that point where I spent a good amount of time and money, and I'm left with a sick feeling of oh crap I don't like this... Please, if you can take a stab at this , I'd be forever grateful....
Hi Idahifi, The last time that I used the Jantzen Z caps as replacements, I had the exact same issue. It took about 40 hours before they came to life. If it is truly a problem of ESR differences in caps, that can be measured and compensated for with a resistor. Really the series resistance shouldn't be great enough unless there are alot of caps paralleled maybe, but if resistance is that far off, it could even effect the crossover point. Overall simple cap replacements in a crossover should not be a problem.
I find that every component has a sonic signature. Film and foil caps are the most neutral, with few exceptions. I find the most neutral of the sanely priced caps to be MIT Multicap styrene film and tin foil.
I haven't used Jantzen caps, so I can't offer specific comment, but I can tell you that every electrolytic you replace has the potential to dramatically change the sound. At first, the sound may appear to be less bright, but that is probably because electrolytics tend to introduce lots and lots of nasty high frequency distortions, which can be confused with brightness. So replacing the electrolytics is simply removing high frequency distortion.
Try some unprocessed female vocals. See which speaker sounds the most like the women in your life. Then live with the sound for a month, and try again. You may be surprised.
So this morning I was fortunate to speak with a guy from a Mirage distributor who was quite familar with the M1. He said that the ESR should not be an issue. He told me to check all the solder joints. So I did and I realized that the joint feeding the "hi" section of the cross over looked suspect I re soldered it and tried the crossover, and low and behold the upper highs have returned to at least be in acceptable parameters, and comparable to the other crossover.
Despite the tweeters sounding more normal, the sound overall still sounds a smeary, or, maybe choppy, I dont know how to explain it, its not quite smooth yet. So will the smoothness come with time? Tim did you find this with yours?
Another thing is I am wondering if I should increase the resistance due to the lower esr caps replacing the old Electrolytics. I dont want to get to far off from the traditional M1 Sound, but I am up to increase the detail and smoothness, which is why I replaced the old caps in the first place.
Thanks for posting the schematic Sean.... I can see a lot more now.... OK, so this is a series crossover, parts burn in takes about twice as long to burn in rather than a paralleled layout.... Yes, I had a similar effect on my speakers and no, I would not change any resistors. My instincts are that your ears will take some time to adjust even after these break in. The Z is a tad more laid back than most, yet a very detailed pleasing cap. I suspect once they break in fully and you become accustomed to them, you won't want anything else.
So looking at the schematic, the two caps I would be most suspect of are C3 and C4. Note they have a resistor in series with them, so the overall resistance there must be important. I would suggest you go back to the original caps there, and listen again.
If this fixes your problem, you’ll want to figure out the ESR of each one by substituting larger R3/R4 to make up the differences.
Almost missed it, C1 is the same way. My suspicion is that the resistors in series are going to be really small , like 2-5 Ohms max.
C1 is in the woofer circuit C3 & C4 are in the midrange R3 is in the midrange R4 is comp on the tweeter I'd put a signal on these and let them burn in for 100 hours or so, then listen again. If these are anything, but a nice improvement in smoothness and detail from before the mod, then there is a problem. I'd let this play for awhile, then sit down for a serious listen.
Too low impedance in the second poles _may_ lead to lowering of system impedance above the cut off. I know it’s weird, but I’ve seen it and modelled it a few times. It is a real effect.
Whether that is what the OP is suffering from I am not sure, but the series resistors are a clue. Usually those are in place to prevent a dead short. Fortunately, the proof of this hypothesis is cheap. :) Just replace the caps with their originals and listen. If that proves to be correct, then the OP knows what to fix.
Now that I see your schematic, I suspect that you might want to experiment with different caps for C7, C8, and C9.
Since Jantzen are metalized poly, you might find a considerable improvement by going to MIT film & foil caps: RTX series (styrene/tin) for values 3uF and below, or MIT PPFXS (polypropylene/tin) for values 3 < 12 uF. I use these for high end DIY, and I suspect that your M1's are worth it too.
Heard a pair once. Bloody nice speaker in standard form, if they’re working fine. Great bass definition even when driven by a 80w P/P pentode. But they need air around them, because of the rear firing tweeter. Like this.
It only happens when I use the Tara labs temporal continuum speaker cables. I can't believe I didn't catch that before..
I really love these speaker cables, there very good, but using them with this new set up, the highs sound terrible.
With using just plain old zip cord I get better highs than the temporal continuums.
Anyone have any idea why?
Next thing is what cables to replace these with, I don't want zip cord for my main speaker cables, I want something as good as the Tara's but without the weird tweeter issue.
Also , Tim not to beat a dead horse, but my bottom end is a little booty almost muddy, would this also improve with break in or is it a result of the supra cables, do you think?
Thanks for all your input, I can tell the sound is already smoother than before and more lively. Excited to hear it after a few weeks of playing it.
Hi Sean, Well since its your thread and you asked, I'll go a bit off subject and answer your question. There are some general rules about cables, that overall hold true... overall, but not entirely... Heavy gauge solid core transfers bass better, lighter stranded cables transfers high end better. Of course a lot of other things affect this.... wire coating (skin effect) purity and type of copper or coating on copper, is there a braid or only multiple individual strands...etc etc etc. Myself, My favorite cables were made of 38 gauge cotton coated litz.... Multiple stands were used in several different braids twist etc until we found the right mix.... final result was about a 9 guage cable... this was a very pleasing, yet detailed cable. In your woofers, I would probably use the heavy belden on the woofer, then make sure that you use one of the nice standed wires on your tweeter. As far as your speaker cables, I'm sorry, but I have no experience with the Tara Labs, that's why I gave a very basic elementary cable explanation, to help you discover what might make a difference in your system. Next, don't throw in the towel yet, your speakers will continue to go through minor changes for quite awhile. I hope this all helps, Tim
I'm a hififan, I tried the dials on all settings, with no change.
The caps I replaced were: the electrolytic, (2- 6.8uF , 2- 8uF, a 47uf and a 10uF) Also film caps, 3- 3.3uF, 2 -10uF and a 4.7uF. Two polarized electrolytic 2200uF, but these I replaced with electrolytics.
How can I tell what the resistance should be, that device that Tim posted , will that tell me the correct resistance? If I measure the other crossover that I haven't changed any electrolytic caps out of yet. If I find out the correct resistance can I change the resistors to the correct values. I want to keep the jantzen caps but I don't want to alter the intended resistance, can I accomplish this by swapping resistors with an higher resistance?
By the way, I completely agree with georgehifi's recommendation of pulling these out from the wall also to start. Hopefully leave them out, but if your high end doesn't return as strongly as you like, as you move them back towards a way, the higher frequencies should be what you hear reflected first, reinforcing or enhancing the high end a bit.... good luck in your journey brother, sounds like fun.
How can I tell what the resistance should be, that device that Tim
posted , will that tell me the correct resistance? If I measure the
other crossover that I haven't changed any electrolytic caps out of
yet. If I find out the correct resistance can I change the resistors to the correct values. I
want to keep the jantzen caps but I don't want to alter the intended
resistance, can I accomplish this by swapping resistors with an higher
resistance?
The device that I posted is called an LCR Meter... It reads L or Inductance.... Coils. It measures C or Capacitance.. Capacitors, it measures R or resistance.... resistors or even line resisitance. A very different device than what imahififan posted
So forgive the stupid questions, I am trying to wrap my head around all this. So Tim with the meter you listed, do you just measure the resistance between the cap leads? Is the resistance the same as the ESR.
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.
Also, tried changing the position of the speakers in relation to the wall, it made no difference on the top end, at least when using the Tara's. It's so rolled off sounding it really sounds like the pre/pro has some strange surround field that's changing the sound , but that's not the case.
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
The caps I replaced were: the electrolytic, (2- 6.8uF , 2- 8uF, a 47uf and a 10uF) Also film caps, 3- 3.3uF, 2 -10uF and a 4.7uF. Two polarized electrolytic 2200uF, but these I replaced with electrolytics.
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.
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.
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....
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.
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.
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.
You must have a verified phone number and physical address in order to post in the Audiogon Forums. Please return to Audiogon.com and complete this step. If you have any questions please contact Support.
