Crossover burn-in SDA 2 B TLs

RandyCroissant

Ok.. its me again I did the crossover upgrades. Sonocaps, Mills, RDO198 tweets all went well the end result first week or so they sounded great. Now they sound a little harsh to say the least the mid's seem muffled, and the highs are ringing my ears. Is this to be expected? or might there be some other problem.. I auditioned and purchased these same speakers back In 88 and loved them from that day on, so getting them to sound great again is my priority. I can work through the burn in process If that is truly what is needed. By the way they are the studio black version. If that makes a difference.

Sea

I just completed the crossover rebuild on my 2.2TL's and I am in the same place as you right now. I can tell you that when I did my 1C's the same thing. Good at first then like S$$t and then over time they gradually sounded better and better. Give them about 100 hours and they will turn around. I have 2.3TL's playing constantly on an FM station. I am not sure but the experts here say that volume does not really matter.

voltz

I put some Rdo-198's in my 10's after Dave did the TL mod on the crossovers so I could use them, and their sound evolved as they were burning in, I remember talking to Dave how the sound of the tweeters was different then I ever heard before, hard to describe, but not so unpleasant but I was going 100+ hours between burn in before I would listen to them again and I did hear them changing along the way it sure seem to me that is what was happening...mostly to the high's.

now I've not heard you SDA's and I'm sure others can explain more of what you going through then me...but it sounds a little like what I experienced with my 10's.

RandyCroissant

Thanks for the info, others have mentioned this process in other posts. I didn't think the sound of the speakers would change as much as they did quite noticeable yuk...

drumminman

How many hours do you have on them?

I've rebuilt the Xovers on three sets of Polks using the Sonicap/Mills combo, and I can tell you that from my experience burn in is real. I heard improvements on my 2.3TL's at around 50 hrs, 110 hrs, 150 hrs and 200 hrs. The most was at around 110.

You may need to give them more time.

F1nut

I see the problem. You used Sonocaps when you should have used Sonicaps.

RandyCroissant

You got meF1, my spelling went with my hearing. I have about 50 hours on them so far, I'll report the progress later down the road Thanks for the info.

F1nut

Give'em 200 hours.

jimclass

Dammit, I used SnoCaps! No wonder it sounds all chocolate-y. I'm waiting for my resistors to arrive, then burn-in time for my SDA2As

RandyCroissant

Ha... Jimclass

jimclass

Now that I have completed my refurbish I am amazed at how the high end has changed. The first thing I did was replace the tweeters, and they just sounded dull. Then I got onboard the cap/ resistor/dynamatt train. Now it is much improved, but on certain recordings the highs are harsh and fatiguing. These are remastered CDs and I suspect they went overboard on the tweaks. It varies from source to source. Records sound fine. I suspect the burn-in will help if all I am reading here is true. I am also considering getting an outboard DA converter for my NAD512 cd deck. That 80's tech is not up to modern standards. It has a digital out, so I am really curious what difference it would make. Anyone tried this? Also, very impressed with the soundstage of all the Steely Dan related stuff. And surprisingly the Bowie stuff. But disappointed with the Hendrix recordings. With all the studio tricks I expected a wide soundstage, but it is actually surprisingly narrow.

westmassguy

If everything else in the chain is up to snuff, the SDAs will reveal every flaw in the recording. Garbage in/Garbage out. Sonicaps need 200+ hours minimum burn in, and the Tweeters also.

jimclass

Maybe I should put on my Garbage CDs! See ya in 200 hours

jimclass

Tonight I experienced the same thing Randy talked about at the top of this thread. I sure hope things clear up. It even seemed like the left speaker was worse than the right. I will be patient and hopefully things will get better with more hours of play.

teekay0007

jimclass wrote: »

Tonight I experienced the same thing Randy talked about at the top of this thread. I sure hope things clear up. It even seemed like the left speaker was worse than the right. I will be patient and hopefully things will get better with more hours of play.

Hey, I thought we weren't gonna hear from you on this for about 200 hours....FROM YESTERDAY!?! Anxious much?

george daniel

Been there done that,as many of us have before,,, I don't even listen to em until two hundred hours or so. It is a roller coaster ride!

Sea

george daniel wrote: »

Been there done that,as many of us have before,,, I don't even listen to em until two hundred hours or so. It is a roller coaster ride!

I agree. George clued me in to that when I did my 1C's with Calrity caps. Mine started to sound really good around 150-200 hours. I left them playing moderately loud when I left for work each day. I have just completed a crossover rebuild of a pair of 2.3TL's with Sonic Caps. These are now beyond 150 and still sound a little strident. Be patient.

jimclass

Teekay007. You got me. I must chill.

jimclass

Just curious...when you purchased your new speakers, did they sound great for a bit and then degrade to a shadow of their former self until you played them for 200 hours? If not, why not? Were the capacitors burned in before assembly? What is the reason for having to burn in the replacement components for 200 hours, but not the original components? There must be some science behind this. Does it have to do with film capacitors vs electrolytic?

Schurkey

jimclass wrote: »

There must be some science behind this. Does it have to do with film capacitors vs electrolytic?

I think it mostly has to do with the listener's belief system. What in the capacitor changes with use to improve the sound quality, except for "forming" the dielectric; which would happen quickly upon voltage application; and of course the long-term degradation of electrolytic caps has been well-known for decades. That's the extent of capacitor changes I'm aware of other than damage due to over-voltage or extreme temperature, or physical damage from crushing or whatever.

Sea

Schurkey wrote: »

jimclass wrote: »

There must be some science behind this. Does it have to do with film capacitors vs electrolytic?

I think it mostly has to do with the listener's belief system. What in the capacitor changes with use to improve the sound quality, except for "forming" the dielectric; which would happen quickly upon voltage application; and of course the long-term degradation of electrolytic caps has been well-known for decades. That's the extent of capacitor changes I'm aware of other than damage due to over-voltage or extreme temperature, or physical damage from crushing or whatever.

With all due respect, have you rebuilt a set of crossovers? Did you experience an improvement right away? Did you find that it did or did not Improve with time. I do not understand what you mean by the listeners belief system. After investing dollars and time, I would have loved for it to have sounded great right off the bat but that was just not the reality. Even though George had warned me --- when they started sounded like $hit, I still second guessed whether I had soldered something in the wrong place.

If you have had experience that is different from this I would love to hear the details.

RandyCroissant

My 2btls now have about 150 on them since the mods and they are improving. I also switched the cables from monster to Kimber. That change made a big difference in the mid and bass region, I would recommend Kimber Kable at this point, but still doin time...

jimclass

that is not cheap cable, Randy. It had better make a difference!

Schurkey

Sea wrote: »

With all due respect, have you rebuilt a set of crossovers? Did you experience an improvement right away? Did you find that it did or did not Improve with time. I do not understand what you mean by the listeners belief system. After investing dollars and time, I would have loved for it to have sounded great right off the bat but that was just not the reality. Even though George had warned me --- when they started sounded like $hit, I still second guessed whether I had soldered something in the wrong place.

If you have had experience that is different from this I would love to hear the details.

Schurkey wrote: »

Unsurprisingly, not everyone agrees with Crites. I did not hear changes--good or bad--that I can put down to "break-in" when I replaced the caps in my 1Bs. They just sounded great, instantly, and still do.

http://www.critesspeakers.com/frequently-asked-questions.html

Q: Do components have a break-in time?

A: Some do and some don't. Capacitors would be a definite NO. Let's look at this one a bit.

You have new good quality capacitors installed in your crossovers. Capacitors have exactly two qualities that effect the sound of your music that goes through them. Those are capacitance (what we use them for) and ESR. ESR is the sum of all other qualities of a capacitor other than capacitance expressed as an Equivalent Series Resistance. ESR is a bad thing. Good caps have ESR so low it is barely measurable, on the order of a couple of hundredths of an ohm. ESR is made up of stuff like the resistance of the leads and their connections to the foil inside the capacitor or stray inductance or dielectric absorption.

So, we put our new caps in the crossovers. These new caps are right on the capacitance value the design calls for and the ESR is almost unmeasurably low. What exactly of these two qualities do you expect to change with break-in? And if either of them changed, why would you expect the sound to get better since the only way they could change is to go away from the "perfect" values they had to start with? I hope any caps you use in your crossovers are good enough that they do not change at all for many years of use.


http://www.audiokarma.org/forums/showthread.php?t=637954

Quoted from another thread, but seems to apply to the issue at hand. I added the bold around my comment regarding my experience with my 1Bs.

jimclass

barring mass hypnosis, there must be some explanation for this phenomenon. I know this is a bone of contention on the forum, but enough people claim there is a break-in period that it makes me want to think there is something to it. I swear that when I listened earlier this week after not listening for a couple of days the sound was "off", and the left speaker did not match the right in clarity and presence. So I'm trying the burn-in and not scrutinizing for a while.

RandyCroissant

Depends on what your price point is, Kimber has a long history in the cable business so based on what I could afford and the information from folks out there. I went on the search and found some 4prs bought them and gave it a shot, definitely better than what I had, made a difference. down the road I might try some 8prs, that is If the house cat doesn't catch me ha..

Faustin

I have rebuilt or had rebuilt 7 pairs of vintage Polks. I can't explain the phenomenon behind c/o break in but I have definitely heard the difference from first rebuilt to 200 to 300 hours of play time. I have had some of them side by side with the same model Polks and was initially very disappointed as to how they sounded after spending the time and money on them. I have a close friend that has been involved in the rebuild and burn in process and he has heard it as well. The most dramatic were my 12's. He came by on evening around the 200 - 250 hours of burn in time and immediately asked what I did to make things sound so much better. It was nothing except letting the caps etc burn in. Perhaps witchcraft or?

F1nut

Really....you had to post that deaf guy Crites ramblings again!?! We just went through this a week or two ago with multiple reasons why caps burn in.

westmassguy

I've rebuilt close to 100 pairs of Crossovers, and without exception, the owners either contact me or I follow up with them about burn-in. Sometimes it's gradual, sometimes dramatic, but it always occurs at some point. I've experienced it myself with my own builds.

Schurkey

F1nut wrote: »

Really....you had to post that deaf guy Crites ramblings again!?! We just went through this a week or two ago with multiple reasons why caps burn in.

I looked again at that thread. I see two "reasons", but no data. You said:

F1nut wrote: »

He also ignores the fact that the material needs to form through charging and discharging, which is not all that unlike the need to bring up a long unused piece of gear on a Variac to allow the caps to form properly. In addition, the shear number of people who report the same basic results is so overwhelming that to dismiss or dispute cap burn in is foolish at best.

I thought the dielectric formed fairly quickly; seconds or minutes rather than hundreds of hours. Am I wrong? Do un-used speakers need to be "re-burnt-in" if they've been un-powered long enough for the dielectric to "un-form"?

and there's Ken's reply

Kenneth Swauger wrote: »

He completely misses dielectric absorption, also known as "capacitor memory". Charge up a capacitor then completely short it out. In a perfect world the capacitor would remain uncharged, but that doesn't happen. There will be a "ghost" of the original charge coming from the dielectric material storing the charge. In audio this effect robs transient clarity and masks detail and "pinches" the sound, especially noticeable in instruments that produce a great deal of higher frequency overtones, such as brass and stringed instruments.
If you ever find yourself internally wincing when you're listening to certain music being played on a sound system that could be the cause.

Crites claims he IS addressing dielectric absorption; he specifically said he considers it part of the ESR. Does the ESR of a cap change during burn-in?

Beyond that, there's heaps of anecdotal evidence of cap burn-in from multiple sources, which I will freely acknowledge, but I will also acknowledge that all this anecdotal evidence comes from folks who are not testing the caps for changes to the ESL, or any other measurable attribute(s) before, during and after "burn-in" that could cause the audio to change over the course of 200 hours of "burn-in". Maybe it's not a matter of capacitor burn-in being un-measurable or un-explainable; so much as no-one has taken the time 'n' effort to do so.

drumminman

The subjective evidence, i.e. the experience of diy'ers like myself, is remarkably consistent. Cap burn in is real. I've heard it on all three sets of speakers for which I've rebuilt the Xovers.

The problem here is those who insist on explaining the phenomena through scientific measurements can't see the effect through what they're measuring. I grant that. But, clearly something is going on, and it may be that we haven't discovered w-h-a-t to measure that accounts for it.

I always go by my ears. If I can detect a change I believe it.

I rebuilt a set of Def Tech BP30's 4-5 years ago. These are nice speakers, the same as the then top of the line but without the built in powered sub. Danny Ritchie of GR Research advised me, and I replaced the caps, inductors and resistors, and did point to point wiring. Def Tech was kind enough to send me the schematics.

Upon powering up they sounded OK, but not really much different than before the rebuild. I didn't really play them that much, maybe 2-4 hours per week on average. After a couple of months I felt like the bang for the buck just wasn't there. The SQ was a little better, but not commensurate with the money and effort I threw at them.

Then one night about 15 months after finishing them, I powered up the rig and it was spectacular, a clearly heard improvement. I continued to hear this over the next several listening sessions and realized it was permanent. I thought back over what changes I had made to the system and the Xover rebuild was the only one at that point.

It took several hundred hours, but it happened. When I let Danny know my experience he wasn't surprised.

Don't get too caught up in scientific explanations if your experience tells you otherwise.