You'll find the same question, worded differently, in my first post.
@ acceler8: Hooray! First useful post! It is exactly this kind of foul play I am looking for. But applied with enough sense so that the outcome is still a driver that works like it should. Preferably before the year 2017.
It is akin to accelerated lifetime tests, in which products are tested so that a couple of weeks in the lab represents years of normal use. It is not simply a matter of mistreating the product so that it is bound to fail, because then it is not going to age and fail like it will in real life. There is science behind it, in order to make sure that the aging and wear mechanisms occur just like in normal use, only faster.
What you did sounds a lot like my proposal (post #11). You filtered out the bass, putting less stress on the spider. In my view, that would give me a bit more headroom to kick the drivers through their break-in, rather than let them crawl through it by themselves. I also have read the mechanism you describe, and like you, I can't remember where. But I read a similar story from another manufacturer, at least the "spider varnish hardens and develops cracks during break-in" part, which was used to explain the shift in T/S parameters during the first hours of use. But that was about a woofer. Thanks for reminding me!
So... Cracks in varnish... Varnish hardens over time and so it will become easier to crack it. Those who have drivers made a while ago have thus an advantage over those who have super fresh drivers with varnish that is still a bit flexible. Also, cold varnish is more brittle than varnish at room temperature. So breaking them in in an unheated room or garage or shed (as long as it is clean and dry) might contribute . I don't think that baking the drivers to accelerate the hardening before break-in is going to be a good idea though...
You got the first useful post when I told you to just use the darn things and let them break in in their own time. Unless you constantly A/B the old drivers with new, out-of-the-box drivers, you will never know the difference.
Your last post is filled with guesses and assumptions with zero scientific backing. It's like spreading stuff all over a driver's cone and hoping that it will sound better. How many drivers do you intend to sacrifice developing your procedure?
In personal correspondence with the designer of MA driver, play normal music that does not have a persistent bass line (i.e, probably not dubstep) and moderate volume for the first 100hr. Moderate volume is with excursion on a 4" driver less than 1mm. To me, that volume is louder than background, but a little less than normal listening level.
Bob
Nope, I have clearly stated the questions in my post. Instead of trying to answer the questions (either in support or against a solution), you are arguing the validity of them. We clearly have different opinions on that issue, but that is not the subject of this thread, and that's why I don't consider your reply helpful. If you think in can't be done, then please tell me why with a good argument without resorting to "because Mark said so".
That is one of the ways new ideas can take shape. They are open for argument, so why don't you sink your teeth in them?
Yes, that is the standard recommendation, and I remember that we have actually explored some mechanisms that are in support of that recommendation. But Mark and his salesman have had to deal with a few too many people doing stupid things with MA drivers, and then complaining that the MA drivers were faulty or of bad design when they broke them. So I fully understand the recommendation to err on the safe side of things.
If that is the case, I think I can safely abandon my project right now, because currently I do not like the sound my drivers produce. It does not need subtle improvements, it needs big ones (and I clearly stated the required improvements), and in the other thread, it was suggested that I can fix this by letting the drivers break in. My main gripe was that the time required for this seemed to go up and up and up as the discussion progressed. So that more or less begged for my request.
I am not afraid to occasionally break something, and I am willing to take full responsibility if I do. Of course, a safe procedure is always preferred, but I am willing to try something a bit more daring if the sound after the currently ongoing break-in has not changed to my liking. So that gives us two guinea pigs: my A7P's. It is a sad fact that any advice in such a direction should always come with a disclaimer, telling people to grow a pair and take responsibility for their own screw-ups. But that doesn't mean that we should never explore something like this.
There are people over here who do just that, and just like with break-in, almost always report positive results.
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A question… what amp are you using?
I ask becaise i changed the amp drivig the A7PeN in our MTMs. and a hint of the same issue that went away with Chris' Onkyo 7.1 receiver and my PP EL34 is back -- not to the same extent, but there. Some may be running the little 5W ACA Pass ampsinto clipping but even at lower levels there is still a hint of it.
dave
I ask becaise i changed the amp drivig the A7PeN in our MTMs. and a hint of the same issue that went away with Chris' Onkyo 7.1 receiver and my PP EL34 is back -- not to the same extent, but there. Some may be running the little 5W ACA Pass ampsinto clipping but even at lower levels there is still a hint of it.
dave
I am using different amps. For the break-in I currently use a TPA2020 based class D amplifier. Nicely efficient (so no wasted energy), but not suitable for measurement. For measurement and evaluation I use an amp I made specifically for this purpose. It has a flat frequency response, low output impedance, it doesn't add too much of its own special sauce, and (quite important), it is very stable, even when cap loaded. So that gives me headroom for mucking with the filter, without having to worry about the amp's health.
I have some other stuff lying on the shelf, but this is what I currently use. A unity coupled tube amp is in the making, but that's a very long term project. In general, I found many class D implementations (for example the IRAUDAMP7 flavors that you can buy on eBay) to have response flatness issues at the high end of the range when not properly loaded with a resistive load of the rated impedance. I have one of them too, but I will not use it for evaluation, for the stated reason, before I have sorted out an overall impedance correction. And that will be a final touch to add, when I am done with the filters. Also, a TPA3116D2 board is waiting to be tried, but... first things first.
In general, the sound I get is quite dependent on the impedance of the source which drives the A7P's (and thus the topology of BSC and padding), but I have not found any magic beyond the effect on the response that speaker impedance (dominantly Le in the frequency range in which I use the A7P) has when driven from a nonzero impedance source. But maybe the other thread is a better place to discuss this.
I have some other stuff lying on the shelf, but this is what I currently use. A unity coupled tube amp is in the making, but that's a very long term project. In general, I found many class D implementations (for example the IRAUDAMP7 flavors that you can buy on eBay) to have response flatness issues at the high end of the range when not properly loaded with a resistive load of the rated impedance. I have one of them too, but I will not use it for evaluation, for the stated reason, before I have sorted out an overall impedance correction. And that will be a final touch to add, when I am done with the filters. Also, a TPA3116D2 board is waiting to be tried, but... first things first.
In general, the sound I get is quite dependent on the impedance of the source which drives the A7P's (and thus the topology of BSC and padding), but I have not found any magic beyond the effect on the response that speaker impedance (dominantly Le in the frequency range in which I use the A7P) has when driven from a nonzero impedance source. But maybe the other thread is a better place to discuss this.
I have just done the post break-in evaluation. To my ears, very little (if anything) has changed. The same strengths and weaknesses were there with my test tracks. The measurements showed a subtle difference at the onset of the top-end resonance near 16 kHz, but I doubt that is something that can be noticed, unless a fresh pair of drivers is put up against it for immediate comparison.
IMHO, what can be learned from this exercise is that, when a driver is not to one's taste, break-in is not going to fix it. Unless the listener is being fixed, as described by posts 3 and 5. I explicitly wanted to prevent this psychological process from taking place. It is a waste of time and effort, and it doesn't last. The "stay or go" decision could have been taken quite a while ago, there was no need to postpone it until after a break-in period.
IMHO, what can be learned from this exercise is that, when a driver is not to one's taste, break-in is not going to fix it. Unless the listener is being fixed, as described by posts 3 and 5. I explicitly wanted to prevent this psychological process from taking place. It is a waste of time and effort, and it doesn't last. The "stay or go" decision could have been taken quite a while ago, there was no need to postpone it until after a break-in period.
Morning
thank you for your evaluation!
Seems that my conjecture about the recommended very long break-in period of MA drivers is affirmed by your experience.: the ear gets lots time to get used to the idiosyncrasies so after the dictated hundreds of hours it will be "happy" with break up resonances etc of the driver...
Regards
thank you for your evaluation!
Seems that my conjecture about the recommended very long break-in period of MA drivers is affirmed by your experience.: the ear gets lots time to get used to the idiosyncrasies so after the dictated hundreds of hours it will be "happy" with break up resonances etc of the driver...
Regards
I think you are right. The MA drivers (and many other boutique drivers as well) have a rather outspoken character to their sound, which may or may not be your "thing". If it is, they should simply work for you right away. If it isn't, I think it is better to admit reality and try something else than it is to batter yourself into acceptance.
I have a similar issue with SET amplifiers. They do some stuff very well, but they are no universal blessing IMO, due to their character. Rather than just enjoy the music I like, I found myself limiting myself to those kinds of music that would allow me to keep using my (expensive!) amplifier, by looking for music that wouldn't expose its shortcomings too much. It took me a while to admit that I was trying to adapt myself to my creation, rather than the other way around, and that they were just not my thing. I didn't want that to happen a second time.
I have a similar issue with SET amplifiers. They do some stuff very well, but they are no universal blessing IMO, due to their character. Rather than just enjoy the music I like, I found myself limiting myself to those kinds of music that would allow me to keep using my (expensive!) amplifier, by looking for music that wouldn't expose its shortcomings too much. It took me a while to admit that I was trying to adapt myself to my creation, rather than the other way around, and that they were just not my thing. I didn't want that to happen a second time.
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