I've read elsewhere that some drivers require a break-in period. Is this all drivers?
They were talking Lowthers full range stuff.
How about my 15" PA woofs? How about the compression tweeters?
What should I expect over the next year? [these are outdoor speakers only, not a lot of use].
They were talking 100 hours plus. I was not aware of the extent of it
Thanks,
Cal
They were talking Lowthers full range stuff.
How about my 15" PA woofs? How about the compression tweeters?
What should I expect over the next year? [these are outdoor speakers only, not a lot of use].
They were talking 100 hours plus. I was not aware of the extent of it
Thanks,
Cal
I have one direct experience that supports the idea of speaker breakin. When I first put my TAD 4001's into service they sounded compressed and lifeless. Needless to say I was very disappointed (although I got them for less then nothing. Another story.) I continued to play them in hopes they would come around. They did in about the 3rd week. Not over night, but almost. In a matter of a few days they were sounding more open and un-strained. The dynamics came last, but bests of all they never lost the smoothness.
So is breakin for real. For my subs, maybe, my mid-basses, maybe, my mid-horn compression drivers, definitely.
So is breakin for real. For my subs, maybe, my mid-basses, maybe, my mid-horn compression drivers, definitely.
For low frequency drivers I point the thing facing upward in free air and apply just enough low voltage AC from a transformer to make it hum at say 50% of Xmax, maybe a little more. I did a pair of 12" 50 watt paper cone woofers last weekend with a peak to peak displacement of about 9-10 mm. I let it run for about 2 hours.
I read a Philips app note from about 1983 that was saying that under these conditions the majority of the settling-down of the speaker parameters e.g. Fs and Vas occur in the first 30 minutes. I did one overnight once and didn't realise that one of the flexy wires had a bad mechanical resonance at 50Hz and after many hours of this treatment the connection between it and the voice coil wire became intermittent and sort of fuzzy sounding. It was a dirt-cheap speaker though.
I read a Philips app note from about 1983 that was saying that under these conditions the majority of the settling-down of the speaker parameters e.g. Fs and Vas occur in the first 30 minutes. I did one overnight once and didn't realise that one of the flexy wires had a bad mechanical resonance at 50Hz and after many hours of this treatment the connection between it and the voice coil wire became intermittent and sort of fuzzy sounding. It was a dirt-cheap speaker though.
This question comes up a lot. Many people have opinions based on aural memory (which is notoriously bad even with experienced listeners)
See this link.
http://groups.google.com/groups?hl=...break-in+dick+pierce&btnG=Google+Search&meta=
See this link.
http://groups.google.com/groups?hl=...break-in+dick+pierce&btnG=Google+Search&meta=
So what Dick Pierce says is gospel ?!
Has he ever noticed that for a reflex (the most used principle currently) tuning both VAS and fs have great influences ?
Regards
Charles
BTW: Please look at note #6 on the following data-sheet of a well-known manufacturer: http://www.jblpro.com/pages/pub/components/2206.pdf
Has he ever noticed that for a reflex (the most used principle currently) tuning both VAS and fs have great influences ?
Regards
Charles
BTW: Please look at note #6 on the following data-sheet of a well-known manufacturer: http://www.jblpro.com/pages/pub/components/2206.pdf
I have never seen or heard anything proving this statement, and my own measurements have disproven it.
Actually, if you look at Changes in Cms, which causes complementary changes in Vas iand Fs (Vas increases and Fs drops by the square root) - you often need to cause a change of 30% or so to cause a change of 1 dB in the bass.
Many people have noticed speakers character changing after a break-in period. My ears have proven it to me and others used their ears to agree. A sine wave is no test of a speakers sound reproduction capability. It does nothing to show impulse response that is critical to the 'sound' of a driver. Impulse response appears to increase with a break-in. I have no imperical data, but ears know what sounds more real. Auditory memory might not be accurate but the ears knows what sounds right, that does not change over time.Ron E said:
Here's an alternative explanation for you. Your ears get used to the sound. It takes some time to do this, but the ears do it automatically.
I have experienced this many times.
When you are used to sound as it is reproduced by a reference transducer, what you notice most early on when switching to another transducer is the differences between the two. Switch from a too-bright speaker to one that has a more neutral balance and the neutral one will sound dull..... etc...
An analogy is the difference in light quality between different types of light (incandescent, fluorescent, sodium, etc...). THe eye adjusts for this automatically after a few minutes. The film cannot adjust automatically to these differences as the eye would, so pictures taken with film balanced for daylight look yellow when the light source is sodium or incandescent, and the pictures look blue when the light source is mercury or fluorescent.
Objective measurements are like the film. It's all about perception.
I have experienced this many times.
When you are used to sound as it is reproduced by a reference transducer, what you notice most early on when switching to another transducer is the differences between the two. Switch from a too-bright speaker to one that has a more neutral balance and the neutral one will sound dull..... etc...
An analogy is the difference in light quality between different types of light (incandescent, fluorescent, sodium, etc...). THe eye adjusts for this automatically after a few minutes. The film cannot adjust automatically to these differences as the eye would, so pictures taken with film balanced for daylight look yellow when the light source is sodium or incandescent, and the pictures look blue when the light source is mercury or fluorescent.
Objective measurements are like the film. It's all about perception.
Circlotron said:
Hi,
I do the same with new speaker units (bass and mids) but use a sine generator tuned to Fs of the speaker. You will be amazed how little power is needed to get excursion to X_max. After a few hours Fs clearly drop with most speakers. It is mainly because the spider becomes more flexible. I usually run in speaker units for 48 hours at Fs and X_max this way before measuring T/S and designing them in.
It has nothing to do with fairy tales, it is just a real phenomenon.
Cheers
I think it does have an effect on our perceptions. This is why I didn't claim I heard the difference after my subs or mid-basses broke in. I made too many other changes to say it was one or the other. With the horns it was a case where I put them in the system got the level set where I wanted it and didn't change anything for a couple months. I switch the polarity once and switched it back because I was disappointed with their performance, but didn't have the time to really dig into them.eStatic said:
These compression drivers took about 3 weeks of normal (apartment at the time) listening to really come to life. The change was not subtle. Nearly everything about the performance of these drivers improved. Things like detail and upper extension improved a little, but characteristics like impact and dynamics improved dramatically.
Roddyama quotes JBL technical literature about their pro drivers...
There is an alternative interpretation to what JBL has published. As Dick Pierce states, there are temporary changes in T/S parameters associated with drive level, etc, that are recoverable. When JBL states that their T/S measurement method replicates operating conditions after a driver has been installed and operated for a short time, it is equally valid to interpret this as "operating T/S parameters", since T/S parameters change with drive level, etc... T/S parameters are linear approximations, not hard numbers
Do this: Measure the T/S parameters of a "well broken-in" driver, then run it for an hour at a normal level with music signals, then measure the T/S again. You will notice that the T/S have changed. Leave the driver sit for a few hours and measure it again. The T/S are the same as the first measurement. I have seen this effect many times.
As far as Estatic and Pjotr's comments go, read Dick Pierce's words. I am not denying the suspension compliance changes. I am denying the tonal balance changes that people claim for broken in drivers, cables, amplifiers, whatever.... There is nothing but anecdotal evidence for this. If you challenge these audio mystics' beliefs, you are mocked (even by a "so-called" moderator - I suggest you look up the term).
Skeptically yours
Ron
There is an alternative interpretation to what JBL has published. As Dick Pierce states, there are temporary changes in T/S parameters associated with drive level, etc, that are recoverable. When JBL states that their T/S measurement method replicates operating conditions after a driver has been installed and operated for a short time, it is equally valid to interpret this as "operating T/S parameters", since T/S parameters change with drive level, etc... T/S parameters are linear approximations, not hard numbers
Do this: Measure the T/S parameters of a "well broken-in" driver, then run it for an hour at a normal level with music signals, then measure the T/S again. You will notice that the T/S have changed. Leave the driver sit for a few hours and measure it again. The T/S are the same as the first measurement. I have seen this effect many times.
As far as Estatic and Pjotr's comments go, read Dick Pierce's words. I am not denying the suspension compliance changes. I am denying the tonal balance changes that people claim for broken in drivers, cables, amplifiers, whatever.... There is nothing but anecdotal evidence for this. If you challenge these audio mystics' beliefs, you are mocked (even by a "so-called" moderator - I suggest you look up the term).
Skeptically yours
Ron
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