Either a bad speaker or more likely simply reflects the change in room. Nearfield may not mean much in a room when the wavelengths approach and exceed room dimensions. Seriously doubt it is speaker break-in.
Either a bad speaker or more likely simply reflects the change in room. Nearfield may not mean much in a room when the wavelengths approach and exceed room dimensions. Seriously doubt it is speaker break-in.
So, what is seen so often here on audioscience are discussions without any supporting data. It puzzles me why that is.
To be fair, you've provided no data yourself.
The measurements you presented as evidence were taken in a different room in a different apartment FFS. How seriously do you expect that to be taken?I actually measured not only the example above, but many more speakers. I measured it personally. In case You don't tend to trust my word, it's on You. How many here are even willing to learn to do measurements. Let alone the expense of 70$ for a qualified microphone?
Just curious.
The measurements you presented as evidence were taken in a different room in a different apartment FFS. How seriously do you expect that to be taken?
I actually measured not only the example above, but many more speakers. I measured it personally.
That's not data.A bass/mid driver sized 8", coil 2", fs nom. 78Hz, actually before break-in fs is 120Hz. After 2 hours of full excursion, happily eating up some 100Watts, though, it drops close to nominal values. After a few weeks it restored to the initial 120hz. Eventually it settled at very close to OEM's data.
Bass output increased while moving to a more leaky room twice as large as the old one? As I said, it's the other way around. Both initial and recent EQing were made with nearfield measurements with appropriate gating, so this should not be a room issue. This driver is flat through 200-1000 Hz as-is, just needs some boosting for lower frequencies. I have the data. I did also measure at 1 m distance for summed response, but that's far from flat anyhow. Eighteensound makes high quality drivers, the one in the picture is a very good midbass, neo-magnet driver. Sounds great, end-game material.Either a bad speaker or more likely simply reflects the change in room. Nearfield may not mean much in a room when the wavelengths approach and exceed room dimensions. Seriously doubt it is speaker break-in.
That's not data.
... nearfield measurements ...I have the data. I did also measure at 1 m distance for summed response, but that's far from flat anyhow. ...
Should have expected an immediate attack.Especially with P/A speakers one shouldn't dismiss the idea of a substantial break-in so easily (by just unfounded speculation). There is data in my drawer:
A bass/mid driver sized 8", coil 2", fs nom. 78Hz, actually before break-in fs is 120Hz. After 2 hours of full excursion, happily eating up some 100Watts, though, it drops close to nominal values. After a few weeks it restored to the initial 120hz. Eventually it settled at very close to OEM's data.
In general some 30% or so doesn't harm, since optimum enclosure design follows the whole parameter shift, getting to the same enclosure, virtually same response. But 50%+ really suck. In HiFi such would be inacceptable, in P/A a driver gets beaten anyway.
So, what is seen so often here on audioscience are discussions without any supporting data. It puzzles me why that is.
Damnit - sorry, no I didn't mean you. I mixed up replies.You didn't mean me, did You? I just gave some numbers for a crass example (post #1162), quite along the lines drawn by post #1160. Number #1162--a lots of discussion. Actual data seems to be very hard to generate, right? But, nothing is more practical than a good theory.
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Don, sorry. There is serious plasticity in some driver suspensions. I've seen that most prominently in the anonymous driver I mentioned above. The effect of changing resonance frequency over time--rapidly to lower fs under stress, slowly creeping back up, within weeks(!), is a matter of fact with that particular driver.Should have expected an immediate attack.
I have a $1200 measurement microphone and have performed many experiments in the past. It is much more than theory to me. What I do not have is time or will to justify everything posted to doubters refuting decades of manufacturing and other data. Just don't really care... Nor do I post my resume on every post. At some point Ripley rules -- believe it or not.
That said, I have no experience with the specific drivers cited. But room acoustics can be hard to analyze and I would not so readily (dare I say "speculatively"?) dismiss that as a cause without evidence, either.
That reference is one of the clearest and most accurate descriptions of middle ear function I've seen on-line.Other factors to consider:
- Some speakers might change during "break-in", others dont - not possible to conclude from one to every speaker in the world
- Some people might not be sensitive for changes in sound character, others might be. Even the shape of the ear has a drastic effect on sound. (Dont believe it? Push your auricles forward next time you are listening to speakers ...)
Human ear - Sound Waves, Outer & Middle Ear
Human ear - Sound Waves, Outer & Middle Ear: The outer ear directs sound waves from the external environment to the tympanic membrane. The auricle, the visible portion of the outer ear, collects sound waves and, with the concha, the cavity at the entrance to the external auditory canal, helps to...www.britannica.com
New room with 5 months difference don’t sounded convincing to me, not to say new room, in my Same room if I move the sub a few feet away it gives quite prominent change in low bass due to wall reflections, plus I don’t think there’s any room which is room mode free, unless you lived in an anechoic chamber..This is a high quality 10" PA midwoofer from Eighteensound:
View attachment 182028
I bought them last summer and set up into a 2-way DIY speaker during late-summer. I did run a few minutes of multitones from REW at considerable power and when they were installed onto the cabinet, I put couple of hours bass-heavy music through them. These are not heavy woofers, these are midranges that can play a few bass notes. Then I EQ'ed them nearfield-flat through intented passband with my FusionAmp dsp's. It took quite strong filters to get it done, but it's no big deal for a dsp-computer.
Now some 5 months later after moving to a new apartment I noticed elevated bass and my Dirac shows some wild things in the bass range. "This is odd, room-mode-free room should not boost bass, it's vice versa." I think to myself, and let Dirac do it's magic. Today I finally had the time to time-align the 2-ways with my subs and while doing that, I noticed that nearfield-woofer frequency response is wild, as in "off-the-charts-wild". I removedPK F 134.0 G 6.6 Q 1.161
and reducedLS12 F 306.4 G 8.0 Q 0.707
toG 4.6
to make it flat again. That is -10 db at 134 Hz compared to initial flat response! That's some break-in for you guys!
Back in the day all acute enthusiasts used moving coil pickups with their vinyl records. The life span of the diamond tip was rated at about 1000hrs, after which a replacement wasn't possible. The whole pickup was exchanged by the OEM, or, more often changed to the next best specimen, surely more expensive (edit: quality analog asked for 500$ up (and up and up) in todays money).It took 7 months for mine to break-in or about 400 hrs. Or it was something else that caused them to sound consistently better, who knows.