what type of amp are you using?
Depending on the cited sources, 100 hours is nowhere near enough time to full break in any of the Fostex FE series, particularly if the net sensitivity is high and your listening habits aren't at concert levels.
Remember that any cone treatment will be irreversible, so tread carefully, but starting with a light coat or 2 of damar on the whizzer cone might be a good start. I believe DaveD and others would advise to thin down either the damar or MP and apply a succession of thin coats.
The next big leap of faith would be phase plugs - I've heard them help in a lot of ways beyond just measurable smoothing in FR performance.
And of course as Holdent just posted above, and others as well will probably advise to try BSC - depending on proximity to rear wall, this may or not be necessary.
The wider "supra baffle" approach is my personal preference - even just a couple of layers of stiff cardboard taped to the front of the box was enough for me to detect an improvement on an early build of the Ron Clark A126 and Frugel-horn prototypes.
Depending on the cited sources, 100 hours is nowhere near enough time to full break in any of the Fostex FE series, particularly if the net sensitivity is high and your listening habits aren't at concert levels.
Remember that any cone treatment will be irreversible, so tread carefully, but starting with a light coat or 2 of damar on the whizzer cone might be a good start. I believe DaveD and others would advise to thin down either the damar or MP and apply a succession of thin coats.
The next big leap of faith would be phase plugs - I've heard them help in a lot of ways beyond just measurable smoothing in FR performance.
And of course as Holdent just posted above, and others as well will probably advise to try BSC - depending on proximity to rear wall, this may or not be necessary.
The wider "supra baffle" approach is my personal preference - even just a couple of layers of stiff cardboard taped to the front of the box was enough for me to detect an improvement on an early build of the Ron Clark A126 and Frugel-horn prototypes.
chrisb said:
I have to disagree with this.
All of the 127/167/207's that I have had break in to 95% of their final sound in a very few hours. They reach a listenable condition in minutes. Even Lowther DX series are listenable in an hour or so. It may take a fair while to bring in all of the nuances at the top end, but this would take direct A/B testing with a well used driver.
Bottom end break in is 95% complete with one full cycle to Xsus. Running drivers hard for a long period of time does nothing to break it in. The way a lot of folks test new drivers is to take T/S parameters fresh out of the box, run them hard for X hours, then take T/S parameters again. They have changed. Then, sometime later, they take T/S parameters again and they change again back in the direction of the original readings. Well, yea, that happens. BTW, it really is good practice to run your driver at the power level you intend to use it at for a while, then take your readings immediately. Now your T/S parameters reflect how the driver will be used.
High end break in is primarily a matter of training your ears. The more different the sound of your new speakers from what they replace, the longer it will take for you to get used to the new sound. If you "forget" to use a proper contour (BSC) filter and do something about a rising frequency response, it will take a long, long time for the speakers to "break in".
How dare I say this? I build a fair number of speakers commercially. I build the cabinets, take new drivers out of the factory boxes and slap them in. I then let them play with normal (for me!) music for the few hours that it takes me to build up the shipping cartons and filler. The speakers now sound just the same as the speakers in my listening room that have thousands of hours on them.
YMMV, but....
Bob
I have had the exact same experiences as Bob describes above with my Fostex and Lowther speakers. If there are any changes in a driver's sound they should be extremely subtle in the high end over long periods of time. The bass output has not changed over time in my drivers, I confirmed this with both listening and T/S parameter measurements.
This is what I use with all of my FE167E speakers with a 10 1/2" baffle width:
Bob
An externally hosted image should be here but it was not working when we last tested it.
Bob
planet10 said:
Dave,
You cut the quote off a line early. I said:
" All of the 127/167/207's that I have had break in to 95% of their final sound in a very few hours. They reach a listenable condition in minutes. Even Lowther DX series are listenable in an hour or so. It may take a fair while to bring in all of the nuances at the top end, but this would take direct A/B testing with a well used driver."
You are A/B testing, and I agree that it takes a while for all of the nuances at the top to appear. But this is not the gist of the original post. He has a shouty 167E, and that part of the spectrum breaks in almost immediately. The shout in this and virtually all other 6-8" full-rangers is due to a lack of proper BSC and the 2K Hz hump. The 167E does not have a rising FR, so there is not need to treat that. Note: I put the knee of the BSC filter a bit higher than most to smooth out the leading edge of the 2K Hz hump. This is one reason that my Lowther speakers don't shout.
My show amp is a 6BX7 pp, my shop amp is a "Just the caps" SI T-amp and my entertainment center is driven by a Yamaha HTR-5240.
Bob
I have FE164 and it was shouty. Lowthers are also shouty. In my opinion the main reason is weezer cone that causes reflectons and resonances starting from upper midrange up.
I moddified the driver by cutting off weezer cone and installing phase plug (otherwise there is cone reflection caused suck-out in upper midrange). I also glued some thin felt on the basket's inside metal surfaces.
With this modification the driver looses upper highs (one can add super tweeter), but is much more listenable.
Here is quasi-anechoic freq resp. of modified FE164 in small onken enclosure (disregard response bellow 200Hz because of measurement conditions) . It sounds nice.
I moddified the driver by cutting off weezer cone and installing phase plug (otherwise there is cone reflection caused suck-out in upper midrange). I also glued some thin felt on the basket's inside metal surfaces.
With this modification the driver looses upper highs (one can add super tweeter), but is much more listenable.
Here is quasi-anechoic freq resp. of modified FE164 in small onken enclosure (disregard response bellow 200Hz because of measurement conditions) . It sounds nice.
Attachments
Well, I don't think so. Here's my FR response with nothing but a 1.5||6ohm BSC filter. This is a stock FE167E without -- no phase plug
An externally hosted image should be here but it was not working when we last tested it.
Bob, what exactly is it you "don't think so"?
I'm not sure that DIY measurement techniques are an absolute science yet, so the accuracy or relevance of either set of graphs could possibly be "questioned". (well, not by me
)
Moderate to extreme driver modification is certainly prone to self fulfilling (some have argued deceiving) improvement phenomena.
(the emperor's new cones? )
Vuki's system might very well "sound nice" to him - that's hard to quantify with any existing technology, and churlish of any of us to dispute.
I'm not sure that DIY measurement techniques are an absolute science yet, so the accuracy or relevance of either set of graphs could possibly be "questioned". (well, not by me
) Moderate to extreme driver modification is certainly prone to self fulfilling (some have argued deceiving) improvement phenomena.
(the emperor's new cones? )
Vuki's system might very well "sound nice" to him - that's hard to quantify with any existing technology, and churlish of any of us to dispute.
chrisb said:
I don't think that a "shouty" speaker is due to whizzer/main cone interference. The frequencies involved are too high up to cause shout, sibilance maybe, but not shout. Shout is caused by 1) lack of proper BSC and/or 2) a strong 2K Hz hump, which many full-range drivers, Lowther in particular, have and needs to be addressed. In the case of the FE164/FE167E, I suspect the former. If you compare my FR plot with Vuki's, you will see that all he has really accomplished is to kill the top end of his driver.
chrisb said:I'm not sure that DIY measurement techniques are an absolute science yet, so the accuracy or relevance of either set of graphs could possibly be "questioned". (well, not by me
Well, of course you can question any measurement. On top of that, the two graphs in question were taken in very different conditions. Vuki's is (probably) and indoor measurement and heavily gated. Mine is outdoor and ungated, hence the strong floor bounce. Smoothing was unspecified. Mine was 1/6 octave and I would guess that Vuki's is either 1/6 octave or 1/12 octave. His was LMS, mine was SoundEasy.Both are real MLS measureing systems, and it is pretty hared to screw up a simple on axis frequency measurement.
chrisb said:
And so is anything else done in audio. "My new speakers are the best I have ever heard!" "My new interconnects are astonishing!" "Insert your own quote."
chrisb said:
Bob
Bob Brines said:
I don't see any 2kHz hump on my graph. And I don't see need for BSC either. This is indoor measurement ca. 1m distance, nearest reflection 1,5m (floor). This is Clio MLS measurement with no smoothing.
IMO, whatever one does to that kind of driver it will never be serious speaker. It has some charm but is far away from allround good speaker.
That was my point. You problem must be elsewhere. BTW, This is the MODIFIED driver, isn't it? Is it still shouty? Your FR plot is not significantly different from mine, and mine is not shouty.
Your plot is gated too high to clearly demonstrate whether you have solved the baffle step or not. Your speaker SHOULD need some unless it is up against a wall.
Sorry, I don't know what I was thinking. Is says CLIO right on the graph. But my statement about measurements holds. It is hard to screw up an FR measurement with a MLS system
IMO, whatever one does to that kind of driver it will never be serious speaker. It has some charm but is far away from allround good speaker.
That is not the general opinion on this forum.
Bob
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