And I gotta say, it's sure great when a manufacturer jumps on a forum and talks about such things. Mark has sweat blood over these drivers and still comes on here and deals with this. Reminds me of when Kevin Haskins maelstrom drivers were popping. Always happens to the good guys.
Buying an MA driver is like buying a finely honed raced bike (see avatar picture), they're built to the limit. I like that. My bike revs to 17000rpm safely and makes 112 horsepower at the wheel from 600cc. With that comes a great responsibility that it's driven properly. If I rev it to 18000rpm, I'm going to receive 4 pistons into my anus as they blow out the top of the engine. Possibly like my bike, these drivers have little room for error. But within their limits the performance is hard to beat.
Buying an MA driver is like buying a finely honed raced bike (see avatar picture), they're built to the limit. I like that. My bike revs to 17000rpm safely and makes 112 horsepower at the wheel from 600cc. With that comes a great responsibility that it's driven properly. If I rev it to 18000rpm, I'm going to receive 4 pistons into my anus as they blow out the top of the engine. Possibly like my bike, these drivers have little room for error. But within their limits the performance is hard to beat.
Hi Tux,
Many thanks for your vote. its much welcomed. For me, being here on the forum is great, but I can also understand why other makers avoid forums as there's so many demands of all sorts.
I do have sympathy for those like member 5th who want absolute X max answers. But there aren't any absolutes, so pushing this notion has the potential to mislead many members who aren't completely sure about the specifics of driver operation. It increases my already bulging email in-box, where 80% of the info-help requests coming in are on other driver makes!!
I could possibly devise a specific isolation load test that takes drivers to their braking point. But what criteria do we use? Signal generation or music? If signal generation, what signal type and amplitude? If music, what music? Do we test in free air, or in box? If free air, what baffle size? If box, which box design? What loads do we apply? For how long? One continuous run or allow the driver to rest? If so, how long? What temp and humidity conditions should be applied? etc. etc etc................ Such a test might be applicable if all end-users universally agree to operate drivers to fixed load parameters, in one box type, using one type of amp at one fixed output in one size of room with a specific level of damping. A fixed test outcome will only be of practical use if the application is also fixed. So trying to calculate the safe fixed application of X isn't realistic, nor is it practically achievable. There are too many variables to make a test reliable for use in the field.
Few (if any) driver designers and makers publish a version of X Mech that specifically determines the breakdown of a driver under extreme load. Where a maker refers to X-Mech (or similar) its commonly a reference to the actual physical limit of travel of the driver's power train. Depending on the design of the power-train, typically X-Mech is around twice the length of X-max. But these physical dimensional differences can vary significantly.
I really like your bike comment. Its a good metaphor for many small(ish) and Full-Range driver makes, including mine. There are guys who push my drivers allot, more so than most other Full-Range makes so I'm confident CHR's and alike can do a decent job.
All the latest drivers main features have come about from members feedback on this forum. There's lots of posts on driver development, wish lists etc. The new Alpair 12 is gradually taking shape, so let me know by posting your desires: More SPL, dispersion and bandwidth V more power?:
http://www.diyaudio.com/forums/mark...-alpair-12-3-diy-community-development-5.html
Cheers
Mark.
Many thanks for your vote. its much welcomed. For me, being here on the forum is great, but I can also understand why other makers avoid forums as there's so many demands of all sorts.
I do have sympathy for those like member 5th who want absolute X max answers. But there aren't any absolutes, so pushing this notion has the potential to mislead many members who aren't completely sure about the specifics of driver operation. It increases my already bulging email in-box, where 80% of the info-help requests coming in are on other driver makes!!
I could possibly devise a specific isolation load test that takes drivers to their braking point. But what criteria do we use? Signal generation or music? If signal generation, what signal type and amplitude? If music, what music? Do we test in free air, or in box? If free air, what baffle size? If box, which box design? What loads do we apply? For how long? One continuous run or allow the driver to rest? If so, how long? What temp and humidity conditions should be applied? etc. etc etc................ Such a test might be applicable if all end-users universally agree to operate drivers to fixed load parameters, in one box type, using one type of amp at one fixed output in one size of room with a specific level of damping. A fixed test outcome will only be of practical use if the application is also fixed. So trying to calculate the safe fixed application of X isn't realistic, nor is it practically achievable. There are too many variables to make a test reliable for use in the field.
Few (if any) driver designers and makers publish a version of X Mech that specifically determines the breakdown of a driver under extreme load. Where a maker refers to X-Mech (or similar) its commonly a reference to the actual physical limit of travel of the driver's power train. Depending on the design of the power-train, typically X-Mech is around twice the length of X-max. But these physical dimensional differences can vary significantly.
I really like your bike comment. Its a good metaphor for many small(ish) and Full-Range driver makes, including mine. There are guys who push my drivers allot, more so than most other Full-Range makes so I'm confident CHR's and alike can do a decent job.
All the latest drivers main features have come about from members feedback on this forum. There's lots of posts on driver development, wish lists etc. The new Alpair 12 is gradually taking shape, so let me know by posting your desires: More SPL, dispersion and bandwidth V more power?:
http://www.diyaudio.com/forums/mark...-alpair-12-3-diy-community-development-5.html
Cheers
Mark.
Scanspeak and Seas consistently describe the Xmech parameter. You are correct in saying that lots of manufacturers don't, but one could argue that perhaps it isn't needed. I think most people assume that a driver can go a bit further then its rated Xmax without damage occurring. Say a +-5mm driver can easily hit +-7mm.
In the case of your drivers however it would seem like it could be somewhat necessary because the rated Xmax of the drivers don't accurately describe the physical limitations of the driver.
I think it would be rather simple to test your drivers to find out what a reasonable Xmech figure would be.
Take say a few Gen 2 Alpair 10.2s. Have them in free air or a box if you prefer, free air would be quieter though! Calculate the required RMS voltage drop required across the voice coil to provide +-1mm, +-2mm ....+-10mm etc of excursion.
Run one driver at +-1mm for 24 hours @ 40hz and see if there are any signs of damage. None? Get another driver and do the same but this time at 2mm. Keep going. If after a few days the 24 hour test @ 40hz shows signs of cone deformation at say +-5mm, then back off. Take a new driver and run it at +-4mm for 48 hours then check for damage, none? Run the same driver for another 24 hours and check again. Still no damage? Keep running the driver for say a week and if you like even go for two weeks, no damage? Then I'd say +-4mm would sound like a reasonable Xmech parameter.
In the case of your drivers however it would seem like it could be somewhat necessary because the rated Xmax of the drivers don't accurately describe the physical limitations of the driver.
I think it would be rather simple to test your drivers to find out what a reasonable Xmech figure would be.
Take say a few Gen 2 Alpair 10.2s. Have them in free air or a box if you prefer, free air would be quieter though! Calculate the required RMS voltage drop required across the voice coil to provide +-1mm, +-2mm ....+-10mm etc of excursion.
Run one driver at +-1mm for 24 hours @ 40hz and see if there are any signs of damage. None? Get another driver and do the same but this time at 2mm. Keep going. If after a few days the 24 hour test @ 40hz shows signs of cone deformation at say +-5mm, then back off. Take a new driver and run it at +-4mm for 48 hours then check for damage, none? Run the same driver for another 24 hours and check again. Still no damage? Keep running the driver for say a week and if you like even go for two weeks, no damage? Then I'd say +-4mm would sound like a reasonable Xmech parameter.
Mark,
Full range drivers by B&C, Eminence, JBL and many others all can withstand continuous use at Xmax as long as power limits (Pmax) are not exceeded.
Very few professionals would accept a driver that could not withstand Xmax in regular use.
Your driver not being able to withstand regular peaks reaching Xmax without damage is the exception to the rule.
Cheers,
Art Welter
Tux,
Like an engine, a speaker has displacement, the more displacement, the more output capability. Xmax, like redline, is a performance limit.
Xmax times cone area =displacement.
Engines can cheat a bit on displacement vs output, as they can be made to spin faster to extract more power cycles, while a speaker must only go at the speed of the frequency it reproduces.
Therefore, the axiom “there is no replacement for displacement” holds true for all loudspeakers.
“Redline” in a speaker is usually the equivalent of Xmech (or Xlim) which is normally quite a bit more than Xmax. Exceed Xmech and the speaker in most instances will be damaged, either instantly or over time.
Xmax, however, is by definition supposed to be within the linear range of operation for a loudspeaker. I am not familiar with all speakers of course, but speakers made by B&C, Eminence, and JBL all can withstand continuous use at Xmax as long as power limits (Pmax) are not exceeded.
Mark has recommended less than half the excursion of Xmax for safe operation on peaks, yet does not put that recommendation on the specification sheet.
Halving excursion is a reduction of approximately 6 dB, reducing power to 1/4.
Using your 112 HP, 17,000 RPM redline as an example, this is the equivalent of the bike manufacturer saying that though the engine is capable of 112 HP, only expect 28 Hp at 4250 RPM if you want the four pistons to remain in their cylinders for a full race.
I doubt you would find that acceptable.
Art Welter
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Art, et al - the debate about Xmax / Xmech or whatever new spec / testing regime is envisioned aside, might we be talking about different class of applications with your cited examples?
I doubt anyone would confuse Mark's 7, 10 or 12 cm thin metal cone drivers with the like of professional sound reinforcement / musical instrument devices, which are certainly built for the abuse to which they're guaranteed to be subjected.
5th:
the example of Adire XBL motors is well timed - I have experience with a couple of drivers ( CSS FR/WR125 and SDX7) with this tech. The motors can certainly exceed the suspension's control, with very distinctive results, and if not for the much more rugged cone materials - thicker paper on the FR/WR than Marks' EL & CHP70, and fibre mesh on the SDX7- I wouldn't be surprised if they suffered a similar fate when seriously over-driven - as it is they just fart and blat.
Hi Art,
Like my previous posts indicated, I totally agree. These drivers are finely honed, delicate devices. I agree that the manufacturer should clear about their limits. If redline is 4mm, every buyer should know, not just the buyers on this forum.
I don't even care if mark calls is xmax or xlim or what ever. Even just a note next to power handling would clear things up, and probably save him face, and sales
Like my previous posts indicated, I totally agree. These drivers are finely honed, delicate devices. I agree that the manufacturer should clear about their limits. If redline is 4mm, every buyer should know, not just the buyers on this forum.
I don't even care if mark calls is xmax or xlim or what ever. Even just a note next to power handling would clear things up, and probably save him face, and sales
The question is not whether they should be confused with the professional series of drivers or not. The question is why someone would state an Xmax of 8.5 mm when really the driver will self destruct at 4 mm.
Take the case of Fostex for example, a competing full range manufacturer. They clearly state their driver has an Xmax of 1 mm or 0.5 mm in some cases. Does this make their drivers look less attractive compared to the MA line? Yes, in some cases! But at least they do not market their drivers as being capable of an Xmax of 5 mm, coz the cone will be on the floor when that happens. Besides, these drivers will let you know that they are at their limits before self destructing. Thus it is easier to judge where the limit is. With the MA drivers it is the opposite. They operate linearly over a large portion of the Xmax and so, if they are going to fail or get damaged before reaching the stated Xmax, customers need to be warned. Not through forums, but through the legitimate method of clearly defining the T-S parameters. Something every other manufacturer, full range or otherwise, seems to know how to do.
By stating the Xmax as 8.5 mm is really misleading customers, the majority of whom will never ever visit this forum.
I'm glad some of the more knowledgeable members are stepping up to clear all this nonsense, and also that Mark is not going to get away with either deleting posts that differ from his own opinion or use deflectionary tactics such as asking members to contribute towards 'improving' his drivers.
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Mixed feelings here. I only have experience with EL70 and I am consistently impressed with how well they handle what I push through them (everything from Nini Rosso to Rage Against the Machine), but I have no "real" frame of reference. Am I pushing them beyond xmax? I have no idea, but they always sound fantastic.
On the other hand, I just sort of intuitively know when to stop turning the volume dial. I have blown speakers in the past, and each time it was because I did something really stupid, something I instictively knew I shouldn't do.
So, it seems to me that if common sense prevails, then drivers just work. For a long time. If instead we look at a series of specs and then think "hmmm, let's see about that..." then we are on a slippery slope which ultimately leads to sad faces.
However, I do believe that a speaker should start sounding bad before permanent damage sets in. Those with weaker intuition would benefit from a truly audible indication that their lack of common sense may have negative consequences; a chance to turn the volume down, before the snap, crackle, pop. Does the EL70 provide this warning? Do other MA drivers? I don't know the answer...
On the other hand, I just sort of intuitively know when to stop turning the volume dial. I have blown speakers in the past, and each time it was because I did something really stupid, something I instictively knew I shouldn't do.
So, it seems to me that if common sense prevails, then drivers just work. For a long time. If instead we look at a series of specs and then think "hmmm, let's see about that..." then we are on a slippery slope which ultimately leads to sad faces.
However, I do believe that a speaker should start sounding bad before permanent damage sets in. Those with weaker intuition would benefit from a truly audible indication that their lack of common sense may have negative consequences; a chance to turn the volume down, before the snap, crackle, pop. Does the EL70 provide this warning? Do other MA drivers? I don't know the answer...
Hi Art,
Like my previous posts indicated, I totally agree. These drivers are finely honed, delicate devices. I agree that the manufacturer should clear about their limits. If redline is 4mm, every buyer should know, not just the buyers on this forum.
I don't even care if mark calls is xmax or xlim or what ever. Even just a note next to power handling would clear things up, and probably save him face, and sales
Is it really about the specs, though? Is someone going to get out a ruler or caliper and start turning the volume knob until they start hitting xmax or xmech, or whatever?
Surely the target audience of a refined full-range driver can be expected to have some common sense and restraint. No?
Exactly right, though Xmax and Xlim do have specific definitions.Hi Art,
Like my previous posts indicated, I totally agree. These drivers are finely honed, delicate devices. I agree that the manufacturer should clear about their limits. If redline is 4mm, every buyer should know, not just the buyers on this forum.
I don't even care if mark calls is xmax or xlim or what ever. Even just a note next to power handling would clear things up, and probably save him face, and sales
The extremely thin metal has advantages and disadvantages over other materials that should be explained in the PDF, otherwise fatigue cracks are inevitable under what one would assume to be a safe operating range.
Incredible sonic detail and all that wonderful stuff is great, but so is knowing how loud a driver can go before it will break .
Can we simplify things, and not get confused.
1) All cones bend, and therefore fatigue, metal quicker than paper.
2) Time to fatigue failure depends on both the excursion, (ie degree of bending) and frequency of excursion.
3) Xmax specifies only one of these, the allowable excursion.
4) Xmech does not specify allowable frequency of excursion, so another parameter is required.
5) Perhaps one possible answer is to rate the power for "continuous", ie sinewave) and "burst", but that then requires explanation that heavy metal is closer to "sinewave" than classical is. Still not perfect.
1) All cones bend, and therefore fatigue, metal quicker than paper.
2) Time to fatigue failure depends on both the excursion, (ie degree of bending) and frequency of excursion.
3) Xmax specifies only one of these, the allowable excursion.
4) Xmech does not specify allowable frequency of excursion, so another parameter is required.
5) Perhaps one possible answer is to rate the power for "continuous", ie sinewave) and "burst", but that then requires explanation that heavy metal is closer to "sinewave" than classical is. Still not perfect.
Thanks Mark,
That figure seems more in line, and it is also a good illustration of the inherent vulnerability of full range drivers: they need light weight cones to work, whatever the material of choice. Paper will buckle as well if driven too hard.
After having read this thread, I feel a need to repeat my 'horses for courses' remark.
If in need of disco bass, use a subwoofer and a high pass on the FR.
vac
Because, by using the standard of rating an underhung motors linear excursion, the drivers do presumably have 8.5mm of one way Xmax.
If they will eventually self destruct when driven to 8.5mm one way is besides the point, the Xmax figure is still accurate. This is where Xmech comes in and defines the maximum safe excursion that the driver can repeatedly withstand without failure.
Usually Xmax<Xmech and problems aren't typically encountered.
With Marks drivers, he has chosen to keep the motor linear beyond the maximum excursion that the driver can repeatedly withstand. This is actually a very good idea. Mark has designed the drivers such that if they are occasionally over driven they will survive, but they will also still sound good when over driven. This means that for the odd classical crescendo you will be able to experience the full effect without losing out on sound quality.
With a fair few drivers Xmech = how far the driver can go before the coil slams into the backplate. And depending on the driver and how hard you slam it, this can be a trick that it will only ever get to do the once. Obey Xmech or kaboom. Slamming the voice coil into the back plate also sounds utterly horrible, it's loud and quite alarming. If you hit the back plate you literally run for volume control.
In Marks case driving beyond what would be a nominal Xmech parameter wont cause a catastrophic failure, more if you keep doing it the cone will end up deforming.
The trouble is that Mark doesn't define what the safe maximum excursion that the drivers can repeatedly withstand (Xmech) is and considering it is less then Xmax it causes confusion and, as is obvious, people end up with damaged drivers. Now it could very well be that the vast majority of those who've damaged his drivers would have ended up damaging any driver. Even so, providing an Xmech figure would give everyone something solid to work with and would presumably only help Mark out because he'd be able to say to anyone in the future who damages a driver - Xmech is clearly defined in the datasheets, if you go beyond it you've only got yourself to blame.
The "Spinal Tap " it goes to 11 types !!!
Most aren't that knowledgable..... ; ( I'm not a professional speaker design engineer; But I play one on TV !) I have real doubts wheter a spec like that is going to be appreciated and totally understood bt the novice.
I have a sneaaaaaaking suspicion that the number of MA drivers going to the big tranducer pile in the sky would be Identical even if mark were to make his spec sheets just to your liking !!!!
.
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Hi Guys,
Out of interest, I thought you might like to see a pic of the rupture testing that we do on the Multiform cone press passes (see pic). We use these test pressings to measure the tensile strength and flex ratio at each press pass.
5th's last post (No. 34) is correct re my design work (possibly a fellow driver designer/maker in the making?). The is precisely the point about this aspect of my design work, that you can use the larger excursion with linear results, on non-regualar LF loads. 5th, description of my work is better than mine. Unfortunately my partial dyslexia hinders me. Apologies to members who find my texts full of typos and a bit complex. I have to think in "word pictures", visualising engineering drawings and components, associating them with a memorised word(s) as I type. While not 100% ideal, its a method that was taught to help me manage this disability but it takes allot of time.
A few months back, I did try using X- figures as a guide for running in and general operation of a driver. I got a hail of emails and posts on exactly how do diyers go about actual measuring the physical excursion while the driver's operating. It became a nightmare so that idea sort of got scrapped.
X-Mech is a measurement of the safe regular operation for a driver?. No driver maker that I know specifically quotes an Mech measurement for the "expressed" purpose to quote a safe regular excursion load. Commonly, X-Mech (or similar) is stated as the total mechanical stroke available from the driver's power-train. So until the industry agrees a comprehensive set of standards, all I can do is to advise on regular basis on this forum. Back in June-July, I put an advice note on all Markaudio PDF's that can be downloaded from the Markaudio site. I also started the Markaudio Aren't Woofers, thread so unlike most other makers, I am trying to help.
One thing Matsubara san and me working on is more advanced rear suspensions (spiders). We are now starting to use a spider with spines. We've done allot of work to control the resistivity at the outer excursive limits. Currently, all the latest batches of Alpair 10. Gen's 2's are fitted with this up-grade (see pic). The latest design of this suspension type has additional stroke resistance from 7.2-mm onwards, but that doesn't mean its "open season" to use the Alps with this upgrade as woofs!
I'll have to think some more on how to provide data or advice that is practical to use, meaningful to the majority of end-users. Just coming up with X-Mech, X-Max, X-Zing, X-Ping, X-Thingy........whatever we call it won't hep the typical Diyer trying to figure the next project. This measurement issue has been around the block so many times already.
Cheers
Mark
Out of interest, I thought you might like to see a pic of the rupture testing that we do on the Multiform cone press passes (see pic). We use these test pressings to measure the tensile strength and flex ratio at each press pass.
5th's last post (No. 34) is correct re my design work (possibly a fellow driver designer/maker in the making?). The is precisely the point about this aspect of my design work, that you can use the larger excursion with linear results, on non-regualar LF loads. 5th, description of my work is better than mine. Unfortunately my partial dyslexia hinders me. Apologies to members who find my texts full of typos and a bit complex. I have to think in "word pictures", visualising engineering drawings and components, associating them with a memorised word(s) as I type. While not 100% ideal, its a method that was taught to help me manage this disability but it takes allot of time.
A few months back, I did try using X- figures as a guide for running in and general operation of a driver. I got a hail of emails and posts on exactly how do diyers go about actual measuring the physical excursion while the driver's operating. It became a nightmare so that idea sort of got scrapped.
X-Mech is a measurement of the safe regular operation for a driver?. No driver maker that I know specifically quotes an Mech measurement for the "expressed" purpose to quote a safe regular excursion load. Commonly, X-Mech (or similar) is stated as the total mechanical stroke available from the driver's power-train. So until the industry agrees a comprehensive set of standards, all I can do is to advise on regular basis on this forum. Back in June-July, I put an advice note on all Markaudio PDF's that can be downloaded from the Markaudio site. I also started the Markaudio Aren't Woofers, thread so unlike most other makers, I am trying to help.
One thing Matsubara san and me working on is more advanced rear suspensions (spiders). We are now starting to use a spider with spines. We've done allot of work to control the resistivity at the outer excursive limits. Currently, all the latest batches of Alpair 10. Gen's 2's are fitted with this up-grade (see pic). The latest design of this suspension type has additional stroke resistance from 7.2-mm onwards, but that doesn't mean its "open season" to use the Alps with this upgrade as woofs!
I'll have to think some more on how to provide data or advice that is practical to use, meaningful to the majority of end-users. Just coming up with X-Mech, X-Max, X-Zing, X-Ping, X-Thingy........whatever we call it won't hep the typical Diyer trying to figure the next project. This measurement issue has been around the block so many times already.
Cheers
Mark
Attachments
To be honest, I don't know how much more forewarning Mark can give about proper use of these drivers. I feel like every document and official post about his drivers include *lengthy* and *repeated* recommendations for proper use and tolerances. Now I get paranoid at the mere sight of the words 'low volume levels'.
There are people who are going to hook MA drivers up and start cranking them at the get go, or who will shrug at the fine print or think they know enough about their system to do as they see fit. It's not like there's been a record of consistent driver failure (cause if there were boy would we know about it on this forum).
This just feels like typical internet forum weather pattern with low pressure system heading Mark's way. I say ride it out.
There are people who are going to hook MA drivers up and start cranking them at the get go, or who will shrug at the fine print or think they know enough about their system to do as they see fit. It's not like there's been a record of consistent driver failure (cause if there were boy would we know about it on this forum).
This just feels like typical internet forum weather pattern with low pressure system heading Mark's way. I say ride it out.
Xmech on wikipedia is quoted as being...
I figured that this would have been lifted directly from the original T/S definitions when they were laid out. This could be considered a bit of a grey area too it seems, but regardless of that, you know that if you try going beyond it that you do so at your own risk.
I can easily see that providing details as to what Xmax to hit whilst running in at X frequency could create a whole plethora of problems. Some people wanting to know what this actually means, or wanting to know how to accurately determine it. I can however see one way around it, but then again this assumes the DIYer has access to a multimeter and a signal generator. As a PC/laptop will function as a signal generator everyone should have one of those and if the person building a DIY speaker doesn't have a multimeter then now would be a very good time for them to go and get one!
Basically you could have a run in method listed in the data sheets and it'd be very simple. You'd say something like, leave the drivers out of a box and...
1) Play a 100hz signal through the driver at a drive level of 1 volts rms for 1 day.
2) Play a 40hz signal through the driver at a drive level of 1 volts rms for 1 day.
3) Play a 40hz signal through the driver at a drive level of 2 volts rms for 1 day.
Something like that perhaps. Anyone should be capable of doing that and if they are not then they should learn how to do it. Break-in/Run-in seems like an important part of the proper way to use your drivers as it allows the more delicate of the moving parts to gradually soften up. I would say that if run-in is quite important and necessary for the best performance, that if someone doesn't know how to do something as outlined above, that they should learn out how to do it.
You could maybe also include at the end of the run-in guide.
point x) Now drive the driver at 40hz but increase the drive level up to 3.5vrms. Look at the cone and pay attention to how much it is moving. Make sure that you never exceed this amount of movement on a regular listening basis.
You can't really get much simpler/easier then that as a way of trying to quantify run-in and as giving people a visual guide as to how much they can expect their Mark Audio driver to give.
I figured that this would have been lifted directly from the original T/S definitions when they were laid out. This could be considered a bit of a grey area too it seems, but regardless of that, you know that if you try going beyond it that you do so at your own risk.
I can easily see that providing details as to what Xmax to hit whilst running in at X frequency could create a whole plethora of problems. Some people wanting to know what this actually means, or wanting to know how to accurately determine it. I can however see one way around it, but then again this assumes the DIYer has access to a multimeter and a signal generator. As a PC/laptop will function as a signal generator everyone should have one of those and if the person building a DIY speaker doesn't have a multimeter then now would be a very good time for them to go and get one!
Basically you could have a run in method listed in the data sheets and it'd be very simple. You'd say something like, leave the drivers out of a box and...
1) Play a 100hz signal through the driver at a drive level of 1 volts rms for 1 day.
2) Play a 40hz signal through the driver at a drive level of 1 volts rms for 1 day.
3) Play a 40hz signal through the driver at a drive level of 2 volts rms for 1 day.
Something like that perhaps. Anyone should be capable of doing that and if they are not then they should learn how to do it. Break-in/Run-in seems like an important part of the proper way to use your drivers as it allows the more delicate of the moving parts to gradually soften up. I would say that if run-in is quite important and necessary for the best performance, that if someone doesn't know how to do something as outlined above, that they should learn out how to do it.
You could maybe also include at the end of the run-in guide.
point x) Now drive the driver at 40hz but increase the drive level up to 3.5vrms. Look at the cone and pay attention to how much it is moving. Make sure that you never exceed this amount of movement on a regular listening basis.
You can't really get much simpler/easier then that as a way of trying to quantify run-in and as giving people a visual guide as to how much they can expect their Mark Audio driver to give.
Hi 5th, Guys,
I wondered when someone would quote Wiki. There's no original reference to this particular measurement and as said, the vast majority (if not all) driver makers aren't using this measurement is the way Wiki describes. I like Wiki allot but they aint the folks making drivers.
(Sorry 5th, I know you mean well but......)
Re 5th's running in 1,2,3 method, Please DON'T follow this pattern. Its most important to use a variable load (music) during the running in period. Regular/fixed inputs won't properly load stress the driver's power-train.
For 5th' general idea, its interesting to seek the opinions of the members for this measurement methodology.
Cheers
Mark.
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