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**neildavis** · 11-14-2012, 08:20 PM

Re: Measured T/S Parameter Thread Sticky

Originally posted by mattp View Post

Hey all,

In the last few years I have conjoured up quite a databass of measured parameters through the WT3 that I figured I would post in case someone wanted "third party data" for any of the drivers that may have passed by my desk...

This seems like a good opportunity to think about a useful on-line T-S database. Excel and .NET programs can access remote databases, but it is going to take some work to define a useful online storage that multiple programs could use and easily update. Seems like a worthwhile effort awaiting a database guru to lead.

There have been other earlier attempts that weren't very successful. Jan Fredriksson had initiated a T-S database and set up a web site for it at www.thielesmall.com. However, there wasn't a web interface that made it easy to bring the data into Excel or other programs. He has over 5000 drivers in that database, but I think it is fair to say that most of the entries at this time are obsolete. The last time the driver data was verified was 2004, and at that time about 35% of the drivers were no longer in production. I copied all of that data into Excel, but in scanning through I wasn't overly impressed at the usefulness of the data.

I've got all of the PE woofer selection guide in a Microsoft Compact database, and it looks like MCM finally has something comparable to PE's selection guide that could be imported into this database. I could add the useful parts of the thielesmall database, but it will take some time to weed out the old stuff that doesn't add much value. With Matt's contributions we should be able to start with a couple of thousand drivers with useful data.

If someone could figure out how to collaboratively add new entries without having spam or crap take over, then this might be a useful resource. I'd be happy to host the data on Audiodevelopers.com, but I need to know that any updates will be "secure".

Any thoughts?

**thekorvers** · 11-14-2012, 10:05 PM

Re: Measured T/S Parameter Thread Sticky

Any chance of FRD files to be somehow included in this database as well? I think that would be immensely useful.

We have longed for a repository of these type of parameters and files, easily accessible in one place, for a long time. I realize that the files would be much larger and require more space. I also understand that there is time and effort involved in the posting and maintenance of the site, but I for one would not mind paying a small subscription fee of some type to be able to access this information.

You could even offer an incentive to anyone providing files in the form of a free subscription to the repository for a period of time.

Just a thought!

**mattp** · 11-15-2012, 01:42 PM

Re: Measured T/S Parameter Thread Sticky

Continued...

Aurum Cantus AC120/50CK 5" Midwoofer (296-440)
Re: 7.48 ohms, Fs: 55.85 Hz, Qts: .508, Qes: .55, Qms: 6.616, Le (1kHz): 0.196 mH, Vas: 0.339 cuft, Effective Diameter: 3.875"

Usher 8945P 7" Carbon Fiber/Paper Woofer w/Phase Plug (Discontinued, 296-602)
Re: 5.863 ohms, Fs: 34.32 Hz, Qts: .367, Qes: .435, Qms: 2.369, Le (1kHz): 0.765 mH, Vas: 1.232 cuft, Effective Diameter: 5.5"

Usher 8137A 8" Kevlar/Carbon Fiber Woofer (296-616)
Re: 5.706 ohms, Fs: 31.63 Hz, Qts: .4323, Qes: .5266, Qms: 2.414, Le (1kHz): 0.7678 mH, Vas: 2.511 cuft, Effective Diameter: 6.5"

Morel CAW 538 5" Cast Frame Woofer (297-082)
Re: 5.399 ohms, Fs: 56.52 Hz, Qts: .498, Qes: .647, Qms: 2.164, Le (1kHz): 0.751 mH, Vas: 0.3258 cuft, Effective Diameter: 4"

Morel Ultimate UW 1058 10" Subwoofer (297-130)
Re: 6.514 ohms, Fs: 30.28 Hz, Qts: .536, Qes: .699, Qms: 2.288, Le (1kHz): 2.01 mH, Vas: 1.548 cuft, Effective Diameter: 8.125"

HiWave BMR12 Compact 2" Full-Range Square Speaker 12W 8 Ohm (297-210)
Re: 7.976 ohms, Fs: 170.2 Hz, Qts: .669, Qes: .945, Qms: 2.288, Le (1kHz): 0.308 mH, Vas: 0.007 cuft, Effective Diameter: 1.75"

HiVi D5G 5" Kevlar/Paper Woofer (Discontinued, 297-419)
Re: 6.678 ohms, Fs: 57.2 Hz, Qts: .498, Qes: .577, Qms: 3.642, Le (1kHz): 1.346 mH, Vas: 0.141 cuft, Effective Diameter: 4.125"

HiVi B3N 3" Aluminum Driver Round Frame (297-428)
Re: 6.629 ohms, Fs: 107.7 Hz, Qts: 1.013, Qes: 1.323, Qms: 4.315, Le (1kHz): 0.2622 mH, Vas: 0.0306 cuft, Effective Diameter: 2.5"

HiVi D5.8 5" Poly Bass/Midrange Shielded (297-439)
Re: 6.374 ohms, Fs: 70.66 Hz, Qts: .559, Qes: .611, Qms: 6.503, Le (1kHz): 1.24 mH, Vas: 0.1 cuft, Effective Diameter: 4.125"

HiVi F6 6" Bass/Midrange (297-440)
Re: 6.56 ohms, Fs: 51.14 Hz, Qts: .505, Qes: .561, Qms: 5.056, Le (1kHz): 1.01 mH, Vas: 0.6043 cuft, Effective Diameter: 5.25"

HiVi M6a 6" Aluminum/Magnesium Midbass (297-442)
Re: 6.708 ohms, Fs: 57.87 Hz, Qts: .597, Qes: .659, Qms: 6.326, Le (1kHz): 0.463 mH, Vas: 0.4899 cuft, Effective Diameter: 5.125"

HiVi D6.8 6" Poly Bass/Midrange Shielded (Discontinued, 297-444)
Re: 6.453 ohms, Fs: 52.49 Hz, Qts: .543, Qes: .619, Qms: 4.481, Le (1kHz): 1.371 mH, Vas: 0.3081 cuft, Effective Diameter: 4.75"

HiVi F8 8" Bass/Midrange (297-445)
Re: 6.477 ohms, Fs: 41.72 Hz, Qts: .441, Qes: .476, Qms: 6.032, Le (1kHz): 1.352 mH, Vas: 1.03 cuft, Effective Diameter: 6.5"

HiVi M8N-1 Aluminum/Magnesium Woofer (297-446)
Re: 6.539 ohms, Fs: 41.05 Hz, Qts: .655, Qes: .727, Qms: 6.617, Le (1kHz): 1.383 mH, Vas: 1.364 cuft, Effective Diameter: 6.5"

HiVi D8.8 8" Poly Bass/Midrange Shielded (297-449)
Re: 6.484 ohms, Fs: 37.01 Hz, Qts: .419, Qes: .466, Qms: 4.117, Le (1kHz): 1.746 mH, Vas: 0.8358 cuft, Effective Diameter: 6.75"

Aura NS6-255-8A 6" Paper Cone Neodymium Magnet Woofer (299-030)
Re: 7.08 ohms, Fs: 47.1 Hz, Qts: .503, Qes: .529, Qms: 10.27, Le (1kHz): 1.137 mH, Vas: 0.877 cuft, Effective Diameter: 5.75"

6-1/2" Aluminum Cone Shielded Driver (299-101)
Re: 6.442 ohms, Fs: 51.14 Hz, Qts: .489, Qes: .537, Qms: 5.416, Le (1kHz): 1.069 mH, Vas: 0.5785 cuft, Effective Diameter: 5.25"

Peerless 830872 4" HDS Nomex Shielded Woofer (299-240)
Re: 5.638 ohms, Fs: 83.44 Hz, Qts: .4468, Qes: .5784, Qms: 1.962, Le (1kHz): 0.6378 mH, Vas: 0.0571 cuft, Effective Diameter: 3.25"

Peerless 830862 5-1/4" HDS Shielded Woofer (299-242)
Re: 6.071 ohms, Fs: 59.22 Hz, Qts: .493, Qes: .5634, Qms: 3.941, Le (1kHz): 0.3076 mH, Vas: 0.3105 cuft, Effective Diameter: 4.125"

5" Concave Paper Cone Woofer Speaker 2 Ohm (299-289)
Re: 1.722 ohms, Fs: 59.22 Hz, Qts: .53, Qes: .611, Qms: 3.987, Le (1kHz): 0.448 mH, Vas: 0.2125 cuft, Effective Diameter: 4"

Usher 8948A 7" Carbon Fiber/Paper Woofer (296-603)
Re: 5.94, Fs: 31.63 Hz, Qts: .326, Qes: .385, Qms: 2.135, Le (1kHz): 0.714 mH, Vas: 1.793 cuft, Effective Diameter: 5.5"

This is what I have so far. Feel free to add more as you wish.

-M

**mattp** · 11-15-2012, 01:44 PM

Re: Measured T/S Parameter Thread Sticky

Originally posted by thekorvers View Post

Any chance of FRD files to be somehow included in this database as well? I think that would be immensely useful...

I agree.

Unfortunately we do not have time or man power right now to be able to do any anechoic testing. Hopefully that will change in the future.

**kevinr** · 11-15-2012, 01:45 PM

Re: Measured T/S Parameter Thread Sticky

Thanks Matt

**thekorvers** · 11-15-2012, 02:28 PM

Re: Measured T/S Parameter Thread Sticky

Originally posted by mattp View Post

I agree.

Unfortunately we do not have time or man power right now to be able to do any anechoic testing. Hopefully that will change in the future.

I realize that. However I believe that there are a substantial number of these files created by various people which are located all over the place, including people's hard drives.

I am more thinking along the lines of the creation of a repository of some type and get people to submit their files for inclusion along with any T/S parameters they may have. You yourself would not need to do any anechoic testing.

The obvious place to host this would be on the PE website rather than on someone's personal website. I would be willing to bet that this would increase PE's sales.

As I mentioned in the other (related) thread, I for one would not be averse to paying a small subscription fee to access the information in order to offset the cost of maintenance of this database. The idea of a repository for this data has been discussed a number of times before, but never reached fruition. If we could achieve this, it would be a boon to our DIY community!

If this idea is taken into consideration by PE, you could solicit ideas on what data to include and how to set up this repository/database.

Thank you for your consideration.

**mattp** · 11-15-2012, 02:50 PM

Re: Measured T/S Parameter Thread Sticky

That is a good idea and you're right, there are probably hundreds of files floating around here that would be beneficial to everyone on the forum. I'll see what I can do about creating an .frd/.zma database that everyone can access when needed.

If anyone has files they wouldn't mind sharing, you can either PM me email them to me at mattp (at) partsexpress (dot) com.

**killa** · 11-15-2012, 03:41 PM

Re: Measured T/S Parameter Thread Sticky

The problem with sharing frd is that you need to know exactly how they were measured. Things like baffle size, distance, and spl. There needs to be a standard or a description of how they were measured.

**neildavis** · 11-15-2012, 03:50 PM

Re: Measured T/S Parameter Thread Sticky

Originally posted by killa View Post

The problem with sharing frd is that you need to know exactly how they were measured. Things like baffle size, distance, and spl. There needs to be a standard or a description of how they were measured.

Bingo! The FRD file is just a simple fixed-format file, without metadata. There is no way to describe the data inside the file without causing some design tools to "break". So either the FRD format needs to be extended, or else the FRD data needs to get stored in a database that can hold the FRD data plus metadata. Either approach will work, but it's going to take some work to define the extensions and/or set up the database.

**dlr** · 11-16-2012, 10:25 AM

Re: Measured T/S Parameter Thread Sticky

Originally posted by neildavis View Post

Bingo! The FRD file is just a simple fixed-format file, without metadata. There is no way to describe the data inside the file without causing some design tools to "break". So either the FRD format needs to be extended, or else the FRD data needs to get stored in a database that can hold the FRD data plus metadata. Either approach will work, but it's going to take some work to define the extensions and/or set up the database.

If you look at the new file format Bill Waslo (whose extensions were the impetus for the frd/zma we use as a standard name) created for his more recent Praxis software (px2/pxd), you'll see it has additional detailed data up front using the first 124 lines in the pxd. I'm sure he uses this so that the program could re-create the px2 (a compressed version I believe). Praxis also can export the old frd type format as well.

It sounds like the desire is for a simple version of this. The problem will be that once a format is chosen, whoever codes for use will be advised to make the file read/save flexible so that the up front informational area can expand if desired. Another issue, though, is that this data area would be useful and identifying specific data within the format will be strongly suggested. I believe that this is how Bill did it within a pxd file. There appear to be tags within it. It might even be that we should consider adopting Bill's pxd as a replacement for frd and his version of the old zma as well, although I think that he has a single extension with the first line being the identifier of the type, it's been a while since I've used the free version of Praxis. I like this idea in a way , except that when you're loading a file, it's good to have specific extensions as identifiers. We'd also probably have to get Bill's acceptance and some input into the format he uses.

The free version of Praxis has a whole host of excellent post-processing stuff, including tailing, Hilbert-Bode phase generation, etc. I'm surprised at how few here use it, especially since the post-processing functions are provided in the free version. Just the curve display ability makes it one of the most useful pieces of software I've ever found for measurement display. I've used it extensively at my site. Hat's off to Bill for one the best user-friendly UI's I've ever encountered.

We could even use it as a processor to read in anyone's frd/zma files and then export to his px2 or pxd. Then both would be available and no change would be required of the current frd format, since Praxis is available to do the conversion both ways. Otherwise we're re-creating the wheel, so-to-speak. The tools are availabe now.

dlr

**dlr** · 11-16-2012, 10:34 AM

Re: Measured T/S Parameter Thread Sticky

Originally posted by killa View Post

The problem with sharing frd is that you need to know exactly how they were measured. Things like baffle size, distance, and spl. There needs to be a standard or a description of how they were measured.

I think this does go beyond my previous post about using Bill Waslo's extension. You can enter info on a line for display, but I'm not sure just what data is embedded. Praxis reads the older LAUD files, his previous product that I use and I'm not sure what data is used. Certainly there's nothing that identifies specifics as being discussed here.

I don't think the file should include this sort of data. The db would be the place for that so that the user could then decide what to do if anything.

dlr

**Pallas** · 11-16-2012, 10:56 AM

Re: Measured T/S Parameter Thread Sticky

Originally posted by mattp View Post

Aura MR-18.4 18" NRT Subwoofer Speaker (269-187)
Re: 3.382 ohms, Fs: 21.53 Hz, Qts: .492, Qes: .593, Qms: 2.847, Le (1kHz): 1.707 mH, Vas: 6.8 cuft, Effective Diameter: 15.25"

I think the Le might be off by a decimal place here.

If memory serves, my NS18-992-4A measured in the 0.2mH range. I thought the MR18.4 was just the NS18 with a funky colored cone and different basket paint. If it doesn't have the copper sleeve on the motor than the NS18 has, never mind.

**mattp** · 11-16-2012, 02:27 PM

Re: Measured T/S Parameter Thread Sticky

Originally posted by Pallas View Post

I think the Le might be off by a decimal place here.

If memory serves, my NS18-992-4A measured in the 0.2mH range. I thought the MR18.4 was just the NS18 with a funky colored cone and different basket paint. If it doesn't have the copper sleeve on the motor than the NS18 has, never mind.

Not sure about the copper but the decimal is in the right place.

**Pallas** · 11-17-2012, 03:46 PM

Re: Measured T/S Parameter Thread Sticky

Originally posted by mattp View Post

Not sure about the copper but the decimal is in the right place.

Odd. Maybe the motors are different between the Aura MR and Aura NS series, because I just looked up my NS18-992-4A and I measured 0.35mH on it. I also just measured my NS15-992-4A (the NS18 being less convenient to reach; they use the same 4" vc motor) and got 0.41mH on it. 0.4133mH, if one demands the 'precision' provided by a WT3.

Has anyone measured the Aura MR12.4 that PE was closing out? I have three different NS12-794-4A's and can measure the Fs and Le of each.

(Note: nothing else to contribute here because I never measure complete T/S any more. Getting a good Vas measurement is time-consuming, and I don't see much point in it unless one is doing some sort of vented or bandpass box. Which I never do any more. Really, I just measure impedance peaks and derive Qtc of finished closed boxes.)

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