DATS V2 and Infinity PS 10 Driver

[Swerd]

IMO, Zobel networks (for impedance compensation) should be used when designing passive crossovers on all drivers that show a significant increase in impedance with rising frequency.

I agree. Just how big an increase in impedance does it take before it becomes significant? Fig. 3-4 from Elliot's article is a good example. The red trace shows impedance vs. frequency without Zobel correction, and the green trace shows the same driver with Zobel correction.

In his text, Elliot says:

"Unless the impedance remains reasonably constant for at least 2 - 2.5 octaves above and below the crossover frequency, the network cannot be expected to provide a predictable response. As a direct result of this, a 6dB/octave passive crossover at (say) 300Hz is barely acceptable, because of the impedance peak of the woofer."​

It really depends on the intended crossover frequency and slope. I don't think impedance of 10 ohms at roughly 800-1000 Hz is unacceptably large. But 20 ohms impedance at or above 2000 kHz is too large.

Based on the resonance frequency below 30 Hz, I'd guess this driver is a large woofer, maybe 8" or larger. I can easily imagine it used in a 3-way speaker, but not as a 2-way. I also would not try to make it work with a 1st order crossover slope, when a 4th order slope is very easily done. I also wouldn't choose a crossover frequency or a slope based on the impedance curve alone. I would at least want to see the SPL vs. frequency curve.

In short, trying to correct a driver's impedance outside the intended pass band is a waste of effort.

Discussing Zobel networks in a subwoofer does seem to be off-track.

 

[Verdinut]

I agree. Just how big an increase in impedance does it take before it becomes significant? Fig. 3-4 from Elliot's article is a good example. The red trace shows impedance vs. frequency without Zobel correction, and the green trace shows the same driver with Zobel correction.
View attachment 28240
In short, trying to correct a driver's impedance outside the intended pass band is a waste of effort.
.

I agree. It's also a waste of money!

You say that discussing Zobel networks in a subwoofer does seem to be off-track. No, it's not always the situation.

For example, I did use a Zobel network on a Dayton RSS315HF-8 sub which I installed in a 3-way system. This speaker enclosure uses a 2nd order Linkwitz-Riley XO with a 270 Hz filter frequency connecting to a pair of SB Acoustics 5½ inch midbass drivers.

Here is the impedance curve for the system which I believe is pretty good compared to curves of some expensive commercial speaker designs:

 

[Alex2507]

Discussing Zobel networks in a subwoofer does seem to be off-track.

Yeah, that's what I was doing. Not from a perceived need for one but because the DATS V2, subwoofer and User's Guide article on Zobel Networks are happening at the same time. I thought I could lower the second impedance peak (55 Hz) which coincides with ~40 degree phase angle. Maybe that is a perceived need. Anyway, I appreciate the links and discussion.

 

[Alex2507]

I agree. It's also a waste of money!

You say that discussing Zobel networks in a subwoofer does seem to be off-track. No, it's not always the situation.

For example, I did use a Zobel network on a Dayton RSS315HF-8 sub which I installed in a 3-way system. This speaker enclosure uses a 270 Hz filter frequency XO connecting to a pair of SB Acoustics 5½ inch midbass drivers.

Here is the impedance curve for the system which I believe is pretty good compared to curves of some expensive commercial speaker designs:

How do you link that attachment? That would be a huge help.

 

[Verdinut]

How do you link that attachment? That would be a huge help.

You need to install a free Adobe Acrobat Reader which is easily available to download from Adobe's website.

 

[Verdinut]

How do you link that attachment? That would be a huge help.

I've just posted the .jpg file in replacement of the .pdf one

 

[Swerd]

If I click on the Attach files button

,
I get choices of what file formats I can up load. (see figure below). The choices are below (Hint: pdf is third on the list):

• zip
• txt
• pdf
• png
• jpg
• jpeg
• jpe
• gif

 

[Alex2507]

DATS V2 exports in CLIO Formatted .txt

 

[Alex2507]

You need to install a free Adobe Acrobat Reader which is easily available to download from Adobe's website.

I can see your graph but not mine.

Still working on it, I guess.

 

[Swerd]

Once you've uploaded an attached file, scroll down to see this. You get to choose whether your attachment is shown as a Thumbnail or as a Full image. Your previous post shows Thumbnails. You can edit a post with an attachment and change how it appears.

 

[Swerd]

Just read your question again. Now I think I get what you're asking. This is not a matter of how AH uploads and displays files, it's a matter of how the cabinet design software you have (DATS, Bass Box?) can show various results and save them in various formats.

The files you attached in your post #28 are called CLIO files. They show all the data for frequency response or impedance curves in numerical form. (If you save them as txt files, you can load them into other graphing applications, such as Excel.)

I don't have that software in my hands, but you want to save a pdf file of the graphed data. Do I have that right? You'll have to look for it inside that software. It must exist, but I can't help, sorry. Try the software's help section. Maybe Verdinut can help.

 

[Verdinut]

I can see your graph but not mine.

Still working on it, I guess.

Look at post #22 again. I replaced the pdf file by one with a . jpg extention.

My printer gave me the problem. Isn't that stupid, when I specify a black and white document to be scanned, it tranfers it to a pdf extension. So, I specified that the document was in color, although it was only in black & white, and the printer provided a document with the .jpg extension.

Your problem is solved for that post.

 

[Swerd]

I can see your graph but not mine.

Still working on it, I guess.

I know this doesn't really address your problem, but I spent some time messing with Excel and eventually got your CLIO data plotted in a presentable manner. I tried to get the Frequency axis to appear at the bottom instead of the top, but couldn't. I also wanted the Impedance axis to appear on the left side, with the Phase Angle axis on the right side. Again, I couldn't get things to behave the way I wanted. Graphing in Excel was always complex & non-intuitive for me – just like all Microsoft programs. Anyway, I hope its at least understandable.

 

[Alex2507]

I replaced the pdf file by one with a . jpg extention.

.pdf and .jpeg are not export options but .zma, .txt and .tzz. So to start with, there isn't a .pdf file for me to replace.

There are 2 .txt options. One is CLIO formatted and the other is DATS formatted. This might be a DATS V2 specific condition. I downloaded Adobe but that's not giving up any easy answers.

I spent some time messing with Excel and eventually got your CLIO data plotted in a presentable manner.

Thanks! That's the graph, alright. Because of the phase angle it's telling me that this sub in this box is useable from about 25Hz to 55Hz. Oddly enough the phase angle and the impedance peaks shift, if I stuff the port. Another in these series of baby steps to understanding, is watching the Q(ts) grow as the box gets bigger. At least I know I don't want that.

EDIT: I may have to get imagur but really don't want to have to figure out another computer thing.

EDIT 2: Got Imgur and could do the drag and drop thing with this:

http://imgur.com/rJBa3b6

but not with the files from DATS V2.

BTW, we had company so I had to clean up. Those little P140s were on the dresser (temporarily wall mounted)

http://imgur.com/558LRlS

http://imgur.com/FJ7pPDI

but the dresser is going to be replaced by the bass cab portion of Dennis' speakers

http://imgur.com/KTX8Wve

http://imgur.com/z5CHNq8

Yeah, so imgur (finally got the spelling right) works great. But not for dats v2 exported file/pic/do-hickeys. F^%&.

 

[Swerd]

Yeah, so imgur (finally got the spelling right) works great. But not for dats v2 exported file/pic/do-hickeys. F^%&.

I'll try to help, but no promises that anything I can think of will work.

If I understand your problem, DATS v2 allows you to see a plot of your measurements on your computer screen. You can print it, but you don't know how to save the plot as a file that you can post online as an attachment. Is that correct?

I read the first 3 pdf files available here & looked for any specific comments about printing or saving files. I didn't download the software or read the warranty, items 4 & 5 on that list.

The DATS v2 Quick Start Guide says on page 2, item 9:

9) After measuring the speaker you can:

• Save the data to one of 20 project memories (Alt+1 saves to Memory 1 for example)
• Save a DATS V2 project file (file extension .tzz) which includes your test setup and all 20 memories
• Export the parameters and impedance data in either .txt or .zma formats
• Overlay plots of various measured impedances from the 20 memories for detailed comparison
• Print a report showing the impedance and parameters of the displayed memories

If I understand this correctly, you can save up to 20 different test results of a project by pressing Alt1. You can also save a DATS V2 project file that keeps your test setup conditions, and all 20 saved readings. These files can be exported as .txt or .zma file formats. I think we all are familiar with .txt files, they contain plain text. I had to search Google for a definition of .zma file:

What is a ZMA file? Data file created by the SPL Tracer, a speaker frequency response and impedance graph tracer application; contains speaker data, such as impedance level units and phase information necessary for drivers; similar to .FRD files. The first link on the Google hit list was this https://fileinfo.com/extension/zma.​

OK, so far nothing stands out. All I can suggest is:

1. When you save a project, exit DATS v2, and look for files in the folder where you saved it, either in your C drive, your desktop, or that damn Cloud. Try clicking directly on a .zma file and see what happens. Can you open a zma file as a picture or image without having DATS v2 open?
2. When you have DATS v2 open and you print a report (as on the 5th bullet point above) you will probably get the usual Windows dialog box. It probably already has your printer selected, like this
   
3. 
   Where it names your printer, try using the pull-down arrow to see what other choices are available. Is Adobe Acrobat PDF one of those choices? If so, click on it, and print. Instead of operating your printer, the image is saved as a PDF file. It will ask you the usual questions about naming and locating this new file.
4. If printing does not show you a PDF option, try SAVE AS, and look for what types of choices you have. Is PDF one of them?

That's all I got for now. Maybe Parts Express has a useful answer.

 

[Verdinut]

.pdf and .jpeg are not export options but .zma, .txt and .tzz. So to start with, there isn't a .pdf file for me to replace.

Another in these series of baby steps to understanding, is watching the Q(ts) grow as the box gets bigger. At least I know I don't want that.

For a woofer or a subwoofer, if the Qts is low, you won't get much low frequency output. This is what happens with most high sensitivity pro audio drivers.

With a Qts below 0.30, you won't get much LF performance in a ported box, but with a well built driver having a low Fs and a Qts of 0.38 up to 0.45, you should be able to obtain good and smooth LF provided that the box is properly tuned.

 

[Verdinut]

.pdf and .jpeg are not export options but .zma, .txt and .tzz. So to start with, there isn't a .pdf file for me to replace.
QUOTE¨]

@Alex2507,

I don't understand your point when you mention that .pdf is not an export option. I always download .pdf files from various commercial websites.

BTW, did you see the .jpg image of the impedance curve at post #22?

Cheers,

 

[Alex2507]

I don't understand your point when you mention that .pdf is not an export option. I always download .pdf files from various commercial websites.

BTW, did you see the .jpg image of the impedance curve at post #22?

Yes, of course I saw the image in post 22.

.pdf is not an export option from that DATS V2. I can get jpeg and pdf files from the internet as well. The point/problem is that I can't get them from the DATS V2.

If I understand your problem, DATS v2 allows you to see a plot of your measurements on your computer screen. You can print it, but you don't know how to save the plot as a file that you can post online as an attachment. Is that correct?

You got it.

Try clicking directly on a .zma file and see what happens. Can you open a zma file as a picture or image without having DATS v2 open?

zma is also text. tzz is the file type for pic's that won't upload into Photobucket or imgur. Those files go to 'Documents' and I can access them readily.

Is Adobe Acrobat PDF one of those choices?

Nope.

If printing does not show you a PDF option, try SAVE AS, and look for what types of choices you have. Is PDF one of them?

Microsoft print to pdf is a print option that goes nowhere atm. There's something about these files and the term 'supported file types' that don't go together. To see them in 'Documents' when I want to upload them I have to click on 'All Files' to see them as opposed to 'supported file types'.

Maybe Parts Express has a useful answer.

You know, I bet they have that lifetime customer support # that I could call. That's the answer.

Kind of interesting: There are two of these PS 10 subs. The QTS numbers are 1.0 and 1.6. The impedance/phase plots are almost identical but the Q is way off. They were bought at different times and the amp had blown on the 1.6 Qts sub which prompted me to disable the amp in the 1.0 sub. I'll play around with them more as I have time/ambition. I just thought that was weird.

 

[everettT]

Yes, of course I saw the image in post 22.

.pdf is not an export option from that DATS V2. I can get jpeg and pdf files from the internet as well. The point/problem is that I can't get them from the DATS V2.




You got it.



zma is also text. tzz is the file type for pic's that won't upload into Photobucket or imgur. Those files go to 'Documents' and I can access them readily.



Nope.



Microsoft print to pdf is a print option that goes nowhere atm. There's something about these files and the term 'supported file types' that don't go together. To see them in 'Documents' when I want to upload them I have to click on 'All Files' to see them as opposed to 'supported file types'.



You know, I bet they have that lifetime customer support # that I could call. That's the answer.

Kind of interesting: There are two of these PS 10 subs. The QTS numbers are 1.0 and 1.6. The impedance/phase plots are almost identical but the Q is way off. They were bought at different times and the amp had blown on the 1.6 Qts sub which prompted me to disable the amp in the 1.0 sub. I'll play around with them more as I have time/ambition. I just thought that was weird.

Use prntscrn (print sceen) key and then open ms paint and hit paste... save as jpeg.

 

[Alex2507]

Thanks Everett. You win the internet today.

EDIT: Just seeing if Photobucket has bigger pic's

Good Amp:



Bad Amp:



This is the beginning, I'll get better at this. These are two PS 10 drivers. They were bought at different times and the most notable difference is the Qts. Measurements are from in cabinet w/ amps bypassed.