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-   -   How to test a range of fullrange drivers? (http://www.diyaudio.com/forums/full-range/220938-how-test-range-fullrange-drivers.html)

Pnotus 4th October 2012 11:25 AM

How to test a range of fullrange drivers?
 
Hello everyone!

My first thread here - as a total newbie I am hoping to get some advice on smaller fullrange drivers in general and line array implementation spcifically.

So - IŽve gathered a couple of different drivers for testing before deciding which to use for a build.

Line up for now is:

- Aurasound neo NS3, 16 ohm version. In a buyers rage I accidentally ordered 60 of these :headbash:- so there will be a line of these anyhow.

- Visaton FRS-8M

- Faital Pro 3FE20 (Neo)

- Faital Pro 3FE25 (Ferro)

- Sica 3,5 L 1 SL

- Vifa TC9 - 8 ohm

- Vifa TG9 - 8 ohm

Perhaps coming into the mix - Fostex FE83EN and FF85WK

Any other no-brainers I have forgotten?

Now to my question:

I have built a test-baffle with exchangable loudspeaker mounting plate so that every different pair will be tried in same type of baffle.

They will be judged sonically from how they sound after a couple of hundred hours in this baffle. They will be highpassed to a Beyma Liberty-8 in a backloaded horn at whetever frequency I decide upon or will be adviced to try. Probably going to start at about 300 Hz.

But I have absolutely no knowledge about how I go about measuring the drivers. I bought this - Roland UA-55 Quad-Capture B-Stock - Thomann Cyberstore Sverige

and this to use with it - Behringer ECM8000 - Thomann Cyberstore Sverige

Where do I find literature, articles or information on how to measure these drivers accordingly? Just so I can get started and get on with some software to start to figure out how to use the data.

Regards
Pontus

Godzilla 4th October 2012 05:15 PM

Good luck with the measurements. Not sure why, but I never got into measurements? I just buy what captures my imagination, build and listen. If it sounds bad and the driver has no potential for me and my taste than I box it up and put it on the shelf... If I like something about it but the project comes out poorly, I try something else. With the drivers you list, I'd listen to them all and select the ones that sound best to me. Then maybe measure them to see what the chart looks like. But regardless of the chart, I'd listen to the one that sounds best to me. Enjoy the process!

Pnotus 4th October 2012 05:47 PM

Thank you Godzilla. I hope the process will be as enlightening as I think.

The only real reason to get som insight into measuring for me is that I want to be sure to get it right with the electronic crossover. And be able to somewhat understand what my fiddling results in sonically. Ha - weŽll see how that last part comes out.

By the way - I found an article from Stereophile written by Atkinson on measurements. Maybe that will be a good place to start.

IŽll post some pics of the test baffle and drivers. Pics always to seem to get the know-how out of the people who has it.

Also - my take on this build is somewhat similar to yours Godzilla - something captures my imagination and I want to try it. This time linearrays and fullrangers.

/pontus

tuxedocivic 4th October 2012 06:45 PM

Hi Pnotus,

For software, I use HolmImpulse and REW. REW is more powerful, but HolmImpulse is very easy to use, at least it is for me cause it's what I've always used. rpb and I put this little guide together: A HOLM starter guide

Personally I try and do my measurements outside to reduce the room effects. It's important to measure the room effects, but not when comparing drivers. Otherwise you'll swamp the driver with the room everytime.

There are plenty of online forum descriptions of how to test, but it's a good idea to get D'Appolito's Testing Loudspeakers book.

I use to just take a quick and dirty on axis frequency response. But this is a very small piece of the puzzle. Make sure you get as much data as you can or need for your purposes. Sometimes all I need is a quick on axis. But if comparing drivers, you need much more. Something to keep in mind. It seems everytime I do measurements and design, I learn more about what they mean in terms of what I hear. Keep an open mind. If one of the drivers sounds bad but measures good, you missed something.

tvrgeek 4th October 2012 11:49 PM

I use ARTA, or SoundEasy, and sometimes still use TrueRTA. I test at nearfield, 1 foot, 1 meter and usually at 15 degrees off center.

The bible on measuring is D'Apollito's book, Testing Loudspeakers. It is a bit tough for beginners, but you have to learn somehow.

Melo theory 5th October 2012 02:35 AM

Get this.

Dayton Audio OmniMic V2 Precision Audio Measurement System 390-792
It explains how to take and understand all the measurements within the program.
Also, it comes with a calibrated mic. and it's a simple USB interface.
This is what I use, it's accurate and simple.

Get this.

http://www.parts-express.com/pe/show...number=390-806
This is for impedance and TS parameters.
Very simple, also easy USB interface.

I vote for the vifa tc9.....
I used that driver in this build.
http://www.diyaudio.com/forums/multi...ambiopole.html
And I can tell you, it's glorious :)

R-Carpenter 5th October 2012 03:13 AM

For individual driver measurements or a conventional system measurements, you can use any of the Impulse capture software like Holm, ARTA or Sound Easy. Arta has a LIMP utility that measures TS and impedance of the driver/system. This option makes DATS useless and I'd stay away from it unless you have an extra $100 to give to PE.
Holm is free but somewhat limited. ARTA is free without "save option" and has everything you need to look in to the driver performance. Sound Easy is $300 and has a few powerful algorithms build in, including crossover design cad, close in capabilities to LinearX crossover design workshop.

Line arrays are difficult to measure with Impulse capture and I'd recommended using an RTA software instead.

All and all, you can use impulse to look in to the drivers performance and RTA to look in to room/speaker interaction and summed frequency response.

"Testing Loudspeakers" by D'Appolito is the recommended reading.

opc 5th October 2012 03:59 AM

7 Attachment(s)
Hi Pnotus,

There has been some great advice given already in terms of measurement, so I won't repeat too much.

I used Speaker Workshop when I was evaluating drivers for my array, and it works well for measuring a single driver in an enclosure. For the actual arrays, I use RTA as R-Carpenter suggests. You'll find the arrays very difficult to measure with an impulse.

Overall, you've got exactly the right idea for choosing a driver. Listen to each one carefully, make good notes, then measure each one and compare. That approach will help you understand what you were hearing without letting the measurements bias your listening impressions. I personally think a driver should both measure well, and sound good independently.

You can read a little more about the arrays I built here:

http://www.diyaudio.com/forums/multi...ml#post2648779

I tested quite a few drivers and ended up with the TC9FD-18-08. It sounded the most balanced and neutral, and it had very good bottom end and some of the smoothest treble I've ever heard from a fullrange.

Sorry to hear about NS3 purchase... I wasn't a big fan :(

You have a few drivers on your list that I haven't heard, the most promising of which appears to be Faital Pro 3FE25. It looks like a superb little driver with all the right qualities for an array. The C-C spacing is excellent, the response looks very even and extended, the FS is pretty low, the Xmax is reasonable and the efficiency is very very high for a driver that size. I might actually order up a few and give them a listen for fun :)

Best of luck!

Cheers,
Owen

Melo theory 5th October 2012 04:07 AM

Those are great looking arrays Owen.
I'm actually going to build an omni line array using the tc9 in a couple of weeks.

opc 5th October 2012 04:13 AM

Hi Melo,

Thanks! I really like them. the TC9 is a hell of a little driver. Even without factoring in cost it's easily one of the best, but when you consider it can be had for $6.50 in large quantities, it's in a league of it's own.

That reminds me... my overall favourite of all the drivers I tested in terms of sound and measurement was the Fountek FR88EX:

Speaker Building Supplies from Madisound

Unfortunately, at $50 each they were a little too rich for my blood. If price hadn't been a factor though, I would have built with those.

Cheers,
Owen


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