Another "sticky" proposition...

[Jonasz]

My projects so far have all been proven designs or modified designs tuned by ear. I think a sticky thread about measuring techniques and related stuff like recommended hardware/software could be useful for a lot of people, myself included! :B

What do you guys think?

[JonMarsh]

Sounds like a good idea- maybe a summary from each poster of what they use now, why they chose it, how they use it, etc.

Or we could just put up a link to MarkK's web site....

Should include some external refs, like sites, books, etc.

[Amphiprion]

I think we can just post "Praxis" and "LspCAD Pro" and be done with it

[TacoD]

I've used two setups in my hobby, the first could be interesting for people with limited budget but still very usefull. My latest setup is more versatile, but also more expensive. I'm aware of the freeware offerings like speakerworkshop, but in my opinion it will save time to start at a higher pricepoint (easier to use).

First of all I think you have to set the boundaries of your problem. The typical user want to come up with a cross-over for their situation (cabinet, choice of drivers, driver spacing, dimensions of the front baffle). Therefore extending on the data of the manufacturer. In that case you need a consistent and reliable method to measure the frequency respons in the used cabinet and the accompanying impedance curve. I once was that kind of user which I'll refer to as user type 1.

The more advanced user most probably want to have a calibrated setup which yields consistent and reliable measurements, while offering next to higher resolution and accuracy for the standard applications (FR, impedance) also additional features (e.g. stimuli). Of course the ability to perform distortion measurements or a convenient way to measure waterfall or polar plots. I will refer to this type of application as a type 2 user. This type of user is doing far more measurements and projects then a type 1 user.

If you are a type1 user I want to propose the following setup:
-copy of lspCAD standard with the justMLS addon*
-a proper sound card (e.g. ESI Juli@)
-Behringer UB802 mixer (for mic amplifaction)
-Behringer MC8000 mic

It is accompanied with a proper guide which will learn you a lot about combining nearfield measurements and farfield measurements, dialing in the basreflex port. But also about determining relative offset of acoustic centers.

With this setup I built appr. 20 designs with great succes. For optimizing crossovers and doing real world measurements of YOUR cabinet-driver combination it is a steal.

If you want to do more analysis then sole FR and impedance of the speakers you can use a more advanced program including xo work (e.g. soundeasy). Or stick with lspCAD and go for a more advanced measuring setup.

For the more advanced measuring setup you have also to include a better (and calibrated) mic. DIYers use the MiteyMike (sp?) or a Girardin standard mic or aco pacific (not mentioning the Bruel and Kjaer stuff from Denmark).

My main reason to upgrade was the ability to do calibrated AND more consistent measurements next to linear and non-linear distortion measurements. Also in my short DIY career I build a lot of designs (over 40) I soon found out that designing/building a speaker is very addictive and I wanted to improve on my early designs, with increasing experience I simply got more needs.

I was looking for outboard ADC's (like CLIO and ATB), but soon found out that compatibility (CLIO) or price (ATB ~3000 EURO) was quite prohibative. Another feature I was looking for was the amount of updates of the respective manufacturers. In the end I found out that Liberty Instruments was offering a lot of features and flexibility next to a lot of updates for a very reasonable price @~1300 euro. I have to say that the pioneering work of Mark_k was the final argument to order Praxis.

With regard to books/theory I've the following must reads:
The ugly duckling paper of Ingemar Johansson (cannot find it anymore though)
The D'Appolito book on measuring loudspeakers
Linkwitz' site
The sites of Mark_k and John_k
Documentation of Praxis and Clio
German pdf of Kirchner electronics on measuring (and designing a speaker) in german

ATB-pc could be a proper outsider (see last document)

[dlneubec]

I'm a novice, having been in DIY for a little over a year. I use SoundEasy. It was recommended to me by a couple people I respect in the DIY community, John Kreskovsky (Music and Design) and John Krutke (Zaph Audio). It is very complex but powerful, with a lot of options. It does have a difficult interfeace, but once you know what you want to do, it is quick and easy to use and is pretty much an all in one package that you can do all you need to do in, so far as I can tell. I only got it a couple months ago and have learned enough to take spl and impedance measurements, design and optimize boxes and crossovers and played a little bit with the distortion measurments and the digital filter capability. There is also a very active Yahoo user group and step by step tutorials available to help with the baby steps.

BTW, what is it with all the John or Jon's in the speaker building expert area? ;x(

With it I use a Behringer ECM8000 mic, a Behringer Xenyx802 Mic-Preamp, an Edirol UA-1EX Mobile USB card, my HP pavilion ZD8000 laptop and and old JVC reviever as an amp, along with various cables and a jig I created (see plan below) to make connections quicker and easier. The Behringer stuff was also recommended by a number of people. The M-Audio Transit USB was also recommended, but I had major trouble with two of them I tried to get to work with SoundEasy and WinXP Pro so I went to the Edirol, which has installed and worked without any problems.

I also picked up the idea of using a board with a bunch of binding posts, paired and single banana plugs to mock up crossovers without having long leads/alligator clips or soldering from Roman Bednarek. You can use the banana plugs to stack componenents on top of the binding posts which allows an almost unlimited number of attachment options. I have found it to be very usefull (see photo below).

I hope this is of help to other noobs.

[Amphiprion]

I use Praxis for its uber-powerful measurement capabilities and LspCAD regular (non-Pro) simply because the new regular version is almost as versatile as the old Pro version and the features of the new Pro version aren't things I'd regularly use.

I think investing heavily in the measurement side is a wise thing. With Praxis, I can not only measure speaker frequency response, but all manner of distortion, as well as other things like room acoustics, power amplifier distortion, what the built in boost of a sub plate amp is, how much distortion a bipolar electrolytic cap will introduce in the woofer crossover of a 3-way, ALL kinds of stuff. It's crazy powerful. One of my buddies even measured how much distortion inductive coupling introduced depending on how he oriented his inductors on a xo board.

For XO design, I think either LspCAD (which I use) or SoundEasy are fine. I think LspCAD 5.25 that comes packaged with v6 is the most user friendly, and I had a friend who bought SoundEasy and nearly threw his computer out the window (he isn't a patient fellow I'll admit though). I haven't had time to play around with LspCAD v6 yet and learn it so what little I've done for design work I've done in 5.25.

SoundEasy, though, is by far the most cost effective option. Just harder to learn.

Also, I've been told that Kim Girardin will calibrate ECM-8000's for $30 or so. Someone wanting a cheap calibrated XLR mic might want to look into that. Honestly the only thing it will do probably will be knock down your 5-10k range by a db or two and boost the 10k+ response of the mic if it's anything like other cheap electret condensers.

[Jonasz]

Thanks for all replies!
I think this thread starts in a great way. I hope Thomas (or Jon?) makes it a stickie. I will start to really dig into this myself in a month or two, don't really have the time right now. ops: Would be awesome though for me (and many others I bet) to have a lot of info to rely on when deciding on wich way to go in this question! :P

[ThomasW]

It won't be a stickey but it will certainly be added to our reference threads archive listed in the Mission Accomplished section.