Speaker analysis is hard, so 1m measurements are the way to go!

[eriksquires]

Hey everyone,

I wanted to post a think-piece about learning to do speaker analysis. In particular for a beginner starting out with a 2-way system and using in-room measurements may be the very best way to get started.

Of course there will be room interactions not fully accounted for, but maybe a measurement which gates the tweeter/mid-woofer crossover areas and then blends that with the mid-woofer's low end response is the best way to get started?

With 1m measurements there are a few complications we avoid (compared to quasi-anechoic), such as:

1. Integrating the port (if any) with the woofer response
2. Adding baffle step calculations
3. Understanding boundary reinforcement and how that will shape the final outcome.

Even with 1m measurements there are still a couple of things which are going to be a little difficult:

• Measuring the acoustic offsets
• Measuring off-axis to pick ideal crossover location.

What do you all think of this as a solid learning path for most beginners? Would you suggest another direction instead?

 

[picowallspeaker]

There's a soundfield created by two sources, in stereo.
There are no room interactions, it's the sound that propagates and collides on hard surfaces and refracts, reflects, diffracts at angles and holes.
What you catch at 1 m on axys is only the amplitude ( magnitude- scalar) of a vector.

 

[andy19191]

What do you all think of this as a solid learning path for most beginners? Would you suggest another direction instead?

I would suggest reading a book as the efficient tried and tested way to get from knowing nothing to having an idea of where to look for guidance on what is not understood.

 

[eriksquires]

There's a soundfield created by two sources, in stereo.
There are no room interactions, it's the sound that propagates and collides on hard surfaces and refracts, reflects, diffracts at angles and holes.
What you catch at 1 m on axys is only the amplitude ( magnitude- scalar) of a vector.

What exactly are you suggest is a better learning path for beginners?

 

[eriksquires]

I would suggest reading a book as the efficient tried and tested way to get from knowing nothing to having an idea of where to look for guidance on what is not understood.

Of course. My point was meant to ask, for absolute beginners, whether or not attempting to do a fully quasi-anechoic analysis of a speaker is the best approach or not.

I'm very much afraid the spirit and background of my original post is getting lost. When I talk to a lot of DIY'ers who are just starting to mod speakers it seems to me their enthusiasm is somewhat blunted by the difficulty of complete measurements. Given that and my desire to see more people enjoy the hobby I posited that encouraging messy but good approaches is useful.

 

[anibal]

Check the book "Measuring Loudspeakers" by Joe D'appolito.
It is a great book, full of useful information and wrote as simple as possible to deal with this task.

 

[A4eaudio]

...My point was meant to ask, for absolute beginners, whether or not attempting to do a fully quasi-anechoic analysis of a speaker is the best approach or not.

... When I talk to a lot of DIY'ers who are just starting to mod speakers it seems to me their enthusiasm is somewhat blunted by the difficulty of complete measurements.

My opinion...

Yes, given today's tools it doesn't make sense to not take good on- and off-axis measurements with a dual channel setup. The goal is to make something DIY as good, or better, than commercial offerings. But if you aren't going to do it right, you can get perfectly acceptable performance from new, or especially used, speakers.

I wouldn't bother buying a book. There are 5 to 10 page Internet write-ups that explain what needs to be done.

 

[Scottmoose]

Jeff Bagby's straightforward suggestions (which is exactly what they are) remain about the best 'simple' guide that I'm aware of, in terms of producing data that's actually useful:

http://audio.claub.net/software/FRD...curate In-Room Frequency Response to 10Hz.pdf