Spectrum analyzer recommendations?

  • Thread starter Thread starter notCardio
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notCardio

I walk the line
Does anyone have any recommendations for a cheap (HOME recording budget) spectrum analyzer that I could use to tune my room? I'm not looking for pro quality, I just want to get things into a reasonable state, getting rid of any glaring imbalances. I don't trust my ears enough at this point, so I need to see it in black and white, so to speak.

Thanks
 
A cheap one will do nothing to help you tune your room in the first place.

Secondly, "tuning your room" as such with EQ based on a reading from even a high-quality spectrum will not work either!

Bruce
 
True enough: a spectrum analyzer can cause more grief than it solves. But it can still be a useful tool, sometimes.

The best thing, if you're set on getting one, is to get a more versatile tool that includes a hack version of a spectrum analyzer as only one function among many other, more useful ones. I have the Terrasonde Audio Toolbox ( http://www.terrasonde.com/ ), and it does have a spectrum analysis function (both with its built-in mic and from its line inputs). It also has a useful and accurate SPL function, high-quality signal generator, distortion analyzer, frequency counter and level meter, a cable tester, and just about anything else you might think of (including a MIDI tester, a mic pre, a phase scope/tester...). The hits just keep on coming.

There are a *lot* of things that you want to be able to measure in building a studio: the frequency response of the room as measured by a spectrum analyzer is somewhat interesting, but extremely difficult to interpret and act on. On the other hand, all that other stuff is _invaluable_ to know, and it's nice to have one Swiss army knife to do the work with. The Neutrik Minirator/Minilyzer pairing ( http://www.neutrikusa.com/index.html ) is very similar, with a little more of this and a little less of that....

I spent the weekend chasing the last of the ground loops out of my rig, measuring noise floors, calibrating the VU meters, and generally tweeking things into proper alignment. Having a good tool for the job makes this gnarly chore easy. If you want to invest in some analysis tools, consider these!
 
Well, I really didn't mean with eq. I want one so that I can rearrange (or arrange, to be more truthful) the layout and experiment with different room treatments, bass traps, etc. This process will take awhile, so that's why I was looking at buying instead of renting for a day or a weekend. My "studio" is much less a studio than part of a tightly- packed basement. Like I said, I'm not expecting to compete with the pro's like yourself. I just want to try to make sure that I don't have any really obnoxious resonances.
 
That's even more reason you need to get a good unit (read, expensive!)

A cheap one will not have the resolution or fine-enough response to give you any accurate information.

The Terrasonde that Skippy mentioned is quite good, but if I recall correctly, still has some limitations that have to be taken into account when doing room analysis readings.

Other options:
A used Klark-Teknik DN-60 or the latest model DN6000 would be good - but expensive!

Bruce
 
I know you can tune a fish...but tune a room?

Bruce, if the the words "home"..."cheap" or the letters "DIY" appear in the title of the thread..Don't bother replying! Heh heh...

I might suggest tuning your ears...it an often overlooked instrument....but the most important....

Peace,
Dennis
 
Ok,the poor man's room analysis...
For a software analyzer click here.
Get a $30 Behringer ECM8000 reference mic.The white noise static between stations on the radio is spread pretty evenly across the spectrum.Record a few seconds of this white noise with the reference mic as played back through your speakers.The software will reveal the dips and peaks that defines your room tone.
I would warn you like the others not to attempt to use your EQ to "correct".But you mentioned bass traps and using absorbtive materials,so it looks like you are on the right track.
Tom
 
Thanks, guys.

Tom,

Thanks for taking me seriously enough to try and help. I've already got the mic (two actually). Pardon my ignorance, but I don't normally associate the interstation static with lower frequencies, which is one of my major concerns. I'm just trying to find out if I'm going to have any huge standing wave problems at my mixing position. I was planning on getting a test cd from Mix magazine.

Atomic,

I know my ears need training, I just want to start their training in an environment where I will have the least amount to un-learn later on.

Bruce,

I know I'm not going to get a flat room out of this, but if I can take the room's response curve from looking like Dolly Parton on her back to looking like Debra Messing (Will & Grace) on her back, I'll be more than happy. Actually, if I HAD Debra Messing on her back, I'd be more than happy (and tired, too!). But that's another subject, and better suited for the Cave. No offense intended to anyone of the female persuasion. I just had a testosterone moment. Please forgive me.
 
Cardio
The test CD is a great idea.For a test tone generator click here
It does a steady user-selectable tone or a sweep.
Tom
 
As long as we're on the topic....

Why would it NOT be a good idea to try to tame the peaks and valleys using the method I've described? I understand that eq-ing to flatten the room would potentially introduce phase problems, but why would acoustical treatments be inadvisable? Yeah, if the analyzer was grossly inaccurate, I'd end up treating the wrong frequencies and potentially make a small problem bigger, but if I can find something reasonably accurate then I don't see what the problem would be. I don't want to turn this into another diaphragm size/polarity thread, so you don't need to go into excruciatingly scientific detail, but I really would like to know what's wrong with my thinking here.

Thanks
 
Re: As long as we're on the topic....

Cardioidpotent said:
Yeah, if the analyzer was grossly inaccurate, I'd end up treating the wrong frequencies and potentially make a small problem bigger
Click to expand...
That's exactly it, a cheap unit WILL be grossly inaccurate!
 
But if I got a good one, then is there anything inherently wrong with what I proposed? And how much is a Klark-Technik DN whatever, and where would I look for one?
 
Well, yes and no.... the real problem is that room response results are not linear throughout the room... meaning, if you take a measurement at one location - and try to compensate based on that reading, you'll find that you'd get totally different readings at many different locations throughout the room.

It's sufficiently variable so that an "average" reading is not accurate enough, and so you're left back where you started!

You are far better off "learning your room" and compensating your mixes that way than what essentially amounts to chasing your own tail trying to compensate for the room's shortcomings via acoustic analysis!

As far as price - a used DN60 will run anywhere from $1500 to $2000; the new model DN6000 is around $5000.

The Terrasonde is a good unit at around $1500 (if I recall correctly!)

Bruce
 
Holy shit! The Terrasonde cost me $700 last summer at Full Compass... If it was *that* pricey, I couldn't have afforded it...

The Neutrik Minirator/Minilyzer pair is cheaper, until you realize that you have to buy the mic separately.. But they come out to about the same, once all is said and done. The advantage they have is that the signal generator is separate, so you can leave it back at the board and measure distortions/losses/phase problems with the analyzer end without having to drage a cable with you. For example, this is the kind of function you do in a live venue when you suspect that some of the drivers in the FOH stacks are installed with reversed polarity (this happens _a lot_ in clubs...). Fix that, it sounds better, everyone's happy...

Bruce has it right- it's hard to navigate all the room modes with a single-point mic, and a 10dB peak here can easily be a 5 dB dip there as you move around (or even worse, in the corners). The instrumentation can tell you a lot, but unless you've studied architectural acoustics at the graduate level, it's hard to _know_ that you're doing the right thing based on your measurements. Hell, even if you did that course of study, it's still hard. (;-).

However, don't let that stop you. The guys who do this for a living (and I'm not one of 'em!) learned the hard way what works, and you can too. As long as you don't regard the instrument as a panacea, you can use it to make relative measurements, and then calibrate the results with your ears. The instrument will never tell you conclusively what to do, or whether what you did actually _fixed_ anything: but iterative measurements and alterations will let you home in on an improved solution, over time- and you'll learn a lot.

That's why I recommend the Swiss-army-knife tools like the Terrasonde for this. You'll use it for enough of its _other_ functions over time that it will pay for itself, even if you never quite get the knack of room tuning (Gawd only knows I never have...).

But, having said that: it was nice to use the time-energy measurement function to find and kill my flutter echoes, though, and know they were dead once I had done it... It slices and dices, and many of its other functions are absolutely invaluable- especially if you work live, and occasionally need to dial things in in an all-fired hurry.
 
I'm not planning on trying to make the entire room flat (that's not even possible, is it?), just as flat as can be reasonably expected at the monitoring position.

Thanks for all the help
 
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