Tried the SPL Meter, now what?!

[ExtraCheese]

I'm total noob at this hifi stuff so bear with me. I have a Denon 3805 w/ no mic. Speakers are Dynaudio 72 SE's.

The highs seemed rolled off, so I bought the radioshack spl meter to check out what is going on. I first generated tones to correspond to the RS SPL correction chart I found online. Chose the 1000hz tone and calibrated volume to 70db. Speakers are about 1 foot from the wall, room is about 22ft long, listening position is about 8ft from speakers. SPL meter is mounted on a mini-tripod.

I started the test and things seemed ok.. a few dips and peaks here and there, nothing more than +-10db. Seemed like nothing the 3805 PEQ couldn't handle. Then around 8kHz there was a big spike! and then at 10kHz it wasn't even readable!!!!!

I used a shareware test tone generator and generated test tones every 100hz from 8000 to 10000hz. Uhh.. let's just say the results were HIGHLY disturbing. The readings fluctuated wildly every 100hz, ranging from barely registering (I'd guess 50 dbs) to 75db.

What the heck is going on? I will do a more granular test tomorrow in the lower ranges but I wanted to post my findings immediatly.

 

[Buckle-meister]

I started the test and things seemed ok.. a few dips and peaks here and there, nothing more than +-10db.

Nothing more than ±10dB?! A swing of ±10dB is rather a lot I'd say.

I will do a more granular test tomorrow in the lower ranges...

You'll only find that the results get worse as the room increasingly exerts it's influence on what is heard.

I used a shareware test tone generator and generated test tones every 100hz from 8000 to 10000hz. Uhh.. let's just say the results were HIGHLY disturbing. The readings fluctuated wildly every 100hz, ranging from barely registering (I'd guess 50 dbs) to 75db. What the heck is going on?

Given that your speakers are only one foot from a wall, you're probably picking up quite severe comb filtering effects. If the listening position is also close to a wall, you'll just exacerbate this, and we've not even begun to mention room modes yet.

What is it you aim to achieve in taking these measurements?

Before launching into long discussions about interpreting results, it'd be far better if you had the entire frequency response laid out in front of you to see exactly what you're dealing with wouldn't you agree? If so, I'd recommend downloading the likes of ETF which, for just a little bit more time and effort (but not expense as the download is free) you can obtain the entire (continuous) frequency response (and much more besides) in less than five seconds. Now doesn't that sound far better?

p.s. These kinds of discussions are more suited to the Acoustics Forum...

 

[ExtraCheese]

Robbie,

In a nut shell; the sound quality compared to the money spent is no where near what I want it to be. I understand that placement and room acoustics is a big part, but since I live with my fiance, options are limited.

The problem sounds like it is in the higher frequencies. I bought the SPL meter and started testing stuff to try to quanitfy what I think I'm hearing using the meter.

Thanks for the help. I'll read up on comb effect and try the tool you recommended. If anyone else has any suggestions please post it here, I'd love to hear it, but I will post my findings in a new thread in the acoustics forum.

 

[j_garcia]

What speakers are we talking about? Do they sound bright or just not entirely clear? +/-10dB is a fairly huge swing.

Is it a "bright" room? Hardwood floors? Nothing on the walls or a lot of glass/plastic coverd framed pictures or lots of windows/hard blinds? Leather furniture? These things will tend to accentuate and/or irritate the highs.

 

[Buckle-meister]

What speakers are we talking about? Do they sound bright or just not entirely clear?

Sniper-man, ExtraCheese has Dynaudio 72 SE speakers, which being Dynaudio, are almost certainly excellent.

...I live with my fiance, options are limited.

Living in sin eh? Oh well, sorry, can't help you.

Just kidding.

Speakers are about 1 foot from the wall, room is about 22ft long, listening position is about 8ft from speakers.

I looked up your speakers. With any towers, I'd try placing them at least 2' to 3' from their back wall and away from side walls by at least the same if at all possible.

You note that the listening position is about 8' from the speakers. How far apart are the speakers themselves? Ideally you should sit between 1 to 1.5 times the distance between your speakers from your speakers, though closer to 1 if possible.

In a nut shell; the sound quality compared to the money spent is no where near what I want it to be.

I totally understand, and I'll bet the speakers sounded fabulous when you auditioned them. The problem pure and simple is that your room is negatively impacting on what you're hearing. In an ideal world, you'd treat your room, but at the end of the day everybodys circumstances/priorities are different. However, what I would say is that if you're not going to treat your room, the next best way to maximise the sound you hear is to adjust the speakers and listening position. If you take the time to do this right, either by ear or, hopefully by measurement, there's the potential for an enormous improvement.

Is your floor carpeted? If it isn't, then laying a rug between you and the speakers would help at least a little in improving the stereo image and clarity of sound. And, your fiance surely couldn't help but be impressed that you so obviously are in touch with your feminine side.

The problem sounds like it is in the higher frequencies.

As in too high, or too low?

I'll...try the tool you recommended...I will post my findings in a new thread in the acoustics forum.

If you need any help in getting ETF hooked up, just let me know.

 

[AudioSeer]

Dynaudio's are notorius for needing room to breathe. You should have these at least 3 feet away from any wall. If you want to place them so close to the wall, you probably want to switch to speakers that were designed for near wall placement.

Was the spl meter placed at the listening position? Room treatments at the first reflection points (don't forget floor and ceiling) can help.