this is the result from measuring HS80m frequency response by Room eq wizard

[bluesj]

I used Emu 1616, Radio shack analog SLM and yamaha HS80m
when I mesaured the frequency response in my living room, I hold SLM 4.5inch away from the middle point between Hs80m tweeter and woofer for accuracy

this is for only one speaker...(not pair ,two)

[Guitar Zero]

Are you sure that's not the frequency response curve of the mic?

[Kiwiburger]

I would say that is the combined frequency response of the speakers and microphone. The converters are probably flat enough not to worry.

Was that pure white noise you were pumping into the room? Does that source noise yield a flat graph?

At 4.5 inches away from the speaker box, I doubt there is much room influence at all - unless you have major boomy room nodes.

It takes scientific equipment to measure a room - and even then, you will get totally different results at different points in the room. Even by moving the mic and inch.

Use this graph as your 'flat' baseline - then put the mic in your actual listening position. Record the actual room sound this time, and then match levels and look for big differences at specific frequencies.

[mamm7215]

You need to set the mic up where your head would be listening to your mixes. That will give you the room response where you're listening. I doubt you'll be mixing with your ear 4.5" away from one speaker...

[svart]

4.5 inches is too close to measure properly. You need to move back a couple of feet but then you'll get too much room interference.

[Ethan Winer]

Originally Posted by bluesj

I hold SLM 4.5inch away from the middle point between Hs80m tweeter and woofer for accuracy

At 4.5 inches away you're not getting much of the room, if any. The RS SPL meter falls off pretty substantially at high frequencies, but that big peak is either the speaker itself, or due to being so close to the tweeter. I'll guess it's the speaker as many speakers have an intentional HF boost to sound airy and pleasing.

You can see the raw response of typical RS meters here:

Comparison of Ten Measuring Microphones

--Ethan

[bluesj]

Originally Posted by Guitar Zero

Are you sure that's not the frequency response curve of the mic?

I set Radio shack SLM to C weighting

[bluesj]

Originally Posted by mamm7215

You need to set the mic up where your head would be listening to your mixes. That will give you the room response where you're listening. I doubt you'll be mixing with your ear 4.5" away from one speaker...

this is the result when I set the mic up where my head would be listening to my mixes
very horrible sounds . my room is untreated. and I played two speakers (L,R) when i captured this Frequency response of the speakers

[-Noodles-]

Interesting results..

What was the point of this,.. just for fun?

[Mike Brown]

Originally Posted by bluesj

my room is untreated at all

This will be a easy/cheap fix to improve your room DRAMATICALLY.

Check out the acoustics forum here and Ethan's website!

[Glenn Kuras]

Originally Posted by bluesj

this is the result when I set the mic up where my head would be listening to my mixes
very horrible sounds . my room is untreated at all

Wow that looks like a great case for bass trapping and reflection panels.

Glenn

[peat]

Originally Posted by bluesj

I set Radio shack SLM to C weighting

should stick with A-weighting
it is more suited to match a humans hearing response

b and c weighting have a more severe spectral bias more suited to measuring really loud sources

usually not used very much

when in doubt go with A-weighting

[Audiop]

Speakers are measured without weighing curves and speakers should measure more or less flat.


/Peter

[bluesj]

Originally Posted by bluesj

I used Emu 1616, Radio shack analog SLM and yamaha HS80m
when I mesaured the frequency response in my living room, I hold SLM 4.5inch away from the middle point between Hs80m tweeter and woofer for accuracy

this is for only one speaker...(not pair ,two)

I changed from Radioshack to Rode NT1. the graph is more flat... did i make a mistake?
unticked c weighting and cleared radioshack cal file...

[Audiop]

Why do you use weighing? That will give you false results if included in the graphs.

What kind of stimuli do you use? Noise? Sine sweep?

If you want to find out how the speakers measures you need to have a flat mic and use gating techniques to exclude the room (only works above 500Hz in typical setups).


/Peter

[elan]

Originally Posted by Audiop

gating techniques to exclude the room (only works above 500Hz in typical setups).


/Peter

what's a gating technique?

[AstralPStudios]

If you're trying to measure the room you'll want a ref mic or something
omni-directional. I can't remember if the NT1 is or not, I think it is...

Anyway, I always use pink noise, nothing else.

No weighting either, you'll skewer results.

[Ethan Winer]

Originally Posted by elan

what's a gating technique?

This is a big question and I'll give a short answer:

Measuring a loudspeaker in a room is always difficult because the room can have more affect on what is measured than the speaker itself. The ideal way to measure a speaker's response is in an anechoic chamber, where there are no reflections to create peaks and nulls. Another approach is to measure outdoors, ideally with the speaker on top of a flag pole.

Modern software uses a technique called "gating" that measures only for some number of milliseconds, then stops abruptly just before the first reflections arrive at the measuring microphone. In a large room like a gymnasium, with the speaker up on a ladder or otherwise suspended high up, the gate time can be set pretty long. In a small room you can measure for only a few milliseconds before reflections from the nearby surfaces collide with the direct sound and skew the results.

Bottom line: The longer the gate time, the lower in frequency the measurement is valid to.

--Ethan

[sham8723]

Flagpoles? Why spend time and effort eliminating a variable (the room) that will be present during the use of said speakers? I would say that the response in the room within the speakers will be used would be just the graph you would need unless you're the engineer measuring the response to put the model out on the market to various spaces. Why not measure the response, apply corrective room or response EQ if you deem it necessary and see how that works out for you?

[DAH]

Originally Posted by sham8723

Flagpoles? Why spend time and effort eliminating a variable (the room) that will be present during the use of said speakers? I would say that the response in the room within the speakers will be used would be just the graph you would need unless you're the engineer measuring the response to put the model out on the market to various spaces. Why not measure the response, apply corrective room or response EQ if you deem it necessary and see how that works out for you?

Because there^s NO "ROOM RESPONCE" as such... And u cant correct time domain issues by EQ.