Axiom Home Page Forums General Discussion Technical Questions Axiom graphs

As Ian stated, Axiom does not use smoothing which prompted part of Ricks question.

I got that part Randy. What I don't understand is is the difference in how the anechoic chamber compares to them being done quasi-anechoic and to what affect the different db levels affect the graph being compared.

The main difference between the two is the anechoic chamber is built without any echoes and is not room influenced at all. Quasi-anechoic measurements are not accurate below the midrange where the room starts to dominate with this technique. So the amount of accurate information you can gather is more limited with the quasi-anechoic measurement.

Neither technique can measure low frequencies accurately. This is why subwoofers are measured outside.

Different db levels show at what SPL the frequency sweep occurs at. If there are deviations in the frequency response at increasing sweep levels it is a sign the speaker is stressing aka compression.

Thanks Doc. So can it be said a speakers measurement done quasi will not be considered to be measured as accurate as one done in an anechoic chamber?

If you look at measurements done quasi-anechoic, they never show the speaker below 200hz. On the other hand an anechoic chamber will give you accurate information below that. For a full range floorstander, the anechoic chamber will not accurately assess the bass response though.

Thanks for the correction Ian. My apologies for misstating the case.

I was looking at the old NRC measurements and did not take into account the difference in scale.

I do need to clean the troll crap off my shoes though. I've been wading through bad threads again.