SPL vs Frequency Graphs

3db

3db

Audioholic Slumlord
too add to the confusion I'm thinking that..

Acoustics do affect all frequencies but in different ways. With the high end you are correct the waves will reflect off walls and can cause a "harsh" sound or muddy the sound up, but this is not the same as what happens with lower frequencies. When one hears muddied dialog or a harsh sound this is from the same signal produced by a loud speaker hitting various reflection points then being reflected towards one ears at slightly different time. The brain has trouble separating all the information and it becomes muddied.

Swed mentions the low end where room nodes (specifically how sound waves interact with a given room) play more a role in completely canceling the waves out or making them double up on themselves.

The reason different frequencies respond differently to rooms is caused by wavelength.

Again if I made any errors someone please make me aware. I have been reading up much more on the technical side to this hobby but might have misunderstood something in the journals/books I have picked up.



Depending how everything goes I might, but there is no sense in making a new thread or hiding the real point of this thread midway through. I probably will end up doing it either way though. Maybe I'll just ask a mod to move it once I have made the changes :).

The wavelength of bass relative to the rest of teh frequency is very long and if you somehow make the wavelengths visible in a room, you would see nulls, +ve and -ve peaks and everything in between exactly like a sine wave. Thats why we all put the subwoofer at the listening position and crawl around the room on our hands and knees looking for the loudest and most even response. Thats probablly near a peak, positive or negative relative to the seating position. I don't know if this is classified as a reflection. I'm thinking its more related to finding the peaks in a wave length. But here is where I get confused. Boundary affects; placing a sub in a corner gives a stronger base response than along a wall. But having moved my sub around, I found the sweet spot about 2ft behind the seating position whcih is not close to any corner.
 
agarwalro

agarwalro

Audioholic Ninja
Absolutely fantastic thread. This one should be make a sticky...

Thanks to all who contributed.
 
avaserfi

avaserfi

Audioholic Ninja
Absolutely fantastic thread. This one should be make a sticky...

Thanks to all who contributed.
I am very glad many are appreciating this thread. Hopefully the OP will be edited soon to reflect the new additions :). I think the newer version is more substantial and takes into account Swerd's comments.

If anyone has suggestions for another similar write up on a different topic please PM me as I am willing to do more especially after seeing the positive reactions to this one. Right now I am leaning towards the importance timbrel characteristics and matching them during speaker selection as many people seem to think any 3 speakers will work as fronts/center together well. It just seems to be a last thought of many beginners.
 
avaserfi

avaserfi

Audioholic Ninja
I am very glad many are appreciating this thread. Hopefully the OP will be edited soon to reflect the new additions :). I think the newer version is more substantial and takes into account Swerd's comments.

If anyone has suggestions for another similar write up on a different topic please PM me as I am willing to do more especially after seeing the positive reactions to this one. Right now I am leaning towards the importance timbrel characteristics and matching them during speaker selection as many people seem to think any 3 speakers will work as fronts/center together well. It just seems to be a last thought of many beginners.
The thread has been updated guys. This is a more inclusive version of the original with a bit more depth in certain areas. Hope you enjoy and feel free to PM me with comments/suggestions for future ideas!

Ohh and it got a sticky :cool:.
 
annunaki

annunaki

Moderator
You're Welcome! :) This should help out in answering some questions for newcomers with questions.
 
no. 5

no. 5

Audioholic Field Marshall
I'm just being pedantic in pointing this out, but as for changes in loudness, it's a 6 to 10 dB change that is considered half or double loudness (depending on who you ask), and smallest detectable change in loudness varies frequency; around 3dB for 1kHz, but around 9dB for 35Hz, but that may be going far beyond the simple straightforward nature of the OP. :D
 
avaserfi

avaserfi

Audioholic Ninja
I'm just being pedantic in pointing this out, but as for changes in loudness, it's a 6 to 10 dB change that is considered half or double loudness (depending on who you ask), and smallest detectable change in loudness varies frequency; around 3dB for 1kHz, but around 9dB for 35Hz, but that may be going far beyond the simple straightforward nature of the OP. :D
Thanks for that. I fixed some parts but didn't think to proof it because I could never make a mistake :rolleyes:.

Just had the final, hopefully, update to this made. So it should be accurate and informative. Hope everyone enjoys and learns from it! I love the feedback so when I do it again I can do a better job.

Thanks to everyone who has replied.
 
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