This along with the other 15 videos from Dennis that I watched today are excellent. Just crazy excellent. => ID issues in your specific room and specific use. =>Treat with ACDA-10 first, =>Then ACDA-12 next and =>lastly Diffusion. I have many other videos to watch. Also, learned to not buy junk that uninformed folks sell. Address the issues with the correct treatment. Thank you for all of your educational videos Dennis.
I understand lower freq. radiate outwards in a circular pattern, through walls, etc. And opening doors to adjoining rooms will help to dissipate those long wavelengths too. So we treat with bass traps where it collects like walls and corners. I think that's how it works. Thanks.
@@AcousticFields the energy maximum is still in the corners while in the middle of the room there is none at all - so placing a trap in the middle of a standing wave gives you little to nothing
I have seen this many times while doing live sound and ringing out different rooms to compensate with EQ. The problem frequencies that feedback first are all multiples of the fundamental. You can see it on the eq when you are done. The cut frequencies will be 100, 200, 400, 800 and so on, or multiples of whatever fundamental is amplified by the room. I would very much like to work in a room that has a flat response.
start with a crossover of 60 Hz and a subwoofer only going down to 35 Hz combined with a subsonic filter - very few music has useful information below that
M, Processing is to be used as a polish not a solution. You need to treat double digit peaks and dips in frequency response using the proper room size and treatment to match usage and then use processing to polish up a +2- +3 dB issue.
@@AcousticFields Thanks for the reply. This makes sense, of course. Thanks for all your videos, they're really helpful, and I take everything on board. Much appreciated.
Question from DJ who never gets to play in treated rooms? If I reduce the 30 to 50 hz with eq will the harmonics still remain? Those low frequencies Can create havoc and booming in certain areas of a hall, say 1500 to 2000 square feet! And complaints!
If you treat a 30Hz room node with a pressure activated absorber, i can't see any reason why the harmonics of that fundamental would be affected in any way. The 30Hz node itself does not cause the 60Hz or 90Hz to occur. It's purely the distance between two opposing walls that are creating independant nodes.
O, A fundamental mode excites the harmonic and yes distance is in play. If you reduce the amplitude of say 40 Hz. you will have less peak issues to manage in most cases at 80,120 etc. Anytime you can impact one frequency range say 30 - 100 Hz. with proper rates and levels of absorption regardless of room size/volume., your treatment issues from 100 - 6,300 Hz. are much easier to deal with and usually require less treatment costs the less peaks one has in the response curve.
@@AcousticFields This is simply not true, and it is very easy to disprove. Play a tone that excites the rooms second harmonic and measure it with RTA. Introduce the fundamental tone, and you will find that the second harmonic does not change.
0, From a technical standpoint yes. However, fewer peaks below 100 Hz. make all other issues much easier to work with. Easier to identify and easier to treat. I am trying to show people that everything is related. There is no one specific cause for anything. Everything is dependent on everything else.
I think you are misunderstanding what he's saying…. When he says produces the harmonics, he's not referring to the room itself, he's referring to what is played in music and/or speech. If you play a low E on a bass guitar, that note is going to comprise of the fundamental at 41hz AND all of its relative harmonics.
@@Oneness100 These harmonics are created solely by the instrument, not the room. This phenomenon does not apply when it comes to room treatment for sound reproduction.
K, You have to go after the low-frequency fundamentals first and foremost. Managing the fundamental life cycle makes the middle and high frequency harmonics easier to deal with using treatment and single processing. Happy wife, happy life.
Your math is correct, but the way you explained it is wrong. Harmonics are not a simple doubling of frequency. It's the fundamental x the harmonic, so 1F, 2F, 3F and so on...
C, When you are trying to communicate a complex topic, it is best to start the process with simple processes such as linearity, to help a person have a foundation to build further knowledge upon. After you achieve a certain level of understanding, you can then polish up the rough edges.
This along with the other 15 videos from Dennis that I watched today are excellent. Just crazy excellent.
=> ID issues in your specific room and specific use. =>Treat with ACDA-10 first, =>Then ACDA-12 next and =>lastly Diffusion. I have many other videos to watch. Also, learned to not buy junk that uninformed folks sell. Address the issues with the correct treatment. Thank you for all of your educational videos Dennis.
I understand lower freq. radiate outwards in a circular pattern, through walls, etc. And opening doors to adjoining rooms will help to dissipate those long wavelengths too. So we treat with bass traps where it collects like walls and corners. I think that's how it works. Thanks.
J, Low frequency energy is trapped between two parallel walls not two parallel corners.
@@AcousticFields the energy maximum is still in the corners while in the middle of the room there is none at all - so placing a trap in the middle of a standing wave gives you little to nothing
Always a pleasure watching your videos Dennis. I think you could teach anything.
A, We appreciate your comments. Thank you.
i guess Im kinda off topic but does anybody know a good website to stream newly released series online ?
@Jase Zayden flixportal :)
@Leighton Marcellus Thank you, I signed up and it seems to work :) I appreciate it!
@Jase Zayden Happy to help xD
I have seen this many times while doing live sound and ringing out different rooms to compensate with EQ. The problem frequencies that feedback first are all multiples of the fundamental. You can see it on the eq when you are done. The cut frequencies will be 100, 200, 400, 800 and so on, or multiples of whatever fundamental is amplified by the room. I would very much like to work in a room that has a flat response.
D, Yes, that is the ultimate goal for all of us along with proper attack and decay rates.
It's a very good video! So it will be helpful. Thank you very much!🙏
You are welcome!
Is this for subwoofers or speakers?
start with a crossover of 60 Hz and a subwoofer only going down to 35 Hz combined with a subsonic filter - very few music has useful information below that
Crossing over frequencies is room dependent. There is no one size fits all.
These are helpful videos thanks Dennis!
Interesting..👍
Glad you think so!
Would you recommend DSP as a stop-gap until one is able to physically address this?
M, Processing is to be used as a polish not a solution. You need to treat double digit peaks and dips in frequency response using the proper room size and treatment to match usage and then use processing to polish up a +2- +3 dB issue.
@@AcousticFields Thanks for the reply. This makes sense, of course. Thanks for all your videos, they're really helpful, and I take everything on board. Much appreciated.
Question from DJ who never gets to play in treated rooms? If I reduce the 30 to 50 hz with eq will the harmonics still remain? Those low frequencies
Can create havoc and booming in certain areas of a hall, say 1500 to 2000 square feet! And complaints!
Reducing fundamentals will assist you in reducing harmonics. It will also provide more definition in the harmonics.
you can practically cut off 35 hz and below for most types of music
i physically even feel unwell when subsonic frequencies are in the room
If you treat a 30Hz room node with a pressure activated absorber, i can't see any reason why the harmonics of that fundamental would be affected in any way. The 30Hz node itself does not cause the 60Hz or 90Hz to occur. It's purely the distance between two opposing walls that are creating independant nodes.
O, A fundamental mode excites the harmonic and yes distance is in play. If you reduce the amplitude of say 40 Hz. you will have less peak issues to manage in most cases at 80,120 etc. Anytime you can impact one frequency range say 30 - 100 Hz. with proper rates and levels of absorption regardless of room size/volume., your treatment issues from 100 - 6,300 Hz. are much easier to deal with and usually require less treatment costs the less peaks one has in the response curve.
@@AcousticFields This is simply not true, and it is very easy to disprove. Play a tone that excites the rooms second harmonic and measure it with RTA. Introduce the fundamental tone, and you will find that the second harmonic does not change.
0, From a technical standpoint yes. However, fewer peaks below 100 Hz. make all other issues much easier to work with. Easier to identify and easier to treat. I am trying to show people that everything is related. There is no one specific cause for anything. Everything is dependent on everything else.
I think you are misunderstanding what he's saying…. When he says produces the harmonics, he's not referring to the room itself, he's referring to what is played in music and/or speech. If you play a low E on a bass guitar, that note is going to comprise of the fundamental at 41hz AND all of its relative harmonics.
@@Oneness100 These harmonics are created solely by the instrument, not the room. This phenomenon does not apply when it comes to room treatment for sound reproduction.
Very cool tutorial 😎
S, Thank you for your comment. We all appreciate it.
@@AcousticFields your welcome, I've learnt a lot from your tutorials, I've been applying to my home theatre 11.2 sound system.
thanks
Cant thank you enough, Dennis! I've been learning more from you than in College lol! Greetings from Brazil
Ib, Thank you for your support.
Nice
A, Thank you. We all appreciate your comment.
@@AcousticFieldsI love acoustics, study it and here in italy there are not a lot of references so I usually learn watching your video
Good
yea
K, You have to go after the low-frequency fundamentals first and foremost. Managing the fundamental life cycle makes the middle and high frequency harmonics easier to deal with using treatment and single processing. Happy wife, happy life.
Please tell me where is the good place to keep my sub woofer
K, What is room size / usage?
Great
M, What is the first harmonic of 40 Hz.? What is second order harmonic of 40 Hz.?
The first harmonic of 40 Hz = 2•40Hz = 80Hz.
Second order harmonic of 40 Hz = 3•40Hz = 120Hz.
Your math is correct, but the way you explained it is wrong. Harmonics are not a simple doubling of frequency. It's the fundamental x the harmonic, so 1F, 2F, 3F and so on...
C, When you are trying to communicate a complex topic, it is best to start the process with simple processes such as linearity, to help a person have a foundation to build further knowledge upon. After you achieve a certain level of understanding, you can then polish up the rough edges.
💪💪🙏
Thank you for your support.
So how do we reduce the harmonics though?
J, The most cost effective way is acoustic foam using thicknesses beginning at 2" and going through 4".