What frequencies are "broadband"?

[RecordingMaster]

Hi there,

I'll probably die of embarrassment after writing this , but whatever...can't be scared to admit what I don't know!

My Google must be "broken" because I can't seem to find anything that explains what a broadband wave is specifically. Like what is the frequency range and what problems does it cause? Eg: how to identify the issue with our EARS?

The reason I ask is, when absorption comes into play I know that high frequencies are the least of our worries and the easiest to fix. Issues caused by high frequencies that we want gone are described as flutter echoes and too much high-pitched reverb/resonance/echoes. Easily fixed with a little foam or some foam diy panels.

When it comes to "bass" frequencies, I know these are the hardest to fix and the biggest problem in any room. So we need to apply bass trapping in the corners and such. Issues caused by bass frequencies that we want gone/trapped are described as too much bass build up in the room and too "boomy" or muddy and unclear bass tones.

So, that being said, where does broadband fit in? What issues does broadband cause (without using a special tool)? As in what problem issues caused by broadband waves do our ears and mics hear? And what is a broadband trap versus a bass trap? I know most studio foam is good for mid-high frequencies, so why a broadband trap if I have bass trapping and some practical use of mid-high dampening with foam?

Hopefully my question is valid...I feel it is.

 

[Massive Master]

Generally speaking, "Bass Trap" usually refers to an absorber tuned to a specific frequency (a room with a 140Hz peak might want a bass trap that's specifically tuned to 140/70Hz, etc.). Though the term "bass trap" can certainly be found in sentences with "broadband trap" and not cause too much confusion...

When we speak of broadband traps, we're generally referring to - you know - a broad band of frequencies. But still, usually the low end and lower midrange - which is what we're generally trying to absorb.

I'm not a physicist -- But I'd imagine ten or twenty pounds of absorbent mass (foam in this case), spread out, could probably absorb nearly all of the reflected 10kHz in a room. It would take hundreds and hundreds of pounds of mass (broadband panels, rigid fiberglass, tuned membranes, etc., etc.) to absorb nearly all of the 100Hz. The amount of energy goes up exponentially as the frequency goes down. It takes boatloads of broadband trapping to absorb the problematic low end without robbing the space of a "pleasant liveliness" (for lack of a better term).

What issues does it cause...? It's impossible to hear what the speakers are doing when that energy is resonating in the room. Frequency-specific peaks of 10dB or more - Cancellation (null points) of 30-40dB - best of luck working through that...

 

[RecordingMaster]

Generally speaking, "Bass Trap" usually refers to an absorber tuned to a specific frequency (a room with a 140Hz peak might want a bass trap that's specifically tuned to 140/70Hz, etc.). Though the term "bass trap" can certainly be found in sentences with "broadband trap" and not cause too much confusion...

When we speak of broadband traps, we're generally referring to - you know - a broad band of frequencies. But still, usually the low end and lower midrange - which is what we're generally trying to absorb.

I'm not a physicist -- But I'd imagine ten or twenty pounds of absorbent mass (foam in this case), spread out, could probably absorb nearly all of the reflected 10kHz in a room. It would take hundreds and hundreds of pounds of mass (broadband panels, rigid fiberglass, tuned membranes, etc., etc.) to absorb nearly all of the 100Hz. The amount of energy goes up exponentially as the frequency goes down. It takes boatloads of broadband trapping to absorb the problematic low end without robbing the space of a "pleasant liveliness" (for lack of a better term).

What issues does it cause...? It's impossible to hear what the speakers are doing when that energy is resonating in the room. Frequency-specific peaks of 10dB or more - Cancellation (null points) of 30-40dB - best of luck working through that...

Thanks Massive. Very informative. So let's put tuning aside and look at it from a caveman approach. If the room is too bassy/boomy (which it mostly always will be) put up some bass traps. For the rest of the frequencies, or at least a broader range of them, use broadband traps. For high frequencies, use foam?

 

[Massive Master]

To some extent, yes. But I've never been in a room with sufficient broadband trapping that required any foam (save maybe a sheet for a problem spot for whatever reason). Typical broadband traps do very well at 'softening' high end reflection without actually sucking the life out of the room.

I have the equivalent of around 36 (if they were 2'x4'x4") broadband traps in this room. It's not "dead" by any means. It's very controlled - No doubt - but it's "lively" enough to be "real" (for lack of better terminology).

Take care of the low end and there probably won't be enough of an issue with the high end to be worth going after.

 

[RecordingMaster]

To some extent, yes. But I've never been in a room with sufficient broadband trapping that required any foam (save maybe a sheet for a problem spot for whatever reason). Typical broadband traps do very well at 'softening' high end reflection without actually sucking the life out of the room.

I have the equivalent of around 36 (if they were 2'x4'x4") broadband traps in this room. It's not "dead" by any means. It's very controlled - No doubt - but it's "lively" enough to be "real" (for lack of better terminology).

Take care of the low end and there probably won't be enough of an issue with the high end to be worth going after.

Well I guess my question has been answered: a broadband trap is not to trap "broadband waves" but to trap A BROAD BAND of frequencies.

Yeah, my room's under control with bass trapping in corners and 2x4 3" foam panels I made and wrapped a while ago. So it wasn't so much a problem I was personally trying to solve, but rather curiosity and getting prepared for my next studio vision. I'll be moving in the next 6 months or so and I'm just thinking of what types of treatment I will have in my next house. It will help in choosing the right house with the right basement or finished garage.

Thanks!