ProSoundWeb Community
Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Subwoofer Forum => Topic started by: Mike Henderson on August 23, 2020, 12:47:36 PM
-
Hey guys, I had addressed this issue before but now there is a different twist on it so I am posting a new thread for it.
I am dealing with two local speaker install and setup guys here with two different opinions.
With my dual 18" Sonic bass reflex speaker, some tunes I can feel the bass at around 20' away from it but most tunes I will get that same effect like inside of 7'. So I asked both guys if it would be possible in any way to get every tune's bass at 20'
One guy is telling me I might be able to get the 20' if the "frequency" is set right. The other is saying nothing can be done as every tune is made with it's own SPL so who is correct please? I don't have the scientific technical knowledge of speakers which is why I am asking here.
-
Is that in the same venue with the equipment setup in the same place or across multiple different places? For low frequencies in particular the room has a hugh effect on where and how loud the bass is. And how much bass or kick drum a recording has is going to vary a lot too, some have it in spades and some not so much. IMO it's not your job to fix poor recordings but that is just my opinion.
-
In theory a multi-band dynamics device could do what you have in mind to a degree. If every song being input could have its own setting it would be more consistent, and lord knows how the room is affecting things?
Can SPL in speakers be controlled? The short answer is yes, the long answer is that a lot of work and processing is required to do what you have in mind though and that yes requires a fair amount of work. You are basically talking about having a threshold that you want to target and need the audio expanded up or compressed down to that threshold on a frequency range basis. This is a task that is not easily done with a set and forget devise and a random series of media. If you had a set playlist that you could doctor and tune the media for an optimal ( for your needs ) setting, then apply the expansion and compression afterwards to lock it in, I could see this being more viable.
If you have a 1950's era song that hasn't been heavilly modernized ( mastered to modern standards ) and then you have a modern song, the disparity in dynamic and sonic range between them will be very hard to even out with a basic and static set of tools. If you are playing nothing but stuff made in the past decade, you may have an easier time doing that. Even songs cut in the 1980's are far enough from today that the task will be hard.
-
Can SPL in speakers be controlled? The short answer is yes, the long answer is that a lot of work and processing is required to do what you have in mind though and that yes requires a fair amount of work. You are basically talking about having a threshold that you want to target and need the audio expanded up or compressed down to that threshold on a frequency range basis.
Yes you've nailed it. I get the part about the room acoustics . This is not my query but I understand it's role in this.
I think what's always be knowing at me is that the guy said he is able to get constant bass distance and power because of his Digital processor's settings but he had also said it was due to the speaker cab type he has and then too his application is having his speakers in his yard.
-
SPL can be "controlled". Want it louder? Put more power in there. Speakers melted? Get more/better/both speakers.
Want it louder at some frequencies but not others? Use EQ to put more power in at those frequencies, but not the others.
Generally, I've found that more LF extension (ie, a lower -3dB or -10dB point) directly translates as more low-frequency "feel", but as you go deeper into the bass, you need more swept volume (literally, the volume of air being moved) to keep the SPL up.
Chris
-
SPL can be "controlled". Want it louder? Put more power in there. Speakers melted? Get more/better/both speakers.
Want it louder at some frequencies but not others? Use EQ to put more power in at those frequencies, but not the others.
Generally, I've found that more LF extension (ie, a lower -3dB or -10dB point) directly translates as more low-frequency "feel", but as you go deeper into the bass, you need more swept volume (literally, the volume of air being moved) to keep the SPL up.
Chris
Hmnn, that is basically what he says too. He did say that to control the frequencies it can only be done with a digital processor rather than my Ashly XR1001 Analog crossover.
-
The quick answer is somewhere between "no" and "sort of".
Any broad correction applied will be present full time. Music that does not need "enhancement" will get it anyway and you'll be almost as unhappy with the results as having less low end in "legacy" recordings.
You have to fix these problems at the source - and if the LF info isn't there, you have few real-time tools to apply. Recordings mastered for vinyl pressings have vastly less LF content below 50Hz (especially as the groove gets closer to the center of the disc) because the stylus wouldn't stay in the groove without very high (damaging) tracking pressures. Because the master recordings do not have the LF info present, EQ is a minimally effective option.
I recommend something like the dbx 120/500 sub-harmonic synthesizer for those sources that lack LF. You will NOT be able to create, from thin air, anything like the +20dB 'haystack' in the sub region that exists in contemporary recordings but it will greatly help.
IOW, you installers are basically wrong. Both of them. And your old Ashly is just that - "legacy". I used several analog Ashly crossovers 30 years ago but 20 years ago moved to digital system processing/control and never looked back.
The idea that bass only travels a particular distance is also wrong. The LF info, if present, behaves the same way for a given place in the listening environment. Moving even a couple of feet in any direction will change your perception of the bass due to boundary reflections. You can't "eq" a reflection away.
-
Yes you've nailed it. I get the part about the room acoustics . This is not my query but I understand it's role in this.
I think what's always be knowing at me is that the guy said he is able to get constant bass distance and power because of his Digital processor's settings but he had also said it was due to the speaker cab type he has and then too his application is having his speakers in his yard.
"In his yard" and inside a room are VERY VERY different things when it comes to low end.
Here is a fun little test to show you how much difference a room plays upon the sound.
Go INSIDE a room. Use a SINGLE loudspeaker/sub Play a sine wave, it doesn't have to be loud, just a comfortable level. Say 80Hz. Walk around the room and listen (and make mental notes) about where the sound is loud and where it is almost gone.
Now play a different tone, but not a mulitple or sub multiple of the same freq. let's say 58Hz. Walk around again, and make the same mental notes of loud and quiet places. They will have moved.
There is NO processor that can fix this, except a bulldozer or wrecking ball. The ROOM is the dominate issue.
So different songs will have bass notes that are louder or quieter at different locations, ie distance.
Outside you don't have walls or ceilings. You cannot compare the two.
-
What it sounds like you are dealing with is uneven response from your speaker. Bass frequencies used in different songs may be different. If your speaker is resonating at certain frequencies, it could be 10+db hotter at those frequencies. This can be a combination of the speaker design, and placement within the room. In an ideal world, you do NOT want speakers to behave like that.
You can try and use EQs and processors to fix the mess, but sometimes they can only do so much. In this case, you could probably adjust to get rid of the peak, but that would decrease the bass of the songs that are misbehaving, not increase the response of the rest of the songs.
Once you get them all behaving the same, then you can simply increase the power of all the low end frequencies in general so that you have an equal response.
-
"In his yard" and inside a room are VERY VERY different things when it comes to low end.
Here is a fun little test to show you how much difference a room plays upon the sound.
Go INSIDE a room. Use a SINGLE loudspeaker/sub Play a sine wave, it doesn't have to be loud, just a comfortable level. Say 80Hz. Walk around the room and listen (and make mental notes) about where the sound is loud and where it is almost gone.
Now play a different tone, but not a mulitple or sub multiple of the same freq. let's say 58Hz. Walk around again, and make the same mental notes of loud and quiet places. They will have moved.
There is NO processor that can fix this, except a bulldozer or wrecking ball. The ROOM is the dominate issue.
So different songs will have bass notes that are louder or quieter at different locations, ie distance.
Outside you don't have walls or ceilings. You cannot compare the two.
^^this
I wanted to say exactly this when i first saw this thread but couldn't figure out a good clear way to say it. Ivan basically nailed it.