Front firing vs. downward firing subwoofers

[DJ in TX]

So is one better or more efficient than the other?
And, does it change where you should place the sub? or is it all pretty much the same? It seems like downward firing would be more omnidirectional.

Thoughts?

 

[TLS Guy]

So is one better or more efficient than the other?
And, does it change where you should place the sub? or is it all pretty much the same? It seems like downward firing would be more omnidirectional.

Thoughts?

There is no directionality at sub frequencies.

 

[TLS Guy]

There is no directionality at sub frequencies.

Several points. Yes, a second order sub in receivers is suboptimal. However the db scale is log, so at 160 Hz 12 db down is significantly below average program and will likely be masked.

The next issue is you don't know what the driver roll off is. A lot of sub cones are big and heavy to get F3 down and a second order roll off of the driver above 100 Hz is common. So you could be actually 24 db down at 160 Hz.

The next issue is that Hollywood boost the lowest frequencies by as much as 20 db. So it is theoretically possible for your sound effect boom to be down as much as 44 db at 160 Hz, even with an 80 Hz second order crossover in the receiver.

 

[DJ in TX]

Several points. Yes, a second order sub in receivers is suboptimal. However the db scale is log, so at 160 Hz 12 db down is significantly below average program and will likely be masked.

The next issue is you don't know what the driver roll off is. A lot of sub cones are big and heavy to get F3 down and a second order roll off of the driver above 100 Hz is common. So you could be actually 24 db down at 160 Hz.

The next issue is that Hollywood boost the lowest frequencies by as much as 20 db. So it is theoretically possible for your sound effect boom to be down as much as 44 db at 160 Hz, even with an 80 Hz second order crossover in the receiver.

That was weird...all I could hear when reading your post was Charlie Brown's Parents. You know... "Wa wa wa...wa Wa wa wa."

Don't think I am taking issue with your opinion, as that would require comprehension. Even though I have enough posts to be categorized as "Audioholic", I assure you I am still very much a noob.

 

[gmichael]

That was weird...all I could hear when reading your post was Charlie Brown's Parents. You know... "Wa wa wa...wa Wa wa wa."

Don't think I am taking issue with your opinion, as that would require comprehension. Even though I have enough posts to be categorized as "Audioholic", I assure you I am still very much a noob.

They both go BOOM BOOM BOOM, about the same. The driver(s) and amp(s) used will make a bigger difference than front or down firing will.

 

[TLS Guy]

They both go BOOM BOOM BOOM, about the same. The driver(s) and amp(s) used will make a bigger difference than front or down firing will.

I think your post it pitched at the correct educational grade level.

By the way there was a post that got lost in the thread, this is the question I was replying to: -

Okay, maybe I can get you to clear something up for me.

I'm using a rec'r with a 12dB/octave crossover. So if there's a loud 'boom' in a movie that is say 100 dB (I need to make this part up because I don't know the real frequencies affected) my sub would be putting out a 160Hz sound at 88dB which is clearly localizable.

I have always been able to tell where my sub(s) are nearfield too.

 

[DJ in TX]

Sometimes I read the replies to my thread and am not sure if they were intended to be rude or funny. I suppose in this case it could go either way. Not a big deal I guess.

Thanks for the info...and the translation.

 

[gmichael]

I think your post it pitched at the correct educational grade level.

By the way there was a post that got lost in the thread, this is the question I was replying to: -

Okay, maybe I can get you to clear something up for me.

I'm using a rec'r with a 12dB/octave crossover. So if there's a loud 'boom' in a movie that is say 100 dB (I need to make this part up because I don't know the real frequencies affected) my sub would be putting out a 160Hz sound at 88dB which is clearly localizable.

I have always been able to tell where my sub(s) are nearfield too.

It's easy when I'm at the same level myself. I've just been arounf long enough to pick up a few things.

You seem to have more of a statement than a question. Am I to answer you or translate to basic speak?

I'll take my best shot. Without going through the math, your asumption of 160Hz after the 12db roll-off from 100 Hz seems correct. That would be why you can tell where your sub is located by ear. I have mine crossed over at 60Hz to prevent that. (most feel that 80 Hz is the way to go, but I like 60)

 

[gmichael]

Sometimes I read the replies to my thread and am not sure if they were intended to be rude or funny. I suppose in this case it could go either way. Not a big deal I guess.

Thanks for the info...and the translation.

I'm just a simple guy who has figured out how to translate Techno-babble into plain English. But I sure do like a good joke now and then. Keep your sarcasm detector on it's highest setting.

 

[JerryLove]

I'm using a rec'r with a 12dB/octave crossover. So if there's a loud 'boom' in a movie that is say 100 dB (I need to make this part up because I don't know the real frequencies affected) my sub would be putting out a 160Hz sound at 88dB which is clearly localizable.

I have always been able to tell where my sub(s) are nearfield too.

I think my sub-crossover is set around 90Hz. I seem to recall that being the default / THX standard, though it's variable (I'd rather the mains do all they can before crossing to the sub). Why do you have a crossover high enough that the sub is doing 160Hz at all?

 

[jamie2112]

There is no directionality at sub frequencies.

As a live sound engineer,there are many (steering) software programs to actually manipulate where you low end is going directionally.JBL EAW D&B have all spent millions of bucks making low end directional as far as live sound goes.HT is a whole nother ballgame of course.Just wanted to say that the low end directionality thing is a very hot topic in the Live audio world...

 

[Alex2507]

I think your post it pitched at the correct educational grade level.

By the way there was a post that got lost in the thread, this is the question I was replying to: -

Okay, maybe I can get you to clear something up for me.

I'm using a rec'r with a 12dB/octave crossover. So if there's a loud 'boom' in a movie that is say 100 dB (I need to make this part up because I don't know the real frequencies affected) my sub would be putting out a 160Hz sound at 88dB which is clearly localizable.

I have always been able to tell where my sub(s) are nearfield too.

Thank you for replying to my post, TLS. I deleted it because I thought it might be a bit of an off topic question and I didn't mean to confuse Jerry there.

Jerry, all the clues are there. You can put this together if you try real hard but it won't be worth it. My rec'r crosses at 80Hz.

DJ, stick around and the lingo will start to make sense.

 

[highfigh]

As a live sound engineer,there are many (steering) software programs to actually manipulate where you low end is going directionally.JBL EAW D&B have all spent millions of bucks making low end directional as far as live sound goes.HT is a whole nother ballgame of course.Just wanted to say that the low end directionality thing is a very hot topic in the Live audio world...

But live rigs usually have some kind of horn loaded arrangement in a large venue, right? That at least helps it to not all go behind the cabinets.

What is your usual lowest frequency for live gigs? Is anyone really dipping into the 20-30Hz range on a regular basis?

 

[jamie2112]

But live rigs usually have some kind of horn loaded arrangement in a large venue, right? That at least helps it to not all go behind the cabinets.

What is your usual lowest frequency for live gigs? Is anyone really dipping into the 20-30Hz range on a regular basis?

Yeah but just sayin.....
Most of the samples on live stuff go to 26hz but my band stuff is at 28 to 30 on most of the sampling.

 

[TLS Guy]

As a live sound engineer,there are many (steering) software programs to actually manipulate where you low end is going directionally.JBL EAW D&B have all spent millions of bucks making low end directional as far as live sound goes.HT is a whole nother ballgame of course.Just wanted to say that the low end directionality thing is a very hot topic in the Live audio world...

Yes but live gigs are in large venues where the room is many wavelengths long unlike domestic rooms that are shorter than the wavelengths involved generally. So yes, it is another ball game.

 

[jamie2112]

Yes but live gigs are in large venues where the room is many wavelengths long unlike domestic rooms that are shorter than the wavelengths involved generally. So yes, it is another ball game.

I know I know I was just winding the thread up.....sorry Doc just a windup my man.....

 

[TLS Guy]

I know I know I was just winding the thread up.....sorry Doc just a windup my man.....

Got it now!