What are the differences of a downward firing sub as opposed to a "forward" firing. Say for example SVS's PB1-ISD vs. Pinnacle's Baby Boomer? I am looking at placing the sub in the corner of the room between & behind the seating area. I'm getting mixed reviews and info on these two types of subs based on my placement choice. Some people are telling me that since LFE is non-directional then the "forward" firing style sub is the way I need to go because the downward firing sub will end up boomy in a corner. Others are telling me just the opposite.

Mike

What about forward firing driver with downward firing port?

I've seen, heard, designed and built, owned, and own all types of subs and have never been able to distinguish between them based on driver or port location.

Jeff Mackwood

I think your biggest concern is the crossover frequency. If it's higher, then you'll be able to localize the sound and therefore the downfiring might be better (assuming all else is the same). Other than that, I don't see much of a difference.

Having said that, who came up with this idea that bass under 50hz is not able to be localized by the human ear? I tell you decidedly I can localize the sound. Using test tones below 50hz I most decidedly am able to localize the sub. The 'optimum' placement for the sub in my room is behind and to the right of my listening location. But I can't stand it there. I can hear the sound behind me, and I don't like it at all. My subwoofer is crossed over at 40hz and is really there just because I like bass. But I swear I can tell exactly where it is at all times.

Embries, I use to have the exact same opinion, and I still do with most subs I've heard. I now own an SVS sub and have it crossed over at 80, and I no longer can localize it. I'm not sure if its the design or the combo of design and location. But when I hooked up my old sub and kept the crossover the same I could localize it again. Arizona Mike, don't know what to tell you since I have owned both, except what I just posted. Keep in mind that the SVS is not a small sub and cannot be hid easily. However, the SVS is designed for the corner of the room and is not boomy.

Today was slow at work, so I went on a little 'testing excursion' I took several subs we had on display into one of our sound rooms, and played the 'detectable/indetectable' game. I've come to the conclusion that the downfiring is better for stealth than the front/side/any other combo. Mind you, this conclusion is not based on any scientific findings, and as always I could be full of hogwash. I find, however, that the downfiring configurations tend to disperse the sound more evenly over the soundfield, which apparently is the key. I assume Wednesday this week will be slow at work again (since everyone knows to wait 'till the day after Thanksgiving to go shopping) so I think Wednesday I'll take some of the front firing woofers that were particularly poor in location performance, and attempt to put them on their side to proove my theory. Perhaps I'll get better performance, and that will be enough for me.

Just to put in my 2 cents, IMHO I think the best way to stop the localization effect is to run 2 or more subs. Under almost any room layout 2 subs just makes a vast improvement. With a 2 sub setup front or bottom firing should not make a difference.

Hope this helps

Lasher

Could you be localizing based on the distortion components? Alot of theses subs have 5% distortion, which would generate some harmonics that could be localized. Here I could see a downward firing sub might help as the higher frequencies would be more likely to be absorbed/scattered.

A thought: a corner has three surfaces, one of which is the floor. A floor-firing sub will (almost) always face a surface. A side-firing sub may be 'aimed' at a surface or away from the surfaces, if you find that such aiming makes a difference in your situation. Does that make a side-firing sub more flexible in its application?

Also, I'm in agreement that if your budget can handle it, two subs are an advantage.

i would disagree that two subs are better, one that is 2x as much is going to be better than two for the same price. low frequency sounds are not able to be pinpointed direction wise (assuming correct setup). i have one great sub and i cant tell where it is, when i turn it up i can tell a difference where it is only because of the heavier vibrations on things beside it compared to less across the room. if i had my way (which i dont) id get rid of all the other crap we have in the room anyway :-).

.

I wrote this about stereo subwoofers awhle back. Here is the link for those who have not read it. The nice thing about the setup suggested is that is costs little or nothing to try.

http://ubb.outlawaudio.com/ubb/Forum4/HTML/000250.html

WOW...there is a LOT of good info in that thread!

I just wanted to add, regarding the original question of this thread, that there is a school of thought that reads something like this:

A direct radiating (front firing) sub has the advantage of delivering it's output to the listener's ear BEFORE any and all reflected info, whereas a down firing sub can only deliver reflected bass info.

I'm not saying either method is better, but I do recognize it as a simple truth. I also think it may add to the direcionality of a sub vs. a downfiring sub...anyone have thoughts/facts on this? It may help Mike, and I think it's at the center of his original question.

Regarding 2 subs and the 6 dB advantage, I still contend that having a discrete LFE sub system and a RB sub will more than offset that advantage by not asking either sub to reproduce the brutal Dolby LFE+10+RB from 5 channels, summed mono bass signal.

SH: I've just finished connecting 2 subs plus 1 LFE sub as follows:

6 CH BYPASS, analog BM switched 'OFF'

SW output from the player to the LFE sub system (so no LFE ever enters the 950)

SW output from the 950 left empty.

FL from 950 to channel 1 of the Rane AC23B crossover and FR from 950 to channel 2.

Channel 1 LF output to sub #1, channel 2 LF output to sub #2

Channel 1 HF output to FL, channel 2 HF output to FR.

Crossover set at 80 Hz for Ch 1 & 2.

Subs are perfectly equidistant, and painstakingly phase aligned.

LFE sub is easily muted and/or volume adjusted on-the-fly, while the stereo subs are LFE signal-free.

I listened a bit last night to Diana Krall's MC SACD 'When I Look Into Your Eyes'. Though I can't know the method of mic configuration used, I am sure it's a mic'ed upright bass and I'm equally sure there is little, if any, of the bass in the other 3 channels.

MAN, I gotta tell ya...the dude was in my room playin' bass!! Again, with this particular disc, there's no way to know if it's a dual mono signal in each of the FL/FR channels or a true stereo mic'ed affair, but the effect is instantly noticeable.

Adding a touch of LFE in the third sub actually adds to the sense of a truly live sound.

Maybe it's this or that...I don't know, but I intend to manually graph the differences in FR, phase adjustment, filter slope, placement, etc., between a single, conventionally BM'd sub and this setup, as well as trying different source material that I know is stereo mic'ed (I have friends in the biz who will burn anything I ask them to...maybe I'll even lay down the bass lines for an experiment where I positively know what it SHOULD sound like.

In any case, very cool stuff! Thanx again for all your help.

here is a scientific article related to subs:
there are also other parts pertaining to different things..
www.harman.com/wp/pdf/Loudspeakers&RoomsPt3.pdf

Bosso:

The organ CD I circulated recently (and which is still circulating) was recorded with three spaced (30 feet, far left to far right) omni-directional condenser mikes, and I KNOW it has a lot of random phase bass both from the mic pickup technique and that which reverberates through the huge stone church where the recording was made. If you don't have it, you might try to get on the list.

http://ubb.outlawaudio.com/ubb/Forum6/HTML/000289.html


[This message has been edited by soundhound (edited December 03, 2003).]