Axiom Home Page Forums General Discussion Home Theater Subwoofers - Question

I just joined the Axiom "family" and need some advice. I am not an audiophile but just purchased M3's and a VP100 to start my H/T system (man, they are awesome!) and am now looking for a decent subwoofer. Is there any significant difference between a down-firing sub vs. a front-firing one? My system will be used 80% for movies and 20% for music, and the music will primarily be jazz-related. Any advice is welcome to help me in my search. Thanks.

Looks like all the "pro's" are too busy listening to their systems - or out Christmas shopping for more goodies to reply!! I'm relatively new to all this, but I can tell you from past recent listening experience, and from my own modest purchases...if you have more space than approximately 1500 cu. ft.(or a 12X15 room with 8 ft. ceilings), then you'd better opt for Axiom's EP175. I am getting by with my EP125 (combined with M3's, QS2's and a VP100), but find that I am setting the volume control on the EP125 up to 3/4 to get the desired "sub" effect, especially for movies. And this is with hardwood flooring and minimal drapery, etc. Hope this has been of some help!

Down firing subs attempt to amplify the sound by bouncing it off the floor while direct subs attempt to produce enough sound on their own. Listen to the two and determine what you like better. The direct firing sub should be tighter and more accurate in most situations, but you may like the boom of the down firing models better. That's the good and bad part of this hobby, everyone has different tastes. I suggest you audition both and see what you like.

I agree with Semi.
The difference b/w down firing and direct may produce somewhat different sound but since low Hz sounds have such a long wavelength they are considered non-directional. I certainly have not read of any reports or reviews where one is better than the other.
I've heard both and i like both. Do some auditioning at your local stores and hear it for yourself.

This one will be completely based on your taste. I have read in other forums about people who returned their down firing subs and swore that they will always stick to direct firing ones because they sound smoother. There are also those who absolutely love their down firing subs.

I have heard both and I prefer the direct firing. IMHO it sounds better in music.

Hi Jamm,

A general comment on subwoofer "sound": The qualitative nature of the bass you hear from a given design of subwoofer will be determined largely by the position of the subwoofer in the room, the way it couples to the room (and the resulting standing waves that are dictated by the dimensions and shape of the particular room), and by your location in the room relative to the subwoofer's position rather than by the particular way in which the sub generates those long deep bass wavelengths.

Thanks for your comment, semi_on, but a down-firing sub doesn't "amplify" the sound by bouncing it off the floor. All subwoofers couple to the floor on which they sit (it's the nearest surface) whether or not the energy emerges from a front-firing driver, a down-firing driver plus a port, a side-firing driver, or a port alone (a bandpass design where the driver is inside the enclosure, venting its energy to the room through only a port).

It's almost impossible to do controlled testing of subwoofers because of the way each interacts with the room and its position in the room. Every time I've evaluated different subs, it's been a change in the sub's position that radically changes the sound quality, not a different brand or type of design, assuming each sub has roughly the same woofer and enclosure size, and similar deep-bass extension.

Regards,

In reply to:

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Thanks for your comment, semi_on, but a down-firing sub doesn't "amplify" the sound by bouncing it off the floor. All subwoofers couple to the floor on which they sit (it's the nearest surface) whether or not the energy emerges from a front-firing driver, a down-firing driver plus a port, a side-firing driver, or a port alone (a bandpass design where the driver is inside the enclosure, venting its energy to the room through only a port).

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Thanks for the correction. What then is the functional difference between the sound that comes from a direct firing sub and a down firing sub?

They've always seemed a bit boomier to me.

> Thanks for the correction. What then is the functional
> difference between the sound that comes from a direct
> firing sub and a down firing sub?
>
> They've always seemed a bit boomier to me.

With the two different subs placed in the same place in the room, or with the sub put in the best place in the room for it? I think Alan was trying to say that you may have to put a down firing sub in a different spot in the room to make it sound right, compared to the proper place for a front firing one.

Michael

Joshua, my thought is that, other factors being held constant, there is no significant functional difference. If a sub driver is suitable for firing downward(i.e. it can withstand the "sag" involved in that positioning)and if the enclosure size, port tuning, etc. are the same, then it should be essentially identical regardless of orientation. The fact that the center of the driver is a few inches closer to the floor when firing down shouldn't lead to it being "boomier"; as long as it's within about 1/8th wavelength(say 20 inches)of the floor and both walls the bass will be adequately supported in either orientation.

I did a quick Google search to find something worthwhile on this and think sonicdesign.se/subplace.html covers it pretty well, despite a somewhat awkward translation from the Swedish.

Alan: I have a bi-polar sub one driver firing left and one firing right. No port holes. I thought the sub creates these waves by moving air through the ports. Hows does the bipolar design work without a port hole to move air.