|
Post by Boomzilla on Jun 24, 2020 8:17:00 GMT -5
The idea has been proposed (Steve Guttenberg) that the best way to eliminate room effects with subwoofers is to place the subs in near-field, immediate proximity to the listening position. This idea would have much to recommend it on the face of it:
1. By having the sub in near-field placement, the relative loudness of the sub can be reduced exponentially - This reduces distortion significantly.
2. By having the sub in near-field placement, the room contributes far less to the bass that reaches the listener's ears. This allows the sub to run with a far flatter frequency response than would be possible if the sub were anywhere else in the room.
3. By having fewer room peaks and dips to equalize, the DSP can more easily correct the subs for flat response.
4. Because the bass amplitude will be far lower, room effects will be minimized (echoes will be far fainter at the lower sub volume).
5. Because the bass amplitude will be far lower, the subwoofer cabinet will vibrate far less and the bass will be cleaner.
Think of this setup as "bass headphones" for the system.
But to do this, wireless sub transmitters will be almost mandatory. Additionally, phasing between the main satellite speakers and the subs will become tricky, and the phase will have to be carefully adjusted for a smooth match. Further, the WAF for hulking black subs at both ends of the living room couch may be meager (putting it politely).
Has anyone tried this? How did it work out?
Thanks - Boomzilla
PS: One other question - With subwoofers placed near-field, will right and left channel bass information become independently audible? The common claim is that anything below 100 Hz. is non-directional, and with common room placements for subs, I can understand how that's likely true. But with near-field sub placement, it would seem that differential channel bass information might be better localized by the listeners ears. Yes or no?
|
|
|
Post by AudioHTIT on Jun 24, 2020 8:37:53 GMT -5
.. Think of this setup as "bass headphones" for the system. ... Ha, First thing I thought of when I started reading was ‘subphones’. Actually interesting idea for a very dedicated space built for limited seating. It still seems the Bass would propagate and the room would get involved, but maybe not as much at lower levels. I won’t be trying it but it seems to have merit as a concept.
|
|
|
Post by pedrocols on Jun 24, 2020 9:20:36 GMT -5
I do have my subwoofers rather closely (maybe 3 feet away) to my listening position. Mine don't allowed me too much freedom when it comes to placement. The spl and everything else is optimized for the listening position.
|
|
|
Post by ttocs on Jun 24, 2020 9:48:51 GMT -5
I would think the timing issue would be an advantage seeing that bass is "slower" to begin with. No? Yes?
This idea is something I've wanted to try, so maybe I will in a week or two once some minor renovation is finished.
|
|
|
Post by AudioHTIT on Jun 24, 2020 9:55:38 GMT -5
I would think the timing issue would be an advantage seeing that bass is "slower" to begin with. No? Yes?This idea is something I've wanted to try, so maybe I will in a week or two once some minor renovation is finished. Bass drivers might be slower because of their size, mass, and the volume of air they must move; though that’s a generalization and not necessarily true in every case. Low frequencies however travel at the same speed as other audible frequencies.
|
|
novisnick
EmoPhile
CEO Secret Monoblock Society
Posts: 27,235
|
Post by novisnick on Jun 24, 2020 10:15:08 GMT -5
I’ve been using near field subs for years now, one to my left side as an end table and one directly behind my chair. This position has worked very well for my situation. Two PSA 3000i subs, that’s two each of their 15” drivers! 😁❤️ It has eliminated any nodes at our seats and response is instantaneous. The sub amps are Duel ice modals that are rated at 1700watts, so they have plenty of power to move the cones quickly. I don’t use my subs for stereo as my main speakers provide plenty unless I’m listening to organ or want a lot more bass. I’d be happy to share my experiences with them if anybody has any questions. forums.audioholics.com/forums/threads/power-sound-audio-psa-s3000i-subwoofer-overview.94124/
|
|
|
Post by monkumonku on Jun 24, 2020 10:52:16 GMT -5
Seems that would greatly help with reducing room effects on the subs.
On the other hand, with the subs so close wouldn't that then make them seem directional? With movies that might be okay since you are meant to feel the impact of a blast or other deep bass moment on the screen, but for music it would make it seem like the bass player is next to you while the rest of the band is in front.
|
|
novisnick
EmoPhile
CEO Secret Monoblock Society
Posts: 27,235
|
Post by novisnick on Jun 24, 2020 11:04:47 GMT -5
Seems that would greatly help with reducing room effects on the subs. On the other hand, with the subs so close wouldn't that then make them seem directional? With movies that might be okay since you are meant to feel the impact of a blast or other deep bass moment on the screen, but for music it would make it seem like the bass player is next to you while the rest of the band is in front. Actually, it’s fine as long as you dial them in for stereo but that leaves a compromised HT experience. That’s not the end of the world if you have a pair of subs and use only one for stereo and both for HT. I’ve tried this and have gotten good results.
|
|
|
Post by gus4emo on Jun 24, 2020 11:22:55 GMT -5
Seems that would greatly help with reducing room effects on the subs. On the other hand, with the subs so close wouldn't that then make them seem directional? With movies that might be okay since you are meant to feel the impact of a blast or other deep bass moment on the screen, but for music it would make it seem like the bass player is next to you while the rest of the band is in front. Actually, it’s fine as long as you dial them in for stereo but that leaves a compromised HT experience. That’s not the end of the world if you have a pair of subs and use only one for stereo and both for HT. I’ve tried this and have gotten good results. That's what I do, and love it...
|
|
|
Post by Boomzilla on Jun 24, 2020 12:05:41 GMT -5
Seems that would greatly help with reducing room effects on the subs. On the other hand, with the subs so close wouldn't that then make them seem directional? With movies that might be okay since you are meant to feel the impact of a blast or other deep bass moment on the screen, but for music it would make it seem like the bass player is next to you while the rest of the band is in front. In fact, not necessarily. The "phase" dial on the sub plate amplifier introduces a variable delay. If the subs are closer to you (or farther from you) than the satellites, just adjust the phase until both wavefronts arrive at the ear simultaneously. Easy to adjust, too - just place a SPL meter (cell phone app is fine) and play pink noise continuously with the cell phone where the listener's head would be. Have one person watch the SPL while the other slowly alters the phase dial. At the point where the SPL is highest, the sub and satellites are in phase. If you want, you can also reverse the phase on the speakers - then when the SPL is lowest, the speakers and sub are matched (just remember to put the speakers back in phase afterward). If the sub and the satellites' sound is reaching you ear simultaneously, then no - you won't be able to tell where the bass is coming from. In fact, your ear will interpret it as if the whole spectrum was coming from the satellites.
|
|
|
Post by Jean Genie on Jun 24, 2020 12:36:48 GMT -5
This would certainly shorten your 'subwoofer crawl'!😂
|
|
|
Post by audiobill on Jun 24, 2020 20:07:57 GMT -5
Try “bass shakers” in your listening sofa or chair for no room interaction but visceral bass. really.
|
|
|
Post by Gary Cook on Jun 24, 2020 20:32:21 GMT -5
In the home office I have the sub under the long bench, about 6" from my out stretched toes. I guess that's "near field"? Works great, sounds good, with a 12" Soundstream driver in a dual (front) ported enclosure, so it doesn't need much amp power to agitate the socks and rattle the tibias. I have a couple of old blankets rolled up under the bench to help with the echo.
Cheers Gary
|
|
|
Post by Gary Cook on Jun 26, 2020 17:03:31 GMT -5
What I notice most about having the sub woofer very close is that it adds a lot to the overall sound which is more noticeable at lower volumes. In conjunction with the Airmotive4's I have found an 18 db slope at around 120 hz works really well for the late night / early morning sessions in the home office when volume is not at my usual listen levels. The 4's need a bit of volume to extend their range which is bit too loud and wakes the boss, with the sub added the sound is fuller and the WAF is much higher. Currently (7.00 am) listening to Michael Buble's It's Time at a decent listening volume without any complaints.
Cheers Gary
|
|