Delay and phase in reference to a subwoofer are the same thing. Delay in this instance is the more accurate description of what the control is performing.
You have an unconventional listening space which may require an unconventional solution. Try what ever you can think of and see what happens. Aim your subs in different directions, Raise them off the floor, Raise them off the floor at different heights to each other, change the low pass filter setting (crossover point). There could be some cancelation caused by the interaction with the woofer in your mains. Try asymmetrical crossover points. If your speakers have ports try plugging and unplugging in various combinations. I'm sure there are other things you can try all you can do is see what happens.
In my system in a 14 x 10 x 9 room I have one sub sitting right next to the listening position aimed towards the main speakers and another sub almost directly behind that sub and aimed 90 degrees from it.
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I wonder if diffusers behind my speakers would help? In addition to bass traps. Because I can't pull my speakers out further than a foot off the front wall.
Lets say the diffusers, and traps and everything killed all the reflective problems, you have, what do you have left?
Only what's coming from the baffle face, even the back side of a dipole would be killed.
So taking what MC said the wave lengths and killing the rest, you can only do a few things. Make a little bass everywhere, very even, very controlled, but everywhere. That's out, can't clutter the floor.
or You could EQ the bass, why? Your killing the reflective excess, so you can increase the actual bass in the seated position. BUT you can't kill all the reflective surfaces, so that's kinds out.
But the bass comes after the mids, and the tweets before the mids, so what do you do? You HAVE to move the speakers. NOT I can only move them this much, there is no other option. If you want to fix the problem..
The bass needs to be closer to you, the mids and highs need to be further away. TIMING.... they (lows mids and highs) need to arrive at your ears, at the same time.
Regards |
@erik_squires: I only have a delay knob on my subs (PSA V1800). Is that what I should play with? I don't have polarity or phase controls. @millercarbon Oh wow different subs? I thought I wouldn't be able to do that. Which subs do you have. Do you find they give you clean bass with your speakers and are fast enough to keep up? Here are measurements during each sub off and then both on from the listening position: www.diabolicaldesign.net/subs.jpg |
Miller so in a smaller room you cannot get good bass without subs ? Correct. And small means small relative to wavelength. Since the the wavelengths of the lowest bass we want are 40 to 50 feet or more (depends how low you want to go) then small is anything less than that. Which means pretty much every room in every house is small. Look, its pure physics. Even at much shorter wavelengths we have to be clever with speaker placement and use things like diffusers and absorbers to get a nice smooth response. Exactly the same is true of bass, only the methods used have to be physically bigger on account of the physically longer wave lengths involved. Notice when you go to a concert in a large dome or hall the bass is wonderfully deep and uniform no matter where you go in the hall. That's because these spaces are large even relative to low bass waves. The waves have room to run and so when they do reflect off the walls its in different directions and times relative to the wave. In a normal room, say 20 ft, the leading edge of the wave bounces off the floor, ceiling, and all four walls even before one complete cycle! The darn thing is coming back and canceling itself sometimes right at the woofer! Think about it. But the flip side is if you take all this into account and do it right then you can actually have really fantastic bass even in a small room. You just have to abandon the old false paradigm of one or two subs and embrace the physical realities of long waves and use lots of subs. Because there's lots of subs they don't have to be big and powerful. Four or five ten inch subs is way better than one 20" even if the one is ten times as powerful. Because the one will create one powerful set of room modes. Bass will be thunderous but only at certain locations and frequencies. You will fight and struggle to tame this lumpy boomy awful bass. Which will not even go that low, by the way. But the four small subs will create four times as many different modes, each much smaller, so the bass will be smooth, powerful, and go really deep. DBA subs don't even have to match. Mine are a combination of three different subs. The bass is to die for. https://systems.audiogon.com/systems/8367 |
See the null ~ 120 Hz ? Makes me wonder if your speaker/sub polarity is not backwards. Flip and re-run.
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Thanks guys. Interesting anecdote about the speaker flip thing, heh. Anyway I did some measurements. Both with subs, no subs and at my listening position and at a position that is 3 feet back and 3 feet from the left wall. www.diabolicaldesign.net/Measure.jpgPlease have a look |
Most speakers don't provide that 'room lock' bass in my room that I hear in shop demos. I can't explain why but I had a pair of speakers on stands I couldn't get any bass from so due to the insanity of this hobby I flipped the stands over, mounted them to the ceiling than mounted the speakers to that and GOT the best bass ever! Why when the speakers were the same distance off the floor as they were off the ceiling and the same distance from the corners did it make such a huge difference? IDK, but it was embarrassing when visitors would bump their heads on them walking by. lol.
Often the best sounding systems by dealers have the speakers in the most unconventional places and if you don't have the freedom to place them where they sound best you're stuck with bass traps and digital eq along with your sub(s). Nice speakers, seriously wanted to give them a try. |
...so in a smaller room you cannot get good bass without subs ? Yes you can but you have to work harder at achieving the goal. Your room width is the same as mine and about 3 feet less in length than mine so I know it can be done. To start, get at least one if not both subs out of the corner. A couple folks posted links to videos that show you how to place subs using the crawl method. Try it out, you might be surprised. I use the method referenced by Atmasphere, but you can accomplish this with 2 subs as well, and they don't have to be big subs. |
Miller so in a smaller room you cannot get good bass without subs ? |
Diffusers work based on wavelength. That's why you see those panels with wood blocks of different sizes at different heights. Each frequency has a wavelength. The higher the frequency the shorter the wavelength. Little blocks of wood can diffuse high treble because the wavelengths are on the order of inches. The low bass you're concerned with is at a wavelength on the order of some tens of feet. Ten to forty or more feet. In order to work your diffuser needs to be at least that big. This is why we have the low bass problem in the first place: even an entire room is small compared to low bass waves!
This is also why bass traps are no solution. They can do something, just not much. The only real solution is a room that is multiples of the lowest bass frequency. A room a hundred or more feet on a side. Think about the phenomenally good bass you have experienced at a rock concert. Because: big room! The next best solution is lots of subs. Each sub still has the same mode problem. But with so many each one puts out less bass, so its mode is small, they are in different places, and together they average out to exceptionally smooth powerful bass.
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I wonder if diffusers behind my speakers would help? In addition to bass traps. Because I can't pull my speakers out further than a foot off the front wall.
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Guys thanks for all the feedback!
I forgot to mention my speakers are Yamaha NS5000 and they are about 1 foot off the wall. As for the separation I know its not ideal but i just don't have much space because I have a door to the left of my left channel and my sub to the right of the right channel.
My right sub is at the front right corner. My left is at the back left corner. Both firing down the long axis. I guess if I had 4 smaller subs I might get a better response than 2 subs. I don't have a ton of space to move my subs around because of other items in the room.
Would changing the firing direction of the subs make a difference since bass waves below 80 as you said are non-directional. I might be able to move one of my subs to a position where it is to the right of the listening position firing at the center of the room. I can't really do a crawl again because of so many other things in my room (it is a bedroom).
And I guess I am kind of stuck with the bass without subs because to fix it there I would have to I am guessing pull my speakers out further which I can't do right now.
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Move you listening position closer to a wall boundary. You may need to be anywhere from inches to 2-3 feet from the wall.
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Lots of bass at walls, lack of bass in center of room/listening position @smodtactical This is the classic description of a standing wave in the room. While room treatment will help a little bit, its effect is marginal. You have two solutions both of which will work fine, depending on how you want to handle this. The first is as others have suggested, move your subs around until you find a location that allows you to hear bass at the listening position. This can be tricky but can be done even with only one sub. Now if you think you might want to hear the bass properly in any position in the room, then you need to break up the standing waves. The only way to do that (you can't do it with room treatment) is to use multiple subwoofers. You'll need at least 4 to do the job. This type of subwoofer approach is called a 'Distributed Bass Array' and is very effective- with the qualification that none of the subs operate above 80Hz. But its likely that your main speakers go lower than that, so this should be fairly easy. Below 80Hz your ear cannot tell where the bass is coming from- and the harmonics of the bass instruments will make you think that the bass is coming from in front of you. Two of the subs would be placed in front of you, and the other two placed asymmetrically in the room, with one maybe on one side wall and other other in the rear on the opposite side. You might get better results by putting one of the latter two out of phase with the rest. They can all be fed a mono signal- again, if kept below 80Hz this will work fine. To get bass evenly distributed at all frequencies this is the most elegant approach. There is one subwoofer that is built specifically for this purpose, the Swarm, made by Audiokinesis in Texas. Good Luck! |
Headphones are amazing these days but do not get me to the same level of musical greatness as a great speaker. I say this as someone who sold my amps this week and have nothing to drive my speaker. Just 2 great headphone systems today. |
If you are doing this for one listener...use your headphones, you will save alot of money. |
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You may want to give your local guy mitch a call,
https://accuratesound.ca/
Are you doing mostly digital streaming with ROON or JRiver? |
Bass traps and possibly 2 subs may be necessary. Start with the traps.
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Your room dimensions are even numbers with common denominators (all divisible by 4...your room was certainly not designed by an acoustics engineer, lol). You’re going to have significant standing waves and bass issues regardless of positioning. Best thing you can do is increase the acoustic space with significant bass trapping. Contact GIK Acoustics and they can help you come up with a custom treatment plan. |
Imo, had I that room (and it were dedicated) I would not put the system on the long wall, but the short wall, and put the listening chair about 8' away to start. Like so (see my system)
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Move speakers about 12” away from wall.
Them sit and listen, move back 6”’s, sit and listen.
Move farther from wall if needed.
Mine are about 11-13” from the wall they are on, I’m 9 feet from them with speakers toed in slightly to my sitting couch position.
I have small woofers, 6-7” drivers, and I get descent bass from mine.
I also put our throw pillows behind the speaker in the corner, which corner speakers tend to sound louder and have more bass than the speaker which is on the wall To the left, it is 10” from a open hallway, staircase, bedrooms. Right speaker is in the corner and has a deeper and louder sound.
I all plays well.
Mess around and have fun!
my speakers are about 9 feet apart, and I sit 9 feet from them, for my small towers, it’s perfect for me.
Move, listen, move again, pillows, move again, repeat, pour self a dram and get some fav cds, and enjoy the fun.
Keep us posted! |
Your speakers are 4.5 foot apart and your 4.5 feet from the speakers?
That is close to you and close together. WOW!
You are in the wrong place and so are the speakers, it sound like, a bit of humor. Your in the "cancel zone", if the bass was trapped you would have bass, its the bass bouncing from everywhere to the center (where your at) that's the problem. Cheapest solution move your position.
Correct solution, treat the room as much as you can, place your speakers further from you and wider, get yourself a lot closer to the actual, bass bins, either side of you, or forward of the main speakers, it's a timing issue. Either kill the unused bass or get rid of it, (open the doors on the back wall if you have them). Then you can hear the bass in phase, (correct timing).
Regards |
I have a single 12” sub in an open ended approx 15x25 room. My first location produced bass 20’ away but very little in the listening area. Moving the sub only a foot and a half, close to a wall ( 4”) and experimenting with forward and side firing (into a corner worked best) produced smooth response in the listening area. The sub is across the room from the main speakers (Wireless helped here). Placement next to the mains seems intuitive but may be just the wrong thing for your room nodes and it’s not necessary if the crossover is set properly. Good luck! |
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Bass nodes.
All you need is 2 more subs and hours to spend setting them up. |
