Two subs or To trap

The XYZ system will give you the data you need. There are some things about it I don't like as a power user, but for the job of improving the speaker/room interface, it'll do what you want. Having data is one thing however, interpreting it is another. Once you start collecting data, post screen shots and we'll help you figure out what to make of it.

If I remember the picture of your room, you had a lot of left/right asymmetry where the right side was close to 2 wall boundaries. My guess would be the majority of your problems are coming from that side, bass boost from boundary gain, and short window reflections that hurt imaging cues. My suggestion is to collect some baseline data first for both left and right side individually, and both speakers together, gated and ungated FR (taken both at 1m and your listening position), and various forms of decay times. Then apply some treatments to the right side problem area, bass trapping in the corner and first reflection point absorption, then take the same measurements again and compare.
 
Vapor1 said:
The XYZ system will give you the data you need. There are some things about it I don't like as a power user, but for the job of improving the speaker/room interface, it'll do what you want. Having data is one thing however, interpreting it is another. Once you start collecting data, post screen shots and we'll help you figure out what to make of it.

If I remember the picture of your room, you had a lot of left/right asymmetry where the right side was close to 2 wall boundaries. My guess would be the majority of your problems are coming from that side, bass boost from boundary gain, and short window reflections that hurt imaging cues. My suggestion is to collect some baseline data first for both left and right side individually, and both speakers together, gated and ungated FR (taken both at 1m and your listening position), and various forms of decay times. Then apply some treatments to the right side problem area, bass trapping in the corner and first reflection point absorption, then take the same measurements again and compare.
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Good advice, that!:congrats:
 
Vapor1 said:
The XYZ system will give you the data you need. There are some things about it I don't like as a power user, but for the job of improving the speaker/room interface, it'll do what you want. Having data is one thing however, interpreting it is another. Once you start collecting data, post screen shots and we'll help you figure out what to make of it.

If I remember the picture of your room, you had a lot of left/right asymmetry where the right side was close to 2 wall boundaries. My guess would be the majority of your problems are coming from that side, bass boost from boundary gain, and short window reflections that hurt imaging cues. My suggestion is to collect some baseline data first for both left and right side individually, and both speakers together, gated and ungated FR (taken both at 1m and your listening position), and various forms of decay times. Then apply some treatments to the right side problem area, bass trapping in the corner and first reflection point absorption, then take the same measurements again and compare.
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I will post screen shots as soon as I'm done with the testing [emoji3]
Still waiting for the unit to arrive. Can't wait!!

Thanks.
 
This is how I explain it to clients:

- the sub 100Hz range is very hard to fix, due to the fact that the room modes are spaced far apart, leading to big peaks and dips in the response
- multi-subs only provide benefits in the frequency range where they are working, which is typically below 80Hz
- benefits from multi-subs include flatter frequency response and reduced ringing, since room modes are driven destructively and speaker boundary interference dips filled
- the LR will contribute to response to about 60Hz with an 80Hz crossover
- yes, you need to crossover your LR to your subs, and not run them "full range" to get the benefits of multi-subbing
- so with multi-subs you still have the range from 60-300Hz where room modes are in "full effect", therefore you need bass trapping
- commercial off the shelf bass traps are seldom very effective below 80Hz, so it's hard to passively control room modes down to 20Hz, even with a lot of real estate...although if you build the room from scratch you can use the structure (walls, ceiling) as a bass trap. That's what we did in Len's room.
- with multi-subs I strongly advise having EQ capability on the sub feed. It's hard to control the response without it.

With multi-subs, EQ, an active crossover and bass traps you can achieve exceptional bass. Most people have bass that is pretty poor. Obviously I get to work with those whose bass is so bad they need me to help fix it, but I've been to very, very, very few rooms where the bass is what I would describe as good. Most people seem to just live with and accept crappy bass, or have not tuned their ears to it.

Ideally you'd want to get within a 5dB window at 1/3rd octave smoothing. That's quite challenging to achieve, especially in small rooms. But the most likely path to success is to use all the tools at your disposal, and to use them in the places they are most effective...ergo that means using multi-subs, EQ, an active crossover and bass traps, not just one of them.
 
Single point measurement from main listening position
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With the caveat that I'm not familiar with the application, your bass response looks pretty darned good to me for just starting the process. You have a lot of bass energy, but that could just be the mic calibration? It looks like you have constructive interference (mode) at ~28 Hz and some suck out (destructive interference) at ~45 Hz. It also looks like you have a little ringing at 30 and 60 Hz.

What are your thoughts?
 
ACHiPo said:
With the caveat that I'm not familiar with the application, your bass response looks pretty darned good to me for just starting the process. You have a lot of bass energy, but that could just be the mic calibration? It looks like you have constructive interference (mode) at ~28 Hz and some suck out (destructive interference) at ~45 Hz. It also looks like you have a little ringing at 30 and 60 Hz.

What are your thoughts?
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LOL I have no idea! Used the XTZ hard/software to analyze my room and those were the results. I just know there's a dip and it would be preferable to have a flatter more even curve. I wonder if bass traps would help and if do they ones that will blend in nicely with my living room environment...
 
kiwi_1282001 said:
That is a very good result as a starting point. If you want to know what a bad result looks like check out my system thread (link below).

The XTZ software is not identifying any room modes in the first image.

What you want to see in the first image is more dark blue colour. To get that you need to reduce decay times. To achieve that a combination of moving your listening chair position, your loudspeaker positions and introducing acoustic panels is needed.

Similar challenges at 30, 60 and 120Hz in my room were much improved with the use of GIK scopus tuned trap and Real Trap corners.
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You're Right!!! Soon after XTZ was done with analyzing, a box popped up on the screen saying "no room nodes found", what does that exactly mean?

So in your opinion, is there anything I can do to improve or should I just leave things alone? I was wondering about adding bass traps and some panels behind the speakers.
 
stanly.joseph said:
You're Right!!! Soon after XTZ was done with analyzing, a box popped up on the screen saying "no room nodes found", what does that exactly mean?

So in your opinion, is there anything I can do to improve or should I just leave things alone? I was wondering about adding bass traps and some panels behind the speakers.
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Call Nyal. He is the highest return investment you can make in your system. He will tell you what, where, and how. His prices are fair.
 
Maybe the sub has a tendency to double at low frequencies. Just raise the low level cut off a little higher. You are not going to get clean musical bass at 30kHz are you?
 
soundsrealaudio said:
What kind of acoustic problems are you having?
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I was having issues with boominess/flat bass when the sub was located in a 90 degree right angle corner. All I did was relocate it to the side that's open to a hallway and BAAMMMMM it's much much tighter and musical now....At this point I don't think adding another sub is necessary unless I want to blow the roof top.

Though I might upgrade my current SW to one that has both balanced and unbalanced inputs somewhere down the road.
 
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