S

Space2013

Audioholic
I’ve been very happy with my current setup which is 5 RBH Impression speakers and an RBH I12 subwoofer upfront. However, I think I may have some nulls from the subwoofer at the MLP, because as I walk around the room the bass seems stronger and fuller. I did the subwoofer crawl but there are only 2-3 spots I can put the I12 as it is huge and space is limited in our living room. I also can’t go dual woofer because RBH doesn’t make the I12 anymore plus I wouldn’t have any room for it.
Honestly it is ok as is, and maybe this is the best I can get in a multi-use room, but I was wondering if there were any good options for addressing the nulls with a small, high quality near field sub or something else I’m not thinking of?
 
William Lemmerhirt

William Lemmerhirt

Audioholic Overlord
It’s possible that the LP isn’t experiencing nulls as much as where you’re walking around is in peaks. That’s why we use rew. My response is flat as a board from about 14hz up to 80hz. When I walk around I definitely hear peaks, and then I sit down and I’m like, where’s all the bass? Lol. I would only worry about the LP and not the rest of the room.
A crude and dirty way to find out is an spl meter app for your phone(if you don’t have a real meter). Play individual tones from say YouTube, and look at the response. Start at 20hz and work your way up past the XO point by say 20hz.(XO is 80 measure to 100 or 120).
Use C-weighting, slow response, and make sure the microphone is where your head would normally be. Graph paper can help you plot out the FR and keep track of results. Takes a looong time, but it’s cheaper than a umik and rew(free, but learning curve is steep). Repeat in different locations to see results there too. If you get that far, then we’ll try and figure out what to do with results.
 
S

Space2013

Audioholic
It’s possible that the LP isn’t experiencing nulls as much as where you’re walking around is in peaks. That’s why we use rew. My response is flat as a board from about 14hz up to 80hz. When I walk around I definitely hear peaks, and then I sit down and I’m like, where’s all the bass? Lol. I would only worry about the LP and not the rest of the room.
A crude and dirty way to find out is an spl meter app for your phone(if you don’t have a real meter). Play individual tones from say YouTube, and look at the response. Start at 20hz and work your way up past the XO point by say 20hz.(XO is 80 measure to 100 or 120).
Use C-weighting, slow response, and make sure the microphone is where your head would normally be. Graph paper can help you plot out the FR and keep track of results. Takes a looong time, but it’s cheaper than a umik and rew(free, but learning curve is steep). Repeat in different locations to see results there too. If you get that far, then we’ll try and figure out what to do with results.
Thank you! I will give that a shot. I have not done that before and it will be a good learning experience. I do not have a real meter so I'll use my phone as a basic one and get an SPL meter app. I could just be hearing peaks, so it will be good to see what the data shows. What interval do you measure to start with? Every 5hz?
 
William Lemmerhirt

William Lemmerhirt

Audioholic Overlord
Yeah, 5hz should give good enough resolution. I used to use free printable graph paper to help. I do NOT miss those days, but it should be a good exercise for you to learn some more about your system. I would also make sure audyssey is off and then run audyssey after you find the best spot. That will help a lot as audyssey should have less corrections to make.
Have fun!
 
KEW

KEW

Audioholic Overlord
You can save a little time by running 5Hz intervals from 20-40Hz, then 10Hz intervals from 40Hz to 80Hz (or where ever you cross the subs plus 20 (100Hz if you cross at 80Hz).
This is because a 5 Hz interval at 20Hz is the same difference in pitch as a 10Hz interval at 40Hz. So, unless you see the need to increase the resolution as the frequency increases you can save some measurements!
 
William Lemmerhirt

William Lemmerhirt

Audioholic Overlord
You can save a little time by running 5Hz intervals from 20-40Hz, then 10Hz intervals from 40Hz to 80Hz (or where ever you cross the subs plus 20 (100Hz if you cross at 80Hz).
This is because a 5 Hz interval at 20Hz is the same difference in pitch as a 10Hz interval at 40Hz. So, unless you see the need to increase the resolution as the frequency increases you can save some measurements!
Good point Kurt!
 
S

Space2013

Audioholic
I know it has been a while but I finally got around to trying this. Again, this is just a very rough test using YouTube test tones and an SPL meter app on my phone (at the MLP ear level). I set the volume to a reasonable level (but no where near reference) and played the following tones. Crossover set to 80Hz.

Without Audyssey:
100Hz - 77.2 dB
90Hz - 80.5 dB
80Hz - 79.9 dB
70Hz - 71.7 dB
60Hz - 76.1 dB
50Hz - 62.6 dB
45Hz - 65.7 dB
40Hz - 79.3 dB
35Hz - 76.3 dB
30Hz - 70.5 dB
25 Hz - 68.5 dB
20 Hz - 59.2 dB

With Audyssey:
100Hz - 64.6 dB
90Hz - 71.5 dB
80Hz - 74.5 dB
70Hz - 75.3 dB
60Hz - 75.5 dB
50Hz - 68.6 dB
45Hz - 68.7 dB
40Hz - 74.2 dB
35Hz - 73.2 dB
30Hz - 69.8 dB
25Hz - 67.0 dB
20Hz - 60.8 dB
 
S

Space2013

Audioholic
Excellent. Curious about your experience.
I finally did this test (see post above), but it was very inexact using my phone. A slight movement of only an inch could easily change the level by +/- 2 dB. However, again, this is just a rough estimate to see if it is even worth investigating further and if a second near field subwoofer is worth the trouble trying to even it out. Let me know what you think.
 
ryanosaur

ryanosaur

Audioholic Overlord
You didn’t say anywhere in here if your crawl spots and your “logical” placement locations match up. This is not the most dire of details, but the room acoustics can’t be hacked without much more involvement and potential cost.
That said there are a few things you can do to investigate further if you have the patience and desire.
The main thing I see requiring attention is what is happening in the range from 40-60Hz. Can you find a way to set your phone up at you LP so that you don’t have to handle it/move it? As you noticed, a slight nudge can disrupt your readings.
Anyway, stack up books or amazon boxes; whatever it takes. Do your test sequence again, and look for the anomaly... in the case shown above, between 40-60Hz. If that repeats, you need to look at that in greater resolution. So run test tones every 5Hz without touching your phone, if you see the dip at two points, do a tone between them (i.e. 50 is low above, so I would micro test from 45 to 55 to see that with greater resolution). When you find the actual low point, look at the frequency wavelength and see if the subwoofer is that distance, or half that distance from I wall. That you may fix just by moving the sub an inch or two. That dip may also show up an octave higher, too (if the dip is centered at 52, you might see it again at 104Hz).
Slightly more challenging to deal with would be the room itself. For that I would seriously urge you to use the best location from the subwofer crawl.
Hope this helps.
 
lovinthehd

lovinthehd

Audioholic Jedi
Getting a stand/tripod for your phone a possibility for better repeatability on positioning? Are you holding it in your hand or ?
 
Pogre

Pogre

Audioholic Slumlord
I know it has been a while but I finally got around to trying this. Again, this is just a very rough test using YouTube test tones and an SPL meter app on my phone (at the MLP ear level). I set the volume to a reasonable level (but no where near reference) and played the following tones. Crossover set to 80Hz.

Without Audyssey:
100Hz - 77.2 dB
90Hz - 80.5 dB
80Hz - 79.9 dB
70Hz - 71.7 dB
60Hz - 76.1 dB
50Hz - 62.6 dB
45Hz - 65.7 dB
40Hz - 79.3 dB
35Hz - 76.3 dB
30Hz - 70.5 dB
25 Hz - 68.5 dB
20 Hz - 59.2 dB

With Audyssey:
100Hz - 64.6 dB
90Hz - 71.5 dB
80Hz - 74.5 dB
70Hz - 75.3 dB
60Hz - 75.5 dB
50Hz - 68.6 dB
45Hz - 68.7 dB
40Hz - 74.2 dB
35Hz - 73.2 dB
30Hz - 69.8 dB
25Hz - 67.0 dB
20Hz - 60.8 dB
Hey, good job taking advice and running with it. HD has a couple of questions regarding your method that are relevant, but you're doing your due diligence.
 
S

Space2013

Audioholic
You didn’t say anywhere in here if your crawl spots and your “logical” placement locations match up. This is not the most dire of details, but the room acoustics can’t be hacked without much more involvement and potential cost.
That said there are a few things you can do to investigate further if you have the patience and desire.
The main thing I see requiring attention is what is happening in the range from 40-60Hz. Can you find a way to set your phone up at you LP so that you don’t have to handle it/move it? As you noticed, a slight nudge can disrupt your readings.
Anyway, stack up books or amazon boxes; whatever it takes. Do your test sequence again, and look for the anomaly... in the case shown above, between 40-60Hz. If that repeats, you need to look at that in greater resolution. So run test tones every 5Hz without touching your phone, if you see the dip at two points, do a tone between them (i.e. 50 is low above, so I would micro test from 45 to 55 to see that with greater resolution). When you find the actual low point, look at the frequency wavelength and see if the subwoofer is that distance, or half that distance from I wall. That you may fix just by moving the sub an inch or two. That dip may also show up an octave higher, too (if the dip is centered at 52, you might see it again at 104Hz).
Slightly more challenging to deal with would be the room itself. For that I would seriously urge you to use the best location from the subwofer crawl.
Hope this helps.
Thanks! I will do that. Yes, I’m holding the phone in my hand, although I repeated each test 3 times to try and account for variability and I did some extra tests at the 40-60Hz range because I noticed the dip. I’ll do it again with the phone in a fixed position as close to ear level as I can get.

Unfortunately it is a mixed use room and the I12 has a rather large cabinet, so I have very little flexibility in subwoofer placement. But I have enough space to move it 2-3 inches in any direction.

Besides slight movements of the sub my only real option is to get a smaller near-field sub behind the couch to fill in the gaps, and thus this thread was born to see if it is even worth it. If I can get a single sub to work well enough, then I’ll be happy, as it sounds like setting up a near-field sub is kind of complicated. But if a near-field will make a big difference I’m willing to dive in. Looking for good, not perfect (that was hard for me to say).
 
S

Space2013

Audioholic
You didn’t say anywhere in here if your crawl spots and your “logical” placement locations match up. This is not the most dire of details, but the room acoustics can’t be hacked without much more involvement and potential cost.
That said there are a few things you can do to investigate further if you have the patience and desire.
The main thing I see requiring attention is what is happening in the range from 40-60Hz. Can you find a way to set your phone up at you LP so that you don’t have to handle it/move it? As you noticed, a slight nudge can disrupt your readings.
Anyway, stack up books or amazon boxes; whatever it takes. Do your test sequence again, and look for the anomaly... in the case shown above, between 40-60Hz. If that repeats, you need to look at that in greater resolution. So run test tones every 5Hz without touching your phone, if you see the dip at two points, do a tone between them (i.e. 50 is low above, so I would micro test from 45 to 55 to see that with greater resolution). When you find the actual low point, look at the frequency wavelength and see if the subwoofer is that distance, or half that distance from I wall. That you may fix just by moving the sub an inch or two. That dip may also show up an octave higher, too (if the dip is centered at 52, you might see it again at 104Hz).
Slightly more challenging to deal with would be the room itself. For that I would seriously urge you to use the best location from the subwofer crawl.
Hope this helps.
Any recommendations on test tones online? I found some on YouTube but they only go in 5Hz increments.
 
ryanosaur

ryanosaur

Audioholic Overlord
Any recommendations on test tones online? I found some on YouTube but they only go in 5Hz increments.
See if you can download Power Tools by Bass Mekanik. He’s a DJ and auto-sub competition guy. *shrugs The album is useful, though. I found it on Apple Music.
 
S

Space2013

Audioholic
I'll do some testing this weekend. Quick question: if I did eventually go down the path of getting a near-field subwoofer. Would it be better to get two smaller matching subwoofers (one in the front of the room and one behind the couch)? Or keep the I12 doing front duty and get something smaller but still powerful for behind the couch? With the room setup there is no way to get two subwoofers up front. A second one would have to go behind the couch.
 

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