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Post by Boomzilla on Nov 20, 2019 6:58:25 GMT -5
There is significantly conflicting advice available on the internet concerning this question. Some of the contradictory instruction I've found says:
Place two subs along the speaker wall at ¼ and ¾ distances of the total room width
Place two subs in opposing corners
Place two subs on opposite walls away from the corners
Crawl around the room periphery with the sub in the listening position (a silly and impractical suggestion)
Leave the subs on the floor
Lift the subs above the plane of the floor
Place subs at positions from each room surface such that no distance is an exact multiple of another
The last seems to make sense from a resonance standpoint - the fewer frequencies that can reinforce via room echo, the smoother the frequency response should be.
Assuming that to be the case, what stands are commonly used for subs? And should a pair of subs be equidistant from the floor, or different heights? It would seem that the latter would be more effective, despite being less aesthetic.
Now this isn't anything worth obsessing over, but at the same time, I want the best performance possible for the money I've invested. And placement costs nothing but time and effort.
And finally, when considering the "size" of a room, how should one include open adjacent areas such as foyers, hallways, stair openings, and openings into other rooms?
Thanks - Boom
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Post by 405x5 on Nov 20, 2019 7:24:53 GMT -5
There is significantly conflicting advice available on the internet concerning this question. Some of the contradictory instruction I've found says: Place two subs along the speaker wall at ¼ and ¾ distances of the total room width Place two subs in opposing corners Place two subs on opposite walls away from the corners Crawl around the room periphery with the sub in the listening position (a silly and impractical suggestion) Leave the subs on the floor Lift the subs above the plane of the floor Place subs at positions from each room surface such that no distance is an exact multiple of another The last seems to make sense from a resonance standpoint - the fewer frequencies that can reinforce via room echo, the smoother the frequency response should be. Assuming that to be the case, what stands are commonly used for subs? And should a pair of subs be equidistant from the floor, or different heights? It would seem that the latter would be more effective, despite being less aesthetic. Now this isn't anything worth obsessing over, but at the same time, I want the best performance possible for the money I've invested. And placement costs nothing but time and effort. And finally, when considering the "size" of a room, how should one include open adjacent areas such as foyers, hallways, stair openings, and openings into other rooms? Thanks - Boom It depends |
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Post by doc1963 on Nov 20, 2019 7:40:18 GMT -5
The only way to know for sure is to try multiple "acceptable" placements within the room and run FR sweeps using REW to guide you. Save all of the graphs (with notes as to the placement the subs within the room) and pick the best one. Odds are, none of them will be "perfect". Often you’ll find that the last option in your list of scenarios (above) provides the best results. In my room, 1/3rd wall front placement (between the center and mains) of my two subs provides the best results, but I feel that it worked out that way only because the “long wall” on one side of the room is longer than the other. Maybe also just coincidence, but it measures the best, so I’ve stuck with it...  EDITED: to add the word "acceptable" (because no one likes to use their subwoofer as an ottoman)...  |
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Post by garbulky on Nov 20, 2019 12:13:21 GMT -5
For subwoofer placement for smoothest response - can you guess what I recommend?  |
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Post by garbulky on Nov 20, 2019 12:16:11 GMT -5
Crawl around the room periphery with the sub in the listening position (a silly and impractical suggestion) Let me put it another way, how much time and money have you spent getting the bass right? If you don't want to crawl or bend over, don't. You can do it standing up straight and walking around the room. The work it takes to move that subwoofer to a different listening position and trying? Just do that but over to the couch. If you don't want to put it on the couch put it by the couch. Any measurements from that subwoofer crawl (or walk) are going to be better than nothing. |
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Post by Boomzilla on Nov 20, 2019 21:28:30 GMT -5
...Any measurements from that subwoofer crawl (or walk) are going to be better than nothing. And therein lies the problem - There ARE no measurements. The only thing it would yield is "yeah, I think it sounds better about here, but I can't say whether or not it was better over there. |
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Post by monkumonku on Nov 20, 2019 21:32:22 GMT -5
...Any measurements from that subwoofer crawl (or walk) are going to be better than nothing. And therein lies the problem - There ARE no measurements. The only thing it would yield is "yeah, I think it sounds better about here, but I can't say whether or not it was better over there. But then the question one might ask is, if one thinks it sounds better in location A but the measurements say location B, which one should you choose? |
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Post by Boomzilla on Nov 20, 2019 22:04:47 GMT -5
It's a matter of magnitude. If I really like the sound at location A, then that's where the sub will go, regardless of measurements. OTOH, if the two are close, then I'll pick location B in the expectation that when the second sub is measured, it will compensate for any imperfections in A's placement.
Measurements are not perfect - otherwise room correction would transport you to the original recording venue every single time. But are measurements more accurate than subjective listening? A majority of the time, yes. But once correction has been applied, in response to the measurements, a simple with/without correction test should show what sounds best. In most friends' rooms that I've heard, they get better results WITH room correction. But in my room, for some reason, I usually (not always, but by a slight majority of the time) prefer the sound without.
My room IS "different."
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Post by Ex_Vintage on Nov 20, 2019 22:34:52 GMT -5
As has been said many times. the whole thing IS subjective. Subjective listening IS more accurate to YOU as long as you like it. If it measures perfect and you don't like it, you wold "tweak" it anyway.
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Post by Gary Cook on Nov 20, 2019 23:42:02 GMT -5
Crawl around the room periphery with the sub in the listening position (a silly and impractical suggestion) The only way to do it, I grab the crawler from the garage and glide around, quite fun actually  Cheers Gary |
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Post by Boomzilla on Nov 21, 2019 0:24:49 GMT -5
The only way to do it, I grab the crawler from the garage and glide around, quite fun actually Cheers Gary Wow - never thought of that - Thanks! |
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Post by garbulky on Nov 21, 2019 0:28:09 GMT -5
...Any measurements from that subwoofer crawl (or walk) are going to be better than nothing. And therein lies the problem - There ARE no measurements. I don't understand what do you mean that there are no measurements? I suggest reading this post in its entirety as it I think you may have misunderstood the idea of a subwoofer crawl (remember you don't have to crawl). There's two ways to do this. Both are valid. One is more accurate. 1. The "by ear" way - no measurements.
You play a bass frequency sweep - found on youtube. And you listen to it in its entirety at a spot in the room and move to another spot and repeat. You figure out which spot sounded the "smoothest". The bass sweeps on youtube also have the frequency listed. So if you notice a sudden dip or peak at a certain point you can note that on a piece of paper like (Position A "large null 70 hz, minor peak 50hz, flat throughout 90-200hz"). Etc. Then move to next spot oand repeat. You compare notes and figure out which positions had the largest dips and peaks and where. 2. The more accurate way - add measurements. Here you will play a bass sweep (found on youtube) and with your phone or SPL meter record the SPL at major intervals on a piece of paper (Position A "50hz 75db, 70 hz 45 db"). Once finished move to another spot and repeat. This is a lot more useful because you can then graph it. This will provide you a comparison chart of where the biggest nulls and dips are in the room. You can then decide which is the best compromise for you. So what's the useIn both ways you can find out two things. 1. That there are certain peaks and nulls that are present no matter where you are. It is room dependent and not placement dependent. Here an equalizer would help. 2. You may have two very smooth areas. This is where you want the subs. 3. Likely you'll have several smooth areas but some of those areas will have different peaks and nulls. This is useful. Placing the subs in these areas with differing peaks and nulls over areas that have the same peaks and nulls should provide you better smoother performance. |
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Post by Boomzilla on Nov 21, 2019 12:04:14 GMT -5
I'll also try out RAIS again (redundant array of inexpensive subs)  |
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Post by Boomzilla on Nov 22, 2019 11:43:38 GMT -5
Current plan to balance four subs:
1. Play a 100 Hz. tone with the crossover inactive (subs receive full-range signal) and make sure all 4 subs have same output volume - adjust via gain knobs on plate amps.
2. Play a 100 Hz. tone (Crossover point) on the main speakers with crossover active & record SPL. If each speaker measures 80dB, the combined SPL of both speakers will be 86dB.
3. Adjust master sub volume pot with crossover active to the same 100 Hz. tone to make all subs = -6dB from 80 (74 dB). If each sub measures 74dB, the combined SPL of 4 subs will be 86dB also.
4. Adjust main/sub ratio by ear until it sounds right.
Comments or corrections?
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Post by 405x5 on Nov 22, 2019 11:52:46 GMT -5
My listening room had but ONE place for me to stick my HGS 18 with any sense of practicality.
So, there it is...end of story.
If it COULD sound any better than it does now, I will never know.
Bill
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DYohn
Emo VIPs 
Posts: 18,491
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Post by DYohn on Nov 22, 2019 12:08:39 GMT -5
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Post by 405x5 on Nov 22, 2019 12:40:47 GMT -5
Crawl around the room periphery with the sub in the listening position (a silly and impractical suggestion) "The only way to do it, I grab the crawler from the garage and glide around, quite fun actually" Those men, with the white coats come to your house with something similar when this stuff goes beyond the pale..... |
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