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Post by superace on Feb 10, 2021 5:04:55 GMT
arqen.com/acoustics-101/speaker-placement-boundary-interference/ and I also saw Hexspa's video on the subject. I read through this article which states that speaker monitors should be placed as close to the wall as possible or less than 3.3 feet within a room to mitigate SBI. I have a pair of Yamaha HS8 which are rear ported and the manual states they should be placed at least 5 feet from the wall. What do I do? Do I ignore the manufacturer's instructions and place it close to the wall? Should I also place an acoustic panel behind my speaker if I put it that close to my wall?
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Post by Deleted on Feb 10, 2021 15:36:39 GMT
Placing them 5ft from the front wall, the front wall interefence would be around 55hz. What are your room dimensions?
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Post by superace on Feb 10, 2021 17:40:27 GMT
17 x 14 x 9
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Post by Hexspa on Feb 11, 2021 9:19:07 GMT
I think the idea is 'all the way in or all the way out'.
With the speakers close to the wall, the SBIR is high enough in frequency that a nearby absorber will handle it. With speakers further out, you can push the SBIR below the cutoff of the speaker. But SBIR isn't the whole story.
Sure, you get the flattest response in an anechoic environment but there's practicality to consider. The best place is in the wall with infinite baffle. You have to put your speakers where you can so experiment. If you can pull them out far enough so that SBIR is minimal due to the low frequency then do it. If not, try to balance your speakers so they compliment one another - peak on one side and a null on the other.
Your speakers are going to receive interference in three dimensions so you'll need absorption regardless. If you have to position your speakers in free space, more absorption will give you the most flexibility.
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Post by Deleted on Feb 11, 2021 11:33:32 GMT
Remember; how ever you position your speakers, the room wins, every time. I would put the speakers on a room that size as close to the front wall as possible.
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Post by rock on Feb 11, 2021 13:35:19 GMT
Yeah, there's more than one variable. When you move the speakers away from the wall, you force the LP out too. If you want to shoot for the 38% spot, that will limit how far you can place the speakers in the room. The HS8 rear ports are another limitation. Wide band absorbers on the front wall behind the speaker may help?
As far a Hexspa's hypothetical(?) "flush in the wall mounting", with the HS8 rear ports, you'd need to open the wall to a room or large space behind the front wall...probably not very practical.
So yeah, I'd have to go with closer to the front wall but with testing and measuring you'd zero in on the best compromise. But in any case, as always, adequate treatment is required.
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Post by Hexspa on Feb 12, 2021 5:15:53 GMT
Oh, no, I wasn't suggesting flush mounting HS8s. Sorry, sometimes I miss things. I was just referring to that being the best option in general with speakers that are designed for it. I really don't know too much about it anyway. And, yes, the listening position is critical. I didn't mention it since I took that for granted. Good eye, rock.
As far as outright 'mitigating' SBI with pure positioning, in theory, the further from the surface, the weaker the reflection by the time it returns, right? I think it's just that SBIR is distance-frequency dependent. I forgot what the EBU paper recommended and I think the Grammy paper had a recommendation too for speaker distances. Something like 5-7' - more than is usually practical for small rooms.
Find your listening position, put the speakers where you can and try a few places to see which gives you the best response. From there you can add treatment. That's how I'd do it in a normal-sized domestic space. Not sure if anyone mentioned it but, if in your quest for minimizing SBIR you put your speakers in a corner, you might end up with unwanted bass reinforcement. Measuring acoustically helps a lot.
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Post by rock on Feb 12, 2021 14:58:52 GMT
Hey Hexspa, Sorry if I mischaracterized your comment, I think I understood you were using flush mounting as an example and not an actual recommendation for this situation. Yeah, the HS8s are probably not the best speaker choice for flush mounting. No disagreement here! Good point about speaker placement with respect to bass reinforcement. Here's that article I posted before www.prosoundtraining.com/site/wp-content/uploads/2012/03/VOL36_DEC08_Boundaries-1.pdfAs we have seen, some speaker systems can be switched for the type of placement. Yeah, I'm totally on board with you about acoustic measurements, it can only help. As far as measuring is concerned, and this could be a thread on it's own but, I was thinking we should really be making near field measurements of our speaker systems first (as best we can) for a baseline for our room measurements. We'll never correctly fix a peak or dip in speaker response with acoustic treatment. |
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Post by Hexspa on Feb 14, 2021 7:35:46 GMT
I think I subconsciously visualize that link when talking about bass reinforcement, haha.
For sure, rock, I agree: placement first, then treatment.
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