Expert Guide to Subwoofer Layout and Speaker Placement

[@matta9316]

Love this stuff - thanks for sharing!

[@PoesAcoustics]

Glad you enjoyed it!

[@hdmoviesource]

None of the preferred subwoofer layouts were Trinnov's layouts. So, my question is, can 4 subs placed at the front of the room sound better than 2 at the front and 2 at the back, corner loaded? When I say better, I mean, to have a more consistent bass response, seat to seat. The 4 subs up front, you could have 2 placed on the floor, and 2 in the ceiling. A side question, could a 3 sub approach work? I'm in a room where I could only get a 3rd sub, because one corner is where the door is to enter the room.

[@robertochs2283]

I 've had good luck with three subs. 2 up front. 1/4 points and third halfway up side wall. Centered on back wall didn't fix a 60 hz null. Side did. +/- 4 db from 20-100hz. Experiment...

[@PoesAcoustics]

Geddes found three to work fine. The issue with three vs four is that placement becomes trickier. Where the four sub method that Todd promoted worked well in most rooms with east sub placement recommendations, the three sub approach proved harder to get right. Waveforming wasn’t mature enough to incorporate into RP22. That is one is the things we will address in future versions.

[@hdmoviesource]

@@robertochs2283 Thank you Robert. I'm considering it.

[@hdmoviesource]

@@PoesAcoustics Thank you Mathew. My option is to have two subs upfront and one 75% of the length along the left wall.

[@jasonjones8735]

Thanks for all the videos. One question I have is: If using wave-forming does a sealed sub still benefit from room gain?

[@PoesAcoustics]

Absolutely. Nothing waveforming does would prevent the benefits of Waveforming.

[@nattydj8646]

Awesome! Thanks for sharing.

[@PoesAcoustics]

Thanks for watching!

[@simpsonbergman2185]

Very interesting. I found through experimenting that facing my subwoofer directly at the wall improved the output. (It also made the controls on the subwoofer easy to acces!) But maybe it was due to more room gain. That was a small 10 inch sealed subwoofer.

[@MyFatherLoves]

I currently use a quasi-A setup. One sub on the front wall, one on the side wall, ideally combining to one "virtual" sub at the front right 1/4 in the room with another identical pair on the front right of my room. If that makes sense.

[@ruvamsi]

This is how I have my 2 subs. Put my first sub in front right corner then found a huge null along the right side wall. Put the 2nd sub in the point of the null. The performance is much better than my original layout of subs right next to mains.

[@pauledwards8721]

Quick ques on RP22 - unless I missed it, why doesn’t it include Tactile Transducers? 🤔

[@PoesAcoustics]

Because no experts like them. None of us feel they add positively to the experience over other methods. They aren’t used in dubbing stages. Meaning their effect isn’t part of the monitoring of the original content by creatives. Our goal was to develop best practices to recreate the artistic or creative intent.

[@MyFatherLoves]

I've been trying to find exact guidelines from Dirac for ART. Do you have this information or can you point us to this information?

[@commanderrussels2612]

Great video! I wish more subwoobers were only 12" deep or so. I think my nexy system I'd highly prioritize this. 18"-24" deep subs is a disadvantage for a lot of applications.

[@PoesAcoustics]

I’ve been pushing this with manufacturers. I think you underestimate how deep some get. I am ok with 18”. 24” is pushing it. But some are even longer than that. The problem you run into with shallow sub enclosures is that it necessarily limits the ability to have long coils and high excursion. So you can end up compromising the performance a bit. RTJ has managed to fit an 18” driver into a 15.5” deep enclosure that has over 30mm of xmax. But to scale it to 12” he has to move to a 12” driver. It’s a common issue.

[@Palindromeguy1]

So with waveforming and Dirac ART, does this mean we should be buying eight or more subs or buying surround speakers that can handle below 40hz or both. How are these technologies changing the future of home cinema???

[@PoesAcoustics]

It’s a good question. It changes things quite a bit. With ART, surround speakers that have wider bandwidth and higher output or wall mounted subwoofers are of value. However I fear that some may misinterpret this. Many bookshelf speakers may claim bass down to 35hz. They may even have bass that low. Not with any real output though. ART could end up destroying that speaker if you misapplied things. An actual on wall subwoofer or specially designed speaker makes more sense. As for Waveforming. 8 subs isn’t a requirement. Not that it’s a problem. But 4 is the minimum and for many could be enough. I think the sweet spot will be 5. Three in the front and two in the back. I suspect the performance will be excellent in a lot of rooms.

[@TheoM-bx3lx]

Audio echoes

[@Hamza-yu1ur]

What about nearfield subs?

[@commanderrussels2612]

i think the industry term for those is mitwit subs

[@PoesAcoustics]

More gimmick than tactic. It doesn’t smooth out the bass beyond the general benefit of more LF sources. Some people think that by being so close you sit in the near field and don’t have room modes. That isn’t true, room modes are as present as ever. Waveforming and art are a more sophisticated solution that can actually create a large area with identical bass. But having played with those and other solutions. I’ve found other solutions to be more effective in this regard. Ultimately I don’t use them in my work. What near field subs do is provide more tactile bass.

[@genkifd]

active sound treatment sounds very expensive

[@PoesAcoustics]

In theory it’s much cheaper than passive. It’s just code.

[@genkifd]

@@PoesAcoustics but dont you need some sort of a active device to cancel out certain unwanted frequences / reverb. which means to me an active wall(s) of some sort would be required.

[@CarlVanDoren61]

Stadium's use line array pa 🔊 Home audio is much simpler

[@pulDag]

Different applications different issues.

[@alwayspushing2031]

I am no engineer so I ask coming from just a guy that likes bass. I rarely hear anything about mixing of subs, not sealed vs ported but like what I am getting ready to do. Dual SVS SB3000's up from and dual Starke SW15's in the rear, all sealed.

[@pulDag]

And what is the goal? With sealed subs you have better chance to do that for sure and if those subs have similar decay (group delay)..

[@pauldavidthomasfrodo]

I'm normally awfully positive... And, if you can't say anything nice and all. But, as you probably know the acoustics on the recording were not great to the point of being really hard to understand - and the irony of this being a presentation about acoustics :-) We all know it was the room, but I am not sure if you could get either a better mic, or wear a mic to assist. Actually, engaging brain that's not going to work as you have multiple speakers - at it were !!! I found the area of nodes / modes quite confusing, and this could be because we got a snippet of a longer presentation and if I were being 'taught' I would have found the explanation, not as much confusing, but not very well explained. That sort of manifests itself in a lack of audience response. I think a lot of these subjects, whilst complicated could be explained a little better. Sometimes getting someone that does NOT have an acoustic background to assist in designing a presentation. In the same way as ( back in the day ) developers would employ technical authors to document what they were doing as the developer was so coupled to the subject it was hard for them to explain to less well educated people. So, this is not a personal thing, it is in fact a general education issue and you were also in the presence of peers who add that little extra stress which always effects us. You kinda had three or four presenters, but as it was prob. an open-forum kinda education session then it's ok. I hope the people in the room appreciated the time served teachers they had in the room. I think recording more of these sessions does not diminish your ability to remunerated yourself ( as you should ) but increases it and it has been seen by many youtubers you give out free info / education and get a return on private consultations. I'd like to know if there was a way to remove / reduce the poor audio for future presentations. Or was the room really that bad as I'm sure you have no control over a venue. Oddly enough I take my 3 year old to a nursery session in one hall. The acoustics are so bad I just cannot go there anymore. It really is awful. Right, if I'm off to work now, I will be on a roof. I'd rather be else where. And, once again. Thank you for your video's. $THANKS

[@PoesAcoustics]

The original intent wasn’t to post this. It was meant as BROLL. But once we got into what I shot, we didn’t have a use for it. So my wife felt it would be nice to at least post it. You are getting a snippet of a larger activity and audience participation would have been mostly in appropriate outside of some questions. While Peter has taught this many times now, it was my first time using his material. I think my own presentation skills were not great but I also know I can be a good presenter and educator. I am racking it up to the difficulty in using someone else’s training material for the first time.

[@northeastcorals]

@@PoesAcoustics Obviously you haven't got the time to properly record every single thing you participate is so I definately appreciate you posting this kind of content for us as I'd prefer to see something rough & ready than not see it at all 👍

[@pauldavidthomasfrodo]

@@PoesAcoustics The more you do it, the better you get. I used to present IT 'stuff' with IBM and I always found physical things helped. Letting the audience get involved with 'things' assisted a lot. Equally a bit of hands on, passing around some physical object you are discussing works well. Do I think putting this out is good ? Hell yes. Does it matter that is was not ' polished', not at all. Anyone who is interested in this will have empathised with your situation. You wife's judgement was correct ( they usually are ) about putting it out. From your videos it is easy to see you care about what you do. So, I would not worry too much about stuff .... even though I know you will. Oddly enough a podcast I listen too 'Hidden Brain' talked about the issues of trying too hard. Your doing great stuff, so keep on doing it.

[@PoesAcoustics]

@@pauldavidthomasfrodo this was a very hands on course. We just didn’t show that in the video. So you get like 20 minutes of lecture. Then 20-30 minutes of hands on application. Everyone had a room with furniture, speakers, etc. they then had to draw a screen in. Place the furniture where it goes. Place the speakers. And calculate all the angles in accordance with RP22. The goal was to design the best room possible balancing all the challenges.

[@jordanhermant659]

I can see my leg...