Looking for some advice on how bad an idea it would be to build some JBL M2 clones. It's alot of money to me to do this, so I need someone who knows what they are doing to give their opinion.
Image 1 is my living room right now.
Proposal is in wall speaker version of a JBL M2. (Image 2- yellow wall added)
The 'false wall' would house a pair of M2 waveguides for my 4inch compression drivers (2452SL) and the M2 bass driver.
I don't have the D2430k M2 compression drivers, but am told the drivers I have work well and are if not better, at least comparable.
Why go through this vs buying/building some more regular speakers? SPL playback regularly reaches 112db+ at 1m for my living room, and big boxes get a no from the wife. I can also hide a large sub in the wall.
1) Is the response going to be completely screwed up by the side wall reflections and being in wall?
2) Erin (Erin's audio corner) notes that the M2 bass driver has some diffraction issues with the accordian surround. Is there a better 15 inch alternative? I have some AE TD10m drivers, but assume this would not match the pattern of the 15inch I would be replacing, and also assume distortion would be higher at 112db+ sub or not.
Current living room:
Proposed design:
Image 1 is my living room right now.
Proposal is in wall speaker version of a JBL M2. (Image 2- yellow wall added)
The 'false wall' would house a pair of M2 waveguides for my 4inch compression drivers (2452SL) and the M2 bass driver.
I don't have the D2430k M2 compression drivers, but am told the drivers I have work well and are if not better, at least comparable.
Why go through this vs buying/building some more regular speakers? SPL playback regularly reaches 112db+ at 1m for my living room, and big boxes get a no from the wife. I can also hide a large sub in the wall.
1) Is the response going to be completely screwed up by the side wall reflections and being in wall?
2) Erin (Erin's audio corner) notes that the M2 bass driver has some diffraction issues with the accordian surround. Is there a better 15 inch alternative? I have some AE TD10m drivers, but assume this would not match the pattern of the 15inch I would be replacing, and also assume distortion would be higher at 112db+ sub or not.
Current living room:
Proposed design:
FR (fixed with DSP) and dispersion (mechanical design) governs the suitability för corner placement. FR is no problem so we are left with dispersion.. What is the desired dispersion pattern for something placed in a corner, rayma?
Or is there yet an other characteristic that is important for corner placement?
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Or is there yet an other characteristic that is important for corner placement?
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Speakers in corner could be OK since bass' level can be managed easily with DSP (and it's free energy/bass!) but...my first concerned would be to address your lateral reflections caused by your lateral wall and glass.
I'd narrow the speakers' distance to allow a proper acoustic treatment. If you can't put any treatment here, at least chose a horn with a narrower horizontal dispersion to minimize this problem (only at higher frequencies though...).
You haven't mentioned the length of the room, make sure not to seat in the middle of the room (related to length).
I'd narrow the speakers' distance to allow a proper acoustic treatment. If you can't put any treatment here, at least chose a horn with a narrower horizontal dispersion to minimize this problem (only at higher frequencies though...).
You haven't mentioned the length of the room, make sure not to seat in the middle of the room (related to length).
I agree that the glass and wall left of the left and right of the right speaker are a real issue. I'd find a place on the longer side of the rectangle room you're in, but looking at glass and the couch, you're kind of stuck on that side of the room, right?!
Iow, you'll have to see if you can make this work with not too wide dispersion of the horns to minimize reflections of the glass left and wall right, while still maintaining a desired golden ratio. Dispersion of the 10 to 20 KHz range with the horn gives a good clue how much off angle towards the listening position you can place the speaker, you should look that up.
These rules are not set in stone, but may give you a good idea where to start. With normal speakers, you would move them around, change angle etc. The pros of having it flush mount, are nullified when you don't execute this right, from the start, so get as much info as you can and keep the discussion alive here, it might actually turn out really well tbh!
Golden ratio:
https://www.soundboxlab.com/hometheaters/speaker/understanding-speaker-placement-a-complete-guide/
Iow, you'll have to see if you can make this work with not too wide dispersion of the horns to minimize reflections of the glass left and wall right, while still maintaining a desired golden ratio. Dispersion of the 10 to 20 KHz range with the horn gives a good clue how much off angle towards the listening position you can place the speaker, you should look that up.
These rules are not set in stone, but may give you a good idea where to start. With normal speakers, you would move them around, change angle etc. The pros of having it flush mount, are nullified when you don't execute this right, from the start, so get as much info as you can and keep the discussion alive here, it might actually turn out really well tbh!
Golden ratio:
https://www.soundboxlab.com/hometheaters/speaker/understanding-speaker-placement-a-complete-guide/
I second keeping them away from corners. It will amplify room modes like crazy that will be obnoxious to listen to and difficult to EQ. If you can flip your plan 90 degrees counterclockwise you could have them on the wider wall to the left, but only if the wall behind the sofa is not a solid wall. Otherwise, house prices are going down in these turbulent times. 
With proper balloon data (individual sources and filters, as used in GLL files), frequency-dependent material absorption & scattering coefficients and a decent beam-traced model you can definitely simulate this kind of configuration.
The frequency range of validity is limited by the room dimensions dictating your mod at LF (Schroeder frequency or Fcrit) and mesh resolutions at HF, but typically 100Hz to 10kHz is possible for larger rooms in tools such as Odeon, EASE and CATT.
Those are very expensive tools, of course - EASE is the cheapest at €4000 for the more advanced AURA model - and measured anechoic balloon data is very rare for any DIY designs. It is possible to get balloon data out of tools such as AKABAK BEM though, and with some effort this could be formatted in the style that the free room acoustics software i-Simpa uses.
In the modal region, there are good online tools such as Amroc’s https://amcoustics.com/tools/amroc and of course REW’s model. The former is perhaps easier to visualise where and where not to place your speakers though.
Whether that’s worth the time & effort is of course up for debate, and a choice for the people who are interested in trying it
I’d recommend reading this:
https://www.prosoundtraining.com/2016/05/04/small-room-and-loudspeaker-interaction/
By "not as such" of course, I meant you'd really need to know what you were doing to be able to amass anything usable from simulations.
In any case considering that simulations don't tell you the whole picture, I'd rather that experience than the software if I had to choose between the two.
In any case considering that simulations don't tell you the whole picture, I'd rather that experience than the software if I had to choose between the two.
Allen, I think it was pretty clear that "not as such" translates into "very hard to do right and pretty much impossible if you're not already an expert in that field ", or something equivalent;-)
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The problems have less to do with the peaks, more to do with the valleys, apart from better not having them at all, of course.
The positives are also there because you have no problems generated between the back wall and the woofers, as is with normal speakers. Less troubles in the midbass section.
Just try the REW or the amcoustics link to get an idea of it.
Then still: flattening e.g. a 12 dB peak (not extraordinary), means you need to dial down that peak around 2 bits in digital systems, that's resolution out of the window one way or another that should ideally not be lost. Etc.
I got that, think most did;-)
While replying:
The format got destroyed when i deleted my message (backspace), went too far and cut into the quoted section. Never got it right again.
The top part is yours, the bottom my reply to it. Sorry for that.
I fixed it. I see it makes sense now
I have had the same happen with the editor.. I currently use it in the other mode.
