Recommendations on corner traps

[pask74Participant]

Hi John,

What type of corner traps are the most effective?
- Fully filled with compressed mineral wool
- Fully filled with normal mineral wool
- Just a mineral wool panel
- Any other design

Thanks!

[John BrandtParticipant]

Most effective.. Hmmmm. That's a trick question!

It depends on the frequency range of interest... let's talk about under 100 Hz:

I normally trap corners as deeply as possible, but after about 16" deep, the lightweight, fluffy stuff (not compressed!) becomes reflective. Therefore, I will integrate wave guides wrapped in 2" of fiber. There should be space between them so that air flow (sound flow) past them is uninhibited. The wave guides should be massive. I use 3/4" MDF.

THAT is the most effective corner trap. Next step up would be similar with a membrane next to the corner boundaries.

Cheers,
John

[timmymacParticipant]

My room was designed by John. The wave guides blew me away once I installed them.

[Jeff MacdonaldModerator]

@timmymac How was the experience working with John? I am looking for a designer at the moment and would love to hear from you how things went with your design if you are willing to/able to share.

Thanks,

Jeff

[timmymacParticipant]

John was great! I had initially built a few 6" panels for an RFZ type setup, but wasn't really happy with it. Once I got John involved he repurposed my panels for the ceiling cloud and spec'd out everything I needed to do for the walls. It was super helpful to have someone who knows what they are doing to help with the design. I read a lot of acoustics books and forum posts with the intention to just DIY the whole design, but there's a lot of misinformation and outdated material out there that makes it difficult to determine what's good and what's not so great (unless you have infinite time and money to try out a lot of different things..I didn't). Hiring John helped me cut through all that noise. My room is small, roughly 11.5ft x 16ft. So John was able to layout the panels to best work within my room. Different size rooms will require different treatment. Also my room isn't perfectly symmetrical so there are some compromises. But it's a bedroom, heh! Since it's a small room there's a lot of absorption and bass trapping, but it's not entirely dead. There's a certain percentage of reflective surfaces integrated into the design. It's very comfortable to hang out and work in.

I built all of the panels myself with plans from John. Basically the panels are stick frame with different combinations of OC703, pink stuff and with/without wood slats on the faces. I had a local lumber shop cut 8' by 1-1/2" sticks from plywood for me and then I cut them to length for making each floor to ceiling panel. If I had a table saw I would have done it myself, but well worth the extra cash to have them do it on a nice professional saw. I considered using 1"x2" pine but they tend to not be straight. I used pocket screws to join everything together which made things go quick. No glue was used since everything was wrapped in muslin and burlap which really held everything together nicely. I purchased the burlap from ATS which was very reasonably priced. Screw the Gilford of Maine stuff, it's nice by way expensive.

It took me about 6 months to complete, working on and off just on the weekends. I took my time and did it all by myself. If I hustled and had a helper, I could have probably done it in 2 weeks straight. I'm also a perfectionist so that doesn't help. 🙂 I also had to work under one constraint enforced by my wife which was that all the panels must be removable. If I ever do it again I think a permanent installation would go up quicker since I'd only have to upholster the front. Upholstering is the hardest part in my opinion. But trust me, you'll be a pro by the time you're done. And it's not so hard once you figure out not to stretch it too tight.

Also, John has been super responsive and helpful with answering all my questions, even a year later. He's a great resource and definitely worth considering.

Hope this helps and I'm more than happy to answer more questions on here or offline.

[Jeff MacdonaldModerator]

Wow thanks for all the info. I am in the process of trying to get him to do my design as well. It sounds like his plans are extremely thorough. Do you have any pictures of the final build by chance? I would love to see what you built.

Also, I still owe you some CAPI 312/26 drum recordings - I haven't forgotten about ot, I've just been completely overwhelmed trying to sell our home and get another that is more 'studio friendly' - hence asking you about John's services. I ended up with a 34x28 garage with 14' ceilings so hopefully I can get a decent space in there. I will get some recordings soon though and get them posted - I also just picked up a pair of the colour CP-5 pre (they are 20% off this weekend, so I'm looking forward to building and trying those as well.

Cheers,

[timmymacParticipant]

whoa! that sounds like a great size for a home studio!! I have dreams of moving to a new place and building a big studio in a barn. Maybe someday ?.
Attached one photo. I'll get some better ones posted.
I have 4 capi vp26 pres now. Been using them mostly on guitar. Still need to try them on drums.

[Jeff MacdonaldModerator]

I am quite excited about finally having the space, it took a bit of sacrifice moving quite a bit further out of the city, but I think it will be a nice trade-off. I suppose this was my 'someday' - I had been planning this for about 8 years and it still doesn't quite feel real, and it likely won't until the empty space is completed. It's probably time to start calling in favours from friends to help with the labour, lol.

That room looks amazing! How long did the design process take with John once initial contact was made?

[timmymacParticipant]

That's great! For me, having a small single room, the design process was very fast. I sent John a detailed drawing of my room and then we did a Skype session where he designed it in autocad while I watched. Then he sent over very detailed drawings and a lot of docs on building all the treatment. Definitely get some help with the build if you can. Will go faster and more fun.
Side note: Attached pic of new desk I recently built.

[Jeff MacdonaldModerator]

That desk is absolutely stunning! Is the top a solid hardwood? I suppose I should start trying to factor in furniture as well, oh the million things that come with changes haha.

Thanks again for all the insight on this process - I spoke to John briefly over email yesterday so I am going to set up an initial consultation for this week.

[timmymacParticipant]

Thanks! Yes the top is solid black walnut. It's basically my take on a sterling desk but not as deep and no covers, which I really like. And also not over 4000 dollars. It cost around $500 in materials. I'll post more on a different thread. Sorry for hijacking.
Yes, so many decisions to make which is why I hired John. Good luck with the build! Exciting!
Oh and I'll post more detailed pics of how I built the panels using pocket screws. Made it really easy!

[Jeff MacdonaldModerator]

I'd love to see more on the desk in thread or else where - I suppose I did take pask's thread and run it slightly off topic. Did you document the desk build at all? Maybe the DIY section would be good for that thread.

I am really enjoying pocket screws lately as well. I wasn't sure at first but they certainly speed up joinery and are a lot neater than face nailing things. I'd be very interested in that.

Cheers

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