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Preparing for an acousticial evaluation on Friday
Old 3rd March 2009
  #1
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BradM's Avatar
Preparing for an acousticial evaluation on Friday

Hi folks,

I'm having Bob Hodas visit my humble studio on Friday to do room analysis, evaluation, and tuning. He'll be looking at both my live room and control room. I realized last year that the weakest link in my recording chain is really the acoustic space. Both the listening environment and the performance environment can be improved. So instead of messing around I decided to hire the best. Plus he's local so it worked out nicely. heh

Does anyone have any words of wisdom regarding this type of experience? Is there anything I should do to prepare for the evaluation. What should I expect?

I have a feeling this will be one of the best investments I will ever make in my studio.

thanks,
Brad
Old 3rd March 2009
  #2
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Weasel9992's Avatar
 

Be open minded and prepared to make some changes. In the end whatever pain you might have to endure will be worth it. Have fun!

Frank
Old 3rd March 2009
  #3
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BradM's Avatar
My mind will likely be more open than my wallet. I suspect I'll be ordering more GIK panels...

brad
Old 3rd March 2009
  #4
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Glenn Kuras's Avatar
Quote:
Originally Posted by Brad McGowan View Post
My mind will likely be more open than my wallet. I suspect I'll be ordering more GIK panels...

brad
Brad,
If he has any questions we are here to help.
Old 3rd March 2009
  #5
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BradM's Avatar
I'll definitely be posting the full prognosis on the weekend. A subwoofer or equalizer might be in my future too... We'll see.

Brad
Old 3rd March 2009
  #6
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andrebrito's Avatar
Be prepared to spend money lol !

I think it is the best investment you I have done to be honest.
Old 3rd March 2009
  #7
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BradM's Avatar
I agree. It's probably going to be financially painful at first, but the results should be worth it. What's the point of buying a bunch of outboard or fancy mics if your room sucks, right? I have some good tools at this point, but my room is seriously holding me back.

Brad
Old 4th March 2009
  #8
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Weasel9992's Avatar
 

Quote:
Originally Posted by Brad McGowan View Post
I agree. It's probably going to be financially painful at first, but the results should be worth it. What's the point of buying a bunch of outboard or fancy mics if your room sucks, right? I have some good tools at this point, but my room is seriously holding me back.

Brad
Tons of wisdom in that. Let us all know how it goes.

Frank
Old 4th March 2009
  #9
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BradM's Avatar
Will do.

I'm trying to figure out what to sell to pay for this endeavor.

Brad
Old 5th March 2009
  #10
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Glenn Kuras's Avatar
Quote:
Originally Posted by Brad McGowan View Post
Will do.

I'm trying to figure out what to sell to pay for this endeavor.

Brad
your sole!!!!!!!!
Old 5th March 2009
  #11
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BradM's Avatar
I have a couple pairs of old shoes I could probably sell.

Here's a really informative webinar I found with Bob Hodas, who will be visiting me tomorrow:

There seems to be some ideas presented that are at odds with the current trend of using lots of broadband traps to help tame a room. I'd be curious to get people's thoughts after watching this:

Event Lobby (EVENT: 107574)

Brad
Old 5th March 2009
  #12
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Ethan Winer's Avatar
 

Lightbulb

That show is an hour and a half long! Can you post the high points for comment?

--Ethan
Old 5th March 2009
  #13
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Glenn Kuras's Avatar
Quote:
There seems to be some ideas presented that are at odds with the current trend of using lots of broadband traps to help tame a room. I'd be curious to get people's thoughts after watching this:
I don't have time to watch it right now, BUT part of the reason products like our 244, Monster, some of Ethans products and using FRK (DYI) are used, is it will absorb more lows then highs. If that is what the video is getting at.
Old 9th March 2009
  #14
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BradM's Avatar
Instead of summing up the video I'll just report on my experience having my room tuned by Bob Hodas on Friday afternoon. In the webinar he basically discusses the same approach that I experienced first hand.

Bob arrived about noon and unload a couple road cases of gear which contained the Meyer SIM System acoustics analysis hardware he uses to evaluate the response of the listening room. I had hired Bob to not only tune my control room, but also to give me some direction making my live room and iso room better acoustic environments.

Before we jumped into taking measurements of the control room we walked around the live room and talked about some strategies for addressing its sound. I've always felt like drums never sounded balanced in that room. There has always been a disproportionate amount of cymbal sound to drum sound. In addition, the drums never seem to have the impact I want them to in the room mics. I banged on a drum kit while Bob listened, and he basically echoed my sentiments: no resonance or bottom end to the kit when standing in front of it. There's plenty when sitting behind it, just none in front of it. He recommended that I add absorbers throughout the room to shift the balance of high frequency energy in the room and remove the diffusor cloud I had above the drum kit and replace it with some absorbers. One of the walls in the room has two glass windows and a large area covered with randomly angled plywood panels. He suggested putting up a curtain that can be drawn in front of those reflective surfaces to adjust the HF character of the room.

For my small 9x11 foot iso room he suggested what he said he generally recommends for any very small room: covering the entire ceiling with diffusion, removing the carpet from the floor, and then adding absorbers to the wall as needed to achieve the desired amount of ambience. I already had a number of GIK 244 panels in the wall and ceiling corners so I'm going to leave those in place, but just pull off some of the other DIY absorbers on the wall.

When Bob arrived the control room had two GIK Monster traps, two Real Traps Mondo Traps, three GIK 244's, six 2x4x4" DIY panels (703 or mineral wool, and two Auralex LENRDS. Some of those traps were in the corners and some were in first reflection points on the side walls and ceiling. The room is about 12x15 and has an 11 foot sloped ceiling. There are multiple doors, a window, and a storage loft above the adjacent room. So it's kind of a funky shape. To top it off I have a slightly asymetric setup to allow a pathway into the live room. We started with a measurement of my existing setup. What I saw on Bob's screen was very similar to the last measurement I had made with Room EQ Wizard. The mid bass was reasonably flat but the low end was non-existent. We're talking a severe lack of bass below 60 Hz. We focused on trying to restore the low end in the room by finding a position in the room where the left speaker gave a reasonable response. There was also some movement of the desk and measurement mic itself to optimize the console reflection and listening position. After a lot of back and forth, and left to right tweaking, we were able to find a spot where I had low end down to about 35-40Hz (I have Event ASP8's by the way) and no console reflections. I should mention that I had no idea at that point how much physical exercise I was going to be getting throughout the afternoon.

We moved the right speaker to form an equilateral trial based on the position of the mic and left speaker. We used a laser pointer to tweak the toe-in of the monitors to align the triangle. We took another measurement and found the low end of the right speaker had also been restored. However, both speakers now had some peaks and dips in the 70-150Hz region. With the speakers in place we turned our attention to the acoustic treatments in the room. This is where all the heavy lifting came in on my part. Bob had me remove various traps from the room or swap positions of various traps. Each time we made a change we would take a measurement and he would evaluate the results and have me move or swap something else. We pretty much did this for hours on end. At one point we even moved my equipment racks to see if that would clear up some problems. At various stages of the process, Bob would have me listen to some music to verify that the response at the listening position was indeed improving. Hearing deep full, full bass in the room was a very good thing.

We eventually got to a point where Bob was happy with both the speaker position and the acoustic treatments. At that point we had removed both Real Traps Mondo Traps and one GIK Monster trap from the room. After listening to some music I told him that the room seemed a little too live sounding for my tastes so we added back in some absorption, but were careful to not absorb any additional bass so that low end didn't get screwed up again. We ended up with two additional 2" absorbers on the side walls and two Auralex 2" wedge foam panels on the outer edges of the rear wall.

In phase 2 of the process Bob will fine tune the low end response using a Meyer CP-10 equalizer on my monitors, which I'm now in the process of locating and purchasing. I was given two options for equalizers: Klark Teknik DN410 and the Meyer CP-10. I'm opting to go for the better unit even though it's going to be a little more expensive. I think I'll be happier in the long run.

The whole process took about 6 hours. Even though he'll have to come back again to tune the EQ, I feel like I have a whole new control room. The low end response is way better and my room feels a lot more spacious and natural sounding with some of the bass traps removed. I especially noticed the high end sounds smoother. I feel like I'm listening to music in a room now and not inside of giant headphones. It was a lot of money, but I think the results will far exceed any improvements I could have made to my recordings with micrphones, preamps, compressors, etc. So compared to a nice piece of gear, it really wasn't that expensive.

With all due respect to both Glenn and Ethan, one thing I learned is that you don't need to add 20 traps to a room to make it sound good. You only need to add traps if you need traps. Knowing how many you need is really dependent on the unique qualities of each room. Finding the sweet spot can be a tricky balancing act. Based on what I experienced with my control room, I think I'm going to try removing a bunch of the corner traps I have in my live room and see if the low end improves. I'm also going to try placing those two available Mondo traps on the ceiling over my drum riser? Ethan--any recommendations for hanging those on the ceiling?

Brad
Old 9th March 2009
  #15
Gear Nut
 

Thanks alot for sharing your experience. The one thing that I find particularly interesting is that in the end you removed traps rather than added. I always thought, at least in the CR, that more traps the more even the response.
Old 9th March 2009
  #16
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BradM's Avatar
Yeah that's what I had thought too. I think the only thing that more traps guarantees is that you absorb more and thus shorten your decay times. But having short low frequency reverb times doesn't necessarily mean flat frequency response. The frequency response is dependent on a multitude of variables including room shape, construction, speaker position, listener position, acoustic treatment, gear/furniture placement, etc.

Brad
Old 9th March 2009
  #17
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Weasel9992's Avatar
 

Great post Brad. It highlights a very important point: positioning is key. It's very, very important to place yourself in the best spot in the room before treating it so that you know what issues you really need to tackle. After all, there's no use it hammering a 60Hz null if you can nearly eliminate it purely through positioning, is there? That said, there will always be something to deal with, but it's a lot easier to deal with it if you can minimize the biggest problems and target the smaller ones.

Frank
Old 9th March 2009
  #18
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BradM's Avatar
Exactly.

I should also mention that had my room been more rectangular or my setup more symmetric, then my trapping needs would have been totally different. Due to my asymetry we found that every time we removed or added a trap to the right side of the room it affected the left speaker positively and the right speaker negatively. Conversely the opposite was true as well. It was like acoustic whack-a-mole. heh

Brad
Old 9th March 2009
  #19
Gear Guru
 
Glenn Kuras's Avatar
Quote:
With all due respect to both Glenn and Ethan, one thing I learned is that you don't need to add 20 traps to a room to make it sound good. You only need to add traps if you need traps. Knowing how many you need is really dependent on the unique qualities of each room.
Honestly Brad this is the reason we like for our customers to move in stages. I still believe with the right bass trapping (kind that absorb more lows then highs like the Monster trap)it can't be over done (as in giving less bass) but if the traps are not set right in the room you can actually cause problems that you did not have before.

BTW that is a great report. thumbsup
Old 9th March 2009
  #20
Gear Guru
 
Glenn Kuras's Avatar
Brad,

You might find this report Frank did on treating his room interesting. Kind of went through the same process as you, but started with a empty room.
link: GIK Acoustics
Old 9th March 2009
  #21
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BradM's Avatar
Cool! I'll check out that report. Moving in stages is definitely a good way to go. An even better way to go if you have the money (and not the time) is to just hire a professional to help you through the process.

In the past couple years I've spent weeks of my time hanging bass traps, moving bass traps, measuring my room, moving my speakers, measuring my room some more, and even building a new control room. In the end I got the most successful results from just hiring a professional to "make it happen." It was definitely good to have that arsenal of GIK and Real Traps on hand to quickly arrive at the end result.

Brad
Old 9th March 2009
  #22
Gear Guru
 
Ethan Winer's Avatar
 

Lightbulb

Great report Brad. I feel almost as if I had been there.

I tend to prefer more traps rather than fewer, but a lot of our customers are working in bedrooms where you really cannot overdo it. I didn't notice CR dimensions in your post, but I'll guess it's bigger than 10 by 12 by 8 feet. heh

That said, when you have the time and knowledge (ie: Bob comes in person with test gear) you can be more intelligent about trap placement. I don't think traps in less effective places do any harm, but they may have less benefit than traps in "better" locations. This article shows a good way to find where a fewer number of traps can be placed for the most benefit:

Pink noise aids placing bass traps

Quote:
Ethan--any recommendations for hanging those on the ceiling?
Assuming you have standard MondoTraps, not the HF type, they are more suitable in corners away from overhead microphones. Over a drum set you want broadband absorption that absorbs mid and high frequencies as well as bass. At least assuming a ceiling less than 12 feet high.

--Ethan
Old 9th March 2009
  #23
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BLueROom's Avatar
 

Awesome report Brad! Some very cool insights!

Glenn, look for an order from me soon I need some additional bass trapping in my live room.
Old 9th March 2009
  #24
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Glenn Kuras's Avatar
Quote:
I don't think traps in less effective places do any harm, but they may have less benefit than traps in "better" locations.
For corners YES, but for wall surface you can create a problem if 2 side reflections where countering each other. It does not happen all that much, but can happen from time to time.

Glenn
Old 9th March 2009
  #25
Gear Guru
 
Ethan Winer's Avatar
 

Lightbulb

It's not only side-wall reflections that can combine to make the response "better" than when one surface is untreated. But as you say this is rare, and is easily solved. Further, the issue is not that there's too much bass trapping, but just a weird "stars are in alignment" kinda thing. heh

--Ethan
Old 9th March 2009
  #26
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BradM's Avatar
Quote:
Originally Posted by Ethan Winer View Post
Assuming you have standard MondoTraps, not the HF type, they are more suitable in corners away from overhead microphones. Over a drum set you want broadband absorption that absorbs mid and high frequencies as well as bass. At least assuming a ceiling less than 12 feet high.

--Ethan
Yeah I have the standard ones. Would I be better off just using something like a 2" fabric covered 703 panel instead? My thought was to place it above drum overheads. The ceiling is about 11 feet high. The HF absorption of the MondoTraps looked pretty decent though.

FWIW, before Friday I had all my traps in the recommended "best" locations: front and rear wall corners, front ceiling/wall corners, etc. Having some of those traps there really did make my low end response wonky. But I think that's a function of the crazy room I have and the asymetry. If I had started with a rectangular box room then the results may have been more predictable.

thanks,
Brad
Old 9th March 2009
  #27
Gear Maniac
 
AnthonySpinali's Avatar
 

Brad,

After your experience, do you feel like the Real Traps or the GIK traps are significantly better than the DIY traps that people make on this site? If you don't feel comfortable telling me in public, knowing there are reps from both companies here, you can pm me... I'm just curious if you or Bob thought the professional traps were a lot better.

Your description of the experience was awesome. By the way, what's "a lot of money?" How much does that service cost? I understand if you can't say... I really respect your candid and honest description of the experience.
Old 10th March 2009
  #28
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Seamus TM's Avatar
 

Quote:
Originally Posted by AnthonySpinali View Post
Your description of the experience was awesome. I really respect your candid and honest description of the experience.
Indeed.
Old 10th March 2009
  #29
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BradM's Avatar
Quote:
Originally Posted by AnthonySpinali View Post
Brad,

After your experience, do you feel like the Real Traps or the GIK traps are significantly better than the DIY traps that people make on this site? If you don't feel comfortable telling me in public, knowing there are reps from both companies here, you can pm me... I'm just curious if you or Bob thought the professional traps were a lot better.

Your description of the experience was awesome. By the way, what's "a lot of money?" How much does that service cost? I understand if you can't say... I really respect your candid and honest description of the experience.
I have a number of DIY traps in my studio made from 703 and mineral woodl and not once did Bob comment that I should swap out all my DIY traps for product X, Y, or Z. Of course each product will have its own unique performance characteristics, but they all have their place. Knowing which trap to use where (if at all) comes from a lot of experimentation and experience.

I think Real Traps are exquisitely made traps...especially with their metal frames. The attention to detail in the construction is top notch. However, you pay top dollar for that. The (non-elite) GIK traps are a little more utilitarian in their construction, but they still look good and perform very well. I personally prefer the standard GIK panels because I like their price tag. Buying a bunch of insulation to hang on the wall is not a fun purchase. In my mind the GIK's offer the most bang for the buck. If I was trying to impress celebrity clients and major record labels I might have a different opinion, but that's not the world I live in. If you have the time and motivation you can easily make your own traps that perform admirably for very little money. It all depends what your priorities are.

Feel free to visit Bob Hodas Acoustic Analysis and contact Bob for a quote. Let's put it this way. The service will cost you less than the majority of the Real Traps Room kits.

Brad
Old 10th March 2009
  #30
Gear Guru
 
Glenn Kuras's Avatar
Quote:
Originally Posted by Ethan Winer View Post
It's not only side-wall reflections that can combine to make the response "better" than when one surface is untreated. But as you say this is rare, and is easily solved. Further, the issue is not that there's too much bass trapping, but just a weird "stars are in alignment" kinda thing. heh

--Ethan
Agreed
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