Diffuser Panel COVID Project

[Tarheel TJ]

I thought y'all might like to see my recently completed COVID project.  A few years ago, I added some absorbtion panels to my listening room/home theater.  I did 4" thick panels on the sidewall first reflection points and behind the speakers.  Did some 2" thick "cloud" panels on the ceiling.  It made an absolutely colossal difference in perceived sound quality.  Easily as significant as a major component upgrade.  It did make me wonder, however, if doing something on the wall between the speakers would help with imaging, soundstage, etc.  The absorbtion panels did deaded the sound of the room quite a bit, however, and I was concerned about going too far.  So this time, I wanted to try some diffuser panels instead.

   I found some plans for skyline style diffusers and thought they looked really cool and would fit the bill perfectly.  Given the new realities of a COVID afflicted world, I found myself with a bit more time for at-home projects, so I decided to give it a go.  Little did I know just how much time and effort it would take.  In the end, I am extremely pleased with the results, so I though I'd show off a bit.

[Tarheel TJ]

In the end I had to cut, sand, paint and glue over 1000 individual blocks (16x16 per panel, 4 panels).  I probably have somewhere north of 60 hours in this in total, but I think it turned out great.  I was going for a land/sea or ground/sky sort of theme with the colors.  I think it looks great.  Definitely improved clarity and imaging of the system as well. 

[Toz]

That looks on par with a good avant garde art show piece.  They have that mid century architectural look, it's really good! Your speakers look great too. Could you elaborate a little on the speakers? What's up with the milk jugs on the floor?

[Khornukopia]

Your panels look good. The different shades of color give a nice emphasis on the depth. Turning each panel 90 degrees created an interesting pattern. 

[Tarheel TJ]

1 hour ago, Toz said:

That looks on par with a good avant garde art show piece.  They have that mid century architectural look, it's really good! Your speakers look great too. Could you elaborate a little on the speakers? What's up with the milk jugs on the floor?

 

Thank you for the compliment!   That is definitely the look I was going for.

 

The speakers are 2-way fully active with a La Scala Industrial bass bin (refinished).  The top horn is the ZXPC 11"x17" horn, available on eBay.  I am using B&C De-750TN 2" compression drivers.  A MiniDSP 4x10HD does the crossover/DSP duty.  There is also a Bill Fitzmaurice THT horn sub in the corner, under the sailboat and reel to reel deck.

 

The milk jugs are my supply of distilled water that I use in my ultrasonic record cleaner (from cleanervinyl.com).

[moray james]

Tarheel TJ would you comment on your impressions when you got your four large diffusors installed? They were obviously a lot of work. They do look very nice and make a very nice visual statement, that said sonically were they worth the effort in your opinion?

[babadono]

Nice work. I like.  So 2 x2 staggered lengths? Only glue to fasten blocks to backing? Only 60 hours? That'd take me a couple hundred.

[Tarheel TJ]

    There was definitely an improvement in the sound.  It is a touch less harsh and a little more detail is audible.  Not too dramatic.  I would imagine this effect would be more pronounced in a room that was not already extensively treated with absorption, as mine is.  The biggest difference by far is the improvement in imaging and soundstage.  Before, it often sounded more like the music was coming from the speakers themselves, not the space in between.  Now there is a more continuous sound field all the way across the front wall.  I would say there is more depth to that sound field as well.  Overall, I would say the absorption panels made a more dramatic effect than the diffusers, but both made an improvement.

   As to whether it was worth the time or not is a question I guess you'd have to answer for yourself.  I look at hi-fi as a hobby to spend time on, not just a way to spend money.  I bought my LaScala Industrials in a very sad state.  The cabinets smelled like beer and cigarettes and the tweeters were missing.  I spent many hours refurbishing them and was very happy with the end result (though I only use the bass bins now).  Likewise, I built a Bob Latino ST-70 a couple years ago from a kit, when I could have bought an already assembled amplifier.  To me, the time spent and the satisfaction of building something for yourself brings as much joy as listening to the result.  The fact that these are nice to look at just adds to the enjoyment.

[Tarheel TJ]

8 minutes ago, babadono said:

Nice work. I like.  So 2 x2 staggered lengths? Only glue to fasten blocks to backing? Only 60 hours? That'd take me a couple hundred.

 

Actually the blocks were more like 1 3/8" square.  They are pine staves from Home Despot.  Like what you would use between your deck and the railing.  Glued to 1/2" plywood that I had laying around.  With the glue and 12 cans of spray paint, I probably have a little over $100 in them.  By far the worst part was sanding the ~1000 wood blocks.  Took sooooo long.

[Tarheel]

Looks great.  Would like to hear your system!

[babadono]

Well he's a Tarheel too. So maybe he is close(enough) to you

11 minutes ago, Tarheel said:

Looks great.  Would like to hear your system!

 

[Tarheel TJ]

15 minutes ago, Tarheel said:

Looks great.  Would like to hear your system!

 

Send me a message any time you are in Winston-Salem! 

[Tarheel]

4 hours ago, Tarheel TJ said:

 

Send me a message any time you are in Winston-Salem! 

And if you ever get to Wilmington!

[Lbk]

On 2/9/2021 at 9:18 AM, Tarheel TJ said:

In the end I had to cut, sand, paint and glue over 1000 individual blocks (16x16 per panel, 4 panels).  I probably have somewhere north of 60 hours in this in total, but I think it turned out great.  I was going for a land/sea or ground/sky sort of theme with the colors.  I think it looks great.  Definitely improved clarity and imaging of the system as well. 

Thought about doing some diffusers a couple years. Looked thur the plans and decided I didn't have patients, more complicated than people realize. Great job, looks good! 

 

I am using the same zxpc horns on my chorus II, 3 way. I found it be a nice inexpensive upgrade.

[Tarheel TJ]

I have to say, after spending a great deal of time listening over the weekend, I think I may have under-estimated the difference these have made to my listening room.  I heard some really nice detail and spaciousness to the sound.  This may be more of an improvement than I initially realized.  Good stuff!

[Lbk]

Have you run your horn's / speakers passive?

[Tarheel TJ]

7 minutes ago, Lbk said:

Have you run your horn's / speakers passive?

 

I have run these speakers in a number of configurations.  At first, they were stock La Scalas with AL-3 crossovers.  The only non-stock thing about them was that I removed the tweeter from the enclosure in order to time align it.  I then ran this same configuration for a while with the K-400 horn replaced with the ZXPC horn (using stock K-55 with a 1"-2" adapter).

 

The real revelation, however, was going to a 2" exit driver (B&C De-75-TN) and a fully active DSP crossover.  The performance gains are off the charts.  I would never consider going back to a passive crossover at this point.

 

[Lbk]

12 hours ago, Tarheel TJ said:

 

I have run these speakers in a number of configurations.  At first, they were stock La Scalas with AL-3 crossovers.  The only non-stock thing about them was that I removed the tweeter from the enclosure in order to time align it.  I then ran this same configuration for a while with the K-400 horn replaced with the ZXPC horn (using stock K-55 with a 1"-2" adapter).

 

The real revelation, however, was going to a 2" exit driver (B&C De-75-TN) and a fully active DSP crossover.  The performance gains are off the charts.  I would never consider going back to a passive crossover at this point.

 

I have been thinking about going active for awhile. I liked going to a 2 inch horn, made a big difference. Running my horns straight off the chorus II xovers right now.

 

Can't decide if should go active  for my next upgrade or do sound panels. I leaning towards sound panels first. Any suggestions on which to do first? Thanks!

 

[Tarheel TJ]

     Well I know one thing, you are in for a treat!  Going fully active with DSP and treating my room with absorption/diffusion are unquestionably the two largest upgrades I have ever made to my system.  Do both of those things and you will surely ascend to a higher plane of audio existence, haha.

     My initial reaction is to say go active first, simply because it is such a powerful tool.  You really can make your system sound exactly the way you want it to.  You will have control over frequency response and phase in ways you never imagined possible.  It truly puts you in the drivers' seat of your system.  It also opens up a new world of upgrades and DIY tinkering.  You can essentially swap individual speaker components at will, using the DSP to knit everything together.  None of this is even remotely possible with passive components.

   However, I think you actually have the right idea with doing panels first.  There are two reasons for this.  First, it is an immediate and very noticeable upgrade.  Your system will sound much better as soon as you hang the panels, and you will gain the added enjoyment right away.  Setting up a DSP crossover takes time.  These systems are powerful and have impressive capability, but they are only as good as the person programming them.  It took me well over a year just to figure out how to set up crossovers and properly EQ a system.  Don't get me wrong, I had it up and running and sounding pretty good in a day or two, or so I thought.  To really get it dialed in, you will have some learning to do.  I am only now beginning to learn about how crossovers effect phase response, and some strategies to address this (see Subconscious auditory effects..... ).  Additionally, having a well-treated room will help you make better measurements of your system's response, which is a critical part of optimizing a DSP crossover.

    So, if I were you, I'd do some sound panels first.  Do a mix of absorption and diffusion if you can, but do absorption for sure.  Try to cover as much surface area as you can stand.  One or two panels will probably not get the results you are looking for.  Try behind the speakers, side wall first reflection points and if possible, ceiling.  You will reduce the reverb time of your room and increase the proportion of direct sound.  This will be a very noticeable improvement.  Then, after you have enjoyed that for a while, take the leap and go active/DSP.  You'll have a nice-sounding, low-reverb room in which to start measuring and tweaking.

 

[Lbk]

2 hours ago, Tarheel TJ said:

     Well I know one thing, you are in for a treat!  Going fully active with DSP and treating my room with absorption/diffusion are unquestionably the two largest upgrades I have ever made to my system.  Do both of those things and you will surely ascend to a higher plane of audio existence, haha.

     My initial reaction is to say go active first, simply because it is such a powerful tool.  You really can make your system sound exactly the way you want it to.  You will have control over frequency response and phase in ways you never imagined possible.  It truly puts you in the drivers' seat of your system.  It also opens up a new world of upgrades and DIY tinkering.  You can essentially swap individual speaker components at will, using the DSP to knit everything together.  None of this is even remotely possible with passive components.

   However, I think you actually have the right idea with doing panels first.  There are two reasons for this.  First, it is an immediate and very noticeable upgrade.  Your system will sound much better as soon as you hang the panels, and you will gain the added enjoyment right away.  Setting up a DSP crossover takes time.  These systems are powerful and have impressive capability, but they are only as good as the person programming them.  It took me well over a year just to figure out how to set up crossovers and properly EQ a system.  Don't get me wrong, I had it up and running and sounding pretty good in a day or two, or so I thought.  To really get it dialed in, you will have some learning to do.  I am only now beginning to learn about how crossovers effect phase response, and some strategies to address this (see Subconscious auditory effects..... ).  Additionally, having a well-treated room will help you make better measurements of your system's response, which is a critical part of optimizing a DSP crossover.

    So, if I were you, I'd do some sound panels first.  Do a mix of absorption and diffusion if you can, but do absorption for sure.  Try to cover as much surface area as you can stand.  One or two panels will probably not get the results you are looking for.  Try behind the speakers, side wall first reflection points and if possible, ceiling.  You will reduce the reverb time of your room and increase the proportion of direct sound.  This will be a very noticeable improvement.  Then, after you have enjoyed that for a while, take the leap and go active/DSP.  You'll have a nice-sounding, low-reverb room in which to start measuring and tweaking.

 

Excellent info, thanks! I'm about to finish a pair of exodus anarchy subs, next week I think I will try building some sound panels.

 

I already have the fabric just need some wood panels and roxul. May build some diffusers later, make it a long term project. Not sure I have the patients to do it all at once.

 

May have a temporary idea for active, have a fancy  clarion active xover from car audio days.  ( 12 volt) I've heard computer power supplies can be used to put out 12 volts. Might work till I get around to buying a home unit. Thanks again!