Suck Out Fixed. i think.

[Mike Lavigne]

my room designer designed a whole ceiling bass trap into my room. it was 15" deep and covered the whole 21' x 29' ceiling. except for -6- inset 6' x 8' chambers. these chambers had fabric covered vertical openings with Corning 709 fiberglass in the openings. you can see the chambers in the ceiling of my room pictures. the idea was that this bass trap would control the bass; but clearly in retrospect it was a huge mistake. now 11 years later that mistake has been rectified.....finally.



4 years ago I did have a contractor remove the fabric panels from 4 of the 6 chambers and glue and screw 3/4" finished maple plywood over these openings; which did improve the bass response. I thought that fixed my issue. I was wrong.

last May, 14 months ago, my speaker designer was here for 2 days to do the final tweaking to my Evolution Acoustics MM7's. when he measured the room he found a fairly wide -12db suck out at 30hz, one that the room dimensions did not logically predict. he strongly suspected that the remaining openings in those center chambers were the likely cause. since the MM7's are so powerful and adjustable, he was able to minimize the effect of the suck out with adjustments, but at the cost of ultimate performance. he did strongly suggest I get those openings covered. he even gave me two sets of settings sheets for the 4 sets of adjustments (2 sets on each bass tower).......one for the 'compensated' adjustments he made, and another for 'flat' adjustments anticipating my getting those openings sealed up.

since last May I have given a good amount of effort into finding a contractor to do that work, but was not successful.

then this spring I went thru the experience with the fabric treatments that really took things up a few notches. I had quite a few people thru the room and the feedback was very positive. I knew that somehow I needed to do this final thing and hopefully that would allow the bass performance that was already amazing to go to the optimal level. I was fully motivated to get this done with my excitement from the big step forward from the fabric treatments.

I realized if I wanted to get this done i had to do this myself.

finally I was able to convince my son (I bribed him by giving him one of my bicycles) to help me do this nasty job. I spent last week buying -3- 4' x 8' sheets of finished 3/4" maple plywood, another 8 foot step ladder (we would be working at 10'-11'), a good quality circular saw, saw horses, and all the other bits and pieces we would need. my son had a 208 mile one-day STP (Seattle to Portland) bike ride on Saturday and did not get home till late, so Sunday morning a spent 2 hours clearing out the room.....everything to the sides....racks moved, tape decks moved. big job. tarp laid. ladders set up. neither of us are carpenters; could we rip the panels without chipping? could we even cut a straight line?

would it actually make a positive difference?

we did not know exactly how we would remove the fabric panels or how they were attached. would we be able to get them out without removing the trim pieces? we did not posses the skills to properly replace the trim.

he showed up around 10:30am and we first removed the 8 deflector panels with in the chambers and then got to work pulling off the fabric panels, 4 per chamber, 8 total. we were able to get them out with considerable caution and effort without disturbing the trim. then we measured and started ripping the sheets and cutting to size. I had a work commitment mid afternoon for 2 hours, and returned. finally about 9 that night we screwed and glued the final plywood sheet. then he left and I spent 2 hours reassembling the room. I'd had a listening visitor from California the previous day (HiFi Guy) and then the previous night I'd had a work dinner till midnight. I'm not a young guy. I was gassed. I tried to listen. was it boomy sounding? if that 30hz -12db suck out was solved to a significant degree that old set-up would cause the lower bass to be boomy. I thought it was boomy but fell asleep right away. the next morning before work I was not yet recovered enough to listen.

finally after work that night I had recovered enough to listen and went thru my digital listening references and the lower bass was clearly boomy, if not quite a bit more energetic sounding. I had spoken to my speaker designer earlier and he said I should shut off the amps in the bass towers and see if it sounded clean. if it did that indicated that the closing of the openings had not likely caused other issues. I did that, went thru my references again, no problem, sounded very clean. so then I turned the bass towers back on and adjusted both the 'bass level' and the 'bass quality' (Q) halfway to the 'flat' positions and listened to the references again. better, less boomy. much more energy. some magical things happening. then I went 3/4 to the flat positions and again listened. now it was a big WOW! everything was now at a whole new reference level. all up and down the frequency range. a whole new level of coherence and naturalness. vocals were superb sounding. much more holographic. bass impact a couple orders of magnitude better. so I just listened late until early morning Tuesday and again after not much sleep in the morning. I was stoked.

that night I first listened as it was; then found a good cut and moved the 'bass quality' the last little bit to the flat position. clearly better. then I moved the 'bass level' the last little bit to the flat position and it was super clean and right. it sounds perfect to me now; I've been listening for 2 days now to it and I'm just beside myself. as good as it had been; it's not only much better but much different than even Saturday night. what is so crazy to my mind is how much different vocals and the mid range is simply by eliminating a 30hz suck out. it was very interesting hearing how much detail had been covered by those adjustments which were pegged to cover the suck out when taken to flat all that detail jumped out.

the MM7's are now fully unleashed and are something to behold!

how close to absolutely flat is it? don't know. I hope it can get better from here.....but maybe not. is the suck out all the way gone? once I measure it I may or may not post it. we all know how much I love graphs.

I suppose I have a persecution complex posting about discovering my personal mistakes. I know from time to time that comes back to haunt me when ner-do-wells want to give me some crap. but so what. I feel that these sort of experiences contribute to the collective knowledge. and one has to be open to learning and going farther down the road.

my goal 11 years ago with my efforts was to get the room and system out of the way of the music; I think I've essentially done that finally.

oh and btw, this job cost me about $250 in materials and I did acquire approx. $450 worth of tools and a ladder. I was going to give the bike to my son anyway but he did not know that. so between the fabric and this job about $500-$600 and the effect is off the charts.

[a.wayne]

Good show Mike , i'm always impressed by your approach to improve your already serious setup , as I'am about your son doing 208 miles in one day, my max when I was an avid cyclist was 120 KM , more was a bit too much for me ..


Your room and system is truly beautiful Mike ...

Congrats ..

[Mike Lavigne]

Good show Mike , i'm always impressed by your approach to improve your already serious setup , as I'am about your son doing 208 miles in one day, my max when I was an avid cyclist was 120 KM , more was a bit too much for me ..

thanks.

approximately 1500 of the 10,000 riders on the 208 mile STP do it in one day. he started at 4:45am and ended at 9pm. he did have a mishap early in his ride where he was looking back and touched a curb with his wheel. this ended up breaking spokes and causing a wobble. but the great thing about a group ride is that he did get help and was able to repair it sufficiently to finish. but the problem followed him all day.

this Saturday he is doing The High Cascades 100 and then next Thursday he is doing the 2015 RAMROD Ride Around Mt. Rainier.

he was able to find a new set of wheels to replace the damaged ones for his road bike for the RAMROD.

if he can pull off that trifecta my hat will be off to him. this is a new sort of thing for him on the bikes this year.

[Peter Breuninger]

thanks.

approximately 1500 of the 10,000 riders on the 208 mile STP do it in one day. he started at 4:45am and ended at 9pm. he did have a mishap early in his ride where he was looking back and touched a curb with his wheel. this ended up breaking spokes and causing a wobble. but the great thing about a group ride is that he did get help and was able to repair it sufficiently to finish. but the problem followed him all day.

this Saturday he is doing The High Cascades 100 and then next Thursday he is doing the 2015 RAMROD Ride Around Mt. Rainier.

he was able to find a new set of wheels to replace the damaged ones for his road bike for the RAMROD.

if he can pull off that trifecta my hat will be off to him. this is a new sort of thing for him on the bikes this year.

Mike,

Your son should be congratulated. That is a long ride.

My longest single ride was 115 miles. Does your son road race?

My best,

Peter B.
btw, congrats on the room.

[Mike]

Mike - your attention to detail and efforts in room treatments is nothing short of spectacular. I would love to hear the big MM7's with Dart. Jonathan must love your room!

Mike, what are the approximate dimensions of your room?

[still-one]

Mike
Nice write-up. Did you cover the ply-wood with fabric to match the decor in your room or will you end up painting it? Maybe I am missing something, were the angled units put back up again after the plywood was installed.

[the professor]

Congrats on bettering an already great room.

[CPP]

Mike what a great room.

[Mike Lavigne]

Mike
Nice write-up. Did you cover the ply-wood with fabric to match the decor in your room or will you end up painting it? Maybe I am missing something, were the angled units put back up again after the plywood was installed.

Jim, thanks.

yes; those angled panels were put back up after we installed the finished plywood.

in the picture taken last week before the work you can see the grey color of the fabric on the sides of the angled panels. that surface is now finished maple. 4 years ago the I removed the fabric panels from those other 4 inset chambers and covered them in the 3/4" ply and so they are now the same maple finish as these panels. they all match.

[Mike Lavigne]

Mike - your attention to detail and efforts in room treatments is nothing short of spectacular. I would love to hear the big MM7's with Dart. Jonathan must love your room!

Mike, what are the approximate dimensions of your room?

my room is 21' x 29' x 11'. it is essentially an oval shape with angles and a room built inside a room.

[Mike Lavigne]

Mike,

Your son should be congratulated. That is a long ride.

My longest single ride was 115 miles. Does your son road race?

My best,

Peter B.
btw, congrats on the room.

no; my son does not bike race....yet.

he lives on a sailboat, is a very active back country skier and until recently rode his KTM 1000 motorcycle in the back country a lot.

but he has fought a weight problem all his life and last fall decided to get serious about biking to help him get healthier. he dropped 50 pounds, then put 20 back on. but hopefully with this direction he will keep working at it.

he does not listen to his dad, so I have to hope that he figures it out for himself. lifestyle changes are hard.

[KeithR]

man, you've had some room ordeal Mike. I'm glad you're a step closer to the promise-land...

[socfan12]

Wow, gorgeous room, Mike! Please do post the graphs. I need to measure my room now that I have my acoustic treatments up.

What measuring kit do you have?

Again, well done on the room, sir!

[Mike Lavigne]

Wow, gorgeous room, Mike! Please do post the graphs. I need to measure my room now that I have my acoustic treatments up.

What measuring kit do you have?

Again, well done on the room, sir!

Allen,

thank you for the kind words.

I own a Phonic PAA3 RTA although at this moment it is loaned out to a friend. I have a few offers from other friends who have the right kit to come over and measure. likely I will go that way but not sure I will publish the plots/graphs.....but I might. not sure I want to go thru the monobrow beatdown.

I'm not anti-measuring, and bass performance/set-up is one area where I do firmly believe it actually has real value.

[Mike Lavigne]

update; another step forward.

there are 4 different dials to adjust on each of the 4 separate bass adjustment panels (2 per side) on the bass towers. the OP describes what happened when I adjusted 2 of them for each section; the 'bass level' and the 'bass quality'. I set those to what the designer called 'flat' positions which were quite different (about 40-50% around the adjustment scale) than where they had been in the 'compensated' positions.

we had left the other 2 adjustments (bass filter and bass extension) in the 'compensated' position in case we found that the changes I made did not work, so we did not need to find those positions again.

yesterday I had left a message for the speaker designer asking him if I could also move the other 2 adjustments to the spots he had designated as 'flat' since we did know that we had a positive result from moving the other 2. early last night I had not yet heard back from him and decided 'what the heck' I want to know what that will do, so I did make those adjustments. in this case; both the 'bass filter', which is a variable crossover, and 'bass extension' the 'compensated' positions were much closer to the 'flat' positions. in one of the 4 was already in the 'flat' position.

WHOA! more meat on the bones, more heft in the bass, but it was the fire and sparkle of the mid range that took a significant improvement. vocals were quite a bit better. I had thought I was all the way there on perfect balance of voice and string tone but I was wrong. richer, more harmonic shading, more tube like breath of life.

every reference I have was improved in subtle ways. delicate little things in the soundstage are all more real and filled out and complete. magical.

these were tiny adjustments on 2 innocent dials on the back of some active bass towers that crossover at around 35hz with the main towers. how can this do that? don't know, but they did.

[mep]

Mike-It's great that you are still finding meaningful improvements to your system. Plus, these are the best kind because they don't cost any money-you are just optimizing what you already have. I just went through a round of that last month when Andre came to my house. I didn't spend a penny, but my system sure sounded better from the adjustments Andre made.

[socfan12]

update; another step forward.

there are 4 different dials to adjust on each of the 4 separate bass adjustment panels (2 per side) on the bass towers. the OP describes what happened when I adjusted 2 of them for each section; the 'bass level' and the 'bass quality'. I set those to what the designer called 'flat' positions which were quite different (about 40-50% around the adjustment scale) than where they had been in the 'compensated' positions.

we had left the other 2 adjustments (bass filter and bass extension) in the 'compensated' position in case we found that the changes I made did not work, so we did not need to find those positions again.

yesterday I had left a message for the speaker designer asking him if I could also move the other 2 adjustments to the spots he had designated as 'flat' since we did know that we had a positive result from moving the other 2. early last night I had not yet heard back from him and decided 'what the heck' I want to know what that will do, so I did make those adjustments. in this case; both the 'bass filter', which is a variable crossover, and 'bass extension' the 'compensated' positions were much closer to the 'flat' positions. in one of the 4 was already in the 'flat' position.

WHOA! more meat on the bones, more heft in the bass, but it was the fire and sparkle of the mid range that took a significant improvement. vocals were quite a bit better. I had thought I was all the way there on perfect balance of voice and string tone but I was wrong. richer, more harmonic shading, more tube like breath of life.

every reference I have was improved in subtle ways. delicate little things in the soundstage are all more real and filled out and complete. magical.

these were tiny adjustments on 2 innocent dials on the back of some active bass towers that crossover at around 35hz with the main towers. how can this do that? don't know, but they did.

Great stuff, Mike. I hear when the bass is right, you really hear it in the mids, and your experience seems to be testimony to that.

[Vapor1]

Regarding taking measurements of the room + speakers, you really need the ability to isolate the two from each other in the data displayed. That means not just Frequency Response data, but also time domain data. You need to be able to see where the room is storing energy in order to address those areas properly. That Phonic RTA you have Mike is better than most RTA's in that it shows RT60's, but 1/3 octave in the bass is borderline enough resolution. Take a look at the Dayton Omnimic, it's inexpensive and very easy to use, and has much more functionality.

[a.wayne]

The reason why you perceive an improvement in the mids is because when the bass is wrong it affects the overall tonal balance, correcting it, improves the tonal balance and this is perceived as better midrange, voices , instruments , Piano, everything is more natural sounding.

The Bass affects the sound of almost every known instrument to man..


Regards.

[Mike Lavigne]

The reason why you perceive an improvement in the mids is because when the bass is wrong it affects the overall tonal balance, correcting it, improves the tonal balance and this is perceived as better midrange, voices , instruments , Piano, everything is more natural sounding.

The Bass affects the sound of almost every known instrument to man..


Regards.

+1.

agree completely.

the part that floored me was the tiny change i made, and that the bass towers cross over under 40hz, around 35hz. how a very slight degree of more linear deep bass matters so much.

[a.wayne]

Yep and why i chuckle whenever I see limited bandwidth speakers being pushed as SOTA ....