PLYWOOD vs MDF For Speaker Building - Tests Show Surprising Results

Comments · 528

• IB

  @IBuildIt · 5 years ago (edited) · pinned

  NOTE: This is to clear up some confusion over what I meant about bracing and damping:<br>Speaker building was always bracing and damping. But at some point the idea started that bracing alone was better, just using a lot more of it. Guys were still doing the traditional bracing and damping (like me), but you also started seeing these bracing only builds happening. The idea was to drive up the panel resonance high enough so that it wouldn&apos;t be excited and therefore wouldn&apos;t be a problem<br>I&apos;m speaking 100% from a DIY standpoint, not from what the major manufacturers were doing.<br><br>Will making the entire box from the same material make a difference? Possibly, but I did what I could to take the rest of the box out of the measurement. For example the box was clamped down to my very heavy and stable workbench to keep it as stationary as possible, and help restrict the measurement to the panel itself. Yes the other panels were still vibrating and in turn that can affect the panel being tested, but it&apos;s the same for each of the different panels.<br>Each panel was exactly the same size - 8-1/2&quot; x 12&quot; with the screw holes in exactly the same places. <br>Why 30Hz to 2000Hz? I did some &quot;warmup&quot; testing prior to the measurements I made to determine the best range that shows the most relevant data. 30Hz because the speaker I used doesn&apos;t have significant output below 30Hz. <br>I used my ACH-01 accelerometer connected to REW to run the measurements. I made a special preamp for that &nbsp;accelerometer in this video: <a href="https://www.youtube.com/watch?v=o1Fctgs8CcQ">https://youtu.be/o1Fctgs8CcQ</a><br><br>My conclusions are that the material used is not a significant factor in how the speaker will sound. As long as what you are working with is of reasonable quality, you should not be able to hear the difference. <br>You may be able to imagine you hear the difference, though, and the human psyche is a powerful thing to overcome. If you believe MDF sounds dull and sluggish, and Baltic birch plywood sounds lively and fast, then it&apos;ll be very difficult to get past that and you should use the one you think will sound best.<br>As for bracing vs damping, I think both are valid. Use bracing to reduce panel size so that the damping will be more effective. The rationale of those that prefer bracing alone is that the damping &quot;smears&quot; the response. Much like above, it&apos;ll be hard to get past this idea if it&apos;s what you believe, so best to go with what you think is better way.

  82

• MU

  @murphyjanitorial · 2 years ago

  The most incredible part of the whole video is that he found a piece of Baltic Birch 😮

  33

• BR

  @BrianLevine-q7e · 2 years ago

  I remember that sound. I worked at Allison Acoustics in the &apos;80&apos;s. Started out doing production. Worked my way up to testing. We tested components and finished speakers. Our cabinets were MDF with a fake veneer on the outside. Inside we placed a small amount of fiberglass.Never used isolation rings on the speaker basket or bracing. Dr. Roy had the cabinets made to his specs. Never tested cabinets. Interesting show.

  8

• TO

  @tomaslainas695 · 5 years ago

  back when i studied sound engineering and was into speaker building, my conclusion was the material is not as important as the construction. meaning adding bracing reduced resonance

  147

• BA

  @Barneyrubble241 · 2 years ago

  About 40 years ago a friend of mine had his brother build him a pair of speakers. The cabinets were plywood and the drivers were from Radio Shack. &nbsp;They stood about 3 feet tall, 2 feet wide and a foot deep. To this day they are the best sounding speakers I&apos;ve ever heard. I need to ask him if he still has them. My guess, the drivers have turned to dust by now, but it would be a cool re-build with modern drivers.

  22

• IS

  @isaeagle4031 · 5 years ago

  Your findings are very accurate. Bracing helps more than dampening, but both are useful and necessary. Dampening will reduce the amount of energy reflected back into the cone. Bracing raises the resonant frequency of the panels.

  23

• GR

  @GregsGarage · 5 years ago

  I&apos;m enjoying this whole series John. &nbsp;We used to spend hours in the warehouse A/B comparing all kinds of things. &nbsp;One of the breakthrough days was when we got a crossover that could time align the drivers in a horn loaded array... &nbsp;The pressure level differences were quite notable.

  20

• ST

  @sthenzel · 5 years ago

  Ages ok (mid-80s, I guess), a friend of mine had an old pair of speakers, something from the 70s, pretty standard stuff, just like the rest of the equipment.<br>The drivers had paper cones with stiff suspension, the soft &quot;rubber&quot; wasn´t really standard at the time those were made.<br>Those speakers were ok, but down low their resonance made them sound quite undefined.<br>After a little thinking about it, we removed the drivers, measured the inside dimensions and cut a few pieces of wood, about a 16th oversize, wedged them between the centers of the panels and remounted the drivers.<br>The low bass got much better, it sounded much more responsive and defined.<br>It still was far from comparable with higher-end contemporary stuff, let alone modern equipment, but it was definitely an improvement.

  10

• IB

  @iberiksoderblom · 6 months ago

  In the late 80&apos;s, early 90&apos;s we used to laminate the panels from two types of wood, that be MDF and a plywood type, chosen to cancel out any peak frequencies.<br>The front baffel was then felt and suede covered.<br>All corners rounded, also internally.<br>The box designs where shaped like a D if you looked from above, with the widest part of the D where there was the higest pressure inside the cabinet (meassured with a bass sweep).<br>The D-shape was more narrow at the top to prevent any parallel sides.<br>We tried a couple of concrete types as well, but it was extremely labour intensive (made in two halfs, glued together) and ringing could be an issue, depending on concrete types.

  2

• MA

  @markpalmer3071 · 5 years ago

  Probably already commented on, but my guess is MDF is used mostly because it&apos;s always flat and takes less work to finish for painting/wrapping. Great video!

  29

• CM

  @cmick09ish · 4 years ago

  you are the only other person besides myself who seems to be aware that mood has a very real effect on how &quot;tone&quot; or anything really is perceived. Do only the Snake oil salesmen know this too? haha

  2

• ER

  @erics.4113 · 5 years ago

  Cool vid man. Thx for taking the time to build the experiment and edit down to such a pleasurable video. Man of many talents. I think I say that every time I watch something you put out. Lol

  4