Adding thickness to the material adds stiffness, and adds mass. This is generally an improvement. Adding braces adds stiffness, but not mass. This is also an improvement.Cameron Glendin said:
If you screw a tissue into a ball, then select a stone of the same size then throw them, The tissue will lose its energy earliest and fall to the ground.
ShinOBIWAN said:
They are both sold as 3/4" mdf.... thickness varies from manufacturer to manufacturer and is all over the map.
Our home building industry works in imperial units -- 2x4s, 2x6s, etx (actually ~1.3x3.5" and 1.5x5.5") and 4x8 sheets of OSB, plywood, and gyproc.
Cabinet industries (like were Chris works) are metric.
dave
Because the boxes i built the way i do sound better than a box built with MDF. I push box resonances up high enuff, and with a large enuff Q that they just don't get excited giving me a box with better downward dynamic range -- an MDF box tends to store energy & pass back some of it later in time mooshing the tiny low details.
To my mind the wole MDF thing is a myth perpetrated by commercial speaker manufacturers so they could use a cheaper raw material -- cheaper to start with, to machine, to finish (the only part that isn't cheaper is to ship it). They have done such a good job even a lot of speaker manufacturers believe it. In some ways it was easy... MDF is thicker & heavier, and therefore appeals to the whole bigger is better mindset.
dave
To my mind the wole MDF thing is a myth perpetrated by commercial speaker manufacturers so they could use a cheaper raw material -- cheaper to start with, to machine, to finish (the only part that isn't cheaper is to ship it). They have done such a good job even a lot of speaker manufacturers believe it. In some ways it was easy... MDF is thicker & heavier, and therefore appeals to the whole bigger is better mindset.
dave
planet10 said:
Really? I've never seen a commercial speaker made with MDF, only particle board, which is lower grade and about the same density as plywood. Are the higher end commercial speakers made with MDF? Or did MDF for DIY become popular because somebody assumed a higher grade version of what commercial units are built of could only be better?
Well you Aussies, just get yourself a decent piece of solid Jarrah. Tap it, what happens? Thud. If thick enough it is like tapping a brick. Then try tapping a piece of MDF. What happens? Booonnnk. I have used Jarrah in musical instruments along with a whole lot of other timbers and acoustically it is the deadest wooden material I have come across. Very stiff, heavy, and with a high internal damping factor, much more than MDF. It also just happens to be a wonderful furniture timber so looks fantastic when finished nicely. The main problem is it is not all that stable, so you need to allow for movement, but that is not an insurmountable problem. The last speaker I built i made the prototyle from MDF and the final cabinets from solid Jarrah. Quite a noticable difference in sound in favour of the Jarrah. Bigger cabinets might be more difficult because of the amount of movement and weight (and cost), but for reasonable sizes I'm convinced. Solid Jarrah.
Tassie Myrtle is another candidate. Also heavy and non resonant (not as dead as Jarrah), but much easier to work than Jarrah.
Tassie Myrtle is another candidate. Also heavy and non resonant (not as dead as Jarrah), but much easier to work than Jarrah.
Hi,
quite a number of higher end speaker manufacturers have stuck with timber based cabinets choosing birch ply rather than MDF.
Occasionally with a real timber front.
I have not seen a modern (less than 10year old) cabinet in the retail market using particle board.
For robustness PA speakers seem to always go to birch ply rather than MDF, and it's lighter to cart hither and forth.
Bracing is crucial to good bass performance. Panel thickness is almost secondary.
quite a number of higher end speaker manufacturers have stuck with timber based cabinets choosing birch ply rather than MDF.
Occasionally with a real timber front.
I have not seen a modern (less than 10year old) cabinet in the retail market using particle board.
For robustness PA speakers seem to always go to birch ply rather than MDF, and it's lighter to cart hither and forth.
Bracing is crucial to good bass performance. Panel thickness is almost secondary.
planet10 said:
Surely the same thing is possible with MDF, given enough bracing and thickness (thickness raises rigidity, raising the resonance frequency, mass lowers the amplitude). How high do you try and get things realistically? Even tapping a solid block of aluminium, bricks or a tree mades a sound.
noodle_snacks said:
You rap my cabinets they will make a sound... but the energy inside and outside the speaker under normal conditions will not.
I haven't been able to get MDF to do the same thing... well braced 1/2' HDF (medite) was better than anything with MDF bit still not up to plywood.
MDF costs us nothing (literally), we have to pay for plywood, you can be sure i'd use MDF if i could get it to do the same thing and you can be assured i've tried.
MDF is suitable for bases & deflectors & suprabaffles. As well we'll use it for spacers (the 12mm BB, 12mm MDF spacers, 12mm BB walls of the Fonkens are really incredible, but the MDF is more or less interchangable with BB or solid)
dave
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.