Jump to content

Speaker Cabinets


Barden

Recommended Posts

Dense and therefore very rigid materials such as MDF are less prone to exhibiting resonances which can colour the sound. Others will provide a better explanation of resonance but remember the High School physics lab experiment in which a guitar would be placed close to a speaker and when a signal was played through the speaker and its frequency was varied the various strings could be made to vibrate in sympathy ? The same thing occurs in speaker cabinet walls and is referred to as resonance.

Wooden boards have graining which can serve to channel vibration further increasing the tendency to resonate. Plywood reduces this in that the grains are not continuous and are less prone to audible resonance. MDF has virtually no grain and is therefore even less prone to producing audible reonance. This is by no means a statement that an MDF cabinet cannot resonate because they very clearly do because the air within the cabinet will resonate but the use of MDF or plywood reduces the amount of resonance that has to be counteracted in the design of the speaker.

------------------

It is meet to recall that the Great Green Heron rarely flies upside down in the moonlight - (Foo Ling ca.1900)

Link to comment
Share on other sites

IMHO manufacturers use MDF primarily because of cost. I am not aware of any manufacturers that use particle board for quality speakers.

FWIW IMHO MDF is not particularly rigid. In my experience, good plywood is more rigid given the same thickness. MDF is dense and has no grain pattern. IMHO it is primarily the density which makes it good acoustically for speaker cabinets. It is also a superior substrate for veneer, flat and smooth. Unfortunately, it doesn't have much in the way of strength in any direction. It really shouldn't be used anywhere that is subject to impact or stress. Manufacturers can get away with it because they ship via freight companies on pallets. But as other recent threads show, shipping even well packed speakers with MDF cabinets via USPS, UPS or FedEx like most of us are likely to do can be fatal to them.

The old Heritage line speakers were basically made from plywood. I have shipped several sets of Heresys via UPS and USPS without any damage to the cabinets.

Don't know of any Klipsch speakers built from solid wood. Plywood is superior for speaker cabinets in just about every aspect except for trim.

I prefer to build cabinets from void free Baltic birch plywood. All plys are birch unlike American plywood where the core plys are usually something else. It is much denser, and therefore closer acoustically to MDF than typical American plywood. It is also much more expensive.

Link to comment
Share on other sites

MDF is superior to plywood in that it has reduced resonance. Plywood is indeed more rigid, which Increases resonance and shifts it to higher frequency bands, which is undesirable. Plywood is superior in burst strength and for that reason is used in speakers that will see rough handling, such as pro cabinets that are moved from job to job. Also used when the speakers will be "flown" that is hung in the air. The hardware and the wood must be strong enough to support the weight of the speakers so no one underneath is injured by a falling speaker.

Solid hardwood is the most resonant, and most costly of all, making it a bad choice for speakers. There are many grades of MDF each with a different cost and set of mechanical / acoustical properties.

Link to comment
Share on other sites

Weight aside, what about the Norh and other brands of Marble speakers... is that a good material, if youdon't care about cost or the hard work to fabricate the boxes? we just got our kitchen remodeled and we have at least two perfectly good slabs of granite that we are not going to use, enough to make say 15 RF-7's or more, it is a ton of granite. not saying that i want to build granite speakers, but just lets say in theory, would that be a good or bad idea? anyone want some granite? hehe.

------------------

-justin

SoundWise

promediatech@Klipsch.com /1-888-554-5665 - RA# 800-554-7724 ext 5s>

Email Me

Link to comment
Share on other sites

The Krell LAT-1 has these fluted sides on some really stiff housings. So, maybe, if you were to get the granite fluted to act as a difuser soundwaves that hit the cabinets then you may have something there. I hear you can rap your nuckels on a LAT-1 and it's like knocking them on a 3 ton rock.

------------------

Tom's Money Pit

This message has been edited by tblasing on 09-11-2002 at 01:55 PM

Link to comment
Share on other sites

  • 8 months later...

Three questions:

1) What about using 3/8" thick glass as the inside lining, then using 3/8" plywood for the outside finish?

2) How thick of a soild wood, say pine, would you need to equal the density of MDF or 3/4" plywood?

3) What about using solid wood doors as cabinets? Some of the new doors have great finishes with some kind of inner filler?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...