Speaker Wood

[BradV]

Not really sure I get what your saying. If your saying that a speakers sound quality is determined by how thick the box is then I would have to disagree. It's not that simple.

Have you ever heard Harbeth speakers?

BTW I have found the quality of the drivers to be by far the major contributor to musical enjoyment.

marc mc

I haven't heard of Harbeth.

Saying, as I said before, a monitors quality or its overall sound production is a function of the drivers and the cabinet - never said "just" the enclosure thickness. So yeah it's not that simple.

In my opinion a drivers quality and its parameters is of much less importance than enclosure design. That is obvious really. Eg Compare driver 'A' costing $60 and driver 'B' costing $600 in the same well designed enclosure and the sound will be quite close. Put Driver 'B' in the worst enclosure imaginable and it will still sound like crap.

 

[Plitron]

All of this enclosure and monitor talk has me thinking. I came upon a single studio monitor years ago. I seem to recall that it was a 4 inch driver, with a tweeter or 2, I don't really remember now. But I did open it up and peek inside. 2 Things struck me and have stayed in my memory. The sophisticated crossover, and the thick cabinet with bracing. I found it curious that such a small speaker would need such a thick cabinet with bracing. But it is all starting to make sense now.:thmbsp:

 

[BwanaJim]

Give me a stone dead speaker enclosure, that's the goal I'm aspiring to.

"A free air speaker produces sound not music."

Oh boy now you've stepped in it.........

 

[AlfaNovember]

It can't be that exotic - I already own one.

The next great advancement in speaker wood isn't wood at all. It seems that NASA discovered, quite by accident, that the insulating tiles used on the belly of the space shuttle...

I've got a surplus insulating tile from the Soviet "Buran" space shuttle. It seems to be some sort of ceramic foam, and it makes a high-pitched "tink" sound when you tap it. While it's fun to hold it in your hand while you blast it with a blowtorch, I don't think it is terribly promising as a speaker enclosure material. Think of a brick made of a fine, uniform volcanic pumice, and you're in the right ballpark.

 

[4player]

Real wood all the way i rekon!!!

Hey guys i have to agree that the price of the speaker does not makes it better as such,i have built a pair of speakers using the drivers and crossover out of an old pair of welling surround speakers and added some cheap jaycar 5" paper cone drivers with a 1200 hertz low pass filter on them and there are made out of 15mm rosewood, i love the sound here is some pics

 

[marc mc]

I can see this is pointless but... I started into DIY by simply trying different drivers in speakers I already had. My findings? every single time I put a higher quality driver in they sounded better, not similar! better. If I didn't think I could improve stuff, I never would have continued. I already owned 20 pairs at that point.

Cripes if what you guys are saying is true then ProAc, Spendor, Harbeth, JMlab, Sonus faber etc are the biggest idiot's around. Because many use box designs they have had for decades, but none of them have stopped cone development for a second. Have you guys held a driver from those brands in your hand?

I did not spend $320 for 2 - 6" drivers for my OB's and add 2 tweeters that cost 1 million dollars to develop because they sounded a bit better! They sound far better. I mean why not just match up the paramiters from the NS1000 drivers and throw a pair of cheap drivers in and see what happens?

Not to mention that this guy could have got a pair of $200 Fostex's that would have been very similar right? Not on your life guys!

http://cgi.ebay.ca/CORAL-BETA-8-FUL...66:2|39:1|72:1215|240:1318|301:1|293:1|294:50

I have used my Beta's in 3 different boxes and I have a friend that has them in a box designed for Lowthers (wrong size) And in every case, mind blowing.

But like I said this is pointless.


marc mc

 

[dnewma04]

You make some strange conclusions based on what other people say.

 

[marc mc]

You make some strange conclusions based on what other people say.

Seems to be just on this forum. Where "hit and run" is very common. I'm used to real actual examples from experience, versus vague inexactitudes.

marc mc

 

[dnewma04]

Seems to be just on this forum. Where "hit and run" is very common. I'm used to real actual examples from experience, versus vague inexactitudes.

marc mc

I'm not following you at all. You asked for examples, I provided both finished speakers and also raw components. Where is the vague inexactitude?

 

[RayW]

Care to share a real example?

For existing speakers using "inexpensive drivers", I would include Indignias, MurphyBlaster MB0W1s, RayWs Bob speakers, GR Research N2X, a few of the Fostex based "full range systems", some of the econowaveguide speakers i've heard, Adire Audio HE10.1s, NHT SuperOnes

I'm used to real actual examples from experience, versus vague inexactitudes.

Didn't Dave just give a bunch of real actual examples?

Cripes if what you guys are saying is true then ProAc, Spendor, Harbeth, JMlab, Sonus faber etc are the biggest idiot's around. Because many use box designs they have had for decades, but none of them have stopped cone development for a second.

I don't think anybody said that high quality, expensive drivers weren't "better". You seem to be putting words in others' mouths here. All of those companies make very nice speakers. I don't think anyone is disputing that.

What Dave said was that listening enjoyment is design based. He means that if you take an expensive driver and put it in a crappy enclosure with a crappy crossover, you're probably going to end up with a crappy sounding speaker. However, inexpensive drivers can be used in a properly designed and built enclosure with a properly designed and built crossover and achieve fantastic results.

If you haven't heard the speakers he gave as examples, then maybe you owe it to yourself to give them a listen. You might be surprised.

I did not spend $320 for 2 - 6" drivers for my OB's and add 2 tweeters that cost 1 million dollars to develop because they sounded a bit better! They sound far better.

Throwing around the cost of your speakers isn't going to convince people they sound any better. It's just an indication of how much disposable income you have.

But like I said this is pointless.

Only if you're trying to convince others that your opinion is the only one that counts. If you're convinced that expensive drivers are the only way to get good sound and you can afford them, then bully for you! Others don't share the same view.

Ray

 

[toxcrusadr]

I have some wonderful lumber that I cut myself, including some old growth, very dense white oak, quarter sawn for beauty and stability. I would dearly love to make some speakers out of this stuff, but after reading this thread I'm not at all sure it's a good idea. I could line it with MDF or plywood, but I'm afraid that rigidly attaching a layer of "live" wood that can shrink and swell seasonally to a layer of very stable MDF or plywood is a recipe for cracking of the oak. Not only that but it's air-dried and not kiln dried. Plywood might be better than MDF, I haven't checked the shrink/swell properties but I would think it's more than MDF so it might be able to keep up. This would be a fabulous looking pair of speakers, and by using a liner I feel the resonance problem of solid wood would be mitigated, but I'm worried about the stability factor.

 

[spkrdtr]

A hit with real experience

Well Marc, here's my 'hit' but I won't run.

After visiting here a few times since this thread's inception, I was quite surprised at how large (9 pages of posts) it had grown.

There's been lots of chat about minimizing cabinet resonances. IMHO material selection, cabinet geometry and bracing are critical considerations in addressing this sometimes problematic loudspeaker issue. However, in the overall picture of plitron's pending loudspeaker project, IMO, cabinet resonances should be factored in his design but not become a critical one. Dickason's LCB references articles and studies showing constrained layering techniques as superior. I recommend plitron invest in this book to use as a reference for his build it 'right' project as it goes well beyond his initial project concern regarding this tread's topic. :yes:

Most cabinet induced resonances of concern occur in the 100-1000 hz region. Stiffening and optimized material selection/geometry should be targeted to raise a problematic resonance >>1000 hz wherein it becomes a non-issue due to the corresponding drop in dB of the resonance itself.

Cabinet resonances can be measured using accelerometers and also a simple contact microphonic technique which I use with my ATB PC software (see attached example using a Spica TC-50i loudspeaker). I plan, in the near future, to do additional comparison testing of before and after stiffining of a NLA cabinet front baffle board.

No one (to my knowledge) has shown quantitatively to what extent the level and at what frequency of resonance are most noticeable to our ears and should be addressed. In which case, we mere mortals are conscripted enmasse to continue to minimize them with the tools and materials we have at our disposal. :sigh:

 

[marc mc]

What Dave said was that listening enjoyment is design based. He means that if you take an expensive driver and put it in a crappy enclosure with a crappy crossover, you're probably going to end up with a crappy sounding speaker. However, inexpensive drivers can be used in a properly designed and built enclosure with a properly designed and built crossover and achieve fantastic results.

Who does not know that? And for simplicity let me say that IMO! if you then put better drivers in the better design it will sound far better. Some here don't think it will.

So, live long and prosper.

marc mc

 

[Zilch]

Seems to be just on this forum. Where "hit and run" is very common. I'm used to real actual examples from experience, versus vague inexactitudes.

The forum's heavy hitters are well represented in this thread, and they're holding up in the face of adversity.

I have some wonderful lumber that I cut myself, including some old growth, very dense white oak, quarter sawn for beauty and stability. I would dearly love to make some speakers out of this stuff, but after reading this thread I'm not at all sure it's a good idea. I could line it with MDF or plywood, but I'm afraid that rigidly attaching a layer of "live" wood that can shrink and swell seasonally to a layer of very stable MDF or plywood is a recipe for cracking of the oak.

Do the constrained layer thing with structural adhesive, and design such that the external panels have the requisite degrees of freedom to move.... :yes:

 

[Goodwill_HiFi]

Balance guys, balance. I bet I could design a cabinet that made some great drivers sound awful, and I bet Zilch could design a cabinet that made some really cheap drivers sound great

 

[toxcrusadr]

I'm not sure how the outer layer could move when very securely glued to the next layer which does not move the same way or at all...I assume (perhaps wrongly) that any two layers should be glued together to prevent them banging against each other. More explanation please?

 

[Plitron]

I'm not sure how the outer layer could move when very securely glued to the next layer which does not move the same way or at all...I assume (perhaps wrongly) that any two layers should be glued together to prevent them banging against each other. More explanation please?

I've heard that even a thick steel bridge can flex.

 

[Urizen]

I've heard that even a thick steel bridge can flex.

Really?

http://www.youtube.com/watch?v=3mclp9QmCGs

 

[toxcrusadr]

Was that a Yorx bridge or Soundesign?

 

[RayW]

Who does not know that?

You seem to be the one arguing against it.

And for simplicity let me say that IMO! if you then put better drivers in the better design it will sound far better. Some here don't think it will.

It will depend. Simply taking a more expensive driver and sticking it in a box with an existing crossover that were not designed for that driver might work out. Then again it might sound terrible. If you design a speaker around cost effective drivers and it sounds good that doesn't mean that blindly substituting a more expensive driver will make it sound better. It might. Even a blind squirrel finds an acorn now and then. Now if you want to state that a better driver in a box/XO designed for it will sound better than a budget driver in a box/XO designed for it, you'll probably get almost universal agreement.

For example, take the Indignia. Many people here on AK have heard it and agree that it is a very good speaker, especially for the money. It uses a ~$20, 6 1/2" woofer. If you take that out and replace it with a high Qts woofer, say a Morel MW166, then you're going to lose all the bass. And since the Indignia has a fairly low XO point you're going to lose any midrange gain from the more expensive driver. You will probably gain some efficiency through the passband but all that will do is unbalance the sound to favor the upper bass/lower midrange. IOW, it will sound bad. The Morel costs $111 but in this instance it won't sound better. It doesn't matter how much the replacement woofer costs or how good it sounds in a correctly designed system, simply sticking it in a design it's not suited for will not make the overall speaker "better".

So, live long and prosper.

Nanoo nanoo.

I'm not sure how the outer layer could move when very securely glued to the next layer which does not move the same way or at all...I assume (perhaps wrongly) that any two layers should be glued together to prevent them banging against each other. More explanation please?

Constrained layer damping means putting a semi-viscous layer between them, not rigidly gluing. I've done it with RTV silicone and had it work out ok. The squishy middle layer will work as 2 interfaces to absorb/reflect sound coming out of the box and will exchange vibrational energy to heat for low frequencies where the whole panel is moving. The tough part is you have to join the outer layer so that it can move without leaving obvious gaps in the box.

Really?

http://www.youtube.com/watch?v=3mclp9QmCGs

Love the Tacoma Narrows Bridge. I remember seeing that for the first time in an engineering course back in college.

Ray