cbc news: Jim Holtz "Statements" speaker help...

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New Member

Join Date: May 2011

Location: Montreal, Canada

Posts: 23

Hi,

I've decided to build the Statements but I have two questions

I was told that it was better to use two types of material in the speaker fabrication for reducing inner cabinet resonance (wood resonance) and another for standing waves and I was not too sure what material to use in those speakers and was this combination of materials really necessary... One thing for sure, I want them to sound REALLY good.

1 - What is the best quality/price dampening and standing wave elimination material for the woofer/bass cabinet. Something good. What material to use in the MIDs section?
If the material is expensive but yield excellent results, by all means, please let me know.

2 - What is the recommended internal speaker cables gauge and quality? I was thinking of using DH-LABS 14awg T-100 Silver Hybrid Speaker Cable.

For those who already built the speakers, was there areas within the cabinet that required thicker/thinner material?

Thanks for the help!
Do

Midrange Member

Join Date: Feb 2011

Posts: 496

1. fiberglass insulation, which you can find at any home improvement store

2. solid core twisted 18 gauge, which you can also find at any home improvement store in a brown jacket called thermostat wire. I just cut the jacket and the wire slides right out. You can twist it yourself. Thiel uses the same type of wire for their speakers.

Senior Member

Join Date: Jun 2006

Location: Atlanta, GA, USA, Earth

Posts: 753

For the boxes, use 3/4 inch MDF or 3/4 inch Baltic Birch Plywood, as you wish. Either is fine. Make sure you install the interior braces as designed.

For fillling the inside of the woofer part, I suggest 2 inch wedge foam:
http://www.foambymail.com/Wedge.html

For inside the mid tunnel, use 1 inch thick open cell foam from Walmart.
Line the inside walls of the tunnel. No more, no less.

HTH,

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Seasoned Veteran

Join Date: May 2008

Location: wisconsin

Posts: 1,457

The originals were made with 3/4" MDF, with an added 1/2" layer on the baffle. Jim Holtz says he used wedge foam, but recommended Owens Corning 703 Fiberglass insulation. That's what I would do. I couldn't find the price per foot of that wire. Do you have it? The whole dh-labs site seems a bit expensive to me, but that's a character defect of mine. I would use zip cord or speaker cable.

Be aware that the TB mids are very delicate, don't touch the cones.

Do what Jim says. He posted while I was composing.

Midrange Member

Join Date: Feb 2011

Posts: 496

Here is a video on how Thiel builds their speakers:

http://techtalk.parts-express.com/sh...ighlight=thiel

If twisted 18 gauge solid core copper wire is good enough for them, it should be good enough for any of us. Thicker wire will only cause you to need more solder on your connections and will typically be more expensive.

Also keep in mind that 16 gauge is more than plenty for nearly all external installs, where 14 gauge and 12 gauge are needed only for long lengths of wire.

I will admit with regard to the inner foam, though I recommended fiberglass insulation, I've been building my statement monitors with this stuff since I have 4.5 sheets of it and need to use it up:

http://www.parts-express.com/pe/show...number=260-516

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Location: Tennessee

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Last edited by theLinks; Yesterday at 02:31 PM. Reason: link

New Member

Join Date: May 2011

Location: Montreal, Canada

Posts: 23

The DH-LAB cable is this one

http://www.solen.ca/pub/cms_nf_catal...d=1623&nobut=1

If I use Owens Corning 703, then I just need 3M #77 glue to hold it in place? 2" thick?

When using this green fiber glass, what happens to standing waves? Are they eliminated as well as the egg crate type acoustic foam?

Thanks

Seasoned Veteran

Join Date: May 2008

Location: wisconsin

Posts: 1,457

3M spray adhesive is fine. $3.32Cdn/ft? Too rich for me, but I'm cheap. Oh, and some people shy away from fiberglass insulation in vented speakers because it might blow out of the enclosure.

If I was five minutes from PE I would be in financial trouble.

New Member

Join Date: May 2011

Location: Montreal, Canada

Posts: 23

Also, for the crossover, could I use Solen caps instead? I have the Solen store 5 minutes away from work so I don't have to pay the shipping charges...

Or should I stick with the original parts in the Crossover?

Thanks

Midrange Member

Join Date: Feb 2011

Posts: 496

Quote:

The DH-LAB cable is this one

http://www.solen.ca/pub/cms_nf_catal...d=1623&nobut=1

If I use Owens Corning 703, then I just need 3M #77 glue to hold it in place? 2" thick?

When using this green fiber glass, what happens to standing waves? Are they eliminated as well as the egg crate type acoustic foam?

Thanks

The standing waves are eliminated in both. Testing has shown that the fiberglass is as good or better than any other options available at a reasonable price.

That wiring is overkill. Think about it. The following articles are very highly recommended.

http://www.av-outlet.com/en-us/dept_216.html
http://www.roger-russell.com/wire/wire.htm#wiretable

If you can run the entire speaker for 16+ feet on an 18 gauge cable, why is there a need to run 14 gauge for two feet of cable off of a single driver in that speaker? You're only increasing your cost and the capacitance of the cable, which is not a good thing.

Quote:

3M spray adhesive is fine. $3.32Cdn/ft? Too rich for me, but I'm cheap. Oh, and some people shy away from fiberglass insulation in vented speakers because it might blow out of the enclosure.

If I was five minutes from PE I would be in financial trouble.

I haven't personally heard of it blowing out. The kind I get is not fluffed, but rather comes in a rolled sheet. It stays together pretty well. It can be attached to the walls using contact cement, adhesive spray, or even staples.

Quote:

Also, for the crossover, could I use Solen caps instead? I have the Solen store 5 minutes away from work so I don't have to pay the shipping charges...

Or should I stick with the original parts in the Crossover?

Thanks

Use what was recommended for the crossover. If the designers believed there would be a significant improvement by using a different part, I'm sure they would have reflected that in the BOM.

Seasoned Veteran

Join Date: May 2008

Location: wisconsin

Posts: 1,457

I just thought OP would like to know that the fiberglass has been discussed as a possible problem. Imagine building these and reading on a forum somewhere about fiberglass insulation coming out the port.

If you want trick wire, consider Deans Wet Noodle R/C car wire. 12Ga, 1060 strands of pure copper, less than 1/2 the price of that DH stuff.

Midrange Member

Join Date: Feb 2011

Posts: 496

Quote:

If you want trick wire, consider Deans Wet Noodle R/C car wire. 12Ga, 1060 strands of pure copper, less than 1/2 the price of that DH stuff.

Right, which is why I mentioned the rolls. I know it comes in fill and roll variants at the stores. I have a pretty hard time pulling the rolled sheet stuff apart, as in, it takes effort, it doesn't just blow away. I guess we (myself included) need to be more specific when recommending fiberglass as the fill stuff wouldn't be suitable for ported enclosures.

With regard to 12 gauge wire, I will say this one thing since I've already said enough about the gauge itself, it is a pain to solder because its so thick and you have to get everything pretty hot. I solder my wires directly to the crossover board, and I know my crossover parts got uncomfortably warm when I was soldering the 12 gauge to them on my first project.

Seasoned Veteran

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You're right, 12 Ga is a bit big.

Midrange Member

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Quote:

You're right, 12 Ga is a bit big.

If I really needed 12 gauge and had to run 100ft+ of wire, I'd probably be ordering it from monoprice anyway.

http://www.monoprice.com/products/pr...seq=1&format=2

At $0.27 a foot, its pretty hard to beat.

Seasoned Veteran

Join Date: Mar 2010

Location: North Texas, USA

Posts: 1,130

No matter what wire you use internally in the speaker, the power still runs through those little bitty wires on the crossover components. Seems like folks forget that sometimes.

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Been Around Awhile

Join Date: Mar 2011

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I often wondered why people ran the big expensive wires when in fact it runs through wire that is like 22 gauge or something on the xover board. Good point fastbike.

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New Member

Join Date: Mar 2011

Posts: 32

Quote:

The standing waves are eliminated in both. Testing has shown that the fiberglass is as good or better than any other options available at a reasonable price.

Use what was recommended for the crossover. If the designers believed there would be a significant improvement by using a different part, I'm sure they would have reflected that in the BOM.

Agree about fiberglass, if you are in Canada I think mineral wool is also common at home improvement places, and dirt cheap. A little more fragile, but works very well, just like rigid fiberglass.

Disagree wholeheartedly about the using only what is recommended for the crossover. If Solen is 5 minutes away, go to Solen. Even if the designers recommended certain brands for caps, resistors, or inductors (they didn't), I would still ignore them, and probably not build anything from somebody that crazy anyway. Stick to the same types and specs and you'll be fine.

Midrange Member

Join Date: Feb 2011

Posts: 496

Quote:

Agree about fiberglass, if you are in Canada I think mineral wool is also common at home improvement places, and dirt cheap. A little more fragile, but works very well, just like rigid fiberglass.

I was under the assumption that if you're ordering everything from one place, unless there's a significant price break getting them locally, you should just order everything at once anyway. A set of parts for statement monitors will be quite large and everything will be available all in one place, part numbers included.

Alternately, you need to have the specific values, take the time and spend the $2 in gas to get to the store locally, then take the time to find and buy everything in a separate trip. Sounds like a hassle when you can just enter the copy and paste the part number and add to cart. That is of course, unless you're getting a big price break.

Naturally, as long as the values are the same, you can go with whatever parts your heart desires, but I was under the assumption that he was considering more expensive components and was wondering if it was worth it. I guess I read a bit too far into it.

New Member

Join Date: May 2011

Location: Montreal, Canada

Posts: 23

Quote:

My problem is that ordering from the States I need to pay shipping, brokerage fees and customs... So a 300$ order will come to ~400$ and that's a real bitch to say the least!