Panzerholz

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Bumpy

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Panzerholz
« on: 2 Jul 2021, 09:19 am »
Anyone use, or considered using Panzerholz 'wood' for OB baffles? It seems to have amazing qualities that reduce the transmission of unwanted vibrations.

FullRangeMan

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Re: Panzerholz
« Reply #1 on: 2 Jul 2021, 09:32 am »
I dont know this wood, but In OB vibrations are small there is no box, I could use the cheapest or real wood if funds allow.

Bumpy

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Re: Panzerholz
« Reply #2 on: 2 Jul 2021, 09:56 am »
I dont know this wood, but In OB vibrations are small there is no box, I could use the cheapest or real wood if funds allow.

If I put my ear to the main baffle I can quite easily hear the mid range driver playing its music. My main baffle is 55mm void free birch.

I guess this means the main baffle is vibrating along and will eventually re-emit those vibrations to fog the SQ. It may be less than a box but in the quest for ultimate SQ would contribute. I live by the saying that in sound quality, everything matters.

Equally the 15" bass driver will be transferring its vibrations to the mid range driver.

OB builders have chosen various alternatives to alleviate this effect which include the use of separate 'isolated' baffles for each driver and mounting drivers from their magnets. I was hoping to explore the option of a vibration 'free/adsorbing' baffle.

ThePriest

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Re: Panzerholz
« Reply #3 on: 2 Jul 2021, 11:36 am »
Vibration is definitely a factor in OB, as there is little to no bracing to dampen or break it up.

My approach has been to separate the bass units from the midrange and tweeter. Easily done when using GR research OB bass.
For the midrange/tweeter baffle, a sandwich construction can be a good idea.
My baffle is made of steel, to which a 30 mm baltic birch board has been glued, with a 2 mm layer of non-hardening marine glue.
The midrange drivers are mounted in the birch board, not the steel front baffle.


/The Priest


Bumpy

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Re: Panzerholz
« Reply #4 on: 2 Jul 2021, 12:01 pm »
Vibration is definitely a factor in OB, as there is little to no bracing to dampen or break it up.

My approach has been to separate the bass units from the midrange and tweeter. Easily done when using GR research OB bass.
For the midrange/tweeter baffle, a sandwich construction can be a good idea.
My baffle is made of steel, to which a 30 mm baltic birch board has been glued, with a 2 mm layer of non-hardening marine glue.
The midrange drivers are mounted in the birch board, not the steel front baffle.


/The Priest

Interesting and a good option if you are starting from scratch. For me its about a 12-20mm panel mounted in front of the main baffle as in the picture. I quite like the idea of a sandwich construction, but open to any other ideas.



Peter J

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Re: Panzerholz
« Reply #5 on: 2 Jul 2021, 02:13 pm »
Bear in mind that resonance and vibration are two distinct things. Although intertwined when it comes to loudspeakers, resonance is an aural thing and vibration is a mechanical one. One can certainly cause the other and nothing is immune... all things resonate at some frequency, the key with speakers is to keep it outside audible range.

Vibrational energy cannot be "drained away" as I've seen written way to many times. It can be converted to some other form, heat being the most common, but not the only possibility. I didn't take away a lot from Science class, but do remember that energy is neither created or destroyed.

Box resonance issues are certainly reduced with open baffle, but construction materials can still audibly resonate. Generally speaking, dense and, to some degree, flexible or malleable are good bets to mitigate unwanted resonance. I think we tend to think in terms of "more is better", and particularly in the audiophile arena, more money spent means better result.

I don't know if Panzerholz would make a good open baffle construction material or not, but like many things it's not a  panacea where "one size fits all" nor does it have magical properties that will make our lives better somehow. To me, that's where the theoretical discussions go off the rails.

Norman Tracy

Re: Panzerholz
« Reply #6 on: 2 Jul 2021, 05:39 pm »
Anyone use, or considered using Panzerholz 'wood' for OB baffles? It seems to have amazing qualities that reduce the transmission of unwanted vibrations.

My research returns that while a very advanced material Panzerholz is:
  • Very expensive, circa $1,000 a sheet.
  • Difficult to obtain in North America.

I would love to be proven wrong on the above statements. A similar material combining natural fibers heavily impregnated with resins are the bamboo ply woods.

S Clark

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Re: Panzerholz
« Reply #7 on: 2 Jul 2021, 06:41 pm »
Yep, it's just stupid expensive.  I looked at it for lining an inside closet for a tornado room.  Living in central TX, it's a concern.

WGH

Re: Panzerholz
« Reply #8 on: 2 Jul 2021, 08:39 pm »
I have used Richlite to control speaker cabinet resonances, it works very well. Richlite is similar to Panzerholz, both use a phenolic resin with the Richlite having thinner layers. Richlite is made in Tacoma, WA.

All sizes and thicknesses up to huge is available, as an example a 30" x 60" x 1" thick is $316.95. It also is available in 1/2" - 2" thick sheets. Sample sets are $35.

https://richlite.com/





Depending on your location you may find Richlite at eco-builders or high-end counter top suppliers.

FullRangeMan

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Re: Panzerholz
« Reply #9 on: 2 Jul 2021, 09:44 pm »
If I put my ear to the main baffle I can quite easily hear the mid range driver playing its music. My main baffle is 55mm void free birch.

I guess this means the main baffle is vibrating along and will eventually re-emit those vibrations to fog the SQ. It may be less than a box but in the quest for ultimate SQ would contribute. I live by the saying that in sound quality, everything matters.

Equally the 15" bass driver will be transferring its vibrations to the mid range driver.

OB builders have chosen various alternatives to alleviate this effect which include the use of separate 'isolated' baffles for each driver and mounting drivers from their magnets. I was hoping to explore the option of a vibration 'free/adsorbing' baffle.
This a prob, do you had used rubber rings tô install the drivers ?
It cán be used felt rings also.

Audiosaurusrex

Re: Panzerholz
« Reply #10 on: 3 Jul 2021, 01:19 am »
Anyone use, or considered using Panzerholz 'wood' for OB baffles? It seems to have amazing qualities that reduce the transmission of unwanted vibrations.
So I use a Panzerholz record weight on my Acoustic Signature Triple X with amazing results. I would imagine very pricey but would be fantastic for baffles. I think my Spatial M3’ Sapphire baffles are quite nice though  :icon_lol:





Bumpy

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Re: Panzerholz
« Reply #11 on: 3 Jul 2021, 07:34 am »
I have used Richlite to control speaker cabinet resonances, it works very well. Richlite is similar to Panzerholz, both use a phenolic resin with the Richlite having thinner layers. Richlite is made in Tacoma, WA.

All sizes and thicknesses up to huge is available, as an example a 30" x 60" x 1" thick is $316.95. It also is available in 1/2" - 2" thick sheets. Sample sets are $35.

https://richlite.com/





Depending on your location you may find Richlite at eco-builders or high-end counter top suppliers.

I am very much liking the qualities and price of this. Can you tell me how it machines and cuts. Many of these exotic materials rapidly dull power tools such as routers.

Bumpy

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Re: Panzerholz
« Reply #12 on: 3 Jul 2021, 07:35 am »
Bear in mind that resonance and vibration are two distinct things. Although intertwined when it comes to loudspeakers, resonance is an aural thing and vibration is a mechanical one. One can certainly cause the other and nothing is immune... all things resonate at some frequency, the key with speakers is to keep it outside audible range.

Vibrational energy cannot be "drained away" as I've seen written way to many times. It can be converted to some other form, heat being the most common, but not the only possibility. I didn't take away a lot from Science class, but do remember that energy is neither created or destroyed.

Box resonance issues are certainly reduced with open baffle, but construction materials can still audibly resonate. Generally speaking, dense and, to some degree, flexible or malleable are good bets to mitigate unwanted resonance. I think we tend to think in terms of "more is better", and particularly in the audiophile arena, more money spent means better result.

I don't know if Panzerholz would make a good open baffle construction material or not, but like many things it's not a  panacea where "one size fits all" nor does it have magical properties that will make our lives better somehow. To me, that's where the theoretical discussions go off the rails.

Good info. Thanks

Bumpy

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Re: Panzerholz
« Reply #13 on: 3 Jul 2021, 07:41 am »
This a prob, do you had used rubber rings tô install the drivers ?
It cán be used felt rings also.

I use options of cork, felt and rubber rings on the drivers. On these vintage drivers they were often built in at time of manufacture. Here is the Altec 416 15" driver with cork gasket.


Peter J

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Re: Panzerholz
« Reply #14 on: 3 Jul 2021, 02:23 pm »
I am very much liking the qualities and price of this. Can you tell me how it machines and cuts. Many of these exotic materials rapidly dull power tools such as routers.

Richlite is hard...really hard. It will dull HSS quickly, carbide somewhat less fast. Just like anything else hard, cutting will reduce tool edge life...no free lunch. I have a 1" piece here I experimented with and it was surprisingly difficult to get through saw. Perhaps different tool geometry would work better, but I doubt it will ever cut "like butta".

I imagine Panzerholz would be similar.

Bumpy

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Re: Panzerholz
« Reply #15 on: 3 Jul 2021, 02:28 pm »
Richlite is hard...really hard. It will dull HSS quickly, carbide somewhat less fast. Just like anything else hard, cutting will reduce tool edge life...no free lunch. I have a 1" piece here I experimented with and it was surprisingly difficult to get through saw. Perhaps different tool geometry would work better, but I doubt it will ever cut "like butta".

I imagine Panzerholz would be similar.

Thanks Peter. As you say, no such thing as a free lunch :(

Bumpy

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Re: Panzerholz
« Reply #16 on: 3 Jul 2021, 02:42 pm »
My mind is now turning to using the existing 12mm birch ply circular baffle, but mounting it on say a 5-10mm sound absorbent sheet.

This will combine the merits of a sandwich construction and a sound absorbent material such as closed cell 'rubber'.
Its a technique which used a lot on automobiles to remove unwanted noise.

Any suggestions for the composition of the full gasket.

Something like this might do

https://www.ebay.co.uk/itm/313528181899?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D233037%26meid%3D841fc602803f44c0a0dd4a56bd544185%26pid%3D101195%26rk%3D11%26rkt%3D12%26sd%3D203228759170%26itm%3D313528181899%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv9PairwiseUnbiasedWeb%26brand%3DUnbranded&_trksid=p2047675.c101195.m1851&amdata=cksum%3A313528181899841fc602803f44c0a0dd4a56bd544185%7Cenc%3AAQAGAAACIIkUQSKFxxlvm2%252B26VKdW27%252F9KnuFQl%252BwzyhKOSgHNW8uuASdADKeLNApWg2X7ecvXDR2I985lx6Zw2ZFgL6rIGfmtpP5sYsUjmW4ixpdtqXUOBiGYo7xpqdFi2h4koCHRnfcsyguxrKsXfIG0QqOxyvIFthChhT3wN%252BGyVr%252F0SkV%252FCzku%252BmjkivH1XCadpDONACELJKuY1I9hfWmWgJy%252FwsXWlyWz0yD4aWhO7ixJQ3YzhkONXp%252Ft1NQpVb4WPn08UdE1JJSlZvmly9L1t7DEzb9vSHb5JRi21JHQc81juAET5s0VhC0fqLV2lLxtu7g16T2v9a3gbyV3yUvRtV87l6x1PTJ4bljJji82rC4ttUQ7n2QDTrXHkqfJFb1Tbq9kUfaSOEV4UpQM6hue9VzG2ekJc8mWbZIETPAwLgW5ocbYrdfnyp3%252F1rMWLJ4Xsad4gvKBY40EHyzVoQ6iP1xUZjWBdezoUKsfCh2SSk6rz%252Boc%252FroVMUgTUAEDUIVUDXEB%252Be8BE12k954AY6%252BHIsprm6H%252FpK%252FoLMfQlp%252FGZapSeoo33oRLKdqfhCGTAETn8dczqfUMcqjKwewEbIyP1Km3gB0jfuhBLKlNDhEhohuXS4XkpipLv1bbxSIxlkbAodS9yOWucAZ7qn4D%252FmKqK%252FVKoJcw2FxZ%252F9beFRsUA4cVgcLU96KYBOfjuajSvxuSW6g1Z6edXT%252FNuM%252FhobCMmebSw%253D%7Campid%3APL_CLK%7Cclp%3A2047675

FullRangeMan

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Re: Panzerholz
« Reply #17 on: 3 Jul 2021, 02:43 pm »
I use options of cork, felt and rubber rings on the drivers. On these vintage drivers they were often built in at time of manufacture. Here is the Altec 416 15" driver with cork gasket.
Seems the felt and rubber rings will suffice, the less resonant cabinet I have see today was made by myself baffle is 60mm HDF (30+30mm) the drivers are 10'' 200Wrms pro audio FR drivers, unfortunately the whole enclosure weighed 150kg.

If you are sure you want the no resonance kind of sound I suggest 30mm HDF baffle or 30+30mm for extra visual impact, however it should be noted that Baltic Birch and real wood will offer a performance with more resonance with a very nice sound also, IMO among HDF, BB and RW there is no better it varies according each one personal taste, just avoid thin 20mm slabs it will vibrate with any material.
« Last Edit: 3 Jul 2021, 11:26 pm by FullRangeMan »

WGH

Re: Panzerholz
« Reply #18 on: 3 Jul 2021, 03:57 pm »
I am very much liking the qualities and price of this. Can you tell me how it machines and cuts. Many of these exotic materials rapidly dull power tools such as routers.

Yes, as Peter said is is hard and dense. I used a table saw with a carbide tipped triple chip saw blade (not a flat tooth that is for riping wood), a blade designed for wood (pointy tips) would be destroyed.
Cutting the 1" and 2" thick Richlite requires a steady hand and powerful motor, I used my 12" 5hp 3 phase Powermatic table saw with no problems.
I also have a 10" Delta Unisaw from 1950 with a big 1 hp motor that would have bogged down. A commercial saw with an industrial quality blade is necessary for safety.
A cheap thin blade will heat up, start warping and binding in the cut resulting in the possibility of a kickback.



I get my router bits from Grizzly Tools. The carbide bits are excellent quality at a very fair price. I treat all my router bits as a disposable item, they are a cost added to job, not something precious to be pampered and saved.
The Supercut Carbide-Embedded Bandsaw Blades are the best I have used for hard abrasive woods like mesquite and cheaper than a true carbide tipped blade.

Countertop suppliers/installers will often have sink cutouts and scraps they throw away. They can be a source for material to experiment with before making an investment buying large sheets of Richlite only to find out your tools can't handle it.

FullRangeMan

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Re: Panzerholz
« Reply #19 on: 3 Jul 2021, 05:10 pm »
This Ebay link is really big.