Go Back   Home > Forums > >

Multi-Way Conventional loudspeakers with crossovers

A Monster Construction Methods Shootout Thread
A Monster Construction Methods Shootout Thread
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools
Old 1st December 2020, 01:30 AM   #271
Sin Phi is offline Sin Phi
diyAudio Member
 
Join Date: Nov 2019
I assume it is something like this, https://www.amazon.com/ROSEROSA-Prof.../dp/B07Z32Z8WB

Though what is more typically used in speakers is the same stuff as cars, https://www.amazon.com/Noico-deadeni...dp/B00URUIKAK/

That is the 80mil version, there are thinner butyl layers like 50mil out there as well. I have yet to build a speaker box with the butyl, but cars and right behind my headboard of my bed outside is the water heater box. Really thin galvanized metal that just made an incredible racket in the wind and rain. Use that to fix it up right. Sound is reduced and what is left is lower pitch.
  Reply With Quote
Old 1st December 2020, 03:00 AM   #272
augerpro is offline augerpro  United States
diyAudio Member
 
Join Date: Aug 2006
Seems similar to the Resonix I tested
__________________
~Brandon
Please help my waveguide and box construction research by donating to my gofundme via my website:Soma Sonus
  Reply With Quote
Old 1st December 2020, 06:24 AM   #273
jzagaja is offline jzagaja  Poland
diyAudio Member
 
Join Date: Jun 2004
Location: Szczecin
A Monster Construction Methods Shootout Thread
Alu with butyl is used for damping cars. Good damping is necessary for elastic plywood 5mm.
__________________
email me jzagaja at gmail
  Reply With Quote
Old 10th December 2020, 11:12 AM   #274
Rnp73 is offline Rnp73
diyAudio Member
 
Join Date: Oct 2018
Newb(ish) suggestion...

I've been going off this for designing a new system: https://qualia.webs.com/newdampingfactors.htm

Which, when the info is put in order (and taking out anything over 300hz) looks like this:

material frequency damping factor
tungsten loaded putty 80 0.725
'Permali' 18mm 220 0.688
'Permali' 6mm 250 0.671
'Newplast' 160 0.635
bentonite filled resin 48 0.618
'Panzerholz' 150 0.599
lead filled resin 100 0.592
bentonite powder filled resin 100 0.518
glass 'Butacite' laminate 150 0.391
'Pyrotek' 6mm 100 0.376
recycled rubber crumb 109 0.348
glass 'Sentryglas' laminate 247 0.317
Page Lacquer' acrylic over mdf 100 0.315
Plasticine' 77 0.304
...

Tungsten loaded putty is available at fishing supply places but too expensive for a bulk coverage. Good for small area decoupling though! Similarly, Permali and Panzerholz is very expensive - not to mention tough to source. So I don't think they are worth considering given the parameters of this testing.

However, bentonite filled resin looks very interesting (and goes looooww), resin (isophthalic, in this case) is relatively cheap and the bentonite for the non-powder version is standard cat litter. Also cheap, and available everywhere. If it's possible to pour a reasonable thickness in the gap of the enclosures, or even make a quick box out of it, that'd be fascinating to see the results. I've ordered some resin anyway, so I'll be trying it out soon...

If I can find a cheap source of tungsten powder, I'm tempted to try a resin with that in as well.

Anyone else have experience with these materials?
  Reply With Quote
Old 16th December 2020, 02:33 PM   #275
454Casull is offline 454Casull  Canada
diyAudio Member
 
Join Date: Jan 2004
Location: Toronto, ON, Canada
HiFiCompass talks about a method to reduce the port resonance here:

Puri Bliss - BeWg | HiFiCompass

Do a Ctrl-F for "N.B. Rozen"
  Reply With Quote
Old 16th December 2020, 10:50 PM   #276
hollowboy is offline hollowboy  Australia
diyAudio Member
 
Join Date: Jul 2007
Location: 'straya
Quote:
Originally Posted by Rnp73 View Post
Newb(ish) suggestion...

I've been going off this for designing a new system: https://qualia.webs.com/newdampingfactors.htm
I've seen a similar list, which included more composite materials than this one. My main take away from it was that ANY hybrid material is much much better than the base material. e.g. MDF with a thin laminate was truckloads better than basic MDF.

That is: a cheap complex material can be better than a simple expensive one.

Also note that a complex shape (a box, with holes and bracing) probably has massively different damping compared to a flat test panel. e.g. a bell and a gun will ring very differently, even if they are made of the same metal.

Quote:
Originally Posted by Rnp73 View Post
Tungsten loaded putty is available at fishing supply places but too expensive for a bulk coverage. Good for small area decoupling though! Similarly, Permali and Panzerholz is very expensive - not to mention tough to source. So I don't think they are worth considering given the parameters of this testing.
Also: a 31 litre box using 2 litres of cheaper kitty litter goo will probably work better (and be less wasteful of a valuable material) than a 30 litre box using 1 litre of tungsten goo.

Unless you are after exoticism for its own sake, or in a bling competition with a millionaire, I can't see any situation where the expense would be worth the marginal volume reduction.

Quote:
Originally Posted by Rnp73 View Post
However, bentonite filled resin looks very interesting (and goes looooww)

Anyone else have experience with these materials?
I've tried a basic bentonite loaded mix (kitty litter and gloopy glue mixed in a slurry like concrete) to line a cheap ABS plastic PA speaker. In this application, it didn't make much / any difference when compared to an identical untreated speaker.

...but I'd rather be disappointed by $10 of materials than by $500 of materials

I've also done some building with a ply / bamboo laminate, because

1) bamboo has really good damping properties
2) it looks really good
3) it is good to work with (really hard surface, machines very cleanly).
4) the stuff I like comes as 2400 * 1200 * 5mm sheet. It is a single layer that is designed to be laminated to a base layer
5) that 5mm thickness is very forgiving of sloppy workmanship
6) it isn't crazy expensive like Panzerholz (I got 4 sheets for $500 Australian)

I like the aesthetics so much, I've done non-audio projects the same way (e.g. stripped old furniture and re-skinned with bamboo).

The only downsides are
- its hardness (and silicon content) makes it more work to cut, and it probably dulls tools more quickly
- it doesn't respond to tools exactly how wood does (e.g. you can't plane it with hand tools)
- the splinters are different to most woods (they can be really fine and really strong, so they go in deep and break off).
__________________
This edit signature thingy is seriously hard to find
  Reply With Quote
Old 16th December 2020, 10:58 PM   #277
augerpro is offline augerpro  United States
diyAudio Member
 
Join Date: Aug 2006
Quote:
Originally Posted by 454Casull View Post
HiFiCompass talks about a method to reduce the port resonance here:

Puri Bliss - BeWg | HiFiCompass

Do a Ctrl-F for "N.B. Rozen"
So the last paper I referenced is that Rozen paper, which is the inspiration for the port(s) Harman developed in their paper, which is the basis for my Harman port here. hificompass utilized a rectangle port, and only used Rozen's curve in one dimension. I would like to try in a rectangle port also (but curved in both dimensions) since these ports look ideal for subs, and a rectangle port made with bender board should be easy enough to fabricate.

hificompass doesn't say much about how he tapped the port and dampened the energy, maybe he will chime in.
__________________
~Brandon
Please help my waveguide and box construction research by donating to my gofundme via my website:Soma Sonus
  Reply With Quote
Old 21st January 2021, 10:14 PM   #278
augerpro is offline augerpro  United States
diyAudio Member
 
Join Date: Aug 2006
I hope to have some new testing soon of new ports and CLD cabinet construction. I'll have one port using the Roozen profile mentioned from the paper above. Assuming that does not outperform the Harman inspired port (if it does I'll use the Roozen profile instead) I'll have a new hybrid combining the Harman profile with taps at 1/2 and 1/4 wavelength that will be filled with stuffing and sealed using some plastic strips to absorb the primary port resonances. I dub thee: AugerPort!!

Click the image to open in full size.
__________________
~Brandon
Please help my waveguide and box construction research by donating to my gofundme via my website:Soma Sonus
  Reply With Quote
Old 21st January 2021, 10:22 PM   #279
tmuikku is offline tmuikku  Finland
diyAudio Member
 
Join Date: Sep 2004
Location: Savo, Finland
Send a message via ICQ to tmuikku
Far out! that is a proper way to utilize 3D printing!
  Reply With Quote
Old 22nd January 2021, 02:46 AM   #280
454Casull is offline 454Casull  Canada
diyAudio Member
 
Join Date: Jan 2004
Location: Toronto, ON, Canada
Exciting stuff! If all else fails, you can use it for some directed-air applications, I'm sure...
  Reply With Quote

Reply


A Monster Construction Methods Shootout ThreadHide this!Advertise here!
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
JLH Mosfet Power amplifier construction thread jamesfeline Solid State 56 15th August 2020 09:28 AM
Studio 350 construction thread jamesfeline Solid State 49 30th September 2019 09:19 AM
monster-6-channel-amplifier-build-thread matt09 Solid State 8 12th April 2016 09:44 PM
Krill construction thread - Sidetracked quoydoy The Lounge 43 12th March 2009 07:51 PM
Ultimate NOS DAC Construction Thread iggy80fr Digital Source 1 11th November 2007 04:14 PM


New To Site? Need Help?

All times are GMT. The time now is 02:36 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki