Go Back   Home > Forums > > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Planet 10 hifi Home of the Frugal-phile™ - Planet 10 HiFi

Reply
 
Thread Tools Search this Thread
Old 26th May 2017, 04:51 PM   #1
silverhairbp is offline silverhairbp  United States
diyAudio Member
 
Join Date: Feb 2011
Default Acoustic control material

I hope Dave let's me post this. It may be helpful. It may also actually belong in a different forum, but I would like to share with my longer-term friends here first.

To put the discussion in context.....

I have been building a particular pair of speakers for (coming up on) 2 years, delayed for medical reasons. It could be considered a FAST system using a Satori MW16P-4 (original design was for an Alpair 10P, but wanted to try the very extended range Satori) with bass help from Peerless 10" 830668 and 12" 830660 plus a little HF help from a SEAS H1189 27TDFC tweeter. All sealed cabinets, first order crossovers, three separate cabinets (bass, mid and tweeter shell) to help in adjusting timing. So, it might be a FAST system or maybe....

OK, that's the speaker system....

I originally used recycled denim, UltraTouch in a thicker version and polyfill as box stuffing for acoustic control. The results were [pause] disappointing. I removed the polyfill and added more UltraTouch with even worse results. Replaced the UltraTouch with polyfill resulting in equally bad results.

Measurements confirmed the boomy problems. Unfortunately, the microphone failed in the middle of testing. Everything I did AFTER the mic failed is PURELY SUBJECTIVE.

I don't know much about the Satori driver, this is my first rodeo with that driver, that line. But I have significant experience with the Peerless 830668 and 830669 drivers in sealed enclosures. This is NOT the way they are supposed to sound. But those earlier designed cabinets were stuffed with wool, as in sheep's fur with just a little UltraTouch.

I went to the local fabric store, purchased a small amount of 100% wool quilt batting to experiment. I started with a mix of wool and polyfill in the upper bass driver (operating alone). The difference was significant, but incomplete. I removed all the polyfill and used all the wool batting in the upper bass sub-enclosure. The result was a drastic reduction in boominess, "ringing" and "cabinet resonance." I repeated the test using a mix of UltraTouch and wool batting. It was MUCH worse than when the wool was mixed with the polyfill.

I ordered a LOT of the same kind of 100% wool batting (Pellon Nature's Touch Wool Batting) from eBay enough for 3 queen sized and 2 king size beds. I am pulling out ALL the previous stuffing and replacing it with this kind of wool material with REALLY good results.

My conclusions from this truly subjective experiment is that, at least for sealed cabinets, polyfill and UltraTouch are ineffective and may have negative results. Wool, though a bit more expensive, is very effective in controlling unwanted activity behind the drivers.

These are my subjective results, subjective observations and subjective opinions in this system in my room. I'm not saying that polyfill or UltraTouch in NOT effective, it just didn't work for me in these specific circumstances. Therefore, please don't start beating me up or calling me names my father didn't think of because your results have been different. Or questioning my sanity (few have ever doubted the question of my sanity - my audio habit / obsession proves it).

The testing is NOT over. I intend to build some acoustic panels to help with room problems. I will try using panels of UltraTouch, multiple layers of wool batting to build thickness to around 1.5" / 35mm, and 1/2" 15mm wool carpet padding. The room needs help beyond a bunch of big artificial plants scattered about.

These experiments won't happen until later in the year since I want to get the crossovers finely tweaked in and also give my eye some time to recover from all the surgeries over the last year (multiple torn and detached retina problems due to old age).

If anyone is interested, I will post pictures of the speakers.

Bill
  Reply With Quote
Old 28th May 2017, 08:36 PM   #2
TerryO is offline TerryO  United States
diyAudio Member
 
TerryO's Avatar
 
Join Date: Nov 2002
Location: Seattle,Wash.
Quote:
Originally Posted by silverhairbp View Post
I hope Dave let's me post this. It may be helpful. It may also actually belong in a different forum, but I would like to share with my longer-term friends here first.

To put the discussion in context.....

I have been building a particular pair of speakers for (coming up on) 2 years, delayed for medical reasons. It could be considered a FAST system using a Satori MW16P-4 (original design was for an Alpair 10P, but wanted to try the very extended range Satori) with bass help from Peerless 10" 830668 and 12" 830660 plus a little HF help from a SEAS H1189 27TDFC tweeter. All sealed cabinets, first order crossovers, three separate cabinets (bass, mid and tweeter shell) to help in adjusting timing. So, it might be a FAST system or maybe....

OK, that's the speaker system....

I originally used recycled denim, UltraTouch in a thicker version and polyfill as box stuffing for acoustic control. The results were [pause] disappointing. I removed the polyfill and added more UltraTouch with even worse results. Replaced the UltraTouch with polyfill resulting in equally bad results.

Measurements confirmed the boomy problems. Unfortunately, the microphone failed in the middle of testing. Everything I did AFTER the mic failed is PURELY SUBJECTIVE.

I don't know much about the Satori driver, this is my first rodeo with that driver, that line. But I have significant experience with the Peerless 830668 and 830669 drivers in sealed enclosures. This is NOT the way they are supposed to sound. But those earlier designed cabinets were stuffed with wool, as in sheep's fur with just a little UltraTouch.

I went to the local fabric store, purchased a small amount of 100% wool quilt batting to experiment. I started with a mix of wool and polyfill in the upper bass driver (operating alone). The difference was significant, but incomplete. I removed all the polyfill and used all the wool batting in the upper bass sub-enclosure. The result was a drastic reduction in boominess, "ringing" and "cabinet resonance." I repeated the test using a mix of UltraTouch and wool batting. It was MUCH worse than when the wool was mixed with the polyfill.

I ordered a LOT of the same kind of 100% wool batting (Pellon Nature's Touch Wool Batting) from eBay enough for 3 queen sized and 2 king size beds. I am pulling out ALL the previous stuffing and replacing it with this kind of wool material with REALLY good results.

My conclusions from this truly subjective experiment is that, at least for sealed cabinets, polyfill and UltraTouch are ineffective and may have negative results. Wool, though a bit more expensive, is very effective in controlling unwanted activity behind the drivers.

These are my subjective results, subjective observations and subjective opinions in this system in my room. I'm not saying that polyfill or UltraTouch in NOT effective, it just didn't work for me in these specific circumstances. Therefore, please don't start beating me up or calling me names my father didn't think of because your results have been different. Or questioning my sanity (few have ever doubted the question of my sanity - my audio habit / obsession proves it).

The testing is NOT over. I intend to build some acoustic panels to help with room problems. I will try using panels of UltraTouch, multiple layers of wool batting to build thickness to around 1.5" / 35mm, and 1/2" 15mm wool carpet padding. The room needs help beyond a bunch of big artificial plants scattered about.

These experiments won't happen until later in the year since I want to get the crossovers finely tweaked in and also give my eye some time to recover from all the surgeries over the last year (multiple torn and detached retina problems due to old age).

If anyone is interested, I will post pictures of the speakers.

Bill
Dear Mr. Bill (Silverhair),

I for one, would certainly be interested in seeing pictures of your new speaker project. In fact, pictures of anything else you'd like to share....for anyone reading this, Bill and I were buddies on the old Bass List. In Audio years, that is about the time that the last Ice Age ended.



Best Regards,
Terry
__________________
"If you have to ask why, then you're probably on the right track."
quote from Terry Olson's DIYaudio Forum application

Last edited by TerryO; 28th May 2017 at 08:55 PM. Reason: Needed it
  Reply With Quote
Old 28th May 2017, 09:23 PM   #3
silverhairbp is offline silverhairbp  United States
diyAudio Member
 
Join Date: Feb 2011
Hey T.O.!! Hope all is well with you and your family. Still want to get up there to scare some fishies.

Let's see if I can figure out all this internet stuff....

So there's a front view, side view, close-up front and side view of the left speaker.

All cherry veneer over 3/4" baltic birch except for the cherry-stained bb front tweeter baffle face and the solid cherry midrange baffle face. Crossover parts all over the place. Time alignment and timing completely adjustable. Cone spike on back of tweeter box to help aim the tw at the listening position.

Doesn't sound too bad for a small system.
Attached Images
File Type: jpg image1.jpg (340.8 KB, 141 views)
File Type: jpg image2.jpg (360.0 KB, 140 views)
File Type: jpg image3.jpg (392.8 KB, 141 views)
File Type: jpg image4.jpg (341.5 KB, 142 views)
  Reply With Quote
Old 28th May 2017, 10:28 PM   #4
TerryO is offline TerryO  United States
diyAudio Member
 
TerryO's Avatar
 
Join Date: Nov 2002
Location: Seattle,Wash.
Hi Bill,

The pictures of your speakers are quite nice and I suspect that sound quite nice as well. I just played my new OB speakers of the first time at the Sound DIY Club meeting last week. They sounded quite neutral and with the 18 inch woofers in H-frames, they seemed to have enough bass. I still have work to do on them before the various Audio get-togethers this summer.

Best Regards,
Terry
__________________
"If you have to ask why, then you're probably on the right track."
quote from Terry Olson's DIYaudio Forum application
  Reply With Quote
Old 3rd June 2017, 04:14 PM   #5
zman01 is offline zman01  Bangladesh
diyAudio Member
 
Join Date: Feb 2011
Location: Dhaka
Acoustic control material
Bill,

Thank you for posting this - interesting findings.

Would you be able to share a pic or two of the insides on how you have lined/stuffed the cabinets with the wool batting?

Can you measure the impedance curve of the drivers fitted in the cabinets?

And wish you a smooth recovery from your surgeries.

Last edited by zman01; 3rd June 2017 at 04:25 PM.
  Reply With Quote
Old 3rd June 2017, 06:52 PM   #6
silverhairbp is offline silverhairbp  United States
diyAudio Member
 
Join Date: Feb 2011
Quote:
Originally Posted by zman01 View Post
Bill,

Thank you for posting this - interesting findings.

Would you be able to share a pic or two on the insides on how you have lined/stuffed the cabinets with the wool batting?

Can you measure the impedance curve of the drivers fitted in the cabinets?

And wish you a smooth recovery from your surgeries.
zman,

The cabinets are not actually "lined" as much as they are 100% stuffed, sealed cabinets. Stuffing the enclosures was made a bit more difficult because I use large right-angle and I-beam cross braces made of 3/4" baltic birch plywood. The stuffing is in those boxes pretty tight and snug against the back of the drivers.

I don't have any facility to measure impedance. Since I'm using medium-large solid state amps (Herron Audio M-1), impedance doesn't matter too much as long as I can work out the crossover (mostly by ear).

BTW, all my electronics (except CD transport) are from Herron Audio. I just haven't heard anything better and question whether I've heard anything as good, regardless of price or other considerations. Just an editorial comment from a biased customer. But I have no financial interest in Herron Audio.

Bill
  Reply With Quote
Old 3rd June 2017, 07:05 PM   #7
zman01 is offline zman01  Bangladesh
diyAudio Member
 
Join Date: Feb 2011
Location: Dhaka
Acoustic control material
Hi Bill,

Thank you for the quick revert.

I cannot find any pics of unpacked Pellon wool batting. Images that I found are all of the retail plastic bag. There are some pics of rolls, but those are of poly-blended or poly material.

I am attaching a picture on some Monacor MDM-3 (from Troel Gravesen's site)- is the Pellon product similar once you unpack it? What is the approximate thickness?

- Zia
Attached Images
File Type: jpg sp38_cab_const_MDM3-2.jpg (33.3 KB, 108 views)

Last edited by zman01; 3rd June 2017 at 07:07 PM.
  Reply With Quote
Old 4th June 2017, 03:42 PM   #8
silverhairbp is offline silverhairbp  United States
diyAudio Member
 
Join Date: Feb 2011
NO POLY BLEND. Use pure wool batting. It comes in a large sheet of material about 3/8" / 1cm thick. Wad it up and stuff it into the enclosure (for sealed) or fold it to create a sheet of desired thickness for lining a vented enclosure.

Here's a link on ebay:

Pellon King-size Natures Touch 120 x 120-inch Wool Batting | eBay

or do a product search on ebay.
  Reply With Quote
Old 5th June 2017, 11:26 PM   #9
TerryO is offline TerryO  United States
diyAudio Member
 
TerryO's Avatar
 
Join Date: Nov 2002
Location: Seattle,Wash.
Bill and all:

The old way to test for the correct amount of stuffing is to place the stuffing in box, then button it up and test with a "clicker"... A "clicker" is just a Triple A battery with two wires and a pushbutton switch in line. Hook it to the speaker box and press and release the button. If the fill is correct it will give a nice "Click", too little fill will give you a Boing! sound and too much will be a indistinct ck sound. Play around with this tester until you can readily recognize the sounds that the differing amount of stuffing will make. OK, you probably already understand that you hook the clicker to the driver, not the Crossover and each driver is tested individually.

This is an old standby trick that Greg (the Altec Man) uses often.

Best Regards,
TerryO
__________________
"If you have to ask why, then you're probably on the right track."
quote from Terry Olson's DIYaudio Forum application
  Reply With Quote
Old 2nd July 2017, 04:49 PM   #10
silverhairbp is offline silverhairbp  United States
diyAudio Member
 
Join Date: Feb 2011
TO -

You're right. Getting the dynamics and timing just right is very tunable. And musical timing, even at the most subtle level, is critical to the musicality of a system. That's why single full-range driver systems work so well. It takes a lot of effort to get the timing just right in a multi-driver system, even a fast system where the "full-range" driver does the heavy lifting. Single driver systems work right "out of the box" for obvious reasons.

I have most of the crossover warts worked out. It's not perfect, but very close. Timing was a critical part of crossover development. Not just "time alignment" of the drivers, by actual leading edge of the dynamics. And this time it only took 26 documented crossover changes (a lot were undocumented because it was immediately obvious they didn't work).

Now it's time to add some controls to overcome problems from a rotten room.

Last edited by silverhairbp; 2nd July 2017 at 04:51 PM. Reason: Edited for clarity of thought - often lacking in senior citizen speaker designer wannabe's.
  Reply With Quote

Reply


Acoustic control materialHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
The damping of the BK-12M inner walls with a thin acoustic material Fortaz Full Range 15 12th May 2014 04:14 AM
Most ultimate 2-way Loudspeaker in low material thickness ? - Kiso Acoustic "HB-1" tiefbassuebertr Multi-Way 8 4th June 2013 04:06 AM
Black acoustic damping material (ala Acousta-Stuf) gvr Parts 2 11th January 2013 12:38 AM
Transformer potting material? what material? rvrazvan Tubes / Valves 38 10th October 2011 05:02 PM
Acoustic centres vs diaphragm material David Gatti Multi-Way 9 10th May 2007 09:55 PM


New To Site? Need Help?

All times are GMT. The time now is 02:56 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki