Polymax Absorb XHD 100mm batts

[Xecuter]

MSDS says ultratel is safe. I paid about $170 per bag of boards. Each bag had 3 boards measuring 2.4x1.2 at 50mm thick.

 

My listening room is in my bedroom, so I sleep in here each night. I've just noticed my allergies and breathing have been a lot worse since installing the traps two months ago.

[ShikiS]

In case anyone is looking for some updated pricing in regards to XHD 100mm in black, I was recently quoted around $270/pack (3 sheets per pack) with a minimum order of 3 packs (Sydney). This was the only decent quote I got, every other quote was 2-3 times the price I was expecting. 

[Ugly]

2 hours ago, ShikiS said:

In case anyone is looking for some updated pricing in regards to XHD 100mm in black, I was recently quoted around $270/pack (3 sheets per pack) with a minimum order of 3 packs (Sydney). This was the only decent quote I got, every other quote was 2-3 times the price I was expecting. 

Can I ask where you got that quote? I may be in the market for some more soon

 

[ShikiS]

15 minutes ago, Ugly said:

Can I ask where you got that quote? I may be in the market for some more soon

This was from Network Building Supplies. For whatever reason the prices vary a lot between stores; the craziest quote I got was $800 a pack. 

 

They've also just arrived today.

[Ugly]

Excellent thanks. The fact that they also deliver is a real plus!

[Xecuter]

Are you using these for panels or traps?

 

XHD at 50mm : 0.19 @ 125hz

Ultratel at 50mm : 0.34 @ 125hz

 

as the thickness increases this only becomes a bigger difference. Almost twice as efficient for low frequency 

The difference is much smaller at high frequency is why I ask..

 

 

[ShikiS]

7 minutes ago, Xecuter said:

Are you using these for panels or traps?

In case you were directing that question at me:

 

I wanted to stay away from any glass fibres as I would be sleeping in the same room. These sheets I got will be used in all four corners of my room, 200mm each corner with 500mm airgap

[Xecuter]

Hmm, I don't really want to sell my traps, since I spent around $1000 building 6 of them...

I noticed that perforated foil faced ultratel was 400% more effective than non faced. Maybe I should just seal them with foil on the front. and put the fabric back over...

 

The sides are sealed with thin underfloor foam which doesn't seem to breathe which is good.

[Guest Peter the Greek]

I'm not sure if its in this thread or others, but using this stuff for corner bass traps is a waste of time isn't it? haven't we bashed that to death recently? 

[ShikiS]

1 hour ago, Peter the Greek said:

I'm not sure if its in this thread or others, but using this stuff for corner bass traps is a waste of time isn't it? haven't we bashed that to death recently? 

From the various threads i've gone through, it seems that with a fairly large thickness/airgap it should make a noticeable impact.

[bjc]

I'd try nylon spandex from Spotlight as it's cheap ($6mt) and stretchy plus it's virtually acoustically transparent otherwise any material would do really! Do you have old bed sheets/fitted sheets that you no longer use......either for covering, painting dropsheets or rags while working on the car are there only use in my house. lol

[Guest Peter the Greek]

15 hours ago, ShikiS said:

From the various threads i've gone through, it seems that with a fairly large thickness/airgap it should make a noticeable impact.

my point was more around effectiveness v cost - just get some bags of cheap fluffy insulation and rest them in the corner of the room. Greenstuff polyester for example.

[WasM]

4 hours ago, Peter the Greek said:

my point was more around effectiveness v cost - just get some bags of cheap fluffy insulation and rest them in the corner of the room. Greenstuff polyester for example.

Another suggestion would be to go to a carpet supplier who usually have left over roll off-cuts from different jobs, who may give it to you for a small fee or free. I had left over carpet in my theatre which I rolled up and stacked in a corner. The weight/thickness helped a heap and its polyester (or wool if you get that).

[almikel]

7 hours ago, WasM said:

Another suggestion would be to go to a carpet supplier who usually have left over roll off-cuts from different jobs, who may give it to you for a small fee or free. I had left over carpet in my theatre which I rolled up and stacked in a corner. The weight/thickness helped a heap and its polyester (or wool if you get that).

I'm not sure how well that would work for absorption trapping - a bit unpredictable regarding gas flow resistivity etc.

 

12 hours ago, Peter the Greek said:

my point was more around effectiveness v cost - just get some bags of cheap fluffy insulation and rest them in the corner of the room. Greenstuff polyester for example.

@ShikiS - your plan of 200mm deep and 500mm airgap will have a noticeable impact deployed in the 4 vertical room corners if wide and tall enough.

Mid bass will be cleaned up substantially.

 

How low they absorb depends on size and air gap.

 

600mm wide (straddling) is the absolute minimum width you should consider to get much absorption <200Hz.

1200mm wide (straddling) is better to absorb down to 150Hz or so.

 

Any issues <100Hz, absorption just gets too big - IME EQ works well here.

 

cheers

Mike

[WasM]

16 hours ago, almikel said:

I'm not sure how well that would work for absorption trapping - a bit unpredictable regarding gas flow resistivity etc.

Yes no test data but its a very cheap way to find out if that corner is going to work before spending up big. The carpet roll would have airgaps between the rolled layers so similar in property to broadband absorbers.

[zydeco]

On 22/08/2018 at 12:43 PM, WasM said:

Got hold of local supply Absorb HD 50mm black for $202. Picking up tomorrow morning.

I'm after a bunch of Absorb HD or XHD but not had much luck here in Perth. Who was the supplier?

[zydeco]

On 07/03/2019 at 6:58 AM, Peter the Greek said:

my point was more around effectiveness v cost - just get some bags of cheap fluffy insulation and rest them in the corner of the room. Greenstuff polyester for example.

Any idea as to how the Greenstuff 2.5 compare to the  Martini HD / XHD in terms of suitability for superchunks?

[Guest Peter the Greek]

1 hour ago, zydeco said:

Any idea as to how the Greenstuff 2.5 compare to the  Martini HD / XHD in terms of suitability for superchunks?

Buy a couple of bags, sit them in a corner and measure. They're cheap. If you dont like the results, stick it in your ceiling

[davewantsmoore]

3 hours ago, zydeco said:

Any idea as to how the Greenstuff 2.5 compare to the  Martini HD / XHD in terms of suitability for superchunks?

The problems with the greenstuff and many like it, is the lack of standardised data for it.

 

For a "superchunk" style trap, where it's velocity only, it's just simply the flow resistance which dominates.... and the volume and area of the trap.    My superchunk style traps are made out of Martini HD, only because of a massive pricing error (lol, bunnings) .... and otherwise I would have looked for something much less expensive  (which would have enabled me to build more/bigger traps due to $).

[acg]

12 minutes ago, davewantsmoore said:

The problems with the greenstuff and many like it, is the lack of standardised data for it.

 

I read somewhere that the Greenstuf R2.5 has a GFR of about 7,000, which seems to be just about perfect for a velocity trap like a superchunk.  Cannot remember where I read that, but from memory it was from someone in contact with Autex.  Of course this is the internet and everything you read here is the absolute truth...

[WasM]

3 hours ago, zydeco said:

I'm after a bunch of Absorb HD or XHD but not had much luck here in Perth. Who was the supplier?

http://www.kingsenergy.com.au/Contact_Us

The factory is actually 5 mins from this place. I went to pickup direct.

[almikel]

On 09/03/2019 at 9:13 AM, davewantsmoore said:

The problems with the greenstuff and many like it, is the lack of standardised data for it.

it's fluffy insulation - enough of it will work well - but you know that

 

On 09/03/2019 at 9:27 AM, acg said:

I read somewhere that the Greenstuf R2.5 has a GFR of about 7,000,

You may be correct - but with fluffy I don't think it matters whether it's 4000 or 7000...in the scheme of things it's all about

On 09/03/2019 at 9:13 AM, davewantsmoore said:

the volume and area of the trap.    

@davewantsmoore - I cherry picked your post and left out GFR because IMHO in the lower realms of GFR (ie fluffy insulation), it's only size that matters...get enough fibres in the way and it doesn't matter so much that a particular product's GFR isn't available - ie IMHO one fluffy product will work similarly to any other fluffy product - assuming a decent "volume and area" of a trap...and of course placing it where velocity traps work (where velocity >0)

 

cheers

Mike

[almikel]

On 09/03/2019 at 5:37 AM, zydeco said:

Any idea as to how the Greenstuff 2.5 compare to the  Martini HD / XHD in terms of suitability for superchunks?

Interesting question...

I'd never use expensive XHD on a boundary - I would always gap it (and place it where velocity was as close to maximum as possible = wavelength/4).

 

I'd be happy using fluffy on the boundary as it's cheap, and know it's working anywhere velocity is >0 with an understanding that to work low it needs to be large/deep and way off a boundary (ie fluffy from front edge of trap back to boundary) - the same rule applies - it's most effective where velocity is highest = wavelength/4 .

 

The term "superchunk" typically implies a corner placed absorption trap "straddling" the corner completely filling the triangular gap behind.

 

I can't see any benefit in using expensive products like XHD to fill the triangular gap behind the straddling trap as the velocity is too low...but I'd think about filling it with fluffy, because it's cheap and the velocity >0...

 

If you can afford to lose the space of big superchunks like 1200mm wide straddling corners floor to ceiling - I'd go fluffy - cheapest fluffy you can find.

It will work wonders to clean up down to around 125Hz or so (and make a big difference to the "in room" sound)

 

Absorption runs out of effectiveness at low frequencies, and in my "leaky" room, I've found EQ to be sufficient to manage issues below what my absorption can deal with to achieve good "in room" bass.

 

"Rigid" rooms are much harder to manage low bass - other solutions may be required.

 

cheers

Mike

[zydeco]

23 minutes ago, almikel said:

I'd never use expensive XHD on a boundary - I would always gap it (and place it where velocity was as close to maximum as possible = wavelength/4).

Thanks. I could use an air gap but, if I've got the figures right, then 80Hz would mean 1m which is impractical in our room?

 

23 minutes ago, almikel said:

If you can afford to lose the space of big superchunks like 1200mm wide straddling corners floor to ceiling - I'd go fluffy - cheapest fluffy you can find.

It will work wonders to clean up down to around 125Hz or so (and make a big difference to the "in room" sound)

 

How would Earthwool from Bunnings work as a "fluffy"? 

[jeffpr]

On 10/03/2019 at 10:10 PM, zydeco said:

Thanks. I could use an air gap but, if I've got the figures right, then 80Hz would mean 1m which is impractical in our room?

 

 

How would Earthwool from Bunnings work as a "fluffy"? 

I used earthwool straddling corners but in a wooden frame and cloth covered .big improvement in bass .