Anyone tried NoRez dampening sheets?

[Kooshball]

I am nearing the end of my 3-way speaker build and need to select the correct stuffing / dampening materials. The cabinets are well braced keeping at least one dimension of every unbraced section under 6". construction materials are 3/4" curved sides made of hardboard (same construction applies to my subs), 3/4" mdf for the tops, bottom and back and 1.5" mdf for the front baffles.

I was planning on some filer fill from parts express to use as stuffing in all enclosures but I came across a product called NoRez that is a heavier PSA backed dampening sheet laminate to open cell foam. Is a product such as this needed in a well braced cabinet? Would one also then fill the cabinet with fiber after lining the walls? Would the same rules apply to the sub as to the 3-way monitors?

Thx

 

[fpitas]

You'll get a lot of different opinions; here's mine. I like to line the walls with acoustic foam of some sort, then fill with Acousta-Stuf. NoRez seems like it would make an ideal wall lining. I stuff the cabinets, even for ported enclosures, if the woofer is used up into the midrange. Acousta-Stuf has minimal absorption below about 50Hz, but does a good job eliminating any "boxy" sounds in the midrange.

 

[woodsart]

K, in comparison, I personally think and have read and been told norez is the best, however, the price reflects that. Danny at GR Research is one to discuss this with, but be warned, he really likes it. I built a pair of Jeff Bs Tritons and used norez and it was rock solid and the bass was really nice, more, I believe because of norez. And, I use normal, required bracing on all my speakers as suggested. Subs are different as I have never heard norez required for a sub.

There are also some forums that have discussed this at length, but I don't remember where.

 

[AJ34]

Saw this thread:

http://www.diyaudio.com/forums/multi-way/12917-damping-materials-speaker-cabinets.html

I don't know anything about NoRez but in a self built 2-way, I lined cabinet walls with bitumen-backed carpet tiles picked up very cheap from a carpet store. The tiles had a thin felt layer covering the bitumen on the back which I stuck to the inner cabinet walls with rubber-based glue and stapled to secure. Speakers are still going strong some 15 years later.

I used proper acoustic bitumen pads to damp a 3-way speaker cabinet. These were expensive, needed two layers and were self-adhesive. Again, seemed to work well but then I didn't listen to the speakers without this damping so I can't say what audible difference they may have made.

It's not too difficult to experiment with quantities of foam and wadding (consider making one of the cabinet panels removable - at least initially) to get the best balance because the amount required is very difficult to predict. It's a different matter with permanently attached cabinet linings/damping though. I would guess that in a well-braced enclosure, such as yours, panel damping would be unecessary.

 

[fastbike1]

No rez is meant for thin panels such as automotive doors. It's not really going to do anything for a braced wooden cabinet. If you think it helped, it's more likely expectation bias, since one rarely builds a box with and one without to compare.

 

[Kooshball]

Thanks folks. It looks like I can pass on this product for this project and just stuff it with fiber and see what happens....good thing is that I can always add it later if I encounter some strange sounds.

 

[dudaindc]

No rez is meant for thin panels such as automotive doors. It's not really going to do anything for a braced wooden cabinet. If you think it helped, it's more likely expectation bias, since one rarely builds a box with and one without to compare.

You are right on the money!