Hi guys
Im totally new to the Rabbit hole of Audio Appreciation.
I havnt even listened to a high end audio set up before, so i dont know what my listening style is yet.
I am about to put together a pair of GR Research diy "Bravo" speakers.
But i am unsure about what to use with lining the enclosures.
They recommended lining them with a product called "No Rez" which is a specialty product of a type of double density foam.
Unfortunately its far to expensive to import, so it was advised that i go with something like vinyl tiles or butyl rubber dampening mat.
To be clear this is about reducing vibration of the enclosure not about internal resonance/reflects or whatever its called (a complete noob here)
Although, in thinking about it, i would not have thought that the No Rez did anything for resonance of the enclosure because i was under the impression that it required a certain amount of mass/weight added to the walls for that where the No Rez is just foam.
After doing a bunch of reading online, i am trying to decide between two options.
Butyl rubber sound deadener mat or mass loaded vinyl.
And im leaning more to the MLV unless someone has good reasoning otherwise.
One concern i do have about the MLV, is that with its intended application in vehicles it is advised that you use a Decoupling layer with the MLV because it apparently is more effective when appied with some give to it as opposed to laying it straight against a rigid surface like the sheet metal of a car door ect.
So you lay down a thin layer (1/4") of closed cell foam as the decoupling layer and then lay the MLV on top of that. Would that be necessary with lining a speaker enclosure or would that use case benifit more from it being rigid against the walls of the box?
They are a 2 way ported speaker made from 3/4" MDF (well 18mm because im not is the US)
As a side inquiry, if the No Rez in the set up of these speakers isnt for resonance of
the enclosure itself, would i need to stuff them with something to replicate what ever it was ment to do?
Because even though i dont really know anything about the audio world yet, i do know that every component of the original design of these speaker matters.
From the little that i have learnt so far, i know that Danny from GR Research doesnt do anything to his speaker designs that doesnt matter, so changing one little thing will effect the intended sound of these speakers
And because i have no experience in this field, i wont know if i have messed anything up and i want to start off with these speaker just as they are meant to be so i can adjust and upgrade everything else around the speakers as my taste and appreciation grows knowing that the speaker sound just how they are meant to.
And yes i am aware of the irony of that statement in a post about changing the component of the speakers that i want to stay just as they are meant to be.
But when it costs $200 to ship a $50 product from the US to AUS, some compromises have to be made. Hence the search to find a suitable comparative alternative.
Thanks in advance.
Paul M.
Im totally new to the Rabbit hole of Audio Appreciation.
I havnt even listened to a high end audio set up before, so i dont know what my listening style is yet.
I am about to put together a pair of GR Research diy "Bravo" speakers.
But i am unsure about what to use with lining the enclosures.
They recommended lining them with a product called "No Rez" which is a specialty product of a type of double density foam.
Unfortunately its far to expensive to import, so it was advised that i go with something like vinyl tiles or butyl rubber dampening mat.
To be clear this is about reducing vibration of the enclosure not about internal resonance/reflects or whatever its called (a complete noob here)
Although, in thinking about it, i would not have thought that the No Rez did anything for resonance of the enclosure because i was under the impression that it required a certain amount of mass/weight added to the walls for that where the No Rez is just foam.
After doing a bunch of reading online, i am trying to decide between two options.
Butyl rubber sound deadener mat or mass loaded vinyl.
And im leaning more to the MLV unless someone has good reasoning otherwise.
One concern i do have about the MLV, is that with its intended application in vehicles it is advised that you use a Decoupling layer with the MLV because it apparently is more effective when appied with some give to it as opposed to laying it straight against a rigid surface like the sheet metal of a car door ect.
So you lay down a thin layer (1/4") of closed cell foam as the decoupling layer and then lay the MLV on top of that. Would that be necessary with lining a speaker enclosure or would that use case benifit more from it being rigid against the walls of the box?
They are a 2 way ported speaker made from 3/4" MDF (well 18mm because im not is the US)
As a side inquiry, if the No Rez in the set up of these speakers isnt for resonance of
the enclosure itself, would i need to stuff them with something to replicate what ever it was ment to do?
Because even though i dont really know anything about the audio world yet, i do know that every component of the original design of these speaker matters.
From the little that i have learnt so far, i know that Danny from GR Research doesnt do anything to his speaker designs that doesnt matter, so changing one little thing will effect the intended sound of these speakers
And because i have no experience in this field, i wont know if i have messed anything up and i want to start off with these speaker just as they are meant to be so i can adjust and upgrade everything else around the speakers as my taste and appreciation grows knowing that the speaker sound just how they are meant to.
And yes i am aware of the irony of that statement in a post about changing the component of the speakers that i want to stay just as they are meant to be.
But when it costs $200 to ship a $50 product from the US to AUS, some compromises have to be made. Hence the search to find a suitable comparative alternative.
Thanks in advance.
Paul M.
"No Rezz" looks like a thin layer butyl rubber with foam on top. I'd cover the walls in Dynamat or something similar, and put open cell, acoustic foam on top of that.
The No Rez from GR Research is a 2" thick dual density foam that i think they have developed themselves and is only available from them.
The reason i make a point of that, is that the speaker design was most likely tuned for use with that particular product and i dont know what difference it will make to swap it out for something different.
The reason i make a point of that, is that the speaker design was most likely tuned for use with that particular product and i dont know what difference it will make to swap it out for something different.
Well, I see Dynamat is well expensive too 🙄😱
The reason to use such product is to make the enclosure more 'dead', i.e. soundproof. Which should be the task of an enclosure.
Intuitively, one could put such layers on the outside of the box since the aim is to stop soundwaves.
I find lead sheets to do the same
MLV has been shown many times to not be near as effective as aluminum-faced butyl rubber. Use the correct butyl rubber sheets, then apply either melamine foam if you want to stay near GR's design, or 100% wool batting at @ 1.5" nominal thickness if you want something more cost effective. NoRez does not look significantly different than Sonic Barrier.
When you say 100% wool batting, do you mean home insulation for you walls?
If that is what you mean, would a acoustic insulation work
Like this Acoustic Insulation from Earthwool | Sound Insulation | Soundproofing
I happen to have some of this laying around.
If that is what you mean, would a acoustic insulation work
Like this Acoustic Insulation from Earthwool | Sound Insulation | Soundproofing
I happen to have some of this laying around.
Paul,
I gave away alot of that stuff. I do not like it. A way for Danny Ritchie to build up his cash position.
Naural damping products, wool or cotton, complex polystuff (like acoustastuff) and various fiberglass materials are usually the goto.
Most if the energy that cause the box walls to resonate comes from the pysical attachment of the driver to the box and much less to do with what is happening inside the box.
Damping does little to deal with box resonances. Its purpose is to deal with air space reflections and syandig waves.
There are 2 approachse to dealing with box resonance. One is to lower the (potential) box frequency low enuff that they ar eless objectionable. This is the BBC approach. Very useful if the resonances can be pushed lower than the driver’s bandwidth. This is the “BBC” approach, and used with a speaker that produces bass, i have found that they typically have the fay tubby bass i often asscoiate with the new bigger Harbeths, much the same as heard in the 19070s BC1. Typically uses things like bitumen lining on thin plywood walls to push resonances lower in frequency.
The other approach is to push potential reasonces up high in frequency, recognizing that much less sustained energy is available in music at higher frequencies to get those potential resonances going. If a multiway and the potential resonances are outside the drivers bandwidth so much the better. This is particularly true of LF reproduction.
To achieve 2, which i have shown in practise to be very effective, things like noRez tend to push things the wrong way. There are other guidelines, one which is avoiding using MDF (which sucks for speaker boxes IMO), and using generous, well thot out bracing.
Much of the 0.75” mterial in the US is actually 18mm misnamed as many in the US don’t understand the metre.
dave
What makes you say that MDF is not good for speakers?
I thought it was considered the most neutral option being more homogenous than plywood and more cost effective than hardwood
Though i guess baltic birch seems to be filling that roll just as well these day.
What would you recommended insead of MDF?
I thought it was considered the most neutral option being more homogenous than plywood and more cost effective than hardwood
Though i guess baltic birch seems to be filling that roll just as well these day.
What would you recommended insead of MDF?
MDF is not that stiff (Resonances tend to be lower in frequency), tends to absorb energy and slowly disipate it as a low level gruge colouring everything. f.
Its only asset is that it is cheap and usually readily available. It is not stiff and is not that well damped (broad Q resonances that are typically lower in frequency, more easily excited because of that, and are more auditable).
Its significant reputation is down to VERY good marketing departments that have even convinced talented designes, such as Ritche, who think it is a material from god.
Good 15mm plywood will smoke a 0.75” MDF box (assuming the same attention to detail).
In many places in OZ, better than MDF can be difficult to find. Hoop pine or marine grade ply seems to be avalable in some locales. It does seem thou that a better selection of bamboo plywoods is available, The best iof these (stranded/fossilized) are some of the best sheet building materials available for loudspeakers.
dave
Its only asset is that it is cheap and usually readily available. It is not stiff and is not that well damped (broad Q resonances that are typically lower in frequency, more easily excited because of that, and are more auditable).
Its significant reputation is down to VERY good marketing departments that have even convinced talented designes, such as Ritche, who think it is a material from god.
Good 15mm plywood will smoke a 0.75” MDF box (assuming the same attention to detail).
In many places in OZ, better than MDF can be difficult to find. Hoop pine or marine grade ply seems to be avalable in some locales. It does seem thou that a better selection of bamboo plywoods is available, The best iof these (stranded/fossilized) are some of the best sheet building materials available for loudspeakers.
dave
Wool batting for quilts is widely available and reasonably priced. If you are in EU, I got mine from homeofwool.com
Dave> I don't know what to make of that graph. It doesn't align with what I've measured. MDF does move the primary resonances down a bit in frequency, but Q is not much different than plywood when I've measured it. Overall damping is slightly better than plywood, though I wouldn't say enough to really matter. I wonder sometimes if the preference for plywood from those who have compared the two comes down to the resonances in plywood being in a more appealing frequency range? Just as colored as MDF, but by pure happenstance, a coloration we like better. I have a really hard time squaring this opinion with what I've measured. Not saying I doubt you, but I just don't know what to make of it.
If a good ply is better than MDF, would a resin impregnated ply like F17 Formply be better?
I had considered it as an option before now but discounted it as some things i had read online suggested that unless its high quality homogenous ply like baltic birch then ply is not a suitable option
I had considered it as an option before now but discounted it as some things i had read online suggested that unless its high quality homogenous ply like baltic birch then ply is not a suitable option
It is a measure of the energy available to excite the cabinent walls vrs frequency.
It is easy to show this is second order, but there is a convincing argument for forth order.
Consideably different amounts of energy to excite panel resonances at 400 Hz than 700 Hz.
If one can also make it a (potential) resonace high enuff in Q it also becomes much less likely that a continuous stream of energy from the music exists for long enuff to “charge” the resonance and get it moving.
This approach breaks all sorts of classic common “general guidelines”but it has been proven in practice.
Comes from looking at the problem from a different direction.
Have a look at many of the planet10phif or Woden designs for examples of practical execution.
dave
It is easy to show this is second order, but there is a convincing argument for forth order.
Consideably different amounts of energy to excite panel resonances at 400 Hz than 700 Hz.
If one can also make it a (potential) resonace high enuff in Q it also becomes much less likely that a continuous stream of energy from the music exists for long enuff to “charge” the resonance and get it moving.
This approach breaks all sorts of classic common “general guidelines”but it has been proven in practice.
Comes from looking at the problem from a different direction.
Have a look at many of the planet10phif or Woden designs for examples of practical execution.
dave
No. Everything that Danny Ritchie does and recommends does not matter.
There are things that you will never be able hear any difference from using.
The best example is his tube connectors. A complete waste of time and money. There has never been any proof that they make a sonic difference nor is there any theory to support their use in place of conventional type connectors.
On that other website there is a big fan club for his products, but I would be cautious about accepting everything you read there as fact. Unless, of course, you believe in the tooth fairy. Then some of their posting might make sense.
Listen to Planet10 if you want advice from a real expert.
I am about to put together a pair of GR Research diy "Bravo" speakers.
But i am unsure about what to use with lining the enclosures.
Nothing. Not worth it in panels that small. Add some internal bracing.
But i am unsure about what to use with lining the enclosures.
Nothing. Not worth it in panels that small. Add some internal bracing.
WannaPhile,
If you haven't actually ordered the Bravos yet, you might want to consider some other options at the same price level by well-respected speaker designers.
Both Meniscus Audio and Madisound have quite a few kits in that price range.
I chose Jeff Bagby's Piccolos, $319 US, from Meniscus using SB Acoustics drivers and couldn't be more pleased. But there are many other similar options that are excellent.
You might want to do some more shopping before making a final decision.
And again. If you read just the comments on the other website keep in mind that they are all coming from a very loyal fan boy club. When someone extols the supposed superiority of tube connectors I pretty much discount everything else they have to say.
Both Planet10 and Brett are offering solid advice based on scientific principles. Entirely different from the other website, which is mostly uninformed group think.
If you haven't actually ordered the Bravos yet, you might want to consider some other options at the same price level by well-respected speaker designers.
Both Meniscus Audio and Madisound have quite a few kits in that price range.
I chose Jeff Bagby's Piccolos, $319 US, from Meniscus using SB Acoustics drivers and couldn't be more pleased. But there are many other similar options that are excellent.
You might want to do some more shopping before making a final decision.
And again. If you read just the comments on the other website keep in mind that they are all coming from a very loyal fan boy club. When someone extols the supposed superiority of tube connectors I pretty much discount everything else they have to say.
Both Planet10 and Brett are offering solid advice based on scientific principles. Entirely different from the other website, which is mostly uninformed group think.
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Adding something to the inside of the speaker enclosure to reduce resonance is important I agree. Question is whether HOW it's attached is important? I think the more you "integrate" the material or coating to the surface, the better. Stapled rubber or fabric may be less effective than gluing on the whole surface or painting on a coating that sticks well?
The ideal no-resonance enclosure would be a thick-walled heavy clay or cement-like pot, and then whether the speaker transmits resonant energy or not wouldn't matter much (that said, using a dampening surround on the back of the basket lip makes complete sense.
Then the fill is there to attenuate the SPL of the rear sound waves, which also can reduce standing waves and resonance (as resonance is affected by amplitude - i.e. listen to your speakers at low volume and resonance won't be a factor) - as well as sound waves coming back through the driver and phase issues too.
More effective fill is better consistent with not reducing the enclosed air volume (in sealed systems) too much which reduces efficiency.
The ideal no-resonance enclosure would be a thick-walled heavy clay or cement-like pot, and then whether the speaker transmits resonant energy or not wouldn't matter much (that said, using a dampening surround on the back of the basket lip makes complete sense.
Then the fill is there to attenuate the SPL of the rear sound waves, which also can reduce standing waves and resonance (as resonance is affected by amplitude - i.e. listen to your speakers at low volume and resonance won't be a factor) - as well as sound waves coming back through the driver and phase issues too.
More effective fill is better consistent with not reducing the enclosed air volume (in sealed systems) too much which reduces efficiency.