Yeah it does look rather conventional... the TMWW with dual 8-inchers is a very common architecture... But it is common because it works well.
I will push the near-complete cabinet through my router table. See post #26 of this thread:
https://www.diyaudio.com/forums/multi-way/366347-active-satori-textreme-3.html#post6512046
I will push the near-complete cabinet through my router table. See post #26 of this thread:
https://www.diyaudio.com/forums/multi-way/366347-active-satori-textreme-3.html#post6512046
Build plan is pretty similar to mine in progress. 3 Way w/SB Acoustics Ceramics (woofer choice?)
I could share my waveguide STL's with you if you are interested. Would end up being an extra $55 each speaker with MJF nylon printing and hardware.
I could share my waveguide STL's with you if you are interested. Would end up being an extra $55 each speaker with MJF nylon printing and hardware.
Yes I have been following your thread, also vineethkumar01's thread. How do you like working with the shredded denim insulation? Augerpro is a fan of that stuff, and I may use it on this project.
Thanks for the offer on the waveguide. I am doing this project with a flat baffle. I was able to get a good sound power response and good listening window response (by simulation) without the need for a waveguide.
j.
The shredded denim is nice, no worries about handling and its intended use as structural insulation is nice. I used the Frost King 16x48" rolls, they are about $10 each now. Needed 7 for full coverage of my cabinets. Actual thickness ended up a bit proud of 0.5". Glued it on with a thin layer of DAP WeldWood, as recommended by Troels for bitumen pads and felt, a quart has been plenty for both jobs.
I chose it over felt for cost. Over melamine because I just haven't seen it used much and don't know its longevity despite its higher cost to performance ratio.
It does come a bit loose with excessive handling (my own fault for test fitting it a bit too much), so for peace of mind I glued a thin layer of poly batting over the top with vinyl glue.
It does tend to fluctuate in and out of stock, home depot has it now.
It is going to be interesting for me to see the point of comparison of the 8" subs and active vs. the woofers and passive.
I chose it over felt for cost. Over melamine because I just haven't seen it used much and don't know its longevity despite its higher cost to performance ratio.
It does come a bit loose with excessive handling (my own fault for test fitting it a bit too much), so for peace of mind I glued a thin layer of poly batting over the top with vinyl glue.
It does tend to fluctuate in and out of stock, home depot has it now.
It is going to be interesting for me to see the point of comparison of the 8" subs and active vs. the woofers and passive.
Sin Phi will likely respond. Meanwhile, I'll share my experience:
I started working with the blue cotton stuff >10y ago, for acoustic insulation in rooms (not inside walls) and in speaker enclosures. The thicker versions are difficult to cut cleanly, a real challenge. The mfg suggests specific cutting saws or knives & techniques. Over time, they shed progressively more dust. The latter might or might not be a problem inside an enclosure; there's a possibility the finer particles could work inside driver motors -- the magnet slot, the voice coil. The speakers in which I used the blue fill have long been out of my hands, so I can't say whether there's any evidence this has happened, but it's probably a minor concern. I don't think I'd use it inside enclosures any more. I still have a bag of teased long hair lamb's wool, which is great to work with (the natural oil is great for your skin!
) & acoustically excellent, and sources of such are near me. There's lots of sheep & goats raised in my vicinity.
In Australia there is recycled glass “wool”. It’s made from glass bottles. It’s very cheap and widely available. $30 will cover a 5.1 system with large Floor standers, centre, rears and a large 15 inch sub enclosure (or two) because it’s typical use is in home roofing installation;
For keeping hot properties cool and cool properties warm.
I haven’t done testing in an empirical manner; whether it’s better for tweeters pole pieces or midrange enclosures, lining woofer enclosures or stuffing sub enclosures… but it’s very thick and itchy; so it must be doing something.
For keeping hot properties cool and cool properties warm.
I haven’t done testing in an empirical manner; whether it’s better for tweeters pole pieces or midrange enclosures, lining woofer enclosures or stuffing sub enclosures… but it’s very thick and itchy; so it must be doing something.
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The glass wool fibreglass works really well even better with a layer of automotive lining felt, which also helps to keep the fibres in place. The low density lower R value stuff is better for inside cabinets and it's cheaper too.
Link to the test I did with various stuffing schemes
https://www.diyaudio.com/forums/full-range/303417-range-tc9-line-array-cnc-cabinet-20.html#post5053920
Link to the test I did with various stuffing schemes
https://www.diyaudio.com/forums/full-range/303417-range-tc9-line-array-cnc-cabinet-20.html#post5053920
Damping materials have variable effect on different wavelengths which is described by absorption coefficients of the material. Most damping materials have very low attenuation (absorption coefficient) on low frequencies, then there is fast or slow ramp up to high attenuation ( absorption coefficient close to 1, ~20db ) where the attenuation more or less plateau. Attenuation also varies how the material is positioned in relation to rigid objects (enclosure wall) and the thickness, density etc.
Many materials have low absorption up to some few hundred hertz and then full absorption around kilohertz or two. Only few materials, like glass fiber wool, have useful absorption already around 100Hz or below.
Reasoning from the data I think this is useful info in a way that one can try and select material that doesn't attenuate the lows in a reflex enclosure, where you want to boost the lows, while having sufficiently high absorption where the enclosure / driver / port resonances are. Select material that ramps up the absorption coefficients high enough below the frequencies you want to attenuate inside the box, but no lower if you want to take advantage of the back signal (reflex and various transmission lines).
Well, people use what ever they have or others have used and recommend, but I think the absorption coefficients are the key information if one really needs to go deep end with tuning the damping.
Here is nice list to see what some common materials have https://www.acoustic.ua/st/web_absorption_data_eng.pdf
Many materials have low absorption up to some few hundred hertz and then full absorption around kilohertz or two. Only few materials, like glass fiber wool, have useful absorption already around 100Hz or below.
Reasoning from the data I think this is useful info in a way that one can try and select material that doesn't attenuate the lows in a reflex enclosure, where you want to boost the lows, while having sufficiently high absorption where the enclosure / driver / port resonances are. Select material that ramps up the absorption coefficients high enough below the frequencies you want to attenuate inside the box, but no lower if you want to take advantage of the back signal (reflex and various transmission lines).
Well, people use what ever they have or others have used and recommend, but I think the absorption coefficients are the key information if one really needs to go deep end with tuning the damping.
Here is nice list to see what some common materials have https://www.acoustic.ua/st/web_absorption_data_eng.pdf
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The problem with standard absorption coefficients is that they are random incidence made in a reverberation chamber and don't translate very well at specific incidence angles.
From Sound Reproduction Floyd Toole
7.3.1 Absorbers
Absorption, Figure 7.5b, is complicated by the fact that the absorption performance of acoustical materials is not specified for specific angles of incidence. For first reflections that matters. Figure 7.6a shows the random incidence absorption coefficient for 2-inch (50 mm) 6 pcf (100 kg/m3) fiberglass board, as quoted in manufacturer’s literature. It shows that this material has essentially no absorption below about 100 Hz and the numbers imply “perfect” absorption above about 500 Hz. This specification is rigorously standardized and requires measurement in a reverberation chamber, with a highly diffuse—random incidence—sound field. The number is an indication of the relative absorption capabilities of materials, but it is not a percentage. The absorption coefficient often exceeds 1.0, and its measurement is not a precision operation. Its origins lie in the history of controlling reverberation in somewhat diffuse auditoriums for live performances. In the small “dead”spaces used for sound reproduction, from homes to cinemas, there is little diffusion in the sound field.
From Sound Reproduction Floyd Toole
7.3.1 Absorbers
Absorption, Figure 7.5b, is complicated by the fact that the absorption performance of acoustical materials is not specified for specific angles of incidence. For first reflections that matters. Figure 7.6a shows the random incidence absorption coefficient for 2-inch (50 mm) 6 pcf (100 kg/m3) fiberglass board, as quoted in manufacturer’s literature. It shows that this material has essentially no absorption below about 100 Hz and the numbers imply “perfect” absorption above about 500 Hz. This specification is rigorously standardized and requires measurement in a reverberation chamber, with a highly diffuse—random incidence—sound field. The number is an indication of the relative absorption capabilities of materials, but it is not a percentage. The absorption coefficient often exceeds 1.0, and its measurement is not a precision operation. Its origins lie in the history of controlling reverberation in somewhat diffuse auditoriums for live performances. In the small “dead”spaces used for sound reproduction, from homes to cinemas, there is little diffusion in the sound field.
For sure, but if one has to go this level of detail with damping (seeking out absorption coefficients) one is probably prepared to test various materials in the box and how they perform anyway I think the coefficients can help weed out some unsuitable products for given application, or give hint how thick of a layer is needed. Mucho info in few numbers that characterize material in relation to other materials, even if they werent absolute metric.
Rules of thumb for damping seem to have worked perfectly fine for decades and is good way to approach damping. I find the absorption coefficients interesting detail though and it is not mentioned too often in the forum. Might be helpful info on some occasions where last micro meter of performance has to be dug out for what ever reason
I think the coefficients can help weed out some unsuitable products for given application, or give hint how thick of a layer is needed. Mucho info in few numbers that characterize material in relation to other materials, even if they werent absolute metric.Rules of thumb for damping seem to have worked perfectly fine for decades and is good way to approach damping. I find the absorption coefficients interesting detail though and it is not mentioned too often in the forum. Might be helpful info on some occasions where last micro meter of performance has to be dug out for what ever reason
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The Porous Absorber Calculator will give you a much more realistic representation of the thickness and resistivity of material to get the desired effect. There is a multi one too where you can mix and match materials.
Porous Absorber Calculator
Porous Absorber Calculator