Wool natural felt is the only material that has the characteristic for sound absorbtion. Just don't put it plain attached to the wall but use your fantasy to make some structures that absorb the nastyness of diffraction/etc.
Maybe we're dealing with a language translation issue here, but your statement as it reads in English is incorrect. Yes, wool products are excellent natural absorbers of sound, but not the ONLY materials to do so and do so very well. As mentioned, both fiberglass and recycled cotton products are extremely effective at sound absorption.
Rewind, is the Bonded Logic what you were referring to that contains Boron? If it is, you got docs or links on that? Thanks.
Greg
Center-to-Center distances required to remove/reduce lobing are a challenge with large area speakers. Commercial speakers with the TPL150H typically butt the two mid-tweet speakers together.
I still like the old school Altec/JBL formula of 18" woofer + 10" midbass + TPL150H, or 90x40 SEOS with compression driver. With a room multi-woofer swarm, using 15" woofers becomes more attractive.
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The latest coaxial compression drivers could make large horns reach up to 20Khz. This might keep large horns from going into storage or being used as planters.
Attachments
...And i would like to add that probably the best absorbing material is reticulated foam (as used by geddes). This is the stuf one uses for real anechoic rooms. Is has very nice shaping possibillities, but is rather expensive.
greetings, Kees
That coaxial BMS driver has some horrible reviews by some DIYers.
Center-to-center distances is a problem, but can be solved with a larger room, I suppose. My ribbon tweeter is 60cm high. Midrange horn is almost a meter in diameter. Tweeters are probably best in the middle with bass under and midrange above. How do I solve that? I probably need to pack everything together as tight as possible and forget about keeping them all along a vertical line.
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No, I can't remember the brand now, but it was a company from Finland that produced cellulose isolation material for houses. When I contacted them they admitted to use some pretty strong chemicals as fire retardation. Not sure if it was boron, but not very healthy, me thinks.
Wiki:
"Offgassing
Many cellulose companies use a blend of ammonium sulfate and borate for fire retardation. Although ammonium sulfate is normally odorless, unexplained emission of ammonia and a resulting ammonia smell has been found in some cases."
I forgot about Bonded Logic. Almost bought a roll the other day. Could be worth e-mailing the manufacturer to ask what else you are buying. Perhaps they throw in some borate for free without customers knowing about it. ^^,
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I tried it and mineral wool (mineral fibers, fiberglass?) sounded better to me. Need to try out Bonded Logic.
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I want to raise the question of a back chamber for the 12p80nd or liberty 8. These seem to have it. http://gallery.audioasylum.com/cgi/gi.mpl?u=2348&f=Oldhorns.jpg
Is it worth to consider or should I just find a good volume?
Is it worth to consider or should I just find a good volume?
Hello everyone! If you do not need high efficiency then recommend looking attention on the Woofer Audio technology ( Flexunits 12 B 77 25 10 and Flexunits 12 D 77 25 10 KAP -sandwich). It have a very low frequency and low distortion. But they are not very high efficiency (90-92), and are not cheap.
Besides the TPL 150, what drives are used in that speaker on the picture.?? Any info would be nice, thanks.
Hi Greg! Do you listen ESS AMT? What you think about original Heil? It is the same like other?
check the website of the manufacturer :
max
i like the design a lot. Just don't know why they used a low efficiency mid/bass unit for midrange duty. I'd certainly try a 8 or 10MI100 from Beyma.
Regarding people recommending the Beyma Liberty 8 driver to be used as a bass/mid woofer , this a a response from a member on a Australian hifi forum, when I asked the question:
Beyma Liberty-8 as a midrange driver - I won't recommend using any instrument driver in a serious reproduction system. The metal dustcap is designed to resonate strongly to add 'sparkle' and 'excitement' to guitar sounds. The dustcap produces high frequency noise not related to the spectral or temporal properties of the input signal - it intentionally adds high frequency components to the sound. This is a fantastic thing for a jazz guitar amp such as the Roland Jazz Chorus 50 - fantastic bright and transparent sound. However, this mechanism of colouration is not at all desirable in sound reproduction.
Thoughts? Maybe the Beyma 12P80ND is more suitable?
Beyma Liberty-8 as a midrange driver - I won't recommend using any instrument driver in a serious reproduction system. The metal dustcap is designed to resonate strongly to add 'sparkle' and 'excitement' to guitar sounds. The dustcap produces high frequency noise not related to the spectral or temporal properties of the input signal - it intentionally adds high frequency components to the sound. This is a fantastic thing for a jazz guitar amp such as the Roland Jazz Chorus 50 - fantastic bright and transparent sound. However, this mechanism of colouration is not at all desirable in sound reproduction.
Thoughts? Maybe the Beyma 12P80ND is more suitable?
I have seen comments from different people at this forum, that cone speakers do not have enough dynamics or vividness in the lower mid frequency range, that they sound somehow dull or dark, and therefore do not keep up, and combine well with compression drivers, or ribbons, above. That does not reflect my experience. The 12p80nd has a lot of clarity, dynamics, while very smooth and natural, and combines flawlessly with the TPL. I will have soon a Hiraga Le class A, with 30 watts, and Hiraga Le Tube preamp. That will probably be my final solution for a long time......
Nice stuff Angelo. Look forward to reading about your 'end of the road' solution
So you feel from your experience that there is no/little sound quality/performance benefits using a big mid-low horn solution (compression driver or woofer), compared to something like a 12" direct radiating woofer in a ported box?
For me, when I moved the goto 15" woofer from a 200L ported box to the 50hz azurahorn designed front loaded bass horn, the scale and the sense of 'effortless dynamics' increased quite noticeably.
That is not to say I don't appreciate direct radiating woofers in ported cabs. I loved the sound of the old JBL 4345 studio monitor. Building a pair myself at the moment!
So you feel from your experience that there is no/little sound quality/performance benefits using a big mid-low horn solution (compression driver or woofer), compared to something like a 12" direct radiating woofer in a ported box?
For me, when I moved the goto 15" woofer from a 200L ported box to the 50hz azurahorn designed front loaded bass horn, the scale and the sense of 'effortless dynamics' increased quite noticeably.
That is not to say I don't appreciate direct radiating woofers in ported cabs. I loved the sound of the old JBL 4345 studio monitor. Building a pair myself at the moment!
Nice stuff Angelo. Look forward to reading about your 'end of the road' solution
So you feel from your experience that there is no/little sound quality/performance benefits using a big mid-low horn solution (compression driver or woofer), compared to something like a 12" direct radiating woofer in a ported box?
For me, when I moved the goto 15" woofer from a 200L ported box to the 50hz azurahorn designed front loaded bass horn, the scale and the sense of 'effortless dynamics' increased quite noticeably.
That is not to say I don't appreciate direct radiating woofers in ported cabs. I loved the sound of the old JBL 4345 studio monitor. Building a pair myself at the moment!
Hi Tuyen
i have experimented with a lot of different solutions and configurations for about 6,7 years. If i'd keep experimenting, i would probably just run in circles. I have compared Fane Studio 8M / 38" horn directly with 12p80nd / closed cab ( i closed the port ), and the difference is very noticable and clear. Its not a unrelevant improvement, i really like it much more. Also the wider dispersion: Its not only when i move around, but also on listening position. The indirect sound provides and gives a greater sense of scale, life atmosphere, and soundstage. When i listened full horn systems in big rooms, the experience was many times very impressive, so maibe horns are better suited for big rooms, and direct radiators with wider dispersion for smaller rooms.