Tweaks for Sierras & Frankenstein room treatment Qs!

So I was wondering, could the Sierra 1 with NrT tweeter benefit from using a felt tweak such as this?

http://www.stereomojo.com/Diffractio...p_image002.jpg

I remember reading that there was some effect from the diffraction in the measurements that went away when sitting farther or bit off angle (don't remember the details...), but, could the felt still improve anything?

Secondly, we've probably all heard the benefits of room treatment and putting diffracting/absorbing materials on the 1st reflection points. What if you put a panel, right next to the speaker, to cut off directly all of the sound to the right and left of the speaker? And to the other extreme, maybe even another pair of panels on the inside, so that you basically if the speakers are '.', you get some sort of directivity control cone going going panels: \./ \./ That way, you'd pretty much do away with the side wall reflection points... And ifyou could go crazy, do the same for top and bottom reflection points... :eek: Sensitivity would suffer in room (would sound less loud), but would that result in an improvement of sound or not? I've heard speakers sound rather bad in an anechoic room... Would this sound better or worst?

The tweaks are strong in this forum. :D

I'm probably going to test one of the above in the next few days. So that said, I've begun writing the review using comments from a well established & highly regarded tweak, which really make a difference, all I have to do next is to fill the _______ with my tweak, and I'm all setup.

Quote:

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Performance

On first hearing the difference I was really surprised: the _________ brought about a clearly noticeable improvement over my homemade versions. Track after track, it was a delight to confirm that my system was sounding better. I noted hearing greater levels of dynamics, quicker transients and better attack, a darker background and increased musical articulation allowing for a more expressive performance. Also: greater control at frequency extremes enabling music to project more convincingly, all translating into a more believable and musical experience. Switching to __________ was followed by a loss of musical involvement. The sound became emotionally flatter and slower, there was less of that "get up and go" and the corresponding musical energy I so preferred. I quickly went back to the _____________ and continued to listen, long into the night.

I cannot claim to understand fully how ________ work, from a scientific point of view, but I can claim that they do work. Some tweaks in my system are quite subtle in their effect; the ___________ on the other hand are among the select few that clearly demonstrate sonic improvement.

Conclusion

The ____________ are a delightful sonic surprise, hardly because __________ is new to me. I have been doing just that for a number of years with homemade versions and with good results. What surprised me the most, however, was how much better ___________ are from what I have been using so far. They are very well built, easy to use and sonically represent an unmistakable Best Buy.

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;)

Anyway, if I can match the performance from the above upgrade I should be in business right? (ripped review)

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Originally Posted by GirgleMirt

So I was wondering, could the Sierra 1 with NrT tweeter benefit from using a felt tweak such as this?

http://www.stereomojo.com/Diffractio...p_image002.jpg

I remember reading that there was some effect from the diffraction in the measurements that went away when sitting farther or bit off angle (don't remember the details...), but, could the felt still improve anything?

Secondly, we've probably all heard the benefits of room treatment and putting diffracting/absorbing materials on the 1st reflection points. What if you put a panel, right next to the speaker, to cut off directly all of the sound to the right and left of the speaker? And to the other extreme, maybe even another pair of panels on the inside, so that you basically if the speakers are '.', you get some sort of directivity control cone going going panels: \./ \./ That way, you'd pretty much do away with the side wall reflection points... And ifyou could go crazy, do the same for top and bottom reflection points... :eek: Sensitivity would suffer in room (would sound less loud), but would that result in an improvement of sound or not? I've heard speakers sound rather bad in an anechoic room... Would this sound better or worst?

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I have spent a lot of time over the years analyzing various foam / felt options around tweeters. Like everything else in audio, there are benefits and drawbacks. If used properly, it can reduce diffraction effects but it will also absorb higher frequencies (limiting extension) and can dramactically limit off-axis dispersion.

A large piece of thick felt around the tweeter as you pictured will absorb far too much of the tweeter's high-frequency output. In my many years at M&K, we found the best compromise was to use small strips of acoustic foam adhered to the front baffle in precise locations. A fond memory of mine when I was designing the crossovers for the original M&K "K" series was spending several weeks determining the ideal placement of foam. I believe I still have some pictures somewhere of the different foam layouts on the speaker’s front baffle. Ultimately, in various time domain and polar response measurements – I found that less foam was more…

During the design phase of the Sierra-1, I tried several foam/felt options around the tweeter in an attempt to reduce on-axis diffraction effects. Ultimately, I did not like its effects on the overall off-axis response and in designing a loudspeaker; I am more concerned with off-axis performance than on-axis performance.

To answer your question, unless the large amount of high-frequency absorption is accounted for in the crossover, placement of a large piece of felt around the tweeter will dramatically hurt performance…

Hope this helps!

Definitely! Very interesting and even reassuring response! :) Sometimes it can be hard for a consumer to try to determine what is beneficial/worthwhile and what is not, cool to hear that these options were all explored during the design! :D