My first Open Baffle Speaker

[SimontY]

I don't really know. That graph shows changes that could be audible, but I suspect there's much more to it than simple frequency response. I only did a fairly quick test because I'm still ironing out my basic crossover design. When I've got the 2nd speaker wired as the first I may try the bubble wrap for a longer audition.

I don't want to comment on the sound because at the minute I'm overwhelmed by the other changes I've made over the course of the day (gone from nasal and shut-in to rather excellent!!)

Simon

[SimontY]

FYI a large part of bringing up the body in voices etc on mine came from using a baffle step correction type filter (coil and resistor in parallel in line to mid driver) and from changing the mid to woofer polarity. That was the final piece of the puzzle for my speaker/room/system. I'll know more with fresh ears tomorrow how great it really is... or isn't!

[audiojoy]

The baffle step correction i too have experimented with over quite extensive resistor inductor values. Yes overall perceived tonal warmth increases, by bringing up the lower-mid/upper bass, and restricitng the upper frequencies. With the emphasis on the lower end of the drivers the solidity/body of the images also improve. However, it does not seem to effect the overall emotional content of the music coming through - the most important bit. This needs much finer gradations of tonal/harmonic variation to achieve.

Listen to a great voice with great tecnique. Listen with and without the tweak, just see if you can hear more detailed characterisation to the voice and with that more expression. Achieving this in my opinion is far far more important than simply shifting tonal balance, although i am sure without the latter the tweak would be probably less effective.

Will not be able to further assess the tweak until Saturday will report back then if it is worth remaining excited over it.

[Bigun]

Originally Posted by audiojoy

Tried it with small bubble single layer front of speakers only....emotion from voices and instruments was once more to my hearts delight restored with an obvious increase in harmonic texture.

I love this kind of innovation ! - gotta laugh though, all these years of effort in the industry to 'remove the veil' covering the sound and here you are adding one back in.

I wonder if there is any connection between your experiments and this:

Midwest Audio Fest
"Those that caught my ear did not necessarily win though. For me the most interesting speaker there was a Planarsonics homemade flat panel speaker brought by L.E. Heavener. Their membranes were cardboard!"


Cardboard has a kind of hollow cell structure like bubble wrap.

[Melon Head]

It is good to see the enthusiasm has returned. I am definitely interested in what you have done here.
Keep going.

[audiojoy]

Done a little bit more experimentation.

Having the bubble wrap on the front of the speaker baffle clearly reduced spl and reduced the tweeters output most severely. Yes there was still that improved emotion and tonal warmth to the midrange, but the high output loss was too restrictive for continued listening. I am surprised that such a strongly audible anomaly was not clearly demonstratd by Simon's measurements. The veil was certainly there and this was somewhat contrary to my original findings, where I clearly had not tested a range of CD's and simply got excited by my midrange vocal findings.

Tonight I replaced the bubble wrap and let it cover only the rear of the speakers. Tweeter was once more unrestricted but to my surprise the apparent microdynamics had clearly improved further. I was extremely pleased by the detail and tonal realism that was coming from the speakers. Furthermore soundstaging and clarity had improved. The instruments seemed more locked in their positions and had clearer focus. Certain instruments were producing that startling factor when they suddenly came into a mix with such clairty and presence. Voices now had even great tonal depth with more air and detail also apparent.

I next repeated the experiment using the larger sized bubble wrap and once again there clearly further improved microdynamics and focus with an overall very much more refined soundfield. There was no obvious attenuation of any frequency or veil apparent. This was clearly a big step forward.

I suspect a lot of the imrpovements may be related to the way the soundwaves travel and how they are controlled by the bubble wrap rather than due to some half baked idea regarding resonance within bubbles!! but i leave those theories to those that are in the know.

Have I at long last successfully married open and closed box sounds without affecting that tremendous clarity and mega dynamic range that we so dearly love open baffles for?? I believe I am getting very close.

Will report back after more listening, but this is, for me at least, at long lasting becoming a truely exciting project. I hope more of you can try this very simple experiment and report back.

[SimontY]

This is interesting stuff.

By the way I only had bubble-wrap over the front of the midrange driver when I took that measurement.

[audiojoy]

Thanks Simon for clarifying that.

More extended listening is reminding me of other missing attributes that may or may not be speaker related, but improtantly are disturbing my ultimate enjoyment of the speakers tonight. Musicality, timimg and rhythm, cohesiveness,some airiness and sound stage definition are areas that seem to be lacking. These are all the more apparent now that i have improved the all improtant area of tone. These may never have been present but i am now focussing my attention on them. My ancillaires may be at fault here, or the inductor resistor combination needs to be re tweaked. Too many drivers??

Not sure but for life like presence nothing else I have heard beats what i have at the moment with a much improved tonal and microdynamic range.

I remember my Avantgarde duos having more air and soundstage definition,my quad esl's were extremely cohesive sounding with great airiness and soundstage definition. Most of my boxed speakers had palpable soundstages.