DIY ESL build/suggestions THREAD (all questions concerning build will be in here)

[joetama 5,000+ posts]

HT Guide has one now.....

 

[thadman 10+ year member]

The reason ESLs usually lack output is because they are asked to provide displacement over an extremely wide range...which it cannot support.

Im planning on using a 7' panel by 16 or so inches wide. If I used a stator spacing of .07"(70mil), I wouldnt be able to use the urethane tape. Keeping the 100:1 stator ratio intact, I would have a maximum of 7" so 2 sections. If I had 2 7" sections, I could expect 1/4" of inactive area of each side of the spacer so I lose 1" of effective radiating area. I am down to 13(2.54) by 84(2.54). This is equivalent to 7045cm^2 with 1.778mm of allowed excursion before contacting the diaphragm... I have to decide whether I will couple it to the RS390HF baffle, but either way the ESL will be placed on a 24"+ baffle. I will get a 3dB+ boost around 283hz...so the dipole effect in actuality will be doubling my displacement down low. I will not be limited by displacement down low by a longshot...although I may have issues with the resonance of the diaphragm if I want to cross at 150hz.

 

[thadman 10+ year member]

I need a material that has higher tensile strength (greater surface tension is linear with output) and lower weight than 3.8um mylar...that also has the ability to hold a static charge and has an extremely high resistance.

Any options?

 

[thadman 10+ year member]

Also if im aiming for a 250hz crossover point to prevent comb filtering the drivers need to have a 1/2 wavelength CTC spacing. I am required to use 1/2 wavelength because I will be listening in the nearfield since it is setup as a linesource. You simply double the frequency to get half the original wavelength (500hz) and then divide the frequency by the speed of sound in inches (rounded to 13397). 13397/500=26.794", the centers of each driver can be no more than ~27" apart. The drivers will exhibit no beaming as they will be spaced closer than 1/2 wavelength of the xover frequency.

The RS390HF also have extremely low inductance (1.0mH if I recall) and a crazy resonance peak right around 1600-1800hz (the peak starts to slope slowly form right around 1.2khz and then things start to get nasty around 1.5khz). The third harmonic of this peak (assuming 1600hz) is 533hz and distortion will start to rise >400hz. I will be crossing nearly an octave below this, so non-linear distortion should be no issue.

Also heres a review of the HF series http://www.mfk-projects.com/rs_12_hi-fi.htm

quoted from the review

Anyway, one amazing thing about this woofer is its ability to perform well up to several hundred Hz. This is a little unusual for this kind of heavy high excursion driver. I guess if you are not too critical you could use this driver to 1Khz but personally I wouldn't use any 12" driver that high except in certain pro-audio applications. I would feel very comfortable however using this driver to 300 Hz. In most of the applications I have planned for it I will not use it above about 140 Hz but that is more because this is what the application calls for rather than any concern with using this driver higher in frequency.

 

I think this driver will be a first rate performer in both di-pole applications and box applications. It seems about as good as the XLS in the mid bass region with some frequencies possibly better on the XLS and others better with the RS. Generally the two are close in the mid bass region. The RS is better at very low frequency and will also be better than the XLS at frequencies above 100 Hz. The RS is also the quieter of the two making it a much better choice for any dipole application than the XLS.

 

[1loudsuv 10+ year member]

confusing

 

[joetama 5,000+ posts]

confusing

I here there is a little of that going around these days... //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[joetama 5,000+ posts]

You ever build these?

 

[1loudsuv 10+ year member]

I here there is a little of that going around these days... //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

i know one thing i aint confused about. room treatment! it rocks i just finished listining to a cd after installing in my towers (1" foam) and on my walls and that made hella ofa good difference in sound quality. remember what they say your not hearing your speakers your hearing your room.

sorry to the op for the thread jack but that day i posted "confused" i was spamming. as i know nothing about crossovers.

 

[thylantyr 10+ year member]

I guess he doesn't love this forum no more......... lol

http://www.htguide.com/forum/showthread.php4?t=25746

 

[joetama 5,000+ posts]

Apparently not.... Oh well...