I comissioned a really nice wideband driver made by SEAS.
It has something in common with their standart version but my design is more linear, has less distortion and looks better.
The unique parameters allow a low frequency extention down to 32Hz.
The price to pay is a rather big cabinet with 88 liters of volume.
Over xmass i had now time to listen.
I am very satisfied with the result.
I decided to offer a kit and this thread is about it.
I will publish more info and pictures soon.
It has something in common with their standart version but my design is more linear, has less distortion and looks better.
The unique parameters allow a low frequency extention down to 32Hz.
The price to pay is a rather big cabinet with 88 liters of volume.
Over xmass i had now time to listen.
I am very satisfied with the result.
I decided to offer a kit and this thread is about it.
I will publish more info and pictures soon.
Sounds like fun. I am just getting into wide band drivers. Is your driver a derivative of the Seas Exotic 8 inch? Might it work well as an open baffle?
Thanks again for your interest in the diy crowd.
Mas
Thanks again for your interest in the diy crowd.
Mas
My driver is optimized for a rather big bass relfex cabinet. It can be used in an open baffle but then you need a sub woofer under 120 Hz.
3 cu ft? as big as some subwoofers. But... wideband makes it interesting.
I can see using this in a particular shape cabinet that would yield some benefits in terms of flatness of mid band response that would make the added volume not terribly difficult to live with.
What sort of sensitivity, impedance and diameter is this driver?
_-_-
I can see using this in a particular shape cabinet that would yield some benefits in terms of flatness of mid band response that would make the added volume not terribly difficult to live with.
What sort of sensitivity, impedance and diameter is this driver?
_-_-
The cabinet is rather wide and high but not very deep. That helps with the baffle step. The driver is placed off center for a smoother response. The driver has an 8" basket, 8 Ohm and i dream about 95dB sensitivity. Maybe 93dB sensitivity is more realistic. I have to make a calibrated measurement.
Most of the impedance is over 8 Ohm because the driver has really low mechanical loos so the peaks in the bass from the reflex are of high magnitude. Also there is EQ, mainly to drop the response in the upper midrange. Because this EQ is done in series with the driver the impedance goes uop in that area.
Most of the impedance is over 8 Ohm because the driver has really low mechanical loos so the peaks in the bass from the reflex are of high magnitude. Also there is EQ, mainly to drop the response in the upper midrange. Because this EQ is done in series with the driver the impedance goes uop in that area.
My wideband has this one as basis :
http://www.seas.no/images/stories/prestige/pdfdatasheet/H1597-08_FA22RCZ_Datasheet.pdf
It has two major ploblems :
You see an impedance mismatch between 500Hz and 800Hz.
This is the (in)famous edge resonance where sound from the voicecoil reaches the edge and travels back, partly canceling and partly amplifying the amplitude response over a certain range. This is a typical problem in a driver that has a low damping sorround.
It goes away with a high damping surround but that swallows deatil and micro dynamics.
What also happens is distortion, mostly second that is not so bad ( a sign of chaos ) but i would like to see that reduces because it can reach up to 3%. That does not sound crossly distorted but it swallows and masks some information.
My driver has a hand applied edge coating that improves that situation but keeps the low loss surround.
My driver also differs over 8kHz where it is diffuse field equalized to compensate for the unavoidable beaming in wideband drivers. So there is some more energy on axis to compensate a loss off axis. I think Ted Jordan is doing the same and also the Manger ( more or less ).
The magnet system of my driver has a rubber jacket that makes it more pretty and damps resonances somewhat.
http://www.seas.no/images/stories/prestige/pdfdatasheet/H1597-08_FA22RCZ_Datasheet.pdf
It has two major ploblems :
You see an impedance mismatch between 500Hz and 800Hz.
This is the (in)famous edge resonance where sound from the voicecoil reaches the edge and travels back, partly canceling and partly amplifying the amplitude response over a certain range. This is a typical problem in a driver that has a low damping sorround.
It goes away with a high damping surround but that swallows deatil and micro dynamics.
What also happens is distortion, mostly second that is not so bad ( a sign of chaos ) but i would like to see that reduces because it can reach up to 3%. That does not sound crossly distorted but it swallows and masks some information.
My driver has a hand applied edge coating that improves that situation but keeps the low loss surround.
My driver also differs over 8kHz where it is diffuse field equalized to compensate for the unavoidable beaming in wideband drivers. So there is some more energy on axis to compensate a loss off axis. I think Ted Jordan is doing the same and also the Manger ( more or less ).
The magnet system of my driver has a rubber jacket that makes it more pretty and damps resonances somewhat.
It is not a driver i regularily sell. The pair shown are in a set of recycled KEF Calinda boxes and are now my godson's (10 rears old).
dave
dave
Hope that you have a much healthier year in 2016 Joachim. [Are you now fully recovered?]
This project takes me back to my first stereo...42" reflex cabs with 12" full range Goodman drivers. [1967] It was a system I could still live with!
This project takes me back to my first stereo...42" reflex cabs with 12" full range Goodman drivers. [1967] It was a system I could still live with!
I had an operation on the open heart.
I have a new aorta and a valve that is supposed to last a lifetime.
Arnold Schwarzegger had the same operation and seems to be fine.
Actually i feel much better then say a year before.
I have a new aorta and a valve that is supposed to last a lifetime.
Arnold Schwarzegger had the same operation and seems to be fine.
Actually i feel much better then say a year before.
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