tinitus said:
Where i live (up a small mountain (or a big hill depending on your perdspective -- it is a mountain, just most of it is underwater thou), a small, light agil bike is the most practical and the most fun... the best bike i've had was a highly frankensteined 250 cc Yamaha single. Something in the same theme at 400 cc from any of the Japanese vendors would be fine. The Ducati was about a zillion dollars more than i could afford.
dave
marchel said:
If the TS specs are right, in a closed box it will reach its f3 before it reaches xmax frequency. moving mass and Bl product determine sensitvity, not Vas, except for vey low frequency. If used in a closed box config, you will need a sub, or give up spl for extension
You can trade spl for extension by using a linkwitz transform, adding mass, or notching the spider.
Typically, you have very eff 92-96db drivers with 2-3mm xmax or you have large xmax type motors with 80db eff. This driver has 89-90db eff with large xsus and xmax, making it rather unique. In addition, unlike other large xmax drivers, Xsus is still larger than Xmax
For those who think the driver is worth $100, I would love it at that price, somehow, I don't think scanspeak will price it that way.
ShinOBIWAN said:
thats not what i was talking about. i wasn't talking about rewriting the laws of thermodynamics, merely about bringing a new design philosophy to the table.
2-way with 1" tweeter and 6" woofer is probably the most common hi-fi speaker arrangement ... and this is exactly what they produced.
this would be analogous to something like a front-engine, front wheel drive 2.0 liter 4-cylinder car. if you put nitrous on a honda civic it does not turn into a dodge viper. it turns into a fast civic. this is what this illuminator is - a 500 horsepower civic.
what would be examples of a different philosophy ? well how about
BG ribbon
Raven 3.2 MMX
EJ Jordan fullranges
Fostex 31.5" woofer
i mean those drivers make you stop for a second and think - how am i supposed to use them ? but the illuminator does not. as such i think it makes as much sense as a $200,000 honda civic.
chrisb said:
there is only one driver, its not a stereo setup, just a single subwoofer.
the room is my bedroom. its about 11 by 19 feet. its used roughly between 25 and 80hz. the sub is probably used near-midfield as it sits on the side of my desk which is 5 feet wide. it compliments 8" nearfield monitors (mackie HR824, the old model) which are on the desk and have a 80hz built in high-pass.
power comes from a QSC PLX 2402 amplifier. crossover is behringer DCX2496 and additional equalization is performed with behringer DEQ2496.
overall i think the monitors, subwoofer, amp and room are pretty well matched although the monitors cant quite match the output of the sub. the sub came approximately 1 year after the monitors and i knew the monitors would not be able to keep up with it 100% but thats their problem and not a valid reason to skimp on the sub.
the motivation for building the sub was to see how much cleaner a sub could sound relative to a pair of cheap 12" JBL home theater subs i was using prior to it. my friend basically dissed my JBL subwoofers and said that they sounded like sh1t. i then decided to build the most accurate sounding subwoofer possible.
we decided that for ultimate clarity we would need to go sealed and build a box completely free from all resonances. this was not supposed to be an SPL subwoofer but a sound-quality subwoofer. it just so happened that the lowest distortion woofer i could find also happened to have 8000 watt power handling.
mbutzkies said:
because its all about weight.
did you ever pick up a 76 pound driver ?
my LMS arrived in a wooden crate (because you cannot ship a 80 pound driver in a carton box) and the crate + shipping cost me like $100 extra on top of the driver cost.
of course the crate too was not strong enough to support the weight of the sub so by the time it go to the doorman of my building it was already cracked.
i knew there was no way i could pick up this crate and i did not even attempt to take the sub out of it. instead i finished breaking the crate around the subwoofer until the subwoofer was essentially standing on the floor. i then was barely able to carry the subwoofer itself to my appartment.
compared to a 27" sony trinitron TV the LMS is significantly more difficult to carry. compared to a 55kg woman - about the same.
marchel said:
the only problems i can think of with large excursion are doppler distortion and pressure modulation of the tweeter.
there is nothing about laws of physics that says that longer xmax should have any effect on box size or efficiency. the bass/efficiency/volume tradeoff refers to something else, has nothing to do with xmax.
"there is nothing about laws of physics that says that longer xmax should have any effect on box size or efficiency. the bass/efficiency/volume tradeoff refers to something else, has nothing to do with xmax."
If all things the same , The driver with longer xmax will have lower effeciency or sensitivity, It could also be made sensitive by lightening the mms , But it would raise the FS . It could also have both low fs and good sensitivity by making the suspesion more compliant and the mms kept light, but at the expense of requiring a bigger box, these parameters could change alot , if the xmax is also changed in a given driver.
There is no use in having a long xmax ,If the suspension is not compliant with it, So, In able for the long Xmax to be of any use for a given driver The suspension should be redesigned for it, And that requires making it more compliant , otherwise it will loose efficiency or sensetivity.
OTOH, these new SS woofers uses NEO magnet, which are much stronger than ordinary ones, So I have no doubt that they could have sensetivity , low fs and reasonable box requirement. What I'm having doubt about them though, is their suspension, They dont look that much different from ordinary design, and the surround is not fat enough, from the looks of it, to accomodate the rated xmax without stetching too much and still produce clean sound on long excursion, But who knows.
If all things the same , The driver with longer xmax will have lower effeciency or sensitivity, It could also be made sensitive by lightening the mms , But it would raise the FS . It could also have both low fs and good sensitivity by making the suspesion more compliant and the mms kept light, but at the expense of requiring a bigger box, these parameters could change alot , if the xmax is also changed in a given driver.
There is no use in having a long xmax ,If the suspension is not compliant with it, So, In able for the long Xmax to be of any use for a given driver The suspension should be redesigned for it, And that requires making it more compliant , otherwise it will loose efficiency or sensetivity.
OTOH, these new SS woofers uses NEO magnet, which are much stronger than ordinary ones, So I have no doubt that they could have sensetivity , low fs and reasonable box requirement. What I'm having doubt about them though, is their suspension, They dont look that much different from ordinary design, and the surround is not fat enough, from the looks of it, to accomodate the rated xmax without stetching too much and still produce clean sound on long excursion, But who knows.
HI Tinitus
the 5k with a pair scan d2010 is a perfect nice musical combo ,series xo ,I used it in my small room without sub ,quite decent but the bass are not SS..... or in small sealed box +sub ,powerd with Carver Silver Seven .
Recenty I put the new AyaII 1541a by Peja and WoW my 15w8530k00 revelator output a bass out phisical law ,solid, fast and go very down. !
the component is arrived for this evolution:
http://www.troelsgravesen.dk/Ellam-dappo.htm
PS my english is too bad!
the 5k with a pair scan d2010 is a perfect nice musical combo ,series xo ,I used it in my small room without sub ,quite decent but the bass are not SS..... or in small sealed box +sub ,powerd with Carver Silver Seven .
Recenty I put the new AyaII 1541a by Peja and WoW my 15w8530k00 revelator output a bass out phisical law ,solid, fast and go very down. !
the component is arrived for this evolution:
http://www.troelsgravesen.dk/Ellam-dappo.htm
PS my english is too bad!
marchel said:
1 - "if all things the same" the driver should cost 20 bucks
2 - suspension compliance has nothing (as in zero) to do with efficiency
3 - "the surround is not fat enough" - the woofers you're normally used to have surround 5 times fatter than it should be because they're trying to look impressive. in reality it takes a lot less surround than you think to get good excursion. my woofer only has surround about 1" wide and it gets 4" of peak to peak excursion on it. with the right surround geometry this is possible. fat surround is detrimental to speaker performance, its a marketing gimmick.
look at professional woofers, they barely have any surround or spiders and they get 2 inches peak to peak excursion
Of course, is a question of philosophy
To the price of one scan so we can buy two seas ER18RNX that you will have twice the volume and half impedence, not always these compromises are possible.
Or a big multiway but for me the xo is too complicate .
This one I thinks that is a very interesting speaker ,good compromise
http://www.troelsgravesen.dk/AcapellaNEXT.htm
To the price of one scan so we can buy two seas ER18RNX that you will have twice the volume and half impedence, not always these compromises are possible.
Or a big multiway but for me the xo is too complicate .
This one I thinks that is a very interesting speaker ,good compromise
http://www.troelsgravesen.dk/AcapellaNEXT.htm
http://www.zaphaudio.com/lowxmax.html Zaph reflecting on Xmax
Subs excluded, I think driver surround are normally way too big, too stiff and too heavy
Midrange drivers with heavy surround that would suit a woofer better...I simply dont like it and cant grasp why "skilled" designers continue to do that, in the name of Xmax that is really not needed
Best surround fore mids is said to be coated cloth
A nice ingenious driver like FR125 would be a perfect middriver with less Xmax and better sensitivity
Subs excluded, I think driver surround are normally way too big, too stiff and too heavy
Midrange drivers with heavy surround that would suit a woofer better...I simply dont like it and cant grasp why "skilled" designers continue to do that, in the name of Xmax that is really not needed
Best surround fore mids is said to be coated cloth
A nice ingenious driver like FR125 would be a perfect middriver with less Xmax and better sensitivity
vasyachkin said:
I'm not sure why your surprised that Scanspeak hasn't released an oddball driver, they don't cater to that market. If you look at what they've been doing over the past few decades you'll see its a steady evolution of a successful principle. The drivers you've cited have never been something that's interested Scanspeak, so quite why your disappointed that this time they didn't take the opportunity to gift us with an oddball driver I'm not sure. Maybe next time eh?
There was already talk about custom drivers opening up new ways of thinking but you make things as interesting or straight forward as you feel capable and that includes designing with a seemingly conventional driver such as the illuminator. What about a front or rear loaded horn, or a dipole, or a TL of some sort, or aperiodic, or cardioid and if you've just won the lottery a line array. There's a huge amount of choices that would totally spin your basic 2 way idea on its head and create something very different.
vasyachkin said:
That's mighty impressive and I'm sure your postie thought so too but besides the fact that it cost a fortune to ship and weighs the same as a small girl what does weight have to do with sound quality was the question I think.
BTW the LMS - nice sub. Moves plenty of air. Ilkka's sub tests show the 15" version to be competitive with the best home theater subs around at the moment.
ShinOBIWAN said:
nothing !
but it has everything to do with pain in the rear.
his argument was that weight = not a problem. my argument is that weight = bad.
sometimes you just don't have any choice ... but if there were a neodymium version i would have gone for that.
weight is a resource just like money and space. resources should not be squandered, they should be used frugally. underhung motors do not use resources frugally.
i believe that for tweeters underhung is the only way to go. for midranges i would also prefer underhung. but for woofers it is too wasteful and i would rather have my woofer overhung.
as for neodymium, i would prefer it on all my drivers including subwoofer.
marchel said:
I understand what you are saying and I do like compliant spiders. But, you can design very eff sub and use large xmax. You just need a heavy gage voice coil and feed it 1000+Watts. Look at the the high SPL car subs out there, I am not saying you should buy one, or that they are any good, but they are out there.
Large travel (spider) drivers will lose some sensitivity because they generally require a wider gap than stiffer smaller spiders, which will slightly reduce B which will effect eff.
mbutzkies said:
this is true. thats why professional drivers seem not to have any spider or surround but in reality they have just enough. because any "extra" compliance might result in either performance or reliability penalty.
and having too much surround is even worse than having too much spider ...
Who is interested in group buy for custom SS ?
Simple two way ,cost no object, 6.5 illuminator + tw ,custom detail when will out ....
Simple two way ,cost no object, 6.5 illuminator + tw ,custom detail when will out ....
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