515B and 515-8g - magnet design
Hi,
Could somebody help understand /explain if the difference in the magnet structure provides better bass output as stated in the 515-8G literature (by ALTEC). It is also mentioned there, the coil is 'underhung'.
Does that mean the 515b is 'overhung' and the reason, it does mid bass well.
If there's an existing thread, a pointer would be fine. I found this article with input from GM but not specifically on being hung-up...:D.
http://www.hostboard.com/forums/f700...s-vs-515s.html
Regards.
Re: 515B and 515-8g - magnet design
Here's two pics of both magnets. The difference in width and height is clear. Does that make a difference in the performance.
Why is the 8G (short, large) considered as having better bass ?
The Altec lit says this " the low-frequency voice coil remains in the magnetic gap at all times ". What I'd like to understand is why ?
NOTE: Both pics were taken off the internet. If any copyright has been stomped on, apologies in advance. Happy to have it removed and advised on how to go about it.
Re: 515B and 515-8g - magnet design
If you want a simple explanation, there really isn't one.
A lot of relevant information in the following link:
http://www.xlrtechs.com/dbkeele.com/...ce%20Coils.pdf
Re: 515B and 515-8g - magnet design
Cool, thanks for the link. I'd actually posted another message with photos showing the difference between the two but the post is waiting admin approval I think.
So are the magnet geometries between the two 515s any different ?
Re: 515B and 515-8g - magnet design
Greets!
Nearly all H.E. vintage drivers [including the 515B] are under-hung as well as many current ones, i.e. the VC is shorter than the VC gap, hence don't have much linear/max excursion.
WRT wide band-width [BW] drivers, its overall performance is mostly a function of its inductance [Le], effective motor strength [Qts+Rs = Qts'], diaphragm, suspension design and doping.
GM
Re: 515B and 515-8g - magnet design
Guys, I'm unable to respond to the posts, since my replies are waiting for moderator approval.
Re: 515B and 515-8g - magnet design
Phew ! That took four days to appear. Looks like I'm out of 'moderation' as well. Yipeee !
- - - Updated - - -
Thanks bowtie427ss /Greg.
Is there a difference between the 515B and 515-8G that Altec make a deal off in their literature.
Re: 515B and 515-8g - magnet design
You're welcome!
??? Such as? Not sure what you're referring to unless it has to do with the 'G' having a higher Fs, lower Vas like the original 515 field coil and 803 [416's predecessor] to better load their respective horns designed specifically for them as part of a 'full range' [for the times] speaker system instead of having to use [mass quantities of] EQ to make a wider range of driver specs work 'well enough' in a prosound app.
GM
Re: 515B and 515-8g - magnet design
The Altec 8G lit makes a deal of it by saying " the low-frequency voice coil remains in the magnetic gap at all times ". From what you've explained it looks like they were just stating a fact and probably the 515b /416 are the same as the 8G with respect to the VC gap.
Re: 515B and 515-8g - magnet design
Yes, they're all under-hung with ~ 4 mm Xmax.
GM