15 inch woofers: which have low moving mass?

[elac310]

Hi all,

It seems that the lowest moving mass for a 15 inch (38cm) woofer is about 70 grams or so. I've read here and there that some Altecs (including copies from GPA and Inosic) achieve an Mms of around 50-55 grams (including airload?).

What is the lowest moving mass value you know of, for a 15 inch woofer still manufactured, and which model would that be ?

Thanks for your help.

[tinitus]

This Faital have 85gr mms
http://www.faitalpro.com/products/sc...p?id=101060100

Supravox, 70gr mms
http://www.supravox.fr/anglais/haut_...rs/400_GMF.htm

Ae TD15M, 70gr mms
http://aespeakers.com/shop/catalog/p...products_id=56

You need to consider Fs as well, or you might end up with just a very big mid driver

[AndrewT]

why are you looking for lightweight mms?

50gms is getting down to around the mms of normal 10inch and 12inch drivers.

[elac310]

@Tinitus: thanks for these hints! The Supravox are indeed one of the best options I've found so far due to other excellent parameters (high Qm, low Fs etc.)

@AndrewT: I'd like to do some further experiments with 15'' woofers whose paramaters promise a good, dry bass "slam" even at reasonable sound levels (in a classical enclosure i.e. without using bass horns). In the past, I've been enquiring about the lowest possible Rms (mechanical resistance) value but was not very successful so far (see Low Rms woofers: your experience? ).

[GM]

Altec/GPA 515-8G has a Hornresp calculated Mmd in the ~39-42 g range based on measured specs. I imagine the ultra expensive GOTOs should be even less. The trade-off for such a low Mmd though is it's a mid-bass horn driver, so doesn't make any bass to speak of unless driven with a high output impedance and even then not a lot since it has a relatively high Fs.

GM

[Patrick Bateman]

Originally posted by elac310
@Tinitus: thanks for these hints! The Supravox are indeed one of the best options I've found so far due to other excellent parameters (high Qm, low Fs etc.)

@AndrewT: I'd like to do some further experiments with 15'' woofers whose paramaters promise a good, dry bass "slam" even at reasonable sound levels (in a classical enclosure i.e. without using bass horns). In the past, I've been enquiring about the lowest possible Rms (mechanical resistance) value but was not very successful so far (see Low Rms woofers: your experience? ).

"Dry bass" isn't due to a low mms
"dry bass" is due to wide bandwidth.

Not coincidentally, woofers with a low mms often have wide bandwidth.

If you want to have your cake and eat it too, look for a woofer with low inductance and wide/flat response.

http://www.diymobileaudio.com/forum/...tml#post783148

[Frode]

Maybe the BD15 could be an alternative?

Frode

[Defo]

Originally posted by Frode
Maybe the BD15 could be an alternative?

Frode

Crazy linearity and bandwidth...

[badman]

I seriously question their FR chart. If it's accurate, it's preposterously good.

[GM]

Originally posted by Patrick Bateman


"Dry bass" isn't due to a low mms
"dry bass" is due to wide bandwidth.[/url]

Actually, as presented, it's neither. It's due to how over-damped the alignment is which with a typical sealed or vented alignment equates to a rising response one whether created by either a low Qts driver and/or increasing stuffing density and/or some other form of EQ, i.e. a 'fast' bass alignment.

The more over-damped it is, the 'dryer' it is and why typically highly damped compression horns are played much louder than folks realize since they let distortion set the upper limit. Just look at a typical DIY tapped horn, it has a low BW and needs both a high Mms and inductance for best performance in the (sub) woofer BW, yet as has been proven has a very accurate ('dry') sounding bass.

GM