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Neodymium: Yes or No?

Discussion in 'Amps and Cabs [BG]' started by guyplaysbass, Mar 19, 2004.

  1. This is one for the speaker guys. I'm thinking of doing a project revolving around the Beyma 12LW30 Neodymium driver. Do any of you guys have specific knowledge of it's "real world" performance. Any input would be greatly appreciated.

    Search for it's specs here- http://www.usspeaker.com/homepage.htm
  2. I don't care for this driver for electric bass. The Qts is too high, and the tuning is wrong. It's a PA driver, IMO.

    If you are interested in Neo drivers, download my spread sheet and sort DRIVERS by the "comment" column to see all the Neo I have cataloged.

    I like the Deltalite 10 about the best.
  3. Eric Moesle

    Eric Moesle Supporting Member

    Sep 21, 2001
    Columbus OH
    Curious bgavin, what is your opinions on the sonic differences between the Deltalite and the regular Delta for bass applications - specifically in a 4x10 arrangement, if that makes a difference?

    Just curious about the design differences.
  4. I will admit that physics isn't my forte but looking at the Deltalite 2510 and the Beyma 12LW30 I see the Qts is the same, .29, in both drivers. By staying under .30 I should be good in a ported enclosure, right? (feel free to chastise me if I'm wrong) I suppose I could have mentioned as well that this will be a 3 way design in a ported enclosure. I'm going for a light weight "Hi-Fi" sounding cab. I appreciate your input on this stuff guys as I'm still learning.
  5. Petebass


    Dec 22, 2002
    QLD Australia
    Actually I've had my eye on that Beyma speaker. If you're like me and prefer a punchy sound that cuts through over lots of bottom end, it could suite you well.

    In a standard SBB4 alignment, put it in a 39 litre (1.39cu.ft) cab and tune it at 38Hz. It will be -3dB at 71Hz.

    If you want to try and get a bit more bottom end out of it, make the cab 60 Litres (2.2cu.ft) and tune it at 50Hz. This will yield a -3dB point of 49Hz.

    THe first option yealds a better result in the excursion department.

    Keep me posted. I'm really curioous to see how this works out.
  6. This is not an SBB4 alignment.

    I have the PDF for this driver, and Fs=51 Hz. The driver Qts is 0.43, which makes it a BB4 type, with the corresponding hump at Fb, and quick rolloff below Fb. The Vb for BB4 is 2.85 cubic feet, or 80,6 liter. This is a substantial size cabinet for a 1x12, and hardly a weight saver.

    My JBL E155 runs in a smaller cabinet than this (2.54 cubic feet) and is correctly tuned for SBB4.
    The E155 at 27 pounds does outweight the Beyma somewhat...


    I figure the Beyma cabinet to be 20.75 x 20.75 x 17.5 inches, with 1.50" baffle recess and slot port. Void free ply + driver weight is 45 pounds. Grille and hardware are extra.

    The much heavier Kappa Pro 12 runs a true SBB4 in only 1.05 cubic feet at 37 Hz, but the total weight is the same at 45 pounds. Higher frequency response, same total weight, smaller size... the Kappa Pro 12 is the obvious choice.
  7. Here's the info I have on the driver (taken from usspeaker.com):

    Beyma 12LW30 $319.00

    Nominal Basket Diameter 12" / 300mm
    Impedance 8 ohms
    AES Power Rating 350 Watts
    Program Power 700 Watts *
    Frequency Response 35Hz - 5.0kHz
    Sensitivity (1W/1m) 96dB
    Voice Coil Diameter 3" / 77mm
    Recom. Enclosure Volume .7-2.47 ft3* /* 20-70 Liters
    Voice Coil Length 17 mm
    Air Gap Height 8 mm
    X Damage (peak to peak) 25 mm
    Magnetic Assembly Weight 5.1 lb. / 2.3 kg.

    Thiele-Small Paramaters:
    Resonant Frequency (fs) 38 Hz
    Impedance (Re) 6.1 ohms
    Coil Inductance (Le) 1.4 mH
    Mechanical Q (Qms) 6.6
    Electrical Factor(Qes) .3
    Total Q (Qts) .29
    Comp. Equivelant Vol. (Vas) 3.85 ft3 / 109 Liters
    Voice Coil Overhang (Xmax) 5.0 mm
    Effective Surface Area (Sd) .0540 m2
    Reference Efficiency 2%
    Displacement Volume 268 cm3
    Low Freq. Response: Bass Reflex Cabinet-Vb=50L, Fb=40Hz

    If someone can explain the descrepencies in fs and Qts between this data and Bruces, I would really appreciate it. I've been swapping e-mail with him and it looks as though I might have to scrap this driver all together. He is right on the money with the Kappa Pro 12A though. I can run a much smaller box (apparently tuned lower) and still be in the same weight catagory. It was already one of my top choices but I really would like to save on weight.
  8. There is a huge difference between the 12LW30 and 12LW30/N drivers.

    I went out to the Beyma site and found the "/N" driver is current, and the 12LW30 mentioned at the top of this thread is obsolete. I'm not surprised, considering the big difference in performance.

    The /N driver is very nice indeed as an SBB4 in 1.4 cubic feet at 38 Hz. It rolls off above 3500 Hz, and is quite usable with a tweeter. I ran this size cabinet using 3/4" void-free plywood and came up with a total weight of 34 pounds in a slot-port cabinet sized approx. 21H x 16W x 14D.

    In SBB4, it will handle 204 watts before exceeding Xmax from 43 Hz and higher. This will produce 115.5 SPL while remaining linear. SPL can peak at 118 at 350 watts rated power from 100 Hz and higher.

    This is a real nice driver. Go for it.
  9. Petebass


    Dec 22, 2002
    QLD Australia
    Now that we've sorted that out, I also say go for it .........and let us know how it goes. I want all the gory details.
  10. Beyma is producing a whole lot of Neo drivers now, from 8" to 18" muthas. No wonder they are the JBL of Spain.

    The 10" Neo 10LW30/N is very interesting also. It has a high F3, like a JBL, but is tuned at 38 Hz in only 0.45 cubic feet or 12,7 liters.
  11. Thanks Bruce! That makes sense. I originally went to the Beyma site and looked at the 12LW30/N. When I inquired to Jose Diaz (Beyma US distributor) about availablity he refered me to usspeaker.com for retail purchase prices where I found the 12LW30. After all my searching of drivers I was thinking they were the same driver! I will re-inquire as to the availability of the 12LW30/N through usspeaker.com. 34lbs is much nicer then 45! Sweet... :D
  12. The US Speaker appears be the /N model. I did not do a 1:1 on the specs, just the Qts.

    Remember the enemy of neo magnets is heat. Over heat 'em, and they are dead. If you plan on driving hell out them, a pair is in order. They will produce about 118 SPL at 200 watts, which is the most I would drive one of mine.

    With my subs, I found 116 SPL is not enough for a loud bar environment, and had to add a 2nd cab to my setup. This put me at 119 SPL (on paper) and is sufficient. Build one first, then add a second 1x12 if need it later.

    I can help you with the layout if you need it.
  13. Petebass


    Dec 22, 2002
    QLD Australia
    Guy, what speakers are you using at the moment? I'm trying to get a guage of what frequencies your ears are tuned for. If your profile is current and you're used to hearing an Acme B4 and Fender 4x12's, we could have a little bit of a problem...........

    I've also got a funny feeling you may end up going for a second cab, partly for volume, but partly to achieve a warmer bottom end. I realise that's not what you want to hear given that the whole idea of the project is to have " a light weight "Hi-Fi" sounding cab", and adding cabs snuffs out the portability benefit, but.................

    The alternative to the second cab is to first try re-training your ears for the new sound. In other words, give yourself a chance top get used to the punch and do without the bottoms. A lot of guys, myself included, prefer it punchy, so I may be worried about nothing. I just want to prepare you a little for the difference.
  14. Pete-

    I dig low, small, and flat hence the Acme B-4. This project is really for a friend. I'm looking for the "best compromise" in the "low, loud, or small... pick two." arena. I'm pretty sure I'll sacrifice some efficiency for sound quality and size. I'm not aiming for the all-mighty 30hz either but slightly higher so "sound quality" is even subjective in this particular instance. The idea would be to have a good sounding, full range (3 way "hi-fi" as low as possible), light weight cab that could be used alone for low-med volume situations and in pairs for louder situations.

    I'm currently most worried about the inherent heat problems with neodymium. I might choose to go with standard ferrite drivers due to this concern. A light weight cab that gets fried at a loud gig would make for a pretty expensive paper weight or door stop. I myself dig headroom but use a lot of restraint and caution in its application. I know many people who aren't as adept at exercising such restraint. They post here all the time! Sorry, that was cheap
  15. Petebass


    Dec 22, 2002
    QLD Australia
    As someone who has been using a neo's for over 12 months, I can safely say I've never had any of these sorts of problems. I've also been keeping an eye on neo speakers used in Bass and PA applications and I've found only one brand to be the centre of complaints, an Bass amplification company that starts with A.

    Generally speaking, those who use Neo's fall in love with them pretty quickly. You'll have a tough time convincing me I need to bring my heavy stuff to a gig. You just get to a stage where lugging gear annoys the hell out of you. Almost every gig in OZ has stairs. I also dated a girl for 4 years who owned a decent sized PA system, so I'm done with back-breaking heavy lifting.............I even came very very close to accepting a gig with one of the hokiest bands in Sydney recently, purely because they have roadies to lug everything around for me...........

    The technology is there so you may as well give it a chance. BEsides in this case, the Neo version of this driver is much better than the standard version.
  16. Fear of over heating also depends on what you are playing.

    For example, my daughter's all girl band writes all their own emo/punk. Her bassist is highly articulate, and not the typical thrash style bass. Most bassists of this genre that play on their bills use a P and strum hell out of it. The sound is a non-stop mish-mash of screaming loud merde. Contrast this to a bass line with rests between the notes, and the driver is getting less current (heat).

    IMO, don't shy away from this Neo driver due to over heating possibilities. A 1x12 is not sufficient for a loud band, no matter what kind of magnet it uses. Add more drivers. It is much easier to carry two 1x12 Neo up stairs than it is carrying a 2x12 ferrite up those same stairs. Four trips to the car for four 1x12 is still easier to carry.

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