Beyma 12MW/ND the 3012LF/HO in-betweener?

[5StringPocket]

With it's high Xmax, power rating, and extended low end, the Eminence Kappalite 3012LF is the gold standard for 12" woofers (light weight or not). At the other end of the spectrum, the 3012HO uses a similar magnet structure but differences in the voice coil and other components to achieve a more full range response with extraordinary midrange efficiency. The 3012HO also has high displacement-limited power handling with good Xmax and low frequency response but the voicing is quite different from the 3012LF because low frequency extension is traded for improved midrange efficiency and wider range of response.

A cabinet is a sonic recipe with built in design preferences, so I set up these two extremes as a useful comparison reference to ask the question: Is there another driver out there with high Xmax and displacement limited power handling which can split the difference between these by providing better low end extension than the 3012HO and higher midrange sensitivity than the 3012LF?

The Eminence Deltalite II 2512 and most other 12" drivers available to the DIY community occupy this middle ground but all that I've looked at are displacement limited at significantly lower wattage or have anemic response between 50 - 200 Hz. The Beyma 12MW/ND seems to stand out from the pack and hang well with the 3012LF and 3012HO.

Why the curiosity? I'm contemplating a 1212/66 Nidacore build with a pair of Faital W6N8-120 mids and ask this on the basis of my (possibly flawed) perception that a pair of 3012LF's would provide a low end that's deep and wide but not as focused as the traditional 410/212 cabs I'm used to. Also, Roger Baer chose to go with his own OEM driver which is voiced in this direction rather than use the 3012LF in his ML-212 design.

I'm sure a pair of 3012LF tuned to 48Hz would be splendid in this application but want to consider the impact of using a pair of Beyma 12MW/ND tuned to 54Hz. Frequency responses and SPL at 700 watts for two 3012LF/12MWND/3012HO are included along with a picture of the proposed cab. The amps I'd use would be the Genz Benz Shuttle 12.0 Max or Streamliner 900. Even with an amp rated at 900 watts, not all power goes to the woofers. Based on what I've read I'll assume about 80% power to the woofers and 20% to the mids (hence the 700 watt figure). Comments based on experience with 1212/6 or 1212/66 cabs or advice to keep the assumptions realistic are welcome. Sorry for the poor WinISD plot image quality. The leftmost curve is the 3012LF, with the 3012HO on the right and 12MWND in the middle.

Driver Xmax Displacement Sensitivity MaxPower Fbox Vbox
3012LF 9.1mm 496cc 95.5dB 450wrms 48Hz 4.30ft3
12MW/ND 7.5mm 412cc 97.0dB 350wrms 54Hz 3.90ft3
3012HO 6.6mm 330cc 100.5dB 400wrms 60Hz 3.40ft3

Frequency Response

SPL at 700 watts rms

[OldogNewTrick]

I am by no means an expert... but to me the Beyma 12MW/Nd models really nicely.


at Fb fo 54Hz, the driver benefits IMO from a slightly larger Vb. Instead of 55ltrs as you suggested, I'd go to 60 or even 65ltrs at the same tuning and include a LR4 highpass at 35Hz pre power amp.

What's more, the speaker is pretty reasonably priced at EUR 185 vs 169 for both Kappalite 12's.

So, IMHO, good call

[rpsands]

Post maximum SPL charts.

I think you'll find some things you don't like with that 54hz tuning -- really too high for a box that big.

3012HOs shouldn't be tuned to 60hz either. It may make your transfer function chart look nice but that is only half the story.

If you're going to simulate with 700 watts, look at the cone excursion chart to go along with that -- or did you?

[rpsands]

I went ahead and loaded this driver up and I think it'd be OK with 54hz in that box size with a 4-string bass. 350 watt displacement limited at 40hz (which is fine).

For 5-string, you must use a good quality high pass filter with that high of a tuning. Running a bunch of 30hz through that box with that tuning will be a recipe for blowing drivers left and right (exceeding xmax with 100 watts @ 30hz).

Even with a 4th order butterworth @ 35hz, you only increase your 30hz handling to 350hz, but that should be fine in most cases.

I'd still aim to tune the box to 50hz--gives you a little more margin for error.

[5StringPocket]

Thanks for the replies. My basses are all 5-string but the Genz amps have a nicely placed HPF which protects drivers from unruly ultra low frequencies and keeps the bottom tight. The Uber 212 cab I use with these amps handles the 5-string very nicely with no damage or fartout. I think that Genz uses 300 watt OEM Eminence drivers and would think that the Beyma 12MW/ND could keep up with this.

You may have a point with the tuning for 5-string. Increasing Vb from 3.9 to 4.3 ft3 and lowering Fb from 54 to 50 Hz lowers the frequency at which cone excursion exceeds Xmax from 45.7 to 43.5 Hz. The Genz Benz Uber 212 and 410 cabs which handle my low end just fine have lowest useable (-10dB) frequencies of 42 and 45 Hz but I'm sure these aren't at max rated power so I'm trying to get a feel for useful comparisons.

If you unload the drivers all bets are off but it would seem that if you avoid large amounts of sub 45 Hz material with proper use of the bass knob, gain, and your ears this would not be a problem. If the Beyma 12MW/ND would fold in this application it's not a contender but I'm not trying to rattle the rafters or play large outdoor gigs without a FOH system, just looking to hold down a solid rock, blues, or funk groove at moderate to loud stage volume. I'm still open to what I might be overlooking.

One other miscellaneous question: What is the shelf port correction factor for WinISD pro?
Since a shelf port which uses 3-sides of the cab has a longer effective length in the same manner that a Klipsch corner horn uses the walls of a room, the estimated port length for a given tuning seems about 25% too long.

[dhomer]

ISD cannot calculate shelf ports. But I did find a neat online calculator AJ Design Software Subwoofer Engineering Math Science Freeware Programs, that will figure that out for ya. Correction factor will be 2.227

[evert_cap]

Hi 5 string pocket, did you finally build it with the Beyma? Any experiences you want to share (I am also looking to buy this Beyma's 12mw/nd for two 50 liter cabs).

[billfitzmaurice]

Originally Posted by 5StringPocket

Since a shelf port which uses 3-sides of the cab has a longer effective length in the same manner that a Klipsch corner horn uses the walls of a room, the estimated port length for a given tuning seems about 25% too long.

That's not actually the case. It's not the position in the cab that makes a difference, it's the width to height ratio of the duct. If that's very high, as in a 24 inch by 1 inch duct, there's more effective length due to the increased friction drag on the air column. With a more typical shape the difference is slight.

As to the 12MW/ND, it's a good driver if paired with a midrange. But like most of Beyma's offerings it doesn't have the rising midrange typical of drivers designed specifically as musical instrument woofers, so it might not meet expectations when used alone.

[ptidwell]

5 string
Don't know if you have started or completed this project, but first I agree with BFM post and would suggest looking at the Faital Pro 6PR150 as opposed to the W6N8-120 and the Faital 12FH500 its 45-4kHz @ 97dB SPL and 7.25 XMAX may be more to your liking than the Beyma 12MW/ND. It has worked for me.
However, with a lower tuning.

Edit: I take back my comment about the 6PR150, since you are not using a horn, the 10kHz top on the W6N8 makes sense. The 6PR150 is 100-5kHz where as the W6N8-120 is 100-10kHz

[5StringPocket]

Pat, if I remember right, you've used both the Faital 12FH500 and the Eminence 3012LF in your 12" cabs. My only experience with a 12FH500 was in a Dr. Bass 1260 cab that chuffed badly because that slot port was too small. I'm sure they sound very good in the LoPhat cabs but in WinISD the response seems to be down -2dB under 120Hz versus either the 3012LF or 12MW/ND. EQ on the amp can adjust for that but I could see a perceived voicing difference between these drivers.

Originally Posted by billfitzmaurice > As to the 12MW/ND, it's a good driver if paired with a midrange. But like most of Beyma's offerings it doesn't have the rising midrange typical of drivers designed specifically as musical instrument woofers, so it might not meet expectations when used alone.

Beyma offers them in the FR12A/1 and FR12B/1 two-way cabs which cross the 12" woofer over to a HF horn around 1600 hz. I was considering the 12MW/ND with the Faital W6N8-120 crossed around 800-900 Hz but most users are over in Europe and there is no application guidance, tech support, or posts from satisfied users here in the US so I decided not to go this way.

What's really driving this for me is the voicing on that Faital W6N8-120 mid. The slight dip between 1-3 khz to keep the mids smooth, slight treble kick between 5-7 khz to give it some air, and the extended high end seem to make this an ideal driver for a woofer/mid 2-way bass cab. There are many satisfied kappalite 3012LF users and this woofer/mid pairing has some testimony as being a good match so I decided to go ahead with the 1212_66 pictured above using 12mm Okoume marine ply instead of Nidacore. Final dimensions and bracing will be adjusted for this and I'll start a new post for this shortly.

[rpsands]

Dude, the W6N8 is as sensitive in the midrange region as an Alpha 6a which is 1/2 to 1/3 the price. EQ it

Or, a 6nd410 instead of like 3 W6N8's, and a little eq.

[5StringPocket]

I have the 6ND410 in a pair of nEarful 15/6/1 cabs with the 3015LF. It's a powerful mid and it takes two of the Faitals to give the same output but there is a difference in the voicing which I want to explore. The Faital's are supposed to have a sweeter and more extended top end than either the Alpha 6A or 18Sound. Two 3012LF/W6N8-120 in a slightly larger cab versus the 3015LF/6ND410. Larger, heavier, and more expensive but it will also have a little more output and different voicing. See Alex's comment on his Big Twin:
Barefaced Bass - Big Twin
I think it will slam.

[greenboy]

"Sweeter" is a matter of opinion (subjectives are a bass player thing aren't they, but lots people love various drivers), and heavily influenced by crossover design. I'm not trying to dissuade you by the way, just offering that up.

Anyway, once you get into obvious non-pistonic behavior, you are just as likely to have non-pleasing (to some ears anyway) phase flipping in the off-axis right about where the on-axis is icepicking.

Note that the Big Twin and 1212/6 are on the same page.

[rpsands]

What GB said.

If you are seriously concerned with what it sounds like above 3khz or so, get the tweeter.

[5StringPocket]

Every cab I own has a horn. I really want to hear what this particular Faital mid sounds like in a 2-way system with a paper cone top end. "Sweeter" is definitely a matter of opinion and subjective, refering to the description in post #10. Agreed, the crossover heavily influences the pairing. This is a proof of concept cab for me with lightweight construction and this particular driver pairing but I'm not using anything that hasn't already been proven. I got a 1000 watt 4ohm crossover from Ralph Patterson similar to the one in the LDS cab owned by Deb for some time and the woofer box is the 1212/6 reshaped slightly to house the dual 6.5 drivers. The Baer ML212 uses this dual Faital W6N8-120 mid layout with Roger's custom 12's but I would think that above the crossover region the top end would be similar and the alignment should work. I don't know exactly how this will turn out but have enough confidence in the design, construction, choice of components, and past experience to forge ahead.

[R Baer]

I can tell you this much. These mid loaded cabs have a different vibe. As with all thing different, they will appeal to some players and not others. The reason we developed the ML series cabs isn't because we feel that they are superior to tweeter loaded designs, we just wanted to offer something different to players that don't care for the sound of tweeters. Before designing the cabs, we talked to a lot of bassist and were surprised at just how many players turn their horns completely off. The mid loaded designs offer an alternative to just turning off the tweeter.

I'm not quite sure I would use the term "sweeter", as these cabs can sound quite aggressive in the upper mids. As for the Faital's, it all depends on what you are going for. I also like the Celestion NTR06-1705B in our cabs. The difference being that the Celestion will give you a great 70's, Earth, Wind and Fire type slap tone, while the Faital will reach a little higher and provide a bit more modern tone.

[5StringPocket]

I'm expecting a bit different vibe with this mid loaded cab versus a tweeter loaded design and understand the upper mids could be aggressive. What I'm looking for is a tone that is meaty and solid with good articulation from the lows to the highs without a hole in the mids. If the Faital will reach a little higher and provide a bit more modern tone that's good.

I'm considering a switchable -1.8dB pad if the Faitals seem too hot versus the 3012LFs but want to see how the balance sounds without it first. I want to try my Genz Streamliner 900 with this cab because it is good at taming aggressive mids and has nice warmth, focus, and enough headroom to push those drivers.

[Bass Unique]

Originally Posted by billfitzmaurice

That's not actually the case. It's not the position in the cab that makes a difference, it's the width to height ratio of the duct. If that's very high, as in a 24 inch by 1 inch duct, there's more effective length due to the increased friction drag on the air column. With a more typical shape the difference is slight.

-10 This is incorrect. Although the aspect ratio of the duct dominates (only at high excursion), it should be assumed that a reasonable ratio of no more than 3 or 4 :1 is used by good design, then what was stated about position in the cab does make a difference at all volume levels.

The extended sides (particualrly if there is three) using the cab internal walls does lower the tuning. To a lesser extent, putting the slot port at floor level can also make a difference. Friction is only really making a difference at very high excursions.

If you like, setup a little experiment with a narrow slot port and measure the impedance curve at low and high level, it would only shift the frequency of tuning when there is a high excursion if it is to do with friction. If the tuning remains stable, there was little effect. Besides, if there is a significant shift in frequency because of this, your port area is massively under estimated anyway and the chuff will be more of an issue.

[billfitzmaurice]

Originally Posted by Bass Unique

-10 This is incorrect.

My comment was based on my direct experience with cabinets that I built and measured myself. I have found a round duct in the middle of the baffle to measure almost identically to a triangular duct of the same length and area located on the cabinet corner. I've also found a shelf duct in the middle of the cab to measure identically to a shelf duct on the cabinet edge. I've only found a significant alteration to impedance and response when the duct had a very high aspect ratio, and it would do so no matter where it was located within the cabinet.

[Arjank]

Originally Posted by billfitzmaurice

My comment was based on my direct experience with cabinets that I built and measured myself. I have found a round duct in the middle of the baffle to measure almost identically to a triangular duct of the same length and area located on the cabinet corner. I've also found a shelf duct in the middle of the cab to measure identically to a shelf duct on the cabinet edge. I've only found a significant alteration to impedance and response when the duct had a very high aspect ratio, and it would do so no matter where it was located within the cabinet.

Allthough I never tested it myself with measurements it is widely known that when you have a shelf-like port (with the width of the cabinet) the placement in the cabinet will affect the tuning. When the shelf-like port is at the bottom of the cabinet and it uses the bottom panel of the cabinet, the tuning will be lower.
The are programs that take this fenomenon into account when simulating e.g. Boxsim. Boxsim needs to know ALL the internal cabinet dimensions and the position and shape of the port to calculate the tuning frequency. When you fiddle around with the values you can see that is has some impact, the tuning frequency can change several hz. What also has some impact is the distance from the back panel to the port.

Bill, you have some knowledge of Akabak, you should be able to simulate it...