Alpair 12P
140mm Fullrange drive unit </ br> 8ohm single ferrite magnet</ p>
- Legendary full range drive unit
- 7in natural blue uncoated reinforced paper cone
- Operating range to 20KHz –very linear response
- Very low-profile multiform cone for broad directivity pattern
- Advanced low-distortion motor design
- Long-stroke hybrid mono-suspension with arrestor and progressive-rate spider
- Self-damping reinforced polymer basket
Description
The Alpair 12P is the largest full-range driver produced by Markaudio. This driver is a development unit following on from the original metal coned Alpair 12 produced in 2009/2010. Several major design changes make this Alpair radically different from the original in terms of its operation and performance.
Brief Markaudio Alpair series drivers are totally custom designed and built. All components (apart from the magnet) are individually designed and engineered with their own tooling and mould making sets. Alpair drivers are made by highly skilled engineers, they arenʼt “mass produced”.
Key Features
The change to a custom paper cone with a more shallow profile reduces mass and increases dispersion performance. The new cone is only 21-mm deep compared to the metal unit at 26- mm. The 12P employs and new custom CCAW coil with an aluminium/paper wrap, vented, lowmass thin-walled body. The spider is particularly special. Designed by Matsubara San, it employs a new long throw profile set together with a ribbed body to maintain linearity. The front suspension remains the same as the previous model; A design by Lu Yi Ping, its ultra thin wall doesnʼt support the cone. In terms of mechanical load performance, the 12P remains a single semi-free to air driver, possibly a unique design in its class.
Performance
The 12P remains pure to designer Mark Fenlonʼs current criteria which is to make purist, single cone drivers that are full-range capable without the use of phase plugs, co-axial centre tweeters or whizzers. The 12P is 92dB efficient (1w/m2), operating to 22 kHz (-3dB) and having a resonance frequency of 42Hz (+/- 2Hz). The 12Pʼs power-train (cone, cap, coil and suspensions) is mechanically efficient and linear, requiring only modest powered amps to make it perform well. This driver is aimed strictly at the “audiophile” end of the market. Its cone is highly-resonance sensitive so clean low-distortion amplification and source components are advised.
For those listeners who value absolute detail, dynamics and clarity, the Alpair 12P is an excellent candidate. Iʼd like to thank all those who assisted in the design and development process, especially existing Markaudio driver users, whoʼs feedback was instrumental in the 12Pʼs final incarnation.
The recommended Max usable excursion = 5.4mm X 1 way (non linear bass load) and Max power handling = 30 Watts (Nom).
Running in: Carefully run the drivers at low volume using light music (NO artificial signal generation of any-kind) for the first 100 hours. After this period, gradually increase to normal listening volumes with the introduction of music that contains some bass. The driver will reach optimal performance at around 800 hours of play time.
Take great care not to touch the cones, or use any cleaning agents on their surface. Keep the drivers away from strong light as the UV may damage the coneʼs structure.
| Revc | 7.00 Ohm |
| F0 | 42.149 Hz |
| Sd | 147.410 cm² |
| Vas | 43.060 Ltr |
| CMS | 1.369 m M/N |
| MMD | 9.188 g |
| MMS | 10.217 g |
| BL | 7.540 T.M |
| QMS | 1.981 |
| QES | 0.333 |
| QTS | 0.285 |
| LeVc | 53.952 uH |
| No | 0.936 % |
| SPL0 | 91.730 dB |
Additional information
| Weight | 2.6 kg |
|---|---|
| Dimensions | 45 × 45 × 25 cm |
| RE | 7 Ohms |
| FS | 42.149 |
| SD | 147.410 |
| VAS | 43.060 Ltr |
| CMS | 1.396m M/N |
| MMD | 9.188 g |
| MMS | 10.217 g |
| BL | 7.540 T/M |
| QMS | 1.981 |
| QES | 0.333 |
| QTS | 0.285 |
| LE | 53.952 uH |
| SPL | 91.73 dB |
| POWER (NOMINAL) | 30 Watts |
| X MAX | 5.4 mm (one way) |
| colour | Paper |
Gregory Peyton –
Since I have just begun breaking these drivers in, I can only give 4 stars thus far. I have owned a 10P model in the past, which I would easily rate at 5 stars, so I am expecting much the same performance from these drivers.
At present, an open baffle design is being used for break in, but I am planning to use them in a rear loaded horn design. That will likely be in the spring of next year.
What I can say right out of the box is that there is a speed that I enjoy about these drivers that does not produce an unwanted shout with it. That seems to be a common problem with many full range drivers, and is a deal breaker with me.
I was surprised to see what appears to be much the same size cone in this driver as in the 10P. I measured the paper part of the cone at approximately 4 3/4 inches. Bass performance and the rest of the spectrum will be expected to perform at least as well as any other 8 inch driver, but again, time will tell
Gregory Peyton –
This is not my first experience with the Mark Audio drivers. About 1 year ago, I used the 10P in a smaller back loaded horn design. No doubt, I was impressed, But I simply wanted more bass. In spite of that, the 10P had so many promising qualities, that I kept it high on the list for my future project, which was the same back loaded horn, but in a 40% larger cabinet. Well, since the larger cabinet was a given, I figured so was a larger driver. I won’t go into the other drivers used, except to say that they were not average either by any means, nor inexpensive. Once I installed the 12P, the search was over. The fir st driver that I tried in design had way too much bass, period. The 12P was a perfect match in every way. I mean to say that horn loaded bass is impactful and fast, and so is the 12P. The first amp used was a class D design using Hypex type output stage. The 12P took the slam associated with class D and made it beautiful. Ok, so the next amp is a much older design by Carver, the A220. In a word, musical. I am not a Carver fan per se, but that is the sound that I am getting right now. The last and hopefully final amp is a reconfigured Forte’ model 3 which is being remade by an audio engineer who retired from Sudgen of Europe. The amp was a disaster and needed all the help it could get. It should be arriving shortly.
If you want to just skip all of this and get to the last paragraph, just retain the fact that these are some of the finest drivers that I have ever heard. There is a transient response And musicality that are blended together perfectly for my taste. enough so, that I have no desire to try out the other fine drivers left to be used in this design.