ALPAIR 10 FR Focus on Listening experience

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The Alpair 10 FR (full range version) appears to be a killer on paper and perhaps THE full range speaker many of us have been awaiting for a long time (extended response at both ends, linear response requiring no intervention of any compensating notch or other filter nor of a complex enclosure to compensate the lack of bass - or excess of mid/hi frequencies etc...). Don't misunderstand me, I love Fostex, Lowther and other FR speakers as well but usually compromises are to be made and personally I never managed to get used to the slighty nasal paper sound (a matter of taste) although I believe paper remains one of the best materials for FR speakers. OK, in terms of sensitivity the Alpair 10 does not play in the same league as paper cone speakers but, for those who can live with between 85 and 90dB/1W/1m...

Now the question: Assuming most DIYers are more or less clear now on the possible types of enclosure and load etc.
HOW DOES THE ALPAIR 10 FR ACTUALLY SOUND ???

I propose to devote this post to the listening experience only, after a brief description, of course, of the enclosure/load used (there are other posts discussing the different types of enclosures).
 
Replaced my CSS FR125's on OB with these coupled to an Alpha 15 (MJK Article--thanks Martin!) Have thrown everything in the music server at them and have no complaints. They are well beyond the FR125's with a much better high end. I would describe them as accurate/ nuetral probably close to the Jordans. Cannot compare to any other fr's------.

Pete
 
Jim Griffin's experience with an MLTL

In another thread, I found Jim Griffin's report in those terms (I've left out some bits and hope he will forgive me - full text available at http://www.diyaudio.com/forums/showthread.php?s=&threadid=137585&highlight=):

Quote: "Recently I designed and finished a MLTL with the new Mark Audio Alpair 10 full range driver. (...) The 4 inch long port tunes to 37 Hz. I found that lengthening the port tube to 5” will lower the port tuning and the F3 point a couple of Hzs I’m using the 4” port for my prototypes. The overall external box dimensions for my enclosure (with 0.75” thick material) are 47” H x 7.5” W x 6.75” D. The internal dimensions are: length (top to bottom) 45.5”, driver distance from the top 15.5”, port distance from the top 44”, with a straight cross-sectional area of 6” wide x 5.25” deep, stuffing density of 0.50 lbs per cubic feet, and port radius of 1.03 inches with a port length of 4”. (...)
Well how do they sound? I completed their assembly a week ago and initially I ran the speakers without any filtering. I was very pleased that the Alpair 10 MLTLs produced great sound from the start even without baffle step compensation. Bass was in adequate quantity without any baffle step compensation if the boxes were close to the wall. Later I moved them out in the room and added 2-3 dB compensation (a parallel network of a 1.5 mH coil and 3 ohms resistor in series with one of the terminals). This network created a sweet yet neutral mix for my old favorites. Vocals are spot on for both male and female voices with no echo or sibilance. The high frequencies are there but I’ll take additional measurements after break–in and decide whether any other filtering will be needed.

Well how does the Alpair 10 compare to the Jordan JX92S you may ask? The Alpair 10 tends to need a little larger enclosure volumes than the Jordan driver which I saw in simulations in sealed, bass reflex, and MLTL models. The larger Xmax of the A10 yields a little lower bass and higher overall SPL versus the JX92S. (...) The Alpair’s sound is comparable enough to the Jordan so that most users will be able to achieve that single driver magic at a lower cost. Jim"

Chris.
 
Ray0's experience with approx 15 liter BR"

In another thread, RayO reported as follows (I cut out some bits - appologies - , full text available at the following thread: http://www.diyaudio.com/forums/showthread.php?s=&threadid=130976&highlight= see post 24)

Quote: "I received a pair of Alpair 10 Full Range drivers a few days ago and installed them in a (thrown together) bass reflex enclosure. The internal dimensions are 35cm High x 18cm Wide x 22cm Deep with a port that's 4cm Dia x 14 cm Long. I used about 20mm felt damping on the top, sides, back, and a bit between the driver and the port. (...) After a few minutes of listening to various samples of my music collection and experimenting with the position of the speakers, I put on a Diana Krall album and quickly found myself immersed in the music. I wasn't listening to the speakers (they quickly disappeared) I was listening to the music. It felt like I had a front row center seat and she was right there, in front of me. I could close my eyes and visualize where every instrument was on the stage. I could hear the brushes on the cymbals, her every breath, when the guitar player slid his fingers to a different position, I could go on and on but I'm sure you get the idea.

Another thing I was pleasantly surprised with was the ability of these little gems to play *LOUD*. In my humble opinion, not only do these drivers match or beat the Jordans in accuracy, they can "crank up the volume" too. I put on some good old rock and roll and couldn't resist the temptation to see what they could do. Well... They can go a lot louder than *I* want to listen to and they can do it without getting "harsh" or "muddy". In fact, they can comfortably handle everything my little old Arcam Alpha 6 can throw at them and serve it up clear and clean.

Before I started this project, I was thinking about adding a sub to fill in the bottom but now, I don't feel like a sub is necessary at all. I don't know how they did it, but the Alpair 10 truly deserves the title of "full range driver". The base is tight and defined with no hint of "boom". A bass drum sounds like a base drum and when the musician plucks a stringed double base, it *doesn't* sound like an electric base guitar."
 
Here are my **preliminary** impressions with the Alpair 10FR. They are brand new and will certainly evolve as the break-in process goes.

Set-up: MLTL enclosures, slightly modified compared to the plans published on this forum, Hafler 9505 amplifier, DACT 24 position 10kohms volume control, Cayin CDT17A player.

In their new state, the sound is a bit bright to my taste, but this is expected to change. I've added a roughly calculated serial filter to equalize slightly the frequency response and understand the Alpair's personality.

Well, the Alpairs have no real personality and are very neutral. No metallic, crispy or other nasal or funny sound.

They are not as dynamic/rythmic/expressive as lighter paper cones the same size, but they are not slow or boring either. Sound is quite articulate.

On paper, the frequency response drops pretty quicly out of axis above 8 kHz but in practice I find this is not noticeable at all. It should even be an advantage when positioning the speakers to compensate any mid-high frequency emphasis that could possible remain after breaking-in.

Violin, voice, flute etc. come out without particular unpleasant harmonics (at least I did not notice any so far).

Tridimensionality is OK, not reduced nor excessively deep.
Mid and high frequencies are very clean, higths are detailed and well differenciated (e.g. metal percussion test). Mids lack a bit of resolution (at least compared with high sensitivity speakers): e.g. breathing of musicians is not perceptible - see SL Weiss: Sonatas for Lute (Naxos Editions, vol.1).

Tonal balance: is momentarily influenced by the use of the equalizing filter; no fair statement possible yet.

The bass comes as a *big* surprise for a driver that small (my reference points that I own are Elac 310 and Fostex FE 103S for the minies, and large self made 3 way 400liter enclosures for the bigies). Using a no-yet-optimized MLTL load, and despite the drivers being new, after a few hours the bass is quite articulate and goes amazingly deep even at low levels, and louder without the speaker reacting badly (test: Petra Magoni/Ferrucio Spinetti "Musica nuda" - any track, Andy Summers "Charming Snake" track 8 Passion of the Shadow - the bass-waves are clearly perceptible!, Senem Diyici Quartet - Track 5 Dolama Dolamayi: dry and articulate accoustic percussions). On Christian mac Bride's "Getting to it" - Splanky, the different double-basses are easy to follow.

Max output level can be quite high for the size of the drivers, even in a larger listening room (40sqM in my case, rather damped). Progression in dynamics along the volume level increase has its limits at some stage, inevitably, but I feel no frustration. Live music experience is possible.

My preliminary conclusion: again, I find this is a very neutral driver that can be listened to for hours without fatigue nor frustration nor permanent questions as to what is right or wrong on audio-earth. A good solution for late evening listenings.

More to come soon (tonal balance, versatility on musical genres etc.).

Chris.
 
When it comes to comparisons between the Alpair 10 and the Jordan JX92, their frequency response looks very similar with the same slight rise in the mid/high frequencies, at least if I look at the graph available here for instance http://www.ejjordan.co.uk/drivers/jx92.html and those that a German DIYer magazine has measured for the Alpair 10FR (not the official curves on the Mark audio website which look quite "smoothened" in the high frequency. I presume that as usual it all depends on the way the speakers are measured).
The TS parameters also don't look radically different.

My listening tests with the Alpair 10FR in a MLTL continue in the meantime. I have the feeling that after several hours including with some heavy levels "inputed" I could now almost leave without any serial frequency compensation circuit, but off axis listening still gives a better tonal balance in that case. The serial RLC filter slightly evolves: 0,47mH//2,2R//1,5 or 2,2uF. It seems it will be difficult not to keep such a circuit according to my taste if listening is on-axis.
The increased mid-high freq level also tend to hide a bit the quality and volume of the bass response without EQ.
Compared to what I'm used to, the level of resolution on small information has not evolved (increased) yet. The breathing of musicians on certain classical recordings, the piano pedal game on Diana Krall or evening-grasshopers singing on Alan Taylor's "Roadhouses and Automobiles" track 1 are difficult to notice/identify. But the rest is just great. I still need more tests, also with more complex, orchestral music etc.
 
Alpaier 10 Updates?

This thread has been quiet for months. I'm curious if users find much
change as they break in. I'm not so sure metal cones would change much.

I've put a pair on open baffle and not found much to like so far as a 200Hz
on up. much better when I add a tweeter in. Hopefully they will improve.

I'll be patient and maybe put together a ML-TL
 
I've found a significant change for the better during even a 6 month period. Or so it seems. Highs get clearer and bass gets deeper. I have a pair in 10 litre sealed enclosures with no BSC, notch or anything. However I'm thinking about maybe putting together a BSC when I get the time, but with no more than maybe 2db attenuation.. I think it just plays beautifully..
 
My Alpair 10FR speaker was laying silent for some time. I was working on my main system, a totally different approach (2x 15" in the bass etc.), and deployed huge efforts to get a pair of JBL2392 cinema horns with the 2490H driver - I eventually succeded and decide to do things nicely and less DIY-stylish for a change, built a pair of OnkenW for the woofers and will take over the tweeter from the previous system (SA 8535 or Beyma TPL150H - will see). As I said, a totally different approach.

Now, the interesting thing is the following. I haven't had music in my ears for a few months and while the new bass enclosure's 3rd and last layer of paint is drying and since there is some space again in my listening room, I reconnected my Alpairs. Perhaps it's appropriate to add that they're from the first generation as I've seen that MarkAudio has now launched a new version which measures totally different in the trebble. Moreover, my Alpairs have still not reached the 50 or 100h of service, so I assume the burning in process is far from being complete.

At first I connected them directly to the amp (a 500W/channel studio amp which is not reputed for being sweet and mild in the mid/high frequency). My first impression after such a long time was immediately: "sounds like my friend's Martin Logan electrostats". I put on GianMaria Testa and a few cool wave albums of my wife's which emphasize the vocal range and are a bit (positively) "crude" at times (Budam, Ray Lamontagne etc). I was surprised by the very pleasant brightness, with lots of details and air around the speakers (listening distance about 3 meters, first wall at 2,5 meters distance minimum). After some time, I missed the bass which the speaker was able to according to my memory and it was definitely a too much on the bright side. I can't remember the Equ filter I had stayed with last time, so I picked the standard 1,4mH coils+parallel 2,2ohms and put them in the + signal line. "Ahhhh. Better!" Tried a few other but close values and did not obtain very significant changes (at least not those I'm used to when working on large 100dB+ speakers).

I spent an hour or two, drinking a good red wine from South France, enjoying 2 or 3 more CDs. Turned up the volume progressively and noticed that the subjective balance further improved. When I had reached a fairly high level and a sound volume that I found impressive for the Alpair's size (comparing with the first gen. Fostex FE103S in a similar but smaller BR enclosure, and the speaker whose name is my alias), I thought for a few seconds "what the hell do I need the Onken and JBL and all that big fat equipment"...But just for a few secs of course as nothing can replace the slam and dynamic of a large system.

Also, I was surprised by the amount of signal I had to put in to obtain a clean loud signal, judging by the position of the knob of the passive volume control box. The house would be rattling by now had I wired up the main system, but it shows that a big amp can be worth trying on these Alpairs (I believe a 30-50 watter would have gone into some early saturation). OK, with the filter, average sensitivity is certainly not anymore at 86-88 but rather at 83-85 or so.

Sorry if I was so long. Haven't posted for a while and I probably needed to empty my bag.

BTW: I would love to hear what Equ component values others have tried.

Cheers to all.

Chris.
 
Hi Elac310, Guys,
Nice to read about the experimentation on the Alp10's but I must sound a warning note. Please please take extra care when using any Alpair on large output amps. The risk of over-driving is significant. Like nearly all full-rangers, Alpair's aren't designed for high power applications.

The Alpair's X max's are relatively wide compared to many other full-rangers, this feature is designed for a non-linear "peak loads" only. For example the roll of drum in orchestral rendition , Not for continuous "rock & roll".

A general guide for matching full range drivers to Class A/B solid state is: Multiply a full-range driver's nominal rating by 1.5 to 2 times. For example, Gen. 1 Alpair 10's @ 40 watts (40X1.5 = 60 and 40X2 = 80 watts). Or use the driver's peak rating and multiply by 1.2 (80X 1.2 = 96 watts). This gives you the max output rating for the amp (per channel RMS at same or close Ohm rating). Full-rangers with efficiencies of +90 dB with coil diameters of up to 25.4-mm (1"), class A/B ratings as little as 40 watts are likely to be sufficient. Similar sized full-range drivers with efficiencies of less than 90dB, A/B amps up to 100 watts should be OK.

A word of caution. Some makers (mainly large OEM commercial grade makers) are showing driver rating using IEC and similar. These ratings look good but it's an inappropriate use this data. These testing regimes focus on "destruction" limits rather than usable operational ones. As a rule so thumb, divide a rating of this type by half to give you a more realistic peak usable load figure for a driver.

Here's a useful site: Speaker Selection and Amplifier Power Ratings

The Gen. 2 Alpair 10 has the multiform cone design. It will take a little more power over a short period, but still needs care. The Matsubara san Nomex rear suspension is ultra thin so requires careful running in. This driver along with the new Alpair 6 is now being sent to dealers. I'll be posting final specs on the forum all being well next week - thanks.

thanks

Mark.
 
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Alpair 10 update

After previously noting some dissapointment I should comment again. I worked out my open baffle prototype eventually using the NEO3 PDR and really liked it. More recently I have been working on my DCX2496 to really get the OB going. I put the Alpairs in some small sealed boxes just for the time being and was really surprised how balanced they sound, didn't seem to need a BSC. Maybe I'm not an OB guy afterall.
 
Mark,
i'm driving the alpairs 10 with a t-amp which will make something like 10watts per channel, still with some pop compressed music like say amy winehouse i can see the drivers travelling hard.

the question is: should i fear to damage the drivers even if i'm well within the power ratings? or will the driver just clip and distort but preserve itself from damage when within the power rating stopping its travel?
 
The Gen. 2 Alpair 10 has the multiform cone design. It will take a little more power over a short period, but still needs care. The Matsubara san Nomex rear suspension is ultra thin so requires careful running in. This driver along with the new Alpair 6 is now being sent to dealers. I'll be posting final specs on the forum all being well next week - thanks.

thanks

Mark.

Arrgh ... That's a spanner in the works. I had finally settled on getting Alpair Sevens for my girlfriend's speakers - it was a choice between the 6, 7, or 10 size - and the 7 looked to be the newest and most refined. Until now. With three really tempting options I have to decide again!

(... congratulations on the launch! Few things are as satisfying.)
 
Currently listening to a pair of Alpair 7's in appropriately sized Fonken cabinets, matched with a pair of Planet 10 Fonken woofer cabinets, driven by a pair of plate amps. Cross over at 80 Hz as a line level to the Alpairs, just 6 db, driven by a 40 watt AudioPrism amp.

The combo is powerful, deeply detailed and extremely musical. I cannot imagine a female, most of whom are more interested in the beauty and majesty of music, wanting anything more. Even the 7's running without the bottom octave and a half are superb.

Bud
 
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