[Chops]

Anybody have anything to say about the Mark Audio drivers, the Alpair-10 in particular?

From doing some Google searching, it looks like a lot of people use these drivers without the help of a "super tweeter". This is what I would want to do as well. No tweeter.

Also, being that these use a type of alloy cone (metal), is there any known issues about "ringing" at certain frequencies which is very common on normal aluminum cone drivers?

[Jim Griffin]

I did an open baffle system with an Eminence 3015LF Neo and Mark Audio Alpair 10.2 a few months ago. Actively crossed over and EQ'ed with a DBX DriveRack PA+. Open class winner at the MWAF in Dayton and the SEC DIY speaker competition in Mobile.

Brandonnash (user name) visited my home and heard these speakers and on the AVS forum (DIY speakers) he commented:

"When we started listening to those (open baffle speakers) I brought a CD with a lot of music I was familiar with and the first thing that jumped out at me was the incredible image they threw. I know everyone has heard the phrase "it was like [insert artist name here] was in the room with us", but this was the best example I have experienced with my past with speakers. The best word I can think of describing the sound from these speakers is holographic. The sound stage was incredibly wide, the imaging was spot on, and there was depth that extended all the way back to the wall even though these speakers were 6 feet from the wall. I was very impressed hearing these speakers. Jim correct me if I mislabel the drivers, but I believe they were Mark Audio full range 10 2 and the woofers were 15" Eminence pro audio drivers using neo magnets mounted on an H baffle. The crossover was an external active that I can't remember the model, but everything worked well."

Openminded--A Mark Audio Alpair 10.2 Open Baffle Project
http://www.diyaudio.com/forums/full-range/192451-openminded-mark-audio-alpair-10-2-open-baffle-project.html

Jim

[Poultrygeist]

No doubt a good driver but too inefficient for most SET amps.

[Guy 13]

No doubt a good driver but too inefficient for most SET amps.

Hi Poultrygeist and all Audio Circle members.
I agree with you,
those Mark Audio drivers are way too inefficient.
Anything below 90db is of no interest to me.
I have two tube amplifier, one is a Decware SE84C+ (SET)2wpc and the other is a Niteshade Audio NS-10 (10wpc) penthode.
That`s why I like some much my GR Research V1 and V2, theyr are 95db and more...
Guy 13
 

[Guy 13]

Hi all Audio Circle members.
I must admit that even if the Mark Audio drivers are inefficient, they look very well built.
Guy 13

[Jim Griffin]

Mmmmm..... All of a sudden driver inefficiency is an issue.  I haven't heard that Chops is limited to an SET amp in this thread so a Mark Audio Alpair 10.2 (87 dB sensitivity) may be what he wishes to consider.  Especially when it has an Xmax (one way) of 8.5 mm!   

[Chops]

Mmmmm..... All of a sudden driver inefficiency is an issue.  I haven't heard that Chops is limited to an SET amp in this thread so a Mark Audio Alpair 10.2 (87 dB sensitivity) may be what he wishes to consider.  Especially when it has an Xmax (one way) of 8.5 mm!

This is very true Jim.

In fact, I will be powering the 12 slot loaded Peerless India 8's with a pair of GR-Research SA-1 amps (six 8" drivers per amp), then I'll be powering the Alpair 10.2's (which I just ordered this morning after reading through that post and link above) with my Monarchy Audio SM-70 Pro. It's Class A output with a massive 25 watts into 8 ohms. More than enough for my needs, especially when I'll be crossing them over at around 200Hz 1st order passively. The SA-1 amps will easily cross the 8's over at around 100Hz or so at I think is also 1st order. I'll have to write Danny about that.

[xecluded]

I am using a vintage EV SP12B with a Fostex T90A supertweeter over top a Alhpa 15A H frame.  This is a mighty fine system.

I want to try the same setup.  Can you give me the schematics of your crossovers or tell me how you set it up.

[Jim Griffin]

Chops,

You'll like the Mark Audio Alpair 10.2.  As a single full range driver I've used it in a MLTL configuration which has a very nice sound.  But the open baffle arrangement with the big woofer and 10.2 is really sweet.  25 watts will yield just over 100 dB SPL for mid-range and above coverage.  That coupled with the lows covered by the slot loaded drivers should be pleasing. 

I use an active crossover (at 200 Hz) on my project.  The inherent ability to have a 28 band EQ within the dBx DriveRack PA+ crossover enables me to have exceptional control over the frequency band.

Good luck on your project.

Jim         

[Badwater]

I want to try the same setup.  Can you give me the schematics of your crossovers or tell me how you set it up.

High pass 2nd order on the EV at 200, single 1uf cap on the tweet with L-pad, which probably isn't necessary.  Plate amp to drive the Alpha. Need an amp which will give you a 200 hz 2nd order.  You could probably let the EV go full range. Visit Martin King's website for more info.

[planet10]

Monarchy Audio SM-70 Pro. It's Class A output with a massive 25 watts into 8 ohms

I had an opportunity to use some of those monarchy on a set of Fonken. Very nice amp. Wish i could have afforded to take one away.

A10.2 is a very nice driver. For mid-top finesse the Alpair7.3 is even better.

dave

[xecluded]

High pass 2nd order on the EV at 200, single 1uf cap on the tweet with L-pad, which probably isn't necessary.  Plate amp to drive the Alpha. Need an amp which will give you a 200 hz 2nd order.  You could probably let the EV go full range. Visit Martin King's website for more info.

Many thanks.  I will try that.

[Chops]

Chops,

You'll like the Mark Audio Alpair 10.2.  As a single full range driver I've used it in a MLTL configuration which has a very nice sound.  But the open baffle arrangement with the big woofer and 10.2 is really sweet.  25 watts will yield just over 100 dB SPL for mid-range and above coverage.  That coupled with the lows covered by the slot loaded drivers should be pleasing. 

I use an active crossover (at 200 Hz) on my project.  The inherent ability to have a 28 band EQ within the dBx DriveRack PA+ crossover enables me to have exceptional control over the frequency band.

Good luck on your project.

Jim       

Hello Jim,

I'm trying to keep this project as low cost as possible as well as simple as possible, hence going the passive route on the fullrange. The Onkyo 809 that I'll be using as the "preamp" has the latest and greatest Audyssey software (equalization and room correction), so I'm hoping if there's any EQ'ing to be made, the 809 will be able to make the proper corrections, especially since there's 8 points of measurement within the listening area.

[Chops]

I had an opportunity to use some of those monarchy on a set of Fonken. Very nice amp. Wish i could have afforded to take one away.

A10.2 is a very nice driver. For mid-top finesse the Alpair7.3 is even better.

dave

Yes, they are nice little amps. That's for sure. I almost bought a second one shortly after buying the first one, but it had those funky gold wire rack handles and the writing on the face plate was a little different, so I passed. Maybe one day I'll get another one.

I was considering the 7.3 for a hot minute, but I wanted to make sure I had a driver with ample oomph and handling on an OB since it will be dipping down around 100Hz. Now watch Mark Audio come out with a brand new 10.3 right after I bought these 10.2's. Isn't that how it always works out? LOL

Anyway, speaking of the 10.2, are there any known resonance issues with it that I should be aware of, any funky cone break-up, harmonic distortions, etc, etc that I might have to attend to? The reason I ask is because I know how metal cones can act which is why I have always tried to stick with paper/organic cone materials.

[planet10]

Mark's metal cones are considerably developed from other people's, and use technology unique to him for making them.

dave

[jacozz]

Hello Chops!
I have experience with Visaton B200, and Tangband W8 1772 in open baffle.

I have tried both in my open baffle with active 15 woofers.

In my opinion, Visaton B200 is a descent midrange speaker, (in my book, not really a fullrange driver), because of muddy treble and very shouty upper mids. Stay away from this driver, unless you are planning to add a tweeter and cross it lower than 2k!

The Tangband 1772, on the other hand is the best fullrange driver I have heard to this date!
Part from the usual fantastic midrange, (most fullrangers shine in the mid), but also It's, smooth without noticeable breakups and peaks, + extended highs, quite the the opposite from the Fostex and the Lowther offerings.


The 1772 is a bit more efficient compared to the 1808, and you don't really need the higher QTS anyway, (Bass is handled by the dedicated woofers).

 
I also have the Jordan JX92S, (using them in bassreflex, as computer monitors), they are pretty good with extended frequency range, but suffer a bit from breakup modes in the treble region, and efficiency is quite low.

Mark Audio drivers, I never heard, but they got a lot of praise around the web. (But they are not making any 8 inch fullranger. A12 is 6.5 incher.

/Jacozz

[Chops]

Mark's metal cones are considerably developed from other people's, and use technology unique to him for making them.

dave

I imagine you mean "over" developed?

So no issues? Some issues, different issues?

[Chops]

This seems to be a dead topic, and I still haven't been able to gather anymore information on the slot design. Mr Pass is MIA as far as email is concerned. This is all kind of disappointing and takes the excitement out of trying to start this project. All the drivers have been sitting, untouched.

Just today I finally opened the package up for the Alpair 10.2's. Normally I would have torn right into them as soon as I got them, but there's just no drive to motivate due to the lack of anything on this thread and a couple others. The last bit of information I got on another thread was a link to a spreadsheet for OB calculations that I have no clue how to work.


Anyway, I cut a couple of 0.50" BB ply, 12 x 12 baffles with the driver opening right in the middle. With a couple of metal "L" brackets each and some little rubber feet, these will be used for the 500+ hour break-in period for the 10.2's. I'll be powering them with Dayton's version of the little SI T-amp, the DTA-1. Not the pretties things (the baffles that is), but they'll get the job done.

On a little bit happier note, the Alpair 10.2's are beautiful, very well made drivers. Even my girlfriend likes them! She's glad I chose the gold version.

[JohnR]

Lack of anything on this thread?  Your project isn't going to build itself, we're waiting for you!!

[Chops]

The thing is, I don't have the luxury of building multiple baffles to "find" what's going to work and what's not. It's gotta be pretty much a first time thing since I'll most likely have someone else doing the majority of the woodwork. And I'm still not certain what the actual insides of the slot looks like. I need to know this stuff before I can move forward at all.

As for right now, I just have the break-in baffles up and running. The Dayton amp is running off of the Zone 2 pre-outs of my Onkyo TX-NR809 receiver. Unfortunately, HDMI signals are not passed through, so when we're watching TV, there's nothing going to the A10.2's. However, all other times, I will have vTuner playing random music.

At any rate, here's a few pics...