Mark audio alpair 5 gen 2

danielnaveen2003

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Hi everyone,

I just finished building the first iteration of a micro open baffle speaker and I am using the mark audio alpair 5 for the high frequencies. Does anyone have experience with this driver? Does it need a lot of burn in time? It just doesn't seem very airy. Thanks!

https://photos.app.goo.gl/UVDPX567hkSEyiJ48

P.S. I have it crossed over at 2000 hz and have eq'd the top end slighting to improve off axis response
 
Interesting setup, do you see any advantage with the push pull configuration compared to single driver OB.
 
Hi everyone,

I just finished building the first iteration of a micro open baffle speaker and I am using the mark audio alpair 5 for the high frequencies. Does anyone have experience with this driver? Does it need a lot of burn in time? It just doesn't seem very airy. Thanks!

https://photos.app.goo.gl/UVDPX567hkSEyiJ48

P.S. I have it crossed over at 2000 hz and have eq'd the top end slighting to improve off axis response


Hello,

I saw the pictures that you have posted and the datasheet of Mark Audio Alpair 5 Gen 2.
Though I have zero experience with open baffle and have never used the driver in question, here are my thoughts:

1. The Alpair seems to go low below 100Hz. Why are you restricting it to 2000Hz? That is waste of money on the beautiful driver and will never sound airy. By not operating it at low end, you are not allowing it to burn-in.

2. What Woofer are you using? Can you give me its specs? Unless you have strong math to support the dual driver arrangement, the end result will be far from optimal. Same goes for open baffle design

Here is what I suggest:
Build a 3.1ltr ported box tuned to 78Hz.. You should be able to get fantastic sound from 70Hz to 20+KHz (Only from the Alpair!)
Build a separate enclosure for the woofer for support below 80Hz.

Enjoy it for a few months and then venture into open baffle only for the Alpair driver, leaving the Woofer out.

Regards,

Ravindra
 
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Hi everyone,

I just finished building the first iteration of a micro open baffle speaker and I am using the mark audio alpair 5 for the high frequencies. Does anyone have experience with this driver? Does it need a lot of burn in time? It just doesn't seem very airy. Thanks!

https://photos.app.goo.gl/UVDPX567hkSEyiJ48

P.S. I have it crossed over at 2000 hz and have eq'd the top end slighting to improve off axis response


On second thought:
In normal application, the two woofers face each other. This helps in reducing the enclosure volume.
Not sure how they will work here with open baffle. May be one on each side of the baffle?
I really am confused at the way it is looking right now.
Something just does not feel right. May be you are trying too many things in this combination.
Is there any reference design for such a configuration?

Regards,

Ravindra.
 
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Lots of responses here, @yogibear your right if I had the luxury of running 15 inchers life would have been very different. But any bigger and my entire living area is going to be consumed.

@Ravindra Desai maybe the alpairs need to run lower to allow them to break in. The woofer I use are GRS 8's. The baffle size of the speaker is limited and hence the front wave and back wave will cancel each other out and due to the small cone size the speaker doesn't start beaming from till about 2000 hz . That is why I run the second driver in opposite polarity to move the cancellation to the sides. The speaker is fully active and the two 8 inch drivers can be moved closer or further to get them timed right. Putting two boxes and have them opposing each other doesn't make sense that's not a ob design anymore that's a bandpass box
 
I have edited my post # 6. Kindly read it again.
Sorry & thanks!!

Regards,

Ravindra.

P.S. Ah! There was no way to see the drivers being run in opposite polarity!!
But still, count my responses about the woofer out as this combination is way above my understanding.
However, my comments about the Alpair are correct.
 
I am sorry, the first picture was not bright on my phone and did not see the two woofers with one behind the other.

Don't do that. Do either Ripole or PPSL or rather see Linkwitz project for a very interesting design using 8 inches multiple drivers for amazing bass and sinlge FR driver. Will try to fish out that design and post link here.

Instead of your setup, putting two woofers on same baffle and running them in parallel and bi-amping the setup (driving dual woofers by one and Alpair by the other ) will give more OB benefits. Try it and you would like what you hear.

I tried putting two speakers on the same baffle if you look closely there is another hole in the baffle, but the bass was pretty bad as it's a small baffle. Ripoles look interesting, then I'll need to put the alpairs in a box to run them at a lower crossover point safely which will take away the dipole nature of the speaker. But then again this is the first iteration the possibilities are endless
 
On second thought:
In normal application, the two woofers face each other. This helps in reducing the enclosure volume.
Not sure how they will work here with open baffle. May be one on each side of the baffle?
I really am confused at the way it is looking right now.
Something just does not feel right. May be you are trying too many things in this combination.
Is there any reference design for such a configuration?
Sir isobaric designs need atleast the pulling woofer in an enclosure, else the spring action from the air released within the chamber will not be there.
I don;t think technically isobaric designs will work in open baffle designs. They were mainly designed to save on space, but there will be a 3db loss unless one of the speaker is wired in reverse polarity. It that case the impedance will drop in half leading to other issues.

I however run a traditional isobaric subwoofer made with two 6.5 midbass driver in my car with good results.

@danielnaveen2003 I have no experience of open baffle designs, but you are clearly under utilizing the Alpair and straining the woofers.
Since the Alpairs are almosr in free air, I suggest you cross them at around 300hz (the best way to arrive at the HPF is to play some thick male vocals and play around the HPF of the Alpair and push it a an octave up from where the sound starts to get muddy.
Also play with the slopes.
 
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Do you have specs on the woofers ?

This PE page has the specs

https://www.parts-express.com/grs-8pr-8-8-poly-cone-rubber-surround-woofer--292-428

@danielnaveen2003 I have no experience of open baffle designs, but you are clearly under utilizing the Alpair and straining the woofers.
Since the Alpairs are almosr in free air, I suggest you cross them at around 300hz (the best way to arrive at the HPF is to play some thick male vocals and play around the HPF of the Alpair and push it a an octave up from where the sound starts to get muddy.
Also play with the slopes.

Fair enough I'm treating the Alpairs more like tweeters. let me try playing around with the crossover point and also give the setup a bit more burn in time.
 
IMHO, the Alpair 5 I have seen in some BLH and ported designs only. Expecting Alpair to go down anywhere near even 200 hz in OB would be a tough call. The 8" GRS woofer is high in Qts and even the sensitivity of the both the drivers is matched at 85 dB but to expect the 8" 85 dB driver to do bass duty is again a tough call.

I think if you want to build a 2 way OB then there are some other good options too.

And again putting those two 8" drivers one behind one other in open air will not be fruitful as you may expect.

OB is mostly build around high Qts, high Senstivity drivers with larger Cone area and on flea power, they are magical.

Just sharing my little experience after many non-stop experimenting and numerous falters......

Still looking for that OB build using multiple 8" drivers, but here some food for thought when you want to used smaller drivers for LF OB duty:

View attachment 28875

View attachment 28876


i have two 10" Iwai subwoofer drivers.
My original plan is the build two separate ported subwoofers like our FM Sadhik.(for movies and I want deep bass with room vibrations:D)
I learned the basics of how to simulate a ported box. But I don't know how to simulate any of the above designs.

just a suggestion based on your guess work.... any of the above designs can give better bass than my original plan (two separate ported subs)
Or....these models are more suitable for clean bass for music .... do these designs need any specific qualities like high Qts etc ?
 
Atleast the first one is pretty easy to build...il give a try

These drivers have very good Fs 28Hz, but Qts is too low 0.26....any way...il give a try.....

If there is a very low probability that 0.26 Qts may work.... Il stay away from attempting...


@danielnaveen2003 sorry if I'm diverting ur topic ...:) it start a separate thread if I build these....
 
I have experience with markaudio drivers. They sing really well. My first pair is 7.3. The second pair I bought (yet to receive) are 10.3. I'm planning to build back loaded horns with them in a small package (work in progress). I've driven my 7.3s in free air. Highs, upper mids are exceptional. That can easily be compared with any high-end speakers. But 7.3 itself falls short in lower midrange. I'm yet to experiment with them in an enclosure. I think the mids will bump up for sure. I believe for 5.3 the off axis response will be better.

Loved to see the minidsp 2X4.

Are you using fx-qudio tube pre?

The amp for subs is QSC if I'm not wrong.
 
I have experience with markaudio drivers. They sing really well. My first pair is 7.3. The second pair I bought (yet to receive) are 10.3. I'm planning to build back loaded horns with them in a small package (work in progress). I've driven my 7.3s in free air. Highs, upper mids are exceptional. That can easily be compared with any high-end speakers. But 7.3 itself falls short in lower midrange. I'm yet to experiment with them in an enclosure. I think the mids will bump up for sure. I believe for 5.3 the off axis response will be better.

Loved to see the minidsp 2X4.

Are you using fx-qudio tube pre?

The amp for subs is QSC if I'm not wrong.

Ya I use the fx audio pre to boost the output from the mini dsp 2x4 for the Allo amp I use. The mark audio drivers have opened up pretty well now and the speakers definitely sound as well I want them to. The grs 8 speakers mounted back to back in inverse polarity have to eq'd to imporve thier low end using the mini dsp. However as mentioned above ripole may improve bass performance further but will kill any performance above 100 hz as they will be totally off axis in a ripole, and can't expect much in that range from the mark audio in a OB setup.

Now that I think of it going three way would have made it perfect, ah well will do that next time.

And the subwoofer amp is behringer inuke dsp 1000.
 
Ya I use the fx audio pre to boost the output from the mini dsp 2x4 for the Allo amp I use. The mark audio drivers have opened up pretty well now and the speakers definitely sound as well I want them to. The grs 8 speakers mounted back to back in inverse polarity have to eq'd to imporve thier low end using the mini dsp. However as mentioned above ripole may improve bass performance further but will kill any performance above 100 hz as they will be totally off axis in a ripole, and can't expect much in that range from the mark audio in a OB setup.

Now that I think of it going three way would have made it perfect, ah well will do that next time.

And the subwoofer amp is behringer inuke dsp 1000.

Great going. After much dillema, I went for dbx dsp+xo combo instead of minidsp 2X8. I'm planning for 3 way keeping Alpair 10.3 as midrange. I just got Nobsound 6J1 tube pre (like the fx-qudio) couple of weeks back. That little box can do wonders
 
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