Alpair 10 - Generation 2 - sneak peek

[markaudio]

Originally Posted by mp9

A higher sensitivity A12/more eff coil, i'd like that, and if that's not asking for to much, well it's design is getting refined can we look forward to a alnico option?

Hi Mp9,
I think we can achieve efficiency in the high 80's using the rectangle coil. At this moment we are running the test samples on Tony Wong's 6L6 - 4 watt and his 300B - 8 watt amps with very nice results. The test boxes are simple 12 litre BR's so more performance may be available from better designed boxes.

Certainly, Tony's 4 watter is very sweet on these Alp10 rectangle coil sample drivers, fine for average listening levels in medium size rooms (around 4 X 5 metres).

I'm not sure if the Alp10's would do well on anything less than 4 watts. I have to build these drivers to satisfy the majority of DIYer's, who aren't running flea and candle powered amplification. My aim will be around 87 to 88dB. I was hoping to make 2 models but the vote for the round coil model limits me to making only 1 model driver and sadly, the world economy is still looking so-so.

If any of you DIY guys can organise a "group buy" for 500 or more drivers, I'm very happy to build a specific higher-efficiency model. But its got to be 500 up to be production viable.

Cheers

Mark.

[dwb2]

Hi all,

I tried to post this twice before, it doesn't seem to be showing up. Sorry if this gets repeated!

I am thinking of using the A10s in a closed portion of a BR box with 2-8" for bass. The A10s would not have a filter and the 2-8" would be choked at about 500 Hrz. I don't believe that the FR A10s would provide the kind of "foundation" for music that I like. The A10s would be in a pretty small closed box causing them to roll off on the low end.

I am wondering if this would work for the A7s also since they don't need to cover below 500 Hrz. However, I am concerned about the power handling of the A7s, since we like to play loud sometimes, but think that the closed box will help.

Would using a filter to limit the range handled by the A10s or A7s help with power handling also?

Sorry if this offends any of the FR purists, but this seems like a good way to get very good clarity and detail in the upper range and solid powerful bass.

Any comments would be appreciated!

[planet10]

Nothing wrong with a FAST. (i'm working on an A7 + 4 7" per side, XO 125-250 Hz). Releiving the FR of bass duty sweetens the mids as well as giving a really solid bass foundation.

A small sealed box will give a 2nd order rolloff but i don't think you can get one small enuff to get it up to 500 Hz -- and a box that small could really congest the mids. It will also have a big bump just above roll-off.

For instance A7 in a sealed Q=0.707 box (13.5 litre) has an F3 of 85 Hz. Then a 1st order PLLXO could be added at the same frequency to give a 3rd order roll-off.

2 litre gives a Q-1.215 with about a 3dB bump at ~150 Hz. One could put an XO (for practical purposes way better to be active) up higher than this and roll off the bump up.

So if you want to XO that high (i'd suggest crossing lower) you will need filters.

dave

[dwb2]

Thanks much Planet10!

Any thoughts on the effect of using the sealed box for either the A7s or the A10s and power handling and the A7s verses the A10s? Shouldn't limiting the lower frequency load generally increase their power handling ability?

At what point do you think the sealed box becomes too small, causing mid-range congestion?

Appreciate the help!

[planet10]

Originally Posted by dwb2

]
Any thoughts on the effect of using the sealed box for either the A7s or the A10s and power handling and the A7s verses the A10s? Shouldn't limiting the lower frequency load generally increase their power handling ability?

In theory yes, but with the filter needed to roll off the A7/A10 as high as you want, they should be down so much already that sealed will have a small effect.

At what point do you think the sealed box becomes too small, causing mid-range congestion?

I've found this already happening when i squeeze (4-4.5") drivers into a milliSize box (an acceptable amount, but i wouldn't go much smaller (4.5-5.5 litre)

dave

[SamoR]

When can we expect Alp10 mk2 to be available for purchase?

[einstein]

Originally Posted by planet10

Nothing wrong with a FAST. (i'm working on an A7 + 4 7" per side, XO 125-250 Hz). Releiving the FR of bass duty sweetens the mids as well as giving a really solid bass foundation.

I was thinking the same thing except using the Trio 8 driver (possibly with side firing radiators). Not sure how the Trio 8 is above 200hz though.
How do you plan on boxing the 4 7" drivers, side firing ?

[markaudio]

Originally Posted by SamoR

When can we expect Alp10 mk2 to be available for purchase?

All being well, final assembly will commence around 14th September. Usually takes 3 days. After that, it depends on the dealers. Japan and Germany are fairly quick at ordering. Driver stock for Europe usually goes by sea, Japan by air. North America will also go be sea. Reckon on around mid to end October.

Mark.

[SamoR]

Thank you for quick response. I'm really interested in trying to build something with this driver. Sounds very promising.

Originally Posted by markaudio

All being well, final assembly will commence around 14th September. Usually takes 3 days. After that, it depends on the dealers. Japan and Germany are fairly quick at ordering. Driver stock for Europe usually goes by sea, Japan by air. North America will also go be sea. Reckon on around mid to end October.

Mark.

[Henkjan]

Originally Posted by einstein

.... Not sure how the Trio 8 is above 200hz though.

I've used it (to support an Alpair5) upto 300Hz, and that sounded great