Alpair 6 Desktop TL

[TeLHannos]

Hi,

There are these cool desktop TL designs from Henkjan with Markaudio drivers - the alpair5 and the (css) el70.
I already have a needle-tl with a Alp6 and I really like it's sound - and there's another pair of alpair6 at myhand AND I need a computer speakers, since headphones all the way isn't my thing, I realized.

So I wonder if it would be doable to construct a compact size TL with the Alpair6. I've found nothing on the web, so I any hint would be awesome!


Kind regards,

Hannos


PS: I tried to enter the T/S-Parameters of the Alpair5 into the excel sheet provided here: http://www.diyaudio.com/forums/full-range/162362-help-new-guy-tl-enclosure.html
But the results for S0,SL and length greatly differs from those I measured from the Alp5-TL construction plan. But I couldn't find out what the TL's tuning frequency is (maybe around 70Hz). I guess it's far below the drivers fres (125Hz). If this is the case, shouldn't be that big difference a problem concerning the whole TL principles?

I have so many questions about TL's, but the TL Theory Papers from M.J.King seems so complicated...

 

[Henkjan]

the horn-reflex design I did with the Alapir6 is not an option?

I could do a few sims with the Alpair6 for a similar styled desktopTL later this WE (provided I win the my fight with my PCs which are causing a lot of manure lately)

 

[planet10]

Henkjen,

I have a feeling you might find the EL70 TL a good starting point.

dave

 

[TeLHannos]

Hi and thanks very much for your responses!

I didn't know that you did a horn-reflex design. I couldn't find it on the forum. Maybe you can point it out.
It would be awesome if you could construct a design.

In the meantime I tried my luck with my own design and already finished the prototype speaker box.
I'll post all relevant stuff tommorow, so maybe we compare it than.
(I didn't have the "King Sheets" btw, just the excel, so it's gettin interesting )

I'm quite happy with the result - after changing the sonofil stuffing a few times. My prototype still isn't going as deep as the needle, but having a peak at ~55Hz. After 55Hz the pressure level is going down and hits the same level at ~90Hz. This behaviour is a little annoying... missing many of the fundamental tones, the needle on the other hand sounds a little fatter.

The alp 6 seems quite loud from 100Hz-500Hz if I listen to single frequencies.
The needle don't show this behaviour. Can this be because of the trap cirquit at ~2000HZ in the needle ?!?


Kind regards,

Hannos

 

[TeLHannos]

Here are two photos and the excel tables.
The design is quite like the alpair5 desktop tl. I point to the driver position. I guess it's not a big problem if you shift the mounting of the driver from one side to another, as long as the position on the line length is garranteed.

To the excel table - I brought in a limiting factor to the "line length" because of the dampening material. I hope this wasn't a mistake.
But I guessed that at this point the dampening isn't taken into account by the excel sheet.

@planet10:
The el70 design I considered too big for my desk.
It has to be quite flat (16cm max) and max. 43 cm high. The front aspect wasn't of much interest but the excel sheet tended to the golden ratio...


Kind regards,
Hannos


PS.: I had a small error in my excel sheet. The description for the fields "Correction cross line section" and "Correction of the tuning frequency" were switched. I don't know if this had been fixed at this point.

 

[chris661]

How does it sound?

 

[TeLHannos]

See my secound post in this thread.
There's room for improvement

 

[TeLHannos]

@Henkjan:
I've found your easter project 2010 .
Maan, if I knew about this before I certainly have built these.
Well, I can still make a computer case or a bird-house out of my box.

 

[Henkjan]

if you still consider a TL, here's a sketch of something worth trying... stuffing, something like 50grams sonofil, 90% in the closed end, remainder in the open end (adjust the latter to tast)