Alpair 10 Bass + Alpair 5 - Woodwill Japan

[EUVL]

This is the one we listened to at Mark Fenlon's last October :

ALPAIR10¤È5¤Î2¥¦¥§¥¤ - Linfof¹©Ë¼ - Yahoo!¥Ö¥í¥°
http://blogs.yahoo.co.jp/linfof/fold...html?m=lc&p=19


Patrick

[EUVL]

I initially typed in 1-2 kHz, but then I wanted to provoke some discussions, so I changed it to 2-3 kHz.
300Hz is for me too low. The overlapping region is not large enough for the AP5 using first order HP.




Patrick

[Henkjan]

Originally Posted by EUVL

....300Hz is for me too low. The overlapping region is not large enough for the AP5 using first order HP.

in that we agree

[Henkjan]

Originally Posted by EUVL

I initially typed in 1-2 kHz, but then I wanted to provoke some discussions, so I changed it to 2-3 kHz.
300Hz is for me too low. The overlapping region is not large enough for the AP5 using first order HP.

the post to which Patrick replied here went AWOL, so I'll try to repeat what i said there...

Originally Posted by EUVL

IMHO it is not the best way to combine a 5 & a 10. If I were to use combine full range to a 2-way (i.e. I would not want to use the AP10 bass but AP10 full range, or even AP12), I would want to take advantage of the large overlap in the freq spectrum of the two, and use 1st order X'over to retain phase and amplitude coherence. I also would not want to use the 5 as the main speaker, but rather only for the top part of the spectrum. So I would consider crossing at say 2-3 kHz.

crossing that high will imho cause you to loose much of the advantage of a FR driver as the Alpair5, you might just as well use a tweeter then...

If you want to make the filter less complex, I see 2 approaches:

• cross at ~1kHz ist order and time align the drivers. I know a pro designer here that has applied this with success on the Alpair5
• follow the baffle step for the Xover point, as Tony Gee did with his Capella design, and what I did in my FaB4. if you're very lucky you won't have to add a notch for the impedance correction.. (but in the examples given at least the bass driver still needed it, despite crossing over at 500Hz)

or go active as I did with Nesio.

btw: here's the cover of the HH:

BT made a nice round cabinet for the Alpairs

[EUVL]

I was thinking of Jim's Jordan Mini Monitor with Ribbon. Seems to be very nice speaker, except the crossover is not phase coherent. Using a AP5 as tweeter would solve that.

The discussion whether to cross at 1kHz or below or whether at 3kHz or above is more like whether the 10 or the 5 should be used as the "full range" (or main speaker). I tend to favour the 10, if only for less distortion at somewhat higher SPL.

But I guess the only way to find out is to build and listen.

What is your opinion, Mark F ?


Patrick

[markaudio]

"I was thinking of Jim's Jordan Mini Monitor with Ribbon. Seems to be very nice speaker, except the crossover is not phase coherent. Using a AP5 as tweeter would solve that".

Hi Patrick,
Personally, I'm not a big fan of adding tweets to Full Range drivers that can get to 20-kHz @-3dB or so from their SPL. The Alpair 7 certainly does away with the need for a tweet. Adding a tweet to this driver would be sacrilege.

But we live in changing times and guys are adding tweets. If I were to add a tweet, I'd cross above the 4-kHz telephonic threshold, thus utilising what should be the better low to mid emitting performance of the full-ranger.

It also explains why I've been a busy fella tweaking the my new 6.5 woof and tweet to emit flat response so they too can be crossed higher.

A reasonable rule from British Tele-communications (Scott Moose knows more on this) is to cross below 400Hz or above 4000-kHz. I understand their the outcome from years of communications practice is: Don't mess around with the in between frequencies.

Having said this, for many applications it may not practical to cross so low or high. Niwa san in Japan has done some very nice work in BR's with Alp10-Bass and Alp5 crossing at around 1.5-kHz (from memory) with first order. Certainly, from what I've heard from his sample system in our studio, there's a "seamless" quality to his work that many two-way's don't achieve. Also, many woofs aren't capable of being crossed high, say above 2.5 or 3-kHz. So cross point choices are limited in many cases.

Cheers

Mark.

[markaudio]

Hi Henkjan,
I'd like to take this opportunity to personally thank you for your design efforts for the Alpair series drivers. You've produced some great designs and helped many new Diyers gain pleasure in the making of their build projects. These contributions and your new ideas are welcomed.

Thanks

Mark.