PDA

View Full Version : question on setup of 2445J-horn, woofer, HF



lgvenable
10-31-2010, 02:30 PM
If the attachment is a 2360 plus throat plus 2446, combine with a 2404 and a 2206H, do I need to align the voice coils to get the correct transmission of sound so that all the sound from each driver hits you at the same time? I hacked in a line to approximate the front of the voice coil, but how should each driver line up? Do I use time alignment with a driverack 260?


Audiohack, how do you align your LF's with the 2445/2446 2360 horn - HF configuration?

why is it Google can turn this up, but forum search cant?

http://www.audioheritage.org/vbulletin/showthread.php?5079-Time-Alignment&daysprune=-1

jerv
10-31-2010, 03:05 PM
Hi, lgvenable.

I have a setup much like yours (only difference I use twin 2226's instead of the 2206 - and the 2445 with 2450SL aquaplased dia instead of the 2446).

With the dbx, I delay the 2226's and the 2404 according to the relative distances between the voicecoils, compared to the 2445. In my setup, this corresponds to about 95 cm.

Not through with measuring and tweaking, though.

Good luck with your setup, and keep us posted!

48259

lgvenable
10-31-2010, 06:54 PM
95 cm seems to work out to 0.165 sec, which seems like a lot. So you're using a 165 ms delay via the dBX DR260 for the 2206's?

So essentially your 2360-throat-compression driver sets about 95 cm from the plane of the woofer-2404 voice coils?
see my attached diagram.
BTW the 2360's-2446 came out of a set of the same speaker you have (4675cf). Interesting that you're using a 2450SL aquaplased diaphragm

My 2360's once were part of a set of 4675's like yours; just newer.
see my excel this is how yours is aligned?

1audiohack
11-01-2010, 12:22 AM
Hi;

I would definitely align the front edges for a single plane baffle since you have the ability to add signal delay as needed to the 2206 and 2404 with your DBX 260. I fully believe this results in a far smoother room response and much wider listenable area.

I'm away so this is shooting from the hip, the 2360
is 34-36 inches from diaphragm to mouth end? That's
about 2.5 mSec (0.0025 seconds) from source to mouth right? You won't need all that signal delay added to the 2206's signal as it has some group delay of it's own.

To get from here to there I use the impulse function in TEF to get close and then start picking at it looking at phase.

I didn't use a 2206 under a 2360, but JeffW and I are working on a 2206 project that I can easily plop a 2360 on top and get the exact alignment numbers. Do you have a crossover frequency and alignment picked out yet?

jerv
11-01-2010, 02:05 AM
Yes - my setup is like your drawing. The 2445 voicecoil is about 95 cm to the back, compared with the baffle plane.

This corresponds to a delay of about 2.8 ms.

Use this value for a starting point when determining the exact value. The actual crossover frequency and the intended filter slopes also have some influence on this.