[azryan]

Any chance of seeing dual Neo 8's in a 45 degree surround cabinet w/ maybe top and bottom mounted woofers (either yours or the CSS ones in the Alphas?).

Would make a great option for a set of main Alphas in a HT room.

Also maybe a monopole version for a monitor style surround too and possible center chan. for those who want one (not me though).

That Neo 10 ever come out either? Been a while since that was first mentioned.

Do you think it'll have that same peak on the top as the Neo 8? And if not... wouldn't is comb too much if used in a line unlike the Neo 8 who's peak you take advantage of to counter a natural combing on the top half octave?

Sorry... too many questions 'eh?

Oh well... gotta kick this forum up a bit. Dust's been settlin' (MDF dust I assume). hehe

[Danny Richie]

Any chance of seeing dual Neo 8's in a 45 degree surround cabinet w/ maybe top and bottom mounted woofers (either yours or the CSS ones in the Alphas?).

Only if you want some and you want me to build you a pair.

Also maybe a monopole version for a monitor style surround too and possible center chan. for those who want one (not me though).

Only if someone wants them. Thus far I have had few ask for them. Most use the Alpha's for high end two channel applications.

That Neo 10 ever come out either? Been a while since that was first mentioned.

It now looks like BG may use that one themselves exclusively and not offer it to other companies.

Do you think it'll have that same peak on the top as the Neo 8?

I have seen no data on it yet.

Sorry... too many questions 'eh?

That's okay. Let me give you one.

Want to try the new bass management system on your Alpha's?

Did you mount your crossover internally or externally?

[azryan]

Thanks for the answers.

I was thinking about Neo 8 dipoles surrounds, but not looking to pay for custom work to get that. Was hoping maybe you'd make a kit. Oh well. heh

By your description of that new bass system it seemed like-

1) having a large room I don't need a diff. inductor than the one you sent me, unlike people w/ smaller rooms?

2) I didn't much like the idea of adding more stuff to a x-over. And resistors on a switch didn't seem like I'd want that in the signal?

One of the reasons I like the Alpha design better than a certain 'other' line of planar based speakers that have a ton of x-over parts in their 'we need some bracing in here!' cabinets. hehe

edit- I mounted the x-over internally. I've got external x-overs on my Newform 645's (my current 'overkill' surround speakers) and my wife doesn't dig it. hehe

Did you change the x-o in your Alphas to the new system you worked up (as our rooms are about the same size)?

Maybe I didn't understand what effect it'll have?

I don't feel like I have overly pronounced bass at all -'cept while watching that damn Finding Nemo! Nearly popped my dual Tempest subs! Glad I had the Alphas on 'small' when I watched it! hehe

The Alphas can handle some evil bass, but some stuff is just insane! hehe

Hey... what is are the ports tuned to?

I think you said you made the cabinet too big on purpose and used the ports to pull down the woofers? Something a bit diff. that just a typical port tuning?
It's true right that below the tuning drivers don't have the control that they do above the tuning -as if they're in open air?

I'm not totally sure what I'm saying, but I think I'm close?

Like how I bottomed out my dual 12" Shiva subs on crazy stuff like U-571 and the THX screen on Star Wars PTM not because too muhc power went too them, but because there was so much content below my 20Hz port tuning?

[Danny Richie]

1) having a large room I don't need a diff. inductor than the one you sent me, unlike people w/ smaller rooms?

The bass management system does not change the size of your main inductor or anything else about your crossover.

2) I didn't much like the idea of adding more stuff to a x-over. And resistors on a switch didn't seem like I'd want that in the signal?

Actually it does not add anything directly in the signal path. It goes in the shunt path and looks like this...


+----------------------------------+
                     
           large value inductor
                     
                resistive load
                     
- --------------------------------- -

The resistor value can be adjusted to allow more or less to be by-passed through the shunt inductor.

I am putting a switch on mine that will allow resistive load adjustments of 33 ohms, 27 ohms, 20 ohms, and 16 ohms.

See measured impedance curves of the effect of this circuit:

http://www.gr-research.com/AlphaLS/measurements.htm

Did you change the x-o in your Alphas to the new system you worked up (as our rooms are about the same size)?

My Alpha's do use the new network design and the bass management system.

When measuring the room response of one speaker setting in the middle of my room, I got a smooth response with little to no room gain.

When I positioned them to the idea listening position about 5' from the rear wall and  3 or 4 feet from the side walls, I got some room gain in the range below 250Hz. Mostly in the 100 to 125Hz range.

When engaging the bass management system lower vocals sound much clearer and balanced.

Hey... what is are the ports tuned to?

See impedance plots. Tuning is at 45Hz.

I think you said you made the cabinet too big on purpose and used the ports to pull down the woofers?

No. The enclosure was made larger than optimal to extend the bottom end which also brought the output down about 3db.

I makes the response look a little like this:

This is not an image of an Alpha LS response. It is just an example.

With the Alpha LS the response drops down about 3db (not 6db) and extends a lower than it would if it were in an optimal ported enclosure.

Then the network becomes active at about 80 to 90Hz and effectively folds the response over making it level with the bottom end. The network pulls 3db worth of output away from it and allows it to equal the output of the Neo 8's.

What was the F6 is now the F3.

Plus, using woofers in an array actually increases the low end extension by a factor based on the length of the array.

With the Alpha LS about 8db more bottom end extension is present than what you would get from a single driver.

How's that?[/list:u]

[azryan]

Ahh... I see.

Uh... well... kinda. hehe

So what's a switch look like/cost w/ the resistors?

Does the added resistors go between the inductor like the 12.5 Ohm I've got there now? Or is that diff.?

I just did what you said to do. Didn't really understand 'what' I was doing! hehe... but that was enough to build these.

Not sure I'd like to open up the speakers again... but maybe.

What setting do you use in your room? I'd think you'd use only one setting right? Whatever measures best?

Thanks for the info. That did sound like a cool thing for new Alpha builders, but thought it might not be for me since I'm already done... but maybe I'd try it?

[Danny Richie]

So what's a switch look like/cost w/ the resistors?

I used a pretty nice switch with Silver coated contacts. Bundles of Mills resistors used total $124.80 retail. It uses lots of resistors.

Does the added resistors go between the inductor like the 12.5 Ohm I've got there now? Or is that diff.?

No.

The main circuit for the woofer uses a resistor that by-passes the inductor. In other words the ends of the resistor is connected to the ends of the inductor.

In the bass management system the are in line, one connected to the other end to end in a line. Then a switch is added in between so that different resistor values can be selected.

What setting do you use in your room? I'd think you'd use only one setting right? Whatever measures best?

For most music I like it with 20 ohms of resistance in line with it. It's nice to be able to change it though when I through on some hard rock.

You could do it pretty cheaply if you wanted.

Just run the leads out the lower port and play with the values (resistors) until you like the way it sounds. Then mount the chosen value and inductor internally when you are through tweaking it. No switches needed unless you want to change it on the fly.

[jonwb]

I used a pretty nice switch with Silver coated contacts. Bundles of Mills resistors used total $124.80 retail. It uses lots of resistors.

Since this bass management circuit is not in the signal path, do you really need to use a "fancy" switch?  I'm assuming the switch is what drives the cost up...

Jon

[azryan]

Jon,

The switch doesn't seem to be to switch the bass mang. curcuit in and out of the path. The bass mang. circuit will always be in the signal path (if I understand it).

The switch is to adjust how much resistor you want on the path to fit your room and/or music you're playing.

You wouldn't need the switch if you were sure exactly how much resist. you wanted, but that might change if you moved the speakers around or to a diff. room/home or diff. music gave you reason to adjust it, or if you wanted to sell them and someone else would want to adjust from what you had.

Personally I'd like to add it, but I think I'm not gonna be able to get into my speakers to do this. I would have done it for sure while I was building mine.

I'm happy the way it is, but maybe dig. eq systems might let me do this type of adjustment. We'll see.