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Posted By: sotwell dual center channels (2x vp150)? - 05/28/09 07:31 PM
I am considering getting 2 vp150s for my dedicated theater. One above and one below the screen. Has anyone done this? Is there much benefit?
Posted By: EFalardeau Re: dual center channels (2x vp150)? - 05/28/09 08:02 PM
I am using that. It anchors the dialogue to the center. The biggest difference for me was multi-channel music where I had a problem with vertically skewed soundstage depending if my center was on top or on the bottom. For HT only, I could have lived without with no regrets. If you get two, make sure they do not "crossfire" as they will interfere with each other. One aiming at your stomach (the bottom one) and the other aiming slightly above your head gives a very good center image.
Posted By: BlueJays1 Re: dual center channels (2x vp150)? - 05/28/09 08:05 PM
Hello sotwell,

I believe JC, one of the Axiom Audio specialists uses dual VP150's in his dedicated home theatre system. They are hooked up to the Axiom A1400-8 amp. I bet he could help you out a lot with any questions you have.
Posted By: sotwell Re: dual center channels (2x vp150)? - 05/28/09 08:38 PM
I have the opportunity to buy 2 used mint vp150 (I currently have m60s)and thought that this may be worth it. I have read on other sites that 2 centers was not a good idea. But I will have a large dedicated HT 22x17x10 with a 136" 2.35x1 screen and thought that with my stadium seating, 2 centers may work well.
Posted By: SirQuack Re: dual center channels (2x vp150)? - 05/28/09 09:15 PM
I'm sure it would work once you get it all setup right, keep in mind your ohm rating for that channel will be around 3ohms if your receiver is ok with that.

I have the same size screen you do, with 2 rows of seating and my single 150 seems totally fine, and the voices appear to come from dead center of the screen, by using a slight tilt upwards of the speaker.
Posted By: Jc Re: dual center channels (2x vp150)? - 05/28/09 10:37 PM
Hi Scotwell,
Dual center speakers is the way to go without hesitation.

The center speaker needs to reproduce between 70 to 80% of the movie soundtracks on its own; it will bebefit from all the help it can get.

Dual center speakers . . . The larger your main speakers are, the more sense it makes . . . The larger your video screen is, the more sense it makes . . . The more rows of listeners you have, the more sense it makes.

Most of the times, your main speakers will have a larger enclosure and more drivers than the center speaker; adding a center speaker makes thing more even . . . One center speaker above and below the screen perfectly locks the sound in the center of the screen where it should be . . . When you have multiple rows of listeners, using a single speaker, the sound will be optimized for only one row or of a lesser quality for all of them.

Connecting them in parallel will lower the Impedance to 3 Ohms but it is a very easy 3 Ohms and a quality receiver or amplifier will power them. I used to power mine with a Newcastle receiver and it never failed even under abuse. Alternately, you could connect them in series which would not lower the Impedance and according to Ian C. who designed the VP150v2 (and all Axiom speakers) it will not affect negatively the sound quality of the VP150v2s.

Now, I’m spoiled, I power each of my VP150v2 with its own A1400-8 channel . . . endless power with frightening dynamics . . . Vive 8 channels !

Using dual center speakers creates a wall of sound and contrary to what you might have read the quality of the sound reproduction does not suffer from any negative effects when properly installed. In fact, you get superior intelligibility at lower volume level.
Posted By: fredk Re: dual center channels (2x vp150)? - 05/28/09 10:45 PM
I'm using dual M2s as centers above and below. It does a great job of centering the dialog, even on a smaller screen.
Posted By: sotwell Re: dual center channels (2x vp150)? - 05/29/09 01:50 PM
JC - could you please provide some more details on connecting them "in parallel" vs "in series"? How would I actually wire under each sceniro and is there a performance advantage on one vs the other? I am planning on using the Denon 3808.

Also, if the centers are an older version (TI) and my m60s are v2, would that be an issue?
Posted By: ClubNeon Re: dual center channels (2x vp150)? - 05/29/09 02:00 PM
Parallel: Two sets of wires running from the + and - of the receiver to each of the posts on each speaker. So they run out as a Y.

Serial: One wire from the + of the receiver runs to the + of one speaker. A wire connects the - of that speaker to the + of the second. Last, the - of the second runs back to the - of the receiver.
Posted By: BlueJays1 Re: dual center channels (2x vp150)? - 05/29/09 02:09 PM
There was a thread a while back, (hopefully someone remembers which one and can post that again) that had a drawing/visual aid on how to connect series and parallel.
Posted By: Ya_basta Re: dual center channels (2x vp150)? - 05/29/09 02:15 PM
Here's a link that I had bookmarked, and it will help you out.
Posted By: Micah Re: dual center channels (2x vp150)? - 05/29/09 03:05 PM
Wow, you can even wire your speakers in series AND in parallel... oi vey!
Posted By: ClubNeon Re: dual center channels (2x vp150)? - 05/29/09 03:36 PM
For fun at lunch in high school one of my friends and I would draw circuit diagrams with resisters in both parallel and series, and then challenge the other to compute the total resistance of the network.
Posted By: Micah Re: dual center channels (2x vp150)? - 05/29/09 03:48 PM
 Originally Posted By: ClubNeon
For fun at lunch in high school one of my friends and I would draw circuit diagrams with resisters in both parallel and series, and then challenge the other to compute the total resistance of the network.



Hold on, did you say 'for fun'...


[Austin Powers Voice] NERD ALERT!!! [/Austin Powers Voice]


Just teasin!
Posted By: Golden Re: dual center channels (2x vp150)? - 05/29/09 03:53 PM
 Originally Posted By: wheelz999
Here's a link that I had bookmarked, and it will help you out.


Thanks for that link, very useful for future reference.
Posted By: MarkSJohnson Re: dual center channels (2x vp150)? - 05/29/09 06:19 PM

Posted By: Jc Re: dual center channels (2x vp150)? - 05/30/09 01:45 PM
 Originally Posted By: sotwell
JC - could you please provide some more details on connecting them "in parallel" vs "in series"? How would I actually wire under each sceniro and is there a performance advantage on one vs the other? I am planning on using the Denon 3808.

Also, if the centers are an older version (TI) and my m60s are v2, would that be an issue?


Scotwell, older VP150 center speaker models with the latest M60 version will provide you with the same benefits; they aree compatible. Your Denon could drive them even if they were connected in parallel which is more demanding because of the lower resistance. A parallel connection is the way which should be normally used.

Mark provided us with a clear connecting sketch of both options; thanks Mark !

Have a superb weekend, All !
Posted By: fredk Re: dual center channels (2x vp150)? - 05/30/09 03:41 PM
 Quote:
Mark provided us with a clear connecting sketch of both options; thanks Mark!


Did he? Cam's link shows a complete loop back to the receiver. Mark's drawing shows the wiring terminated at the second speaker.

Is there a difference between the two or are they the same? Electronically challenged minds want to know...
Posted By: Ya_basta Re: dual center channels (2x vp150)? - 05/30/09 04:00 PM
Fred, the only difference is that mine is clearly better \:\) .
Posted By: fredk Re: dual center channels (2x vp150)? - 05/30/09 07:18 PM
Cam. If we go that route, I think I'll ignore the wiring entirely and move back to the Caregiver thread. Definately better!!
Posted By: ClubNeon Re: dual center channels (2x vp150)? - 05/31/09 01:07 AM
Mark's series is wrong. That's just parallel with the second speaker 180 degrees out of phase.

For it to be a series the current has to flow through one speaker and then the other before returning to the amp. So the two shouldn't share both wires between them.
Posted By: JohnK Re: dual center channels (2x vp150)? - 05/31/09 01:38 AM
Yep. The terminology that the parallel connection "places a higher demand on the amp" could also be questioned as being too simplistic, since a lower impedance makes it easier for the voltage to "push" the current through the speaker.
Posted By: ClubNeon Re: dual center channels (2x vp150)? - 05/31/09 03:00 AM
I agree, that "places a higher demand" is wrong. Maybe "demands a better amplifier", but a lower impedance is not demanding anything, it is actually easing the flow of current.

But there in lies the problem. Think of it this way, a 0 Ohm speaker would actually be a short across the amp's terminals. So the lower the impedance presented to the amp the more current is going to flow, and the more unstable the components through which the electrons are moving will become.

Also an easy way to think about the parallel vs. serial connections would be to picture each speaker as a restriction to the flow. If the feed at the amp is initially divided and allowed to flow through each speaker beside one another; the flow is doubled because the restriction is halved. But if the flow has to go through one speaker and then the next; the flow will be cut in half because there is twice as much restriction.
Posted By: fredk Re: dual center channels (2x vp150)? - 05/31/09 05:14 PM
 Quote:
Mark's series is wrong. That's just parallel with the second speaker 180 degrees out of phase.


Great! So I'm running my centers in parallel with one out of phase. Doh!

On the plus side, Mark, your reputation for being helpful on the boards is untarnished. ;\)
Posted By: CV Re: dual center channels (2x vp150)? - 05/31/09 05:15 PM
Mark Squareroom has been taking his frustration out on us.
Posted By: fredk Re: dual center channels (2x vp150)? - 05/31/09 05:18 PM
\:D

I like his new screen name. Mark, we expect a new avatar by the end of the day.
Posted By: MarkSJohnson Re: dual center channels (2x vp150)? - 06/01/09 12:41 PM
 Originally Posted By: ClubNeon
I agree, that "places a higher demand" is wrong. Maybe "demands a better amplifier", but a lower impedance is not demanding anything, it is actually easing the flow of current.

But there in lies the problem. Think of it this way, a 0 Ohm speaker would actually be a short across the amp's terminals. So the lower the impedance presented to the amp the more current is going to flow, and the more unstable the components through which the electrons are moving will become.

Also an easy way to think about the parallel vs. serial connections would be to picture each speaker as a restriction to the flow. If the feed at the amp is initially divided and allowed to flow through each speaker beside one another; the flow is doubled because the restriction is halved. But if the flow has to go through one speaker and then the next; the flow will be cut in half because there is twice as much restriction.


Now how do I fit all of that on the little graphic??? \:\)
Posted By: MarkSJohnson Re: dual center channels (2x vp150)? - 06/01/09 12:49 PM
 Originally Posted By: CV
Mark Squareroom has been taking his frustration out on us.


Holy crap! I never even thought of that! It's so classic, it's pretty much a cliche!

I can't achieve the same level of success that you guys do, so I can become bitter and start taking it out on all of you! This is -- like -- Marvel Comics -- good.

I can be the one that becomes Evil here.... and we all assumed it would be JP that turned Mad and Evil...

How can a Monday morning be improved? Have a goal!
Posted By: St_PatGuy Re: dual center channels (2x vp150)? - 06/01/09 12:50 PM
\:D
Posted By: pmbuko Re: dual center channels (2x vp150)? - 06/01/09 01:08 PM
Spongemark Squareroom?
Posted By: Murph Re: dual center channels (2x vp150)? - 06/02/09 02:57 PM
 Originally Posted By: pmbuko
Spongemark Squareroom?


Snicker.
Posted By: Micah Re: dual center channels (2x vp150)? - 06/02/09 03:53 PM
Hmmm... this thread almost has me wondering if I should have gone with dual VP100's? This way I could have split them up (one below and one above the screen), and had one extra midrange woofer. And all these advantages would have cost a mere $100 bucks more than the VP150... DOH!!!
Posted By: Adrian Re: dual center channels (2x vp150)? - 06/02/09 09:42 PM
Another symptom of Axiomwaititis....
Posted By: Potatohead Re: dual center channels (2x vp150)? - 06/02/09 09:53 PM
 Originally Posted By: Micah
Hmmm... this thread almost has me wondering if I should have gone with dual VP100's? This way I could have split them up (one below and one above the screen), and had one extra midrange woofer. And all these advantages would have cost a mere $100 bucks more than the VP150... DOH!!!


They won't disperse as well as a VP150 for off axis sound, or sound more than 15' away... According to Axiom tech support anyway.
Posted By: BlueJays1 Re: dual center channels (2x vp150)? - 06/02/09 09:59 PM
 Originally Posted By: Micah
Hmmm... this thread almost has me wondering if I should have gone with dual VP100's? This way I could have split them up (one below and one above the screen), and had one extra midrange woofer. And all these advantages would have cost a mere $100 bucks more than the VP150... DOH!!!


For centre channels the VP150 is the better choice for your setup. Much better power handling that can keep up with the rest of your system and room.
Posted By: ClubNeon Re: dual center channels (2x vp150)? - 06/03/09 01:40 AM
Sounds like you made the right choice with the VP150. So wait a couple months and get a second. \:D Better dispersion left and right, and then a friendly phantom placing the audio up and down.
Posted By: MarkSJohnson Re: dual center channels (2x vp150)? - 06/03/09 10:37 AM
 Originally Posted By: ClubNeon
and then a friendly phantom placing the audio up and down.

Randy?

As the resident expert here, wanna make a comment?
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