[gprro]

Hi Danny,

Was talking on av123 forum about using X-mtm's vs. X-cs as the mains in a theater set up with subs. Better to use the mtm's full range or crossed over, or the cs's crossed over? Don't know if it really matters when using huge theater subs. Although I think I like the mid and upper bass from the cs a little better?

For blending with subs, is it better to use the natural roll off of the sealed cs's combined with a crossover rather than the mtm's relatively flat response at an 80hz crossover point. I remember George Short from North Creek talking about blending and phasing with subs, but I don't know if it makes a huge difference with theater set ups.

[Danny Richie]

You'll get your best integration the lower that the sub can be crossed over to the mains. I'd go MTM's and allow them their natural roll off.

[klh]

Are you saying in this situation a sealed MTM is the best choice given it's sensitivity is a little higher and should roll of a little lower (than a sealed MT)? Or, are you saying a ported MTM is even better since the F3 is even lower? Do you think it matters that the roll off on a ported speaker below the tuned frequency is steeper than if the box was sealed? Or, put differently, do you value the extended range but steeper roll off of a ported MTM over the lesser range but flatter roll off of a sealed MTM when the low end is supported by a true subwoofer?

[gprro]

Hi klh,
didn't mean to cause confusion, but I was talking about the av123 X-series MTM vs. CS. Basically the same speaker, but the MTM is large ported with an F3 around 40hz and the CS is the same driver setup but in smaller sealed box with F3 around 65-70hz I think. Similar situation to the GR A/V-3 vs. A/V-3S.


I guess it's a little tricky, sealer or ported and crossed over or not. If I were planning on crossing over the fronts at 80 hz though (trying to squeeze the best dynamics out of a receiver), would it be better to go with mtm's or cs's or not matter?

Ideally I would have a main speaker and amps capable of huge volume and dynamics down to 40ish and then the massive sub set up for down to 10hz or so, but for now I'm limited with a decent Marantz  8400 receiver and the X-series speakers (Big subs though). I may move the OB-7s into theater duty eventually when I get the LS-9's  .

[Danny Richie]

Are you saying in this situation a sealed MTM is the best choice given it's sensitivity is a little higher and should roll of a little lower (than a sealed MT)? Or, are you saying a ported MTM is even better since the F3 is even lower?

I am saying that the lower the crossover point that you cross to the sub the better the integration.

Do you think it matters that the roll off on a ported speaker below the tuned frequency is steeper than if the box was sealed?

Sure. It is better in most applications. Keep in mind that you need to match the roll off of the subs in the upper ranges. If the sub has a 24db per octave crossover built in on it then you wouldn't want to match it to the natural roll off of a sealed speaker or the slopes would not match.

Or, put differently, do you value the extended range but steeper roll off of a ported MTM over the lesser range but flatter roll off of a sealed MTM when the low end is supported by a true subwoofer?

A true sub-woofer? If using a sealed box then the crossover for the sub may integrate better using a 12db per octave slope and the sub or subs would need to be placed in closer proximity to the main speakers.

[klh]

GPRRO... sorry for taking this off on a tangent. I've decided to make it a PM. Good luck with your purchase!

[Danny Richie]

Of course this is all theory... in room testing and measurements (not to mention good ol' listening) would determine the best slope.

You nailed it right there. Theory is one thing but room gains and cancellations are pretty rough in those low ranges.

[gprro]

No problem, I can get a little confused about crossing subs with mains. Thats kind of what I was getting at. Gets even more confusing when you stack plate amps with crossovers  on top of the crossover in a receiver. And more confusing when I can't find published crossover slopes for my receiver. Now my brain is twisted 

So in my situation, if I'm trying to squeeze the most potential power out of my receiver by crossing the mains at 80 hz (lowest available ) would the MTM or CS be a better main, or not matter? I guess that can change if I run the mains full range though.

There should be a chart maybe for proper sub and speaker integration. I know for my Ob-7's i was thinking that a plate amp with a 12bd/octave slope would probably match the natural roll off of the sealed 130x's best. I guess sub position also comes into play, and thats when a good  phase control comes in handy.

Danny, any thoughts on George Shorts method of running subs and sats. I was considering something like this for the ob-7's if it would  be better (specially if I'm running tubes). He likes to run a series cap on the rca driving the amp for the sealed satellites to make a third order slope, and then runs the sub with a third or forth order slope. Only advantage i see is removing stress from the amp driving the satellites, or does this help blend them better.

Sorry if these are headache questions. Always been curios about them though. Thanks

[klh]

There should be a chart maybe for proper sub and speaker integration. I know for my Ob-7's i was thinking that a plate amp with a 12bd/octave slope would probably match the natural roll off of the sealed 130x's best. I guess sub position also comes into play, and thats when a good  phase control comes in handy.

I like this option, but you'll need to send your sub and OB-7s equal full range signals. Right? Is your receiver capable of doing that? The OB-7s naturally fall off at a 12dB slope since they are sealed, and your sub would have a low pass 12dB filter that could be adjusted up and down until it complements the fall off of the OB-7s. I suppose the two other factors at play are phase issues (as you mentioned) and room nodes (particularly since the way the nodes are affected by the subwoofer's location will likely differ from the the way the nodes are afected by the OB-7's location. Yikes!

[gprro]

Ob-7s are in a separate system with jolida jd1000 tube integrated with a sub out, maybe switching to separates soon.
I'm making everything a little confusing I think  sorry. Actually the ob-7s aren't even finished, and I've been moving various speakers in the 2 channel set up. I was just thinking out loud while i was on the subject of blending various sub set ups. When I really try to get the 2 channel system dialed in I'm going to have to do some room treatments for bass and other things. Actually I've really been watching the servo set ups. They look awesome. I'd do dual 12's on each side I think 

Right now, I'm really trying to decide if I want to order new X-cs encores, or wait for the upgrade tweeter and parts to make my mtm's the current "encore" models. Trying to figure out which would be better for my current theater set up.

[Danny Richie]

So in my situation, if I'm trying to squeeze the most potential power out of my receiver by crossing the mains at 80 hz (lowest available ) would the MTM or CS be a better main, or not matter?

I'd go for the ported version myself even if you are pulling the lows off of it. Plus, you won't need to buy stands.  

I was considering something like this for the ob-7's if it would  be better (specially if I'm running tubes). He likes to run a series cap on the rca driving the amp for the sealed satellites to make a third order slope, and then runs the sub with a third or forth order slope. Only advantage i see is removing stress from the amp driving the satellites, or does this help blend them better.

That is good and/or bad.

The good is that it does remove stress from the amp and it can help the sub blend with the mains depending on everything else. It is a really good idea for small mini-monitors as it removes some of the mechanical limitations from the speakers and limits them more by thermal limitations only. This can really keep them from getting beat up by low notes that are heavy.

The bad part is that the quality of the cap really matters as all of the signal that your amp receives passes through that cap.

[Danny Richie]

Right now, I'm really trying to decide if I want to order new X-cs encores, or wait for the upgrade tweeter and parts to make my mtm's the current "encore" models. Trying to figure out which would be better for my current theater set up.

Well, one is available right now. I am not sure when or if the upgrade will be available.

[gprro]

Good point on the cap, I think with the ob7's I should just try to go with a big amp, something that could handle the Ls9's too maybe. The Jolida I have is 100W/channel of el34's, but I'm going to try kt77's. I have run out of power on the MTM's with this amp, but it was with Tool at crazy volume in a large space.

I got an email from Sean the other day saying the tweeters were supposed to be done last week, but hasn't heard from peerless yet. Same old, same old I think they are still a go. I'll make a choice in the next couple days. I was going to sell the mtm's to fund the cs's. The encores are a good price right now though, and I don't have 7.1 right now . My place is starting to look like a speaker manufactures.

Thanks

[Loftprojection]

Hello Danny, sorry if I go a little sideways here but if I relate this conversation to the Neo-1X vs Neo-2X kits, it looks to me like building the Neo-1X will provide a better platform to integrate it with a sub versus the Neo-2X that don't go as low?  Or am I completely confused?  By the way you finally never told us if you preferred the 1X or the 2X in your setup? 

Thanks.

[Danny Richie]

Neo-1X vs Neo-2X kits, it looks to me like building the Neo-1X will provide a better platform to integrate it with a sub versus the Neo-2X that don't go as low?

The Neo-1X might be a little easier to integrate in most situations. In my room both were pretty easy.

I found that the Direct Servo sub is really easy to integrate. That plate amp has everything on it one would need and it makes it really easy to dial it in to match anything.

By the way you finally never told us if you preferred the 1X or the 2X in your setup?

I never really decided. They were much more alike than different.