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Discussion Starter · #1 ·
- DVI switching (or preferably HDMI switching)

- the ability to set different xover points for each channel

- software upgradeable (if not also hardware for i/o)


TM
 

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Quote:
Originally posted by anthonymoody


- the ability to set different xover points for each channel



TM
This is one feature that I just don't get. I would think that this could cause more problems then it solves, unless there is a separate sub for each x-over setting.
 

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Quote:
Originally posted by anthonymoody
- DVI switching (or preferably HDMI switching)

- the ability to set different xover points for each channel

- software upgradeable (if not also hardware for i/o)


TM
DVI - switching is great, but why does it have to be in your pre/pro? You may be better off getting a top notch pre without it and a separate DVI video switcher. Also, if your pre/receiver goes to the shop you lose all video switching.


Different crossovers for each channel sounds good but in reality creates more problems than it solves. Read this article:

http://www.hometheaterhifi.com/volum...rs-9-2002.html


Dsmith
 

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I also prefer seperate crossovers for different speakers, and I've actually had this for almost 5 years: Sony TA-E9000ES, then Outlaw 950, and now the Lexicon MC-8.


What problems?


There *are* small issues with phase, but IMO, the benefits far outweigh the negatives.
 

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Quote:
Originally posted by Kevin C Brown


There *are* small issues with phase, but IMO, the benefits far outweigh the negatives.
What are the benefits? The easiest way to not have any over or under emphisis is to have them all set at the same point, and route the low freq to sub(s).
 

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The benefits are that most people's center and surround/rear channels do not have the bass extension their mains do. Hence, you can customize the crossover set pt for each speaker.


(For example, in my case I have the mains at 60 Hz, the center at 80 Hz, and the surrounds/rears at 100 Hz.)


There *are* receivers and pre/pros that do the crossing over incorrectly. I.e., they use the individual crossover freq for the high pass, and then apply a global value to the low passed info to the sub, however, none of the three pre/pros I mentioned above have this problem. They all do it correctly.
 

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Quote:
Originally posted by Kevin C Brown
The benefits are that most people's center and surround/rear channels do not have the bass extension their mains do. Hence, you can customize the crossover set pt for each speaker.


(For example, in my case I have the mains at 60 Hz, the center at 80 Hz, and the surrounds/rears at 100 Hz.)

Just because you can do something does not mean you should do something.
 

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Hey Swampfox- You still have not given any reason whatsoever why I *shouldn't* take advantage of that feature on my pre/pro. :)


And in fact, I specifically have the crossovers set higher than I need to for the surrounds/rears, because rolling off the bass early helps with avoiding a bloated, boxy sound because 3 of the 4 are up against walls.


The bottom line is, if you have a component with individual crossovers, you can set them differently *or* all the same. I.e., you can experiment with what sounds best in your own particular setup. If you have a component with 1 global setting, you can't.


Oh yeah, what I would want from my next pre/pro:


a) individual crossovers :)

b) the ability to set different crossovers for movie sources (DD/DTS) vs 2 ch music (CD). I like to run lower crossovers with music.

c) I would also like to be able to choose my own slopes. 6, 12, 18, or 24 dB. (6/12 for music, 12/24 for movies)

d) Logic 7, THX Ultra2, DPL IIx
 

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My next pre/pro needs to have a maid to keep it dusted, especially in the hard to reach back. And it needs something to support the tons of cables I have plugged into the back.


Oh yeah, that hi-rez digital interface would be nice, but I'm hoping I might eventually get that in my current MC-8.


It also wouldn't hurt if my next pre/pro came with its own bank account.
 

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Oh yeah, un-ending hardware and software upgrades to support new formats. ;)
 

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Quote:
Originally posted by Kevin C Brown
Hey Swampfox- You still have not given any reason whatsoever why I *shouldn't* take advantage of that feature on my pre/pro. :)


c) I would also like to be able to choose my own slopes. 6, 12, 18, or 24 dB. (6/12 for music, 12/24 for movies)
Hi Kevin,


Not that I'm speaking for swampfox, but there are some very good reasons for not using different sub crossovers for mains, center, and rears. Instead of going into details. I'll point you to this article in Secrets of Home Theater and Hi Fi, Here


Pay particular attention to the paragraph named Mixing high and low frequency crossovers in a multi-channel set up


So, the variable slope would definately help, "If" you could change the slopes for each set of speakers individually, which would be pretty complex, I'd imagine. But, as the authors point out you should also have some very expensive measuring equipment, and know how to use it to properly calibrate. Which most of us, including myself don't have.


All this aside, if you like the sound then by all means. I just would not like to deal with it myself. YMMV.


Best Regards,

Patrick
 

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Yes, the infamous Brian Florian article at Secrets. :) Which actually has a lot of incorrect information in it. I sent in a response to a lot of his supposed "issues", but I never got a response.


Point number one: the three pre/pros I mentioned above all do the crossing over correctly, in that the same freq is used for the high pass and low pass for each channel. And in fact, I challenge anyone out there to name just one receiver or pre/pro that has individual crossovers that does the crossing over incorrectly. I know of one, but I'm not going to tell you what it is. :)


Point number two: the phase issues are *not* "monumental". It's very simple really:


Each channel's signal is split with the *correct* HP and LP filter. Before the LP info of each channel is summed into the LFE info to the sub, you time align it. Then you sum.


Easy. The *only* issue is that you will get a phase variance between the the different signals that are crossed over at different frequencies. However, the phase change in this instance is a *continuous* function, such that for example, you get something like this: mains, 60 Hz, phase change = 93 deg; center, 80 Hz, phase change = 101 Hz; surrounds/rears 100 Hz, phase change = 107 Hz, *not* something like 93, -47, +158.


So when you adjust the phase between the sub and speakers, I always pick the mains, because I listen to mostly 2 ch, but you can also pick the center which sort of splits the difference. Bottom line is that if you adjust the phase for *any* of them, the others will not be that far out.


And, let's talk about phase for a minute.


*Most* speakers are not even phase coherent within themselves. (Between the various drivers.) Go read any speaker review in Stereophile if you don't believe this. Phase differences of 45 deg between tweeters and mids, or between mids and woofers are quite common. Only Vandersteen, Dunlavy (RIP), and Thiel, among very few other manufacturers actually sell phase correct, time aligned speakers. On top of that, most subs only have a 0/180 deg switch, which means that you can't get "perfect" phase anyway.


Any other questions? :)


Honestly, I like when this discussion comes up, because it gives a chance to correct some of the misinformation out there.
 

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Kevin,
Quote:
Before the LP info of each channel is summed into the LFE info to the sub, you time align it. Then you sum.
Wouldn't applying time alignment before summing introduce the very phase problems you are trying to avoid? Imagine the low frequencies of 5 or 7 channels, each with an individual delay, being summed together. I think it's better to sum all that bass first, combine the result with LFE content, and then apply one delay (based on how far away your sub is).


Best,

Sanjay
 

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Under the vast majority of situations a single crossover should work as well as, or better than, individual crossovers.

First, in DD tracks, the rears are bass limited. So it really doesn't matter where you cross them. In the minority of sound tracks with bass in the rears, the majority still gets routed to the sub. Ideally, formats that send bass to all speakers, should have identical speakers all the way around.

Second, the presense of low bass in the fronts, in general, does not make the speakers sound better, but may make them sound worse. Having the center with excess bass, clearly muddies the dialog in most cases.

You say that the pre/pro "sums" the bass correctly. Well, it can't. Summing correctly means that the resultant bass is flat, which can only be done with room correction. In general correction is easiest with one sub, one cross-over point.

In your case, my guess is that setting all the speakers to roll off at 80 or 100 Hz to a good sub, will sound as good as or better than the way you have them set up.

I'm really not against the feature, per say, but rather believe it is way over-rated.


Now, wanting to cross over different formats l differently is a whole other can of worms.
 

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"First, in DD tracks, the rears are bass limited. "


No, the rears have the ability to carry full range signals.


"Well, it can't. Summing correctly means that the resultant bass is flat, which can only be done with room correction."


You are confusing two different things. It can sum flat on the line level output. If your room then screws up the resulting sound that has nothing to do with multiple crossovers.


Besides having the abilities to stagger crossovers can be used to advantage to help tame room problems. Overlaps can help fill in suck outs and gaps can tame down peaks.


BTW, on that Florian article notice the little disclaimer at the bottom. That came about from a discussion with Brian pointing out that Lexicon's don't treat bass at all in the manor he thought in the article.


Shawn
 

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Quote:
Originally posted by Kevin C Brown



Honestly, I like when this discussion comes up, because it gives a chance to correct some of the misinformation out there.
Thanks for setting me straight! Though, I still prefer using one crossover setting for my setup. But that's just my preference. :)


Patrick
 

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Discussion Starter · #20 ·
Like I said, the ability to set different x-overs for each channel, *correctly* :)


BTW, the Theta Casablanca and CBII allow for some fairly complex xover settings...you can have a different frequency for each channel, high pass *and* low pass, crossover type *and* slope...again distinct for each channel.


The Theta has some compromises however...IMO a generally 'slow' rate of upgrades/updates to IO, software, etc.


TM


PS - as for why DVI switching at the pre/pro? 1 word - convenience.
 
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