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The 80Hz crossover setting is the standard set by THX. Although this may seem high it is the best compromise as a good sub will easily handle the rest. I understand your concern for letting the mains do what they can do but this puts more strain on the receivers amp/power supply section and this in turn limits the maximum output the receiver can do for the surrounds.
The mains I have play down to 32Hz and in pure two channel mode they sound great but for movies I dont want that. Remember that even with a crossover setting of 80Hz this does not mean the frequencies below that dont get through it just means that at 80hz the curve will then fall off so blow 50hz there is no output. Does your receiver not have an independent eq for the mains? You could then just roll off the frequencies below 30hz.
 

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Do you have the option on your receiver to send the sub output to main speakers and sub at the same time???? ... my Yamaha RXV 2700 has that option, I'm using JBL Stadiums for the main front, they go down to 35Hz; so what I did is to set them to small (according to manual, it doesn't matter if they're set to small or large when using for sub output), crossover to 80HZ and sub output send to Both (front speakers and Sub) :yes: :yes:
 

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Discussion Starter #23
I've just always followed that rule and I don't think any guidelines would convince me otherwise. If recommendations don't agree then I'll bite my lip about it. I'm sure the crossover slopes built into the AVR also have an influence on how close to the speaker roll-off you can crossover. That is one of the nice things about external active crossovers...you have complete control over these sort of things.
That of course raises a few questions as well...
How much margin is "adequate" to ensure the AVR doesn't hit the slope on the speakers... ?
I can verify by scans, but do speakers (not talking about low end stuff here) typically roll off where the mfrs specify it, or do they give a little "extra"?
 

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Discussion Starter #24
Why not set up your system for no sub at all during music playback? If your mains as you say can go below 40hz, it's unlikely a sub will help much depending on how loud you listen, the type of music you listen to (hip hop/rap will require a sub) and the power of your AVR. I listen to music in stereo (most of the time) with my mains set to large and my subs off. When viewing movies, I go ahead and cut in the subs (I have 2) which are crossed over at 80hz (I use the recommended THX crossover point despite the fact that my mains are easily usable to ~24hz). In most cases, IMHO your speakers will handle 90% of all music no problem, but as others have said; you should try it both ways as simply by crossing over at 60hz or 80hz will take a huge drain off of your AVRs output as well as the bass drivers of your speakers and in all likelihood make your system sound a lot more "open", "detailed" and "smoother".
Just my 2 cents worth...hope it helps!
Cheers,
Konky.
Only real reason here is it's not as convenient to change in the AVR as perhaps some, so I'd rather to pick one setup to use for both modes, especially for the WAF... also, even thought I don't normally listen to the hip hop and rap, I want to be able to perform there when necessary...
 

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Discussion Starter #25
The thing is, and like I said before, a properly set up sub will outperform your mains. A properly set up sub will have EQ and freedom of location that you don't have with your mains. The response from a properly EQ'ed and placed sub will be smoother and have more headroom than your mains. Music or movies, there is no fundamental difference. It's all sound. Movies often put more of an emphasis on extension, where music demand more agility and precision. This is a broad generalization though. 50% of a movie soundtrack is music.*

*Non-scientific guesstimate
THX generally quotes that 70% of a movie soundtrack is dialog...
I'm of the opinion that there IS a difference between movie and music, the sound is different... yes, a perfect system in a perfect room will sound superb for both, but since that isn't an option, there are tradeoffs... in music, I much prefer the sound of 2 good full range speakers to 2 monitors backed by a sub with an 80Hz crossover... in movies, as long as it's not above 80Hz, I believe the exact crossover point to be less of an issue... in music, the more extension you can get out of the stereo pair the better, assuming of course, you don't sacrifice flatness, and have the ability to properly place and aim them...
Lastly, in some regards the full range allows more placement options than the single sub, to the extent that they're two separate sources, although there can be phase issues, and they have to be placed somewhere that provides adequate imaging, careful placement of 2 sources can help combat modes better than 1 source.
Of course, if you sacrifice response, all bets are off...
 

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Discussion Starter #26
Well, I don't have an arguement with the Dolby link because I'm certainly not a pro. I'm just a novice builder but have built a system that everyone who has listened to it says it's the finest sounding they have ever heard, bar none. I'm just providing you with the settings that I've found to give me the most, and best, sound I can get with my system. I usually listen to music and some concerts in two channel only because the mains are so good.

My Rotel has the sub output and that's the one I use. I am to assume that is the LFE rca jack as well.
Like I said, I was getting semantic, and I don't know the Rotel, but most amps will have a sub output, but not an LFE output... they're different.

As far as bass guitar reproduction,
good luck with the Reckhorn... as for bass guitar, and the other instruments, the question was really what frequencies the lowest fundamentals run down to...
 

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The 80Hz crossover setting is the standard set by THX. Although this may seem high it is the best compromise as a good sub will easily handle the rest. I understand your concern for letting the mains do what they can do but this puts more strain on the receivers amp/power supply section and this in turn limits the maximum output the receiver can do for the surrounds.
The mains I have play down to 32Hz and in pure two channel mode they sound great but for movies I dont want that. Remember that even with a crossover setting of 80Hz this does not mean the frequencies below that dont get through it just means that at 80hz the curve will then fall off so blow 50hz there is no output. Does your receiver not have an independent eq for the mains? You could then just roll off the frequencies below 30hz.
I've played with the 80hz setting and it affects the sound quality of my mains. I've paralleled two Lambda TD12s drivers in each main, as well as the Scan Speaks I have for my mids. The mains aren't as detailed with the higher setting, so I'm very happy with the 60hz. The two Lambdas in parallel can reproduce the 60 to 80hz much better than the sub. As far as what THX recommends, it is just that, a recommendation. The end user tweaks their system for their optimal performance and pleasure.

I don't have a crossover adjustment for the mains.

My Rotel processor/amp is a very high current amplifier and can easily power my mains, center, and two surrounds. I have a separate amplifier for my two center backs.

This is not to be taken as an arguement, but rather a discussion. That's why we have our forums to share information with each other.

Mike
 

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This is not to be taken as an arguement, but rather a discussion. That's why we have our forums to share information with each other.

Mike
Sorry Mike, no argument was intended here I was just stating what I know and what usually works.
At this moment I have my mains set for Full with no crossover as my sub is a little week and I have a separate amp driving them but this will change once I get my SVS PB13 Ultra.
 

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I have very capable fronts. They can easily handle 40Hz at reference, and lower down if I don't go mental. Still, they sound so much sweeter when I cross them over at 80Hz. A properly set up subwoofer will "always" outperform a fullrange speaker down low. You are not using your system to it's full potential if you DON'T cross them over at 80Hz.
You are wrong plain and simple, if your system sounds better crossed over at 80HZ maybe that works for you but in my system it isnt the case, with my power reserves, speakers that go down to 16Hz.... bi-amps with outboard active crossover, 80Hz isnt the way to go. What works in your system does not become an absolute rule.
 

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Sorry Mike, no argument was intended here I was just stating what I know and what usually works.
At this moment I have my mains set for Full with no crossover as my sub is a little week and I have a separate amp driving them but this will change once I get my SVS PB13 Ultra.
I understand your point and is well taken.

You will love your SVS subs. I've heard a lot of good things about them..

I broke all the rules by putting two RLP 15s in a 5 cu ft box with 4 passive radiators each, but the results are fantastic. I have a lot of rebuilds, (total of 5 for the sub alone) starting 3 or 4 years ago to achieve the sound I am most happy with.....we call this stuff DIY and we are supposed to enjoy our projects.:rolleyes:

BTW....The Lambda line of woofers and subwoofers were custom designed, machined, and built in Florida and as far as I could tell, was one of the highest sought after driver in the world. Nick didn't charge enough for them and eventually sold out. I was negotiating purchasing the business and inventory from him but am lacking in the audio technical department to make a success with their continued production.
 

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You are wrong plain and simple, if your system sounds better crossed over at 80HZ maybe that works for you but in my system it isnt the case, with my power reserves, speakers that go down to 16Hz.... bi-amps with outboard active crossover, 80Hz isnt the way to go. What works in your system does not become an absolute rule.
This is exactly why I put the 'always' in quotes. Not many have mains that will play comfortably in the lower ranges. I have no signs of strain when playing low stuff on them, they have no problem handling music on their own, but even so they are sweeter and cleaner up high with the lower end crossed off. I would think that about most systems really, regardless of quality. I have good headroom, a bi-amped setup and not a very big room to fill.
 

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sorry I didnt see quotes but all the same I think in general you are correct but for those of us with true full range and various other equipment that is not really the norm the 80hz rule doesnt apply. I didnt want to start a debate just adding that there are almost always exceptions to even the most universally believed rules of thumb, if my goal wasnt a music first system I believe I would probably be firmly in the 80hz camp with most others......cheers
 

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Wasn't that 80hz cross over thing brought out/setup by THX anyway?

IMO, it really has no basis when it comes to music systems unless your system can not handle frequencies below that with authority. Speakers should be set up as dictated by the capabilities of each speaker or system and the way each individual likes, as that is all that really matters.
 

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This one has taken on a mind of it's own. Let's summarize. 80Hz crossover is a good rule of thumb for "movie centric" systems but is still largely determined by personal taste and system capability. If you don't have the time or necessary resources to test your system out, set it and forget it. If you want to play around with different frequencies...by all means. For "music centric systems", many prefer to leave full range speakers handle the bulk of the low end material but will probably need to crossover to a sub and some level. Again...do some testing.

Now...as for glaufman's original question... Have we sufficiently turned you around enough so that you have no idea where the donkey's tail needs to go?
 

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Discussion Starter #35
The 80Hz crossover setting is the standard set by THX. Although this may seem high it is the best compromise as a good sub will easily handle the rest.
Although I believe in THX, this is one area where I differ from their opinion... I prefer a lower crossover...

I understand your concern for letting the mains do what they can do but this puts more strain on the receivers amp/power supply section and this in turn limits the maximum output the receiver can do for the surrounds.
I don't believe my receiver is being strained, and I certainly have plenty of output room for the surrounds...

Does your receiver not have an independent eq for the mains? You could then just roll off the frequencies below 30hz.
It does, but the characteristic is limited to the point where I don't think this is practical... it's only 3 band, the bass and treble can only adjust levels and cutoffs, (high for the bass, low for the treble) and level and center for the mid, without an adjustment for Q or BW...
 

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Discussion Starter #36
Do you have the option on your receiver to send the sub output to main speakers and sub at the same time???? ... my Yamaha RXV 2700 has that option, I'm using JBL Stadiums for the main front, they go down to 35Hz; so what I did is to set them to small (according to manual, it doesn't matter if they're set to small or large when using for sub output), crossover to 80HZ and sub output send to Both (front speakers and Sub) :yes: :yes:
I don't think I understand... if the mains are set to 80Hz, shouldn't anything below that be sent only to the sub? You can set the mains to 80 and still get the sub output sent to the mains? that doesn't seem to make sense...
 

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I don't think I understand... if the mains are set to 80Hz, shouldn't anything below that be sent only to the sub? You can set the mains to 80 and still get the sub output sent to the mains? that doesn't seem to make sense...
That does seem somewhat counter intuitive, but I think what happens is that both the sub and mains get material below the crossover and LFE. In other words, the mains get full spectrum and LFE. The sub gets low frequency material from the mains and LFE. You'd better have some serious capability on the mains to handle that.
 

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I run full plus sub in my Rotel, it is useful when you have full range fronts for extra depth in the presentaion but center and all surrounds follow what ever cross over you set. If my speakers couldnt handle bas as low as they do (Iam down -10db at 16Hz) I wouldnt use this feature as it could be a woofer killer.
 

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Discussion Starter #39
Now...as for glaufman's original question... Have we sufficiently turned you around enough so that you have no idea where the donkey's tail needs to go?
Actually, I think I have a direection as to how I'll probably go, at least to start, which'll be to use the 60Hz crossover the rcvr allows, and see how it sounds, since noone argued (at least not that I've read yet) with the assertion of staying away from the speaker's cutoff in any case... I'd still like to hear opinions on that, and answers to some of the questions that raised in my mind, basically...
How much room is adequate to keep the crossover above the mains' cutoff?
The other questions it raised, such as is the receiver supposed to do this itself, I can answer empirically, once the wife goes away for a few days...

The only question left really will be whether I make sure to get a sub with high level in/outs, so I can eventually use its crossover to power the mains in case I decide I need ot listen to that to see if it's better, and what people think, if the crossover in these subs has characteristics sufficiently flat etc to do this effectively, or if it's a gimmick to stay away from...
 

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Discussion Starter #40
That does seem somewhat counter intuitive, but I think what happens is that both the sub and mains get material below the crossover and LFE. In other words, the mains get full spectrum and LFE. The sub gets low frequency material from the mains and LFE. You'd better have some serious capability on the mains to handle that.
I think that depends on how the receiver is designed, and how you've set it up...
Theoretically, the receiver is under no obligation to send LFE to the sub... if you tell the receiver your mains are "large," that implies full range, in which case it can very well send the entire LFE to the mains and nothing to the sub... (according to Dolby) ... if all the sats are set to small with a crossover, then the rcvr should transistion via opposing rolloffs from sats to sub at that rolloff... not that the mains shouldn't get anything below that freq, they have to in order to make the transition smooth, but the signal they're given should rolloff... another question becomes at what slop do they rolloff? 1st order, 2nd order, etc... (6 db, 12 db per octave, 20, 40 db per decade?) I plan to run some tests on my AVR to see what it actually does... I'll post the results if anyone's interested, but due to other projects it may be a while before I get around to it...
 
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