where do you cross over your ht setup

First I must say everything im writing here assumes one has proper amplification for each channel in his system. It also assumes sustained SPL levels no greater than what each channel is capable of.

Crossing over at standards designed around large cinema's seating 100's of people simply has no place in HT. Crossing over at 80hz or higher when you have speakers capable of useful output much lower than this is a complete waste. You lose any stereo or surround low bass imaging mixed into the soundtrack and likely overwork your subwoofer. Forget all the THX/Dolby mumbo jumbo right now. Dont let people tell you that you low bass is non-directional. Its complete nonsense for many reasons. Sure, perhaps a 20hz note is near impossible to localize but 30hz and up this isn't completely true. Without getting into a huge discussion regarding low bass I will just offer some advice based on my experience.

Maximize the low bass output of each of your HT channels. This requires a processor that was not lazily designed around cinema standards and allows low enough settings for even full range loudspeakers. In my case I crossover my mains at 25hz, my center at 35hz, and my surrounds at 40hz. This allows each channel to operate to its potential while maintaining the channel integrity of the mix. This also protects the speakers with the processors built in high-slope crossovers by relieving them from bass duties they aren't equipped to handle.

My ideal system is 5 - 7 honest full range channels plus a dedicated LFE sub (or two) in a room designed around the system. This is simply not practical. Another way would be to integrate subwoofers into each channel and run full range. This requires a setup method like Vandersteen recommends with filters to roll off the signal before it gets to the amp (protects the speakers) and a subwoofer that compensates precisely for the filter. Although the results can be excellent, having 6 subwoofers and the wiring/filters needed for this would present spaghetti nightmares in my room.

Where does that leave us? Leaves me smiling. Leaves some of you wishing you had a processor that allows you to maximize the low bass potential of each your HT channels.

Vedric

If you need to EQ a single sub because of room response or poor speaker selection and placement then go for it. You totally destroy the DD or DTS mix in the process.

I can understand crossing over surrounds at 80 - 120 if the surrounds aren't designed for near or on wall operation. In that case the bloated bass could be a problem. I guess the same applies with poor placement and selection for mains. If you cant let the speakers breath like they need to for linear response then cut em off!

Flemke, setting the crossover settings in a HT processor is hard for you? Sorry to hear that. The interface on my processor is quite simple.

I will not submit to specs based on compression horns surrounding a 200 seat cinema where loudness and shock value are the primary criteria. 80 - 120 hz works for cheap cinema speakers. 80 - 120 hz works for the small HT in a box type systems. It's nothing more than an "easy way out" if placement options are limited, or if one doesnt wish to take the time to properly select and setup speakers for the room.

My HT mains are also my 2ch. mains. They are flat to 30hz (IRR) and tail down 9db at 20hz. Why on earth would I want to cut them off at 80hz??? This is crazy THX cinema mumbo jumbo. Hook line and sinker..

You're kidding right? I have no problems with EQ's. Not sure where you gathered that from. I'm also not sure what "old ideas" you think I'm holding on to.

If you can get linear response to 20hz with your mains why cut them off at 80hz? If you can get linear response to 35hz with your surrounds why cut them off at 80hz? Can you answer this in any reasonable way?

You guys are nuts! :)

Eldartford first.. I dont think you have followed what ive said very closely. I do crossover my speakers just not at THX cinema standard 80hz or higher. Its a waste if you have useful linear output below that point.

Kgveteran I can tell you a thousand times I have fairly flat response to 30hz (-2db'ish) with my mains. Im down 4-5db'ish at 25hz. I have a 2-3db peak around 60hz but this is a voicing issue. What a waste to cut them off! I also am most certainly NOT sitting in the middle of a room mode. If you wish snub your nose and call me a liar its no skin off my back. Keep on keeping on and I will as well, enjoying proper placement of 5 channel mixes all the way.

Bye

Eldartford, simple answer. Proper directionality (localization) of low frequency information mixed into the 5 channel soundtrack. Throwing everything to a sub located in a corner ruins the mix. If there is a 70hz buzz in right rear channel I want it to come from the right rear channel!

I would like to add a few responses to exertfluffer. Some of what I said you responded to out of context. No worries and Im not going to troll through what you've said to quote, your posts are huge! :)

I somewhat resent your comments about 2ch. audiophile setup being somehow outdated. Acoustics is acoustics. Building a HT around quality 2ch. setups has produced the finest results in three rooms ive been involved in (one being my own). In fact I believe its the only way for true high performance HT. That is, performance closest to the source (origonal mix). Sure this can be difficult but its not impossible. My point is: people with a quality 2ch setup are already ahead of the game and likely dont need to crossover their mains so damn high!

With a good room, a little work, and proper surround speaker selection you might be suprised at how much lower you can cross your surrounds to! Again, its ALL dependant on SO many factors. However, trying to utilize every last little bit of linear response out of each speaker is worth the effort in my experience. This effort will also teach one much about his own system and acoustics in general.

Dont forget why surround sound is so fun to begin with. Instead of directional imaging taking place more or less within the boundaries of 2 speakers, with surround this directionality can now wrap around us and even hover above our heads. It can be outstanding but every octave cutoff from each channel is sound that no longer contributes properly to this illusion.

I would remind you also that THX standards were NOT designed with HT in mind. These standards were "adapted" to HT as a foolproof way to setup a system. Nothing more, nothing less. Does it work? Sure it does. Is it the best way to setup a HT? Not to these ears.

Drew when you make the switch from 80hz 2nd order to 40hz 4th order you will absolutely notice a difference in directionality of your mains. Any panned image utilizing each channel from 80hz and lower will create a more palpable image. A horse riding in soft soil from R to L for example.

Depending on your previous subwoofer setup you may or may not be able to recognize this right away. If for example you had a pair of subwoofers in each front corner both working off the single LFE channel you would be used to a more frontal diffuse sound in this region. The actual change will be more difficult to locate.

If you were using a single subwoofer operating in a corner the difference will be obvious if your mains are up to the task. You are moving in the right direction providing your room doesnt freak out on you!

Eq'ing a sub properly between mains and surrounds remains a challenge in all but the most perfect rooms/systems but it seems most manufacturers are "getting it". Velodyne's digital drive subs as yet another eq'able example.

If its mixed from the right rear any attempt to reconstruct the signal from the right rear is one more step toward sonic perfection. This cannot disputed.

PS: Im glad that Sean guy somewhat agreed with some of what I've said! I would hate to have one as long winded as him as an enemy! Just kidding Sean! :)

Dont put words in my mouth Eldartford. I haven't recommended any specific crossover point. I mentioned where MY system is crossed at. I have in fact stated its VERY system and room specific several times. I have also stated that preserving as much linear low frequency extention from each channel is critical to hearing the soundtrack AS IT WAS MIXED. What part of "hearing a 70hz buzz from the right-rear actually COME from the right-rear channel" do you not understand?

All of this within reason obviously. If your speakers and amp cant handle 105 - 110db dynamic peaks at XXhz and you often listen at that level then DONT run them that low. If your're sitting in a mode you cant get rid of then by all means cut them off and redirect it all to LFE and work with the sub.

Also what argument "doesn't apply" when running multiple subs? You do understand the difference between discrete channels and multiple speakers hooked up to a single channel correct? It does not matter how many subs you use for the LFE channel its still a single channel with each sub playing the same signal. This is not stereo, nor is it surround, the channels are not discrete. This is a mono channel and it will ONLY image at the acoustical center located somewhere between the boxes depending on where you place them.

There is a TON of discrete and panned directional information mixed into soundtracks below 80hz. Throwing it to LFE for any reason other than system capability or room interaction issues is a complete waste of not only your speakers but also destroys the mix below 80hz.