help me resolve these 6.1 setup questions

Discussion in 'Home Theater Projects' started by CodyL, May 6, 2003.

  1. CodyL

    CodyL Extra

    Jul 23, 2002
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    The wife is now on board to complete the media room (I had to give up front projection for 65" RPTV). It is essentially an empty 17X22 room with 9' ceiling over the garage that I can do anything I want to. As for audio, we went to tweeter's and they had the Diana Krall DVD playing on "$20,000 speakers" (don't know or care what they were - goofy looking things though with a metal screen extending 4 feet over the cabinets, if that gives any of you any idea what they were). Now, wife is on board to getting best sound we can afford (meaning under $2500 for speakers and receiver), and I have skills and tools for most woodworking jobs, so I'm DIY bound.

    We want the absolute best clarity possible with tight bass and about 50% music, 50% home theater - nothing at reference volumes but would like it to be able to get plenty loud for movies and as low as possible without compromising music clarity. Here's the tentative plan: I have shard emails with Dannie Richie and he is about three hours from me, so I am going AV1+ LFC and rear center; and AV1 surround. Tempest sub with PE250 amp, probably in a sealed configuaration.

    Last year, Danny wrote the following post:
    "For over all best sound quality and integration without a doubt would be to keep the electronic crossover out of the signal path to your A/V-1's.

    Let them play full range to their -3db down point of 55Hz. After all they do have a natural roll off rate greater than 22db per octave below 55Hz.

    Then let your sub cover the bottom end and adjusting its crossover setting in the 45Hz to 50Hz range.

    For one, crossing a sub-woofer over at frequencies in the 100Hz range, or higher, the sub woofer can be very directional. Meaning you will clearly hear the sound of the sub-woofer emanating from the sub-woofer box itself.

    Setting the sub-woofer setting at lower frequencies will elevate this problem.

    Secondly, allowing the sub-woofer to play higher frequencies will make it very placement sensitive.

    Higher frequencies mean shorter wavelengths. Where it is placed in relation to the main speakers will determine weather they will integrate without causing peaks and dips in the response.

    Keep in mind the phasing problems this presents. This means time arrival problems. You will wind up causing a dip or peak in the range just above or just below the crossing point.

    I recommend any instance where a sub has to play above 80Hz that a pair is needed, and one should be used in close proximity to each speaker.

    Also, the ability of a 15 inch woofer (even for one as good as a Tempest) is no comparison to a good 5.25" inch woofer like the GR-130 in reproducing fast, accurate detail and resolution in the 60Hz and up range. The larger woofer will have way to much stored energy and inertia from playing the lower frequency ranges to do any justice to covering higher frequencies."

    From what I read on the board, I should turn the sub crossover off or all the way up and let the receiver crossover do the work. Makes sense, except most receivers in my price range have the lowest crossover setting at 80Hz. Should I invest in a receiver that will go below 80Hz (Denon 2803 will do 40, 60, 80, 100 and 120)? To maximize the speakers per Danny's post, I need to limit the frequency below 80Hz. Can this be accomplished with a receiver with an 80Hz crossover (the Denon 2802, for example)?

    Finally, as to sub design, I will likely try two or three boxes to see what sounds best since MDF is cheap and I have plenty of tools, but are there any suggestions of a couple to try to accomplish what I am looking for? What measurement tools do I need to truly evaluate the boxes I build?

    Thanks for all of your suggestions past/present/future!
  2. TimForman

    TimForman Supporting Actor

    Dec 4, 2002
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    I think your plan has a great deal of merit and will probably sound great. It's hard to judge exactly how it will sound in your room as all rooms are different in the way they reinforce and subdue frequencies. I'd recommend getting an SPL meter and some test tones. Good receivers will give you an assortment of crossover points. A couple hours of testing should give you the info you need. Personally, I'm using Adire KIT 281's which have good output to 45 Hz but my room kills 55 Hz. To compensate I crossover at 80Hz plus use a BFD. I also have a peak at 70 Hz. The BFD was a tremendous help.
  3. Owen Bartley

    Owen Bartley Second Unit

    Nov 11, 2002
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    Since I seem to have some similar equipment I'll throw in my opinion here... I have a 2802 and am using the 80Hz crossover point for my 210L vented Tempest. Now, keep in mind I'm using it with some Cerwin Vega VS120's (which also pump out a good deal of bass), but with the sub in the corner off to the left it is tough to localize unless you actually look at the big black box. With some of the upper bass stuff the left stage is a bit heavier, but its not enough to be distracting during a regular movie.

    For music on the other hand... you might want to consider building 2 smaller Tempests, one for each side. I guess if I had the means I would prefer to cross over at around 60Hz, but I wouldn't go out and buy a new receiver just for that reason (especially the newer version of my already kick-ass one [​IMG] ).

    Hope this helped some.

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