Mains for low end, or sub?

Discussion in 'Speakers & Subwoofers' started by Scott_Mac, Jun 24, 2005.

  1. Scott_Mac

    Scott_Mac Auditioning

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    I'm in the process of building a new theatre room in my home. I plan to use a pair of Cerwin Vega D9's as the mains, which are HUGE with lots of bass. Should I just forgo getting a subwoofer and use the D9's for the bass, or get a sub, in which case the D9's won't be living up to their potential. It's a large room (20x40ft) and I'm sure I'll need a pretty good sized sub if I go that way. Opinions??
     
  2. John Garcia

    John Garcia Executive Producer

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    Large drivers does not mean they can cover all the way to the bottom octave, and often does not. So by not using a sub you'll actually be missing out on the lowest bass. Not to mention, if you run them as large, which you would have to do if you don't use a sub, your receiver will have to deliver all the power to produce the low frequencies. That means to fill that room with adequate bass, you'll need a pretty powerful receiver to drive those speakers. Low end receivers may clip and damage the speakers in such a situation. A powered sub will reduce the amount of work your receiver has to handle because the sub is handling the low frequencies, which require the most power. In other words, I'd get a sub.

    Yes, you will need a pretty decent sub for a room that size, but it doesn't to cost an arm and a leg. Not a good sized sub, just a good sub. Check out the offerings from SVS and HSU. What's your approximate budget?
     
  3. DavidCooper

    DavidCooper Stunt Coordinator

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    As usual Mr.Garcia is correct! You really need a sub..those full range speakers will not actually give you "full range". DVD's these days have some serious low end that you would be missing. Not to mention a good suub (SVS or HSU) will give you clean accurate bass.
     
  4. Jeff Gatie

    Jeff Gatie Lead Actor

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    Forget this thinking. Start thinking that having a sub will allow the mains to do what they are supposed to do, which is give clear, powerful sound in the frequencies they are optimized for. The mains that can play optimal sub-bass are few and far between, never mind the power that you would have to purchase in order to drive them. Besides, it is better to have a single point source for sub-bass so as to eliminate nulls and peaks due to cancellation.
     
  5. LanceJ

    LanceJ Producer

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    Do y'all know what speaker he is talking about?

    The D9 isn't some dinky little satellite model. And while these speakers may not reach to a flat 20Hz, from personal experience I know the amount of bass they do have can be frightening.

    This series of CV's are also very efficient: the present version of the D9 has an SPL rating of 102dB (click on "E series", then "E-715"; use browser's "full screen" feature to see additional text at the bottom). So I wouldn't worry too much about a receiver being overtaxed. And while it seems that some speakers seem to sound clearer when they are crossed over, that can be an illusion: for example, many people think that small monitors have better clarity but only because of their lack of lower bass, even if they use the same tweeters and/or midranges as the larger speaker i.e. one of those relative things.* Same with a speaker that has had its lower bass signals removed. This effect has nothing to do with the amp being stressed out.

    I will admit that a true subwoofer would be needed to reproduce that last bit of extreme low bass the CVs can't provide, but with a 20X40 foot room Scott would need a very large sub--or subs--to totally fill it with bass below @25Hz.

    Also, if a person doesn't listen at reference level--and no one is required to do this & I don't care what the director wanted--the CVs can probably provide enough low bass so a sub might not even be missed.

    If possible, since subs generate most of their bass we hear only because of their corner/floor placement, maybe the D9's could be placed near the corners of the room? The center channel will stabilize the central sound effects.

    * this concept is put to use with many small speakers to make them sound more balanced: the tweeter's output is purposely depressed so that the overall frequency output is more balanced. The BBC LS3/5A studio monitor is a good example of this. It's extremely complicated 2-way crossover depressed most of the output IIRC past 75Hz. This resulted in a very inefficient speaker but the perceived bass output from its 5" woofer made it sound like a much larger model. It was designed to be used on top of a studio mixing console so a large speaker couldn't be used.
     
  6. DavidCooper

    DavidCooper Stunt Coordinator

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    I would seriously doubt that placing those speakers in the corners of a 20' wide room would sound very good at all. Especially for movie watching. The imaging and front soundstage would sound pretty messed up I would bet.

    Front panning effects would seriously suffer in a set up like that.
     
  7. Mark--M

    Mark--M Stunt Coordinator

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    Ahhh D9's bring back memories. I bought a set 4-5 years ago as the frist decent pair of speakers I ever had. The bass from these things is insane, you really have to experiance a set running off a powerful amp to understand what they are capable of.

    The output is defenatly there, but as some said they do start to roll off fairly quickly when the bass gets really deep. From maybe the mid 30's to 80hz or so they sound great I have to say. I found that there was an annoying resonance at higher bass frequencys when playing loud.

    The D9's are fun speakers for sure, but in all honestly you may be better off with a set of smaller, more modern speakers and a powered sub. Bi-amping by using powered subs defenatly seem to be the way to go, it provides awesome bass and it creates much more headroom for the remaining frequencys. And since bass is defenatly the D9's strongest point, they are probably not the best choice if you have a sub and wont be using the bass from the mains.

    I'd probably just use them alone as mains for now and if youd like to upgrade down the road, buy a powered sub and at the same time get some newer style mains. You should see a big improvement there for sure.
     
  8. Wayne A. Pflughaupt

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    That’s not the whole story, though. High passing a speaker means the woofer cone is no longer forced into the physical excursion needed to reproduce low bass. Less excursion means less distortion, which often translates to better clarity. (By the way, I'm not sure a studio monitor is the best example of this. They usually require high frequency attenuation simply because of their close proximity to the listener.)

    Certainly, the usual wisdom about high amplifier power needed for high bass output doesn’t apply well to highly efficient speakers. Most of Cerwin Vega’s models – especially the older ones – are high-efficiency designs, so that’s something Forum members should keep in mind when responding to questions about them.

    Still, the trade-off for high efficient speakers is generally poor extension, so I expect that Mark’s assessment about the D9’s sagging response below about 35 Hz is correct.

    In Scott’s situation with a huge room – 6400 cu. ft. assuming an 8-ft. ceiling – the D9’s “huge bass” probably falls like a brick below 40 Hz. It will take a fairly substantial subwoofer – perhaps even a pair of them – to achieve the kind of SPL level and impact most of us like our home theaters to have.

    Regards,
    Wayne A. Pflughaupt
     

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