Is power of full range enough for home theater application?

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Is power of full range enough for home theater application?
I want to build speaker of home theater with full range driver.
I will use not expensive denon receiver with about 110wt per channel.
Through dimension of rear speaker I’m forced to use 10cm, 4” drivers.
In the rear speaker I can put two drivers.
I think about drivers to use
1. Ciare HX100 – 25wt. Two driver-50wt. http://www.ciare.com/pdf/catalogo/HX100.pdf
Paper cone.
2. Omnesaudio BB 3.01 only 15wt. Two driver-30wt http://www.lautsprecher-selbstbau.biz/
Appearance more beauty then Ciare.
3. Some of Tang Band driver I think the same as Omnesaudio BB 3.01 with low powering possibility.
4. Jordan the best choice, I guess, but expensive, will only use if others are not satisfy my powering needs. Is senility of Jordan enough for receiver?

So I need my rear speaker be OK with power of receiver.
What do you suggest me for my rear speaker in HT?
I guess in front I should use the same 4 or 6 drivers.
 
Greets!

It all depends on how loud you want and how far away you plan to sit from the screen. If it is only at typical TV viewing loudness (~75 dB average) and <8ft viewing distance, then FR drivers combined with bass management and sub(s) will work fine. If you want to use DD/DTS reference levels (85 dB/channel/listening position), then no FR drivers come to mind at the moment that can handle it without a midbass driver as well as a sub system.

It's been awhile since I last checked, but inexpensive HT receivers' power ratings were pretty optimistic, but FR drivers can't handle a lot of power so it shouldn't be a problem.

The receiver barely has enough power for the Jordans IF it can actually output 110 W at lower impedances, which I doubt. Better to use more efficient drivers and BW limit them to 80 - 120 Hz depending on the receiver's LFE XO point/slope options.

GM
 
Please clarify...

If you want to use DD/DTS reference levels (85 dB/channel/listening position), then no FR drivers come to mind at the moment that can handle it without a midbass driver as well as a sub system.

I was thinking of building some speakers using Full Range drivers for my home theater (really more of a glorified media room). My seating position is about 10 feet from the speakers.

Are you saying that a pair of Fostex FE166, Jordan JX92S or CSS FR125s wouldn't be able to handle 85dB's if the bass management crossover was set at 100hz and a subwoofer was used?
 
I think he means that the reference level implies an 85dB base level, to which are applied the peaks the occur (screaming, crashing, shooting, exploding, what have you) that can easily 20-30dB or greater above your base level. And when those peaks occur in the bass regions, the amount of power needed for them is quite large compared to the same peak in a high frequency region. This sort of power will require a large Xmax in the driver which is not something to be said of most fullrangers. So you'll end up driving most full rangers to distortion or even damage if you listen to HT material reference or even at more modest levels.

All FR units will provide 85dB power within their range, but i don't know of any that will go to 115dB without A) sounding like crap or B) bottoming out. Also, I don't know of any way to configure an FR unit to really hit the lower octave or two, and even with the best drivers and the best bass reinforcing cabinets, you won't get that lower end very loud (I doubt you'd be able to get 50Hz peaks at greater than 95dB without distortion no matter how much money you throw at the problem).

Of course, the higher you cross your FRs over to a sub, the louder they'll be able to go without danger or distortion. I wouldn't want to go higher than 80Hz (the THX spec, and a generally agreed upon rule of thumb for the limit of perceived directionality in bass). Personally, I run my Kenwood KFC-6469s down to 60Hz in OB configuration (yeah, they're car speaks so they're engineered to be more rugged, have greater Xmax and all that, though they probably give up some mid and high end quality to many of the finer, not to mention, more expensive drivers). Trying to EQ more bass in just causes distortion at all levels, but crossing out the bass below where they acoustically roll off actually makes them sound cleaner. A little sub in the corner behind them running on a decent plate amp that can cross low enough gives me another octave on the bottom is well more than adequate in that room.

I'm sure some of the guys that have already used the drivers you're looking at will chime in on the designs they're using. There should be a good compromise floating around here somewhere.

Kensai
 

GM

Member
Joined 2003
Re: Please clarify...

Greets!

DD/DTS reference is limited to 20 dB of dynamic headroom (105 dB peaks) in the main/surround channels and coupled with loss over distance of up to ~9.7 dB, none of these can come close without either significantly exceeding its Xmax and/or rated power handling. Any decently designed/manufactured driver can easily withstand 2-3x its power rating, but Xsus and Xmech (suspension/bottoming out limit) WRT Xmax is a design variable that may only cause increasing distortion (like Fostex) or potential mechanical failure (like CSS) when overdriven.

As always though, what an individual accepts as OK performance isn't so well defined (just look at B*** success), so as always YMMV.

GM
 
After some hesitation I started using my Jordan streo pair (jx92s,MLTL 48") also in home theater front channels (without center speaker).

They sound really great for the movies,specially at my setup without the center channel,cause their stereo image is so accurate.
I never use very high sound levels,but after the first action scene I decided to cross the Jordans at 80Hz to the sub.It felt like raping these fine drivers as they needed to work hard to provide the bass.Now when crossed thy seem more relaxed and the sound really is great.
 
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