Protecting speakers in home theatre application?


I have an Adcom preamp and amp (GFP-565, GFA-535 II) driving a set of B&W Nautilus 804s. I am considering using this with a new TV via a (yet to be purchased) DAC, but I am wondering whether driving the speakers with TV / movie audio with non-music, non-voice special effects audio audio risks damage to the speakers. This includes signal drop-outs / and static-bursts since the HDTV tuner will be over the air broadcast rather than cable.

I looked for prior discussions but did not find them. Any thoughts or pointers to other discussions?

One final comment- I care most about music, not TV and movies, which I just need to hear. I’m not trying to build a theatre. So, I’m hoping to get a rather cheap DAC and maybe a cheap line-level pre-amp with a remote volume control. These components could also be a worry. To be clear, the setup would be to take the digital TV signal via toslink to a DAC; take the line level from the DAC by RCA to the in-line volume control and from there to an AUX in of the Adcom preamp. For music, my CD player goes into another input of the Adcom pre-amp and is free of all this new nonsense...just CD, Adcom pre-amp, amp, and speakers.
efrank
What I found is that home theater and high end stereo, don't do well together.   I have each of mine in a different room of the house and am very pleased.  I can max out each of their particular traits much better that way.
My hi-fi is also in a different room in "the mansion" than my TV…I've issued hover boards to all the servants by the way, so as to lesson all the pesky foot noise (highly recommended). I use an old receiver for the TV, and run a signal from the "big screen Sony" (a line from "Pretty Girls Rule the World" recorded  by David Lindley) to the receiver which is used in stereo mode (not surround as I don't care) powering my very old Boston Acoustics A60IIs (which sound great…replaced the woofers at some point)…and it does the job. A line from the DVR provides signal to my Sony wireless headphones so I can silently watch stuff after the servants and my wife go to bed (not with each other hopefully as I'd hate for the servants to not get enough sleep).
Wolfie- you crack me up, man!  But given what we now know about hover boards, I hope you've got a hold harmless clause in their contracts 😜
Thanks for your comments. I must fit everything into one room. In any case, I'm still left with the question of whether there is a risk to the speakers.

I can't speak directly about your B&W 804's but the Klipsch RF-63's I have been using since May 2008 have taken everything that I have thrown at them.  From very demanding 2-channel music to very complex and dynamic high resolution BD movie effects to TV/Netflix fed with toslink to DAC to preamp/processor.

I had an OTA HD antennae for a while with it's static bursts and dropouts and never experienced any ill effects.  If my RF-63's(msrp $2000.00) can take some abuse, I would think your 804's(msrp $7000.00) could also.

Are you more concerned with your tweeters, midrange drivers, or your bass drivers getting fried?

Bill
Contracts? Risk of deportation obviates contracts. My servants all carry small fire extinguishers and wear helmets…because I care. Note that the primary risk to speakers is extreme distortion from a SS amp played too loud, direct current from a failing amp of any kind, and curios probing fingers squishing a tweeter.
Here's a professional home theater review of a Nautilus 804-based 5-channel HT setup:

http://hometheaterhifi.com/volume_8_1/b&w-nautilus-home-theater-speakers-2-2001.html

I've been running Mirage M5si's as the mains in my 7.1-channel 1.4KW HT system for 19 years with no problems. 

The main thing to watch out for would be if you watch lots of movies with explosions and car crashes, in which case you'd want to high-pass the signal to your 804s at 40Hz or even a little higher, and let a home theater-worthy powered subwoofer handle the special effects low frequencies.
Wow, such compassion.  A true humanitarian.  I nominate Wolfie for human trafficker of the year!
I mean, a less right-minded audiophile would protect against finger-squished tweeters like this
https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcTc1L2qtLyq6wkLFCZncE-BlUmzA1Pp_UCxReHcBRTIyX7P...
Excellent- I'm quite reassured! Probably the biggest risk, then, is the cheap DAC I was going to use (Orei DA34). If I could be absolutely certain the TV put only 2-channels over the optical, I'd switch to the Schiit Modi Uber.

Willand- What DAC were you using?  (The 804s were about 3k rather than 7k back when I got them.)

Wolf- I have to take exception with your list of dangers. You forgot cats. 


I have a pair of B&W 804S connected to my TV/Ht system, driven by a Cambridge Audio 840 pre-amp and a Parasound HCA1500 DC coupled poweramp.

My DVD Blu-Ray is an Oppo 95.

I generally do not have problems with most materials, except for a recent playing of the movie Interstellar. The subsonic energy is so high in level for some scenes I thought my bass drivers were being damaged. The ports were puffing out air like you would not believe. In some of the loudest passages, the bass drivers were rattling.

This could obviously be damaging to the bass drivers.

How to protect them?

a) Use a subsonic filter. Not easy to find these days and they do impact the SQ in the audio range.
b) Use a foam ball in the ports. This will raise the lower frequency response point (unfortunately) but will prevent violent excursions in the bass drivers.
c) lower the volume levels (what I did). Not the best solution either.
" Willand- What DAC were you using?  (The 804s were about 3k rather than 7k back when I got them.)"

I am using a Cambridge Audio 840C player/Dac.  When streaming Pandora from my TV I let the 840C upsample to 384kHz/24-bit but with Netflix I let the Dolby Digital 5.1 signal pass through unaltered to my NAD pre/pro.

Bill


My Silverline Prelude tweeters have little screens on them to supposedly help acoustically with treble dispersion or something, and are thusly protected. I was talking about this with a sales dude at Goodwin's once…the groovy  Magicos have a beryllium or non-obtainium or mondo expensivium tweeter sitting there just daring people to touch them, and he said, "uh" or "murmph" or something…amazingly, many other extreme high end speakers have exposed tweeters which is fine I suppose if you never let other humans near them.
My pre-amp has inputs / outputs for an external signal processor. Any reason why I could not put a filter there if I decide to do so? The advantage to this is that, on this preamp, there's a button to remove the external signal processor from the signal path, which could be done for non-TV listening.