Should I use the receiver's SUBWOOFER OUT channel?

[Poo]

What are the pros and cons of having the reiceiver feed into the high level inputs of the sub and the front speakers connected to the high level outputs of the sub? Doesn't this seem to provide more integration?

Also, I tend to look at movies for hours upon hours. Wouldn't this 'overheat' the sub's amplifier? If so, can I aim a small fan on the amplifier to help dissipate the heat? I am nuts about overheating. My computer has 8 fans and loud as heck!

Thanks

[Dudley]

During most of the time for most movies the subwoofer is not being taxed too hard. I would not worry about overheating unless you have a bass heavy scene on repeat for hours at a time.

If you use the high level inputs, then you are running without a sub as far as your reciever is concerned - not a bad thing, but you need to be aware of this during setup. You just have full range main speakers.

You may need an awfull lot of speaker wire to put the sub behind the listening position with high level inputs.

[Sasha_G]

Originally Posted by Poo

What are the pros and cons of having the reiceiver feed into the high level inputs of the sub and the front speakers connected to the high level outputs of the sub? Doesn't this seem to provide more integration?

Also, I tend to look at movies for hours upon hours. Wouldn't this 'overheat' the sub's amplifier? If so, can I aim a small fan on the amplifier to help dissipate the heat? I am nuts about overheating. My computer has 8 fans and loud as heck!

Thanks

With modern Dolby Digital receivers, the crossover is handled digitally and all integration is handled there. Both the high pass crossover and the low pass crossover duties are handled and easily changed with the receiver controls--even the remote control often.

The disadvantage of having the integration handled by the subwoofer is that more cables back and forth are needed, without better results.

As for the heat issue, a fan is not needed since most of the time, the full power of the amplifier is not called upon. Also, since we are using BASH amplifiers, there is very little heat.

I have just purchased the VTF-2 with a new set of Ascend Acoustics speakers for my home. I am using the speakers with a NAD T760 A/V receiver. I plan to use my setup for both stereo music and 5.1 surround with movies. I have the VTF-2 plugged directly into the subwoofer out on the T760.

If I switch the T760 into "Stereo" mode I tend to lose the VTF-2 and I only get sound out of the R/L Ascend fronts. Although that does sound somewhat logical to me, I was definitely hoping to use the sub in tandem with the fronts when listening to music only content.

Is this a normal tradeoff or is this somehow particular to my receiver? If I use pre-outs to the R/L ins on the VTF-2 and freq adjust will that result in a system that allows me to switch more fluidly between the two output modes?

[Dudley]

Not familiar with that model, but you may have to fiddle with the bass management. My subwoofer kicks in on any source.

Originally Posted by Dudley

Not familiar with that model, but you may have to fiddle with the bass management. My subwoofer kicks in on any source.

Yeah, I've been through all the menus. And I know it is hooked up correctly because it obviously works when it is in Dolby Digital or other surround modes. The sub simply is not getting a signal when in Stereo mode. It's very frustrating. I suppose it may be a problem with the receiver.

Replying to myself here. It appears that my A/V Receiver (NAD T760) just has this limitation. I'm asking a friend to test his to be sure. This receiver simply does not send a signal to the sub when stereo/analog is selected. It's basically only available to the surround modes supported by the receiver.

[Sasha_G]

I recently found out from Dr. Hsu that there are a few Dolby Digital models that actually don't have bass management in 2 channel mode or the SMALL speaker setting! I always thought all Dolby Digital receivers provided this functionality. I know that the Sony, Denon, and Onkyo units I've seen DO have it, and would assume that major brands like Panasonic do also.

Playdrums,
I'm not sure about the NAD--you would have to ask the makers. I've was told by Dr. Hsu that even some Marantz units, including their expensive ones, don't have the bass management in 2 channel mode.

[ilikeitdeep]

I'm using a Rotel RSX 1056 and it's not a problem for me. Stay away from NAD.

Thanks ilikeitdeep, that was helpful.

Sasha,

I found this to be exactly the case. My NAD T760 does NOT have bass management in two-channel stereo mode. Their newer lines do not have this issue btw. I can also confirm that other makes/models (including Rotel), especially from 4 years ago or so may have the same issue. The following is from an old, archived faq from the NAD site about this issue. Sasha, of the workarounds listed, which do you think will produce the best results with my new sub? No. 2 is too much hassle I think.

(I'm also considering a new receiver. How do people feel about Harmon Kardon?)

------------------------------------------------------
How should I set up my subwoofer connections with the T760 to operate the subwoofer for stereo recordings as well as home theatre movies?

There are three options, made necessary by Dolby Lab's configuration of the Dolby Digital chip:

1. Attaching both the speaker level outputs and the coax subwoofer out to the powered subwoofer gives you full range sound in stereo mode and the .1 effects channel in 5.1 surround modes.

2. Call up the set-up menu in the On Screen Display, and set "center" to "off" and set "surround" to "off". Exit the set-up menu. Select the EARS surround mode. You will now have stereo with the sub out active.

3. You can also use bass management Preset 2 and attach the subwoofer to the two front channels via speaker level inputs as you would for a strictly two channel system. This is also a good setting to use with "powered towers"; full range speakers with active subwoofers built in.

[Sasha_G]

Hmm...

Solution #1 has the problem of the subwoofer's volume level being different between the coax and the line level...you might need to adjust the volume level every time you switch. Make sure to set the front speakers to LARGE as well. We don't recommend this approach.

Solution #3 looks good. Usually, this works well, as long as your main speakers are not too big. Since you are using bookshelves, the subwoofer will augment the bass as it rolls off, leaving a nice "natural" crossover between the sub and speakers. The HSU will tap into the bass routed to the left and right speakers. The surrounds generally don't have any bass, and the center doesn't have that much also, so you won't miss much.

One more thought...if your NAD has an extra PRE-OUT, you can implement a switch box system that I tried to describe here:

http://www.hsuresearch.com/?p=99

Basically, you plug in the PRE-OUT and SUB-OUT to the switch box, and switch between the signal the subwoofer will get. You probably don't have to switch the crossover in and out like my previous post describes. In your case, since the crossover will be about 80 Hz for the Ascends, you could leave the HSU's crossover to IN and it should work.

Let me know what happens

[Dudley]

You might be able to hook your sub up to your "B" main speakers on the reciever. Keep your fronts on the "A" speakers. This will do two things. It will allow greater flexibility with sub placement without quite so much cable, and it will allow you to easily turn the sub off by turning off the B speakers.

Of course this assumes that your reciever puts out identical info on the A and B speakers, and will let you run A+B while doing surround sound - it may not (my Onkyo 600 will not).

Option 2 is not as much of a pain as you might think if you have a programable remote with macros. I have a TV with a widescreen mode that is great with 16 x 9 anamorphic DVD's, but takes about 14 buttons to access on the remote. I just programed a macro to do all of that with the push of one button.

[Lizard_King]

i plan on using an Outlaw Audio 1070. Will I be able to play 2 channel Stereo and use the VTF-2 with the speakers?

Originally Posted by Sasha_G

I recently found out from Dr. Hsu that there are a few Dolby Digital models that actually don't have bass management in 2 channel mode or the SMALL speaker setting! I always thought all Dolby Digital receivers provided this functionality. I know that the Sony, Denon, and Onkyo units I've seen DO have it, and would assume that major brands like Panasonic do also.

Playdrums,
I'm not sure about the NAD--you would have to ask the makers. I've was told by Dr. Hsu that even some Marantz units, including their expensive ones, don't have the bass management in 2 channel mode.

[KC23]

sorry wrong thread

[PhantmShado]

Hey, further question for this thread: If the speakers are wired through the subwoofer from a 2.0 amp/reciever, does the subwoofer strip out the lower frequency signal before passing onto the other speakers, or does it just branch off the wire and play the part it is told to play while passing on an untouched signal? I can't seem to find a definitive answer on this.

Also, if it is the former case where it strips out some signal, would this really have no effect on the sound that ultimately reached the speakers (besides giving them no low frequencies to play)? It seems to me that it should affect the sound to alter the signal in anyway, but I'm not anything of an expert in these matters.

If it helps the subwoofer I am using is an STF1.

[Pete_Hsu]

On the STF series, when using the high level inputs and outputs back to the main speakers, there is no circuitry there to block low frequencies going to the main speakers. So the subwoofer will be used purely for bass augmentation.

Sincerely,

[Boston Bob]

I have a stereo preamp w/o a sub output. Does it make any difference, sound-wise, if I use a "y" connector to split the preamp outputs to the sub vs. using the high level inputs from the amp? If I use the high level connections on the sub, can I use a speaker switch and run the sub as a separate speaker, allowing me to toggle the sub on and off without compromising sound?

[SME]

If you can, it's better to connect the sub to the pre-outs. You may also want to consider purchasing one of these:

http://hsuresearch.com/products/high-pass-filter.html

Install the high pass filter between your pre-amp and your amp. The filter will remove the bass that your sub handles from the signal sent to the mains. This will give you much more headroom for the mid and upper frequencies handled by your mains and may also help prolong their life. You'll need to decide which crossovers you want. What kind of speakers are you using?