Can someone explain HT bypass to me?

mistuk

Standard Member
Hi there,

Could someone explain, or point to a good explainer of HT Bypass for me?

I've currently got a Marantz NR1607 receiver connected to a 5.1 speaker system. I've recently purchased a turntable and an iFi phono preamp.

I want to get a better amp for music - most of my music comes from Apple Music, but my wife likes the turntable. I want to upgrade the Front left and right speakers and I'm currently thinking about the KEF LS50 meta speakers (currently got B&W 601S3).

I'd like to use these for FL / FR when watching films etc, but also to use them as my stereo speakers for listening to music.

Probably most likely to get the Lyngdorf TDAI 1120 as the amp / streamer,

Will I be able to achieve what I'm looking for, and if so, can someone walk me through how I'd connect it up?

Many thanks

mistuk
 

Ugg10

Distinguished Member
The basic idea is to take the front L/R preout signal from the AVR and put this through a stereo integrated amp which is connected to the front L/R speakers. teh front L/R speakers are therefore not directly connected to the AVR.

In AVR use the Integrated Amp is set to "bypass mode" (also called processor mode and other things depending on the manufacturer) which turns it into a power amp with the volume controlled by the AVR via the left F/R pre-outs (not any room EQ in the AVR if it has it will need to be rerun once the Integrated stereo amp is setup).

For Music mode, the AVR can be switched off and the Integrated amp set to whatever source you want to use and off you go, volume is controlled by the integrated amp.

All multi channel sources (blue ray, DVD, TV Box etc.) are connect to inputs on the AVR and stereo sources (Turntable, CD, Streamer etc.) are connected to the inputs on the Integrated Stereo Amp.

Hope this helps.
 

camcroft

Well-known Member
A home theater bypass is a feature found on high-end integrated amps used in home theater systems. It is used to connect an external two-channel stereo system with a surround sound home theater system via RCA. This feature allows you to bypass all of the complex digital processing of the integrated amplifier.
 

Nico72

Active Member
In simple terms, HT bypass on an integrated amp is a particular input with fixed gain, so you cannot change the volume of that input with your integrated amp
You connect the pre out of your AV amp to that particular input on you integrated. This way, the volume is unaffected by the position of the volume knob on your integrated, but is controlled only by the AV amp, when you watch films or TV.
All other stereo sources must be connected directly to the other inputs at the back of the integrated amp as normal. They must not go though the AV. The front speakers must be connected only to the stereo amp.
If you don't have an input with fixed gain, you must remembered to reset the volume of the stereo integrated amp always to a fixed position before selecting the AV source for watching films. HT bypass does it for you.
 

ShanePJ

Well-known Member
AVForums Sponsor
So, thankfully you have front pre-outs which means you can use any stereo amp which uses this feature.

Simply put, when using one of these amps, one of its inputs can either be switched to or is fixed whereas the other inputs are variable allowing you to adjust the volume. This then means that when you plug your avr into the fixed input on the stereo, you can control the volume via the avr without worrying about having to faff with the volume settings and trying to match them thus it becomes a dedicated power amp for the avr.

Moving over to the stereo side alone, all the other inputs work just like a traditional integrated stereo amp allowing you to plug all your dedicated stereo electronics into it

Now as you are streaming, this will ultimately depend upon the quality of the streamed music as you cannot make poor quality music sound amazing as it will always be poor quality and when you do try to improve it, you also improve the poorer side of the music to. This is something completely different to using an amp which takes advantage of the HT-Bypass solution. This area will require you look at the quality. So if its CD or a higher level of streaming quality, then you should hear a different going down the HT-Bypass route whereas if its less than CD quality then you could in fact introduce a worse sound experience as you will be amplifying all areas which also means the poor stuff to

The Lyngdorf is a great product and will bring the very best out of the Kef's, but do be aware that if you place the Kef's close to the wall, they do require some room and this would not be the best thing you could do to them
 

Timmy C

Distinguished Member
Ugg10 beat me to it and has covered what I was typing out. One thing to keep in mind though. If you are connecting your sub to the AVR for LFE as I'm doing, it won't come in to play when just using the hifi amp for stereo. There might be ways round this if your sub has dual inputs or you use some kind of input splitter but it's not something that's bothered me enough to figure out a work around.
 

password1

Distinguished Member
Ugg10 beat me to it and has covered what I was typing out. One thing to keep in mind though. If you are connecting your sub to the AVR for LFE as I'm doing, it won't come in to play when just using the hifi amp for stereo. There might be ways round this if your sub has dual inputs or you use some kind of input splitter but it's not something that's bothered me enough to figure out a work around.
Some subs allow multiple inputs. Rel and BK subs with high level input can be used withan integrated amp and the low level from the avr.
 

mistuk

Standard Member
So, thankfully you have front pre-outs which means you can use any stereo amp which uses this feature.

Simply put, when using one of these amps, one of its inputs can either be switched to or is fixed whereas the other inputs are variable allowing you to adjust the volume. This then means that when you plug your avr into the fixed input on the stereo, you can control the volume via the avr without worrying about having to faff with the volume settings and trying to match them thus it becomes a dedicated power amp for the avr.

Moving over to the stereo side alone, all the other inputs work just like a traditional integrated stereo amp allowing you to plug all your dedicated stereo electronics into it

Now as you are streaming, this will ultimately depend upon the quality of the streamed music as you cannot make poor quality music sound amazing as it will always be poor quality and when you do try to improve it, you also improve the poorer side of the music to. This is something completely different to using an amp which takes advantage of the HT-Bypass solution. This area will require you look at the quality. So if its CD or a higher level of streaming quality, then you should hear a different going down the HT-Bypass route whereas if its less than CD quality then you could in fact introduce a worse sound experience as you will be amplifying all areas which also means the poor stuff to

The Lyngdorf is a great product and will bring the very best out of the Kef's, but do be aware that if you place the Kef's close to the wall, they do require some room and this would not be the best thing you could do to them
Thanks for this - the speakers will be quite close to the wall… hmmm…. Other suggestions to try that would work closer to a wall? The blue Ls50 meta’s are liked by the wife!
 

password1

Distinguished Member
You would he surprised how good the dali specktor 2 are. Look gorgeous in the white with red cones and silver trim.
 

3rdignis

Active Member
Stereo sources connected to the avr could be used

HDMI to avr, HDMI (arc) to tv, optical to stereo system
 

jonno73

Active Member
Thanks for this - the speakers will be quite close to the wall… hmmm…. Other suggestions to try that would work closer to a wall? The blue Ls50 meta’s are liked by the wife!
The room perfect (room correction software) on lyngdorf actually advises you to place the speakers back closer to the wall; then running Room Perfect.

This was great for me as my Dali’s looked ridiculous pulled out the minimum distance they were suggested to be by Dali!
 

Khazul

Well-known Member
There might be ways round this if your sub has dual inputs or you use some kind of input splitter but it's not something that's bothered me enough to figure out a work around.

I would not suggest for most people that they even consider or try this as it is really hard to accurately blend a typical sub for dual use considering the sub would likely end up getting a slightly out of phase lower cross over and maybe lower level signal in from the second input from the hifi amp when the AVR is suppsed to be controlling it exclusively. Some subs have a input select but many just blend the inputs, or just auto select based on signal detection.

I do actually do this - it took alot of fiddling with sub placement, many repeat room measurements with REW to check results and tweak levels, crossovers etc under various combinations of use. It now works and works well for me (measurably so), but not something I would suggest for someone who doesnt have the background to understand the consequences of trying to do this and the tools to make it work and the compromises that come with it.

In future I think I would say sod it - just get bigger main speakers and not bother with a sub for music (despite that my mains go down to 40Hz, but I wanted extension down to 30Hz for music...) :)
 

butcherpete

Member
I know when I got the PS dac/pre, it to had an HT button, still got no idea what its for. I have all the speakers connected to the Anthem 520 apart fro the front 2, which connect to the PS S300 power amp. Have everything working as I want it, just alter the volume on the PS Pre if needed, as the sub is connected to the power amps connections ;-)
 

ShanePJ

Well-known Member
AVForums Sponsor
In essence the home theatre (ht) bypass feature means that the volume control is taken care of from an external source (is the volume is fixed) whereas the remaining inputs to the integrated stereo amplifier (ISA) enables full volume control like any other stereo amplifier

These solutions are especially important for people who want to get the most out of both home cinema and stereo as the home cinema amp will still be able to use it's eq system every time you power both unit on for cinema usage whilst allowing you to maximise your musical playback when just using the integrated stereo amplifier and its own volume control

So, if you use one of these ISA, then you can turn the ISA's ht-bypass input into a power amp setting (which means you also have to have an audio visual receiver (AVR) which utilises pre-outs) allowing 100% if its signal to be controlled by the AVR and for everything else, it reverts it back to a good quality and hopefully musical product when you power down the AVR and use the stereo features within the ISA
 

ShanePJ

Well-known Member
AVForums Sponsor
As for using multiple subwoofers with dual inputs like high-level and LFE, Its always best to use speakers which naturally allow the bass to roll off and as many manufacturers to peak the bass which allow the speed of the bass to accelerate, this is why it can be so difficult to partnership systems of this nature. Now with room corrections solutions, they basically stop the speaker from reaching this area and allow the woofer to compensate.

Explaining it in another unscientific way, if you're stood in the middle of a flight of stairs, the woofer is on the bottom step pointing upwards towards you and the main speakers are on the top steps point downwards you, then in a round about way, so long as the distances are equal, the sounds that the speaker produce should hit you at the same time as the woofers sound and thus create a balanced and unseparated experience as you hear the full range of partnering products.

In reality, this kind of explains what you will be trying to achieve, but if you are unable to turn the peak power of the bass speed from the speakers and if the woofer is not married so it delivers the sound so you can hear the miss alignment. You will be left with is either a void of sound (known as the Sub/Sat Void). This can be either because the woofer is unable to hit the higher frequencies of the speakers or the speaker accelerates bass creating false bass notes which will never pair with a natural woofer giving you a miss-match

As a rule, if you use an AVR for both stereo and cinema, then you can use the speaker level (cut-off) to better control the miss-match meaning it is much easier to integrate a subwoofer and speakers for stereo usage with both high-level and LFE control. These miss-match usually is something people experience with bookshelf speakers whereas with floorstands, not as many accelerate the bass levels and its usually poor positioning that cause the miss-match

If you want to use this feature, then I'd use smaller bookshelf speakers like the Monitor Audio Radius with a good quality woofer which delivers a musical bass level. You will be amazed that even tiny speakers like these will fool many ears when used in conjunction with a well setup subwoofer in a stereo format as they deliver a sound which is closer to Monitor Audio Silver series than the system will ever suggest

The key is using bookshelf speakers which allow the bass to naturally away or ones where the acceleration of these bass levels are inaudible due to the size of the drivers which makes them produce a weak bass level allowing the natural bass of the woofer to shine through

I've been using a high-level input with LFE for more than 15 years in my setup with various speaker/woofers combinations to great effect, so it's possible so long you are aware that some combinations will never work together because of the way the speaker pushes its bass frequencies out unless you use sophisticated software to iron these areas out

Now the room is another story altogether where it will have just as much of a influence of how both speakers and woofer interact with each other
 
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Khazul

Well-known Member
Heh - normally when this subject comes up you get all the hifi purists jumping in a severely condemning the practice as if it were a sacrificial demonic ritual :)

Kind of refreshing to see someone from a dealer actually doing this too. Sure its a pig to set up well., but worth it for me.

For a modern music musician with a little bit of basic audio physics and tech background it is possible to get good enough by ear (as they may know the notes to pay attention to) particularly if they accept that a compromise has to happen somewhere (on the AV sub side in my case and TBH my AVR seems to mostly deal with it well enough via its auto-setup).
 

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