Home Theater Systems VS. Music Systems

[mtrycrafts]

If transient response is good, the speaker is described by people as fast. This discussion is dumb.

Actually, it is not a dumb discussion. Sloppy usage begets misconceptions, urban legends, myths, bs, etc. We have enough of these already.

Best to stick to accurate, accepted technical language, your disagree?

 

[Francious70]

Here, let me throw this in for you to chew. The higher the inductance of the voice-coil, the longer it will take for the tranducer to start to move when a signal is recieved.

AND the greater the group delay, the more delayed the bass will sound.

 

[miklorsmith]

Sloppy usage begets misconceptions, urban legends, myths, bs, etc. . .

Greek isn't Greek to a Greek, eh?

 

[jaxvon]

Here, let me throw this in for you to chew. The higher the inductance of the voice-coil, the longer it will take for the tranducer to start to move when a signal is recieved.

AND the greater the group delay, the more delayed the bass will sound.

I already touched on this with the links I posted. But it's always good to reinforce the ideas.

 

[mulester7]

I'd be happy with a sat/sub combo for HT with lots of speakers. For music, this arrangement would drive me insane. A system must be more convincing and competent to cut it for music, where I'm much more forgiving for movies.

Bass isn't bass isn't bass either. Down-firing vs. front firing, port configurations, and ROOM EFFECTS have a huge role to play. How about ported vs. not? Gimme ports and SPL for movies, and speed/sealed for music. Speed applies to speakers/subs, no question.

.....major ground is covered in the second part, MiklorSmith....as for the first part, it would seem you could be content with lesser speakers and lesser sound quality with Home Theater....so, should we take an attitude toward HT usage that is different from listening to music?......

 

[bpape]

... or a compromise between the 2 - the passive radiator. Fixed air volume but some of the 'spring' used to push the PR. Some people abhor these designs as they say that the 2 drivers are inherently out of phase with each other. When dealing with room interactions, that can actually be a benefit. Not to mention the fact that you're getting extra air movement with only the power requirements from the single driver.

I'll also plead guilty to using the term speed instead of transient response which is more what I was referring to. I will, however, question the proposition that mass does not affect transient response.

With the same motor, the heavier cone will be slower to start. Now, if you increase the cone mass AND increase the motor capabilities accordingly, then I'd agree. Just because a driver is more massive doesn't necessarily mean that is has poorer transient response.

 

[Francious70]

Actually, the moving mass has little to do with transient response, it's the inductance of the voice-coild that makes the difference. More mass just usually means a less sensitive or "efficient" speaker.

 

[mustang_steve]

I just see it as something that matters for budget systems.

A budget music system will often have quality, but lack in volume.

A budget HT will often have high volume, but lack in quality.

My HT setup is a prime example of a extreme budget HT....less than $900 tied up in the thing, receiver, speakers, subwoofer, TV, stand, etc. It definately lacks inquality....the sound is nice, but it lacks detail and is nearly incapable of playing some movies at anything lower than 50% volume without losing significant portions of the sound (stuff like whispering voices).

As you get up in prices, there is less need to compromise.

 

[miklorsmith]

so, should we take an attitude toward HT usage that is different from listening to music?......

I'm merely stating my view that movies can be quite enjoyable with far less competence than music. Heck, I don't mind watching movies with the freakin' TV speakers. But remember, I'm unusual and you shouldn't listen to me. I use a battery powered DAC, a tubed preamp, a battery powered, 6 watt amp, and (gasp) 2 big, efficient speakers.

Holes in bandwidth and dynamic punch with music anywhere from 30 hz to 15 khz are obvious and detract from the experience. Accuracy of spatial representation is very hard to get right and beguiling when it is.

Movies can have holes all over the spectrum if sub bass is good and the dialog is intelligible. Adding channels isn't a big deal to me either. Explosions need SPL's to be effective in a movie setting, but the same "skill" can be a horrible detraction in a music rig.

My 2-channel rig is good and there's no way I'll get anything better going multi-channel without spending way more dough. Thus, whatever winds up in my stereo is the system I use for movies. It eliminates the additional heartburn trying to optimize two separate systems where I have a hard enough time going the right way with my one system of choice.

Plus, I'm a fan of spending on fewer, better parts instead of more, inferior pieces.

So, to me, the "perfect" stereo, music rig is killer for movies and way more than I need.

I certainly don't pretend to know what others like in their systems and I'm definitely not telling people what to do with their purchases and priorities.

 

[mulester7]

I'm merely stating my view that movies can be quite enjoyable with far less competence than music. Heck, I don't mind watching movies with the freakin' TV speakers. But remember, I'm unusual and you shouldn't listen to me. I use a battery powered DAC, a tubed preamp, a battery powered, 6 watt amp, and (gasp) 2 big, efficient speakers.

Holes in bandwidth and dynamic punch with music anywhere from 30 hz to 15 khz are obvious and detract from the experience. Accuracy of spatial representation is very hard to get right and beguiling when it is.

Movies can have holes all over the spectrum if sub bass is good and the dialog is intelligible. Adding channels isn't a big deal to me either. Explosions need SPL's to be effective in a movie setting, but the same "skill" can be a horrible detraction in a music rig.

My 2-channel rig is good and there's no way I'll get anything better going multi-channel without spending way more dough. Thus, whatever winds up in my stereo is the system I use for movies. It eliminates the additional heartburn trying to optimize two separate systems where I have a hard enough time going the right way with my one system of choice.

Plus, I'm a fan of spending on fewer, better parts instead of more, inferior pieces.

So, to me, the "perfect" stereo, music rig is killer for movies and way more than I need.

I certainly don't pretend to know what others like in their systems and I'm definitely not telling people what to do with their purchases and priorities.

.....EXCELLENT post, MiklorSmith, this was you.....

.....(guys, he needs to blend in one pair of split rears and get stereo surround....with any surround situation, the front two get twice as wide, and the mids become explicit.....

 

[Resident Loser]

Sorry...

...I'm too lazy to read through the entire thread, so if some of this has already been said, my apologies...

IMO HT isn't nearly as demanding from an "audiophile" POV...You need loud...you need directional cues...you need LFE...accuracy is not paramount.

If you take a look at some "state-of-the-art", pro-installed, HT rooms many of them seem to use "pro" type loudspeakers...and by that I mean studio monitors, more suited to post-production work than to audiophile-type concerns.

Let me clarify a bit...not that they are inaccurate or completely unsuitable(they aren't) but, many of these products are simply not used in accordance with the manufacturers intent. If you take a product that is designed to be a near-field radiator with quite specific placement guidelines(in order to present a proper image and exhibit a smooth FR) and place them contrary to those suggestions, something has to suffer. Yes, they might be able to handle a great deal of power and yes, they may be able to present an enjoyable soundfield but...watching a movie and HT in general, isn't quite the same as listening to a strictly audio presentation. In addition to that, the sound is processed(LFE, surround, etc.) to enhance the visuals and in some respects, take up the slack; it's a package deal...with audio you get audio, no distractions.

Laser-totin', mechanical lizards don't quite require the subtleties of a string quartet. IMO two dedicated systems is probably required for optimum enjoyment of both mediums. Failing at that, I would opt for the best reproduction for audio. While it may not be optimized to shake the rafters(although in some cases it might), if it presents a good, stable image with a wide and smooth bandwidth, it should be more than sufficient to provide a reasonably satisfactory HT experience...after all it's only tee-vee.

jimHJJ(...TTFN...)

 

[miklorsmith]

Yeah, RL. That's what I Meant to say. You did it better.

 

[Buckle-meister]

IMO two dedicated systems is probably required for optimum enjoyment of both mediums.

That's the plan!

Regards

 

[WmAx]

Here, let me throw this in for you to chew. The higher the inductance of the voice-coil, the longer it will take for the tranducer to start to move when a signal is recieved.

AND the greater the group delay, the more delayed the bass will sound.

The inductance, in the capacity that you are referring, is acting as a low pass filter. The effect on transient response is directly calculatable as a minimum phase system, just like with any other standard analog filter. You have to use a low pass filter of some sort on any woofer or midrange, so in this respect, the inductance does not have any appreciable consideration unless it is causing loss of amplitude in a bandwidth which you need to you use the transducer. The considerations of inductance are better appropriated to other factors other than simple frequlency response, and are beyond the scope of this particular discussion.

As for group delay, the one of concern in a woofer, for example, has little to do with it's in inherant inductance, but with the bass alignment used. The group delay in the high frequency rolloff area, again, is homologous to a crossover that is low passing as far as effect on group delay. The effect on audibility of a specific threshold of group delay is another matter entirely, and it's not as straightforward as saying X amount of delay will sound such way compared to Y amount of group delay unless you are referencing this with established perceptual research that allows a somewhat reliable correlation. Even then, room acoustic problems will are far more likely to surpass ones inherant of the bass alignment.

-Chris

 

[WmAx]

I will, however, question the proposition that mass does not affect transient response.

With the same motor, the heavier cone will be slower to start. Now, if you increase the cone mass AND increase the motor capabilities accordingly, then I'd agree. Just because a driver is more massive doesn't necessarily mean that is has poorer transient response.

Adding mass will have two effects on a real transducer. Assuming that you take the same exact transducer, only changing mass, it will change (1) Fs of the system[which will in effect alter the low frequency performance] and (2) it will reduce the efficiency. To say the heavier mass is slower would only be technically accurate so far as comparing absolute velocity of the cones, since you are feeding equal energy to both the heavy and original cone, this is not an equal/fair comparison. This is the same as saying that your speaker is faster when you play it higher volume levels. [The maximum velocity will be increased to achieve X frequency at higher amplitude levels since the transducer will have to move at longer excursion/incursion within the same time].

-Chris

 

[bpape]

Chris,

My point was that simply stating that the mass of the cone has nothing to do with transient response was incorrect without considering the entire transducer and all of the parameters. It is also incorrect to assume that just because a cone is more massive, that it will be slower or a lighter one will be faster.

To take it to the extreme, let's compare it to a car (not an exact comparison but you get the idea).

If you have 2 cars - identical. Can they both do 60MPH? Yes. Will they both accellerate the same (discounting track conditions, driver, etc.)? Yes.

Now, add 4 people to one of the cars. Will it still do 60 MPH? Yes. Will it still get there as fast as it did before? No. Why? More mass with no change in motor capability. It's simple Force = Mass * Acceleration. If you want to accelerate at a certain rate, for a certain mass, you need a certain force. Change the mass and don't change the force, acceleration decreases. Increase the mass AND increase the force accordingly and the same acceleration can be achieved.

Once it gets going, even the smaller motor can keep it moving. Same with a transducer. Take 2 identical drivers and put an accelerometer on them. Double the mass on one of them and measure how long it takes between the time the signal is applied to the terminals until the speaker reaches it's intended excursion for the frequency and amplitued applied. They won't be the same for the original and the one with double the mass.

 

[WmAx]

Chris,



If you have 2 cars - identical. Can they both do 60MPH? Yes. Will they both accellerate the same (discounting track conditions, driver, etc.)? Yes.

Now, add 4 people to one of the cars. Will it still do 60 MPH? Yes. Will it still get there as fast as it did before? No. Why? More mass with no change in motor capability. It's simple Force = Mass * Acceleration.

A car analogy does not seem appropriate in the capacity presented. To use that analogy in a technically correct manner, it must be correlated with my prior statement about absolute velocity[which basicly equates to the efficiency], since this is what it relates to in this subject.

Once it gets going, even the smaller motor can keep it moving. Same with a transducer. Take 2 identical drivers and put an accelerometer on them. Double the mass on one of them and measure how long it takes between the time the signal is applied to the terminals until the speaker reaches it's intended excursion for the frequency and amplitued applied. They won't be the same for the original and the one with double the mass.

The heavier mass will never reach the same excursion/incursion if the same input signal power level is applied to both cases. However, both will react identically and respond to the sine wave input stimulus identically with respect to time, so long as you are measuring at a frequency where the mass difference has not affected frequency response[which would result in a different phase response between the two, invalidating the measurement]. The main relevant difference between the two will be simply be efficiency.

-Chris

 

[bpape]

You appear to be agreeing with me. You are saying that the heavier one will never reach the same excursion with the same power applied. I agree. However, WHY is what is important. Why doesn't it? Because it is significantly behind IN TIME that before it reaches that excursion, the waveform changes phase and tries to pull it back the other direction - thereby stopping it from reaching full excursion. Behind in time starting, lower in amplitude. Call it slow, call it muddy, call it poor transient response - whatever - increasing mass DOES change how the driver reacts - all other things being equal.


Force = Mass * Acceleration is not something you can ignore whether it be cars, transducers, bullets, etc. If mass is increased and force is static, acceleration (time to reach a speed - or in this case max excursion) MUST change.

 

[WmAx]

You appear to be agreeing with me. You are saying that the heavier one will never reach the same excursion with the same power applied. I agree. However, WHY is what is important. Why doesn't it? Because it is significantly behind IN TIME that before it reaches that excursion,

No, it's not behind in time, it's behind in amplitude. Therefor velocity is changed since frequency is fixed. The effect is homologous to changing the power input level to the transducer: the same phase of the sinewave will be reached at the same point in time on both examples, providing that one heeds my warning about frequency response due to Fs changes, and avoid a misinterpretation due to this variable.

-Chris

 

[mulester7]

...IMO HT isn't nearly as demanding from an "audiophile" POV...You need loud...you need directional cues...you need LFE...accuracy is not paramount.

Laser-totin', mechanical lizards don't quite require the subtleties of a string quartet. IMO two dedicated systems is probably required for optimum enjoyment of both mediums. Failing at that, I would opt for the best reproduction for audio. jimHJJ(...TTFN...)

......hmmmmm.....