Home theater speaker setup theory.

[jlindsey86]

We all know that it is important that the speakers in a home theater all be timbre matched to achieve the best results. After some thinking I thought I would post some questions I have about the best way to set up a HT to achieve optimal sound quality.

Isn't it important that all speakers be of the same impedance?

To achieve the most balanced sound, would it be safe to assume that all the speakers should have the same drivers?

Also I feel as though the sensitivity of each speaker should be rated the same. Otherwise wouldnt the more sensitive speaker have a more forward presentation than the others?

What got me thinking about this was seeing speaker systems offered in packages. Many times the sensitivity rating for the center, fronts, and surrounds were all different. In some cases so was the impedance. Such as the fronts being 4ohm and the others 8ohm. I guess what I am getting to is that to achieve maximum results would it be best to have the center, fronts, and surround to be the exact same speaker? This is only a thought that occured to me. If I am off base here let me know.

 

[captaincool]

Well I am no expert, but wouldn't your calibration account for any difference contained in your speakers?

 

[Sheep]

Isn't it important that all speakers be of the same impedance?

Yes, except for the subwoofer. Usually, speakers of the same timber have the same impedance.

To achieve the most balanced sound, would it be safe to assume that all the speakers should have the same drivers?

Yes, this is what is meant by timber matching; Same drivers, Same Crossovers (to a degree), and same construction quality.

Also I feel as though the sensitivity of each speaker should be rated the same. Otherwise wouldnt the more sensitive speaker have a more forward presentation than the others?

Level matching fixes this.

SheepStar

 

[j_garcia]

Usually, speakers of the same timber have the same impedance.

That is not true. Speakers can have the same drivers and same x-over design but have different impedances. Example would be a 2way bookshelf vs a center that has the same drivers, only there is an additional midbass in the center - the center is 8 Ohms while the bookshelf is 4 Ohms - they still have the same timbre.

Speaker positioning is also a large factor in how loud the percieved sound is at the listening position, so sensitivity is important, but it is by no means the deciding factor. That is the entire point of calibration as captaincool and sheep noted; regardless of the other factors, calibration should get the speakers to the same level at the listening position.

 

[jcPanny]

I agree

It is common for floorstanders or center channels to have a lower or different impedence then the timber matched bookshelf speaker. Some people also use an outboard amp for the mains and receiver for the remaining channels. Neither of these effect the timber matching of the speakers which is more dependant on driver size and type and crossover design.

 

[Pyrrho]

We all know that it is important that the speakers in a home theater all be timbre matched to achieve the best results. After some thinking I thought I would post some questions I have about the best way to set up a HT to achieve optimal sound quality.

Isn't it important that all speakers be of the same impedance?

No. All that matters is that the speakers be "timber matched" and the amplifier is capable of dealing with all of the impedances, whatever they are. However, the very best way to have absolute timber matching is to use exactly the same speakers in the different positions one wants to be timber matched. This is particularly of interest for the front three speakers. Most people, however, use a different speaker for the center channel.

To achieve the most balanced sound, would it be safe to assume that all the speakers should have the same drivers?

In theory, all that matters is that they reproduce the same frequencies in the same way relative to each other. In practice, you are absolutely correct. It is difficult (if not impossible) to achieve exactly the same sound across the entire frequency spectrum with different drivers.

Of course, if you simply mean overall channel balance (rather than timber matching), then it does not matter at all, as one should properly calibrate the system in any case, as room acoustics and positioning of speakers will affect the volume of a speaker as perceived from the listening position.

Also I feel as though the sensitivity of each speaker should be rated the same. Otherwise wouldnt the more sensitive speaker have a more forward presentation than the others?

No. One needs to properly calibrate the system which will take care of such things. And, as mentioned above, one should properly calibrate the system in any case, as room acoustics and positioning of speakers will affect the volume of a speaker as perceived from the listening position.

What got me thinking about this was seeing speaker systems offered in packages. Many times the sensitivity rating for the center, fronts, and surrounds were all different. In some cases so was the impedance. Such as the fronts being 4ohm and the others 8ohm. I guess what I am getting to is that to achieve maximum results would it be best to have the center, fronts, and surround to be the exact same speaker? This is only a thought that occured to me. If I am off base here let me know.

Certainly, for the best sound, if the speakers will fit in one's home theatre, the front three speakers should be identical. However, with surrounds, there is reason to think that dipole speakers may be better, though people have debated the merits of direct versus dipole speakers elsewhere, and I have no wish to launch into a lengthy discussion of which might be better. I will add, though, that both can be good, and I have used both at different times. In my opinion, if all else is equal, usually dipole speakers are better, but I am currently using identical speakers all around. (I cannot get dipole speakers that are voice matched to my front speakers, which are the best speakers I have ever owned).

 

[abboudc]

We all know that it is important that the speakers in a home theater all be timbre matched to achieve the best results. After some thinking I thought I would post some questions I have about the best way to set up a HT to achieve optimal sound quality.

Isn't it important that all speakers be of the same impedance?

No. Only that they're voice matched.

To achieve the most balanced sound, would it be safe to assume that all the speakers should have the same drivers?

No. That's the easiest way to voice match speakers, but not the only way.

Isn't it important that all speakers be of the same impedance?

No. Only that they're voice matched.

Also I feel as though the sensitivity of each speaker should be rated the same. Otherwise wouldnt the more sensitive speaker have a more forward presentation than the others?

No. There are too many other variables -- distance from speaker to listener, power output of front vs. rear, calibration, etc. Proper setup of your equipment can overcome all of these things.

What got me thinking about this was seeing speaker systems offered in packages. Many times the sensitivity rating for the center, fronts, and surrounds were all different. In some cases so was the impedance. Such as the fronts being 4ohm and the others 8ohm. I guess what I am getting to is that to achieve maximum results would it be best to have the center, fronts, and surround to be the exact same speaker? This is only a thought that occured to me. If I am off base here let me know.

There shouldn't be huge sensitivity gaps in a packaged set. Impedance mismatches by themselves aren't a problem, it's only a problem if your amplifier is not capable of driving the load effectively on the lower impedance channels. Some people prefer all the same speaker all around, but most people have smaller speakers in the rear.