As mid range drivers are two smaller (18 cm) drivers preferred over one larger one (22 cm).
The question is; what are the major advantages in both configurations. I was thinking that the two drivers would afford a wider frequency range.
These would be in a 3 way system and they would cover aprox. 250 to 3000 hertz. I am hoping for a good sounding diy system with a budget for drivers of about 1000 euro.
Thanks;
Tmac
The question is; what are the major advantages in both configurations. I was thinking that the two drivers would afford a wider frequency range.
These would be in a 3 way system and they would cover aprox. 250 to 3000 hertz. I am hoping for a good sounding diy system with a budget for drivers of about 1000 euro.
Thanks;
Tmac
yeah, 2 drivers will be better for that freqency range, for one simple reason: cone breakup.
As the frequency of the sound increases, the ability of the cone material of a driver to remain rigid decreases; once you get past a certain point, the cone actually flexes enough to cause a change in the sound. This is called "cone breakup", and as cone diameter increases, the frequency at which it starts, decreases.
The smaller drivers won't get you as much bass extension, but they will get you much flatter and better midrange response in the range you're seeking, and you'll probably notice more the breakup nodes in the midrange, than you would the few hz of bass that will be a couple of dB's quieter.
You can always go with smaller drivers with lower Fs and more Xmax, lower efficiency and high power handling (think car woofers) and get more bass extension, but usually this approach will not give you the same finesse or balance, and will frequently leave you with drivers that are made of chromed aluminium stamped with "50,000 WATTS OF MONDO BASS POWER WHUMP WHUMP WHUMP" or something equally... low-class.
Sorry. My brother in law has several systems like that, and it's rather spoiled my taste for such things.
As the frequency of the sound increases, the ability of the cone material of a driver to remain rigid decreases; once you get past a certain point, the cone actually flexes enough to cause a change in the sound. This is called "cone breakup", and as cone diameter increases, the frequency at which it starts, decreases.
The smaller drivers won't get you as much bass extension, but they will get you much flatter and better midrange response in the range you're seeking, and you'll probably notice more the breakup nodes in the midrange, than you would the few hz of bass that will be a couple of dB's quieter.
You can always go with smaller drivers with lower Fs and more Xmax, lower efficiency and high power handling (think car woofers) and get more bass extension, but usually this approach will not give you the same finesse or balance, and will frequently leave you with drivers that are made of chromed aluminium stamped with "50,000 WATTS OF MONDO BASS POWER WHUMP WHUMP WHUMP" or something equally... low-class.
Sorry. My brother in law has several systems like that, and it's rather spoiled my taste for such things.
Nappylady:
These are very good reasons to use two mid range drivers.
Is the sound dispersion also better with 2 smaller drivers?
Tmac
These are very good reasons to use two mid range drivers.
Is the sound dispersion also better with 2 smaller drivers?
Tmac
I'm not sure at all, and it would definitely depend on how you mount them. The traditional mounting (one above the other) allows your head (listening position) to be farther up or down without as many artifacts. Mounting them side by side would probably give the same effect from side to side, but I'm not sure if this is really beneficial unless you're designing a home theatre setup and you plan on having the whole family listen at the same time.
In short, someone who actually knows should answer 'cause I'm just shooting in the dark. 😀
In short, someone who actually knows should answer 'cause I'm just shooting in the dark. 😀
For the frequency range of 250 - 3000Hz a single 5" or 6" driver would be the best choice unless there are some extenuating circumstance such as:
1. Need to handle a large amount of power via a larger voice coil.
2. Need an increase in output by paralleling 2 drivers.
3. Desire to use a second driver to make up for diffraction loss.
1. Need to handle a large amount of power via a larger voice coil.
2. Need an increase in output by paralleling 2 drivers.
3. Desire to use a second driver to make up for diffraction loss.
I agree with Bill on this...
By using more than one driver you might get into problems with comb effects, where there is cancellation and addition of certain frequencies due to the fact that both drivers are radiating from a different point source, introducing timing issues between the drivers. If you do want to use multiple drivers, make sure they are as small as possible, and spaced as close together as possible to avoid this.
For the frequency range you want to cover, I would use the smallest single speaker that meets your needs for efficiency and power handling. If you can't accomplish that with one driver, then maybe you could go with 2.
By using more than one driver you might get into problems with comb effects, where there is cancellation and addition of certain frequencies due to the fact that both drivers are radiating from a different point source, introducing timing issues between the drivers. If you do want to use multiple drivers, make sure they are as small as possible, and spaced as close together as possible to avoid this.
For the frequency range you want to cover, I would use the smallest single speaker that meets your needs for efficiency and power handling. If you can't accomplish that with one driver, then maybe you could go with 2.
There are two major benefits of using 2 mid-bass drivers in an MTM arrangement that have been touched on:
Much more uniform vertical polar response around the XO frequency. This means that the frequency response is much more uniform with changes in height of the listener relative to the speaker. ie You won't get big changes in sound around the XO frequency if you stand up or sit on the floor.
Speakers with a single mid-bass driver matched to a tweeter can suffer from fairly severe vertical lobing around the XO frequency which means that (like me) you may find you have to sit on the floor for the best sound.
6dB increase in overall voltage sensitivity, which can be useful if you are able to match it with a high sensitivity tweeter or if you are biamping.
Mick
Much more uniform vertical polar response around the XO frequency. This means that the frequency response is much more uniform with changes in height of the listener relative to the speaker. ie You won't get big changes in sound around the XO frequency if you stand up or sit on the floor.
Speakers with a single mid-bass driver matched to a tweeter can suffer from fairly severe vertical lobing around the XO frequency which means that (like me) you may find you have to sit on the floor for the best sound.
6dB increase in overall voltage sensitivity, which can be useful if you are able to match it with a high sensitivity tweeter or if you are biamping.
Mick
Thanks for all of the helpful information:
It seems that there are good reasons for both arrangements.
My intention is to but these into a t-line configuration and I listen to mostly classical music. I also move around a lot when I listen. May even dance; we have the room.
Does this make a difference?
Tmac
It seems that there are good reasons for both arrangements.
My intention is to but these into a t-line configuration and I listen to mostly classical music. I also move around a lot when I listen. May even dance; we have the room.
Does this make a difference?
Tmac
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