$600 MTM Horizontally Oriented Measurements
This is one beautiful speaker. Naturally, we wanted to look at higher-end
designs and see to what degree higher quality drivers improve the overall
response versus what if any limitations these more expensive speakers have with
wave interference. This traditional MTM
design has the crossover point at 4 kHz, which is rather high. This unfortunately increases the frequency
areas where the two midrange drivers are interfering with each other, but at
this point we can just assume. Let’s turn
to the charts to see what we get for our hard earned 600 dollars.
In the 1/24 octave chart below you can see some significant wave interference, ranging from +8 dB additive to -10 dB of cancellation. The frequency range where the two midrange drivers would be interfering with each other is highlighted by the yellow bracket. The variation in this range is where we will also be scoring the speaker and comparing against other configurations.
In the 1/6 octave chart below, you can see that the interference between the two midrange drivers is audible. In the upper midrange we can see over -6 dB of cancellation and almost 4 dB of wave reinforcement. You can also see the tweeter has audible off-axis attenuation, but it’s important to emphasize that these tests only reflect variation from the on-axis response and how well we can avoid wave interference. This speaker series has a wonderfully musical sound quality, and I’d take rolled-off beautiful over well-dispersed junk any day.
When the variation of the frequency is calculated at various angles, the average standard deviation of this MTM speaker, from 80 Hz to 4 kHz is 1.62. It’s a beautiful and musical speaker, but the off-axis response of the midrange drivers is mediocre. In this design, the midrange drivers reproduce over five octaves compared to the tweeter’s two, so let’s see if we can improve things by rotating it.
Recent Forum Posts:
irish;637493
Thanks for the recommendations. The Beta 360 would be too large for my application although it does look nice. The KEF Q series, iQ60c, looks like it might work pretty well as it's less than 7" tall. The speaker cabinet design is a bit different but that isn't a breaking point. How do co-axials differ from in sound or performance from a more "traditional" design where the speakers are seperate?
If more speakers had a wider bandwidth, then there would be no crossovers and multiple speakers. Multiple speakers are a workaround for a problem, not an inherent advantage.
The point of a coaxial speaker is to keep the sound coherent. What would be ideal is to have a bass/mid cone that crossed over to the tweeter, 4 kHz, then you would avoid a crossover in the speech discrimination band. However no such animal exists at present and crossover to the tweeter in current units is in the neighborhood of 3 kHz.
In a coaxial, the cone of the woofer acts as a wave guide to the tweeter. Things a re designed such that there is usually time coherence. However because a first order crossover is just about never possible, there are phase anomalies at crossover, just like any other speaker. There is symmetrical lobing and therefore the vertical and horizontal axis response is identical. The coverage is therefore conical.
As far as drivers to choose from the most well known are KEF and Tannoy. Thiel also has a coaxial center. Pioneer also have one in their range.
However, after having auditioned KEF recently the SEAS driver is in my view far superior.
You can buy a LOKI kit [madisound.com] that is very good value.
I use these drivers in my center speaker. The tweeter is used only in the lower driver, the upper one is an active fill driver and the tweeter not connected.
In this TL, I could not be more happy with it.
lsiberian;637476
For If you are interested in a coaxial accessories4less sells KEF speakers for a pretty cheap clip. Still you'd have to like their other offering. I think the best horizontal center I've heard in the budget range is the Beta 360 treated with rockwool and peel-n-seal
Thanks for the recommendations. The Beta 360 would be too large for my application although it does look nice. The KEF Q series, iQ60c, looks like it might work pretty well as it's less than 7" tall. The speaker cabinet design is a bit different but that isn't a breaking point. How do co-axials differ from in sound or performance from a more "traditional" design where the speakers are seperate?
irish;637446
Thanks for your response! I was pretty sure that was the case but I may have no choice due to my set up. It's a living room/HT set up and acoustically won't be great but it's what we have. I'm still learning and have no idea what the bolded words mean. If I understand correctly when a center is horizontal the tweeter needs to be raised vertically so that it's not in line with the mids...
The stand I have is like this one http://www.avsforum.com/avs-vb/showpost.php?p=15604297&postcount=105 [avsforum.com] so there isn't room a for a center due to the units being pushed together. I'm also size limited due to using a plasma on it's stand with a 7" clearance from base to screen so bookshelf speakers won't fit.
The best fit from quality mfgs that I've found would be the Def Techs or Paradigm CC-190 which does have vertically aligned tweeters http://paradigm.com/en/paradigm/speaker_only-specification-6-1-3-4.paradigm [paradigm.com]. Would that be a better option that the Mythos?
Thanks a bunch for helping me out!
These might work too but they're aligned as well http://paradigm.com/en/reference/speaker_only-specification-65-1-3-20.paradigm [paradigm.com]
For If you are interested in a coaxial accessories4less sells KEF speakers for a pretty cheap clip. Still you'd have to like their other offering. I think the best horizontal center I've heard in the budget range is the Beta 360 treated with rockwool and peel-n-seal
irish;637446
Thanks for your response! I was pretty sure that was the case but I may have no choice due to my set up. It's a living room/HT set up and acoustically won't be great but it's what we have. I'm still learning and have no idea what the bolded words mean. If I understand correctly when a center is horizontal the tweeter needs to be raised vertically so that it's not in line with the mids...
The stand I have is like this one http://www.avsforum.com/avs-vb/showpost.php?p=15604297&postcount=105 [avsforum.com] so there isn't room a for a center due to the units being pushed together. I'm also size limited due to using a plasma on it's stand with a 7" clearance from base to screen so bookshelf speakers won't fit.
The best fit from quality mfgs that I've found would be the Def Techs or Paradigm CC-190 which does have vertically aligned tweeters http://paradigm.com/en/paradigm/speaker_only-specification-6-1-3-4.paradigm [paradigm.com]. Would that be a better option that the Mythos?
Thanks a bunch for helping me out!
These might work too but they're aligned as well http://paradigm.com/en/reference/speaker_only-specification-65-1-3-20.paradigm [paradigm.com]
The paradigm C190 is on the right lines, but I think you would have to go with an all Paradigm system, as they have a definite voicing about them, that I did not care for when I auditioned them, at least the Studio 100s
Thanks for your response! I was pretty sure that was the case but I may have no choice due to my set up. It's a living room/HT set up and acoustically won't be great but it's what we have. I'm still learning and have no idea what the bolded words mean. If I understand correctly when a center is horizontal the tweeter needs to be raised vertically so that it's not in line with the mids...
The stand I have is like this one http://www.avsforum.com/avs-vb/showpost.php?p=15604297&postcount=105 [avsforum.com] so there isn't room a for a center due to the units being pushed together. I'm also size limited due to using a plasma on it's stand with a 7" clearance from base to screen so bookshelf speakers won't fit.
The best fit from quality mfgs that I've found would be the Def Techs or Paradigm CC-190 which does have vertically aligned tweeters http://paradigm.com/en/paradigm/speaker_only-specification-6-1-3-4.paradigm [paradigm.com]. Would that be a better option that the Mythos?
Thanks a bunch for helping me out!
These might work too but they're aligned as well http://paradigm.com/en/reference/speaker_only-specification-65-1-3-20.paradigm [paradigm.com]
