MTM or Single Mid configuration

[Radugazon]

And report please, that can be an interesting subject, even if it's just about listening appreciations. My 2 cents : with an electrical LR IV @ 3800, it's possible that you will end with something more steeper.

 

[domtweaker]

Very possible but looks like others have used it at that point

Marchand x over allows me to swap cards in minutes and change

so we ll see

 

[tinitus]

I will do that

3800 hz 24dB LR

I will build two front baffles one for single and other for double ATC s

you need to be very skilled and experience to do 24db
12db might sound better
depends on several other choises
but I guess low pass on ATC mid needs to be relative high anyway
and thus 12db might be ok
but you need a pretty good 12" woofer

 

[domtweaker]

400 and 3800 hz


woofs will be 15 " volts . I think they will match fairly good .

I have heard this before in a nice system

 

[Radugazon]

]hello tinitus...as an user (dumb hehe) of the formula, I can say that two drivers of this kind if crossed just over the distorsion zone can cope with a lot of power and provide a very detailed sound. But as said in the link, EQ will probably be required. This means also a good measuring stuff.

An externally hosted image should be here but it was not working when we last tested it.

maybe 400 is a little bit low

 

[dsrviola]

There are some interesting responses to your query on this thread. A TM is not necessarily going to sound better than an MTM. It will sound different. Assuming that your drivers are NOT going to benefit significantly from the reduction of excursion and increase in power handling by running two drivers instead of one, there are other benefits that you may find appealing. For me, I find that the lobing pattern of most TM's to be unnatural sound. The big suckout in the crossover region of the off axis response is usually above the tweeter. I not only find it annoying to hear response anomaly whenever I'm standing up or walking around, but I find that it has a greater negative impact (even in the sweet spot) on the overall balance of the sound than an MT (midrange on top). The nice thing about an MTM (in this case) is that, while you have more lobing than a TM (or MT), the lobing is symmetrical vertically. I find it's easier to get a smooth power response than a TM (or MT). I can't say that my experience lines up with tinitus' experience at all. I think that just has more to do with what crossover you go with. I do agree that a single driver arrangement can sound more "pure" than two, but for me the benefits of an MTM outweigh the potential loss of "purity."

Good luck!

 

[domtweaker]

I think the single unit will do

I may use a mid 10 Volt to go between the 15 and ATC

Its a 4 way Active system so dynamics and eff matching are not that critical

I just like the idea of single point imaging and best of all

I Have another ATC for my other project

I will use a super tweeter on top of the Esotar 330 for ambience

cheers

 

[Bratislav]

I can say that two drivers of this kind if crossed just over the distorsion zone can cope with a lot of power and provide a very detailed sound.

Well, ATC themselves use only one mid and have no issues pushing it well over 120dB/1m


SCM300A SL SPECIFICATIONS

Drivers HF 34mm, Mid 75mm, LF 2 x 375mm
Amplitude Linearity (±2dB) 50Hz-12kHz
Cut-off Frequencies (-6dB, free-standing) 25Hz
Horizontal Dispersion ±80°, Coherent
Vertical Dispersion ±10°, Coherent
Max. Continuous SPL (1 metre) 121dB
Crossover Frequencies 380Hz, 3.5kHz

Note this is a "pro" continuous 121dB (that is, real). Two SM75-150S would definitely be an overkill for domestic application ...

 

[domtweaker]

I think its the overall presentation of the sound that may be better BUT point imaging is better with a single unit