Soffit Mounting Atc scm 100a's?

Bryan · Post by **Bryan** » Sat Jan 17, 2004 12:50 pm

Hi all

Would it be a good idea to Soffit Mount a pair of Atc scm 100a's?

My room is 21' long and 12' wide 8' high.

@ the momemt there on stands and im about 4/5' away.

I know there capable of very high spl's but are the designed to be soffited?

Im going to do an analysis with smaartlive tomorrow and will post the results.

cheers
bryan

barefoot · Post by **barefoot** » Tue Jan 20, 2004 10:44 am

Wow, ATC..... faaancccy!

Soffit mounting is almost always a good idea - as long as the speakers are front ported like the SCM100's are. I'm not 100% sure if they have EQ settings specifically for soffit mounting. If not, you might need something like my SC2 Loudspeaker Controller.

Thomas

Bryan · Post by **Bryan** » Wed Jan 21, 2004 5:46 am

Hi
thanks for the response.
Yea they sound real nice(or not as the case may be

I got an unbelivable deal on them, I couldnt belive it when a guy about an hours drive had them in the paper.

He had the in his garage, used to be in his sitting room but he bought a surround set up .

any way there is bass and treble on the back but dunno what frequency,q or cut it is???

Do you know can the amps come off the back??

Also what distance/hight is reccomended for a speaker this size?

cheers
bryan

barefoot · Post by **barefoot** » Thu Jan 22, 2004 3:16 am

Here is the word from ATC.

Hi Thomas,

The 100's can be used free standing or soffit mounted but for soffit mounted use the speakers will require re-calibration due to the low frequency gain achieved by this type of positioning.
The crossover frequencies are at 380Hz and 3.5kHz.

Regards,

Ben Lilly
R&D Engineer

This is just as I suspected. The SCM100 bass adjustment only provides gain, not cut. So, you will either need to send them out for "recalibration", or you can use your own low shelf filter.

Higher crossover points yield better power handling, but provide a smaller "sweet spot". The 3.5kHz crossover indicates a medium to far listening position - I would recommend at least 6 feet. Tweeter at ear level is the optimal height. But if you must mount them higher to clear the meter bridge or near fields, then tilt them downward to keep the tweeter axis pointing towards the listening position.

Thomas

Bryan · Post by **Bryan** » Thu Jan 22, 2004 10:44 pm

Hi again,

Just double checked my atc's and they actually
only have high and mid boost/cut and no bass at all.
weird

Anyway my room is built now and i was just thinking i
dont really want to go knocking holes again, i prefer making
music

I have tweeters at ear level but its just there so big that puts the
bass drivers cone level with my desk.
so half the speaker is below the desk

surely this my be causing reflections or are bass frequencys too strong to
for this??

thanks for the help.

bryan

barefoot · Post by **barefoot** » Fri Jan 23, 2004 2:31 pm

Bryan,

Yeah, having the woofer below desk level isn't so great. With that 380Hz crossover the woofer is still going to be producing noticeable output beyond 500Hz. These wavelengths are certainly short enough to cause reflection problems. I don't see anything wrong with turning the speakers upside-down, as long as you have room above.

Also, I don't know if you've looked at my 2D Wall Bounce Calculator yet, but I strongly recommend it. When you see the serious response issues associated with front and side wall reflections you might conclude that breaking out the old hammer and building those soffits isn't such a bad idea after all. Your SCM100s are truly great speakers and it would be a shame to waste their potential. Putting them in a bad room situation is sort of like parking your Bentley under a pigeon roost!

Thomas