Intro
Contents
We know British ATC mainly from studio speakers. And bookshelfs and floorstanders. Think of the SCM19 V2 which has become a reference at Alpha Audio. What you may not know is that they also manufacture Home Theatre models. The so-called HTS series. We test the HTS40. A large – heavy – on wall loudspeaker.
If you want to build a very serious cinema, you have a lot of choice. Not only in terms of amplification and source, but also in terms of speakers. Almost all major manufacturers have in- and on-wall models. Or in-ceiling, of course. ATC also has a special series for theatre freaks: the HTS line. And that includes three models: HTS7, HTS11 and HTS40. All on-wall.
The advantage of in- and on-wall is that the manufacturer already knows what the placement will be. And they can take that into account in the design. The cabinet, the filters and the units can thus be adjusted for placement against or in the wall. In the end, that should ensure a balanced sound.
This HTS40 of the British ATC is – sort of – the on-wall version of the SCM40. The big brother of the SCM19 that we have been using for a long time. Of course the HTS40 doesn’t have the cabinet capacity of a large floor standing model, but that shouldn’t stand in the way of a tight and deep enough bass, according to the specifications of ATC. It shows a half space radiation measurement running from 32Hz – 22 kHz -6dB. Half space radiation measurements are different from direct measurements in a anechoic room. But it gives an idea. (The SCM40 measures from 48Hz – 22 kHz at -6dB.) You will see that our measurements show something else. Below 100 Hz, not as much happens when we do a ‘free’ measurement (without a time window). That’s not strange considering the size of the HTS40.
Structure
But before we go any further, it might be interesting to look at the construction of the speaker. The ATC HTS40 is a three-way system with the famous ATC midrange dome unit; a 75mm model in this case. Above that we find a 25mm soft dome tweeter. Under the midrange dome is a 164mm woofer. The Crossovers are on 380 Hz and 3500 Hz. These are favorable crossovers, considering the vocal range. So the ATC should perform pretty clean in this area.
The cabinet measures 740 x 380 x 154mm. That gives 43 liters. The SCM40 gives 108 liters. It would measure from 48Hz – 22 kHz at -6dB. It is difficult to beat physics. But anyway: a subwoofer will solve a lot.
