SO, WHAT'S IT LIKE?
The new sub (cabinet) next to a REL t7i:
Hello folks. Sorry it's taken me a while to return to this build thread. Life has been busy and I've had some interest from people who would like some bespoke speakers and a sub! 😀 This is great news, as it means more time in the workshop.
BREAK IN:
The first job with the new sub was to break it in! The driver (and passive radiator) surrounds are very stiff to begin with and require a fair bit of work to loosen them up. Once broken in the sub will go deeper and be noticeably faster and more dynamic.
You can just use the sub normally and it will (eventually) break in, however, this can take many months and the setup/integration will need to be updated as the sub breaks in.
I did most of the sub break in over 2 days - I got a bassy playlist together and left it on repeat. It's worth using a few different tracks so you can play bass over a range of frequencies from 30-100Hz. The sub was turned up moderately loud - not maximum, but much louder than normal listening levels. It was quite unpleasant to be in the same room, and reasonably unpleasant to be in the house during break in. We (the family) all went out to escape the thunderous vibrations.
After 2 days (about 12 hours) it was sounding much louder, deeper and faster.
INTEGRATION AND SETUP:
This is the most important phase with a sub and actually a real challenge to get right! A badly integrated sub is not a good sub - it will make itself obvious and generally make the sound more muddy and boomy. A well setup sub, however, will add depth, detail and texture to the bass. More importantly, a well setup sub will add depth and warmth to the mid and treble and give a lovely depth and spacious quality to the soundstage.
To start, I placed the sub directly in between the two speakers, about 6" in front of the wall. I didn't actually try it on either side, as it was a bit of squeeze. It frankly looked pretty cool with pride of place in the centre too 😎😀.
This sub is slightly different to a standard REL (for example) as the Hypex module allows a detailed tuning of the high pass roll off slope and frequency. I won't go into the detail of the Hypex software here as it is pretty in depth and further detail can be found on the Hypex website.
I started with phase, but struggled a little as I have no accurate way to measure the effect of adjustments. I first increased the gain (over what is normal) and set the crossover too high - this gave a good overlap with the speakers. I then tried the phase at 0 and 180 degrees. One obviously made the bass quieter, so was too out of phase with the speakers (not good), the other option was louder, so I settled on this for now. I plan to buy measurement kit soon so will dial in the phase more then.
The (FA251) plate amp has three quick access presets - these can be accessed on the unit or via a (usb connected) laptop. My speakers start to roll off in the 35-40Hz region. I began with three presets at 30Hz, 40Hz and 50Hz. With music playing I sat in the hot seat and flicked between the different sub roll offs. It soon became evident that 50Hz was too high - the bass was overblown (even with lower gain) and flabby. 40Hz sounded pretty good, but maybe still a little too much overlap - bass drums sounded slightly too full and the double bass had lost a little tightness compared to 30Hz.
I next changed the 3 presets to 30, 35 and 40Hz. They all sounded reasonable, but 40 was definitely too much. The next 3 presets were 30, 32.5 and 35Hz. I was getting close now, so spent the next few days listening to lots of music and occasionally flicking between the options. I sometimes tweaked the gain by a few dB to see what difference that made. After a week or two, I settled on the crossover at 30Hz with perhaps a slight lift in gain compared to 35Hz. This gave a great balance of depth, speed and tightness. I sometimes detected a little bloom at 32 and 35Hz.
HOW DOES IT PERFORM?
After a week or two I felt that everything had fallen into place and sub was integrated well and sounding good. How did it sound compared to 2 x REL t7i's??? Much, much better! Which is very impressive since it is a single sub vs a stereo pair retailing at £1700 in total. Where to start? Firstly, it goes much deeper - the RELs added a tiny bit to the bottom end of my floorstanders, but this sub goes noticeably deeper and adds more weight. It's definitely not 'flabby' or boomy weight - it portrayed a much more realistic, tighter and weightier bass. Not more bass, but more 'real' bass. Double bass, bass guitar and kick drums just sound more fleshed out (in a tight way). This new sub is definitely faster and more dynamic than the RELs, and the RELs were no slouches.
The bass was a great improvement, but it wasn't necessarily the greatest improvement… the soundstage was noticeably deeper, wider and more realistic. Mid range and treble were softened in a good way - richer and fuller without any loss in detail. Vocals were somehow warmer and with more depth too. It almost seems impossible that the mid, treble and soundstage would change so much. It was immediately verifiable though - I could sit in my listening position and (via the laptop) switch the sub off. This was a strange sensation as you could hear (and almost see) the soundstage collapse and the general tone would become slighter harder and more edgy through the mid and treble. When switching the sub off the bass would change, but not always how you'd expect… There wouldn't be 'less' bass with the sub off, but there would be a noticeable reduction in bass quality - the kick drum, bass guitar and double bass would have less depth, weight and a loss in realism.
Another big difference was with mostly bass free music… The sub shouldn't make a difference but it does - there was still a noticeable improvement in soudstage depth and instrument separation. Somehow the (extra frequency) depth would add more richness, tone and body to all instruments, not just deeper bass instruments. I believe the sub is adding more spatial and ambient cues - these are often very deep room modes and echoes and add a wonderful 'realness' and natural quality to the sound. It really shows how the sub 30Hz region is important to playback of a lot of music. Many people will argue that the 30Hz isn't that important in music… I would beg to differ and ask them to perhaps try and listen to a (well setup) sub. In particular, sit and listen to the music change (for the worse IMHO) when the sub is switched off. Everyone I demo the sub to (including sub doubters) are amazed at the change when (the sub is turned off) the music losses a touch of realism and collapses down.
So there you have it folks. I love my sub and wouldn't be without it.
THANKS SO MUCH FOR FOLLOWING THIS BUILD JOURNEY. 😀🙏
My speaker build is continuing on this forun and I shall be starting a small (standmount) build thread soon.
