Edifier T5S vs PreSonus Eris Sub 8BT for R2750DB MKII — bass extension, integration and usability.

[Trote]

Building a 2.1 setup for a small room — prioritizing sound quality, soundstage, and precise bass over raw output. Want to expand the low-end and having trouble deciding on a sub.


Current mains: Edifier R2750DB MKII ( 3-way active 7″ woofer, 4.5″ mid-range, 1″ silk dome tweeter , ~45Hz rated, has SUB OUT).

Choosing between two ~$200 subs:

• Edifier T5S: 8" driver, 70W, 35–115Hz, ~150mV input sensitivity, adjustable low-pass, phase switch, RCA only.
• PreSonus Eris Sub 8BT: 8" driver, 50W, 30–200Hz, variable gain (-30/+6dB), variable low-pass (50–130Hz), defeatable 80Hz high-pass on pass-through, polarity switch, TRS+RCA.

Questions:

1. Is R2750DB MKII + T5S (same-brand pairing) a solid choice? I've seen one review mention it lacking in bass, but that's a single data point — anyone with firsthand experience?
2. Does anyone know if the R2750DB MKII's SUB OUT is already crossover-filtered, or full-range?
3. Is 150mV input sensitivity (T5S) fine for a typical DAC line-out, or borderline? There's also a question of whether the sub reliably wakes from standby off that signal level.
4. Anyone run a PreSonus sub off a non-PreSonus main speaker's sub-out? Curious if the Eris Sub 8BT's pass-through stays live during its 40-min standby, or mutes.
5. Any technical reason to expect one sub to have tighter/deeper bass than the other in a sealed nearfield setup, or is it mostly gain-staging/placement?

Appreciate any measured data or firsthand experience.

 

[somebodyelse]

I'm guessing nobody has the first hand experience, so I'll add what I can from other sources. I've not found measurements of the R2750DB MKII plus the documentation on them is less than informative. It would be good to know what source you are using in case DSP in the source is an option.

See this post for link to CTA-2010 results for the T5s (mentioned) and Eris Sub 8BT (not mentioned, but in the same Google sheet). The T5s is capable of higher output across the board so in theory the better option (except at 20Hz - probably a high pass filter to protect it from signal lower than it can safely play - but at 20Hz the Sub 8 has so little output you probably wouldn't hear it anyway). Whether it's better in practice will depend on how well you can match it to the mains and whether you can use PEQ to flatten any peaks. Placement will be the same for either. I'm not sure what you mean about a sealed nearfield setup - both subs are ported. Based on this post Edifier don't offer any PEQ on the T5s although in theory its DSP could do it - perhaps they'll update it at some point, but I wouldn't bet on it. That thread mainly reviews the Aiyima 800X which is in a similar price range. Out of the box it has some significant problems, but if you're the sort of person who's happy messing with ESP32s and voiding warranties they can be mostly fixed and custom PEQ added, which might make it a worthwhile option. I don't think the Sub 8BT has any PEQ either.

Is 150mV input sensitivity (T5S) fine for a typical DAC line-out, or borderline? There's also a question of whether the sub reliably wakes from standby off that signal level.

150mV sensitivity should be more than enough - you'll probably have to turn it down a fair way from the max.

Anyone run a PreSonus sub off a non-PreSonus main speaker's sub-out? Curious if the Eris Sub 8BT's pass-through stays live during its 40-min standby, or mutes.

I don't think it would make any difference - either nothing's playing, in which case it probably doesn't matter whether it's muted, or something's playing, in which case it'll wake up and pass it through. Assuming it works according to the manual anyway...or that when unpowered there won't be enough noise pickup for the mains to wake and hum or buzz.

 

[Thelo80]

T5s measured in my living room with an 85hz LPF. Great bass up to 35 hz.
No problem with the standby off signal.
I wouldn't use it without PEQ (umik -1 + REW +Wiiim Ultra). Wiim roomfit proposed correction was not great, too boomy.

 

[anb890]

Hi, a bit late but I bought both subs a while ago. I ended up returning the Eris and bought another T5s for a desktop 2.2 setup.

Does anyone know if the R2750DB MKII's SUB OUT is already crossover-filtered, or full-range?

Does not matter as both subs have their own low-pass.

Is 150mV input sensitivity (T5S) fine for a typical DAC line-out, or borderline? There's also a question of whether the sub reliably wakes from standby off that signal level.

It is very sensitive as already mentioned. I had to turn it all the way down to the minimum for it to be usable. There are no issues with waking up from standby or prematurely going to sleep and it takes about 3 seconds for it to start playing.

But it has an issue at very low levels; the noise gate will clip the signal which can cause a spotty and distorted sound. This also means that it won't play at all if the signal is low enough. It starts at around -52dB and completely stops playing at -60dB.
I noticed this the most with fast double-bass metal where the rapid kicks often phase-cancel each other; meaning the volume of the "thump" changing all the time. Makes the kicks sound very random and inconsistent. The distortion is minor only noticeable if you mute the mains. Zero issues at higher volumes.

This doesn't matter unless you like to listen below ~45dB SPL.

The Eris does not have this problem, at least with balanced inputs. Instead it hums, which I assume comes from cheap class A/B amplifier.

Anyone run a PreSonus sub off a non-PreSonus main speaker's sub-out? Curious if the Eris Sub 8BT's pass-through stays live during its 40-min standby, or mutes.

The RCA/TRS outputs stop playing if the Eris is inactive. On the T5s the RCA-outs are passive and will pass the signal even if unplugged from power.

Any technical reason to expect one sub to have tighter/deeper bass than the other in a sealed nearfield setup, or is it mostly gain-staging/placement?

The T5s plays noticeably deeper than the Eris. You will likely also have an easier time finding a good spot for thanks to its smaller footprint.

No smoothing or EQ, measured with a UMIK-1. The room dimensions are 470x340x275cm and both subs were corner loaded. The UMIK was at listening position, which is centered along the short axis, 120cm away from the wall, and 110cm above the ground:

Note: this is purely about the extension difference itself. The actual roll-off frequency will be slightly different depending on the room and where you place it. Corner loading is also the best-case scenario for extension but will cause issues. In my case there is a massive 16dB peak at 100hz. I do not recommend doing this unless you can/are willing to use EQ. There is also a cancellation at 28.7hz which shaves off a bit.

In my opinion, the T5s is the superior product all things considered.
It has significantly more peak output at 35hz and below, which aligns with Brent Butterworth's measurements . Plus it is much cheaper, has better build quality, and does not hum.
I don't recommend the Eris over the T5s unless you primarily listen at very low volumes or intend to use the inbuilt high-pass for the outputs. Do note that it is a fixed 2nd order (12dB/oct) 80hz high-pass and not adjustable outside of turning it on and off.