This is a review written by Terry Ellis August 2024.

For my video review please see my YouTube channel link here

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RED is the colour of…

Can you imagine the situation, an audiophile wakes up and decides today is the day to upgrade my subwoofers. They want fast bass, they want powerful bass so they want a real kick ass subwoofer and they want to be coloured red. I bet you have never had that collection of thoughts before but maybe after this review you will.

This is my review, or really talking about my experiences with two REL Acoustics T9X RED subwoofers and straight away there is a problem with this review. If today you went to the REL website to buy the T9X RED, link here you would see they are out of stock. The T9X RED has only been limited edition product. So when REL asked to review a pair of RED this was the first thing I mentioned to them, but they told me don’t panic have a play and see what you think as maybe there will be more limited editions coming in the future, there is an inside scoop for you straight away.

Still a T9X

Yes this is a T9X subwoofer that you are likely already very familiar with, I had one of the first review samples available back in April 2021 and nearly 65000 of you have watched that review video so I know this has been a very popular subwoofer.

I dare there will be some of you reading this that already owns one or two and that is fantastic because this is a great subwoofer for most general use cases. Yes for the same money you can buy much bigger, more powerful subwoofers with bigger drivers that will move a lot more air. You might want that for certain situations, big rooms, high SPL cinema bass for sure. For more “real world” applications, normal sized lounges, apartments I think the T9X hits a nice sweet spot of performance vs physical size vs appearance and that is the perfect Segway into the big RED elephant in the room here.

Nearly every subwoofer I have seen in someones home has been black. A couple of times I have seen white or wood to match the speakers but never once RED. I would never have thought to have a red subwoofer, I would never have chosen a red subwoofer but with two of them sat looking very svelte next to some KEF R11 Meta speakers I love the red I think it looks awesome. Mostly because the T9X is not too big and there are some visual contrasts that break up the strong red colour such as the driver and the carbon REL logo top plate.  I am not as keen on the look of the RED with the grill on but your mileage may vary especially if you have cats or young kids, you might want that driver protected.

Lets start with what’s familiar, it will be the main form factor as this is the same size as a normal T9X subwoofer.  The 300 watt amplifier and amp plate controls on the rear are a standard T9X affair too. This is totally fine because the connections and controls are already familiar, especially if your into a REL wireless connection as that is still here.  I used a wired high level connection as I have REL bass line blue cables plumbed into my room behind the acoustic treatment and this works perfect given where the subs are placed in the room always in the same place give or take.

What is new?

So what is new here apart from the obvious very fancy Italian sports car red paint and the very obvious fancy REL logo top plate that is very nice I have to say.  The big change is to the subwoofers main driver. Not the down firing passive radiator which I am pretty sure is the same as whats used in the standard T9X and again its surprising that there is a logo on the passive radiator that no one ever sees as its underneath but kudos to REL for that attention to detail.

The forward firing main driver on the standard T9X has an aluminium centre cap intended to be a stiff, strong and light centre to the driver hat REL say is critical for its performance.  The main driver in the RED the centre cap has been changed to carbon fibre that REL say shaves 10 grams off the weight giving the overall system a faster response and 1.2db more output.

As the driver change is the this main integral difference of the RED’s design I asked REL to send me one so we could have a look at it and at first it maybe doesn’t look too special. However when you hold the driver in your hands its oddly unbalanced because there is a huge amount of weight in the thick, what appears to be a double magnet system, but there is hardly any weight at the driver end. In fact the driver end is so light the whole thing feels quite bizarre to hold in your hands due to the natural balance.  I now know when REL claim their drivers are very light they are not exaggerating.

I suppose the last new thing to talk about are the different legs. The original T9X I think legs are look very nice in silver and added some understated elegance to the subwoofers appearance and I have no complaints at all about them. However when I compare them to the newly designed  legs of the RED, I think they have an extra touch of class about them and I like the look a little more.

So the RED is shaping up like a mini Carbon special subwoofer and that is very exciting except there are a couple of visual touches missing. I think the side profile of the RED would have looked amazing with the REL S range and above silver handles, they would have really elevated the RED’s look.

One other thing that would have been great is the removal of the four black grommets that hold the grill and instead the use of a magnet system. REL told me a magnet system for a grill is hard for a subwoofer due to the forces that can act upon it, but either way I think a solid colour front to the subwoofer would look better but maybe it is just me being a greedy audiophile who is never satisfied

Bass really matters

Initially REL did come and set the two subwoofers up for me in the room and I understand why, but I am really fond of manufacturers doing this.  I like to do it myself so I get the full experience and because I like to think I know what I am doing by now having setup and calibrated over 150 different systems all over the world. I started the subwoofers setup from scratch and my preferred way of setting up subwoofers  is to use more of them than a lot of people. By this I mean crossing over higher than where the speakers might play down to, creating a double bass situation. This works fantastically well for many technical reasons buy only if the subs are fast enough to keep up with the speakers and you have to position them right for time alignment with the speakers and most importantly each other.

This is where a subwoofer like a T9X has an advantage being pretty compact and not overly heavy you can easily slide them around to help audible lock the bass timing tightly between the sub and speakers and the two subs themselves. I wonder how many of you think about this as part of your setup, because using REL’s high level connection approach you are essentially setting up the subwoofers as an extension to the speaker and that is different to a subwoofers signal going through a DSP with the benefits of time delay controls, so your time delay with high level is a physical position of the subwoofer delay something important to bear in mind.

I started with the REDs sitting just behind the KEF R11 Meta speakers as that spot in this room is usually great, I have measured this room in every position hundreds of times over the years so know generally where is good and not good for subs. It was a great position with just the one RED playing, I integrated the first one super easy in less than 5 minutes and all was well. However when I added the second the bass was hitting my room just a little too much in a specific frequency region which was a good sign of the T9X having a bit more output than I was expecting. I pulled both subs forward to be just in front of the KEF speakers and slightly further away from a room boundary, I changed the phase of each RED and also turned their volume up about 2 clicks each and now there was a great overall bass balance between the speakers and subwoofers and a very even spread of bass from the left to the right of the room where it was impossible to hear what speaker or subwoofer was creating the bass notes.

Remember I has set a higher crossover then you might think you would need with a larger speaker like the KEF R11 Meta, I didn’t measure it but I would guesstimate the crossover was in the 60-70Hz region. This was totally on purpose and now the bass was mostly excellent in the room. However the speakers more I think were still hitting the room a little too heavy in the very deepest bass notes so that is where the EQ function in the Eversolo A6 was a great tool to reduce the bass at 24Hz about 7db, tweak the rest and the overall sound quality I was getting from the system was pretty phenomenal for all the music I played.

I listened to a whole variety of music including hip hop, light drum and bass some dance, various commercial chart topper types through to some jazz and doing the classic subs on and then off test is always the best way to see what the subwoofers are adding or taking away.  The RED’s on effect was about the same for every song with a great example Birds by Domnique Fils-Aime, the KEF on their own do a fantastic job with the layering of that track. The double bass is back right, vocal slightly off centre with more going on as the track progresses. I like this track to sound very big and bold with its bass hitting the room with big tactile bass notes you see being played through your ears, with the notes forming in the room in front of you. The KEF on their own just don’t give you a true full feeling bass with in the room presence,  yes they layer that whole track out fantastically but their bass delivery I think is too play it safe and that track becomes tame from a bass dynamics point of view.  Add the the REL RED’s set up well all of a sudden this track is a lively physical tangible event happening in your room rather than something you sit flat and listen to its now a musical experience. That’s what having an extra amount of really great quality bass does to all music but not all speakers give you that and that’s when subwoofers do become essential.

But how do they sound?

Talking specifically about the bass sound quality of the T9X RED the first thing you notice is its very nimble and light on its feet. You will often hear people say that about REL subwoofers, or you will hear REL say it for sure. With the RED there seems to be a noticeable uptick in the definition of bass notes, where there would normally a bit of bass throb the RED unpacks that throb into separate bass layers. But you don’t listen to it and think the bass is lightning fast, start stop. I would hate that anyway, instead you still get a smooth flowing nice bouncy (pleasing) bass but there is a little bit more bass articulation detail that’s comes through or another way to explain it would be the bass feels a little less congested.

I remember experiencing something similar with the standard T9X and I called it “speaker like bass” and that is still the case with the RED, but I think the RED has a bit more “balls” about it too, so the bass feels a bit more substantial while also digging out a bit more detail articulation than you expect. Its a double whammy of an improvement both welcome in my view. I wonder if its more to do with the recovery speed of the driver because its lighter maybe we can hear the driver recovering quicker, or not hear the drivers memory, or whats called hysteresis but that’s just my best guess.

This is still a T9X, so its still a 300 watt 10 inch subwoofer and because of the laws of physics that kind of subwoofer doesn’t “hit” the room in the same way as larger driver subwoofers can. That means you don’t get as much room weightiness to the bass meaning the bass is not as heavy on you or it doesn’t throb your body as much and it doesn’t wrap around with as much as larger subwoofers with the big room warming pressure feeling. That is something to think about here depending on what you want, are used to or need in your situation. This is important to think about

But I think this also helps the RED to stay fast sounding as its not loading the room with as much pressure that can cause the bass to linger in the room for longer that can causes the congested bass sensation. Its also less likely to upset your neighbours or significant other so it’s a pro and con situation maybe,  and its also something you might never notice if you haven’t lived with big subs, but if you have you will notice some difference here.

However if I am being totally honestI could be happy with a pair of RED’s with the right speakers for music as they just about get the job done in terms of hitting the room while always being very clean and clear sounding always with great bass articulation without ever sounding mechanical, this is great for the higher crossover approach I like. I like this not because I want my teeth to rattle, its for more bass delivery in the critical regions that helps all music sound more pleasing because there is more fullness and warmth to the systems sound, I think a lot of people like this kind of sound based on my travels.

Final Thoughts

Concluding things, do I recommend the RED over the standard T9X given the higher price, around £150 premium, if you could buy them today and I think the question simply boils down to the colour red. Can you live with a red subwoofer because a standard T9X is still a great subwoofer and its black and its cheaper, more so if your buying two of course.

I am the kind of audiophile would  happily pay a premium for the better performing product in general terms however I think I would only pay the extra for the RED because I loved the RED colour because its such a strong striking colour. So I think the decision is going to be an easy one for people.

However if we see different limited colours come out, hypothetically a black or white version well then I think the small premium will easily be worth it to you if these are long term purchases. If it’s a stop gap subwoofer on your way to something bigger or more premium then get the standard T9X and save the extra for that big purchase later.

An Essential Audition Award is granted in recognition of a products high performance but with a certain uniqueness that makes auditioning even more essential.

For the full specification of the REL Acoustics T9X RED subwoofer see their website linked here