I first learned about REL subwoofers from an earlier review that Steve did. Based on this, I emailed REL for more info about adding a sub to my vintage 1970-era stereo rig, and was surprised to receive a personal reply from the Chief Designer, John Hunter. Before he would recommend a specific sub, John asked for some details about my rig, my speakers, and the music I listened to. Based on my answers he recommended the REL T/5i. John also made himself available if I had questions on how to connect the sub to my existing rig. I could go on and on about how the T/5i has taken my sound reproduction to a whole new level of listening enjoyment. John's personal input, and Steve's recommendation made the REL a good buy. Highly recommend REL - and Steve, too!. 5 stars.

Thank you for all the stereo stuff I’ve learned from you Mr S.G. Over the years from the audio magazines and now on KZfaq

got one last year and what a difference! planning on buying another for my living room system. best thing Ive one for my system in a long time. great vid Steve

I used a Rel SHO 3 sub for many years with my stand mount speakers and loved it. Then I was lucky enough to be able to update my speakers to the Kef Reference 5. They are huge speakers and go deep, so disconnected my Rel - why would I need a sub too? But I was missing something that I had with my stand mounts plus Rel. So I reconnected the Rel, but set at a very low volume and crossover. I was amazed - it really opened up the soundstage again. For me it is definitely the way the Rel opens up the soundstage, rather than seeking more bass.

You through me for a loop when you said you used the sub with the "REL Soul VI". Then when I saw the picture I realized you meant the "Zu" Soul VI. I will be interested to hear what you think of the "Zu Soul VI when you do the review.

I can’t wait to hear your take on those new Zu’s. I love my dirty weekends and would love to upgrade a few years down the road

I completely agree on how good adding a sub is, and I particularly enjoyed your “seen and not heard” idea. I don’t know why certain reviewers say that blending a sub is time consuming or difficult - it isn’t (or doesn’t have to be). The difference even a small sub can make is definitely worth the extra expense. I’ll certainly consider this REL if & when I’m looking for my next subwoofer. Thanks Steve👍

I just added a pair of T9x to my open baffle Pure Audio Project Quintet 10 and like Steve said they keep up well. Great narrative Steve really hit the nail on the head describing how subwoofers are supposed to operate in a two channel system

Before I bought my REL R-305 from one who has become a fellow audiophile friend, I was worried about connecting it in with my speaker outputs - never heard of such a thing. But I read up on REL’s very informative website, and all fears subsided. I’m using the R-305 with my Magnepan MG-2.6/R’s and it is wonderful. Everything you said about the REL being a musical sub which enhances the speakers is spot on. Thanks, Steve!

100% all analogue. love the high level speaker connection. that suits my setup massively. Cheers Steve, love from an Irishman living in Nottingham England. top vid ✨

You're right about subwoofers opening up the space a little more. I ran into that also. This REL looks like a good candidate for my office system.

I own the previous Rel T5 model. I have two matched first with Dynaudio Emit 20 bookshelf speakers and now Dynaudio Emit 30 speakers. They sound incredible. Rel has definitely changed my thought process about subs with speakers for music. Rel subs are way more musical than the SVS subs I own. The whole idea of "NOT hearing the sub but the music" was a bit to get used to, but once you're locked in on the ideology of it, listening to a sub will never be the same. LOVE my Rel T5i subs. Definitely worth the money.

Great review Steve. Thank-you. I always learn something new from your videos. E.g. interesting engineering amplifier choice by REL. A "no time delay" class A/B amp offers less time delay vs a digital amp which has to sample and convert the analogue signal. I also agree with the logic of using the speaker level input because the hooked up speakers do potentially interact with the amp and you may want to maintain the timing integrity of that interaction in the deep bass. As you suggest, the other bonus with a sub or subs is you get a "low frequency tone control" to optimally dial in the bass tone of what you're listening to.

I currently have a MartinLogan Dynamo 600x sub and can say it definitely helps not only fill in the low end, but seems to make the mid-range seem richer, too. That said, I have always coveted the REL subs. One will be in my audiophile journey at some point. Thanks, as always Steve for a great review.

Excellent. Really glad to have another subwoofer review. If I had a subwoofer review for every time I heard "you might want to add a sub with these..."

This exactly what I have been looking for, thanks Steve

WOW! I just bought TWO of these in white!!! Got the two for $1150!..Runnin' both on high-current from my 40+-year-old Bob Carver C-500. Kicked the volume waaaaaay down on the subs and blended them in with my DynAudio Contour 20s…just to fill out the bottom end and give me fuller sound.! I got the subs on super subtle blend-in, as you say.. it is such a nice improvement to my stereo listening. Filled out the soundstage! WONDERFUL!! As a bonus I split the LFE from my Marantz AVR and hooked that up to both subwoofers 🔊 and turned that volume knob up a bit on each subwoofer to get a little more slam for movies. Can you say WIN/WIN?! It's a new audio world…..

I’ve just had my T5/x a few days and I’m so pleased with its addition to my system (Orchard Audio Pecan Pi Ultra streamer/DAC, Gamut D200 dual-mono power amp, Stereo Coffee kit LDR pre-, Sonus Faber Concerto Home speakers, Rega P3 and iFi iPhono2). My SF speakers did a great job but the addition of the single T5/x has definitely increased stereo depth and presence. I’m probably still dialling it in, however I’m impressed and it has contributed to my already great system just as I had hoped.

Very fine and helpful review. Thanks, Steve.

Steve I love ❤️ how you describe blending the bass / sub !!! As most people just don’t have the ear 👂 to achieve this !!! 😜👍🇦🇺

Steve, I purchased this unit some months ago to add to my Klipsh rp160m speakers , it has added another dimension to my music. money well spent - i say! I have mine on floor boards in a close listening set up.

I've had a REL Q150 for 20 years and recently added a second in immaculate condition for not much money. Both connected high level for music to my Roksan K2 and one for each side. The soundstage is amazing and they add air to everything. A pair also helps with bass loading in the room and corner placement is not actually necessary, in fact they sound better along the Speaker wall in the middle nearest to each speaker it is paired to. They both disappear once setup and just sit below the speaker output just extending them. I also have low level .1 for my AV surround setup and they shake the house when theres explosions etc. I'd never go to another subwoofer make and they would have to blow up for me to consider changing them.

Thank you for reviewing the Neutrik Speakon interconnect. I have watched several reviews for this sub that did not cover it.

Great review video Steve. Thanks so much for making it. I hope the algorithm treats you with, well deserved, good Karma on this one.

Speed and blend…u nailed what a sub in a two channel system should and MUST do. Your comments regarding dialing the sub in so bass appears to come from your speakers, not a boomy sub….spot on! I have never seen the 3 wire setup on the amp side!…geeesh!….but believe u it creates more definition vs straight RCAs. REL and SVS are only two sub brands I would upgrade to. Thx Steve!

I was going to spend a lot more on subs but I was urged to give these a go and I'm glad I did. I have two of them and they mate exceptionally well with my Raidho XT-1 speakers. The blend is seamless and the sound quality is far better than what I would have hoped from such relatively inexpensive subs. Also should mention that the build quality and appearance is right up there with my Raidho speakers - but at a fraction of the cost! Needless to say I am really please with this purchase.

Steve, This was very serendipitous for me as I am shopping Subs to round out my system. After visiting several audiophile's home systems around the country I realized they all used 2 to 4 subs and achieved great sound and soundstage. As I am in a medium sized room and my current speakers only go down to 40hz it seems the next important improvement I should address is adding a couple of subs. The down firing REL T5x sounds like the ticket. Thanks!

I’m really enjoying the two T5Xs I recently added to my set of JMR Bliss Jubilees.

not everyone has a pre-out Steve, glad they provided this option

Steve, thank you for reviewing this REL-sub! For about 3 months I have my own REL T7x. It's a killer sub for my modest living room (about 4x5 meters). It blends perfectly with my reworked Sansui LM220-Speakers and I have perfect bass and room pressurization on loud listening sessions. But in the late hours the sub helps to reduce volume and to have a nice sound either. The soundstage is much bigger now, and there is no boomy bass whatsoever. Thanks for all your work. I appreciate your way of reviewing a lot! Stay safe (you and Mrs Audiophiliac)! I can only recommend adding a sub to the 2-channel-system!!!

I'm using my T5i with totem mites. Everything Steve said. Love my Rel

Love my pair of REL Strata IIs using high level connection with Quad ESL and Gallo Stradas.

I have two T5 for many years. I had been using one for music production, and another in my secondary system with some so-so satellite speakers. I moved both of them to my living paired with Klipsch RP-600Ms driving by a Schiit Aegir. Once in the right place not only is the bass now punchy/musical/visceral, it opened the sound stage. When the source material calls for it, my soundstage is wall to wall. I've owned a LOT of speakers over the years, this is the best my system has ever sounded. In a few years when both my kids are out of college I may look at some high-efficiency towers, but I am afraid I will need to spend too much to see any significant improvement..

Good review. Love the shirts by the way.

I think I have a low budget winner. My 30 year old Kenwood bookshelf system finally smoked. (I tease my wife that it was from her country music.) The system was expensive when new and had pretty decent speakers for the time, LS-622. It was the right size and power for the room I used it in. I hadn't looked into audio equipment for a long time and set out on a replacement quest. Much of what I found was oriented towards home theater, not my goal. Then I stumbled upon the Marantz M-CR612. It seemed to be the perfect cornerstone for rebuilding. I test drove it at a great audio store, Listen Up. I listened to some fantastic B&W speakers (way out of budget) with and without the REL T5x. Then the wheels started turning. What if I mate the receiver with the Kenwood speakers and the REL, and then consider upgrading speakers later? Having gotten the REL dialed in and broken-in the combination sounds delightful. I play bass in a brass ensemble and a larger band, and listen for nuances in music. There's plenty of detail in this setup for my aging ears. The added bass detail is the icing on the cake!

Love my REL Subwoofers...usually adjust them so you can just start to hear them working...

I have a pair of the original REL T5's and love them. I had tried many sub set ups with my DIY Ariel TL speakers but always found it hard integrating the subs. Most subs did not have the natural dynamics and transient speed of the mains, giving the low bass a different character than the mid bass of the TL's. The REL's were a revelation and mated seamlessly with a minimum of set-up fuss. I am now using them with a pair of Magnepan 1.7i's and the result is equally seamless, the REL's just add that missing bottom octave that really helps the Maggies, while also opening up the soundstage as Steve mentioned.

I have a REL T/5 matched up with a pair of B&W 705 signatures and find the combo excellent. I have them connected through the high level input, as for me it was why buy a REL if you aren't? There are a lot of really good subs out there but this is what makes the brand unique. In fact that is why I got the REL, that and the nice compact size and finish. I was not looking for massive base, but to augment the 705's in a smaller area. Now I have it all matched up with a Doge 10 Mk 3, Prima Luna DAC fed by a IFI Zen streamer, LOVE IT!

I even have a sub (Energy 8”) in tandem with my Audioengine A5’s on my iMac computer system up in the office. I’m not a boomer guy by any stretch but the additional openness, or maybe ‘completeness’ of the sound is very apparent and appreciated.

Great review. I am looking to get either the 7X or the 9X to replace my Klipsch SPL 100. It does great for my home theater portion of my home theater system. I want something with faster and more musical bass when 2 channel listening.

Over the years it’s been interesting to note the shifts in audiophile culture viewpoints. In the early 80’s subwoofers we’re strictly a home theater thing, which itself was just emerging. Then too there was a somewhat de-emphasis on measurements that’s happened but more importantly bringing the idea that what sounds good to the listener is what matters most; that there is no such the as perfect, by its very nature this is reproduction. Language has shifted too. A few things like clipping and muddy were used whereas now the language is much more textural, nuanced and evocative of the visceral experience. All good stuff. Today, though my thinking shifted that maybe a sub in a two channel system isn’t heresy :-) Thanks, Steve!

My system incorporates a pair of Kef Reference 5 floor standers, augmented by a pair of Rel T9I subs. The combination works phenomenally well. I recently made some changes to my listening environment which has mo acoustic room correction or treatment. I got rid of my large 2 & 3 seater, leather, recliner sofas and replaced them with new, smaller, lighter, fabric, static 2 & 3 seater sofas. They killed the room. Eliminated any ambiance. I purchased a 3rd sub, a Rel T5X and placed it centrally, between my other subs, but on the opposite wall. I had to moderate the volume on all 3 subs, but, it did open up the sound stage. Return some room ambiance and give the illusion of a much larger room.

Great sub. I use one with two B&W CM-5's on an HH Scott LK-72 with eleven tubes, 80 watts. Will blow you out of the room... But sounds really nice. 😊

Just bought the t/5x. Don’t know much about the technically, but it’s sounds amazing. I’m so pleased!!! 💪💪🤭🤭🧸😊

I’m never been fully onboard with implementing a sub into an audio system. I prefer 2 channel. I have the T5i. I have it set to 1/5 on the min/max volume. The crossover is set at 30hz (lowest setting). The REL is hooked up to the high level amp input via the Arrow wireless transmitter. The REL is located on the opposite (back) wall in the corner of the room. Sounds wonderful and blends seamless with a pair of Spendor 4/5 Classics. I know the sub is there but I cannot locate it by ear..so I’ve got it dialed in to my preference. And you’re correct…the recording quality dictates the effectiveness of what you’ll hear. No speaker can fix a poor recording.

I just added a T5X to my Rega/ProAc setup... WOW. I can’t believe the transformation.

Thank you Steve for your excellent review. I have just installed the T5x in my over 40m² living room (Cambridge Audio CXA61 and Fyne Audio F502) and it sounds absolutely amazing!!!! Going for a larger sub like the T7x would have been an overkill, specially for my neighbours. I am using it for music listening only, seldom for TV. Great improvement in my listening experience. Best regards from Portugal

I second the use of two subs; the Ti series can be had for cheaper used so you don’t have to break the bank, or you could always get along with one new one and add another later if you come across a good deal. I personally would go bigger than smaller if you have the space.

Have to agree about down firing sealed subs as the way to go for music. I built my ACI Titan ll years ago and have never felt the need to upgrade. With the 12" driver and 250 watts, it works fine for H.T.as well in my relatively small room.

Ready to rumble. Nice one.

I like my Martin Logan Dynamo 800x. My local guy hooked me up, and I love it.

The speaker level is a must for music listening. It doesn’t pull power, but it makes sure that the subwoofer is not too loud or too soft based on the volume of the wattage going to the speakers. It will not rob your speakers of power. It is powered remember.😇 I have had a REL Sub for 15+ years no complaints.

Hello Steve and audio enthusiasts. Couple of points. Paul over at PS audio has mentioned in his subwoofer hookup videos that he recommends sending the signal to the sub with amplifier outputs for the same reason you mention. ALSO, within the manual for my Martin Logan Dynamo 1600x, ML HIGHLY recommends using the high level inputs for the best results!, so with that, REL has much company in that reasoning. (O;

Wow, that Rel Soul looks a lot like something Zu Audio would make! 😃

A while back now I was on the piss in York and returned to the pub with a real t5i as happened to notice a hi fi shop on my left when I popped out for a ciggie! Have to say once I’d tied it I was hooked. I’m purely 2.2 now but the .2 are still it’s stable mates. I’ve owned other subs but if you prefer music over tv rel on the high level connection is definitely the way to go

I use an Audioquest Black Dog subwoofer cable which comes with grounding wires at both ends of the cable which you attach to your system in case there is an audible hum. There is no hum in my system but regardless I recently connected the grounding wire to a screw on the chassis of the amp as well as to a screw on the sub frame. I find that the bass response is improved quite a bit, tighter and digs deep. I have no idea why. Maybe there was some stray current.

The demos and outtakes on Abbey Road and the White Album are pretty special as well. I listen to those more than the original.

I have a REL Q50 that I bought in 2007 for £150 secondhand, It works in pretty much the same way, the companies philosophy still rings true after all these years... Nice to see! I've heard some larger and more modern units by them, but they share a similar sound, setup and overall feel, They are definitely better on the high level inputs, they do take some playing around with in regards to room position and levels, but yeah... You will find the sweetspot for your room and be in heaven, in 'REL speak' it's all about finding the exact position/levels and 'pressurising' the room... I love that term! (hence the corner position) The guy that designed the boards was ex Navy, I believe he designed boards for submarines, If you open up a REL you will find over-engineering of an epic scale, FR4 boards twice as thick as necessary... Traces thicker than ya momma... Components 2x over-rated...that's what he learned in the navy, if it could possibly break... then make sure it doesn't! The Q50 at 50 watts is great for a small UK living room, 125 Watts is probably more fitting for the average US home though, My mates with 200W to 300W subs by Pioneer, Toshiba, (insert cheap home theatre sub here), etc. could not believe the difference, theirs just didn't integrate and stop booming, my paltry 50W sub seamlessly integrated with the main speakers and room acoustics and kicked arse! 🔊⚠️🤯 It was good for films (I have a Marantz surround processor) but much, much better for 2.1 It's like products from many other quality Hifi manufacturers... It's not about the numbers... It's about the experience

REL are really well built .... Rock solid and go deep without distortion ..

I have an "original" T5 and a T5i. Two subs is the way to go! Originally I had them with KEF LS50 and then the Magnepan LRS. More recently I hooked the T5 to a pair of Infinity Kappa 7s. Pleasantly surprised how much the T5s added when I shoved them almost into the corner with the Kappas pretty far in front and diagonally away. The bass boost was impressive in the corner and went deeper than the 12" Infinity speaker on the T5.

I have two of the smaller RELs connected in conjunction with 2 mono amps and some Kong-sized JBL 4430 improved clones.

I had to look around my listening area to see if you were in the room, Steve. Fast & tight bass is achieved here with just a few minutes setting the crossover to the level that the individual listener prefers. My go to test track is Secret World by Peter Gabriel with Tony Levin just jamming on that Chapman Stick. Eighth notes way down in the 30hz range and each note is distinct with no boom. My room has a stone floor and you cannot ask for a better surface for fast and tight low end. A great sub never gets in the way of your main speakers and goes where needed. My speakers (XR-50) are only 18 inches tall but you think they are 6 feet tall now. Hard to explain the difference you hear on a comment section, but it is there. Just my 2 cents. Great info in your video.

You can even run them from the speaker terminals. This can be a better option if you are running a pair near the speaker positions.

You meant *Zu Audio Soul 6 instead of Rel. Looking forward to that review.

Yessss they do make a difference‚ in a great way. Have two REL 5‚ and every ting sounds more real‚ the thump on a instrument‚ the fingers sliding on strings‚ the pedal's on a piano‚ all come alive. They also expand the posebilety of trying more bookshelf speaker's and never worry about having enough low end.

Great review Steve. You explain the crossover adjusting just perfect. It would be a-shame if folks had the REL set up wrong.

…to add to my previous comment, ‘Flight of the Cosmic Hippo’ from Béla Fleck & the Flecktones is sounding better than ever and the sub seems well-integrated, just as I would wish it!

Thanks Steve, great review. Do front firing sub-woofers sound more natural than downward firing subs?

Woooo! More sub content! Any chance you get your hands on some of the REL non-down firing subs? something like an REL Acoustics HT/1003 or 1205?

I like that it comes with the cable to connect it up no need to buy anything else all you need is in the box. I believe you mentioned the Zu soul 6 not REL. rocking a T9i with B&W 603 anniversary edition. Blends well and adds so much depth. You correct yourself later in the video

With the REL having only a single low passed RCA input, were you able to connect only the left or only the right channel off of your amp? That would make the big difference in sound between that and using the high-level stereo summed input.

This sub is a monster compared to my T5i. I could hear the difference immediately. Much heftier punch and deeper resolution.

Great video! I have similar taste in sound in that I want something punchy for music versus shaking the foundations of my house. I chose REL over SVS, and I am very happy. I listened to an SVS in a store and found it to be a bit too boomy, while the REL was tighter and provided a better representation of the music to my ears.

FYI- there’s IS a smaller sub in the T-series. T-Zero Mk3. Kick ass little sub 👍

Connecting a high impedance input across the speaker terminals would allow the sub to also get the counter EMF from the speaker as part of it's signal where the amps' sub or preamp out would not. So yes it would get a slightly different signal.

I could fit this lil baby inside one port of my captivator. Lol so cute. I was either gonna go the rel route or what I have now believe it or not. One day I will try one. Amazing I bet cheers. I think if it was easier to get that really powerful low end with amazing lfe and a subwoofer that can go into single digit hz and have that and have the quality of bass be just as good or very close to the rel you would really really really enjoy what a massive powerful ulf subwoofer can do. It’s actually quite amazing it adds to the music to how the artist intended it to sound you can hear everything or and did I mention feel.. cheers

I just received this sub 2 weeks ago pairing with my sonus farber. I’m not a audiophile but it feel like I just bought a new system. It’s the cheapest upgrade you can do for your system. My question is breaking in. There are some KZfaq for sub woofer breakin. Can you recommend? Thanks much.

Thanks Steve. If you could answer, should we expect a better sound joining a Rel Sub to a Tannoy GR Turnberry? And what sub? Can you share your opinion please? Thanks.

Steve, since you are now a subwoofer fan these days (maybe you have been one for much longer?) I came across a different kind of subwoofer that is based on a unique design called "distributed bass". It uses multiple smaller subwoofers to overcome the difficulty in producing low frequencies. The two brands I see on the net are The Swarm subwoofer system and the DEBRA subwoofer system (the latter is a Swarm-licensed version). I'd love to hear what you have to say about this concept and how it sounds.

Hi Steve. Wondering if you could say a bit about the size of the subwoofer. I was surprised that an 8" sub would work well with a floorstander with 10" drivers, thinking that the sub should be at least 2" or so wider in diameter... Is this completely wrong?

Make sure the driver size of the sub isn't a huge difference to the largest driver of your speakers. It will integrate better if there isn't as drastic of a difference in size.

Is it best to set front speakers to small when having sub, or still set them to large?

I have a pair of the T/5x predecessor the T/5i and I don't use them any longer. No matter how I hooked them up - RCA or high level - there was a hum in the background during those silent moments between tracks. I tried everything I could to eliminate the hum to no avail. The hum bugged me so much that I decided to just pull them out of my system and go without. I eventually stumbled across a deal on an Elac 3010 sub and there was no hum. I ultimately put the 3010 back in the box, too, as I upgraded my speakers to Tekton Mini Lore's that had most of the base that I was looking for without the hassle of having to deal with more equipment.

I have 2 with my Maggies. Great match. Also have my original Rel Q150 with my Klipsch Heresy in a 2nd system.

I purchased a Quake II - the way it disappears, and the speakers sound like the bass is coming out of them is surreal.

Hi Steve! Where in the HT receiver would I need to connect the sub’s high level connection cable to? Usually in receivers you have ports for main, center, rear speakers (in 5.1) and an RCA for sub connection.. am I missing something?

I ended up buying the Predator 1508HT @$999 and I bought 2. Free shipping and 60 in home free trial. Maybe not quite as musical but it's always about choices...

You said Rel Soul 6 and i was like those look like ZU speakers and for anyone wondering its the Zu Soul 6 speakers he used

You recommended this and other podcasters liked this T5x so much I bought one before the price increase I like how clean it plays with music but you failed to mention the plate amplifier hum i noticed when it's not in play or maybe I have a bad one or well maybe it;s because it's not had its 24 hour burn in maybe this hum will decrease after some break in time I hope.

Now my question is. Is it worth going from the T5i to the T5x ? Thanks.

Hey Steve, have you had a chance to compare this unit to the Martin Logan balanced force 210??

Steve I need your help, can’t decide between REL T5X VS SVS Micro 3000 to pair with my Klipsch RP-600 and my KEF LS50 music only listening. Which one would you pick?

How would the REL T/5 match up/blend in with the Magnapan LRS+ speakers?

Most speaker systems other than double pair of KLH-9’s have the classical music rendered by the double base reproduce its timbre that of a ball park Hammond organ with just one slider out. I would like for you to get a copy of any double bass concerto, or if not available, Schubert Trout quintet as test material.

I was wondering your opinion on matching the Rel subs with Klipsch Hersey. Was curious why that was not part of your review ?

Do you think that the T/5x will be fine in a system made of a Emotiva xpa2 gen3 with the Magnelan LRS+?

Hmm. A FirstWatt J2, set of ELAC DBR-62 and a REL sub. Fed by a modified XDA-2 and you have my current system! Yes, the REL should be set up so that you forget its there. Sometimes I switch it off for a minute to refresh that 'aha' moment.

Hi Steve I am using a Rel Stadium 111 sub with Vienna acoustics Beethoven concert grands. I have a change of circumstance and would like to pair the Rel with bookshelf speakers. Will it be suitable Any suggestions would be appreciated.

hi steve, do i have to connect the t5x to an amplifier? and if yes, how to connect to an active speaker? can it use the amplifier from the active speaker? my speaker is ae1 active. 🙏

Will downward firing be a problem for family members downstairs? Seems like it might be with our wooden floors, perhaps the KEF might be better for me.