[TJB]

Hi.  Please help me.  I have a set of speakers with 8" woofers and 9" passive radiators. The specs are as follows:
Three-way, floorstanding loudspeaker. Drive-units (all anodized aluminum): 1" (25mm) dome tweeter, coincident with 4.5" (114mm) cone midrange; 8" (204mm) cone woofer; 9" (230mm) passive radiator. Crossover frequencies: 900Hz, 3kHz. Crossover slopes: Acoustic first-order, 6dB/octave. Frequency response: 37Hz-20kHz, ±2dB.

I'm looking for a subwoofer for better sound.  Would the REL Acoustics T/9x or T/7x be sufficient or do I need something bigger?  Loud music doesn't appeal to me.  However, I love good clean sound.  Please opine.  Thanks.

[I.Greyhound Fan]

What is the size of your room?

Will you be using it for music only or HT and music?

Those REL T subs don't go down too low although they sound good.  I prefer subs that go a little lower, maybe 20hz +/- 3db. 

Also consider Rythmik, SVS, HSU and even Martin Logan.

[TJB]

22' by 11'.

[I.Greyhound Fan]

22' by 11'.

Thats long and narrow.  Is it only for music or both HT and music?

[I.Greyhound Fan]

Which wall would it be on, the long or the short?

[rotarius]

You probably should do some measurements and figure out where your bass peaks and dips are.  I say this because sometimes you can have a bass dip around 50hz and a huge peak around 35-40hz which would make a sub difficult to integrate without some dsp thrown into the mix.

[WGH]

The only way to find out is to call REL. I have talked to them a couple of times and they are extremely nice and helpful. They will know what sub will work best in your room with your speakers.
REL are sub subwoofers and are designed for the lowest frequencies. My REL is adjusted to cover 30Hz to 18Hz. My main speakers go down to 34HZ so there is minimal overlap, a REL sub adds more than deep base, it adds space.

https://rel.net/

REL Acoustics America
800 Addison St.
Berkeley, CA 94710

contactus@rel.net
(510) 990-6005

[TJB]

In response to I.Greyhound Fan, my speakers are used for both music and HT.  And the sub will be placed on the long end of the room.  To everyone else, it seems that I might have to bite the bullet and go with REL's recommendation, which is the S/510.  I have been grappling with this decision for some time, and after speaking with a sales rep at an electronic store, I decided to revisit it because he told me that the two subs that I mentioned would integrate well with my speakers.  What I've been thinking of doing is to go with two of the T/7x's or the T/9x's instead of one S/510.  What do you guys think? 

[WGH]

The T/7x or T/9x would work fine if you had a music only system. The T/7x is -6dB at 30 Hz, the T/9x is -6dB at 27 Hz.

Neither sub will go low enough for a home theater setup where a sub has to go to at least 20Hz. Current movies like Dune, Blade Runner 2049 and the new Eternals have low, low bass that will tax even the best subs. If you lower the sub's gain so the woofer doesn't bottom out then the 30Hz bass looses impact.

The reason REL recommended the S/510 is because it is -6 dB at 20hz "for far stronger deep bass output between 20-35 Hz, vastly improved theatre dynamics, and an even more open and spacious soundfield which benefits both music and film. We turned to our NextGen3 amplifier, tuned to 500 watts with substantial reserves of power..."

Summing up, the T/7x and T/9x is for stereo, the S/510 is for home theater and stereo.

You want a sub that can play the latest movies without sounding like it's coughing up a hairball.

Blade Runner 2049

[Doublej]

What is the make and model of your speakers?

[JLM]

Suggest reading Floyd Toole's "Sound Reproduction" (either edition).  He's a well respected acoustician and recommends using 4 subwoofers, in corners or midway along each wall to tame inherent bass peaks/dips.  Earl Getty, another respected acoustician also recommends using multiple subwoofers.  Better than treatments or DSP.  In which case small/sealed subwoofers such as SVS SB-1000 Pro or Rythmik L12 would work well.  Another option is a "swarm" from Duke LeJeune of Audio Kinesis, a four subwoofer setup with external amp.  Duke has interesting loudspeaker design ideas.

A single sub can easily exacerbate the in-room bass peaks/dips.  I have three subwoofers in my audio system, ten GIK 244 absorption panels, and have owned a couple DSP's. 

[tull skull]

I would personally always choose a stereo pair of lesser performing subs to one big boy but I would always compromise home theater performance for music. I also believe that stereo information, even in low bass notes contribute to a more well defined stereo image/soundstage.

Do you DIY? The projects are almost limitless.

Check out "The Bucket Sub" project.

https://www.transcendentsound.com/bucket-sub.html

[Markwatkiss]

+1

[I.Greyhound Fan]

The only way to find out is to call REL. I have talked to them a couple of times and they are extremely nice and helpful. They will know what sub will work best in your room with your speakers.
REL are sub subwoofers and are designed for the lowest frequencies. My REL is adjusted to cover 30Hz to 18Hz. My main speakers go down to 34HZ so there is minimal overlap, a REL sub adds more than deep base, it adds space.

https://rel.net/

REL Acoustics America
800 Addison St.
Berkeley, CA 94710


contactus@rel.net
(510) 990-6005

Look at the spec's of the T series subs.  The T/9x only goes down to 27hz at +/- 6db.  Not very low.  For HT and music use, go with a sub that goes down to at least 22hz at +/-3db.


I would go with 2 Rythmik L12 subs or 2 SVS pro 2000 's.  Dual subs are better than 1.

[I.Greyhound Fan]

I would also look at the HSU ULS-15 MK2.  20hz at +/-1db.  You can get a pair-

https://www.hsuresearch.com/subwoofers.html

I also really like the SVS subs because of their cell phone app where you can make changes to the subs settings which is great if you are using it for HT and music.

[RonN5]

Do not underestimate the advantage of being able to adjust and tweak the blending with your mains with a 3 band built in parametric equalizer from your seat with their app . This is also a great sub and if you need something bigger… then they have numerous other choices.

https://www.svsound.com/collections/2000-pro-series?wiz_medium=cpc&wiz_source=google&wiz_campaign=704635121&gclid=EAIaIQobChMIxYa11sK-9QIVArOGCh3T3wUmEAAYASAAEgKuEPD_BwE

[WGH]

Floyd Toole uses 4 subs in his home theater, I would do the same if my room was bigger or I didn't mind the clutter. Luckily my REL Gibraltar G2 is just big enough.

Check out Floyd Tooles' personal home theater:
https://www.thescreeningroomav.com/single-post/2019/03/06/the-ultimate-real-world-home-theater-and-listening-room

Each of the 4 corners has a discontinued JBL Synthesis HTPS-400s 1 kW closed box subs with strong bass to 17 Hz using equalization.


Floyd Toole has written many articles about bass management, here are many of them:
Loudspeakers, Rooms, and Subwoofers
https://www.audiocircle.com/index.php?topic=58304.0


Sound Reproduction Third Edition by Floyd E. Toole, PhD
Designing a Home Theater - parts 1 - 3, free downloads
https://routledgetextbooks.com/textbooks/9781138921368/home-theatre.php

[RonN5]

If you have a tv in your listening room that can connect to your audio system and to YouTube you can run a frequency sweep video and listen from your seated position and you will hear the peaks and nulls. Then move your speakers and seating around and see what changes… hopefully the room isn’t too bad and you can improve things at the listening position with only one sub… but it may have to be located in a position you don’t like… which then means probably 2 subs to smooth things out.

[WGH]

One reason Floyd Toole uses multiple subs is so everyone in the audience hears smooth, even bass. But if you watch movies by yourself or with a partner then 1 sub is quite adequate. Place the sub where it sounds the best, adjust volume and crossover and enjoy. If there are big bass peaks and dips elsewhere in the room it doesn't matter, where you are sitting it is perfect.