How much faster of a sub is the REL T5X vs SVS SB12-NSD


Looking for some advice as to how to determine how much faster one sub is from another. I’m not sure how to determine this just by reading the specs and could use some help in educating me with this.

Currently I have the SVS and sounds good but feel after all my adjustments and crawls, just can’t get the slap on some of the bass I desire. Everything I’ve seen about the T5X is it’s one of the fastest subs out there and blends well with Maggi’s 

Main speakers: Magnepan .7’s

Sub: SB-12NSD

Rogue RP-1 Preamp

Carver Crimson 275 Amp (Yea,I know about the test’s and read all the posts about it, it sounds good, so please don’t hijack this post with comments regarding the amp.)

I’m really tempted to take advantage of the REL Home Trial, but hope I can get some assistance first so can make an educated decision.

Thanks 

 

flasd

You might consider another contender and no pretender …VANDERSTEEN 

The VANDY is not just another subwoofer.With its internal 300-watt power amplifier, it is the perfect compliment to any sound system.

It consists of three 8″ floor-facing drivers, each with a massive motor. So why not a more typical single 12″ or 15″ design? The mass of a larger driver will not allow it to respond as quickly as the Vandersteen 8″ drivers to today’s demanding recordings. The VANDY’s  8″ drivers are designed to handle the content but be “fleet of foot” at the same time.

 

 

All right, I was gonna leave the details of woofer "speed" to those who cared enough to watch Danny Richie’s Tech Talk 6/Fast Bass YouTube video, but in light of the akg_ca post directly above, I’ll say more.

The Vandersteen is indeed a very fine sub, one with which I am quite familiar (Brooks Berdan was one of Richard’s biggest dealers). But to say "The mass of a larger driver will not allow it to respond as quickly as the Vandersteen 8" drivers" is to over-simplify what is actually going on. Again, for a very detailed explanation, watch the video.

At one point in time, Rythmik Audio was offering sub models using 8", 12", and 15" drivers (he has discontinued the 8", and added an 18"). Contrary to common audiophile myth, an 8" woofer is not necessarily "faster" than a 15", 18", or even 24". I have an 8" sealed woofer, and my open baffle 12" and sealed 15" Rythmik subs sounds "faster" than the 8".

To understand why I used quotation marks above, I implore you: watch the video! As a simplified teaser, I’ll just say that the perceived "speed" of a (sub)woofer is not a matter of how fast a driver will respond to the signal (bass frequencies are quite slow), but in how fast it returns to rest when the signal stops. Yes, the moving mass of a driver (the cone) and its stored energy (watch the video ;) is part of that phenomenon, but so is the motor (magnet structure), it’s suspension, the cone material, and numerous other factors.

But imagine a driver which includes not just a voice coil, but a sensing coil which electronically applies the "brakes" when the signal ends, forcing the cone back to it’s rest position---faster than an uncontrolled cone, whatever it’s cone size. That’s servo-feedback, a patented form of which Brian Ding employs in his Rythmik Audio subs. Perhaps you have heard servo-feedback woofers before. I had: I owned a pair of Infinity RS-1b’s for a time, which just happened to use multiple 8" servo-feedback woofers in it’s bass towers. Not even close to the sealed-enclosure 15" Rythmik.

Now, imagine a servo-controlled driver installed not in a sealed or ported enclosure, but in an open baffle frame. Harry Pearson loved the sound of the twin bass panels of the Magneplanar Tympani T-IVa dipole planars (a pair of which I own), using them as woofers in his Tympani/IRS super speaker. I too love that kind of low frequency reproduction, which replicates the sound of upright bass, cello, the lower registers of piano, and of course drumheads like no other woofer I’ve heard. Until I built a pair of GR Research/Rythmik Audio Servo-Feedback OB/Dipole Subwoofers. THE sub for planar loudspeakers!

Use a sealed box sub with Maggies,  servo controlled as well.  Much faster than a ported design.  And do not put it in a corner,  I have mine next to the electroncs rack and in between the Maggies.

I’ve had panel speakers since the 80’s and tried to buy or build subs to go with them and NONE are as fast as the panels. I built 7 prototypes ranging is sizes of both drivers and boxes. Used active and passive crossovers and all solid state power. Also tried every position possible. 
I also tried, Velodyne, REL(old models) and an old SVS12” and the last is a brand new SVS 2000Pro. Depending on your room, you can probably get close, but….

One thing, whatever you get, make it a sealed box, not ported.

All the best.

JD

Oh, I currently have a pair of Acoustat Model X’s and they still sound great!

JD