REL Acoustics just released 3 new subs (T/5x, T/7x, T/9x)

[richard12511]

Actually the T9x measures quite well for the size according to sparechange's video review.

What kind of measurements did they do?

 

[Bassmantweed]

Can you describe your whole system?

Cambridge audio cxnV2 streamer dac
dynaco st tube amp ( technically it’s a vta- 120 bob latino amp with attenuator)
Revel m126be’s.

 

[Chrise36]

What kind of measurements did they do?

Frequency response

 

[Chrise36]

Cambridge audio cxnV2 streamer dac
dynaco st tube amp ( technically it’s a vta- 120 bob latino amp with attenuator)
Revel m126be’s.

Avoid using the tube amp for driving the sub use an rca splitter and a passive attenuator to control the sub.

 

[Bassmantweed]

Avoid using the tube amp for driving the sub use an rca splitter and a passive attenuator to control the sub.

100%. This is why I am looking for a good sub with the speaker inputs. Run from the amp to the sub nputs then from the sub outputs to the speakers.

 

[richard12511]

Frequency response

Frequency response is relatively meaningless for subwoofers. It's trivial to design a good frequency response for a subwoofer. Besides, Rthmik/HSU/JTR/SVS also have great frequency response.

What sets the good apart from the bad with subwoofers is distortion limited output and extension. Some might include group delay, but Rythmik/HSU/JTR also have excellent group delay.

The reason I see frequency response as basically meaningless is that you can equalize whatever response you want, assuming you have enough distortion limited output. You can't do that with speakers, as directivity is a thing, but with subs, it isn't. The same frequency response will sound the same, assuming distortion is below audible levels.

The problem I see with REL is that they have horrible distortion performance at low frequencies, and above that it isn't any better than the competitors. You can easily HPF an HSU/PSA/Rythmik/JTR/SVS to sound as "fast" as a REL, and in turn they will all be sound much less distorted. However, you can't EQ a REL to sound as undistorted and extended as any of those other subs, assuming price is constant.

 

[Chrise36]

Frequency response is relatively meaningless for subwoofers. It's trivial to design a good frequency response for a subwoofer. Besides, Rthmik/HSU/JTR/SVS also have great frequency response.

What sets the good apart from the bad with subwoofers is distortion limited output and extension. Some might include group delay, but Rythmik/HSU/JTR also have excellent group delay.

The reason I see frequency response as basically meaningless is that you can equalize whatever response you want, assuming you have enough distortion limited output. You can't do that with speakers, as directivity is a thing, but with subs, it isn't. The same frequency response will sound the same, assuming distortion is below audible levels.

The problem I see with REL is that they have horrible distortion performance at low frequencies, and above that it isn't any better than the competitors. You can easily HPF an HSU/PSA/Rythmik/JTR/SVS to sound as "fast" as a REL, and in turn they will all be sound much less distorted. However, you can't EQ a REL to sound as undistorted and extended as any of those other subs, assuming price is constant.

FR shows how low the sub can go. Dstortion in subwoofers even in high percentage is a measurement issue not an audible one.I think the fs of the driver and group delay is more important in how "fast" a sub sounds.

 

[richard12511]

FR shows how low the sub can go

Oh, I thought you were talking more about the smoothness of the frequency response. I definitely agree with you that frequency response extension is hugely important for sound quality.

Still, a simple frequency response at one level is not very helpful. What you really want to see is how that frequency response changes as you crank up the volume. CEA-2010 is the best measurements spec for determining sound quality we have atm, so I'd love to see some of these REL subwoofers measured in that fashion. Still, it is nice to see more than just CEA-2010. Databass actually goes way beyond CEA-2010 and gives you almost any measurement you can think of, which is why I'm sad that they seem to have disappeared. @hardisj is the best source atm(imo). He gives CEA-2010 and much more.

https://data-bass.com/#/systems/5ac87f9b9f7cce0004b8ad4e?_k=4zy8c6

^^^ Would love to see measurements that detailed for REL or studio subs. You essentially know exactly how it will sound.

Re: distortion, I agree with you that for the most part bass distortion is not all that important. Especially for giant JTR or Rythmik subs where the distortion is under 5% until below 20Hz. I would guess that some of the smaller REL subs would show audible distortion however in the lowest octaves. I could be wrong, though, but it would be nice to know for sure. I know my Infinity subs(for example) definitely exhibit audible "distortion" when you crank them.

 

[Chrise36]

Oh, I thought you were talking more about the smoothness of the frequency response. I definitely agree with you that frequency response extension is hugely important for sound quality.

Still, a simple frequency response at one level is not very helpful. What you really want to see is how that frequency response changes as you crank up the volume. CEA-2010 is the best measurements spec for determining sound quality we have atm, so I'd love to see some of these REL subwoofers measured in that fashion. Still, it is nice to see more than just CEA-2010. Databass actually goes way beyond CEA-2010 and gives you almost any measurement you can think of, which is why I'm sad that they seem to have disappeared. @hardisj is the best source atm(imo). He gives CEA-2010 and much more.

https://data-bass.com/#/systems/5ac87f9b9f7cce0004b8ad4e?_k=4zy8c6

^^^ Would love to see measurements that detailed for REL or studio subs. You essentially know exactly how it will sound.

Re: distortion, I agree with you that for the most part bass distortion is not all that important. Especially for giant JTR or Rythmik subs where the distortion is under 5% until below 20Hz. I would guess that some of the smaller REL subs would show audible distortion however in the lowest octaves. I could be wrong, though, but it would be nice to know for sure. I know my Infinity subs(for example) definitely exhibit audible "distortion" when you crank them.

I am considering building or buying another 1 or two subs.The Dayton drivers are impressive but i think i like more punchy sound like my car system with two 10" in a relatively small sealed enclosure. Maybe i could build two subs with 2 car audio subs each for punchy bass. I bought my Pioneer 10" for 60$ each.I also have an infinity car sub from my old car i actually bought because of the good measurements in data-bass some 15 years ago.

 

[Fat Ted]

Interesting thread, I'm thinking of adding a sub to my stereo system. I have Parallel 300 B interstage Monoblock amplifiers, REL suggest two subs.
Any suggestions where I should look would be much appreciated. Reading these forums directed me to buying a Chord Qutest.

 

[nerdoldnerdith]

Interesting thread, I'm thinking of adding a sub to my stereo system. I have Parallel 300 B interstage Monoblock amplifiers, REL suggest two subs.
Any suggestions where I should look would be much appreciated. Reading these forums directed me to buying a Chord Qutest.

The HT line are the only subs I'd recommend from them. They are pretty decent and not overly expensive. Everything else is wildly overpriced for what you get.

Otherwise, I'd just get a pair of Rythmik F12G's and call it a day. You don't need anything more for music.