Definitive Technology Arms their New Descend Series Subs with Cool Tech

[shadyJ]

Definitive Thechnology can't be happy with this forum. They announced the new Descend subs and SVS steals all the attention. I guess they're paying the price for overstating their specs. This series better have amazing performance; too many though players on the subwoofer arena, Definitive needs a "KO punch" or one out of the park! Are they ready to deliver?

These subs may be good. Deftech definitely has the engineering team to make a good sub happen. We will see if I can get some in for review...

 

[luis1090]

These subs may be good. Deftech definitely has the engineering team to make a good sub happen. We will see if I can get some in for review...

Well you should get one for review assuming they're confident on their efforts; on the other hand don't expect one if they just came with another half baked effort. Based on price I'll expect performance and value.

 

[Pogre]

Definitive Thechnology can't be happy with this forum. They announced the new Descend subs and SVS steals all the attention.

Right? Who was the scoundrel that brought up SVS in this thread? Pitchforks!

 

[ryanosaur]

Right? Who was the scoundrel that brought up SVS in this thread? Pitchforks!

Do you want an answer to that?

Spoiler: Who Dunnit?!

First Mention:

Definitive Technology Arms their New Descend Series Subs with Cool Tech

Definitive Technologies announced the release of their Descend Series subwoofers. The new line consists of four high-performance models ranging from 8" to 15" drivers and dual passive radiators designed to produce more impactful, dynamic, and extended bass response than with competitive brands...

forums.audioholics.com

Second Mention:

Definitive Technology Arms their New Descend Series Subs with Cool Tech

Definitive Technologies announced the release of their Descend Series subwoofers. The new line consists of four high-performance models ranging from 8" to 15" drivers and dual passive radiators designed to produce more impactful, dynamic, and extended bass response than with competitive brands...

forums.audioholics.com

 

[Pogre]

These subs may be good. Deftech definitely has the engineering team to make a good sub happen. We will see if I can get some in for review...

I really would like to know more about them. DefTech has earned themselves somewhat of a bad rap for bloated specs, but with the Demand series speakers they appear to be working on cleaning it up. I never read anything about kickass subs with passive radiators tho. I've read that they perform pretty much on par with their ported counterparts, but never see any recommended.

I know they're out there, but quite a few of them don't follow the "double the surface area" rule and have only 1 radiator, which I assume is why they don't get recommended, lol. The only example of a really good sub with that design off the top of my head are the Sunfire subs I think @luis1090 brought up earlier. Are they just hard to design? Expensive?

 

[Pogre]

Do you want an answer to that?

Spoiler: Who Dunnit?!

First Mention:

Definitive Technology Arms their New Descend Series Subs with Cool Tech

Definitive Technologies announced the release of their Descend Series subwoofers. The new line consists of four high-performance models ranging from 8" to 15" drivers and dual passive radiators designed to produce more impactful, dynamic, and extended bass response than with competitive brands...

forums.audioholics.com

Second Mention:

Definitive Technology Arms their New Descend Series Subs with Cool Tech

Definitive Technologies announced the release of their Descend Series subwoofers. The new line consists of four high-performance models ranging from 8" to 15" drivers and dual passive radiators designed to produce more impactful, dynamic, and extended bass response than with competitive brands...

forums.audioholics.com

Yeah... I knew who it was. I just wanted someone else to point it out! Lol.

 

[Pogre]

Well you should get one for review assuming they're confident on their efforts; on the other hand don't expect one if they just came with another half baked effort. Based on price I'll expect performance and value.

I'm cautiously optimistic. They put together some great speakers with honest specs in the Demand series. I'm hoping it's gonna be a trend.

 

[ryanosaur]

I really would like to know more about them. DefTech has earned themselves somewhat of a bad rap for bloated specs, but with the Demand series speakers they appear to be working on cleaning it up. I never read anything about kickass subs with passive radiators tho. I've read that they perform pretty much on par with their ported counterparts, but never see any recommended.

I know they're out there, but quite a few of them don't follow the "double the surface area" rule and have only 1 radiator, which I assume is why they don't get recommended, lol. The only example of a really good sub with that design off the top of my head are the Sunfire subs I think @luis1090 brought up earlier. Are they just hard to design? Expensive?

It effectively let's you forego the space taken up in the box by ports (very long ports or ports with large volume can benefit from replacement with PRs). IIRC, the mass you add to the PR cone needs to correlate in some manner to the mass of the air that would be in a properly tuned port for the cabinet being designed. I do not think (could be mistaken) that you need to double the surface area though the Sd should be larger than the driver by some margin, you also do need to account for the resonance of the PR in the equation, along with the mass adjustment.
Keep in mind, because you are effectively adding another driver (or two) to the build, cost does increase accordingly.
Some may see it as a con: the roll-off occurs slightly higher than in an optimal ported design, and the roll-off is slightly steeper.
Salk is a good example if you look at his builds with PRs (ss9.5, SS8, and he uses them in his Rythmik Sub builds if asked).

Just for kicks:

Passive Radiators: Madisound Speaker Components, Inc.

Free support for loudspeaker projects, sourcing OEM speaker building supplies, and passive crossover design. We sell raw speaker drivers (tweeters, woofers, subwoofer, midrange drivers, full range drivers), speaker kits, amplifiers, capacitors, resistors, and inductors.

www.madisoundspeakerstore.com

 

[luis1090]

Right? Who was the scoundrel that brought up SVS in this thread? Pitchforks!

Guilty as charge...but I'm not the only that has lost faith on Deftech, you guys are riding the same train!

 

[ryanosaur]

Guilty as charge...but I'm not the only that has lost faith on Deftech, you guys are riding the same train!

I don't disagree... in fact if you were to look back at many of the things I've written about DT (prior to the Demand release), you'd likely get a little misty-eyed at the restraint I've shown here!

 

[Hetfield]

Guilty as charge...but I'm not the only that has lost faith on Deftech, you guys are riding the same train!

I have lost all faith in Def Tech and I only owned Def Tech for 20 years. I had some expensive ones too, BP7002 were the most expensive speaker I ever owned. The new line looks very cheap, and the sub amps seem to failing a lot. Also bipolar speakers are tough to get placement right. You need a wall directly behind your front soundstage.
When I moved on I wanted to move away from bipolar speakers and built in subs which I think doesn't add much to the overall sound.

Sent from my Pixel 4 XL using Tapatalk

 

[ryanosaur]

I have lost all faith in Def Tech and I only owned Def Tech for 20 years. I had some expensive ones too, BP7002 were the most expensive speaker I ever owned. The new line looks very cheap, and the sub amps seem to failing a lot. Also bipolar speakers are tough to get placement right. You need a wall directly behind your front soundstage.
When I moved on I wanted to move away from bipolar speakers and built in subs which I think doesn't add much to the overall sound.

Sent from my Pixel 4 XL using Tapatalk

A good Bi-Pole design isn't necessarily a bad thing. The application, however, is the key... and the devil is in the details.
I find, for example, that I get a lot more out of my open back Mid (bi-pole, planar) than I ever expected. Perhaps it's a happy accident.
But the "newer" BP9XXX series were absolutely horrid things. I also had a DT salesperson tell me not to buy DT Subs, rather he told me to check out SVS!

Other than the price, the new Demand Series do look like very attractive Speakers from a performance standpoint. Moreover, they dropped the gimmick powered woofer section and the inflated specs! This is good.

 

[snakeeyes]

I can forgive the inflated specs on those older models, but telling people they don’t need a sub at all because the towers have amps is what bothers me. IMHO, every home theater multichannel system needs a real sub. Otherwise you are missing out.

 

[lovinthehd]

I can forgive the inflated specs on those older models, but telling people they don’t need a sub at all because the towers have amps is what bothers me. IMHO, every home theater multichannel system needs a real sub. Otherwise you are missing out.

Let alone the limited lower response and limited positioning afforded by such speakers....

 

[Hetfield]

I can forgive the inflated specs on those older models, but telling people they don’t need a sub at all because the towers have amps is what bothers me. IMHO, every home theater multichannel system needs a real sub. Otherwise you are missing out.

When I first got into home theater when I was 20/21 I got into it with Def Tech. That was when you had to go to an actual audio store to buy it, not BB or online. I fell for the "you don't need a sub" because it's built in because I didn't know any better. But Def Tech also sold stand alone subs too so I was dumb enough to buy one. Talk about terrible value. Now I know better and I know where the value is and not always spending the most money. In fact I'm the opposite now, total opposite, the least I can spend for the best bang for the buck is now my Bible.

Sent from my Pixel 4 XL using Tapatalk

 

[NINaudio]

You know that puzzle box in the "Hellraiser" movies that people opened and then demons came out and took them to hell where they were tortured for all eternity? That is kind of what testing subwoofers is like... You might be sorry you asked...

I used to spend 8 hours a day making lipstick...

 

[NINaudio]

I'm cautiously optimistic. They put together some great speakers with honest specs in the Demand series. I'm hoping it's gonna be a trend.

If you look at the frequency responses given for this new series, they actually seem to be quite believable. The only one that they state getting down to 20 Hz is the 15" model. And they state the lower frequency response of the DN8 as 35 Hz, which is pretty close to what I've measured with my old SC4000 (previous 8" sub with dual passive radiators), which they listed as having a lower frequency response of 16 Hz....

So, I think they may have learned their lesson when it comes to overstating specs. (in this case at least)

 

[luis1090]

If you look at the frequency responses given for this new series, they actually seem to be quite believable. The only one that they state getting down to 20 Hz is the 15" model. And they state the lower frequency response of the DN8 as 35 Hz, which is pretty close to what I've measured with my old SC4000 (previous 8" sub with dual passive radiators), which they listed as having a lower frequency response of 16 Hz....

So, I think they may have learned their lesson when it comes to overstating specs. (in this case at least)

You're right, I noticed that as well. I just think a good designed 12" subwoofer should be able to reach somewhere between 18-20hz with meaningful output especially if you're into movies. Hopefully they learned the lesson and now are understating the 12" at 25hz.

 

[panteragstk]

I used to spend 8 hours a day making lipstick...

I'm afraid to ask what this might be a euphemism for...

 

[NINaudio]

I'm afraid to ask what this might be a euphemism for...

No euphemism at all, it's quite literal. I was a cosmetic chemist before going back to school for Physics.