what does my subwoofer set up compare to? (1 Viewer)

[Haru]

Hi guys! I am new to this forum and am delighted for the oppportunity to learn and participate.
I would like to start by asking about my subwoofers. I bought a pair of NHT 2.9s a few years ago for stereo duty. I was quite happy with these and determined that I would build my HT around them. So, eventually, as money permitted I made the transition from stereo to HT, starting with an HDTV and soon to end with a pair of speakers added for the 6 and 7 of 7.1 channels.
What I have:

• NHT 2.9 (main)
  NHT AudioCenter-2 (center)
  NHT 1.5 (rear)
  2 x NHT SubTwoi

THe audiocenter-2 and 1.5 rears run directly off the Denon 3802. For the front L/R, I have routed the line level output from the reciever to the NHT subwoofer controller (which is stereo). the signal is low passed at 50 Hz. and sent to the subwoofers. the high passed (also 50Hz) component heads to my 250wpc Carver power amp, which them drives the NHT 2.9s.
The LFE output of the denon is also routed to the subwoofer controller, and gets mixed into the signal going to the subwoofers. The level of LFE in the mix is controlled by a knob on the front of the controlled.
I bought the NHT subs just because I had all other NHTs, there was great deal going ($1650 for two, including two controllers, even though I need only one), and I could not imagine not getting good performance out of 4 NHT 1259 drivers, modified ( I believe) for subwoofer use.
But here is the thing. The SubTwo i was in production was only a very short time, and there are NO official reviews anywhere. It never featured in any magazine tests or comparisons, nor have there been any listening reviews anywhere except on consumer review websites.
Now, I have what I have, and I am quite satisfied with the performance. But I am still very curious about how my subwoofer set up compares with what else is in the market. There are some notable subs out there, the Paradigm PW2200 and Servo-15, the Velodyne HGS18, the Hsu VTF-3, etc. and I hear great things about these and others, and I am VERY curious about how my system compares with these, but I can't find anything.
So I thought I'd ask you guys. Anyone have a clue?

 

[Tom Vodhanel]

These look like the old SW3i doubled up. I have seen some data on the SW series in the WSR showdown,and somewhere else too but I can't remember. Whatever you see for a single Sw3, just add 12dBs across the board if you have all your woofage in one corner. If you have them in seperate corners...add 9-10dB.

TV

 

[Haru]

Thank you. Does anyone know where I can find the measured numbers for the SW3P? ANy one know of any comparisons?

I must remember to ask NHT if the SubTwoi's performance is essentially the same as two units of the SW3P. I think its a similar driver, but the amplification is now built into the cabinet (500W Sunfire) and the crossover is a much more complex unit. It may be the same driver, but I have to wonder if NHT has applied to the subtwoi anything that they learned with the 3.3 and SW3P. If they did, I imagine a single Subtwoi should have some advantage to 2 SW3Ps.

 

[Jack Gilvey]

I don't recall any measurements on the 1259-based subs. They're not extremely-long-throw units, being designed instead to go low and flat in a moderate sealed box. I'd expect deep-bass output from a sub using two of them to be on par with something like a VTF-3 or one of the higher SVS models...just a guess.

 

[Sihan Goi]

You can find frequency response of the 1259 driver at http://www.madisound.com/nht1259%20sub%20kit.html

 

[Haru]

thanks Sihan. I am not sure that specs of the raw driver or of kits assmebled around it are telling of this particular application.

Jack,

your comment as regards the VTF-3 increases my curiousity for hard numbers even more. Near mythic reputations almost demand it.

 

[Scott Oliver]

Haru,

I think your worrying yourself over nothing.

You have 4 - 12" woofers in sealed boxes produced by a reputable company, that you are happy with.

Plus you have external control boxes with a high level of hook-up and crossover flexibility.

Unless you are just wanting to spend the money, I think you would have a hard time of finding something that would be a significant lateral move.

 

[John F. Palacio]

I've gotta second Scott Oliver's comment. If you are worried about somebody "out subwoofing" you, then you'll be worrying forever.

I have read so many threads of others with top-of-the-line subs and gear that are not happy with the sound. Whether that's nitpicking or room acoustics, I do not know. But if you're happy with what you have, stick with it.

 

[Haru]

John and Scott,
considering that I've only recently bought these subs, and that I have not BEGUN to approach their limits, I have no desire to replace them. They are extremely understressed in my application. Levels sufficient to frighten the neighbors and deafen me, the 4 cones are barely stroking more than 1/2" or so.
I guess I am just hoping that somebody will tell me that had I got an HGS18 instead of two of these, I would not have had even more.
petty, to be sure, but the need for external reassurance is a human weakness, is it not?

 

[Haru]

on this topic, actually, I'd like ask another question.

the NHT 2.9 towers have a fairly substantial bass output. THe 10" driver in each speaker is a variation of the 1259 driver, and is what NHT used in the SubTwo. The subtwoi, which I have, is the same sub as the subtwo but with 12s instead of 10s and a controller with more functionality.

While the 2.9 towers do not have the sort of bass that shakes the rafters, its actually quite enough that when I did not have the subs, I was quite satisfied with what they could do.

Now, that I have the subs, I am not inclined to set the cross over too high for wasting the capacity of the 2.9s. So right now, the crossover is set at 50Hz. Do you folks believe that the 2.9's output at 50-70Hz will npt keep pace with the subs'? I know in a max output face off, the subs will out-pound the 2.9, but I am trying to understand if I should get better results by moving the crossover to 60 or even 70 Hz.

Right now, I have the subs sitting out the outside of each 2.9. I though that since they are in stereo (even though stero bass is rare and probably pointless anyway), having each close to its respective main channel would minimize issues with delay. I admit to understanding very little of subwoofers so I have a lot to learn yet.

But anyway, my reason for mentioning that is this. Since the 2.9 and sub of each channel sit next to each other, perhaps they could be set up to function as one unit. So what would be the optimal way of setting the crossover and levels? would it be advantageous to set some overlap in the high pass and low pass?

Is there ANY conveivable advantage in trying to set up the system the way I am, or should I just shove them both into a corner and forget about stereo antics?

 

[John F. Palacio]

"I guess I am just hoping that somebody will tell me that had I got an HGS18 instead of two of these, I would not have had even more."

That's what I meant when I wrote about your worries on somebody out-subwoofing you.

In regards to crossover frequency. There are two schools of thought.

1- All low-freqs should come from one source (Sub or subs-placed-together) On this scenario you should cross at 80 Hz and place your subs together.(6 dB gain Vs single sub)

2- Low freqs should retain the channel separation. In this case you should cross at 50 Hz. Your subs can remain together or you can place one near each of the L-R speakers.

 

[Jack Gilvey]

considering that I've only recently bought these subs, and that I have not BEGUN to approach their limits, I have no desire to replace them. They are extremely understressed in my application. Levels sufficient to frighten the neighbors and deafen me, the 4 cones are barely stroking more than 1/2" or so.

In that case, don't worry about it. If they go deep and loud enough, you're set.

 

[Sihan Goi]

Haru, yeah I think that's the frequency response graph of the assembled subwoofer kit, but it gives you a picture of what the drivers are capable of. Anyway, the 1259 is an excellent driver and NHT's best, and also quite popular among hobbyists. The Sub Twoi, AFAIK, is also a great subwoofer, but not so popular coz NHT in general isn't that popular. In fact I think they're underrated. They make great speakers(The NHT 3.3's as well as your 2.9's outperform a lot of speakers beyond their price range) so don't worry about being out, or in this case, "under"-performed by someone else...just enjoy the music!

 

[Chris PC]

Could you descrive the "controller" ? Is that something that is available for sale separately?

 

[Haru]

the controller is a stereo unit that has two channel inputs and outputs. It has line level low pass (40-180Hz 18db/ocatave), and high pass (40-120Hz, 12db/octave, fixed speaker level high pass (100Hz at 8 ohms 6db/octave). It has a 0-360° phase control and defeatable variable response control. It can either be set to be flat, or you can increase output at the cost of extension: its continuously adjustable between two outside boundaries. In addition to Left and Right line level inputs, it also has dual LFE inputs (one for each sub), and the ability to control how much LFE is mixed into the output signal. thus you can set your reciever level for the sub equal to the left and right mains, and adjust the LFE level from this controller.
Finally, it has a gain control that acts as the volume knob. And oh yeah, its standard rack width (17") so that it can be put in amongst all your other components and it fits right in.
what advantages does it have over built in cross overs?

• its stereo. you can run your dual subs in stero if you want, and they would have identical settings, not "close enough" settings.
• you can set up your subs in stereo for the front main channels, and feed them both the same mono LFE channel.
• have the controller do the LFE and main channels mix rather than have the receiver do it. Biggest advantage is that its easier to just turn a knob, than wade through menus on a receiver.
• you can use only one channel and run your subs in mono if you want.
• all the controls are on a proper sized component, sitting in your rack, so you don't have to keep tipping your sub forward and fumble around trying to make adjustments.
• the ability to set high pass and low pass points completely independently
• 0-360° phase adjustment rather than just 0-180°
• ability to find right balance between output and extension. (I've turned it off. two Subtwo i units have all the output I need, even at the flat response setting")

Bottom line, I LOVE mine.
It used to retail for $400 till it went out of production. I have two and am using one. If you're interested in the other, make me an offer. If you want to see pictures, let me know.