Now Original Subs

Mike-48 · « **on:** 19 Dec 2005, 07:19 am »

I am considering a pair of New Original Subs to mate with my system, based around a TacT 2.2X and pair of Revel Ultima Studios. I have never been able to get the bass right in my room and am going to give corner woofers a try. The crossover will be handled digitally by the TacT, which can also do time alignment and frequency-response adjustments. I anticipate crossing over around 200 Hz, because there are presently bass nulls at about 150 Hz.

The obvious choice for woofers would be TacT's own W210, but the VMPS are considerably less expensive, and of course I am aware of VMPS's great reputation.

My main interest is classical music, so good timbre reproduction is important. I do listen to organ music, but much more to opera, symphonies, and chamber music. Any product that will unnaturally thicken male voices, for example, would be a problem.

Any comments from those using this model would be helpful, as well as from anyone with an opinion of how the setup might work.

Thanks!

warnerwh · « **Reply #1 on:** 19 Dec 2005, 07:48 am »

I believe you'd be looking at the 215 subs which replaced the New Originals. These newer models have a 15" active driver. Also please be aware that Vmps now offers built in amps with their subs.

As for sound quality the depth, power and articulation are outstanding, especially considering the cost. Brian has been getting praise for his bass for over two decades and it's well deserved. I'm a bass lover and power and quality are extremely important to me.

ctviggen · « **Reply #2 on:** 19 Dec 2005, 04:28 pm »

Does the TACT sub include an amp? VMPS does not, which increases the real price of the sub as compared to subs already having an amp. Are you sure you want to crossover at 200 Hz? You could have voice in your subs, which I would think would be strange. Are you also sure this is a room mode? According to: http://www.revelspeakers.com/products/specs.asp?ID=2, the crossover frequency is 220 Hz; perhaps this is crossover related? To test, move the microphone about 1.9 feet (approx.), which should be a high point in the axial room mode for 150Hz (see: http://www.mcsquared.com/modecalc.htm). If the mode disappears, it's a room mode; if not, it might be a crossover issue.

As for doing this, I think Zybar has done this (using TACT with subs) at one time. I use subs to supplement the bass on my Rm40s, although my bass amp (QSC) has been broken for a while now and I've been using only the RM40s for bass. Also, if you do get an amp, I do not recommend QSC -- the fan is way too loud and must be replaced (unless you keep your componentry in a different room, that is).

By the way, I've always like the looks and performance of Revels.

ScottMayo · « **Reply #3 on:** 19 Dec 2005, 05:39 pm »

The 215's should do nicely.

Is your room treated? Bass problems can be helped with the right configuration. You might not need to corner load the subs...

zybar · « **Reply #4 on:** 19 Dec 2005, 07:03 pm »

I did indeed use a pair of Larger subs with the RM 40's. With that combo I was able to blend the subs seemlesly and it did help the bottom end out. I was able to do this by keeping the sub crossover at 80Hz or below. Anything above that didn't produce good results (i.e. easy to locate the sub, muddied the midrange, etc...)

I would in no way recommend that you run the subs anywhere near 200Hz.
Personally, I am not sure you really need to cross over the subs so high, but if you do I would look elsewhere. The TacT subs ARE designed to go up to 200Hz and beyond so that could indeed be a better choice.

Rather than suggest other alternatives in the VMPS forum, feel free to PM me for some possible alternatives.

George

ctviggen · « **Reply #5 on:** 19 Dec 2005, 07:16 pm »

Oh yeah, I got the 1.9 feet through the following method. Every lamba/2 should be a peak or a null. If you're experiencing a null at 150Hz, that's a lamba (wavelength) of 7.58 feet, using wavelength = 1137.3 ft/s (speed of sound) / 150 Hz. 7.58/2 = 3.79 feet, which means that every 3.79 feet you should get a null. If you move the microphone half that distance (1.9 feet), you should get a peak.

ctviggen · « **Reply #6 on:** 19 Dec 2005, 07:22 pm »

As for TACT subs being designed to go to 200 Hz, what about them (as compared to the 215s) makes them better at 200Hz than the 215s? According to:

http://www.audiocircle.com/index.php?topic=19570

The 215s have a Frequency Response: +0, -3dB, 18Hz to 200Hz (19Hz with optional Megawoofer). Personally, I think that going to 200Hz on a sub is a bad idea, especially given that the Revels cross over at 220Hz.

zybar · « **Reply #7 on:** 19 Dec 2005, 07:31 pm »

The TacT subs were designed to be corner loaded and crossed over above 300Hz to mate with their monitor speakers.

I am not sure if TacT still sells them, but here is a link to a person who builds them in the US:

http://cls.audiogon.com/cgi-bin/cls.pl?ampstran&1139272721

Here are some stats:

Selected W210 specifications from the brochure:

Frequency Response: 16hz-350hz, Sensitivity 98db (2.83V, 1m), Nominal Impedance: 8 ohms, Maximum SPL: 120 db, Recommended amplifier: 50-150 watts, Drivers: 2 x 10", Bass reflex tuning frequency: 28hz

I am in no way affiliated with the person advertising the subs, not have I heard them

George

ScottMayo · « **Reply #8 on:** 19 Dec 2005, 07:42 pm »

Quote from: zybar

The TacT subs were designed to be corner loaded and crossed over above 300Hz to mate with their monitor speakers.

Yeeesh. Not to bash, but cramming subs into the corners will certainly dictate where you sit, because it's going to maximize room modes. And at 300Hz you'll be able to pick out the sources. I can see why all this might work as part of a dedicated speaker system, designed around these issues, using dedicated electronics, but mating them with arbitrary speakers and electronics (no matter how good) sounds like asking for trouble. YMMV. If you go that route, make sure you have the option to return the subs if it doesn't work out.

zybar · « **Reply #9 on:** 19 Dec 2005, 07:50 pm »

Quote from: ScottMayo

Yeeesh. Not to bash, but cramming subs into the corners will certainly dictate where you sit, because it's going to maximize room modes. And at 300Hz you'll be able to pick out the sources. I can see why all this might work as part of a dedicated speaker system, designed around these issues, using dedicated electronics, but mating them with arbitrary speakers and electronics (no matter how good) sounds like asking for trouble. YMMV. If you go that route, make sure you have the option to return the subs if it doesn't work out.

Scott,

Since the original poster already has a Tact preamp, the corner loaded subs will work fine in the configuration he is asking about. This is part of what the TacT product does.

Starting off your reply with "not to bash" and making a comment that doesn't take into account what the original poster asked about certainly seems like bashing to me.

George

warnerwh · « **Reply #10 on:** 19 Dec 2005, 08:11 pm »

Imo putting the sub in the corner is the best place. I'm using a Behringer DEQ 2496 to tame the room even though it already has three large bass traps. The integration is perfect as you can never locate the sub. Getting rid of the horrible room issues in the bass region with the Behringer is a piece of cake. I'm sure the Tact could even do better as it has been designed deal with the subs in the corner. Loading the room from the corner maximizes the subs performance. It's of course important that you deal with those nasty peaks and dips to properly utilize corner loading. Once done though the bass response is fantastic.

Mike-48 · « **Reply #11 on:** 19 Dec 2005, 11:26 pm »

Quote from: warnerwh

I believe you'd be looking at the 215 subs which replaced the New Originals. These newer models have a 15" active driver. Also please be aware that Vmps now offers built in amps with their subs.

As for sound quality the depth, power and articulation are outstanding, especially considering the cost. Brian has been getting praise for his bass for over two decades and it's well deserved. I'm a bass lover and power and quality are extremely important to me.

Thanks for the information. However, I'm not sure that 15" is better in my application, where I want to cross over fairly high in frequency, using the corner speaker as a woofer, not a subwoofer. Good to know, though, that product design has changed -- although the Web site has not.

Mike-48 · « **Reply #12 on:** 19 Dec 2005, 11:29 pm »

Quote from: ctviggen

Does the TACT sub include an amp? VMPS does not, which increases the real price of the sub as compared to subs already having an amp. Are you sure you want to crossover at 200 Hz? You could have voice in your subs, which I would think would be strange. Are you also sure this is a room mode? According to: http://www.revelspeakers.com/products/specs.asp?ID=2, the crossover frequency is 220 Hz; perhaps this is crossover related? To test, move the microphone about 1.9 feet (approx.), which should be a hi ...

Thanks for the comments.

The Tact woofer has neither a crossover nor an amp. I have an old Carver 1.5t that I plan to use for driving the woofers.

Yes, it is a deep room node, and I have been unable to get rid of it within the limits of acceptable positioning of speakers and ears. The Revel speakers are in theory (and in practice in some other rooms) quite flat, and bass is more even in some other parts of the room.

Mike-48 · « **Reply #13 on:** 19 Dec 2005, 11:32 pm »

Quote from: ScottMayo

The 215's should do nicely.

Is your room treated? Bass problems can be helped with the right configuration. You might not need to corner load the subs...

Thanks, Scott. The room is extensively treated with a pair of cube traps and numerous acoustical panels. That was done before getting the TacT preamp, and it helped astoundingly, mainly with articulation. The TacT preamp adds to that. Still, I've never been able to get the bass in the room the way I think it should be.

Maybe it is leaking out through the glass doors of the fireplace.

warnerwh · « **Reply #14 on:** 19 Dec 2005, 11:45 pm »

Mike: All rooms have peaks and nulls in the bass region. This depends on the dimensions of your room. I too have a fully treated room and the DEQ 2496 helped significantly so I'd expect the Tact to do even better as I think it can adjust for time.

If you could explain why you need to cross over so high it would help us understand your problem better. Any sound above about 80hz can be located by the ear so no matter what sub you use this will be an issue. If you have to cross that high you may want to consider a different speaker.

Mike-48 · « **Reply #15 on:** 19 Dec 2005, 11:46 pm »

Quote from: ScottMayo

Yeeesh. Not to bash, but cramming subs into the corners will certainly dictate where you sit, because it's going to maximize room modes. And at 300Hz you'll be able to pick out the sources.

Scott, If you read Robert Greene's article on this setup in the latest Absolute Sound, you'll get an idea of the theory and practice behind the idea. Robert Harley also describes his experience with it, and I have heard from others in the TacT group who find it a superb way to get realistic sound.

On placement of woofers in corners, you may want to take a look at this page, among others:

http://www.sonicdesign.se/subplace.html

Regards,
...Mike

Rocket · « **Reply #16 on:** 19 Dec 2005, 11:48 pm »

Hi Guys,

Always wanted to ask this question.

How do you hook up a subwoofer to your system? Silly question but i've never used one.

Although the vmps subwoofer is passive does it have a volume control to adjust the level of bass?

Regards

Rod

warnerwh · « **Reply #17 on:** 19 Dec 2005, 11:51 pm »

If you use an amp with level controls for the sub you can adjust it that way. You just use RCA interconnects to the amp powering the sub. Vmps now offers a quality plate amp that has level controls, adjustable crossover and a parametric equalizer built in. This makes it as simple as can be.

Mike-48 · « **Reply #18 on:** 20 Dec 2005, 12:03 am »

Quote from: warnerwh

Mike: All rooms have peaks and nulls in the bass region. This depends on the dimensions of your room. I too have a fully treated room and the DEQ 2496 helped significantly so I'd expect the Tact to do even better as I think it can adjust for time.

If you could explain why you need to cross over so high it would help us understand your problem better. Any sound above about 80hz can be located by the ear so no matter what sub you use this will be an issue. ...

Thanks for the comments and asking some good questions.

I believe I understand the basic acoustics. That rooms have peaks and nulls that depend on their dimensions and position of the speakers is a given. It also is well known that corner placement, by exciting ALL room nodes, results in the most even in-room response. However, putting the main speakers in the corner is not so good because it ruins the imageing due to unavoidable reflections. Thus, the idea of putting the woofers in the corner & the mains in the room.

I want to crossover so high because, with any acceptable main speaker position, I get a null at about 120Hz, which is undoubtedly a room effect, as you say. Since I can't knock down the room, I need to try something else! The TacT is very good at improving such situations, but since nulls are caused by positioning, rather than lack of radiated power, it is rather futile to try to fill them in.

It has been found by TacT and TacT owners that if good woofers are placed in the corners a relatively high crossover can be used to even out the bass response and the woofer will be undetectable as a separate unit. What makes that possible is adjustment within the TacT preamp to delay the main sound as needed so it aligns in time with the woofer sound. It probably also helps to have a good crossover implemented in the digital domain.

Some interesting questions have been asked: is there anything special about the TacT woofers (W210) that makes them more suitable for a high crossover than most 10" or 12" drivers? The response curves of most of the latter I've seen are pretty flat up to 300 Hz or above.

As to exact xover frequency, because it's done in the digital domain, it's easy to experiment and try different ones.

Have I explained the situation better?

...Mike

Mike-48 · « **Reply #19 on:** 20 Dec 2005, 12:09 am »

Quote from: zybar

The TacT subs were designed to be corner loaded and crossed over above 300Hz to mate with their monitor speakers.

I am not sure if TacT still sells them, but here is a link to a person who builds them in the US: [...]

George,

Yes, the link you gave is the sole source of TacT woofers in the U.S. The dealer sells them for less than TacT did, and with return priveleges, to boot. They are the obvious choice for my application, but given their cost, I thought I would investigate other options before making a decision.

...Mike