Is time-aligning MBM-12 with true sub a must?

[OU812]

Hello,

I recently purchased a MBM-12 to match with my VTF-3 HO/Turbo. After unpacking it, hooking it up, calibration to match true sub and speakers, and setting the phase, I am really pleased with the mid-bass boost my system got.

The only thing missing is time alignment with the true sub.

Is this a must in order to squeeze every bit of performance from the MBM-12/VTF-3 HO combo?

If so, which is the "digital delay box" recommeded?

[Pete_Hsu]

Hey OU812,

I don't think that time alignment is really a must, as we have been using such a system for years without it and have always had great results. That said, if you would like to experiment with it, I would recommend something like Behringer DSP2024P, which is available online for about $100 from places like American Musical Supply.

Sincerely,

[mojave]

The only thing missing is time alignment with the true sub.

Is this a must in order to squeeze every bit of performance from the MBM-12/VTF-3 HO combo?
If the frequencies at the crossover point are not arriving at your ear at the same time they will either cause addition or cancellation of these freqencies. This results in an increase or decrease in SPL at the crossover frequency. Therefore, you need a method of setting delay in order to maximize the performance of your subwoofers/speakers.

You can get close by measuring the distance between your subwoofer and MBM-12, but for the best accuracy you should use a computer measurement program such as Room Equalization Wizard (REW).

I have a MBM-12, VTF-2, MK3, and two Buttkickers. I decided to get a Behringer DCX2496. It costs about $280 plus more for the cables and sound pressure meter or microphone. I feel that it has improved the sound of my system and made the bass tighter. In addition to delays, you can perform digital crossovers between the MBM and sub, parametric equalization, and you can save multiple configurations for testing purposes.

I orginally set it up using a Radio Shack sound pressure meter and REW software. I now own a measurement microphone, but still need to get a mic preamp before I can redo my calibration. There are many things I still want to try.

There are recent more threads at HomeTheaterShack.com that discribe how to use REW to set delay and phase. I would like to try to implement some of the suggestions when I have time.

[mojave]

I don't think that time alignment is really a must, as we have been using such a system for years without it and have always had great results.
I agree that you can have great results without time alignment. There is a lot about sound that is subjective and many people don't notice differences that others will notice. If someone was to ask me if it was better to have the sub and MBM-12 equal distance from the listener, or have the MBM-12 placed nearfield, I would choose nearfield placement over correct time alignment/flat frequency response. The benefits of the impact provided by nearfield placement outweigh any problems caused by time alignment, in my opinion. Especially if you are using it for movies rather than music.

With that being said, if the goal is to have a flat frequency response, then it becomes imperative to measure your system and it might be necessary to provide delays and equalization.

There are many reasons why we spend time and money on sound. I would say that if you listen to music critically, then you should consider calibrating your system the best way possible. However, if most of your music listening is casual, like while reading a magazine or cooking :D , then you probably don't need to have the flattest frequency response.

[Pete_Hsu]

I completely agree with you mojave. The MBM, whether time aligned or not, improves performance in so many different aspects that it more than offsets any potential drawbacks. Placing the module close to the listening position often leads to a flatter/smoother mid-bass response vs using a deep bass subwoofer up front to handle low/mid/upper bass. The close proximity to the listening position also heightens impact and reduces distortion for a given listening level. Also, having a unit dedicated to mid-bass duties reduces intermodulation distortion and increases dynamic range. These are all huge benefits in favor of systems with MBM-12.

[OU812]

I have it located next to my primary listening spot. X-over at 80Hz, it doesn't call any attention to itself, even at reference levels. There is a certain "evenness" to my system's bass performance now that wasn't there before.

Don't get me wrong, I would have been happy if I was destined to stay with just the VTF-3 HO/Turbo by itself, but at certain frequencies in my room (mostly upper bass ones, or so it appears...), the HO was a bit of a brute. Now with the MBM-12 handling everything betweem "50Hz and 80Hz" and the HO handling everything "<50Hz", the bass spread throughout the room is more even, tighter and it appears that I have endless headroom.

-Luis

[Bori]

When using dual 3.3 Subwoofers w/o turbo along with the MBM-12, can you run the dual subs at Max ext. or should I just leave them at Max. out?

[cacihome]

When using dual 3.3 Subwoofers w/o turbo along with the MBM-12, can you run the dual subs at Max ext. or should I just leave them at Max. out?

I think...If you hace the MBM-12, but 3.3 with no Turbo, use your dual subs in max output...You will have insane headroom in the 18hz-80hz

However, buy the turbo since you will move nearly 2x more air with each one and then use it in max extension w/ Turbo!!!
So with turbo you will move air nearly as 4 of them vs regular extension with port plug...

[n737nc]

I think...If you hace the MBM-12, but 3.3 with no Turbo, use your dual subs in max output...You will have insane headroom in the 18hz-80hz

However, buy the turbo since you will move nearly 2x more air with each one and then use it in max extension w/ Turbo!!!
So with turbo you will move air nearly as 4 of them in the regular extension with port plug...

Are you saying to use the 3.3 w/Turbo in max extention mode with 1 port plugged? I didn't think that was advised by HSU? I didn't think you could plug 1 port while using the Turbo?


Nick

[cacihome]

Are you saying to use the 3.3 w/Turbo in max extention mode with 1 port plugged? I didn't think that was advised by HSU? I didn't think you could plug 1 port while using the Turbo?


Nick

Sorry if I explained myself wrong there...TO clarify things...

You can use the maximum extension tuning either with Turbo or by using the port plug...
All I was saying to you is : buy the Turbo so you can run the 3.3 in max extension and you will not sacrifice low extension output(as happens when you use the port plug)...
If you use the port plug with the TUrbo that would tune the cabinet even lower and it is not recommended by Dr. Hsu.

[n737nc]

Sorry if I explained myself wrong there...TO clarify things...

You can use the maximum extension tuning either with Turbo or by using the port plug...
All I was saying to you is : buy the Turbo so you can run the 3.3 in max extension and you will not sacrifice low extension output(as happens when you use the port plug)...
If you use the port plug with the TUrbo that would tune the cabinet even lower and it is not recommended by Dr. Hsu.


Gottcha ;)
You kind of confusted me a bit :D

[cacihome]

Gottcha ;)
You kind of confusted me a bit :D
I am from Puerto Rico mi amigo...
And I'm practicing my english here,....jejeje:D

[OU812]

I am from Puerto Rico mi amigo...
And im practicing my english here,....jejeje:D

Cacihome,

You no longer own a VTF-3 MK3? If so what are you getting next?

[cacihome]

Cacihome,

You no longer own a VTF-3 MK3? If so what are you getting next?


HUMMMM...

jejeje

I want a 15" or 18" ported sub.....
The castle looks tempting....But I like more and believe more in the Dr's talent for sound...

[OU812]

HUMMMM...

jejeje

I want a 15" or 18" ported sub.....
The castle looks tempting....But I like more and believe more in the Dr's talent for sound...

Are you telling us you jumped into the "Epik bandwagon"? :( Or, is there something you know that the Dr has up his sleeve that you are not telling us? ;)

[Pete_Hsu]

caci hasn't seen anything yet, but he might just see something interesting in Las Vegas next week ;)

[OU812]

caci hasn't seen anything yet, but he might just see something interesting in Las Vegas next week ;)

Oh no, Pete! You just didn't...

Hsu Research is up to something BIG. :)

[cacihome]

Are you telling us you jumped into the "Epik bandwagon"? :( Or, is there something you know that the Dr has up his sleeve that you are not telling us? ;)


I wish I knew more than you OU812, that is why im telling that the castle looks good...

Also, I also said that I trust the Dr. to come with something better...

[Pete_Hsu]

Oh no, Pete! You just didn't...

Hsu Research is up to something BIG. :)

Laughing out loud, yes, I think that 2008 will be a very momentous year for us in terms of new product development. ;)

I don't think caci will be going anywhere other than Hsu Research! :)

[JonnyOzero3]

Laughing out loud, yes, I think that 2008 will be a very momentous year for us in terms of new product development. ;)

I don't think caci will be going anywhere other than Hsu Research! :)

I like the sound of this :)

[n737nc]

Laughing out loud, yes, I think that 2008 will be a very momentous year for us in terms of new product development. ;)

I don't think caci will be going anywhere other than Hsu Research! :)


Now you say that, when I just dumped out $1400 worth of subs :(

[JonnyOzero3]

Now you say that, when I just dumped out $1400 worth of subs :(

That's why the Lords of Kobol created Audiogon :D

[Pete_Hsu]

Now you say that, when I just dumped out $1400 worth of subs :(

I don't think anyone with an HO/t + MBM-12 has anything to really worry about. MBM-12 simply takes system performance to a whole new level in many instances :)

[cacihome]

Laughing out loud, yes, I think that 2008 will be a very momentous year for us in terms of new product development. ;)

I don't think caci will be going anywhere other than Hsu Research! :)


I am here waiting like a good boy!!!

I dont know since we have waited so long, the Dr. may prescribe for me 2 of those monsters....:D And since I am a good patient I will obey my treatment!!!!:D

[bsoko]

My Pioneer '94 does something called "Full Phase Control". I don't know how much this has to do with the LFE, but I have never had any issues with delay when using my 3.3 Turbo (farfield) and my two MBM-12's (co-located, nearfield).

Bill