Ordered MBM-12 to pair with VTF-3 MK2

[RHui_BC]

Finally caved and ordered one... driving all the way down to washington from vancouver, BC to get it...

Wish me luck on integration guys :)

Hopefully, it will be pair nicely with my VTF-3 MK2 to give my theater that nice punch I was always looking for on a budget.

[Pete_Hsu]

Wow, thank you so much, and let us know if we can assist in any way! Hope you enjoy it!

[KC23]

I have been kicking around the idea of getting the MBM-12 to compliment my HSU 2.3.

Anyone out there have this set up going or any set up with the MBM-12?

[RHui_BC]

After 4 hrs round trip and being stuck in traffic corssing the border, being searched, and paying taxes, I finally got my MBM-12. It was a lot lighter than I thought it would be.

First Impressions:
Unpacking it, I felt it was definately cheaper and did not look and feel like a $500 subwoofer...

The sub was light, and was easily moveable. On closer inspection of the sub, they used a coated paper cone, that didn't have a lot of movement... makes sense if you want mid bass.

It came with 2 sets of legs... One for carpet, and I guess the other for harder surfaces... The legs for carpet were plastic cones that screwed in. I was placing the sub on tile, so I wanted to use the other set. It came with these rubber stoppers that had no way of being attached?? I thought maybe double sided tape, but looked in the box and nothing... It looks like I am missing some screws that should have been included for those rubber legs. Oh well, I stuck to the plastic cones.

The $15 sub cable was definately not worth it... the cable is flimsy on first touch, and the connectors were crap. The rubber coating around the cable was incomplete and exposed the shielding in some areas. Once plugged in, it caused my MBM-12 to buzz in certain frequencies. I found out this was caused by the connector being loose... and yes, I tighten the head as much as possible... next up is plyers, but I will probably replace the cable instead.

Placement/Integration:
Summary of my setup...
Denon AVR-2807
JBL 3-Way Bookshelves fronts
JBL Center
Polk Audio Rears.
HSU VTF3 MK2
MBM-12

My room is 15x15x9, and is in the basement... I will draw a diagram later. I placed the MBM-12 as close as possible, which was diagonally behind my primary sitting position.

At first, I left everything the same, and just set the VTF3 MK2 (1-port mode) at 50Hz @ 50% volume with LFE @ -10db and LFE x-over at 80hz. The MBM-12 was set to 10% @ 50hz.
I used master and commander, the first ship battle scene to test. This produced a sound which seemed to be missing a lot of frequencies.. it was dull and boring and not immersive at all, which was expected before tuning. The low freqs were there but nothing really to justify the $500 yet.

After running AVIVA hometheater and messing with the cross over frequencies and level matching the volumes...

I now run:
VTF3 MK2 (1-port mode) @ 57hz at 50% volume,
MBM-12 @ 50hz at 55% volume,
LFE out set to LFE+MAIN @ -12db @ 120hz,
fronts @ 80Hz,
center @ 90hz,
rears @ 110hz.

This resulted in a much fuller and immersive sound, with the impact I was looking for... It's not professionally tuned, and probably needs more work, considering not all frequencies are even.

I replayed Master & Commander this time around, and got a kick from the ship battle. The canon fire was definately felt and not heard, the explosions were existant... but I dont think this was a really good test dvd. I will fool around more on the weekend... I ran out of time and had to sleep. :P

I also tried this chinese music cd which came from an excellent recording soruce. The sound was impressive... the mbm-12 did not add a boomy bass, it was tight and gave accurate reproduction of the bass drum hits. I can say now that my hometheater can be musical.

Conclusion:
Overall I think the MBM-12 is a poor mans solution to get the mid/low bass impact that you would get with huge and expensive tower speakers.

Is it worth the $500usd? It sure doesn't look and feel like a $500usd sub... But it was either that or spend $800-1200bux on tower speakers. So, yea, It was worth $500usd... Integration was a bitch though, and will probably be doing integration for the next month or so as I try different movies and cds.

[tractng]

Very good review. I might be picking up the mbm next week. Just pick up the HO today:p .

Please give ur opinions after further testings.

Tony

[KC23]

Thanks much. I'll be looking forward to your continued review. Not sure This is gonna be for me though.

[frank308]

I believe the mbm-12 has a fairly pronounced roll-off below 50 hz, so if you set the crossover at 50 hz, you don't give it much to work with. I would try setting your VTF3 at 50 hz, and the MBM at "out" and let your receiver determine the upper level.

Frank

[mojave]

There are several changes that I think you should make to your setup.

1. As Frank mentioned, if you have the crossover set at 50 Hz on the MBM-12 you are filtering out frequencies above 50 Hz. Since it doesn't play below 50 Hz, you are playing exactly nothing with the MBM-12. Its crossover should be set to out.

2. You should not cut the LFE signal by -12dB. Instead set it to zero and use the volume controls on the MBM-12 and VTF 3.2. You have to set them independently anyway. Your volume is currently turned too high on the MBM-12 and VTF 3.2 and doesn't leave you enough headroom.

3. When setting up my VTF 2.3 and MBM-12, I found that I needed to cross frequencies slightly. However, I had to use Room Equalization Wizard (REW) to determine the proper frequency. Using Avia is generally not accurate enough to decide that you will use 57 Hz on the VTF 3.2 instead of 50 Hz because you can't really track the decible changes over a given frequency range. If the crossover points don't match, you could get too much of a boost or the frequencies could cancel and give you a dip in frequency response.

4. With your current setup, you are attempting to use the MBM-12 for frequencies up to 120 Hz, the fronts for 80-120 Hz, the center for 90-120 Hz, and the rears for 110-120 Hz (of course the speakers also go higher than 120 Hz, too). By having these four different crossover points you can end up with worse sound per this article at Secrets (http://www.hometheaterhifi.com/volume_9_3/feature-article-multiple-crossovers-9-2002.html). I would suggest that you use 120 Hz for all speakers. This is actually the same frequency that I use.

Here is my recommendation:

Denon AVR-2807: Set the subwoofer to LFE and all speakers to small. Set the crossover for all speakers to 120 Hz. Set your channel level for the sub to 0.
MBM-12: Set the crossover to out. Adjust the phase later.
VTF 3.2: Set the crossover to in with a crossover of 50Hz. Adjust the phase later.

Level match all speakers first using Avia. Now level match your front speakers to the MBM-12 using a tone at 120 Hz. Switch the phase from 0 to 180 on the MBM-12 and use the setting that gives you the highest volume at 120 Hz.

Using just the VTF 3.2 and the MBM 12, level match the VTF 3.2 to the MBM-12 using a 50 Hz signal. Switch the phase from 0 to 180 on the VTF 3.2 and use the setting that gives the the highest volume at 50 Hz.

For fun you can turn off the MBM-12 and switch the crossover on the VTF 3.2 to out. This will allow you to quickly evaluate the difference that the MBM-12 makes in your system. Of course the VTF 3.2 won't play all the way up to 120 Hz, but you will get the feel of things for frequencies from 50-100Hz.

[RHui_BC]

thanks mojave, I'll try that this weekend once I get a spl meter...

Just wondering, but doesn't setting the crossover for fronts, center and rears at 120hz, kinda defeating the purpose of buying good fronts,centers and rears? Does it matter if my speakers are all different sizes, make and brands? Won't this be harder to integrate?

Also,
Do you guys know how this SPL meter rates? my little cousin just destroyed my radio shack on this weekend... and there are no more radio shacks in canada :(.

http://www.thesourcecc.com/estore/Product.aspx?language=en-CA&catalog=Online&category=SoundMeters&product=1219799