General Asylum: REVIEW: MJ Acoustics Ref 150 mkII Speakers by astrostar59

Model:	Ref 150 mkII
Category:	Speakers
Suggested Retail Price:	$1400
Description:	Active subwoofer 150 watt mosfet downfiring, 10" speaker.
Manufacturer URL:	MJ Acoustics
Model Picture:	View

Review by astrostar59 on September 12, 2007 at 14:36:03
IP Address: 83.61.211.104 Add Your Review
for the Ref 150 mkII

This is my personal review of the MJ Acoustics Ref 150 mkII.

I have run an Audio Note valve SET system for a couple of years now, having migrated from SS and huge power/speakers to the flea powered world of valve amplifiers and efficient speakers.
So, this review is primary based on observations in my own valve system which consists of components of a pretty high quality to start with.

The sub arrived in substantial box, well packed, and is supplied with: RCA lead (5m), Speakon lead (5m), power cord, 4 x optional floor spikes, manual.

For this review, I set up the Ref 150 to run from the RCA pre-out connection, preferring this to the high level Speakon connection.

Fist thing, power everything off, plan where you are to place the sub and lay out all the connections before hooking up. If you have 2 pre out connections, fine. If not you can buy a simple 2-box RCA connector.

On the back of the Ref 150 are 5 main rotary buttons. Main one is for function selection, the other 4 are for gain and frequency tail off on RCA or Speakon, and 2 more for gain and frequency tail off on LFE (low frequency input from a sub out on an AV amp). This arrangement allows maximum flexibility for either stereo or AV usages.

Next, check the gain is set to lowest setting, -99db, and then slowly raise the volume on the pre amp to a normal listening level. At this point, and after raising the sub gain to in my case -24db you will hear some sub activity. Now the fun starts. Play a CD with a tuneful bass, preferably prominent in the mix. I used a level 42 track. You now will need to play the same track on repeat many times while you start the fine-tuning process. With the Ref 150 you have very sensitive control over actual 1hz steps for the upper frequency cut off. The big digital display on the rear panel shows all the setting, output level, frequency cut off, phase and gain.

My main speakers are good quality Zingali Overture 2's, with horns and 8 inch bass units. I initially guessed the frequency roll off at 45 hz, but quickly realised it needed to be set much higher, bearing in mind the roll of slope is set at 24db cut off at the displayed setting. Thus 60 hz setting starts the roll off at 36hz. After about 2 hours of constant experimentation, I stuck with 86hz. This was producing the best lower bass details and at the same time the mid bass was now merging very closely with the Zingali's.

Next, another 2 hours playing with the gain and also the phase. On phase, generally a down firing sub will need to be set to 90Â° phase to match a forward firing main speaker, which is what I ended up using. Some rooms can alter this a bit, so it is good to have this as a setting.

Now gain. It took quite a while to settle on this. I got a setting on the level 42 track, but when I swapped to another CD, Faithless for instance, or some live Eric Clapton, the mix shifted a bit.

This is where I came to the conclusion I would need 4 presets, mainly for the gain levels. And it comes down to the subject matter. Lets face it, a pumping Faithless disco track will fill a room with a lot of energy, but a live unplugged gig, or some classical not so much. The different gain levels also restored a lot of the atmosphere and subtle lower registers almost lost in the last 2 types of music.

So, enough of the setting up, what the hell did it sound like? Well, I must admit, I am a bit of a bass fan. Sorry, used to be a mobile DJ (not famous far from it). And I have owned many large solid-state amps and big speaker set-ups over the years. What I have finally settled on is a valve system with a CD front end. And I absolutely love it, beautiful midrange, superb treble, micro dynamic, vocals, all the usual valve pros in spades. But I love live music, and my system was lacking that final finish, the ambiance and foundation you normally only get with huge SS amps or crazy priced Â£40K+ esoteric custom set-ups.

This sub was, I admit, a revelation. It was not a one-note boom box, or a muddy rumbling thing in the corner. Technology has moved on so much in the last few years with many subs, and what we have here is a serious piece of true hi-fi sub frequency transducer! I was amazed at the expansion to the sound stage. The ambience was suddenly more natural. The dynamics had moved up, and the extra information I was hearing right down to a true sub 15-13hz was amazing. And a pleasant surprise was the attack and speed of the output. It kept pace perfectly with the Zingali's, showing the speaker to be of very high quality and the on board amp likewise.

My initial reaction on set up was to add bass to the mix, to actually really notice the sub. But this is not the way to go. I found after a dayâ€™s careful adjustment, the best (for my ears) setting was to extend the response, not change the balance. This marriage of the main speakers and the sub system is crucial to create a seamless and realistic sound stage with a full audible frequency response. And the way to test you have got it right, is a few days later, try switching it off while playing a favourite CD, and you will hear exactly what you were missing without it. I for one cannot go back.

Fantastically recommended product and made in Britain to boot!

Product Weakness:	understated lokks, no go faster branding.
Product Strengths:	sound quality easlly high enough for true hi fi stereo applications, flexibility, controls, price

Associated Equipment for this Review:

Amplifier: Audio Note Conquest 300B Mono blocks
Preamplifier (or None if Integrated): Audio Note M3 valve pre amp
Sources (CDP/Turntable): Audio Note CD1 and Audio Note Dac 1.1
Speakers: Zingali Overture 2's
Cables/Interconnects: Audio Note ANV silver
Music Used (Genre/Selections): Pop, Rock, Acoustic, Classical
Room Size (LxWxH): 16 x 12 x 9
Room Comments/Treatments: Large rugs, thick curtains, cork rear wall.
Time Period/Length of Audition: 2 days
Other (Power Conditioner etc.): Mains filter
Type of Audition/Review: Product Owner
Your System (if other than home audition): As above

Amplifier:	Audio Note Conquest 300B Mono blocks
Preamplifier (or None if Integrated):	Audio Note M3 valve pre amp
Sources (CDP/Turntable):	Audio Note CD1 and Audio Note Dac 1.1
Speakers:	Zingali Overture 2's
Cables/Interconnects:	Audio Note ANV silver
Music Used (Genre/Selections):	Pop, Rock, Acoustic, Classical
Room Size (LxWxH):	16 x 12 x 9
Room Comments/Treatments:	Large rugs, thick curtains, cork rear wall.
Time Period/Length of Audition:	2 days
Other (Power Conditioner etc.):	Mains filter
Type of Audition/Review:	Product Owner
Your System (if other than home audition):	As above