Rel Q150E MK 2 setup

Sab

Prominent Member
Joined
Dec 18, 2002
Messages
989
Reaction score
68
Points
343
Location
London
I have just bought myself a new REL Q150E Mk2 subwoofer.

The store I bought it from has given me advice but I am not sure whether they are right. They told me to connect to the +12DB input on the subwoofer and choose slam rather than depth.

I found it sounded better on the 0DB input on the subwoofer.

What is the correct setup?

At the moment I have set my PMC TB2s to large as well as my centre speaker (which is huge).

Is it better to set all my speakers to small and route all the bass to the subwoofer or will this annoy the neighbours?
 
I had the original Q150 and always used the 0db or it sounded boomy, I also always used depth, you get more accurate reproduction that way if not as much volume. It is generally considered best to set all speakers to small and direct all bass to the sub but no doubt some people will argue the point. If you take time to position the sub for the best response and integrate it properly with your mains you will find it a great little subwoofer.
 
There is no standard method that suits all answers. I would guess that seeing your list of equipment you are an experienced listener and if you say that the sub sounds better when connected to the 0db socket - you are probably correct.

Again the business of setting the speakers to large or small is a matter of trial and error. Setting the speakers to small and letting the processor handle all of the bass management is one way but setting them to large and connecting the sub to both the sub output on the processor plus the speaker connections is another.

The second method is much more fiddly to set up but the rewards are said to be greater with the right equipment and if you got a neutrik connector with the sub, all you will lose by trying it out is some of your time.

Give it a go and let us al know the results.
 
I spent 10 minutes on the phone talking to REL before I set up the high level Neutrik Speakon connection.

Settings I prefer for both high level and low level inputs:

1. slam - punchier better for movies. depth is for music.

2. 0 DB . +12DB is too boomy.

3. Set the crossover frequency to 80HZ. This will prevent too much frequency overlap with the low level and high level inputs.

4. Set all three front speakers to large.

Fifteen minutes around the back and with settings will reap benefits as you will need to connect 3 bits of cable to the left and right speaker outputs on the power amp (see manual). The speakers should be connected as normal.

With the high level connection as well low level I noticed that the bass was better integrated with the front three speakers. The bass output was higher but more staisfying. The bass was getting closer to what the recording engineer intended ( this is hard to explain but the sound is more natural.)

So it is better to use the high level connection as well as the low level connection on the REL subwoofers.
 
To find the right volume level between high level and low level :

1. Fist connect the high level interconnect. Play music with lots of bass and adjust the high level volume until it sounds right.

2. Choose setting 2 or 4 on the mode dial in order to bypass the crossover for low level input. This prevents the crossover filter being used twice - once by the processor and again by the sub. Select setting 2 or 4 depending which sounds best.

3. Now connect the low level input and adjust the volume to whatever sounds best. Play a DVD which you know well to help with the adjusting.The high level input should be connected for this as well.

(4. Can fine tune with Sound Pressure Level meter if you wish for the subwoofers ouput by the processor at the end.)
 
Excuse the questions of the newbie, but...

Although i have an electronics background and a reasonable understanding of audio (and im slowly getting there with AV) - i don't understand why you would want to use both the high and low level inputs to an active subwoofer at the same time? (and why the manufacturer would provide this option - set up the input circuits to allow them both to be used at the same time without causing issues, i saw the seperate level controls for the inputs on the pic at link below).

There must be some sound improvement, or further options available by doing this but after reading the posts in this thread i still dont understand how this works or what exactly the improvement might be. It seems to revolve around crossover frequencies and integrating the bass between fronts/sub - but how?

Normally i would expect the differnet inputs to be as follows:-

Low level inputs: Normal connection for signal from a decoder on an AV amp. Crossover can be set up on decoder, or left at a high frequency on the decoder (or bypassed?) and use the sub's built in crossover to fine tune lower.

High level inputs: If you are using traditional HiFi seperates comprising of just the amp and front speakers (no AV amp or crossover path) or if you want to bypass the AV amp decoders crossover(?).

For an AV system (with decoder/crossover) using the high level input would likely give more signal degredation as it passes
through an extra amplifier and then voltage level reduction circuit at the sub input before reaching the sub's own built in amp (although probably too small to notice?).

Can anyone provide any information on this and how/why it works?
Can you do this with any normal high quality active sub, or is it an extra feature on only some sub's?

Cheers, Brimstone (Mark).


P.S. Found this info @ homecinemachoice.com.

(http://www.homecinemachoice.com/tes...ice.com/testbench/Subwoofers/REL/RELQ150E.php)

Connectivity is fairly comprehensive, as is the impressive number of controls on offer. High-level inputs are provided but REL is sticking with an airtight Neutrik Speakon terminal, which means you will have to use the cable and plug supplied. The Q150E does not offer any high-pass filtering, so bear that in mind if you plan to use the speaker hook-up method. Personally, in home theatre speaker systems I much prefer low-level signals since you can use the bass-management in your decoder, and they are accommodated by way of a pair of standard phonos - one of which imparts a 12dB gain if, as unlikely as it may seem, the output of your processor or receiver is insufficient.

Additional controls include a phase switch, an infinitely variable low pass filter (between 26Hz-106Hz), which can be defeated if you're using a decoder crossover, and a control marked 'Slam' and 'Depth'. The 'Slam' position will increase the SPL output between 40Hz-150Hz but at the expense of bass extension, whereas the 'Depth' mode affords maximum low frequency output and a near flat response.

HCC Practical Tip

The Q150E allows high- and low-level connections to be used simultaneously, but in the real world, juggling the two may prove tricky unless you're willing to set your decoder up with large front L/R loudspeakers. Also, be sure that your hardware doesn't send low frequencies to the front L/R loudspeakers and the subwoofer output when listening to matrix or stereo material, otherwise you'll be stuck with unwanted bass doubling.

:confused:
 
Many people using an AV amp will prefer to use direct mode for CD replay but on many amps the direct mode ignores the subwoofer. That may be OK if your main speakers are full range but not if they are satellites as you will lose anything under 80Hz - 100 Hz

Some people also use a stereo amp to drive the main speakers with a processor or AV amp driving the centre and rears and a high level connection will ensure that the subwoofer will work when just the stereo amp is being used.

Thirdly some people will say that the bass sounds better when the sub is connected high and low level at the same time although that is very subjective.
 
Thanks Ian,

I hadn't considered the 1st 2 points relating to different system set-ups.
Makes sense.

The 3rd point was the part that i don't really understand, i guess it must be a bit of a suck-it-and-see option that can be tried (on all dual input active subs?). I'll try and get round to seeing if i can dredge the dreaded web for some manufacturer bumf about it.

Cheers, Mark.
 
I use both the high and low level inputs because my amp will only crossover at 80Hz. By using both inputs I can set my fronts to be 'large' and only have the sub takeover below 50Hz when my fronts roll off.

This means that:

-I can use direct stereo mode and still get output below my speakers normal range.
-There is less load on the sub.
-I feel better because I'm using the full range of my floorstanders all of the time.

I would not use the high level connection if my amp allowed me to set individual crossover frequencies for each speaker.

Ben.
 
Noodle,

Do you need to connect both inputs because your AV amp doesn't give a sub output when in direct stereo source mode?
When running in AV 5.1 mode - how does this then effect the sub when it has x2 sets of input signals from high & low
level connections at the same time?

I haven't had my amp long or had a good look at the manual yet (this is the first time the AV kit has been out of the box, and it isnt set-up properly as im about to move house) but i thought i could choose to still have a sub signal output when in direct mode (mixed stereo signal sent to sub? i have a Marantz SR5400). Is that just a limitation of that particular amp? Perhaps mine just allows it in stereo mode, but not in direct stereo mode (i'll have to check before i box it).

What about for 5.1 AV sound.

"I use both the high and low level inputs because my amp will only crossover at 80Hz. By using both inputs I can set my fronts to be 'large' and only have the sub takeover below 50Hz when my fronts roll off."

For normal surround use - if speakers are set to large (supplied full range signal), AV processor sub cut off set to 80hz, and sub crossover set to 50hz, then the floorstanders will use their full low end potential without interference from the sub anyway. Why would you require the high level inputs connected at the same time for this to happen?

"I would not use the high level connection if my amp allowed me to set individual crossover frequencies for each speaker."

Why? What difference does it make by using the high level connection?

Perhaps there's something im not quite following regarding the sub connections or the crossovers.
I've got a feeling there's something important im missing that will make everything clear...

From Sab's post:-
"Choose setting 2 or 4 on the mode dial in order to bypass the crossover for low level input."

So there's a 80hz cutoff AV low level signal from the AV amp/processor and a high level input from the speakers (amp speaker level output front left and right). Why?.. is this a special feature of this REL active sub only? Nope, still don't get it.

Somebody put me out of my misery and point out what it is im missing.

Yours increasingly confused,

Mark.

:confused:
 
Sorry folks, wish i could express my questions in a short humorous one liner. Mark.
;)
 
Do you need to connect both inputs because your AV amp doesn't give a sub output when in direct stereo source mode?

No, I can elect to have a signal output to the sub in stereo, but: If my fronts are set to large, they have output between 50 & 80 Hz and so does the sub, so it sounds ‘boomy’. If set to small, everything below 80Hz goes to the sub. With the high level connected, and the crossover on the sub set to 50Hz, the sub only takes over below 50Hz.

For 5.1, if the fronts are set to large, a full range signal is sent to them and the HL being connected means that the sub takes over below 50Hz. The low level input means that the LFE channel and the sub 80Hz frequencies from the centre and rears are sent to the sub.

For normal surround use - if speakers are set to large (supplied full range signal), AV processor sub cut off set to 80hz, and sub crossover set to 50hz, then the floorstanders will use their full low end potential without interference from the sub anyway. Why would you require the high level inputs connected at the same time for this to happen?

To avoid the ‘doubling up’ of the 50-80Hz frequencies.

"I would not use the high level connection if my amp allowed me to set individual crossover frequencies for each speaker.
Why? What difference does it make by using the high level connection?"

Because then I could have a 50Hz crossover for the fronts and an 80Hz crossover for the centre and rears.

is this a special feature of this REL active sub only?

Yes, this is a special feature of REL and I believe also MJ Acoustics subs. Setting 2 or 4 bypasses the crossover on the low level input, so you can have for instance a 50Hz crossover on the sub, leaving the amp to control the crossover for the centre and rears.

Hope this helps.

It must also be said that most people are quite happy just connecting the low level and letting the amp do all the work. I am not happy with this for the reasons detailed earlier.

Ta,

Ben.
 
Choosing settings 2 0r 4 bypasses the crossover filter on the subwoofer's low level input to prevent filtering by both the sub and th processor.

Set the rollover frequency to 80HZ on the sub and the processor to prevent doubling of bass - according to the guy in the Technical support- and there will be minimal output form the high level input.

To summarise - the high level input is for music and the low level for DVDs.

I must admit that this is my first REL subwoofer and I have followed the advice from the REL Technical Support guy as I think he knows best.

I am sure some of you out there know more about subwoofers.
 

The latest video from AVForums

Is 4K Blu-ray Worth It?
Subscribe to our YouTube channel
Back
Top Bottom