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StanleyB
04-02-2009, 10:13
I just got a subwoofer off Dave Cawley for a bit of small change. If I can add: the service from Ms & Mrs Cawley was outstanding and that massive box was packed with such care, many others can learn a thing or two from. Given the silly low price Dave offered to accept for a £1500 pair of speakers (yep, two 12" drivers in one box makes it a pair of speakers:) ) I would advise anyone to have a look at what he is selling. Bargains to be had there folks:eyebrows:.

Anyhow, coming back to the reason for my question: where is the best place you have found to put a 12" subwoofer? I now got 4 pieces of 12" drivers in my front room, which is enough to rival the local dance club. I am currently using them in between the NS1000M. But I am worried about passive bass interaction. So I am looking for a way round this.

STan

Filterlab
04-02-2009, 10:49
Does your sub front fire or floor fire?

StanleyB
04-02-2009, 10:53
Does your sub front fire or floor fire?
Neither:ner:. It's a sidewinder, with dual 180 degrees displaced cones. Kind of like a Harrier jump yet, and that includes air displacement. Look up JBL HT PS300.

STan

Clive
04-02-2009, 10:57
There's no simple answer, it depends on your room and listening position. Ideally measure the effects of differing setups and placement. I suggest you take a look at http://www.xtz.se/omxtz.php?sida=22&eng=true

Filterlab
04-02-2009, 11:26
Neither:ner:. It's a sidewinder, with dual 180 degrees displaced cones.

That's the same thing you monkey! :ner:

I've only ever owned floor firing subs which seem to avoid phasing problems, that's not to say that adjusting the phase isn't worthy though.

As Clive said, it's a tricky thing to advise on as each system and room will perform very differently. Ideally though placement should be as far away from the listening position as possible as the wavelengths are long and need some room to travel. I'd start by placing it between and behind your speakers in the middle and work from there, and possibly with the driver facing the wall or to the left or right. I guess if you could angle the sub so that the driver isn't exactly parallel to the wall it would help to reduce standing waves. I've found previously that in my room a sub works best sitting to the right hand side of the right speaker, but that's just the non-parallel sided shape of the room working for me. The JBL doesn't have infinite variable phase but it still has a selector for 0deg or 180deg, definitely worth experimenting with that.

My tuppence worth. :)

StanleyB
04-02-2009, 11:38
These ones are tad different from any subwoofer I have seen before. Imagine it as two boxes stuck together back to back, with each box having its own driver. So they fire left and right, instead of forward or down. What I get is the forward propagated wave from the NS1000M 12" firing at a 90 degree angle to the subwoofer 12". It's like a sideways collision, which is why I mentioned that they are sidewinders;).
I have reaised the NS1000Ms a bit higher and that seems to have evened out things. I guess I shall have some fun experimenting. It's keeping the picture frames etc stationary that I got problems with as well:scratch:...

Stan

Filterlab
04-02-2009, 11:49
Weird, that's not what I saw on the manual for the model number you mentioned. Is it two subs glued together?

StanleyB
04-02-2009, 12:11
Weird, that's not what I saw on the manual for the model number you mentioned. Is it two subs glued together?
It looks lke that, but isn't. Nice kit. Pictures on the net only show one side of it. That's because both sides look the same.

STan

Spectral Morn
04-02-2009, 12:25
HI Stan


Are both parts active or is only one sub active and the other a passive bass radiator ? Working in a push pull way.

Regards D S D L -----Neil :)

StanleyB
04-02-2009, 12:52
Both are active.

STan

Spectral Morn
04-02-2009, 13:17
HI Stan

Try this...this is the way Rel teach how to set up subs.

Place sub along front wall (where speakers are placed) Place in corner facing (at a diagonal)where you sit so from the front of the sub you are firing the longest distance to where you sit. This gives the bass the best chance of blending. set the crossover to be a little bit above where your speakers are...this allows sub to blend in with speakers bass output. You don't want it to be to close to the crossover point for lowest bass frequencies. So if speaker is say 80hz you set above that figure...not at it.

Pick three pieces of music. One with lots of bass, one with say natural bass (Jazz with a upright bass) and say one with male voice deep.

First set volume of sub (assuming you have set cross over) then play music until you can just hear the sub. Get some one to help you makes this a lot easier. Adjust volume of sub until you are happy. Play music and adjust position of sub from rear outwards until bass is clean (not to much) set volume again if you need to. Then playing the music turn the sub from left to right and vice a versa until you are happy with sound. Imagine a center line on front of sub and use this as the pivot point. You don't want to use a front left or right spike as this will move the position of the sub to much. Once set up adjust all spikes until level and lock of. Re-listen and if okay sit back and enjoy. This is done by ear and should work for nearly all subwoofers.

Regards D S D L---Neil :)

StanleyB
04-02-2009, 13:37
Cheers Neil. Useful guide that. Just what I was looking for.

STan

Spectral Morn
04-02-2009, 13:45
You're welcome Stan

Regards D S D L-----Neil :)

alfie2902
04-02-2009, 16:09
This was something i found on the web a few years ago when trying to set up my Rel. It seemed to work well for me. The storm & strata are downward fireing so this my not work so well for your Duel opposite fireing jobbie.

It's much the same as D S D L wrote but may help:)


""I was prepared for an hour of fuss and fidget, painstakingly taking bass measurements with the old Radio Shack meter and moving things around. Instead, David put a disc in player and instructed Al (the owner) and me to sit down and listen. He used the soundtrack to the movie Sneakers [Columbia CK 53146], but apparently anything with a repetitive low-bass signature will do. From there David simply directed us through the process.

He began with the Storm III in the corner with the most solid walls. He started the music and switched phase between 0 and 180 degrees and asked us to identify which was loudest. We settled at 0 degrees immediately.

Next he began the music again and moved the sub's orientation from front to side wall and asked which was louder. Side wall was noticeably louder.

Now David began to pull the sub out from the corner diagonally, and asked us to tell him to stop when we noticed the sub lock in to the room. This step involves finding the "axial node" of the room, where the bass will be most strongly reinforced and create the greatest efficiency. At this point the sub would again become obviously louder and go deeper. It seemed as if David were hardly moving the unit, but sure enough the change was immediate and obvious. Not only did the bass increase in depth and volume, but also the soundstage just seemed to surround you when the right spot was reached. There was no coaching needed. It was that obvious.

The last step was to adjust the gain and crossover settings. With both dials at their lowest settings, David began to first bring up the gain, one click at a time. As soon as the sub became obvious and seemed to intrude upon the main speakers, David backed off one step. Finally it was time to set the crossover. The REL allows for both coarse (A-D) and fine (1-6) adjustments. When set correctly, the sound between the main speakers and sub will sound seamless, with a deeper and more dimensional soundstage, more precise imaging, and no loss in clarity. David told us it was rare to ever get beyond the A coarse setting, and he was right. Then it was just a matter of moving between the fine adjustments and confirming our selection with a few other recordings. What perhaps amazed me most was the difference in one fine adjustment of the crossover. I’m talking a difference of only 2Hz, yet the change was not subtle. We settled in at 23Hz.

The total time for setup on our first try was about ten minutes. The only tools used were located on the sides of our heads.""

Edit: Just found the link to the original review www.soundstage.com/.../candystore200312.htm

Spectral Morn
04-02-2009, 18:04
Hi Alfie

Yes it is similar but you have put more flesh onto what the REL rep showed me one day. I wrote down what I could remember and kept it simple but your post fills in the extra info that will be of help to all. It should work for front and underneath firing subs. The Rel T series has an active driver and an underside passive one.

As an aside this set up works for REL T and R series subs except with T series were the rep said you don't put in the spikes. Apparently it make the sub to high. I reckon that you could adjust the spikes to be short and lock them off from above the mounting bar. I didn't want to argue with the rep.

Good additional Post.

Regards D S D L----Neil :)