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Lowther Bass Reflex and Subwoofers

Well, after reading about how difficult it is to marry a subwoofer and single driver speakers I think I now understand what all the fuss is about.

My speakers are Lowther DX2 in a Lowter America 2.5 I bass reflex cabinet. The subwoofer is a REL Strata II. A quality 300b SET interstage coupled amplifier is the power. Primary music is diverse; jazz, rock, reggae, classical, indian. Most of the mate rial is acoustic and some with very high dynamic range.

The REL is set on third position for both crossover (fine, coarse) settings which is around 60hz. The REL is driven with speaker level via the standard Neutrik connector.

I was listening to material with pretty good dynamics the other night; ie, Shakti, Roger Waters In The Flesh, Bob Marley Survival. There was just no bass impact on the bottom to speak of. When I walked over to the woofer there is all sorts of low end energy happening. Sitting in the sweet spot of the Lowthers and it just sounds kind of muddy.

The Lowthers are placed about three feet from the rear wall and one is near no side wall; the right speaker is three feet from a side wall.

My understanding is this REL is one of the better subs out there for use with "quick" speakers. Might it be that I just need to spend more time with crossover points and positioning of the Lowthers? The sub is to the left of the system; ie, about one foot to the left of the left Lowther and two feet from the rear wall.

The walls and ceiling are bare at this point as I just moved in. I am just about ready to acquire another woofer, or two, to audition. Some of the woofers I've been considering are the Magelland and the PMC. I'd like to find an older Hsu 8" passive woofer and run an active crossover but I have never seen one for sale.

Advice?
c123666
8 responses Add your response
johnk's avatar
johnk
1,975 posts
 
Swarms a good option as suggested or a proper cabinet for the Lowther ported that's really not the best way to do this.
atmasphere's avatar
atmasphere
11,841 posts
 
The thing about full range drivers is that they aren't.


So if you want to really have fun with them a sub system is a good idea. To that end you might want to look into the Swarm by Audiokinesis, since it can do an excellent job of integrating. The subs are small and meant to be placed directly against the wall. There are four of them; they are meant to be placed asymmetrically in the room. In this way they can break up standing waves in the room, giving you uniform bass to 20Hz without drawing attention to themselves (both sonically and visually). To that latter bit, they should not be run above 80Hz. 80Hz and below is the frequency at which the human ear detects bass only in an omnidirectional way. Its harmonics of the bass instruments that will be played in your Lowthers, causing the soundstage.


The Swarm subs are 1 foot square and 2 feet high; fairly small as subs go yet they go to 20Hz as they are meant to take advantage of the room boundary effect. IOW you can't do the same placement with regular subs as they will draw attention to themselves if placed against the wall, making integration very difficult!


The Swarms have received three Golden Ear Awards, well deserved.
hifidream's avatar
hifidream
135 posts
 
To make some good WAF I made two of my subs into end tables. It’s amazing what a 1” thick piece of glass and a lamp will do you hide them. Most people have no idea they are speakers. :)
hifidream's avatar
hifidream
135 posts
 
Subwoofers are hard to integrate because of the length of the waves, 25-50ft and that wave is bouncing around the walls making peaks and nulls like water drops in a pool of water in a box (this is why reversing the polarity doesn’t help, it’s the same wave off axis). You may find a great spot for it that works with your room (it won’t be near a corner) but if you still have trouble you should consider a sub array.

 Four subs can use each other’s waves as the vehicle to do DSP room correction. If you use an active crossover like a mini DSP with a high quality microphone to measure the room with Room EQ Wizard you can add the data into Multi Sub Optimizer (both programs have suggested donations and I used their tutorial with my own data) which will give you the data to make custom crossovers (each sub needs its own channel/amplification) in your mini DSP. Copy past them in and you’ll have full range music bliss. Just need to adjust the volume of the subs vs the mains till they disappear. No muddy base, fully integrated, no angry wives or neighbors. It’s work but anything worth having is. . . 
c123666 OP
871 posts
 
I think I found a solution and from an unlikely source. First, these speakers don't go down to 40 when they are 3' from the walls which is how they are set up as this presents the most neutral sound albeit at the expense of a bit of bass.

I'd picked up a Gallo 8" passive sub to throw into the home theatre system but the lady said NO and that was that (already one powered woofer). So, I moved it into the stereo system and ran a RCA cable from the output of the preamp in parallel with the RCA to the SET 300B amplifier into a Creek passive preamp. This then feeds a Bryston 2BLP 60wpc SS power amp; the creek provides the volume control. The Gallo has an internal passive crossover that is crossed at 120hz; I did not think it would work well at all. BUT IT DOES! The Gallo is 8 ohms and low 90s for efficiency so the Bryston works quite well with it in stereo mode running into the sub inputs.

I reset the REL Strata II to cross over at the mid 30s. So, the REL works the sub bass and now sounds fine; the Gallo works the midbass from around 35, or so, up to 120. The lowthers do the rest. The REL is set to reverse phase.

It sounds great; bass is tight and well defined. The remote controlled Creek allows the mid bass to be changed easily for each recording.
gmood1
1,251 posts
 
I've been reading the 2.5 I has a in room response down to roughly 40 Hz.... Minus 3 or 4 dB. Your subwoofer crossover may actually be set a little too high at 60 hz. Just a thought.
With patience it will come together for you.

Good luck!
c123666 OP
871 posts
 
I've tried the phase repeatedly; makes a subtle difference but that is not the issue. Perhaps I need to rearrange my system so I can move the Lowthers closer to the rear wall to increase their bass output and then try to integrate the REL again.
gmood1
1,251 posts
 
Try running your subwoofer 180 degress out of phase. Also you may want to check the volume of the subwoofer with a SPL meter to see if you have it set too high.You should not be able to locate that sub in the room when it's set properly.
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