Two LFM-2's or Single LFM-1 EX?

Posted by: Wedge

Two LFM-2's or Single LFM-1 EX? - 12/10/07 03:18 AM

With the current deals available on subwoofers, I was considering getting either two LFM-2's or a single LFM-1 EX, including cables, etc, for very nearly the same amount. I have a RR2150 with my old Boston Acoustic speakers in a living room that is 14' by 16', but one corner of the room opens out into the dining room. This system is just for music in this room. From what I read in the other threads it sounded as if multiple subs might be better/more flexible.
I can put whatever I want in the room (obliging wife), so physically larger subwoofer size is not an issue.
Does anyone have any advice?
Cheers.
Posted by: psyprof1

Re: Two LFM-2's or Single LFM-1 EX? - 12/10/07 09:57 PM

For someone in your enviable position (not me alas) the significant factor might be your listening tastes. I don't know how important the near subsonic is for HT experience, but the only musical instrument that produces sound in the range that the LFM-1EX can cover more than the LFM-2 is the pipe organ. So if you're a pipe organ fancier - I am - the choice becomes obvious. I have also heard, but by word only, that reproducing capability below 30 Hz can give a more convincing sense of the size of the recording venue. Of course if you're mostly into HT little of this matters.
One other point: it's said that hearing is nondirectional in the bass, but I'm still more comfortable with a stereo system that keeps the two channels separate all the way down. That means using two LFM-2's as long as each gets its own signal in stereo.
Posted by: Wedge

Re: Two LFM-2's or Single LFM-1 EX? - 12/11/07 05:32 AM

Thanks for your input. The Outlaw manual mentions using two subs and using a "Y" cable to split from the subwoofer output, so I assume both subwoofers would then be getting an identical signal. What you are saying is that it would be preferable to actually wire each subwoofer by routing the left or right speaker cables through them (eventually to l/r speakers, respectively). Is that right? (There is only one sub out line on the RR1250)
Posted by: mahansm

Re: Two LFM-2's or Single LFM-1 EX? - 12/11/07 03:15 PM

My preference would be to split the subwoofer output from the RR1250. This will allow shorter cable runs to the mains without the two extra sets of connections (input/output per line) in the run. This will give better sound from the main speakers.

This will also allow you to roll off the low end response of the speaker to match the subwoofer using the bass management of the RR1250.

One additional benefit is that the internal amplifiers in the receiver will no longer be required to provide power in the bass region, allowing higher output at the higher frequencies delivered to the main speakers.

When I get home tonight I'm replacing my LFM1 + with a pair of LFM1-EX that are now sitting in my kitchen. I might just try the system with all three, although the LFM1 + will be leaving the main system (destination currently not determined). They will be fed from the single channel subwoofer output on the pre-pro.
Posted by: lanion

Re: Two LFM-2's or Single LFM-1 EX? - 01/08/08 05:13 PM

I just got an LFM-2 for my music system, which is in a much larger room than my LFM1-EX and from first impressions the LFM-2 is no slouch! It is very deep and musical. It passed the Massive Attack test with flying colors (my Totem Hawks were not up to bass-y electronic music).
Posted by: mdrconsult

Re: Two LFM-2's or Single LFM-1 EX? - 01/08/08 07:26 PM

Wedge,

I looked at the manual and you might be able to do a little trick if what you want to do is get true left and right sub signals. Instead of running a Y splitter from th sub out which will get you the same signal to both subs you could use the tape out jacks (which is similar to the pre-out and can be connected to the "sub in" on your subs) to drive the left and right subs. Of course this assumes that you are not using the tape out. The tape out signal will not have any bass management applied to it so you will be receiving the full left and right signals on those lines. You will need to use the crossover circuit on your sub to keep from driving the sub at to high a frequency. This setup will still allow you to use bass management if needed on your main speakers.

I have not personally tried this but I believe it will work. The manual makes reference of this technique (see page 16 option 4) for driving a second set of speakers with an external amp. Well, that is exactly what two powered subs would be. Please let us know how this works for you.

Good Luck
Mark D. Rodriguez
Posted by: Altec

Re: Two LFM-2's or Single LFM-1 EX? - 01/08/08 07:58 PM

Quote:
Originally posted by psyprof1:
For someone in your enviable position (not me alas) the significant factor might be your listening tastes. I don't know how important the near subsonic is for HT experience, but the only musical instrument that produces sound in the range that the LFM-1EX can cover more than the LFM-2 is the pipe organ. So if you're a pipe organ fancier - I am - the choice becomes obvious. I have also heard, but by word only, that reproducing capability below 30 Hz can give a more convincing sense of the size of the recording venue. Of course if you're mostly into HT little of this matters.
One other point: it's said that hearing is nondirectional in the bass, but I'm still more comfortable with a stereo system that keeps the two channels separate all the way down. That means using two LFM-2's as long as each gets its own signal in stereo.
I'm a big proponent of using subs in stereo, and have recorded pipe organs with 32 foot ranks to specifically display the benefits in realism provided by this setup. Any recordings which use simple, "purist" microphone techniques, especially those which use spaced omni-directional mics, will have the capability to contain significant low frequency ambience cues.

I used to have a thread here discussing stereo subwoofers, but if it can't be found, here is another place where it can be accessed.

Stereo Subwoofers
Posted by: mahansm

Re: Two LFM-2's or Single LFM-1 EX? - 01/08/08 07:59 PM

Mark,

One problem with your approach is that the volume control does not affect the tape out jacks so that level matching would only be correct for one setting of the volume control. You could split the preamp outputs, sending one run to the amplifier and one to each subwoofer. You would not be able to use the bass management in the RR2150 but could setup the crossover on the sub to match the natural rolloff of the speakers as closely as possible. In addition, you can use the volume pots on the subs to do level matching.
This would allow true stereo subwoofers without purchasing any additional electronics.
However, since most deep bass appears in both channels, I'd still prefer to run the mono sub out signal to the pair of subs (as I have done in my system).