Here I am being a pain in the a.. again.

I have a dedicated HT room that is 25' long 11' wide with 6'.5" a ceiling.
I have Def-Tech 2004's with 10" 250 watt subs and the Def-Tech Pf1500.

Reading asking questions and especially listening to the newer subwoofers that are out there such as the Paradigm seismic 12, the SVS cylinder subs and of course the Outlaw LFM series I feel it is time for a change. I want to eliminate the Def-Tech 1500 and replace it with an Outlaw. I also want to eliminate the use of the subs in the 2004's.
I was thinking of two combos and wanted some advice.
1. Two LFM-2's
2. 1 LFM-2 and one LFM-1/putting the LFM-1 in the rear of the room.

Does anyone have any suggestions?

Thanks, Frank
ps. If you look at my HT room from the site below my Pf1500 is to the right rear of the room. These pictures are not up to date as I have added six newer theater chairs.

Hi,

Either choice will provide plenty of dB's of quality bass and will be more than enough to fill the space you described (1787.5 cu. ft.). Going with two subs should pretty much guarantee you the ability for nice, smooth bass response throughout the listening area with appropriate placement.

The main benefit of the LFM-1/LFM-2 combo would be a bit more extension and headroom. I am not familiar with the Def. Techs so I can't offer you any personal experience there, but the PF-1500 has pretty deep extension, no? 14Hz or so if I'm looking at the correct brochure online?

I am definitely in the "you can't have too much quality bass" so If it were me (and I had a generous budget), I would be looking at an LFM-1/LFM-1 Plus combo with an SMS-1.

Based on the options you've laid out, my choice would be LFM-1/LFM-2, all the way.

Nice HT setup, by the way!

Most speaker manufacturers us the 3dB down point as the end of a useful frequency range, unless otherwise stated. Also, sub maximum output may include corner loading, or give output for both corner and non-corner placement.

A quick bit of poking around on the 'net and people seem to think that DT exaggerates by using a 10dB down point as the low frequency point on subwoofers. If true, then it's apples-to-oranges when comparing low frequency extensions to other manufacturers.

Excellent point! bb4tb is right.

A bit more searching on AVSforum yielded a user who claims to get 'pretty flat' response out of the 1500 down to about 20Hz using a BFD parametric equalizer but there are no professional reviews to be found and no reliable reports of frequency response at measured levels.

Based on the comments of users on the net surrounding the PF-1500 and the subs in the 2004's, I am confident that either pair of LFM's will easily outperform what you have in place now.

Tony.

Thanks To the both of you. The Pf1500 is a very powerful subwoofer that I was pretty impress by some years ago. The indicators that I have read were around 20Hz. This I thought was adequate.

I am going to do some measurements for the LFM-1. I know it can fit in the space where I have the Pf1500 however I do not know if I want that big of a piece of real estate taken up for this sub.

What about hooking up these subs? I have the Outlaw 990/7700.
Can either one of you guys give me a simple starter course without the meters. Can I still attain reasonable results?

Thanks Palmer for the compliment.

Hi again Frank,

You're welcome. I am envious of your setup since my HT is in our living room, which requires all sorts of interesting compromises.

Clean, powerful output at 20Hz is more than adequate for all but the most challenging material, in my opinion...

Matching sub output to your speakers without a meter will range from extremely challenging to impossible. You could use the 990 auto setup if you don't want to mess with an SPL meter. If you change your mind and decide to do it manually with an SPL meter, be sure to check out this thread on AVSforum. The Radio shack meter rolls off at very low frequencies.

http://www.avsforum.com/avs-vb/showthread.php?t=505236

Since you have two sub outs on the 990 you would not need a 'Y' adapter.

Cheers,
Tony.

The most basic setup you and a helper might try without a meter is to use some software to generate a sine wave tone at the sub(s)/mains crossover frequency and feed that into your system, likely in one of the stereo modes. The idea is that, if all is in perfect balance between your sub(s) and your mains, both the mains and the sub(s) will be contributing an equal amount of output at the crossover frequency. With one person being the listener and the other person being the switchover tech, alternate listening to the crossover frequency tone from the mains without the sub(s), then the sub(s) without the mains. Go back and forth with as little silence between sub(s)-listening and mains-listening as possible, adjusting the subwoofer level until the output of the sub(s) and mains seem to be practically the same at the crossover frequency for most of the prime listening area. If you experiment with sub placement, the level comparison will have to be repeated for each arrangement you try. I suggest two persons so that the listener does not have to lose the level impression they have between listening samples. Of course the two people can swap roles for a time to confirm your settings.

As further confirmation, listen to a recording that has one or more single, non-processed instruments with frequency components from those instruments that span both the sub(s) and the mains. In other words, you are not comparing the sound of a bass to the sound of violins, you paying attention only to instruments that have both low-bass and mid-bass/treble coming from the same instrument. Do those instruments sound natural and balanced regardless of what other instruments may be playing?

Definitely think about an SPL meter for the future.

Thanks Palmer and BB4theB.
Palmer thanks for the AVS web site. I am going to check it out. I am also going to think about the SPL meter.
It is not that I do not want to spend for the meter , (I know they are reasonable in price) it is the fact I do not understand the directions. It sounds complicated. Perhaps more than it really is in fact. Did anyone show you how to operate it? Maybe someone at the Shack can help.
My friend bought one and still has it sitting in his desk unable to figure out what the correct way was to operate it.
BB4theB you are really over my head. I appreciate all of your help with suggestions but with me it's the simple things I can handle.
Hey maybe you guys came come to Phila., set the subs up, listen to a few tunes and have a few beers!
All kidding aside I do appreciate all of the help.
Scott e-mailed me his suggestion of getting the LFM-2 and the LFM-1 Plus.
What do you guys think?

P.S. I am also in communitcation with the Mosses of this Audioholics forum Gonk, He agrees with both of you guys.
Thanks Frank

Check out the 990 manual - there's a pretty good walk-through on how to use an SPL meter to calibrate a system that can apply to the 990 or any other surround receiver or processor. Yo might point your friend in that direction if he has found the meter to be intimidating. It's not really a problem at all once you have some good instructions in hand.

If space and budget permit, the LFM-1 Plus and LFM-2 combo should certainly prevent any future "bass remorse" in your 1800 cubic foot space. You could run the Plus with the port plug in to get the bottom end, and the LFM-2 would help it cover the bass in the 30Hz and up territory with plenty of oomph while still letting it integrate nicely with the full range speakers. Connecting them wouldn't be hard: just connect each to one of the subwoofer outputs on the 990 (it has two sub outputs right next to the unbalanced center channel pre-amp output).

"Did anyone show you how to operate it?"

Absolutely. I learned everything I needed to know to do a basic calibration with an SPL meter on this forum and in my 1050 manual(it was less than half a page). Read through the walkthrough in the 990 manual as gonk suggested and post any specific questions you still have here. You'll get plenty of help, trust me.

Have confidence; you'll do just fine AND you'll enjoy your system even more.
Tony.