[RoadTripper]

I have two listening rooms. My living room which has my Panasonic XR45 plus VMPS RM40s has now become a home theater instead. All it took was the Panasonic AE700U digital projector plus the OPPO DVD player and I was in business. However, my wife wishes it was running surround sound with all the sis-boom-bah that comes with it. By that I mean sub-woofers.

I don't really get why my VMPS RM40s aren't enough to banish the need for sub-woofers since on paper they go down as low as any reasonable sub-woofer I have read about i.e. 25 Hz.

So, I have a few questions: first, can I do without a sub? My thought is to add the Behringer EQ system so as to be able to crank the bass a tad. That should turn my RM40 bass into effectively a pair of quality sub-woofers.


My second question is about the surrounds: what principles are in play in chosing them? Sensitivity matching? Cheaper is better? They don't add much so don't bother? Any help would be appreciated. As for placement, must they be behind the listeners or is off to the side just as effective?

Similar questions for the center channel.

My third question is what amp to replace my Panny XR45 with since as a result of being modded, it no longer does the HT thing but is two channel only.

[John Casler]

I have two listening rooms. My living room which has my Panasonic XR45 plus VMPS RM40s has now become a home theater instead. All it took was the Panasonic AE700U digital projector plus the OPPO DVD player and I was in business. However, my wife wishes it was running surround sound with all the sis-boom-bah that comes with it. By that I mean sub-woofers.

I don't really get why my VMPS RM40s aren't enough to banish the need for sub-woofers since on paper they go down as low as any reasonable sub-woofer I have read about i.e. 25 Hz.

So, I have a few questions: first, can I do without a sub? My thought is to add the Behringer EQ system so as to be able to crank the bass a tad. That should turn my RM40 bass into effectively a pair of quality sub-woofers.

My second question is about the surrounds: what principles are in play in chosing them? Sensitivity matching? Cheaper is better? They don't add much so don't bother? Any help would be appreciated. As for placement, must they be behind the listeners or is off to the side just as effective?

 ...

Sounds like you have a great project, but a lot of "what to do's".

First off there may be two reasons your RM40s are bass shy at the listening area.

1) Not enough power to move the woofers

2) Placement that creates a dip in response at the listening area.

3) Placement that doesn't use any of the room gain.

There are several solutions and you can choose any one, or all of them to try.

1) More power to the RM40

2) Work on different placement that will not only reinforce the bass, but also change the dip in response to outside the listening area.

3) Bass trapping devices can help

4) Add a Sub that can be placed in an area that doesn't excite the same bass nodes at the listening area.

Keep in mind that a device like an equalizer can be helpful at "lowering" peaks, but generally not to helpful at raising dips, since playing a frequency louder does not solve the sonic energy negation.

Most of the time, moving a speaker closer to the wall will reinforce the bass response.  Even more so, moving it toward or into a corner will usually help more.

Also while more difficult to do in most listening rooms, moving the listening postition closer or farther away can also make a small to huge difference.

As far as surrounds, the ideal is "matching", but an additional pair of RM40s might not be feasible.

Second on the list is "tonally matched" drivers, which would mean more VMPS speakers.

And in a pinch you might find that many good quality speakers would give you a sound that will satisfy you.

Generally side surrounds are slightly above ear level, and slightly behind the listening area, but placement will depend on the speaker, its type, your listeining position and the room.

[JLM]

I played with a JVC digital receiver last year.  IMO the rated 100 wpc is way over rated, probably due to lack of capacitance.  Many HT receivers with the same ratings only put out maybe 20 wpc into all channels.  My 6 wpc Clari-T (battery powered Tripath digital amp) has much more bass output and better control across the entire frequency range than the JVC.

Nearly all the sound you "see" coming from the screen is from the center channel, so don't skimp there.  I run a 2.1 HT and do feel that I miss quite of bit of the center channel information (but HT is a low priority to me).  Rear channels is another matter.  Except for straffing airplanes, they add little.  I suppose timbre matching them to the front channels is more important to avoid a possible distraction of them not sounding the same than anything else.

My local VMPS dealer has a couple of different HT speaker options that are VMPS I believe, one was dipole.

[fabaudio]

Nearly all the sound you "see" coming from the screen is from the center channel, so don't skimp there.  I run a 2.1 HT and do feel that I miss qui ...

 I could never understand those who say that a center channel is not necessary. It is indispensable for speech intelligibility.

[carlos spud]

you cant skimp on the center and the surrounds IMHO the surrounds actually have more sound coming from them than most people give them credit for i know for a fact that when i am not running my surrounds i miss em alot,also i belive there is no substitute for a good powered sub those big explosions and planes, car crashes ETC need that really low end response and in my opinon that is best achieved by a powered sub due to the fact that the amp on the sub only has to power one woofer instead of huge towers
my 2 cents, Spud

[ctviggen]

I personally would not be without a sub, as subs add much more to the overall effect (plus, where does the LFE signal go in your system?  Can you send it to the R/L speakers?) of the movie.  I have three -- two VMPS Largers and an SVS.  In stereo, I run the Largers; these are also fed LFE, as is the SVS.  The in-room response of my RM40s (no subs) are about 74 dB at 20 Hz, although I'm not 100% sure of this measurement (taken by EFT, but I plan to retest one of these days).  But you want power to 100+ dB for the big booms.  

As for the center channel, I think this is a very important speaker.  For the rear l/r, I personally don't think these are that important.

[zybar]

Nearly all the sound you "see" coming from the screen is from the center channel, so don't skimp there.  I run a 2.1 HT and do feel that I miss qui ...

 I could never understand those who say that a center channel is not necessary. It is indispensable for speech intelligibility.

It depends on the system and setup.

In my front pj setup, in a dedicated room where I don't have some hulking box messing things up, there isn't a need for a center channel.  

I have had a center channel in previous system configurations in this room and it didn't provide any clear advantage to a properly setup L/R config.

NOBODY who has has watched a movie, game, etc... has felt that things were missing, hard to hear, etc... regardless of their seat.

I have two rows of seating (three recliners in the first row and a couch on an elevated patform for the second row).

Now if I had a different setup, a center channel might be absolutely necessary.

As always, opnions vary and your ears should be the final judge.

George