[john1970]

Does anyone here play the LFE through their RM40 loudspeakers?  If the speaker can go down to  25 Hz (-3bB) I was thinking of purchasing the RM40 instead of a pair of RM30s with an inexpensive HT sub.

Just looking for advice.  Thanks.  

[JoshK]

I have ran my RM40s for my main two channels in a HT without a sub for years.  I had a sub before, but unless you are looking for super humugous impact from the deepest LFE possible, you won't miss anything.

[Skynyrd]

John,

My RM40's don't go anywhere near 25 hertz! If you're looking for deep bass extension, you'll need a sub with these speakers.  I use two subs, crossed at about 120 hertz.  Occasionally, I've seen posts on this site where people claim they are getting low 20's out of their RM40's.  Can't say mine do that, or even close.

 
See Ekovalsky's measurement's of his VMPS RM-X's for an informative bass-performance tutorial/exposition.


Skynyrd

[John Casler]

Does anyone here play the LFE through their RM40 loudspeakers?  If the speaker can go down to  25 Hz (-3bB) I was thinking of purchasing the RM40 instead of a pair of RM30s with an inexpensive HT sub.

Just looking for advice.  Thanks.  

If I understand you correctly the answer is probably no.

If you mean that you will take the LFE out, to an amp, and then power the Bass drivers (via the appropriate binding post), then it is not a good idea, since the RM40 bass system is designed to high pass around 220-280ish which is well beyond the bass management capabilities of most pre-pros, which seldom go above 100Hz or 120Hz.

If you mean that you will run the front MAIN channels as LARGE, and channel the signal to the mains "full range" then it will work fine as long as your room will support the bass wavelengths, as the speakers are postitioned.

[john1970]

Skynyrd,

Thanks for the info.  Then I will probably get a pair of RM30s and a sub.  Is there a link to Ekovalsky's measurement of the RM/Xs?

Thanks.

I have read the conflicting reviews of the RM40s bass extension.  When I auditioned a pair of RM30Ms the bass was flat to 40 Hz and -8 dB at 31.5 Hz in a very large room (25Wx30Lx16H).  My listening room is much smaller (12Wx12Lx8H) and I'm guessing that I would get closer to the -3 dB at 32 Hz which is claimed.   Lastly, the RM30Ms that I listened to were used a surround speakers and it is very possible that the PRs had not been adjusted.

[warnerwh]

I run a sub with my RM 40's. I run the 40's full range and there's no way to tell the sub is on. It's crossed at 40-45hz and integrates perfectly. You will have no trouble. With the RM 30's I"d run them full range and cross at 55hz which is quite low but perfect for what you need.

[john1970]

John,

My Marantz HT receiver has a feature where it will output LFE effects through the main speakers when the speakers are set to LARGE.   This is the feature I would use.

Thanks,
John

[John Casler]

John,

My Marantz HT receiver has a feature where it will output LFE effects through the main speakers when the speakers are set to LARGE.   This is the feature I would use.

Thanks,
John

That feature "folds" the low bass into the Mains and runs them full range, and would do what you want.

So yes that will work.  Do be aware however that the RM40's "LOVE" lots of power.  If you feed them well, they will behave quite nicely, and serve you well.

[zybar]

Does anyone here play the LFE through their RM40 loudspeakers?  If the speaker can go down to  25 Hz (-3bB) I was thinking of purchasing the RM40 instead of a pair of RM30s with an inexpensive HT sub.

Just looking for advice.  Thanks.  

John,

I felt that I needed a pair of Larger subs to augment the RM 40's when I owned them.

I used them in HT and 2 channel duty.

George

[john1970]

John,

Can you please quantitate LOTS of power?  I have a NAD C372 amp (2 x 170 watts @ 4 ohms continuous and 2 x 305 W @ 4 ohms dynamic).  Is this enough power?

Thank you again for the advice,

John

[John Casler]

John,

Can you please quantitate LOTS of power?  I have a NAD C372 amp (2 x 170 watts @ 4 ohms continuous and 2 x 305 W @ 4 ohms dynamic).  Is this enough power?

Thank you again for the advice,

John

In a 12 x 12 room that should work, but if you go up you might need more juice.  Make sure and plug the amp directly into the wall.

[James Romeyn]

The 40s woofers go up to 260 Hz & are crossed with only a first order network, so they extend up higher than that.  If you have a HT rcvr or pre-pro, you absolutely must set it up for SUB OFF, so the LFE go to the mains.  There are only reasons NOT to power the 40s bass with a LFE output, because its mono & you will have no program material above about 150 Hz max.

Not too long after the 30s arrived there were many posts on this subject.  Do a search & read them.

I've owned both systems, & have heard them in several or more venues, rooms, & systems.  I consider myself very familiar with them.

I far prefer the RM30/sub combo to the RM40's, especially visually.  The image/stage performance of the 30s linesource is better vs. the 40s symmetrical array.  It's subtle yet noteworthy.  To me, a 30/sub system is a junior $13k RMX, & even appears to have an interesting advantage over the X (the ability to cross around room modes in the bass range).

The VMPS Smaller Sub may have similar or lower bass cutoff vs. the 40s.  Plus the 30s dual 6.5" midbass & low midrange beats the 40s dual 10s (the cone/ribbon mid crossover point is about middle C).      

The icing is that the 30/sub combo costs less.  The only potential problem is a bigger footprint, but there are wide siting options for the sub, because you can cross it below 50 Hz.  

BTW, if all your sources go through the DAC within a HT receiver or pre-pro, I highly recommend you try high-pass crossing the 30s.  This will minimize distortion & power requirements, & increase mid-bass quality & the dynamic envelope.  Also, depending on the sub's performance at elevated frequencies, high-pass crossing the mains may allow you to flatten one of your room's bass modes at elevated frequencies (manipulate the sub & main crossovers).  

The engineer who designed my room modifications said speaker siting recommendations for a particular room shape are available for free on the net.  I'd check into those because his recommendations caused huge improvements.  

Lastly, you absolutely positively must get the Constant Directivity Waveguides.

If space permits, I'd try siting the sub at one of the front corners.  Test for room modes at that location, but with the sub crossed low, like about 35-40 Hz if you run the 30C's with no high-pass crossover.  If only one mode appears, it can be tuned out with the parametric eq.  The boundary multiplication will be immense, further minimzing THD & power requirements.  Distortion caused by boundaries as secondary sources is minimized, because direct output is virtually nill (good with bass, bad at higher frequencies).  This is another advantage for a sub/sat system, & a disadvantage for fullrange.

I've read all the arguments justifying the claim that one sub is to be avoided.  In use it appears to be purely theoretical.  Stereo subs may be better, but I've heard some of the best stereo fullrange sytems, & one sub works great when it's the right sub & setup right.  It takes time to setup, but it's worth it.

[john1970]

Jim,

Thank you for your detailed advice.   I was looking for someone to give a detailed comparison of the RM30s and RM40s.  

John

[ctviggen]

Personally, I've never been able to figure out where to put a single sub so that I couldn't localize the sub.  However, I've not had purely rectangular rooms with "infinite" placement capabilities.  The room I'm in now, for instance, has only a few options to put a single sub.  In each of those options, I can localize the sub.  Thus, I went to stereo subs (though have never dialed them in because of amp problems; when you only have one channel working, it's hard to dial in two amps).  I'm currently not using the RM40s with the subs.  

I also wouldn't put the LFE to the RM40s.  I have a large room and I have three subs (two of which aren't working).  My SVS sub is overwhelmed by the size of the room.  Maybe I'll run the speakers this weekend without a sub and see what happens.

[Jack D.]

What the heck is LFE?

Low Frequency Explosions?

[woodsyi]

What the heck is LFE?

Low Frequency Explosions?

Yes, among other thing.  E stands for effects.

[Jack D.]

Thank you woodsyi,

Can you tell, I'm a music/stereo type guy?

[ted_b]

I own RM/X's and a RM30C for center.  My music surrounds are 626r's, and my movie srrounds are two pairs of Alon dipoles  I have dual subs.  Even with the prodigous bass handling of the RM/X's I still run to subs for LFE (and some BM from the hirez stuff), and would not recommend doing otherwise.  LFE (low frequency effects) is a distinct channel that is often sloppily configured, and may contain even 120hz signals.  To send a channel that may have phase issues and is certainly full of 10-25 hz content, to another speaker if you don't have to is asking for trouble.  Best case, you muck up the music signal that the RM40's are looking for; worst case, you ask the speakers to do way more than they should.  

My $.02.  YMMV

[Skynyrd]

John,

The RM40's are a three way--both of the ten inch woofers get the same signal from the crossover.  That's how mine came wired.

The RM30's are a four way--but I don't own them and haven't actually looked inside to be sure.  

I think it is easy to think that the RM40 is a four way, and mine certainly are not.

I tried finding the "Ekovolsky" links for you regarding his measurements on the RM-X's--I couldn't find the exact links.  Do a sort by "ekovalsky" when you've got time!  

Back to the bathroom remodel, no $ for CDWG--I need a tub, sink, toilet, tile, etc. etc..
Skynyrd

[warnerwh]

Skynard: I believe the low bass woofer rolls off naturally on it's own around 80hz without any crossover components. So in effect it is a four way design. Brian will have to confirm this of course as I'm not positive.