[jermmd]

A friend lent me a CD with test tones on it and I get a significant db drop when I go from 80 to 65 Hz and below.  Shouldn't the volume stay relatively close to lower frequencies then that?

How should I adjust the speakers to boost the low end?  Will adding/removing putty effect the volume or just the tone?  Is speaker positioning more important?  I can't really move the speaker to far back against the wall but I can move the speakers forward into the room or closer to/ further from the side walls.  Maybe I should lower the treble and midrange pots to compensate for the bass.  Or would this leave me with too much volume in the upper bass frequencies?

Any help would be appreciated.  I am going to play with the system tonight after the kids go to bed.

Joe M.

[Brian Cheney]

If you haven't adjusted the PR putty do it now.  We ship the system overdamped so that you only have to remove putty rather than add it.

In room bass measurements are subject to peaks and dips due to room resonance modes, with +/- 15dB swings not unusual.

[Tyson]

move them closer to a wall (as much as possible), lower the mid and high pots, and remove some putty.  The pots and the placement will have the most effect on low bass volume boost, the putty removal will let you tune them to get "tight" bass.

[Marbles]

If your using a Radio Shack SPL meter, make sure you use the correction chart.

[jermmd]

Also, the room has no treatments and there is a RPTV between the speakers.
I will try to add a photo of my system.  I seem to get stuck on the resizing Jpg screen when I upload photos.

Joe M.[/img]

[jermmd]

Wow, quick responses.  Thanks.
I am using the RS meter without adjustment.  I'll google the subject and make those adjustments.  The decreased lower bass is obvious to my ear regardless of the SPL meter.

Tonight I will move the speakers around and play with the putty.  My fear is that my room may be the problem.  My wife won't go for the bass traps right now.  How low should the RM30's go before you see significant loss of volume?

Joe M.

[Marbles]

Here is the chart:

10Hz add 20
12.5Hz add 16.5
16Hz add 11.5
20Hz add 7.5
25Hz add 5
31.5Hz add 3
40Hz add 2.5
50Hz add 1.5
63Hz add 1.5
80Hz add 1.5
100Hz add 2
125Hz add .5
160Hz add -.5
200Hz add -.5
250Hz add +.5
315Hz add -.5
400Hz add 0
500Hz add -.5
630Hz add 0
800Hz add 0
1kHz add 0
1.25kHz add 0
1.6kHz add -.5
2kHz add -1.5
2.5kHz add -1.5
3.15kHz add -1.5
4kHz add -2
5kHz add -2
6.3kHz add -2
8kHz add -2
10kHz add -1
12.5kHz add +.5
16kHz add 0
20kHz add +1

[ctviggen]

Joe,

With my RM40s, my room is the following (with corrections for RS meter):

20Hz   74.5
25Hz   78
31.5Hz 72
40Hz    73.5
50Hz    78.5
63Hz    71.5
80Hz    74.5
100Hz  83
125Hz  77.5
160Hz  79.5
200Hz  80.5
1kHz    82

I took these measurements immediately after receiving my RM40s, before any putty changes and before moving them into their current positions.  I haven't taken any additional measurements.  This is without sub, so I'm surprised the RM40s are going that low.  I think the positions they are in now have reduced bass response but better imaging (they're farther from the rear wall but also farther from the side walls and the first reflection point is behind the listener).  Perhaps we can get together again, and I'll move your speakers around while you listen/take measurements.  I know from moving the RM40s (which are surprisingly easy to move on tile) that it's a pain to move the speakers, go sit down and listen, get up and move them again, etc.

[jermmd]

Bob,

Those numbers are amazing.  I don't doubt it after hearing your system; amazing speakers.  I will definitely take you up on the offer.  Let me know when you want to come over.  I need another set of ears to reinforce the changes I make anyway.

Joe M.

[jermmd]

Marbles,

Thanks for the chart.  I've printed it and put it in the case with the meter.

Joe M.

[Tyson]

Also, try swapping the speakers so that the bottom woofer on the side is facing out instead of in (or in instead of out).  Sometimes the orientation of a side firing woofer will have a big effect on the bass output.

[ctviggen]

Hi Joe,

It would be good to get together again, as I could do the moving while you're sitting and listening.  I also would like to see what happens if you reverse the directions of the woofers.  Perhaps we could arrange the speakers to get the best output with the woofers pointed one way then arrange them with the woofers pointed the other way and just see what the difference is.  This weekend, my mother is here from PA, but the next few weekends are relatively free.

[jermmd]

Well, I spent hours moving the speakers forward, backward, and side to side.  I played with the pots.  I still get a major drop off below 80Hz.  I haven't played with the putty and I haven't tried reversing the speakers so the side firing woofers face in (good idea!).

Are other RM30 owners getting decent low bass with their rooms/setups?

I am also going to switch out amps and see if that helps.  I have my speakers biamped with a 200W/channel Sherbourn now and I have a 200W/channel EAD powermaster 1000 I'm going to try.

I thought I should mention that I have the Auricap upgrade and the Megawoofer upgrade with my speakers.

Just so people don't get the wrong idea, I LOVE these speakers. Imaging, soundstage, detail, and everything but the lowest bass is magnificent.  I just want to make sure I get everything they're capable of.

[Marbles]

The amps aren't plugged into anything but the wall are they?  No power conditioners, no power strips?

[jermmd]

Amp is plugged into a bpt 3.5 power conditioner.  Isn't that good?

Joe M.

[JoshK]

Amp is plugged into a bpt 3.5 power conditioner.  Isn't that good?

Joe M.

You should be fine there.  How long have you had your RM30's?  Take a rough pea size amount of putty off each side and you'll be surprised by the change in bass response.

[zybar]

Joe,

It is a speaker placement issue and not the speakers or the amps.

Remember from my last visit that we talked about needing to do optimal placement AFTER break-in.

I will try very hard to come over in the next few weeks to assist.

Just got back from UK and it is off to Denver tomorrow.

George

[Marbles]

Amp is plugged into a bpt 3.5 power conditioner.  Isn't that good?

Joe M.

Joe, that's about the ONLY power conditioner that I wouldn't worry about.
Most all others will constrain the bass response of the amps.

[jermmd]

Joe,

It is a speaker placement issue and not the speakers or the amps.

Remember from my last visit that we talked about needing to do optimal placement AFTER break-in.

I will try very hard to come over in the next few weeks to assist.

Just got back from UK and it is off to Denver tomorrow.

George

George,

I have moved these speakers all over the place and although placement did change bass response, I never got significant bass below 80 Hz.  I'm confident it isn't an amp issue, but I do have concerns about the speakers ability to do low bass.  I expect deeper, louder bass, especially using the megawoofers.

Joe M.

[warnerwh]

You should go to realtraps.com or rivesaudio.  A typical room can easily go + or - 15 db. I have been able to attain close that in my dedicated room.  I had a severe peak around 63hz and a dip at about 50 (+12db and -14db and had to make more bass traps.  The putty can make alot of difference but it's better to have bass traps also. Learn about room acoustics and treatment.  I could very well be that bass traps would strengthen your bass response.  Anybody who's serious and can get away with it where there system is has these. At the Rives site there's some software that you just enter in your room dimensions. It will tell you where your room modes are. Or you can call realtraps or rives and they'll tell you where your room modes are. They have to be there as all rooms have them it just depends on your dimensions.  The big problem area in almost all rooms is below 200hz.  A side benefit to room treatment is your system will sound better than it ever has by quite a margin most likely.