[Hipper]

I noticed when listening on good headphones certain subtle percussion on particular tracks which I cannot hear with my speaker set up and I ask if anyone has any suggestions as to what to do about it.

The percussion is from two tracks: Gene Clark and Carla Olson (album So Rebellious a Lover), Gypsy rider, the opening:

http://www.youtube.com/watch?v=w7JHROE5imw

It's not vital on this but it's a nice addition.

And Emmylou Harris (album Wrecking Ball) Every Grain of Sand, from 0.49 onwards for example:

http://www.youtube.com/watch?v=fa_XxS3GqAY

The percussion on this section is important as it adds a nice rhythm.

(of course you can't hear it on youtube!)

The frustration is if I put my ears right up to the tweeter I can hear these sounds but they melt away within a short distance. I can also hear them from my chair if I cup my ears (or put some sort of sound reflectors behind them). Moving my head side ways or up or down doesn't do the job. I did use the 'Tallboy' suggestion before but I don't think that solved it either.

I've had RM30ms for six years or so and currently have then set up in a 'Thirds' configuration, namely a third of the lengths out from the front and side walls and my ears a third out from the back wall. This gives a distance of around 163cm from the drivers to my ears.

I get generally a nice sound with a reasonably flat response as a result of room treatment and an equaliser.

I've tried adjusting the tweeter L-pads, and also adding to the treble on the EQ (from 8kHz upwards) but haven't found the right result which doesn't mess up vocals in particular.

Any suggestions gratefully received.

[John Casler]

What you are describing is basic "hearing and acoustics 101".

It is true with ALL speakers in ALL rooms.

You mentioned "cupping" and that "nearfield" listening are the only two ways to get what you want.

The reason the headphones do it is because they directly couple the drivers to the ear and eliminate the room (which is what nearfield and cupping do).

So move as nearfield as you can, and take a set of headphones and place them "behind" your ears to make your ears stick out a little more, and you may get a small increase toward your goal.

Additionally, make sure the "convergence" of the RM30s is "on axis" with your ears.

[Hipper]

Thanks John.

I have them toed in so they each point directly to their relevant ears.

It's so frustrating as the sound energy seems to be there if cupping etc. can pick it up.

[*Scotty*]

Cupping your ears changes their frequency response curve and may more closely resemble the frequency response curve of your headphones. Chances are good that neither your headphones nor loudspeakers actually have a flat response curve, so you hear what you hear and have to work around the warts. You might try tweaking your DEQ2496 to make   the missing information more audible through the loudspeakers.
  Scotty

[BobMajor]

Brian recommended toeing in the speakers so that they crossed about 20 inches in front of the listener (assuming only one person was in the sweet spot). Of course, the wave guides were trying to increase the sweet spot. But you could try this anyway.

[Hipper]

Thanks for all your replies.

As I understand it, for RM30s the crossover is at 6.9kHz. Therefore what I've done for the moment is opened up the L-pads fully for the tweeter (turned clockwise as far as they will go) and added 3dB on 8, 10, 12.5 and 16kHz using my equaliser (I don't allow any increase on the EQ of more then 6dB and have reduced every frequency by 9dB just to make sure I don't overdo things).

With this arrangement I can hear the Emmylou Harris percussion (very nice!). However, as always, there are penalties! It's resulted in some harsher female vocals at times, so I'll have to listen for a time and also see if I can control that.

What I would like to know is, is there any danger in using the L-pads fully open. As described above, the maximum effect of the EQ on any frequency is -3dB. I'm only 163cm away from the speakers and in a room 420cm x 386cm, and I don't like loud anyway.

[Hipper]

I think I've solved this problem without any penalties.

The cause seems to be in part my aging hearing. I saw this interesting comment by rbbert on this forum:

http://forums.stevehoffman.tv/threads/i-have-a-big-problem-my-stereo-is-too-good-too-accurate-i-cant-stand-it-sometimes.335418/page-9

To a certain extent, this actually is due to presbycusis, the loss of high frequency hearing that accompanies aging to one extent or another. Whatever your upper frequency limit of hearing is, sounds with frequencies around that, particularly sounds like cymbals that are likely to have energy both just below and just above the point where you really can't hear, can sound painful if they are above a certain loudness threshold. Now remember that it's not an all or nothing effect, neither the upper limit of your hearing nor the volume at which some sounds will become annoying, but it's a real phenomenon well described in audiology and psychoacoustics. I don't know how old people here are, but hearing loss is extremely variable. I'm 60, and I can hear a 16 kHz tone if it's boosted about 10-15 db compared to 1 kHz, but I can't hear a 20 kHz tone anymore even with a 60 db boost (and I'm unwilling to try more due to concerns about damaging equipment.)

Also remember that if you have some hearing loss due to acoustic trauma, that will put a "notch" in your hearing curve at about 8 kHz, which means that that distortion/unpleasantness that I mentioned above, that occurs around the frequencies where you don't hear well, may also be occurring with sounds in the 7 - 9 kHz range when they get above a certain loudness

I'm 60 years old and tested my hearing with test tones when I was 54 and it seemed then that I could just hear 10kHz but not 12.5Khz at normal listening levels, and that 12.5kHz also caused me ear pain. Recently I've found that 6.3 and 8kHz require 4dB added to level with frequencies below and if I add 16dB to 10kHz I can hear it but not at normal levels (I didn't want to go any higher). Even with a 16dB boost I cannot hear 12.5kHz.

The L-pad on the RM30Ms seems to have an overall adjustment of around 2dB.

It's strange that I can hear these frequencies better on headphones but of course the sound is at right angles to the ear compared with my speakers which are around 30 degrees.

What I did was level the frequency response with a microphone, software (REW) and my equaliser (Behringer DEQ2496). That of course does not reflect my hearing abilities so I used test tones (ordinary test tones, warble tones and pink noise - they are all heard slightly differently but do show similar trends) and listened. I ended up with 31.5 - 200Hz at 2dB higher then the middle frequencies, and 6-8kHz at 4 dB higher, lowering steeply from 10kHz upwards and smoothing the bits in between.

This has given me the percussion I wanted without the harshness.

[Hipper]

I woke up last night and had this idea (yes, I should have gone back to sleep).

It occurred to me that even if your hearing is gone above certain frequencies you can find out what you are missing by lowering the speed of the playback!

Obviously that's easier with vinyl but it can be done with digital too by using software such as Nero Wave editor, which has a 'Time Correction' tool.

Just a thought.