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Beaming/shouting

84.205.231.37
Posted on April 22, 2009 at 01:25:53
prots
 I set up my speakers in a new house room after about a year in storage.The room is about 4.5x6x2.3 metres so reasonable dimensions.The speakers are at least 1 or more meters from the back and about 70-80 cm from the side, 2.5 metres apart and I am about 2.5/2.8 meters from the speakers.The back and side walls are solid brick and one meter behind my listening position are double glazed sliding aluminum veranda doors.
I needed to bring the speakers quite a bit out (more than a meter)from the back walls to lessen the effect of soundstage smearing.
Associated equipment is 300b DIY integrated amp ,JEL/WALTON type,non-oversampling 1543 dddac.I am using the bastanis speaker cables and ic and magic filters.
HOWEVER, I still find I cannot get rid of a shouting/beaming/ringing sensation in the mid frquencies on certain voices,piano notes etc that I wrote about some time ago in my last house.I have switched out speakers to check and the effect is not there with the other speakers.
I remember the effect was there but less in the last house.I have tried moving the speakers around but the effect more or less remains.When I get up close to the speaker or even behind it the effect is there so I don't think it is the room set up.
Has anybody else noticed this?
Perhaps the speakers need another few hundred hours of running-in after not being used for a year?
Maybe the c37 etc treatment has dried up after many months in a highly oxidizing environment next to the sea where I used to be?

(By the way I want to COMPLAIN on the low quality of speaker basket painting--it started to peel and rust after 6 months in my last house-now you can imagine the hassle of trying to repaint and clean a speaker basket with the rest of the speaker parts attached.....)

Maybe I should line the basket with felt to minimize vibrations?

RE: Beaming/shouting, posted on April 23, 2009 at 23:46:55
Robert Bastani
Manufacturer

Posts: 224
Location: Germany
Joined: November 12, 2004
Contributor
  Since: October 7, 2004
 Hi,

the problem of rusty baskets is not common, the widebands are produced to common Eminence standards, you are the only one who reports this problem. There are other customers living at the sea, no problems with the baskets.
The cone- treatments reduce the usual shouting/beaming of a 12"- driver to a non-disturbing minimum and allow the driver to play free from a crossover and limitations in the frequency- band.
I remember you live in humid tropical climate and i can imagine that when the baskets rust also the paper- cones show issues caused by humidity, paper is much more sensible to humidity than painted driver- baskets. To check this out i can send you a pair of new widebands for a comparison, when the shouting is much better with the new drivers i`ll offer you a reduced exchange- rate. When you agree please inform me about your new adress via p.m.

Regards
Robert Bastani

P.s.

Beside the essential issues with the cones i recommend to realize placement and setup following this method:


Baffle- placement:

First connect the amp with the baffle- section (wideband and tweeter) with your speaker- cables like you are used to connect any other speaker.
Now you can find the right placement for the open baffles, just listen to solo a voice with fully paralleled speakers, as much space inbetween the baffles as possible and move them away from the backwall until the voices rise in height, voices should be centered in the middle between the speakers (if not check if the speakers are exactly paralleled, move one baffle only two centimeters back and forth and listen until the imaging becomes right).



Woofer setup:

1) Phase settings: The right phase is essential for natural sound although the changes are relatively subtle.
- Switch one woofer amp "off".
- Rise the croosover frequency for the woofer to max. and also rise the volume a bit
- Turn the phase knob listening to music until the basses are maximum fat and boomy at listening position.
- Reduce the level and crossover to normal.

2) Crossover settings:
- Switch the woofer- amps "off" and listen to the imaging of the baffles only (choose a choir or a big orchestra).
- Switch the woofer- amps "on" and compare the imaging, reduce or rise the crossover-knobs (of both woofer amps, both always the same frequency- settings) to the highest possible frequency which doesn`t affect the imaging of the baffles. My own method is to rise the crossover frequency in about 10 Hz steps from lowest position and compare the imaging of each step to the imaging of the baffles only.

3) Volume:
- The right dose of volume is individual and also depending on the room. In most cases the volume of the woofers is set too high in the beginning.

4) Remarks:
- The phase- and crossover- knobs of the two woofer amps always should be positioned identical.
- The volume may differ a bit because most rooms and speaker placements are not 100% symmetrical, this can follow volume differences in the bass range.
- The quality of records differs a lot and it is impossible to find the right volume for all your records with one volume setting. Choose a position which is fine for you with about 90% of your records and reduce or rise the crossover frequency a bit when you listen to a record which shows a different tonality. Probably you will end with three positions, the middle position is right for most records.

RE: Beaming/shouting, posted on April 29, 2009 at 04:28:43
protos
Audiophile

Posts: 19
Joined: October 8, 2007
 Well, after playing around with various placements to no avail I found out that the "ringing"/peaking on certain continuous notes is connected with the large patio double glazed sliding doors behind my listening position.When I open them (they can only open by sliding one behind the other so I cannot get 100% open space) the peaking reduces a lot.

I played some pink noise test tones and the problem is obvious around 500-1000hz only which is quite high for standing waves.Maybe its a comb filter effect but treating the back wall behind the speakers with some diffusers did not cure this unless it is a resonance of the glass itself which is excited directly from the widebands.Some simple curtain rollers in front of the sliding doors did not do much either so the next minimal invasion technique is to coat the glass doors with something like the 3m security film for windows .Maybe this will damp the resonance if that is what is happening.Otherwise will need expensive double curtains.

By using diffusers behind the speakers the soundstage is better though and as it is with the curtain rollers-less echo in the high frequencies I guess..Cheap diffuser trick is to get some polyester fiber panels used in building as heat isolation.They are more user friendly than fibreglass but of course you have to cover them with a fabric for something presentable.
Otherwise I found a very friendly company here in Greece (iselco.gr) that manufactures diffusor panels looking like wood or marble that are reasonable priced i.e.45 euro p.sq.m.Four 120X60x3cm panels would cost like 140 euro which is not bad compared to the hi-end offerings.

Funny thing with all this is that I still dont know why with the other speakers I did not get the same problem unless it has something to do with different room nodes excited by the dipole widebands.
So keep trying.....

Robert, regarding the rusting I of course did mention that I lived (not now) opposite the beach and the climate was understandably quite corrosive.However I was disappointed that the paint job hardly lasted 6 months.Perhaps Eminence do not sell comparatively a lot of open panel speakers that are more exposed to oxidization than closed baffle and so their quality level is geared to that end.I do not know how many Bastanis users are situated close to the ocean in a humid environment -probably not a lot.

Also ,do you recommend using something like the behringer equalizer to smooth out the bass frequencies only? It has an RTA so this helps and quite precise adjustments.
RE: Beaming/shouting, posted on April 30, 2009 at 01:53:52
Clive
Reviewer

Posts: 286
Joined: June 2, 2004
 I'll leave the expert replies to Robert but I've a couple of comments:

1) normal box speakers may not excite the same room issues due to dispersion characteristics and the way box speakers vs OBs energise the room with sound.

2) I used the Behringer for sometime with great success. The controls are not exactly intuitive though. I would add that the RTA may not be accurate enough at bass frequencies, even the manual states this - instead I used the XTZ room analyser. I have moved over the integrated the XTZ Sub Amp 1 DSP plus the room analyser. You can find a writeup of my experiences at www.enjoythemusic.com, the XTZ is much easier to use and in the end you get a better result.

RE: Beaming/shouting, posted on April 30, 2009 at 02:38:59
protos
Audiophile

Posts: 19
Joined: October 8, 2007
 It is hard to know whether my problem is a room node or a glass resonance.

Regarding the XTZ/Behringer , I have read your review but the behringer I think is much cheaper (350 usd vs 1000usd?)and does not need one to change the sysstem from active subs etc.You just connect it between the preamp and the subs as they are.

RE: Beaming/shouting, posted on April 30, 2009 at 02:49:06
Clive
Reviewer

Posts: 286
Joined: June 2, 2004
 Certainly the Behringer is much cheaper if you have the bass amps already or don't have any need to change them. If you use the RTA you'll need the Behringer or similar mic as well. The XTZ room analyzer is quite a bit more expensive than the Behringer mic but it gives you a better feel for what is happening in the bass.

The RTA in the XTZ or Behringer RTA may help you track down you patio door glass problem. I find being able to measure the room removes a lot of highly subjective guesswork. The freq seems high to be a room mode as such but I suppose it could be the res freq of the glass itself.

RE: Beaming/shouting, posted on April 30, 2009 at 03:07:46
protos
Audiophile

Posts: 19
Joined: October 8, 2007
 Actually I bought the XTZ room analyzer, mainly because of your review even though the behringer is an all in one solution (RTA/equalizer).I have not used the xtz yet it yet but it seems more detailed in the bass RTA so I was thinking of getting the behringer and combining the two for solving some of the bass problems.The behringer can adjust the bass frq quite well with the parametric eq as I see it, right?
Would this be a worthwhile upgrade for the bass?

RE: Beaming/shouting, posted on April 30, 2009 at 03:26:19
Clive
Reviewer

Posts: 286
Joined: June 2, 2004
 What you are planning to do is exactly what I used for several months very successfully. I used a combination of PEQ and GEQ, you should indeed get more accurate results with the PEQ but use what works for you. Assuming you have a room with room modes to tame (ie it's not HUGE)then it's a significant improvement to the bass performance of your room/system but the degree does of course depend on how your room measures in the first place.

Take some measurements first to find out how the room performs. In my room I used 3 position measurements to begin with but when doing the fine-tuning I used single position measurement, it's much faster and in my situation there was little difference between 1 and 3 position.

With the room analyzer and DEQ2496 it took me 2 to 3 hours to get a good result once I had opimized subwoofer placement - which ended up being exactly when I had them in the first place! With the XTZ Sub Amp 1 I got a flatter response due to the room analyzer programming the dsp for me but you will get a good setup with the DEQ2496 too.

RE: Beaming/shouting, posted on May 3, 2009 at 04:29:22
protos
Audiophile

Posts: 19
Joined: October 8, 2007
 Drat!
After further investigation I have come back full circle to the widebanders.Putting pink noise around 800hz and moving very close behind the widebanders the ringing is very pronounced so no way it is a room node or resonance somewhere else in the room.The effect is more pronounced behind the speakers than in the front.If you stand back a bit or even from the listening position this peaking or ringing has a "phasey " quality so you cannot really tell from where in the room it is coming from.
So perhaps Robert is right and the speaker has changed characteristics and the damping process has "worn out" and the speaker is resonating .
Robert, what are the problem frequencies that you cure with the damping process?

I guess I will have to get some new widebanders and keep my fingers crossed that that will be the end of it.

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