Acoustic treatment and DSP - some questions

[DuckToller]

Hi everyone,

after having invested in heavily appreciated "fanboy" gear like REGEN USB , CURIOUS CABLE and a KLEIN DAC (See more here) in my first year with the CA community, I have had a read here on the "biggest bangs for buck" threat, which convinced me, that doing something on the acoustic treatment of my listening room

should be the next step before investing even more on hi-end equipment. Maybe investment on useful hardware like the minidsp UMIC or an antimode processor still does make sense, even a bass enhancement with a good sub could be adjusted to the plan.

 

I have two B&W 805s in a "golden" triangle position with my armchair and with the speaker positioning I am quite happy so far (in detail dist. to sw 61cm dist. to rw 131cm, dist. to other Speaker 181cm, dist. to listening position 181cm (157cm from the straight line between the speaker). What needs to be improved - in my opinion- , is a noticeable hiss from the left with sharp high tones , i.e. the harp sound in "Postcard Blues" /Cowboy Junkies/Trinity Session or some of Jan Garbareks sax notes are sounding kind of unwelcome.

Plus, even I had looked for a n symmetric and equilibrate approach to the room, I sometimes get the impression that the left speaker is more present than the right, could that be related to the different surface of the sidewalls ? And yes, having exchanged the speakers from left to right gives me the same phenomena. ;-)

 

In addition my speaker have some limits in presenting the deep lows as their frequency response is 49Hz - 22kHz at +/- 3dB and the frequency range should be -6db at 42Hz and 50kHz.

 

For starting this project on acoustic treatment , I'd like to ask:

- Is it inevitable to commence with a measurement of the room nodes or are some first steps to improve rather obvious for some expert eyes?

- Which would be the software of choice for the measurement ?

- Does a Android app like "Audio Tool" on a Sony Z1 could do the job, first hand?

 

My first ideas had been about having some canvas or molleton curtains for the last 150cm on the sidewalls, and maybe some absorber hanging from the ceiling, allowing me to reshape parts the ceiling in a more symmetric way,

but only on the right side (WAF), as I would not like to cut too much the luminosity in the room. That said, would a linen drapery on the glass front of the window have some effect as well beside it translucent looks ?

- Is there anything I could improve on the first reflection points ?

 

I welcome your thoughts and inspiration on the subject

Merci Tom

[wgscott]

1. What's on the floor?

 

2. Dirac Live trial or AudioTools should be fine.

[DuckToller]

Tiles (natural stones) and several carpets, one 150x80 between the speakers, one 2x1m before/under armchair, one 2x1 covering the winecellar door, and another small carpet in front of the desk.

[DuckToller]

AudioTools for Android? The windows software with that name seems to be an audio converdion tool.

[DuckToller]

And from dog avatar to dog avatar:

Thank you for your quick response ;-)

[wgscott]

I'm sorry. There is an iOS app called AudioTools which is what I thought you were talking about.

 

In any case, for just getting an idea of what is going on, there are a lot of inexpensive options, some

even are free like Room Equalization Wizard (which I find too complex), or a free trial like Dirac.

 

Would a toller get along with a small golden?

[DuckToller]

Thank you for clarification, and, Tollers usually get along with any kind of Retriever, just the species of Jack Russell or Pinscher are kind of arch enemies (IMHO, most of the times from the heat comes the terrier side)

[Guidof]

Personally, I found that an isosceles (rather than equilateral) triangle yields a more three-dimensional and more accurate soundstage. I would try that (it's free ;-)) before I'd try anything else. I would also try to position the speakers at equal distance from the side walls, if possible.

 

Best luck!

 

Regards,

 

Guido F.

[DuckToller]

I would also try to position the speakers at equal distance from the side walls, if possible.

 

Hello Guidof,

merci for your suggestions.

I have pushed around my speakers several times around before finding this position which offers a very good soundstage in depth and width. And, maybe contrary to the visuals, the speakers are equally distanced to all walls.

Main problems are the hiss, some small inquilibrity and the missing PUNCH with music that demands that due to speaker choice.

kind regards Tom

[Guidof]

Hello Guidof,

merci for your suggestions.

I have pushed around my speakers several times around before finding this position which offers a very good soundstage in depth and width. And, maybe contrary to the visuals, the speakers are equally distanced to all walls.

Main problems are the hiss, some small inquilibrity and the missing PUNCH with music that demands that due to speaker choice.

kind regards Tom

 

OK, I see. About the hiss, could you describe it in a bit more detail? Is it really hiss, as in the old 'tape hiss', or more of a shrillness in the treble? If truly hiss, it would seem unlikely to be a speaker problem, more likely an issue with the electronics. Is the hiss always in one speaker, or does it move to the other speaker if you reverse the speakers leads?

 

Absorption at the first reflection points is always helpful in cleaning up the sound, but I would doubt that I would cure the hiss. You mention room modes, but these are generally in reference to low frequency 'boom'. This would not seem to be a problem for you.

 

Before spending any money in room treatment, you may want to try placing some temporary heavy blankets at the first reflection points.

 

Measurements can be helpful in diagnosing where the problem lies, but probably are only useful as a starting point. I say this because we each favor our own particular kind of sound, and that is unlikely to be reflected in measurements, e.g., your mention of lack of PUNCH. Maybe achieving the punch you like would require a non-flat room response. In this regard, you may want to have a look at the late J. Gordon Holt's article "Down with Flat" (in the Stereophile web site).

[livelistenlearn]

- Which would be the software of choice for the measurement ?

- Does a Android app like "Audio Tool" on a Sony Z1 could do the job, first hand?

 

have played with android apps like 'RTA pro analyser' + 'speedy spectrum analyser' on a GS5 using the onboard mic… generally, gives one a general idea/picture of what’s going on.

now using umik1 mic > ‘signalscope’ app on iPad air:

http://www.computeraudiophile.com/f23-dsp-room-correction-and-multi-channel-audio/ipad-ext-mic-%3D-rta-25924/

In addition my speaker have some limits in presenting the deep lows as their frequency response is 49Hz - 22kHz at +/- 3dB and the frequency range should be -6db at 42Hz and 50kHz.

 

consider active subs to complement your 805s. that can take you down to at least 30-ish = RELs/JBLs/Velodynes. btw, 2 mid-size subs may sound better than one behemoth.

 

Plus, even I had looked for an symmetric and equilibrate approach to the room, I sometimes get the impression that the left speaker is more present than the right, could that be related to the different surface of the sidewalls ? And yes, having exchanged the speakers from left to right gives me the same phenomena. ;-)

 

'dirac live'. it is good.

1. measures system output (with/without subs)

2. optimises system output to target curves (tweak-able).

3. auto-addresses L + R speaker volume + delay.

 

hth

[DuckToller]

OK, I see. About the hiss, could you describe it in a bit more detail? Is it really hiss, as in the old 'tape hiss', or more of a shrillness in the treble? If truly hiss, it would seem unlikely to be a speaker problem, more likely an issue with the electronics. Is the hiss always in one speaker, or does it move to the other speaker if you reverse the speakers leads?

 

...

 

Before spending any money in room treatment, you may want to try placing some temporary heavy blankets at the first reflection points.

 

 

...

 

In this regard, you may want to have a look at the late J. Gordon Holt's article "Down with Flat" (in the Stereophile web site).

 

Hello Guidof,

thanx a lot for your thoughtful response. First point, I need to excuse the lack of precision when using English (only my 2nd language, which I usually like for being used comfortably in a more unprecise manner compared to German, my mother tongue, where I have the tendences to be over detailed, ...)

 

Secondly, there seems to be no problem in the electronic chain, over my HD650 in the NAD Pre I am having a good and balanced sound, compared to the BWs in a way darker tone.

 

And it is a shrillnes in the trebles which I was describing in my first post, which imho are - without treatment - a bit too present and with tones which are critical sometimes tending to be nerving. And these tendencies are audible in that speaker where these instruments are just playing the high tones, so it is a kind of speaker changing effect

 

I did your trick with the blankets! Absorbing effect immediate, the sound not any more so bright as it used to, but the whole soundscape directly more focussed and: No Shrillness. Plus it provoked a bit dryer bass sound, not the "punch" but in the right direction. With that some booming was audible as well, so there might be a need for correction if more bass is inserted in form of an active sub ...

 

Nonetheles thank you for your advice, I feel a bit more confident now to do the right things.

 

A bientot Tom

[DuckToller]

 

consider active subs to complement your 805s. that can take you down to at least 30-ish = RELs/JBLs/Velodynes. btw, 2 mid-size subs may sound better than one behemoth.

...

'dirac live'. it is good.

1. measures system output (with/without subs)

2. optimises system output to target curves (tweak-able).

3. auto-addresses L + R speaker volume + delay.

 

hth

lll or is it LLL ?

Thank you for your response.

Some more question:

- 30-ish in cm or Hz ?

- If cm of Sub-chassis, mid size would be 8' subs ?

- Does DIRAC live support 2.1 and 2.2 Channel audio? I have seen 192hz as a new feature, but only 2 channel audio.

- And do I guess correctly, the 2nd sub would get it's signal from the first that is connected to the RCA sub output of my NAD pre amp ?

 

I had already checked the xtz.se site, as they push a new and very affordable model , 10.17, to the markets this month. They will have some 8.17 staring of next month. But with their size they do not arrive sub 30 hz. I am not sure that would help too much.

 

I am just a bit confused where else to look for companions with my 805s as I usually get a response way above my budget as soon any vendor hears/read Bowers & Wilkins 805. SVSound for example advises only their top model to pair with the 805s, unfortunately space and money are not endless here, and for a small room solution I am not yet convinced to need 1100w available .... and the WAF of a 1100w sub is ... coughing .. not exactly proven.

 

Cheers Tom

[Guidof]

@DuckToller

 

Glad you seem to be moving in the right direction!

 

If you add a sub, especially in a smallish room (like mine), you may want to consider active room correction. Tube traps work, but are expensive, cumbersome, and have zero WAF. I use a DSPeaker Dual core (see sig), which has the advantage of providing parametric EQ in addition to room mode control. It works beautifully, but it's not inexpensive.

[DuckToller]

@DuckToller

 

Glad you seem to be moving in the right direction!

 

If you add a sub, especially in a smallish room (like mine), you may want to consider active room correction. Tube traps work, but are expensive, cumbersome, and have zero WAF. I use a DSPeaker Dual core (see sig), which has the advantage of providing parametric EQ in addition to room mode control. It works beautifully, but it's not inexpensive.

 

@Guidof

Yes I've noticed that.

Me too, has taken into account the DSpeaker Anti-mode 8033 SII as an option.

Could you elaborate why you have decided for the Dual Core in your case?

Did you test a software solution like DIRAC LIVE before choosing an active hardware?

Merci Tom

[livelistenlearn]

lll or is it LLL ?

 

lll is cool, thanks

 

- 30-ish in cm or Hz?

30-ish Hz. yes, 8” cone should be fine.

 

I am just a bit confused where else to look for companions with my 805s as I usually get a response way above my budget as soon any vendor hears/read Bowers & Wilkins 805... and the WAF of a 1100w sub is ... coughing .. not exactly proven.

waf-wise + for a cosy listening room, try auditioning a pair of these:

 

Home & Home Theatre Subwoofer. T-5 World Wide | REL Acoustics

Home & Home Theatre Subwoofer. T-7 World Wide | REL Acoustics

- Does DIRAC live support 2.1 and 2.2 Channel audio? I have seen 192hz as a new feature, but only 2 channel audio.

- And do I guess correctly, the 2nd sub would get it's signal from the first that is connected to the RCA sub output of my NAD pre amp?

unlike yamaha’s ypao or pioneer’s mcacc calibration systems for home theatre (ht) amps, dirac stereo does not auto-detect the number of speakers (cannot comment on dirac full because not using this flavour).

so, yes, there is no 2.1 or 2.2 option to specify in dirac stereo. mentioned ‘with/without subs’ because one might want to measure in-room responses, pre- + post-subbing.

btw, (many) active/powered subs now come with two inputs =

(a) LFE (low frequency effect) inputs can be plugged directly into ht and/or hi-fi amps with dedicated sub outputs. on-board e-crossovers will then auto-calibrate and auto-set sub levels… that may still be adjusted on the amps.

(b) most subs also offer low-level inputs for direct connection to speaker output terminals. if one's amp comes with two sets of speaker outputs, 805s can be plugged into speaker A outputs while active sub(s) may be wired to speaker B output(s). volume control + active crossover knobs on the subs allows one to manually set sub levels as desired.

iinw, as far as dirac stereo is concerned, a 2.1 or 2.2 system will be ‘calibrated’ and ‘corrected’ as a ‘stereo' system.

[Guidof]

@Guidof

Yes I've noticed that.

Me too, has taken into account the DSpeaker Anti-mode 8033 SII as an option.

Could you elaborate why you have decided for the Dual Core in your case?

Did you test a software solution like DIRAC LIVE before choosing an active hardware?

Merci Tom

 

Hello Tom:

 

I used to have an Anti-Mode 8033, indeed, I still have it somewhere in my closet. But the 8033 only controls the sub. Because I run my main speakers full range, I needed to control both the main speakers and the sub at the same time (i. e., a 2.1 arrangement). Hence the Dual Core, which does both. I might add that when we moved from our large Maryland house to our current, much smaller California residence, I could not have successfully integrated my Martin Logan SL3s into the 9'-6" x 14'-6" room where my listening takes place without the benefit of the Dual Core.

 

But No, I never tested DIRAC.

 

Best,

 

Guido F.

[DuckToller]

@guidof

 

Thank you for this explanation. Unused gear seems to be often stored at the silent place (German wording for WC), I did not read that the first time on CA.

I need also to excuse for my absence. Some important family time was needed in the light of the Paris attack. My wife's workplace is there and she has to travel there 3-5 days a week by TGV.

TOM

[DuckToller]

Hello Ill,

Thank you for your explication and your recommendation. The REL are very nice, indeed.

 

But I have now made an decision for an pair of the brand-new XTZ 10.17. The ceo of that Swedish brand is also involved in the Dirac research project.

 

I will need to find out whether I will be forced to use an active cross-over option like minidsp 2x4 or the antimode 8033 to manage the bass force.

 

I'll try to finish my room treatment project until Xmas, with some basstraps and many first point reflection absorbers before diving into room correction, if necessary.

Cheers Tom

[Guidof]

@guidof

 

Thank you for this explanation. Unused gear seems to be often stored at the silent place (German wording for WC), I did not read that the first time on CA.

I need also to excuse for my absence. Some important family time was needed in the light of the Paris attack. My wife's workplace is there and she has to travel there 3-5 days a week by TGV.

TOM

 

Hello Tom:

 

In US parlance the closet is not the WC, but an armoire-like enclosure :-)

 

Cheers,

 

Guido F.

[DuckToller]

This one is on me, flush .. eh .. blushing! ;-)

Cheers

[livelistenlearn]

 

But I have now made an decision for an pair of the brand-new XTZ 10.17. The ceo of that Swedish brand is also involved in the Dirac research project.

 

I will need to find out whether I will be forced to use an active cross-over option like minidsp 2x4 or the antimode 8033 to manage the bass force.

 

firstly,

good to know/‘hear’ family + you are fine.

after getting the XTZs = 3 options:

1. the old school 'manual’:

controls on the rear panel of the XTZs = crossover point, phase, volume, low pass, ‘eq' settings.

with a suitable RTA, one may measure the combined output of 805s + XTZs… and use the ⤴︎ controls to tune as necessary.

2. adding-on 'minidsp or dspeaker antimode’:

guidof and other users of the minidsp/dspeaker products should be able to provide valuable advice.

3. going 'dirac’:

software on mac = pretty simple, just read a bit and follow instructions. for some helpful hints and comments:

http://www.computeraudiophile.com/f23-dsp-room-correction-and-multi-channel-audio/dirac-live-room-correction-suite-initial-impressions-free-trial-15137/index2.html

 

http://www.computeraudiophile.com/f23-dsp-room-correction-and-multi-channel-audio/dirac-and-el-capitan-os-x-10-11-a-26025/

 

 

choice is yours have fun...

p.s. if going for option 2, minidsp ‘reads' to have more flexibility but have not used/heard a system equipped with it. antimode, yes, and would say it does a decent job of controlling sub-bass.

[DuckToller]

III,

Thank you for your thoughts.

And for layin' out the options.

I'll start with 1, but have ordered the minidsp gear (2X4, UMIK) and will try REW first before doing the Dirac live trail.

We have just decided that our 12 year old will get the old equipment consisting of infinity 61 mk2 and HK Amp with a streaming device in his play/work room for Xmas, so minidsp will have some work to accomplish as it is less then 12 sqm.The floorstanders will be close to the wall and the corners, and the room is square...

A bientôt Tom