# Acoustics tips and help, please



## atledreier

I've been hijacking so many threads in this forum I think it's time to start my own.

My room:
390cm wide by 530cm long, 230cm ceiling.
Floor is concrete (basement) with laminate wood on top. Walls are panelled wood(sp?) for the sides and ceiling. Front wall is plaster with wallpaper, and rear wall is plaster/wallpaper, but with a big glass door to my office.
Some carpeting on the floor, and three bookshelves with books and DVDs. A dysfuntional fireplace and a bit of clutter as well. 
A three seat sofa is pretty much all the furnishing in the little room.

There is a 3' opening to a hallway and stairwell in the right wall, just rear of the 1st reflection point. That is covered with a light drape.

My system is off center in the room, after advice I got here, and it works really well. Smoothed out the response and kept imaging, so I'm happy with it. That also made access to the back of the room better. 
I have my subwoofer located behind my listening position.

I have in total 5 sheets of 1,5" rockwool acoustics panels, and 3 sheets of 4" Rockwool.
I have treated the sidewall 1st reflection of both fronts with 1,5" panel, and also the reflection off the front wall with 1,5" panels. The 4" panels and a 1,5" panel are straddling corners as basstraps.


I have more acoustic panels on the way, and will make proper floor to ceiling bass traps in every corner of the room.
I have some nasty dips in my response, and I wouldl liek to have them smoothed out. I have had my current setup for about two months now, and I think my house curve might need some adjusting, there's just too much low-end level now. I have a +10dB hard knee curve. It's very cool to have my sofa shake and jump around for action movies, but sometimes it just gets too much. I think I'll try to go with +3dB and live with that for a while and go from there. Or it could be that it's just a little bloated from too long decay or something. I don't really know. I've also though about maybe making some diffusors. I don't wan the room too dead, but I'm an imaging nut, so I want crisp and sharp without being harsh. I know my components can do that, so it's all in the room.

Anyways, maybe some tips to what I can do better? I can post any measurement you like, including REW and trueRTA, so just let me know what you need to assess my mess.. 

A picture says a thousand words, so here comes a few thousand words worth of pictures of the room. I had no thought for proper photography when I took these, so bear with me.. 
































































My current sweetspot response in green here:


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## Ethan Winer

atledreier said:


> maybe some tips to what I can do better?


Nice sub, that's the same one I have. Mine is in a corner though, and it absolutely rocks there!

The biggest problem I see is the reflecting doors not far behind your head. You really need absorption there - the thicker the better. Maybe panels on stands?

--Ethan


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## atledreier

You should feel it in a nearfield position like I have it... :hsd:

I am not too fuzzed about aestethics.. Maybe I could hang some panels on the doors themselves?

Even though I use it for HT, the main concern is overdampening the room. I listen most critically to music. Maybe some diffusion somewhere?


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## Ethan Winer

atledreier said:


> You should feel it in a nearfield position like I have it... :hsd:


Mine rattles the floor on some movie scenes. What more could a bass-lover ask for? :daydream:



> Maybe I could hang some panels on the doors themselves?


Sure.



> the main concern is overdampening the room. I listen most critically to music. Maybe some diffusion somewhere?


Looking at your photos I don't think that's a problem.

--Ethan


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## atledreier

I could post an IR plot too, maybe that will give some hints. I have a slight focus problem. The soind is very transparent and holographic, but not very sharp.


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## atledreier

Ok, got my panels just now. Going to get the materials and wood I need to get some cornertraps going. Hopefully done over the weekend. I have moved some stuff around, mainly the subwoofer, and the fronts are symmetrical again. Not sure I like it, I'm going to give it a little time and see if I just need to 'unlike' my old setup..


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## atledreier

Ok, I have 4 cornertraps done. Not as effective as I'd hoped I think, but i'll keep using them and see if I discover the true performance.


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## John N

How would it sound with a nice ottoman instead of the coffee table?


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## atledreier

Send me one and I'll tell you! 

i'm currently considering ceiling treatment. Will try some stuff tonight, both placement, treatment and actually listening to stuff..


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## atledreier

I just finished three more acoustics panels. My four corner chunks were located stacked in the front corners before. Now I have one in each corner, with a 4" panel straddling the corner on top of each of those. That means floor to ceiling basstraps in all four corners! And it really made a difference too! I have another set of small-ish corner chunks that I'm going to finish up today and see if I can find a use for. I'll probably replace two of the corner-straddling panels sith the chucks and use the panels somewhere else. I have another two panels that I need fabrick to cover, so they will come at a later stage. I'll get fabrick tomorrow, probably. Those will go in the ceiling to kill the 1st reflections from LCR. They are also 4".

So now I have 4" panels behind the mains, 3" behind the center, 1,5" on sidewalls, and chunks in all four corners, floor to ceilig! And it sounds rather good to my ears!


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## atledreier

Ok, finished all the materials I have so far. I'd like some input as to the most effective use of the stuff I have. So I'll list it all;

5 pcs 1 1/4" 2'x4'
6 pcs 4" 2'x4'
4 pcs 3'4" corner chunks, 2' face
2 pcs 2'6" corner chunks, 2' face

Currently I have the 4 larger corner chunks on the floor in each corner.
In the front corners I have one 4" panel straddlign the corner on top of the chunks, so they fill floor to ceiling.
In the rear corners (where I have my sonotubes) I have the smaller chunks stacked on top of the larger chunks, with one 4" panel straddling the corner in front of the smaller panel (if that made any sense).

One 4" panel in the first reflection point from the left speaker. This covers the reflection from the center as well, on the left wall.
Three 1 1/4" panels stacked in front of each other, making one 3 3/4" panel on the right wall in the first reflection from the right speaker. I have a door here that prevent me from killing the center channel reflection on the right wall. I'll live.

Two 4" panels upright against the front wall behind the main speakers, and two 1 1/4" panels next to those, toward the center, and the last 1 1/4" panel horizontal behind the center speaker. So my front wall is covered up to 4' high with at least 1 1/4" and up to 4" (some of the front wall panels overlap)

I plan to get another case of three 4" panels and mount them in the ceiling to kill the 1st reflection from the left, center and right speakers.

The room sounds awesome as it is now. Going floor to ceiling really helped, as opposed to the 6' stacks I had before. Ceiling height is just over 7', but covering that last foot really helped.

I feel maybe having the small chunks behind the 4" panels is overkill and could be put to better use, but then the subs are right against those corners and I figure they can use all the absorbtion they can get back there.

Any views or suggestions as to what I should do? I enjoy the room as it is now, but things can only get better, right?


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## atledreier

Ok, been a while since I posted in my thread now.

Recently made some changes to the lineup. Sold the Dalis and got a set of Klipsch THX Ultra 2 speakers. KL650 front and center, and the KS525 dipole rears. Also changed my screen to a 106" Dreamscreen ProCurve with UltraHD screen material. In the process of putting up a new false front wall and get the speakers behind the screen. Also, since the screen is curved I need to make a shallow stage to accomodate the curve. I will make some other changes to the room as well, trying to move my subs up front in the room, behind the screen wall and see if that works out.

I will keep the corner treatments, and probably try to get some more treatment behind the screen now, and some rear wall diffusion to keep the room lively.

I'll post some pictures shortly.


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## hybris

Impressive low end bass response. Time to do some more measurements and waterfalls? It appears you've done some changes since the initial measurements?


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## Kal Rubinson

John N said:


> How would it sound with a nice ottoman instead of the coffee table?


Since the thread is revived, I will respond to this. I replaced an 18"x40" coffee table with a 33"x33" ottoman. However, I opened the bottom of the ottoman by removing the cloth, filled it with OC705 and replaced the cloth. 

Wow! This sits in the approximate center of my room so, in addition to replacing a hard reflecting surface with a soft transmissive one, I think it is damping some midbass (80-100Hz) energy effectively. Comfy, too.


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## atledreier

Hybris: Yes, it is definetly timeto do some new measurements. I've done a lot of changes, all the speakers except subs have been replaced, listening position has changed slightly, and the subs have also moved slightly. I will try with the subs up front again, so I will have to do more measurements and comparisons then. I also have to clean up the room and do some photography.

Kal: Great idea! I will definetly try something like that, my midbass definetly need cleaning up!


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## atledreier

Got around to moving the subs the other day, and did some measurements today.
I used to have the subs behind the listening position, now they are up front, near the corners. I have chunk style traps in all four corners, and got the subs as close to that (touching) as possible.
I sacrifice a little extension for smoothness. It's really not a problem, the subs reach pretty low anyway, just not QUITE into the single digits, and I really like the smoothness of them now. 
Also got the new speakers, obviously. Currently sitting on empty cardboard boxes for stands. I will get proper stands for them, and I'm sure the midrange will clear up a bit. The boxes have a pretty high resonance, well into the midrange. The screen fabric needs replacing as it's just too tight now. I could get more of what I have, but the v2 (free upgrade) is due in Q1 2010 anyway, so I won't bother for now. 

No pictures of the setup yet, it's not in a photogenic state right now, but some measurements should be in order:

The sweetspot measurement. This is with Audyssey active. I never play without it anyway. 6dB/oct smoothing.











I averaged all the measurements Audyssey used (as close as I could get) and averaged them. This graph has no smoothing.











I accidentally made my first measurement with Audyssey DynamicEQ engaged. This was with master volume at -27dB. Adds quite a bit down low... :hsd:


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## hybris

Great low-end response but relatively uneven. How about posting the graph at 15-200hz and no smoothing, easier to see the bass response in detail then. 

Very interesting to see the effect of the Dynamic EQ on the last graph by the way. That's kind of house curvish.


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## atledreier

Here they are.

Notice that the frequency axis is different in the two graphs.
Also not that Audyssey do NOT target a flat-as-possible response for a single location, but rather a best perceived response in all measured positions. Doing all 8 measurements in the same position give smoother measurements but sounds like ... well, not near as good as a proper measurement.

I am very happy with the way it sounds now, and it's pretty much the smoothest I've seen in my room, so I'll stop fiddling with it for a while. 

The DynamicEQ will adjust frequency response to compensate for our ears' varying sensitivity vs levels, so at 0dB master volume the curve will be uncorrected, then as volume goes lower, more and more compensation is added.



First graph is the standard frequency response, unsmoothed and 75dB target. Notice the frequency axis extends to 5Hz.











Waterfall with default settings of the measurement above. You can easily see where my treatments stop working... :hissyfit:


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## hybris

Impressive subwoofers.  


I'd be interested to hear how an Audyssey receiver with Dynamic EQ enabled sounds compared to the curve I've plotted on my own system.


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## atledreier

I'm sure there are lots of people in your area that would love to give you a demo. Or borrow one at your local HifiKlubben store.


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## hybris

atledreier said:


> I'm sure there are lots of people in your area that would love to give you a demo. Or borrow one at your local HifiKlubben store.


Hm, I don't know. I just bought the Pioneer, probably best to not listen to anything else for a while. :innocent:


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## NBPk402

atledreier said:


>


It appears you mounted your projector the same way I did (threaded rod)... I slid aluminum tubing over the threaded rods to dress it up and made my equipment racks the same way as the projector stand.


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## the_rookie

Not trying to revive an old thread, but you said you bought the KL650's?

I was dinking around and saw them on Klipsch site, are they worth the money?


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## atledreier

I no longer have them.

I thought they were great up about 5dB below reference, then they became harsh. Mine were driven by Behringer EP4000, one channel for each, so they should have enough power on tap. They got pretty harsh whenpushed, and I haven't had that happen with any other speakers on the EP4000, so I can only conclude it was the speakers that didn't handle it. 
I loved them up to that point, though. Puncy and detailed, but a little on the small side. There's only so much two 6,5" drivers can do...


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## the_rookie

Yeah I thought the stats seemed a bit underwhelming for the price myself, which is why I asked


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## atledreier

Don't get me wrong, they are excellent speakers, but they won't comfortably do reference.


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## the_rookie

Oh, didn't say that but for the money, it would seem they're better options available.

What are you running now?


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## atledreier

DIY Beyma LCRs

Two 15p80nd and a TPL-150h in each. 200liters, tuned to 45Hz. The have the SPL capability and sound quality that I've been looking for a long time. They are managed by a MiniDSP 10x10 and an EP4000 to drive each of them. Bulid thread is in my sig. inConcert Miles after the guy who originally designed the configuration, I adapted it for frontmounted slotports.


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## erwinbel

atledreier,

Impressive speakers, these inConcert Miles. I am in the proces of building a house with HT myself. Subs are done, LLT as in sig. I was going to build DTQWT-12 by Troels Gravesen for LCR, but I am having doubts that they will do reference level without desintegrating. Problem is the midrange JA8008. Troels wrote on his website that a 95 dB speaker should not be fed 400 solid state Watts. Which is exactly what I have (Emotiva XPR-5)...

So I am looking for other options, maybe buying active speakers such as the new Emotiva Pro Stealth 8 (also uses the Air Motion type tweeter). Or build an other speaker all together, so your's got my attention. Seems like TangenAVDesign is no longer in business though? I also think going active would be more complicated. Do you think an electric noob like me could pull it off? I see you're an engineer..

Also, what are your surrounds?


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## atledreier

My surrounds are Klipsch RF82 for now, bass managed at 50Hz.

It is less complicated to go active. The crossovers can be a pain to get parts for, they are expensive and much less accurate and flexible than an active system. Active will require two amplifier channels per speaker, though, and a DSP. I currently use the MiniDSP 10x10HD DSP unit and it is excellent. By far the best DSP unit I have had in my system. Very easy to set up, and you have 8x8 in and outs that you can configure freely.

The Miles speakers do require a subwoofer though. They are tuned to 45Hz which mean they start to roll off at around 50Hz. Nice for music, but a little lean for movies. The impact and punch is phenomenal though. You can really get that 'live' sound where even male voices are felt in your chest, and acoustic instrument REALLY shine on these babies. They are also effortless even at way above reference, and so sensitive that even modest amplifiers can perform their best.


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## erwinbel

atledreier said:


> My surrounds are Klipsch RF82 for now, bass managed at 50Hz.
> 
> It is less complicated to go active. The crossovers can be a pain to get parts for, they are expensive and much less accurate and flexible than an active system. Active will require two amplifier channels per speaker, though, and a DSP. I currently use the MiniDSP 10x10HD DSP unit and it is excellent. By far the best DSP unit I have had in my system. Very easy to set up, and you have 8x8 in and outs that you can configure freely.
> 
> The Miles speakers do require a subwoofer though. They are tuned to 45Hz which mean they start to roll off at around 50Hz. Nice for music, but a little lean for movies. The impact and punch is phenomenal though. You can really get that 'live' sound where even male voices are felt in your chest, and acoustic instrument REALLY shine on these babies. They are also effortless even at way above reference, and so sensitive that even modest amplifiers can perform their best.


I am still undecided what to get or build, but I keep coming back to the inConcert Miles! Your suggestion to go active did put me off at first, but even the designer, Mr Tangen, commented somewhere (Norwegian website I believe) that they sounded superior when steered active. And your fellow Norwegian, BEF-NO, also went active with the Miles, correct? That's three! And the Behringer DCX is affordable enough at 277 euros. Just need more amp channels... Behringer is the way to go for sure to split the signal? And on top of that you use the MiniDSP? So the setup is AVR > MiniDSP > Behringer DCX 2496 > 6 amps > 3 Miles LCR?

Thanks for the info!

No worries for subsonics, sir: I got two LLT ready...


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## atledreier

I ditched the DCX for the MiniDSP 10x10HD. It's a better unit. Less noise and easier to setup.


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## erwinbel

Thought so, why would he need both? I'll have to take your word on how easy it would be to set up the MiniDSP because I wouldn't know where to start...

I have a lot more questions but I notice the Miles is mostly a Norwegian affair. I did browse through AVforum.no but my Norwegian language knowledge is limited to what I gathered from watching Varg Veum and Lillyhammer!

Do you still stand behind your option to do a MTM layout, because it seems the way to go for me also. That way, the whole (center) speaker can be behind the AT screen, put on a small stand or alternatively make a taller, shallower shape. 

You don't consider buying or building surround speakers that are more like the Miles? I am thinking of using Emotiva stealth 8 for surround. They also have the same type of tweeter as the Beyma TPL-150 (but without horn and only half the size).


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## atledreier

I have considered rears, and at some point I probably will. As it is, I'm rebuilding my cinema in a new house, so it takes quite some time to get settled in and learn the new room. My current layout means I have a door right beside the primary listening position, so side surrounds aren't possible. The klipsch speakers do a decent enough job with so much power available and bassmanaged at 50Hz. They even match sonically to some degree. If you read BEF's thread, he is using both side and rear surrounds made with the same setup, but only a single bass driver in each. Having such a matched setup makes for incredible homogenity.


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## erwinbel

Ayon Audio presented their new (prototype) Blackfire XS speaker at High End Munich. Here's a show report in German, it's the last item so scroll down:
http://flatworld.welt.de/2013/05/10/bericht-von-der-high-end-hifimesse-in-munchen-tag-2/

Guess which horn-loaded tweeter it uses? :T
http://flatworld.welt.de/files/2013/05/image7.jpg

Both woofers are actively powered and DSP'd. The 55 Watt mono tube Ayon Vulcan II amps you see are powering the tweeter and midrange.

The speakers are 50,000 euro / pair
The amps are 29,000 euro / pair

Crisis? What crisis? :spend:

Anyway, more proof that the Beyma TPL 150H is very special indeed. The reporter writes that the bass is to heavy for his taste, but that's rectified easily enough using the DSP, I'd recon.


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## atledreier

That's a pretty nice setup! 

I have currently flipped the room to accomodate a 4 driver IB3 build, so I'm on a whole new journey regarding acoustics in this space. Also built a new wall in there, so the space is smaller, and different.


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## erwinbel

atledreier said:


> That's a pretty nice setup!
> 
> I have currently flipped the room to accomodate a 4 driver IB3 build, so I'm on a whole new journey regarding acoustics in this space. Also built a new wall in there, so the space is smaller, and different.


Cool, I am sure we see pics sooner or later.

BTW, in the end I decided against building a version of the inConcert Miles. The dispersion of the Beyma TPL150H air-motion tweeter with horn is to narrow compared to the SEOS waveguides with a CD tweeter. I will post pics, the building has just began last weekend.


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## atledreier

Apparently I can no longer edit the OP, so I'm going to have this thread closed and start a new one. It is a new room in a new house compared to the OP anyway, so it's a warranted change.


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