Speaker placement in difficult room, need help.

**Bluum** · **01-25-08, 03:51 PM**

Hi, first of all, I need to say that I am Norwegian, so if my English i bad, that's why

Then to the point.
I have a 2.0 stereo consisting of a NAD C320BEE integrated stereo amplifier, and a pair of B&W DM602 S3 bookshelf speakers.

In my room, I have trouble placing the speaker without getting huge peaks and dips in the bass/low midrange area.
Most anoying is the constant peak at aprox. 45Hz, and an large dip stretching 25-40Hz somewhere in the area between 60 and ~140Hz.

This is a ScetchUp drawing of the room which shows the meassurements of the room:
index3.gif
(More pictures can be added later if you want/need them)
An important thing to know about it is that it lies in a basement; which means that all the walls are concrete, (the foundation of the house).
All of the walls are "covered" with regular 17mm thick wooden panel, exept the longest wall, which only is painted with some paint with little plastic balls in; which gives it a rough surface.

On the wall oposing the speakers, I have placed a bookshelf to diffuse the soundwaves, for reducing reflections behind me.
The speakers are currently standing on an old pair of Philips speaker, but that wil be replaced with a sand-filled pair of stands with spikes. I'll just have to make them first

The TV-table leaves about 50,5cm clearing on each side, and that is where I can place the speakers.
Of course I can place the a little in front of it; but not too far, and not too close together, that'll block the TV.

I have a limited space to place the speakers on, and I have tried most of the positions that I feel might could be good.
I've tried close to the sidewall, as far from the sidewall I can get, far away from the backwall, close to the backwall and a lot of places in between.

What I observed when I did a systematic measurement, is that moving the speakers back and forth just affects the amount of bass below ~65Hz, and moves the huge dip from one place to another; never reducing any of them.
Moving closer and further away from sidewall mostly results in changes above ~150Hz. Closer to the wall increases volume and causes instability, (peaks and dips).

Here is my current graph, which is a quite typical one:
111222333444555666777888999.jpg

Now over to what I feel is wrong or missing.
First of all; i miss the feeling, the groove in the music. I want to feel my chest compressing, (slightly at least), by the drums. Not like in a night club or at a concert; but I want to feel the music, not just hear it.
My computers soundcard (Creative X-fi XtremeMusic) or my jack<RCA cable (Argon 5005) could might have something to do with it, but it is most likely the room, since I get aproximately the same graph when I do a manual "sweep" using my PS3 as the sound source.
It shouldn't be the music files, because I mostly use FLAC and original CD's, if I bother to insert them.
Besides that, I feel there is a little "acoustic delay" ,(in lack of better words ...), but I've ordered a six-pack of Rockwool "Acoustic plates". I can't seem to find theese on the .com page, so I'll link you to the Norwegian one: http://guide.rockwool.no/sw14613.asp

So in a couple of weeks I'll get six 50mm thick plates, which I'm gonna damp the first reflection points on the wall and ceiling with.
That should take care of the midrange and treble, and give me a more pleasant sound.
Right now I have a little noise because of the reflections in the room.

But what I ask you to help me with, is finding a good place to put the speakers, and some general tips on how to optimize the listening room more.

If you feel there is some info missing, or if it's just something you want to know, please post

**Bluum** · **01-27-08, 07:54 AM**

Bump ...

**nova** · **01-27-08, 10:18 AM**

Hi ya Bluum,... First let me say Welcome to the Shack.

I don't know much about this stuff but, have you tried moving maybe the bookshelves? Maybe some rugs here and there on the floor? You didn't say, but from your sketch, it looks like you have a hardwood floor.

**Bluum** · **01-27-08, 12:21 PM**

Yes, it's a sort of parquet.
I'm waiting for money to buy a table and a carpet to have in front of the sofa.

But my main problem is the bass; and I wonder if there is anything smart I can do; or if it is a program I
can use to calculate the optimal placement of the speakers.
I don't think a carpet on the floor, or moving the bookshelf a few centimetres wil affect that.

The room height is 2,2m by the way; and my speakers stand on a pair of other speakers, which are 48,5cm high.
And also; the room isn't rectangular, but more "L"-shaped. And that makes the general rules for speaker placement dificult to follow, and the results are not uplifting either.

Another thing worth mentioning is that I tried to place the speakers on tom of a table, and that gave me a completely different sound.
The midbass (100-200Hz) was boosted, and the bass area (~-100Hz) was a little smother. But the deep bass (35Hz and down), was reduced compared to when the speakers were placed on the speakers.
From this, I conclude that the "stands" mean a lot. Even though the speakers came about 12-13cm higher on the table; I don't think that made the difference.

So within this new week; I'll make a pair of stands. 2x2" framework, spikes under and sand inside.
That should help a litte, I hope.

But would you say that a subwoofer is the only way to go if I want a more flat frequenzy response?
Any suggestions?
B&W ASW608 perhaps?
Or an XTZ 99 W8.16?

**Sonnie** · **01-28-08, 12:01 AM**

Hello Bluum and welcome to the Shack!

I don't believe you are ever going to realize what you are looking for in the bass region without a sub. Even then you may still need to equalize the sub response to get it to flat.

I'm somewhat bias on sub choices and for good reason... SVSound.

**Bluum** · **01-28-08, 12:12 PM**

SVS might be a little expensive for me; and it wil probably go a little deep for my room.
And isn't SVS more of a "cinema"-sub?
I use mye stereo for music, and allmost never for movies. Besides; I prefer closed subwoofers

I am begining to realize that getting a flatter curve than what I have now wil be difficult; but I'm willing to try spikes and som heavy stands before I give up.

At the moment, I am poor, so anything expensive is a few moths into the future

Anyway, I visited my local hi-fi shop and listened to some Thule and NAD amplifiers that I might trade my current one for.
That might help I think.
According to what I heard, NAD was "deeper" and "heavyer" than the Thule, that was more "hard" and "fast". So a Thule amp. would suit me fine. Specially with a closed sub from B&W.
Money is the problem.
The cheapest sollution with Thule IA60 and B&W ASW608 cost about 9000NOK inclusive cables; and I paid 6700NOK for my current stereo :P

But back to the room.
Is there a computer program, (a free one is preffered), that can calculate a rooms "frequency response"?
I know there is one called CARA, but that is to expensive for me.

Thanks for answering you guys

**Sonnie** · **01-28-08, 12:27 PM**

SVS subs are just as musical as any other subs on the market... better than most. Check out the Subwoofer Tests forum for the latest info.

Spikes and stands don't make more bass. You could equalize the bookshelf speakers, but pushing them past their limits will only increase distortion.

The NAD you have now is going to provide those speakers all they will produce. Unfortunately buying another amp isn't going to help you. You could put either of those amps in your room and the response is most likely going to look the same and the speakers are most likely going to sound the same.

For deeper bass extension you will need a sub. SVS has the SB12-Plus that is sealed if you are looking for a sealed sub. Depending on the finish they run from $699-799. Not sure what that translates into your currency.

**brent_s** · **01-28-08, 12:55 PM**

Not much time at the moment...couple of quick hits.

Google (or search engine of choice) "room mode calculator" or something similar and you'll find some pages that will attempt to calculate room peaks/nulls for you. That 45hz peak is almost assuredly a mode. You describe an very acoustically challenging room...hard walls/floors/ceiling.

B&W specs the 602 with an f3 of 58hz. Looks like you're getting quite a bit of bass help from the room already, assuming relatively accurate readings from REQW.

Sonnie, consider moving this to the acoustics forum?

-Brent

**Bluum** · **01-28-08, 01:38 PM**

Converting USD ($), to my currency won't give a correct idea of price. (699-799$ equals about 4-5000NOK)
Unfortunately, my government have a tax on everything you buy.
It is at hillarious 25%; so if something cost 100NOK, you'll have to pay 125NOK.
It's sick, but when it came in the mid 60's, I think, they said it was temparary, and it was 12%. Which was OK, since we were in a little money-crisis, but they've gotten so greedy that they doubbled it to 24%, and made it include food. And a little later, they changed it to 25%, to make it easier to deal with.

So for everything you buy or pay for in Norway, (even services like taxi), the government gets 25% of it's value

As an example; i just bought a new TV for 15 000NOK, which means that the government made 3000NOK just because I bought a TV

That's about 500-550$ more than I needed to spend. (1 USD equals about 5-6NOK).

But back to speakers

The quality of the bass is more important than the quantity of it. A quite flat frequency response lying 3dB under target value @ 40Hz is OK.
Bass below 30Hz is not that important to me as the rest of the bass.

A new amplifier won't drastically change the frequency response, that's true; but it will change tha sound and the clarity/quality of the sound.
The main reason that I wan't to get a different amp, is that my amps volume wheel is a little inacurate. Just a little movement can increase the volume quite a bit; and at low volume, there is inbalance between the left and right side volume.

Equalizing to increase bass level some places probably won't happen, but to reduce it might happen. Unfortunately a good EQ cost money, money that I don't have now :P

brent_s: Thanks for the tip; i'll spend some time on google tonight

Thanks for still helping!

BTW, SVS SB-12 Plus is priced just below 1200$, but is now on sale for about 1100$ ...

**Sonnie** · **01-28-08, 01:53 PM**

Quote:

Bluum wrote:

Unfortunately, my government have a tax on everything you buy.
It is at hillarious 25%; so if something cost 100NOK, you'll have to pay 125NOK.
It's sick, but when it came in the mid 60's, I think, they said it was temparary, and it was 12%. Which was OK, since we were in a little money-crisis, but they've gotten so greedy that they doubbled it to 24%, and made it include food. And a little later, they changed it to 25%, to make it easier to deal with.

So for everything you buy or pay for in Norway, (even services like taxi), the government gets 25% of it's value

Sounds like robbery. :raped:

Quote:

Bluum wrote:

The quality of the bass is more important than the quantity of it. A quite flat frequency response lying 3dB under target value @ 40Hz is OK.
Bass below 30Hz is not that important to me as the rest of the bass.

About the only way I could imagine you ever getting a flat response to 40Hz with those bookshelf speakers is to equalize them. The 45Hz and 58Hz peaks are going to be trouble until equalized. A sub could change that easily by crossing over the mains at 80Hz and then equalizing the sub is something that is inexpensive to do with a BFD for $100-150.

Quote:

Bluum wrote:

A new amplifier won't drastically change the frequency response, that's true; but it will change tha sound and the clarity/quality of the sound.

I doubt any other amp is going to best the NAD as far as quality. Changing the sound will require coloring the sound.

Quote:

Bluum wrote:

The main reason that I wan't to get a different amp, is that my amps volume wheel is a little inacurate. Just a little movement can increase the volume quite a bit; and at low volume, there is inbalance between the left and right side volume.

That may be a good reason to get a new amp... and/or the need for a sub pre-out if your current NAD does not have one.

Quote:

Bluum wrote:

BTW, SVS SB-12 Plus is priced just below 1200$, but is now on sale for about 1100$ ...

Prices must be higher in Norway.

**Bluum** · **01-28-08, 02:36 PM**

Yes, it is more expensive in Norway.
That is why so many people order stuff from the United States; even with the oversea shipment and customs, it is considerably cheaper.
If you can travel to USA to buy it yourself, it is even cheaper.
I know a lot of people who have traveled to the US and brought back a couple of gitars, sold them (unused) for less than retail price in norwegian shops, and still made money of it.

I just now tried to move the speakers so that they're not longer symetrically placed in the room, but placed more to the right.
I feel that I have a better frequency responce, but my measurements show little difference.
I'll try to fine-tune it some more and come back with a graph when I am pleased enough to take a brake for the day

**Bluum** · **01-29-08, 03:07 PM**

OK, I have tried different assymetric setups, but can't seem to get any big improvements.
So I thouht it would be fun to see which side that caused the most trouble, and if there was a difference.

So I placed the speakers as symetric as I could, and first ran a sweep on both, then a sweep on the right speaker, followed by one on the left speaker.
With the middle of the front about 30,5-31cm from the sidewall, a little more than 60cm from the backwall and a quite similar toe-in, I meassured them.

Results:
Both speakers
begge.jpg
Right speaker only
høyre.jpg
Left speaker only
venstre.jpg

The difference suprised me, and I now feel that I should focus on the left speaker, and find a good position for this one; and then try running in stereo again.

What do you think of that idea?
I'm not gonna do it now, because it is 22:00 here now, and I've had a long and hard day, but some viewpoints could be nice annyway

**blake18** · **01-29-08, 10:27 PM**

Quote:

Bluum wrote:

SVS might be a little expensive for me; and it wil probably go a little deep for my room.
And isn't SVS more of a "cinema"-sub?
I use mye stereo for music, and allmost never for movies. Besides; I prefer closed subwoofers

I am begining to realize that getting a flatter curve than what I have now wil be difficult; but I'm willing to try spikes and som heavy stands before I give up.

At the moment, I am poor, so anything expensive is a few moths into the future

Anyway, I visited my local hi-fi shop and listened to some Thule and NAD amplifiers that I might trade my current one for.
That might help I think.
According to what I heard, NAD was "deeper" and "heavyer" than the Thule, that was more "hard" and "fast". So a Thule amp. would suit me fine. Specially with a closed sub from B&W.
Money is the problem.
The cheapest sollution with Thule IA60 and B&W ASW608 cost about 9000NOK inclusive cables; and I paid 6700NOK for my current stereo :P

But back to the room.
Is there a computer program, (a free one is preffered), that can calculate a rooms "frequency response"?
I know there is one called CARA, but that is to expensive for me.

Thanks for answering you guys

A little too deep for your room? Wrong there buddy! You can never ever EVER have a sub that goes too deep or too loud. It is better to have too much and not need it, then to have too little and need more.

**Sonnie** · **01-29-08, 11:23 PM**

Measuring one speaker at a time really doesn't tell us much. You probably won't be playing just one speaker at a time. Move the speakers around... and measure both, since you are always listening to both and will always need to see the interaction between the two.

I know I'm being somewhat pessimistic, but I doubt you are going to find a suitable location for both speakers and be able to keep imaging and sound stage in tact. Your best solution is going to be a sub, even if it's an inexpensive sub that only extends to 30Hz or so, since you say that's all you really need. Get the sub, crossover those bookshelves at 80Hz and equalize the sub with a BFD. You'll have everything you are looking for.

**atledreier** · **01-30-08, 03:26 AM**

BTW, www.Lsound.com sell SVS in Norway. I agree with the above, a sub is needed in almost any setup.

You seem to be a Hifi-Klubben man. You'll like my setup, I've worked there 12 years...

If you live anywhere near me (Sandnes, Stavanger), come have listen!

**Bluum** · **01-30-08, 09:25 AM**

I couldn't agree more with you blake18, that's my philosophy

I'll try moving the left speaker and see what I can get out of that one.
I won't keep on for too long, but I would like to see the effect on moving that one.

I know where L-sound is; they have their main office in my town, Arendal

That's where I bought my RadioShack by the way.
Although I would love to hear your system atledreier, I'm not willing to drive for seven hours to hear it :P

A subwoofer will be bought sometime in the future, but I wan't to listen closely to it before I buy it. And HiFi Klubben (the importer and seller of B&W in Norway), hsn't got any B&W subwoofers left.
And they won't get any untill the begining of March, pluss minus a coupple of weeks.
So when they get in in store, I'll book a demo with speakers and amplifier similar to my own.

So expect some graphs in the next post, if I see any big difference

**Bluum** · **01-30-08, 04:13 PM**

It's two posts in a row, sorry if that causes any inconvenience.

I have moved around the left speaker a couple of hours, and haven't found a singel half-good spot to put it.
But I did get av very interesting grapf when I moved the speakers a litte bit.

When I moved the speakers to the long wall of the smal part of the room; I got an allmost straight response from ~30Hz to ~50Hz; a "mountain" starting av ~55Hz, peaking at ~65Hz (+13dB), and decreasing smothly down to ~82Hz (-7dB).
There was some dips in the area from 77Hz to about 155Hz.

Heres the best graph, with speakers front about 36cm from the back wall:
dfghnj.jpg

I liked the sound, allthoug the big peak bothered me a little.
But other than that I felt it was good.
The only disadvantage I can find with this speaker setup, is that I now have to sit 170cm away from my 42" TV :P

I have an equalizer on the soundcard that can tune the 62Hz frequency, so I'll try lowering this one tomorrow. Now it is too late to play, most of the house has gone to bed.

**atledreier** · **01-31-08, 01:35 AM**

How is 170cm from a 42" plasma a disadvantage? You're right in the optimal zone for that screen size, unless it's a very poor plasma. You'll love it!

**Bluum** · **01-31-08, 09:37 AM**

It's a Panasonic TH-42PZ70 with full HD, so when I use my PS3, its great.
But for DVD-movies, it is on the edge of what I find acceptable.

I'll se what I can do about moving the setup to the large area of the room.
But before I move all of it, I have to test the sound response, so I'll try to set up the speakers on the wall where the largest bookshelf now is. The wall opposing the one where the stereo is on the picture.

Som graphs will be uploaded later in the evening, hopefully.

By the way; look how perfect the response from ~30-~48Hz is

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