Room Acoustics

[iQ Speakers]

I don't know how to break it to you Dave, but I think that's exactly what we have been saying, so on this occasion your rant was completely superfluous.

Yeah, I know, I was in a bit of a strop.

However the real point I was trying to make is that any kind of room treatment is quite out of the question for an awful lot of people, in many cases even elementary matters of speaker and listener position are not addressed.

I don't get into as many peoples homes as when I was a dealer, but I am still asked as an 'expert' (sic) to offer opinions or to sort out issues with peoples systems. Current hi-fi marketing trends really do not help and decent advice from a dealer seems remarkably absent.

The result being that many of the setups I see are hopelessly unsuited to the room and, just as importantly, the limitations of setup and positioning. The main problem here remains excessive bass, bass sells and speakers, particularly in the budget/mid-fi sector of the market are designed to deliver lots of it, whether on the recording or not seems not to matter.

No problem i had a bit of an issue with the saftey brigade lacking knowladge about cleaning amps!

Just shows i asked for room sizes, speakers installed and if there was an issue, 2 or 3 replies one from Matt49 with his Corby trouser press speakers that i have no idea about! So peeps are not realising size is alway best. I had an extremley interesting if a bit instense ,day with Ivan at IPL Acoustics most of it was chosing the correct size speakers for the size of room.

 

[ellisdj]

Good few points made in this thread. Room acoustics play a massive part in the perception of the sound of your HiFi. However unless you're building a home recording studio with a very big budget, for many of us it's going to be a balancing-act between cost, practicality and domestic acceptability. Simple improvements can be accomplished cheaply or at no cost: rugs, decent carpets, thick curtains, common sense placing of furniture, speakers and reflecting items. You want a cheap change? Try moving your seating position forward or back by as little as 6". You'll be amazed. The room size also plays a massive part as well, particularly with bass frequencies, and unfortunately that's often unchangeable. Many people are sitting in a room where the distance from the speaker to the wall it faces isn't even long enough to accomodate one cycle of a 60Hz sinewave, let alone anything lower.

Cost shouldnt be considered a factor - a whole room costs far less to treat than a good pair of speakers - the benefit far outweighs the cost more than anything you can spend your money on.

Practicality is obviously more of an issue - its amazing what you / swmbo can get used to though - and with a bit of effort it can become part of the decor and look nice.

I expected everyone to hate my cinema room - but so far nearly everyone has said they actually really like it - which was a surprise. I couldnt care less about that tbh but its true

Is quite dark in there tho *smile*

 

[matt49]

I don't get into as many peoples homes as when I was a dealer.

Phew!

Just shows i asked for room sizes, speakers installed and if there was an issue, 2 or 3 replies one from Matt49 with his Corby trouser press speakers that i have no idea about!

Hey! Watch your tongue, young sir!

There is, of course, a different way of addressing this. Let's assume davedotco's Doomsday scenario applies: a small to medium-sized room with speakers and listening position bang up against the walls and no prospect of moving things around.

What to do? Well, you could buy a weedy, anaemic little pair of speakers, such as Dave prefers. AVI? Perfect! No bass at all! Alternatively, you could buy speakers that are designed for boundary placement. We went through this whole boundary placement thing in the '80s with the Flat Earth ideology. People seemed to like it. It can work.

Another point: it's not a question of absolute size. (Major Fubar has made this point well.) I've heard big speakers sound great in a very small space. The problem isn't absolute size; the problem is the wrong size. And one way or another, this can almost always be resolved by using DSP for LF correction.

 

[iQ Speakers]

My apologies Matt

could not resist it was a private joke with a fellow friend of yours and a forumite, if we didn't think they were good, I couldn't do the joke. Besides I want you to do one of your detailed reviews on my speakers once it get a demo pair built.

 

[matt49]

My apologies Mattcould not resist it was a private joke with a fellow friend of yours and a forumite, if we didn't think they were good, I couldn't do the joke. Besides I want you to do one of your detailed reviews on my speakers once it get a demo pair built.

Well, you're very naughty, both of you! *aggressive*

I'd really like to hear your speakers. For some reason I'm thinking you're in S. Wales -- have I got that right?

 

[iQ Speakers]

Good God no! Cheltenham, you?

 

[CnoEvil]

Good God no! Cheltenham, you?

....and there's me thinking how well "Boggit" would sound in a Welsh accent!

 

[matt49]

Good God no! Cheltenham, you?

West London, but in Glos every other weekend, just up the escarpment from Stroud.

Are you in e-mail contact with Mac? If so, he could send you my e-mail address.

 

[iQ Speakers]

Oh excellent about 20 mins away, yes I am, I'll ask him to to send it over. Oh he's now known as DJ Mac as he's landed a DJ role on a radio station!

 

[steve_1979]

Room: Irregular shaped 7m x 5.5 x 4.5m

Speakers: AVI DM5 plus AVI subwoofer.

Generally no big problems. The room is a bit bright with too many large flat surfaces but this is not an issuse from my listening position which is near field from 1.5m away. There are a few peaks and troughs in the low frequencies depending on where in the room you listen from but again nothing too major and from my listening position the bass is just right apart from a pretty major dip at about 40-50Hz.

The DM5 also sound good no matter where in the room they are placed. Whether on stands in a well placed position, near or far away from a wall/corner or even just plonked on a cardboard box in the middle of the room.

Thats great feedback - 40 - 50hz dip seems pretty common. I have a peak bigger than eifel tower at 68hz is a real bugga because of my room - unlistenable

What about the decay? Have you measured the decay time of your bass and how even is it?

This is the same for the rest but measured via RT60 (only way I know whats what) - what RT60 time and how even is it?

I haven't had a chance to measure the decay because I don't have a good enough microphone. I have a cheap Logitech microphone for gaming but it's designed for speech and I wouldn't trust its low frequency performance for measuring or setting up a subwoofer. Going by ear with music the decay seems very good with no noticable boom, drone or echo effects. In fact the bass from the DM5's plus sub is the best that I've ever heard (I know, I know, AVI fanboi talk but I swear it's the truth ) and it can be described using the usual audiophile terms like 'tight' 'punchy' and 'solid'.

The subwofer currently has plenty of output between 30-40Hz and from 50Hz upwards with just a dip between 40-50Hz. Dips in frequency response aren't much of an issue unlike peaks which are much easier to hear as sound awful so I'm not too worried about it. I doubt that DSP would make that much difference as it sounds reasonably flat with a sine wave sweep (apart from the dip) and DSP EQing only reduces the peaks but doesn't attempt to boost the dips.

Subjectively I'd estimate that the DM5's produce between 90-99% of the bass anyway.

 

[steve_1979]

Could i sugest people post room sizes and the speaker they own along with or without room problem.

PMC DB1i across the room. No problem. IPL Acoustics M1TLm (5" driver, ribbon tweeter small floorstander) across the room No problem.

I think you would see a pattern emerge of over done speaker choice causing problems.

+1

It would be interesting to hear about a few other peoples rooms, speakers and acoustics issues. Any takers?

 

[MajorFubar]

Just for laughs, here's an old picture of my listening area (ignore the speaker on the desk that's not normally there and the subwoofer in this photo is the old Neutron sub which has now been replace with the larger ADM9 sub. I've also put wooden chopping boards under the stands to raise the tweeters up closer to ear level).

As you can see there's some very high tech acoustic treatment going on here. I've added two small cuddly toys specifically positioned at the 'mirror points' on the front corners of the desk and another larger cuddly tiger toy on top of the subwoofer which is another 'mirror point'. It looks funny but they do help break up the desk reflections which are a common problem with near field computer setups and it does seem to improve the stereo image a fraction, although this may just be the placebo effect at work. Obviously this is just to break up early mid-range and treble reflections and makes no difference to the bass.

The two cuddly toys on top of the speakers are not high tech acoustic treatment. They're there just to stop the cats from sitting on the speakers.

What an excellent little set up. Very nice indeed

 

[steve_1979]

Just for laughs, here's an old picture of my listening area (ignore the speaker on the desk that's not normally there and the subwoofer in this photo is the old Neutron sub which has now been replace with the larger ADM9 sub. I've also put wooden chopping boards under the stands to raise the tweeters up closer to ear level).

As you can see there's some very high tech acoustic treatment going on here. I've added two small cuddly toys specifically positioned at the 'mirror points' on the front corners of the desk and another larger cuddly tiger toy on top of the subwoofer which is another 'mirror point'. It looks funny but they do help break up the desk reflections which are a common problem with near field computer setups and it does seem to improve the stereo image a fraction, although this may just be the placebo effect at work. Obviously this is just to break up early mid-range and treble reflections and makes no difference to the bass.

The two cuddly toys on top of the speakers are not high tech acoustic treatment. They're there just to stop the cats from sitting on the speakers.

What an excellent little set up. Very nice indeed

Thanks.

When I can be bothered to clean up all the clutter and mess I'll take some proper pictures using my girlfriends camera. There are a few changes since that photo like the new subwoofer, the slightly raised speakers, the cables have been tiedied out of sight and I'll include photos of the head-fi setup and Yamaha AVR which is very neatly hidden away in a small antique wicker table which is perfectly sized to fit it.

 

[steve_1979]

Just for laughs, here's an old picture of my listening area (ignore the speaker on the desk that's not normally there and the subwoofer in this photo is the old Neutron sub which has now been replaced with the larger ADM9 sub. I've also put wooden chopping boards under the stands to raise the tweeters up closer to ear level).

As you can see there's some very high tech acoustic treatment going on here. I've added two small cuddly toys specifically positioned at the 'mirror points' on the front corners of the desk and another larger cuddly tiger toy on top of the subwoofer which is another 'mirror point'. It looks funny but they do to help break up the desk reflections which are a common problem with near field computer setups and it does seem to improve the stereo image a fraction, although this may just be the placebo effect at work. Obviously this is just to break up early mid-range and treble reflections and makes no difference to the bass.

The two cuddly toys on top of the speakers are not high tech acoustic treatment. They're there just to stop the cats from sitting on the speakers.

 

[ellisdj]

This is my room setup - front

Back

Even with all that there are still acoustical issues - huge peak at 68hz and few nulls. With nothing in this room sounds pretty awful IMO

Front right speaker response still isnt great 200 - 400hz - but better than before. Left speaker response is excellent. Sub response after a bit of dsp and setup how I like it - hard knee house curve - minimum eq as possible is pretty good with minmal nulls - still nasty one about 75hz

But decay is excellent and even down to about 90hz which is excellent and creates a lovely room envrionment for good sound.

There are a few errors I made with this panelling setup and I will fix them later.

But the sound in here is very different to an empty room - there is no going back for me.

 

[jonathanRD]

Could i sugest people post room sizes and the speaker they own along with or without room problem.

PMC DB1i across the room. No problem. IPL Acoustics M1TLm (5" driver, ribbon tweeter small floorstander) across the room No problem.

I think you would see a pattern emerge of over done speaker choice causing problems.

+1

It would be interesting to hear about a few other peoples rooms, speakers and acoustics issues. Any takers?

Room is 5m x 4m with speakers across the 4m wall. Speakers are roughly 1m from back and side walls and 2.2m apart. A very large L shaped sofa is 1m from the opposite wall with large window along it. So I sit almost at the tip of the equilateral triangle with a large shaggy rug in between. However, the room has very little other furniture, mostly bare walls and on one side there is a 8ft floor to ceiling mirror (the room was originally a dance room too). There are a couple of cushions on a piece of furniture on the right-hand wall in the main reflection point and two strategically placed CD/DVD stands in front of the mirror on the left-hand wall. And there is a slight echo.

But with my new RS5's - the sound is fine - unless my ears are c***.

So, before I upgrade my amp, I have a few little projects in mind, but I want to be able to measure the progress. Any simple tips on what I need to purchase to measure the accoustics in my room?

 

[iQ Speakers]

So a reasonably large room with medium sized speakers with very slight echo problem. Sparsely furnished. I'm sure if you went larger more issues, smaller and that slight echo might disappear.

 

[jonathanRD]

So a reasonably large room with medium sized speakers with very slight echo problem. Sparsely furnished. I'm sure if you went larger more issues, smaller and that slight echo might disappear.

haha - no we get a slight echo when we talk - so we'll have to talk quietly*wink*

 

[iQ Speakers]

That reminds me a simple test if you clap in the room and you get an Echo you may have issues, go try.

 

[jonathanRD]

That reminds me a simple test if you clap in the room and you get an Echo you may have issues, go try.

Yep - a very slight echo when I clap my hands. I have some plans to gradually soften the room. The mirrors don't help but it is unlikley that we are going to remove them, and they help make the room much lighter. On a positive note, the softening up process may improve the sound of my system, which is good considering I don't think I have any problems at present.

 

[steve_1979]

That reminds me a simple test if you clap in the room and you get an Echo you may have issues, go try.

Yep - a very slight echo when I clap my hands. I have some plans to gradually soften the room. The mirrors don't help but it is unlikley that we are going to remove them, and they help make the room much lighter. On a positive note, the softening up process may improve the sound of my system, which is good considering I don't think I have any problems at present.

The mirrors probably help a little bit by breaking up the large flat wall surfaces. Putting up a few framed pictures and adding furnature like bookshelfs can help with this type of thing too.

A thick rug or two hung on the walls may help reduce the echo too. These will be most effective if they can be placed at the 'mirror points'.

 

[jonathanRD]

So - I had a 1970's Nathan sideboard that lived in my shed for 10 yrs. Using the bottom half of it, I sanded it down, re-stained it black and waxed and polished it. It looks like a new piece of furniture, matches the other black gear in the room, and nicely stores some vinyl, CD's and DVD's. It has two cushions placed on top in one of the reflection points. The top half of the sideboard I dismantled and stored in my shed again. I am going to re-attach part of the top half (about 18 inches high) and cover it in accoustic wool/foam and finish it off with some black accostic material. This will provide a 6ft x 1.5ft accoustic panel in the right-hand main reflection point. I am then going to use some of the other pieces, sand and re-stain them and build a floor-standing CD/DVD cupboard and attempt to incorporate some more accoustic panels against the mirror to cover the left-hand main reflection point. I will still have some shelving left over to place on one of the walls. I also have some picture rails to fit, more pictures to hang, and then I might look at building some more accoustic panels/bass traps for the back wall. The walls are bare so at some point I will cover with wall-paper and fit coving. That'll do for starters *good*