Room Treatment for Summits

[Neil H]

I have had my Summits for about 6 months. They are now putting out some really good bass but at times I feel the sound is a bit muddied.

I can turn down the bass on the speakers to get a really clean sound, but I prefer the solid bass I am getting at the 25hz 0 setting and 50hz +3 setting. The sound can also be a bit thin with the 50hz setting turned down too much. I think the problem is that I don't have any sound absorbtion on the front wall which is made of high density gyprock.

I have never delved into the issue of room treatment that much in the past but the Summits seem very sensitive to all kinds of adjustments and I am confident further improvement in the sound would result from room treatment.

My room is about 7 metres long and 5 metres wide with heavy curtains down both sides of the room. The speakers are positioned on concrete about 2.5 metres out from the front wall and about 2 metres apart.

Would appreciate some advice.

 

[JohnA]

A picture would be useful I'd think, have you got one in the 'Member Systems' part of the forum?

 

[twich54]

My room is about 7 metres long and 5 metres wide with heavy curtains down both sides of the room. The speakers are positioned on concrete about 2.5 metres out from the front wall and about 2 metres apart.

Given your room dimensions I'm wondering why your speakers are positioned so close together ? Distance out from wall behind them is more than adequate.

Is it fair to assume the concrete floors are carpeted ?

If it were me I'd try the following.....

1) Corner bass trapping treatments

2) Seperate speakers by at least another half to whole meter

3) position them back half to 3/4's meter closer to wall, thus allowing your seating position to be not as close to rear wall behind you given the length of your rooom.

4) depending on reflective nature of wall behind speakers you could continue with absorption and or disperssion treatments, along with first relection points if you feel drapes are not enough.

 

[DrJRapp]

. The sound can also be a bit thin with the 50hz setting turned down too much. I think the problem is that I don't have any sound absorbtion on the front wall which is made of high density gyprock. .

My room is about 7 metres long and 5 metres wide with heavy curtains down both sides of the room.
Would appreciate some advice.

You say that the speakers are positioned on concrete. If we assume you mean that the floor is bare concrete then try this. Go to a carpet store and get some samples that they are about to diuscard. These can usually be had for free or close to it. Try to get at least two different densities, medium thick.

Put The Summits on top of the samples. Since one of the Drivers in the Summit is aimed downwards, there will be some frequencies absorbed by the carpet that are being reflected in all directions by the concrete. I'm almost 100% sure (based on my own experimentation) that this will clean up your muddiness.

 

[Neil H]

There were a couple of errors in my previous post. The panel is actually 1.5 not 2.5 metres from front wall. The inside edge of the speakers are 2.2 metres apart rather than 2. The listening position is 3.5 metres from each speaker with 0.8 metres from the back wall.

The room is carpeted with heavy drapes down each side but not at the back or front.

I have experimented a lot with the distance from the front wall and seem to get the best stereo image at 1.5 metres out.

 

[Rich]

If you want cleaner bass, you must install some corner bass traps. It is that simple.

Also, you might try demoing a different amp to make sure that part of the problem is not the synergy (or lack thereof) between your Summits and your current amp. I know it seems strange, but the internal circuitry of the Summits' bass module is sensitive to the signal from the amp. Some amps will produce cleaner bass with the Summits than other amps. I did a direct comparison between an Anthem amp and a Sunfire amp on the Vantages and was blown away at the differences in the quality of the bass reproduction.

 

[JohnA]

I've found heavy drapes to be good if they are behind the panels, behind the listening position (if the couch is very close to a wall) or on the side walls absorbing the first-order reflections (using the walking mirror method)

Carpet is good in general for 'tight' sound and so is a high, non-reflective ceiling.

As Rich said, corner bass traps make a BIG difference.

Of course all this absorbtion means that the amps will have to work harder for the same musical volume - but it will be cleaner.

 

[sleepysurf]

I just bought a GIK Pillar Trap, and one of their new Table Traps, and have noticed moderately improved bass clarity. I also have commercial 2" thickness absorption panels on order to place behind my Summits. Unfortunately, it will be a couple more weeks before I have it all in place for pics.

Check out this thread for further discussion (and stock pics)...
http://www.martinloganowners.com/~tdacquis/forum/showthread.php?t=6467

 

[tonepub]

Im in the GIK club too.

I use a pair of Tri-traps in each corner and the improvement has been incredible!

What you might want to do if you have the time and patience is get your
hands on a sound level meter and a set of test tones going from about 100 hz to 20hz.

You might be surprised where you have bumps and dips in your room!

The Summit makes it easy to dial in with the 25 and 50hz controls....

 

[Craig]

Anyone have a recommendation on a test tone CD? I have the RatShack meter. Also, I believe there was a weakness in one the lower freq ranges of RatShack meter.

 

[benleeys]

Anyone have a recommendation on a test tone CD? I have the RatShack meter. Also, I believe there was a weakness in one the lower freq ranges of RatShack meter.

There's a LF test tone track on the RealTraps site available for free download. Burn it onto a CD and repeat play on your player.

 

[JohnA]

..Also, I believe there was a weakness in one the lower freq ranges of RatShack meter.

The analog version needed some db compensation at lower frequencies.
I've got the table somewhere, I think it was a sliding scale of +1 to +5 db from 100Hz down to 20, or something like that.

I have found no definitive data on whether the digital version also needs the compensation though.

 

[Ethan Winer]

Here's the link:

Test Tone CD

 

[SteveInNC]

I don't know what sub(s) you're running, but you might try adjusting the phase setting on them. When I originally set up my Depths with my Ascent i, I found that changing the sub phase tightened them up considerably. I think I ran them at 90 degrees. This is probably greatly influenced by your particular room acoustics too.

My setup is different now with Audyssey compensation, and the subs are positioned slightly differently, so I run them at 0 degrees.

 

[sleepysurf]

One further thing I'd recommend (even before adding acoustic treatments) is ADJUSTING your tilt angle on the Summits towards a more VERTICAL stance, by elevating the rear woofer box. That will significantly alter the overall tonal balance, including the bass. Initially, just place a thick book under the rear spikes, and see if you like the effect. A number of us Summit owners found this tweak very beneficial, and club member JTWRace manufactured extra long spikes for us. Unfortunately, I don't know if he still has any available, but if not, you could always just use a block of wood. See this thread...
http://www.martinloganowners.com/forum/showthread.php?t=3488

 

[Neil H]

One further thing I'd recommend (even before adding acoustic treatments) is ADJUSTING your tilt angle on the Summits towards a more VERTICAL stance, by elevating the rear woofer box. That will significantly alter the overall tonal balance, including the bass. Initially, just place a thick book under the rear spikes, and see if you like the effect. A number of us Summit owners found this tweak very beneficial, and club member JTWRace manufactured extra long spikes for us. Unfortunately, I don't know if he still has any available, but if not, you could always just use a block of wood. See this thread...
http://www.martinloganowners.com/forum/showthread.php?t=3488

I do have the JTWRace spikes and like the sound tilted forward. I tried an experiment last night and placed a chair on the wall about 1.5 metres behind each speaker and stacked 2 thick lounge cushions on each, with one above the other. What I heard made me think that what I am hearing with the bass turned up is not muddy bass but a glaring of sound at higher frequencies.

With the cushions in place all of the glare was gone. I am thinking now that the turned up bass is somehow causing a resonance which is smearing those frequencies in which the male voice is prominent. Having the cushions in place seems to just tidy things up. I'm now not sure if I need bass traps or some other form of absobtion that cleans up more than just the bass.

Would be interested in any theories as to what is happening in my room.

 

[Rich]

Would be interested in any theories as to what is happening in my room.

In my opinion, you are getting reflections from the rear wave of your speaker which are causing your highs to sound glaring and are probably also muddying your mid-bass response, imaging, and soundstaging. You are also dealing with bass peaks and nulls and the excitation of certain room modes, which are common problems to all rooms and which affects the clarity and quality of your bass response.

You need, in my opinion, a full-frequency absorptive panel behind each speaker, as well as bass traps in as many of the room corners as you can fit. You also need some absorption at the first reflection points on the side walls. If you do this, you will experience a quantum leap in your overall sound quality, clarity, imaging, soundstaging, and bass response. You will get a better bang-for-the-buck upgrade than just about any other component of your system that you could upgrade.

 

[benleeys]

In my opinion, you are getting reflections from the rear wave of your speaker which are causing your highs to sound glaring and are probably also muddying your mid-bass response, imaging, and soundstaging. You are also dealing with bass peaks and nulls and the excitation of certain room modes, which are common problems to all rooms and which affects the clarity and quality of your bass response.

You need, in my opinion, a full-frequency absorptive panel behind each speaker, as well as bass traps in as many of the room corners as you can fit. You also need some absorption at the first reflection points on the side walls. If you do this, you will experience a quantum leap in your overall sound quality, clarity, imaging, soundstaging, and bass response. You will get a better bang-for-the-buck upgrade than just about any other component of your system that you could upgrade.

I fully agree with what Rich is saying. With full range traps behind my Summits as well as first reflection points, bass traps at ceiling/wall and wall/wall corners and diffusers along the rear wall, I have experienced a quantum leap in bass control and image improvements never imagined possible previously. Best value for the $7k I've ever spent on my 23'x15'x8' room.

And Neil, you might wish to take note that raising the tilt angle of the Summits too much may introduced a certain amount of glare in the high freq. which I also experienced. The trick is to try various amounts of tilt till you are comfortable with the sound.

Finally, to add icing on my cake, I also use the Anthem room correction feature in my system.

 

[tonyc]

I perceived my Summits as too bright when I tilted them forward. I ended up with jtwrace's spikes on Black Diamond Racing pucks using the stock rake angle. I use ASC tube traps in the front corners to great effect and someday hope to finish the rest of the recommended ASC treatment. There are lots of less expensive alternatives, but I agree that treating your room leads to big time bang for the buck improvements.

 

[ScottGardner]

In my opinion, you are getting reflections from the rear wave of your speaker which are causing your highs to sound glaring and are probably also muddying your mid-bass response, imaging, and soundstaging. You are also dealing with bass peaks and nulls and the excitation of certain room modes, which are common problems to all rooms and which affects the clarity and quality of your bass response.

You need, in my opinion, a full-frequency absorptive panel behind each speaker, as well as bass traps in as many of the room corners as you can fit. You also need some absorption at the first reflection points on the side walls. If you do this, you will experience a quantum leap in your overall sound quality, clarity, imaging, soundstaging, and bass response. You will get a better bang-for-the-buck upgrade than just about any other component of your system that you could upgrade.

I agree with Rich. For the money this is the best way to go. Here is a link to some good ones:
http://www.audioholics.com/reviews/acoustics/gik-acoustics-244-absorption-panel-review

However having said that; If you want to take to it another level AND if you are willing/able to biamp and/or run a seperate sub AND you can get your hands on an amp that has an extremly high damping factor, Crown K2 for exmple, the bass then becomes very tight. You feel it in your solar plexus. I'm not talking about loud thumping bass, although you can turn it up if you want, I'm talking about really feeling it while not hearing it stand out. (I know a lot of ifs and ANDs but well worth it IMO)