You're ok with the questions, how else are you gonna find out. I use the Stereophile Test Disc 3. It has High/Mid/Lows. Make sure that you obtain the correction values for that meter. I wish I could tell you where I got 'em, but I forgot. Just google it. First thing to do is set a reference level. I did this by playing the 1khz tone on the disc. I settled on around 70dB to avoid any hearing or speker damage. Then just go through the tones and make a chart (of course adding the correction values) I charted mine on Exel to make it easier. Plus I could make graphs. Hope this helps. Good Luck.
Your not an idiot, but if not already, you may be overwhemed by the task you propose to undertake. Some of us have been lucky enuf to have heard good stuff in an ideal room, properly tuned and set up. That gives us a great basis to evaluate our systems capabilities and possible limitations in our own rooms.
I looked at your system photos. Do you sense you have a problem that you need to solve or are you interested in tweaking your system?
From a two channel point of view your system doesn't 'appear' to be optimally set up. Obviously I've no info on your room size nor the amount of flexibility that you have, nor am I clear if your trying to dial in just the two channel audio or if your are trying to dial in multi channel HT. The following observations are just based on typical results I would expect - I have not actually heard your speakers in your room. I'm just guessing that these could be some problem you may have encountered.
I would suspect that you might have a bloated bass from the proximity of your speakers to the rear wall. I would also suspect that the back wave from the speakers should strike a more dispursive surface - yours looks too flat and too close. Probably makes your highs sound elevated and 'flat', no real sense of depth in the image. Your speakers appear off center in the room and could cause an imbalance due to different side wall reflection arrival times, and the toe in of your speakers appear different. The location of your listening chair is not evident so I can't comment on its placement.
Now to the SPL meter and a test disc. Stereophile has a series of test discs with low frequency (only)1/3d octave tones from 200hz to 20hz, and full spectrum. I like these as the tone is pink noise and steady. Other disc's I heard have not been pink noise and the tone is not steady making it difficult to calibrate. The lowest bass capabilities of the SPL meter are rolled off and you need to apply correction. (The table has been printed many times on this site).
Then using a standard program model for initial speaker and listener position selection (see the Cara program on Rives' site) you start measuring the frequency response. You will need some graph paper so you can record the results at each frequency. Your goal in the bass is to move the speakers and listening position about until you get as flat a frequency response in the bass as possible. Once you have done that you focus on the mids and highs, moving the speakers and listening position about minimally until you produce a sound that is very smooth. Correct toe is a critical issue for smoothness and resolution. If you have done your job perfectly you should not feel like the sound behind the plane of your speakers has any barrier to the sense of depth (i.e. no rear wall). Unless you have an apparent spike in the upper frequencies you feel you want/need to identify with the SPL meter I would suggest you just use your ear for the mid's and high's.
Hope that helps you get started.
Thanks guys, my speakers are pulled out now, they were not in the picture, the panels are 36 inches from back wall, the system is center in room, even if it does not appear so...my room is 13.6 X 19 on the right side wall it opens up to the dining room at about 14 feet back form system wall, on the left wall there is a medium size window centered in room, and on back wall a standard window in center behind couch. There is a small sofa under the window on the side wall aswell. I am just unsure of what to do with the numbers in hand once I have them, if it I get spikes in the highs that would mean I need to absorb some reflections correct? and if I get highs in the low frequency I need to trap some corners perhaps or no?
Ok well thanks a bunch again, and to answer newbie, I am simply trying to check and tweak if needed I dont hear anything alarming, just not sure if I am used to hearing flawed sound if that makes sense. I know my gear isnt the best or anything but I simply want to get the best out of it....cheers
Rives audio sells a test disc which has tracks that are corrected for the Radio Shack meter error. If you use the RS meter, this is the disc to use.
Chadnliz, in response to 'what do I do' with a reading. I assume that you mean that once you have moved your speakers and listening position about and have smoothed out the frequency response as much as possible by doing so, then you should consider how to smooth it out further. Bass is tough to deal with and treatments are frequency dependent so you need to chart the exact frequency you have problems with and then ask for specific advise. Highs typically can be smoothed out by treating reflection points. You can use furnishings or you can get professional treatments, I prefer the former. Keeps it looking like a real room. But, be warned. This is a slow and evolving process. It can take weeks or months of moving and listening before you dial in the optimum set up.
Eldartford, I don't know if you have actually listed to the Rives disc but when I used it in my system I found many of the individual test tones were not steady and because of that were difficult to track. Not so with the Stereophile disc. Is that problem unique to me? What did you experience?
Newbee...Yes I used the Rives disc, but only briefly because I got myself a spectrum analyer that is much easier to use. I don't recall the problem you mention, but I will put the disc on again and look for it. I will also look (with the analyser) at the electrical signal to see if it is stable. What I did notice is that with the higher frequencies quite small movement of the mic causes large SPL variation. You can also hear this when you move your head around.
Thanks again, I will report results and see how to make use of them, and I did find Sean's correction chart....will keep in touch..cheers all!
Eldartford, I think what you described could well be what I experienced. I was hand holding the meter.
Just some random related thoughts... I am in the process of tuning a listening room I put together, and the speakers are Quad 988's. With the radio shack meter, the frequency response is all over the board. A friend is sending me a spectrum analyzer. Has anyone compared a spectrum analyzer vs. the RS meter? If so, I'd be interested in any findings.
Also, I am looking for some advice. I believe I can set up a spectrum analyzer with my laptop. I've got an Edirol A/D converter that takes a microphone input, and outputs to USB. I've got a computer program that shows the spectrum on it. I think all I need is a decent microphone that has either a flat response or a response I can compensate for with my computer program. Anyone have any suggestions for such a microphone - something fairly flat but not too expensived?
My room is similar in that one side opens to another room. I have found that I can almost balance this out by using absorption on the wall opposite to this opening. I can do whatever I like since my room is a dedicated finished basement. You may have to get creative with window coverings or something in order to kill the reflections from that near wall. Based on what I've experienced with balancing an unbalanced setup in this way, it will be well worth your efforts.
BTW, another good place to find out about this stuff is over on AA in the Rives forum.
Peter_s, I fdund this while browsing around.
Peter_s...The Behringer mic is the one I use with my Behringer DEQ2496, and it is a good item..BUT...it requires a "phantom" power supply from the unit it is plugged in to. I don't think your computer does this.
You can download and burn this test cd...it's free. Make sure you read the info. first as it is a bass test cd only.http://www.realtraps.com/test-cd.htm
Thanks all for your help!
I have been considering using Rives Audio to help me with my room. Are they the best available group ? Any comments on those who have used Rives ? They seem like great people.
Rives is very generous with free advice for the DIY guy, and I would take this attitude into account when hiring professional help. And furthermore, what they say seems to make good technical sense to me.
I'd put my money on them if your residence is going to be somewhat permanant. I tend to move a lot (i rent), so I bought the CARA software and can do the best I can on my own.
Larry (Cello), I had the level one service performed by Rives on my room and they were a pleasure to work with. I followed their final recommendations regarding treatments, locations of same, and equipment placement. The equipment placement was a 180 degree change from where it was before we started.
End result: Most effective cost/benefit upgrade I have ever done. Room aesthetic is pleasing, acoustic is wonderful, and my music has never sounded better, not only to my ears but to those ears of some fellow AudiogoNers whose knowledge and hearing I respect.
Rives is highly recommended. Richard Bird is very easy to get a hold of, listens to what you are telling him, and is VERY generous with advice.
Slipknot1 - when it came to acoustical treatments, did you have them recommend particular products or did they supply you information/assembly drawings that you could make or install yourself?
From the photos of your system, I can see a number of wall panels and some corner treatments. Could you provide a little more information on what you did in terms of materials and what Rives supplied?
I'm working on the acoustics in my room and have been doing a lot of reading and playing with some DIY treatments. The Rives site is a great starting point and I may eventually have them take a look at my room as well.
Before you start spending megabucks on all kinds of test equiptment, walk around your room as is, no music playing at all and CLAP very loud, as loud as you can. The area that sound reflects best back to you is an area for treatment. If you have hardwood floors, ask a ladyfriend to walk aroung with heels and listen for the reflections off the shoes. Best Advice, Call Mike Kotchman of eco busters, he will be willing to help you.
Sorry for the delay in response. I have not been posting too much lately. Too many other things going on.
To answer your question. Every treatment, right down to the rug on the floor is there per the "Rives plan". The corner treatments are RPG Variscreens. They are very expensive, but very effective hinged screens that are reversible. One side is diffusion, one side is absorbtion.
The ceiling treatments are from Quest Acoustical Interiors, as are the wall treatments. The fabric covering them is from Guilford Of Maine, acoustically transparent and available in a host of colors. You order the panels from Quest in the color you want and they arrive ready to hang. Both RPG and Quest give Rives clients a discount. Depending on the amount and type of treatment Richard recommends a lot of it can be DIY. Richard will give you lots of great advice if you want to go that route as well.
Rives gave me basic dimensions and materials type for the floor rug and I took it from there. The room had an artificial fiber wall-to-wall with hardwood under it. The plan called for pulling it up and replacing it with a 100% wool area rug. I purchased a Persian carpet through a rug broker. I ordered everything directly from RPG and Quest and installed themself based on placement as laid out in the final room plans from Rives. All the window treatments and the doors were done based on their recommendations as well.