Forte II and First Reflection treatment

[johnsji]

All,

I need your help with setting up my Forte II's in a small, ok really small, room. I haven't had a chance to set my modest system up in years because I wanted to protect it from three (3) little ones. Now I have this dungeon with a lock on the door and am looking for suggestions to help set it up for more critical listening again. []

My scenario:

Room size: 9'5" x 8'10" x 8'

Components:

Forte II - 1990

Adcom GFA-535 Poweramp (any truth to web reports that this type of amp brings out flaws in Forte II's, ex. harshness?)

Adcom GTP-500 Tuner/Preamp

Sony DVP-NS50P/S DVD player (temporary situation) [:$]

Currently the speakers are about 5" from the side wall and 8" from the back. I need to tune this a bit and will probably always be tweaking. Toe-in is a real problem. The more there is, the more the midrange just screams at you. I haven't noticed this as much in the past but I've never had such a small room to work with. I've tried a Music Fidelity Tube Filter between the DVD player and pre-amp without a real noticable difference.

I've looked over the web for DIY designs on room treaments and other articles on where to place them but I'm not sure I can "trust" their placement because they appear to be based on standard, front-firing speakers not one with the horn design. Looking over the Forte literature it would seem that because of the wide pattern of sound the mid and tweater put out, first reflection would be closer to the speaker than the "sliding the mirror on the wall" test or the mathmatical calculations I've found lead you to believe. On top of that I haven't got any toe-in so the side of the speaker nearest the side wall should hit almost immediately...at least in my confused mind. [8-)]

I am on a shoestring budget, one, not two strings, so that is why I'm turning to these forums for help. To improve my listening pleasure I know that I can upgrade absolutely everything, although I really love these speakers, but that is not an option now . I've never tried to "treat" a room but think it is the right starting point before searching for components or cables and such.

Any help you can give me on how to try to get a starting point on these first reflections is appreciated. I understand that this starting point is likely to change over time and comparison listening. Once I've got these down I want to work with bass trapping and then start looking at upgrading components and cables to really enjoy listening to music again. Then I need to get the kids off to college so I can get my bigger room back!

Thanks

JJ

[dragonfyr]

The simplest solution I have is (if at all possible) to place them, toed-in at 45 degrees, in the corner. Many benefits - including the additional spatial loading of the low frequencies.

"Toe-in is a real problem. The more there is, the more the midrange just screams at you."

Let me interpret this! In order for you to hear sufficient LF energy, the highs kill you!

This one is easy! As you toe them in with corner placement, you bring yourself into the on-axis energy of these frequencies!! And they "scream" because the gain you are employing is being used to boost the LF response that is hampered by their being in a space with Q=2 (a hemisphere of 2pi steradians!! By placing them in the corner, the Q is changed to 8!!! With a radiative area of pi/s steradians - 1/8 of a sphere or 1/4 of a hemisphere! A dramatic change!!

This loading effectively means that the LF are particularly effected, as the MF/HF are already subject to a higher controlled Q by means of the horn waveguide! In other words, on axis in your present location, the mids and highs are hot and your bass is NOT!

By placing them in the corner you effectively equalize the system, increasing the LF sensitivity closer to the MF/HF, in fact by a factor of 200%!!! You will have literally doubled the effective radiated LF energy two times! Let me say this again...you have twice doubled the effective LF energy!!!

Then, you can simply turn down the "screaming" MF/HFs and you will have at the same time dramatically increased the bass response! So now you can listen to substantially boosted LF without the MF/HF screaming at you!

Additionally, the corner placement dramatically reduces the near field reflections, with only the floor and ceiling being primary early reflecting surfaces with the horn MF/HF sources.

Thus, you effectively address both problems with the largest ROI on a single "shoestring" budget! In fact, for free!

[sputnik]

As an alternative to the above placement, I'd suggest bringing them in

closer together so that they are maybe five feet apart on centers and

about one foot (or more if you can) from the rear wall and only

slightly toed in. To me, the Fortes sounded better placed away

from walls. I'd be interested to know what placement you think

works better.

[johnsji]

Dragonfyr,

Thank you for your suggestions. It's been a long day already but I will start playing around in the morning. I'll use familiar "test" music from the likes of Camel, Barry White, Alan Parson's, Joe Jackson, some GRP "brand" DDD stuff I have and rock like Green Day, Eddie Money and say Styx to give me some variety.

I may need to employ a test CD and DB meter to help me out but your suggestions give me a path to start from. I'll let you know how it turns out.

Thx,

JJ

[johnsji]

Sputnik,

Thank you for your prompt response also. I've tried moving them closer together and farther from the back wall and wasn't really happy with what I got.

This room is a stickler as it is 3/4 underground with metal studs and standard 5/8 drywall. I don't know how much impact it could have with the room being comprised of two wall types covered with roll insulation and then drywall; half cement and the other half wood.

Another rookie mistake was trying to put treaments into the room without being satisfied with the base sound. I had too many variables cooking at once. Today I pulled all the treatments out and want to get a good starting point.

I'll follow up with you in the next couple weeks as it will probably take me that long to test the first scenario then yours.

Thanks,

JJ

[johnsji]

dragonfyr,

Much improvement with your suggestions. [<)] I probably have some more tweaking to do but in my case it is more like OCD.

The midrange is toned down considerably now. I'm thinking it may be a good idea to measure the sound pressure when I feel they are pronounced, if ever, again. As small as that room is and my proximity to the speakers, I may have the volume up too high anyway damaging my ears...turn it down and all falls in line.

I'll probably be writing a different string before the end of the year asking what would be the next logical step towards improving my sound, ex. cables, patches, components. [8-)] The Klipsch forums have been the most educational and welcoming ones I have ever used; you are a great group of folks. []

Thank you for your well thought out suggestions.

JJ

[PrestonTom]

JJ,

Congratulations on re-viving your Klipsh system!

Dragonfyr has made some good points, think about them. You are absolutely correct in addressing the room issues first. Placement and room treatment (even if it's informal stuff like drapes, carpets & furniture) will have a far greater impact than components (Adcom is nothing to sneeze at) and cables (probably no impact anyway).

The on-axis response is probably the the flatest, so do not worry too much about toeing the cabinets inward. Beside this will also swing the ratio of reveberant vs direct sound back toward the direct path. Depending on the room geometry, try systematically varying the distances from the rear & side walls. Use a CD that is well-recorded and that you are quite familar with. Go ahead and experiment and tweak. It is well worth the effort.

Good Luck,

-Tom