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Want to make Quartet or Forte into center channel.


Robert Gervais

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Since the Forte' II uses a larger Tractix horn I think it would sound good laying on its side with no modifications. I use a La Scala laying on its side sitting under my Sony RPTV and it works very well - seamless front stage with the Khorns. If you find the sound is not acceptable (not very likely) the mods to the motor board you described would work as well. You can remove the riser base just for aesthetic reasons.

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Robert - You may find that the Forte midrange horn will hit the back of the passive radiator if you attempt to reposition the mid/high horns to the center of the motorboard. I found this on my Forte. I reached the conclusion that I probably would have to completely rebuild the cabinet, as both the front and rear boards need to be remade to reposition the passive radiator.

DD

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I think Frzninvt has a good idea and I may give it a try this weekend. In the end, however, it may be best to use Quartet or Forte II drivers, repositioned in the center and surrounded by two 8 or 10 inch woofers. This, espically if room is a problem. Either way, let's compare notes. I think there are seversl prople in this position.

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This is the Quartet that I made into my center.

Quartet3.jpg

I have a couple of sets of Forte IIs for main and surrounds. I have since replace the tweeter with a Forte II tweeter/crossover and the woofer with an Eminence Beta for a couple of extra SPLs. Balanced woofers don't seem to be really necessary when you are crossing at such a low freqency point. I DO have the horns positioned over the middle of the screen, so the speaker is off center a bit. I am more than pleased. I also thought about placing a Forte II on its side on a floor riser under the screen and mounting the horns in a separate cabinet above the screen.

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jerohm,

I also have 2 sets of Forte IIs and one pair of Quartets. This is what I would really like to do. A few questions please.

Did you use the Quartet cabnet and if so was it modified?

What did you do with/about the rear passive woofer?

Can you compare the Quartet center with any one of the Klipsch Centers?

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Jerohm,

That is magnificent.

I have not decided what to do with my four Quartets at the apartment. Right now that thought is that I'll experiment with the equipment I have and eventually buy an HT receiver and a big screen TV and use one as a center. Depending on what TV I buy, the more bunged up Quartet might get converted to something like what you have done.

Horn Ed is a big proponent of full sized center channel speakers. At least bigger than what most sell. There is much merit to it, in my mind.

Gil

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FWIW Laying any smaller horn Tractrix or Exponential on its side will sound good. In some cases it will sound even better. Look at the vertical cornwalls desired so much in the 2 ch area. Trey even told me that the K77 and K600 were designed to run verticle. I have K700's vert and prefer the sound over Horz.

As for the rear passive, do what you would do if they were on the wall. Move the speaker closer and farther from the wall to see where you get the best sound. If you want them to look good and be flush to the front of your cab, you could put a sound board behind the speaker securely fastened to the wall at whatever depth sounds best. Could evan V the boards making a false corner behind the speaker. Lots of possibilites.

Boomac, if you need or want any help, email me. Could give you a hand.

JM

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The design that I finally settled on was based on simplicity to implement. The motor board in Quartets (and Forte IIs anyway) is supported by a channel routed into each side of the cabinet in additional to a ~3/4" square brace around the inside perimeter using glue and staples. Removing the old motor board intact is pretty much out of the question. The cabinet is the Original Quartet Cabinet with the riser removed. I cut out the motor board along the inside edge of the (3/4") bracing. The motor board seemed to be constructed by a glued layering of 1/4" and 1/2" plywood, where the drivers attach to the 1/2" bottom layer, and the 1/4" layer accommodates for their flush mounting (do you understand what I am trying to say??). Because of this, the openings on the front of the motor board are larger than those on the 1/2" bottom layer; it is created from high quality, no void stock. Rather than try to create these rather complex (to me anyway) openings on special stock, I opted to reuse the original motor board. As someone noticed, I cut the woofer mount from the horn section and squared up the pieces. I had a local cabinet maker completely biscuit spline and frame the two pieces with rock maple ($125) to create the new motor board (extremely strong).

The frame acts a cap and attaches to what remained of the original motor board/bracing. The woofer is no longer positioned directly in front of the passive radiator, but it isn't required too! The grill is a friction fit, but I could reinstall the magnets if I needed too.

I have it mounted using a television wall mount (to a stud!!!) and sits about a foot from the wall. The mount allows for positioning adjustments.

I recently replaced most of the Quartet components with Forte II replacements. The Eminence Beta woofer is slightly more efficient than the original Quartet woofer, and the unit seems to compete with the Forte IIs effortlessly (It is too hard for me to say if it is THAT much (ANY?) of an improvement over the original Quartet components).

Over the years, I started out with a KMC (KV-2), then C7, then an unmodified Quartet (upside down on resting on top of the television and later on its side mounted to the wall). I am very satisfied with the results and not think twice about doing it all over again. The full range center may have the most pronounced effect with music (I used DTS:NeO6 almost exclusively now).

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On 10/1/2003 3:47:54 PM Robert Gervais wrote:

I noticed you have the tweeter below the midrange. Any reason for that? How would you rate the sound before the modification and after? Did you replace the internal wiring with upgrade wiring (monster, etc.)?

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The speaker is pretty heavy and putting it up, and taking it down, from the wall mount is still quite a challenge. I 'reasoned' that the highs might be lost a bit being so close to the ceiling. I haven't really experimented to prove of disprove my hypothesis - it sounds great so I don't have any real incentive to change it. As far as the wiring, it is stock Klipsch. Attaching thicker gauge wire to the crossover is certainly doable, but I didn't really feel the need. I made a small modification to the Forte II low pass LC values to accommodate the Eminence woofer - but it was done by brute force using a sweep signal and my ears. I WISH that I could have control over the vertical position of the wall mount, but that isn't an option. The front three speaker blend seamlessly and pretty much disappear. Is it perfect? - probably not, but I am at the point of diminishing returns. (The cabinet maker is suppose to make the other motor board before Christmas. I will post pictures before I attach it to the other cabinet).

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I might just have to take one of the Quartets and give it a shot! Thanks for all of the help and insight from all of you. I think the Quartets would fit better under my TV than the Forte's. I'll let you know how it turns out. Jerohm could you email me a rough design of what you did? I would appreciate it. Thanks.

RG

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On 10/4/2003 1:41:32 AM SCOOTERDOG wrote:

Heck, I thought I'd throw in my 2 cents on centers. Mine, like Horn Ed's or STL have gone to dual woofers in our centers with the mid and tweet staked.

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Nice!

Aesthetically your design wins hands down. In actuality, most centers are two way designs and cross the drivers at well over 1KHz; the woofers end up reproducing some of the human vocal range - making dual woofers pretty much necessary. For a three way design, you should be fine so long as the horns are centered over the display.

I have contemplated putting the horns in their own cabinet above the screen and keeping the bass as a floor unit beneath. I believe this "may" be a superior solution (and relatively easy to implement).

P.S. Robert: I "tried" to layout my design in previous posts. Exactly what other details are you looking for? If you email me your phone# and a good time to get you, I will give you a call.

jim

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I was also thinking of splitting the mid/high cabinet and low end cabinets for center channel... I have La Scala's as front and rear (both are two piece Industrial/Pro models). In the front I have my La Scala Pro's on top of a pair of 18" Yorkville subs, this leaves my squawker and tweeter at ear height and was too intense when walking by the speakers at high volume. Since the La Scala Pro's I have are two piece I put the top cabinet on 3 - 1 3/8" dowels bolted to the bass bins, the dowels are about 18" in the front and about 20" in the back, they are at about a 5 degree angle down. The mid/highs are even with the top of my projection screen and sound amazing, great dispersion throughout my room which is 17' x 70'. I am looking for another La Scala Pro (or pair) to use for the center (currently using a KP-201 (Heresy Pro) with a Professional 15" sub to create a larger sound). My ideal is to use a two piece La Scala and have the bass bin below the screen and the top mid/high flown above the center of the screen at an angle.

I love seeing all the other full heritage theater systems!

SYSTEM:

B&K AVP3090 pre-amp

BBE 362SW sonic maximizer

JVC XV-SA75GD

Adcom GFA 5503

Adcom GFA 555

Adcom GFA 555 Pro

Adcom ACE 515

Klipsch La Scala Pro (front)

Klipsch La Scala Pro (rear)

Klipsch KP 201 (pro Heresy) with Klipsch KP 115 (15" sub) (center)

Yorkville Elite SW 800 (pair) 18" subs

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