Plywood Quartets

[vnzbd]

I have aquired two sets of Quartets and have disasembled them to do Crites tweeters and cap upgrades and examine the original braceing. My knowledge of these speakers is slim. The product specs show the material as mdf but both sets are plywood. I am assuming that the spec page is wrong, but has anybody seen them made out of mdf?

One difference I found was one set had its woofers installed with wood screws, the second set was intalled with t-nuts and machine screws. I am unsure of the age of either set.

Thanks for any feedback.

[moray james]

sounds like you got a couple of good sets. Here is a ling to a thread with some pictures of some Quartets that were very well braced with plywood braces 2.5" x 3/4" and with pine strapping. I dropped a pair of KLF20 woofers into these re damped them with high density 5/8" fiberglass and then re tuned the passives by adding additional weight. Resulted in superb tight controlled articulate bass well into the twenties.good luck with your Quartet speakers they are excellent and will reward you well for any and all upgrade work that you may do on them. Best regards Moray James

http://www.audiokarma.org/forums/showthread.php?t=372783&highlight=klf20

[vnzbd]

Moray, thanks for the link. Looks like a lot of thought went into your upgrade. I am starting with just caps and ti diaphrams on the tweets. Some internal bracing will be done at the same time. I plan to brace front to sides, back to sides and t&b to sides with braces cut at 45 degrees.

Did you do any crossover mods, specifically the woofer inductor? I would like to learn more about the air core vs. iron core. The North Creek seems very expensive, I just have trouble believing they make that kind of impact.

Thanks

[moray james]

Your idea for using 45 degree braces is a good one that had been my original idea but I did not feel like fudging the peices as I figured not much woulf really be 45 anyway (probably less of an issue than I thought). I would use a bunch of stringer made of 1x1 to tie the front and back right at the woofer and passive. These can also be tied directly to side toside stringers as well. They take up very littl space and more importantly they are very easy to install. The long braces I used were very time consuming to install with glur and heavy weights. Worked very well but very very slow. You might wanr to actually removethe trar baffle to make the job easier then you can get a nailer in there.

If you use an inductor with iron core you will have Hystersis distortion which is the real problem then you also need to be concerned with saturating the cores. I hear what you are saying and I understand that you don't want to believe because of the price but yes the big bad inductors are the way to go. SET12 of this forum has a great thread and you can follow his work. the inductor will have a greater impact than the capacitor. Everyone will tell you no but I believe they are wrong. The cost is high yes but the speakers are worth it and you will not regret the cost. I would suggest that you consider a speaker which is friendlier to such and up grade and which is also a better speaker to modify than a Forte, that would be a KLF 20 which uses a nuch smallet inductor in the bass section dur to the dual woofer VC configuration. It would be well worth your time to read Dan's (set12) thread. Also you can re tune your passive radiators after you have braced and damped the inside of your cabinet. In the Quartets I did I added about 2.5 ounces of weight to the passive and tuned it to 31.5 Hz.The resulting bass response is stunning and very deep the stereo HSU sube are no help now and are not required at all. A Forte re tuned should be exceptional as it pushes much more air than the KLF20 tens I used in the Quartet's. Have fun and use lots of small blocks around the woofer and don't leave out the front baffle cross braces. Best regards Moray James.

http://www.audiokarma.org/forums/showthread.php?t=159340&highlight=crites+autotransformers