The latest round of mischievous programs has been in my mailbox about 100 times a day too. Seems like it was worst about a week ago, and then again two days later. I went to the websites of Computer Associates, McAfee and a couple of other sites that specialized in this sort of thing, and found that they were distributing free updates. I guess they didn't want anyone thinking they were responsible for the errant program in order to increase sales, so they gave the fix away for free. Pretty clever - I wonder how many people purchased their software anyway.

Bill is always making new good stuff, isn't he? What compression driver did you use? Are you talking about BMS?

Nice to see your back online! We got bombarded with that crap at work but the firewall and virus software held it off. The IT guy was steppin and fetchen though.

I'm glad your liking the horns. switch them around in different combinations. I dont know that any one combination of a horn and driver is "the best" for every song you play and through my experience I find the more revealing, defined and detailed your system gets. The more some songs sound better and some sound worse! sometimes I just dont get it.

On the BMS drivers. They are going to be much hotter. I run active crossovers so I can switch stuff in and out in a flash and adjust the gain accordingly. You basically have two small increases to deal with. First off, the wood horn will be giving you a db or two more than some other horns. Second the BMS is a hotter driver than Eminence, JBL, Altec. The Altec drivers I've tested with an FFT analyzer roll off a whole lot more than some other drivers. The BMS drivers don't roll off as much as JBL, and Eminence either.

I dont have an exact number for you, but best guess is another 4db of padding as a start point. You might like to try no bypass cap too. The ones I sent you still roll off. Not like the Neodymium models or even a ribbon tweeter which really stay flat. I think the drivers are very smooth once you get them dialed in. I like them as much as TAD's Ive heard. I dont think the JBL drivers I was using in my home system even compares, and I chose the JBL drivers over Altec, Eminence, and Selenium.

Lots of guys LOVE their Altecs, JBL's and a number of other drivers. Thats what makes this such a great country eh? we can choose!

Bill

well my pc at home runs win95 so it was safe-never had a virus in its 8year life>somehow

:')

Another attractive option is a hardware firewall, which does not have an operating system. Some are relatively inexpensive and the only software running on 'em is firmware so they're pretty robust.

Just rearrange the circuit a bit, having series attenuation resistance before a Zobel placed in shunt across the tweeter. You can play with the Zobel values of R and C to generate the top-octave response curve that you want, and can play with the ratio of Zobel resistance to attenuation resistance to set the amount of damping, which will modify the response near the crossover frequency.

I designed the π crossover specifically to provide rising response. The intended use was with compression horns that had a characteristic negative slope in their response curves, and the π crossover configuration addresses that. Since the tweeter isn't flat, the circuit compensates so that the system is flat. It provides attenuation for level matching, top-octave compensation for the tweeter's inherent rolloff and damping of the voice-coil/crossover interaction so that it doesn't peak near the crossover frequency. But if your tweeter is already hot in the top octave, then this is not what you want.

If you want the crossover to give flat response - or less of a rising response - then a different attenuation and damping mechanism may be in order. Any time there is series resistance, this will introduce some positive slope because the voice-coil is partually inductive. Since the load is inductive, a series resistance will generate rising response. Putting shunt resistance across the tweeter will tend to reduce the slope and make the circuit have less rising response, and adding some shunt capacitance can bring slope to zero, making the circuit flat. That's what a Zobel does. Or the design can go the other way, having series bypass capacitance across the attenuation resistor to increase rising response, like the π circuit does, to compensate for top-octave rolloff of compression horn devices. So using less than a half dozen components in various configurations, you can provide a wide variety of response curves.

The point I'm making is that if you've padded a compression tweeter, then you've added some amount of rising response. You can increase it with configurations like the π crossover using bypass capacitance across the series attenuation resistor. But if you don't want rising response, then the shunt leg should have series capacitance to act as a Zobel. Adding pure resistance in shunt will reduce rising response to some degree, and it will serve to damp the circuit too. But adding a Zobel damper will bring the top octave down to match midband response, and you can completely eliminate any rising response with it too.

I think you'll find that the cable assemblies without top-octave augmentation sound best on things like ribbon and dome tweeters, and from what you and Martinelli are saying, this may also be the case for the BMS tweeters. The π cable assemblies will sound best for Eminence, Altec and JBL compression drivers on CD horns. And something in between sounds best on Altec sectional horns - Something like a π cable assembly with C1 reduced or removed.

I think this may be what you'll find with the BMS drivers too. It will probably be something in between the flat response provided by a straight padded cable and the rising response provided by the π cable assembly. There are any number of suitable networks that will provide response in between these two, so that's where tools like Spice become useful.

I'm going to try your suggestion of the flat cable too. I forgot all about using a zobel on the tweeter. I like to use a small amount (6 or 8db) of passive attenuation on the tweeter with my active crossover. If I use just the active crossover I find the sound much more uncompressed but even adjusting the gain down 10-14db or what ever it takes. I still hear an anoying hiss from the tweeter. This is not noticable on louder listening sessions. For the lulls in classical or a movie, It becomes noticable and it bothers me.

Could you recommend specs for a something around a 5db attenuation using the zobel?

Thanks,

Bill