boston z series...

[thefunkybunch 10+ year member]

does anyone know approximately what boston crosses their z's over at? playing around with the crossovers i noticed that even dropping the tweet from 1.3k to 1k you can easily hear that it picks up more range... which seems pretty low for a tweet xover frequency to me, but perhaps that has something to do with their nifty AMD stuff... and of course they certainly don't want anyone messing with their stuff and will not release any info whatsoever to someone trying to go active with it because they don't want you to ditch their xover network. was considering going active with it, but i don't want to go out and destroy a $300 set of speakers 'experimenting' to see if i can improve anything, or should i just let it be. they are currently bi-amped through the z passive xovers. i really have no knowledge about how crossovers are built and what parts to what (i know the very basics, but that's about it) is there anyway to tell mathmatically what they're crossed over at by adding up values on inductors and capacitors? or does the signal go through different capacitors say when you change the switch from -2db to 0db, etc or sq1 to sq2. any ideas would be appreciated.

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[thefunkybunch 10+ year member]

anyone?

 

[squeak9798 5,000+ posts]

i really have no knowledge about how crossovers are built and what parts to what (i know the very basics, but that's about it) is there anyway to tell mathmatically what they're crossed over at by adding up values on inductors and capacitors? or does the signal go through different capacitors say when you change the switch from -2db to 0db, etc or sq1 to sq2. any ideas would be appreciated.

Yes, if you open up the passive xover and essentially reverse engineer it you should be able to calculate the xover points.

http://www.the12volt.com/caraudio/cross.asp

 

[OlogyAudio 10+ year member]

Yes, if you open up the passive xover and essentially reverse engineer it you should be able to calculate the xover points.
http://www.the12volt.com/caraudio/cross.asp

I'm pretty sure the Z series doesn't use a textbook xover... I could be wrong though -- but they claim they don't haha... It is starting to get into the price range where they may actually invest some time in the design... or hire someone with some skill...

 

[squeak9798 5,000+ posts]

It's still nothing beyond the realm of physics //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif They engineered it, you can reverse engineer it.

 

[JimJ 5,000+ posts]

It's still nothing beyond the realm of physics //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif They engineered it, you can reverse engineer it.

Tell that to Powered4Sound, or Bose...//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif//content.invisioncic.com/y282845/emoticons/up2something.gif.dd110ecf3ae4b76050d87598f2f8de7c.gif

 

[thefunkybunch 10+ year member]

lol i see very little engineering in anything bose on exception is the subwoofer setup in a rx7... a cool design but i never heard it actually play. the radio was toast when i removed everything and put better stuff in so i didn't get to hear it //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

i don't really intend to take apart my doors again to take apart my crossover and try and figure out the math, they're kind of a pita, but we have a xover on display at the shop that's already opened so i'll have to look a little closer at it.

the tweeter attenuation switch, what effect does that have in the crossover. when you flip it to different settings, does the signal take a different path through the crossover, or how exactly does that work?

same with the sq1 and sq2 switch, supposedly meant for on axis and off axis mounting iirc, not sure if that affects the signal path through different components on the crossover. it definitely is not a small crossover, that's for sure! and the little light bulb thing, they told us that is for protection from overdriving the tweeter, does this play any other part, or is that it?

also the AMD setup they use is supposed to fix some nasty spikes in the tweeter response and make it considerably smoother. without purchasing an audiocontrol eq (which i really don't want to get that far into it, i follow the KISS principle) is there any other way to get around that? i am currently running a 9855 3 way, but will most likely be switching to a clarion 9255 in the next month or so.

or should i just stick with the boston crossover, biamplified like it is now, and call it a day? i know boston says to definitely not lose their crossovers, but don't all manufacturers? just trying to weigh the pro's and cons here //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[OlogyAudio 10+ year member]

It's still nothing beyond the realm of physics //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif They engineered it, you can reverse engineer it.

I can... but not with the info on that webpage thats for sure

As for bose... They spend a ton of money jacking off... oh and marketing -- kinda comical //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I'd say keep the bostons xover... atleast they claim they did a decent job Or try it both ways.... just try not to nuke the tweeter...

 

[thefunkybunch 10+ year member]

I can... but not with the info on that webpage thats for sure

yeah, they REALLY don't want anyone knowing what is going on... i'm sure an engineer could figure it out, but i'm thinking i'll just stick with boston's crossovers. they sound great as it is, just need to fix my source unit problem //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[glennlewis 10+ year member]

I am using older Nakamichi EC200H and EC200 in a system with 5.25 Boston Pro series and I have no trouble setting the crossovers anywhere I want. The H has crossover points of 1.8,2.5,3.5,4.5,6.0 K. I can't imagine going much below 1.8 K for tweeter function due to the harshness of the reproduction in that frequency range.

 

[caelric 10+ year member]

Bumping this to try and get an answer to my question, which is related to your question.

I am bi-amping a set of Boston Acoustic Z6's with a JL Audio 450/4 amp. I have the 150x2 channels going to the woofers and the 75x2 going to the tweeters.

Considering that I have a JL 10w6v2 powered by a JL 500/1 in the trunk for the sub, what crossover settings on the 450/4 should I go with? In other words, what is the bandpass range for the woofer (on the 150x2 channel), and the high pass for the tweeters (on the 75x2) BA's website is not much help, it merely states the frequency response fot he overall system is 40 hz to 22 khz, but doesn't break down the woofers vs the tweeters.

Any suggestons?

Dave

 

[squeak9798 5,000+ posts]

Any suggestons?

Yes......to look at your thread for the replys to your question.

 

[thefunkybunch 10+ year member]

Bumping this to try and get an answer to my question, which is related to your question.
I am bi-amping a set of Boston Acoustic Z6's with a JL Audio 450/4 amp. I have the 150x2 channels going to the woofers and the 75x2 going to the tweeters.

Considering that I have a JL 10w6v2 powered by a JL 500/1 in the trunk for the sub, what crossover settings on the 450/4 should I go with? In other words, what is the bandpass range for the woofer (on the 150x2 channel), and the high pass for the tweeters (on the 75x2) BA's website is not much help, it merely states the frequency response fot he overall system is 40 hz to 22 khz, but doesn't break down the woofers vs the tweeters.

Any suggestons?

Dave

the best results i've found are high passing the mids at about 50hz with a 12db rolloff, and letting the passive xovers do the rest //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[FoxPro5 5,000+ posts]

Hope this helps your quest funky:http://www.soundbuggy.com/Eric/Car%20Audio/random_car_audio_stuff/boston_z6_crossover_response.jpg