BiAmping some Boston Acoustic Z6 components with a JL 450/4

[caelric 10+ year member]

As the title states, 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

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[alphakenny1 10+ year member]

wait don't you have the crossovers that come with the set? use those and thats it. and then hp on the amp or something so the mids don't see the low low frequencies.

 

[squeak9798 5,000+ posts]

Yeah...bi-amping infers you are still using the passive crossovers that came with the set to split the frequencies between the mid and tweeter. All you should need to do is highpass the mids. And you just highpass them where ever sounds best. Don't use the "rated" frequency response as a means to guesstimate either....just use your ears and your head, and set the highpass crossover for the mids to whatever frequency sounds best.

Or are you trying to run active?

 

[caelric 10+ year member]

No, I am still using the passive crossovers that came with the BA's, but if you set the amp correctly, it won't be trying to reproduce frequencies on channels that don't use them. So, the woofer channels (150x2) would only be reproducing the bandpass freqs, and the tweeter channels would only be reproducing the highpass freqs, thus allowing each seperate channel to concentrate it's rated power on those freqs. Theoretically, this makes the amp run better.

Dave

 

[squeak9798 5,000+ posts]

Theoretically, this makes the amp run better.
Dave

Hogwash.

Plus, doing it your way could actually alter the sound differently than intended, since you would be altering the signal being sent to the passive xover. It could effectively alter the slope of the crossover, and hence alter the response. This is not something you want to have happen.

Don't even bother trying to cross the signal at the amplifier if you are using the passives. Just run the highpass filter for the mids and you're set.

 

[Colin+M 10+ year member]

exactly

 

[thefunkybunch 10+ year member]

Hogwash.
Plus, doing it your way could actually alter the sound differently than intended, since you would be altering the signal being sent to the passive xover. It could effectively alter the slope of the crossover, and hence alter the response. This is not something you want to have happen.

Don't even bother trying to cross the signal at the amplifier if you are using the passives. Just run the highpass filter for the mids and you're set.

agreed.

unless you are going active with the setup (which i've had no luck at all with boston, so i've stayed with the passive xovers) but if you go active, then this is worth a read //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

https://myeporia.eporia.com/resources/company_38/techpaper104.pdf

 

[caelric 10+ year member]

Ok, thanks for the info, everyone.

Dave

 

[madison29 10+ year member]

sorry for the hijack but what is the advantage in biamping a set of comps in passive mode? i know each speaker would have its own power but wouldn't it anyway since the passive crossover doesnt split power if ran off of a 2 channel amp?

(example)

biamping with a 4 channnel amp 75x4. each tweets would get 75 and each woofer would get 75.

a 75x2 amp would still give each tweet 75 and each woofer 75 running through a passive crossover, correct?

sorry i'm not good trying to explain myself!!!

 

[madison29 10+ year member]

bump

 

[FoxPro5 5,000+ posts]

sorry for the hijack but what is the advantage in biamping a set of comps in passive mode?

i know each speaker would have its own power but wouldn't it anyway since the passive crossover doesnt split power if ran off of a 2 channel amp?

(example)

biamping with a 4 channnel amp 75x4. each tweets would get 75 and each woofer would get 75.

a 75x2 amp would still give each tweet 75 and each woofer 75 running through a passive crossover, correct?

Correct.

sorry i'm not good trying to explain myself!!!

We understand you bud //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[dgoodhue 10+ year member]

sorry for the hijack but what is the advantage in biamping a set of comps in passive mode? i know each speaker would have its own power but wouldn't it anyway since the passive crossover doesnt split power if ran off of a 2 channel amp? (example)

biamping with a 4 channnel amp 75x4. each tweets would get 75 and each woofer would get 75.

a 75x2 amp would still give each tweet 75 and each woofer 75 running through a passive crossover, correct?

With the 75 x 2 amp it would be split between the tweeter and woofer for a total of 75 watts for each side. With a 75 x 4 amp essentially each side would be getting 150 watts. I like my Z5's biamped better, because it allow me to fine tune the gains for woofer and tweeter, to my ears it sounds cleaner that way.

 

[madison29 10+ year member]

so what your saying is the tweeter would get 37.5rms and the woofer would also get 37.5rms? i thought passive crossovers don't split power, just frequencies.

 

[FoxPro5 5,000+ posts]

i thought passive crossovers don't split power, just frequencies.

Correct again.

 

[M3NTAL 10+ year member]

Correct again.

So, what is the advantage of bi-amping a passive x-over setup? Only thing I can think of is that the end user has a 4 channel amp that doesn't like being bridged?