Bi Amp

[Ben Lawrance]

Hi All,

 

I've got a pair of Peavey Hisys 5XT's in stock, that I send out on disco's. I want to bi-amp the cabs, but I am unsure as to what to send them.

 

I've looked at the manual, but it only tells me how to put it into bi-amp mode.

 

The cab is 350w RMS with a 15", 6.5" and Compression Driver. The 6.5" and Compression driver run together off the internal x-over, so I know it will be a 2-way box.

 

They are run on top of subs crossed at 150Hz.

 

What I want to know is how much power to send the low, what frequency to x-over at, and how much power to send to the hi.

 

Usually, google is my best friend, but nothing shows up.

 

Any one got any ideas?

 

Cheers

[james jag]

with a 2 way cab that is 350wrms I dont see a lot of point of going through this process to bi-amp it it will give a any audible change in the quality, and you would be spending more money on a second amp and crossovers, save the money and get a bigger pair of cabs.

 

But if you want to covert them then, look at the frequency range, now the power in put to the cab is over this whole frequency range, so if the hf driver is handling 30% of the frequency range then it is also handling 30% of the power in to this cab. :wacko:

[Chris Hinds]

Ben,

 

Scanning the manual on Peavey's website it seems to suggest the crossover point should be 2kHz. That crossover point suggests that it's the 15 + 6.5 that are passively crossed together not the 6.5 and horn. 2kHz is way too high for a 15 to be working which suggests to the alternate. The 6.5 would handle 800-2kHz fine.

 

As for how much power?

 

Peavey's faithful 22XT compression driver is a 40w RMS unit, albeit with fairly horrendous frequency response. The 6.5" driver I wouldn't like to guess as but remove it as the rating should be on the back. Then work from these. Based on the overal Cab rating it's probably about 70W.

 

Hope that's of some use. Be warned you may find it a lot of work for little return

 

Regards

 

Chris

[Simon Lewis]

Ben,

 

why not call Peavey? (which is what the manual states). It also suggests using their active crossover unit, but I'm sure they'll have settings for other devices.

 

However, will a biamped cab be more vulnerable in the hire market you work in?

 

Simon

[Ben Lawrance]

Hi,

 

You are probably correct in saying the cab will be more vunerable, but they only go out with one of my guys.

 

I have other "cheaper" speakers I send out to Joe Bloggs (good ol' behringer)

 

As I'm not really in the financial posistion at the moment to buy new cabs, I have to make do with what I have, therefore trying to maximise their use.

 

James said earlier about buying more amps and crossovers. I already have them (just not sure which amp to use for the tops)

 

Cheers

 

Ben

[Solstace]

Given how much more sensitive horns and/or compression drivers tend to be when compared to their "cone" siblings, I'd suggest you'd rarely want much more than 100W of amplifier for an HF driver, assuming the use of active crossovers.

 

For the bottom end drivers in your rig - I think somewhere around 500W would be a fairly sensible amp rating.

 

Advantages:

 

Should increase efficiency - crossovers do sap some power that you might prefer to go to the relevant drivers.

Should increase fidelity - combined with active crossovers, this setup should go some way to preventing bass frequencies sapping power available to the HF drivers...

Should increase headroom - a combination of the above factors

Allows you to further tailor the sound of your speakers - a little rudimentory perhaps - but sometimes useful.

 

Disadvantages:

 

Liable to over-power the drivers for longer, without the same audible warnings.

Open to errors in setup

Expensive

Consumes more power - something to think about if you're limited to 13A feeds for noise (You've not mentioned this, but many face this limitation)

Gains are limited for expenditure

 

 

In summary - My only question is one of diminishing returns? Is it really worth it for relatively slight gains? Personally I'd save the money and perhaps use it for spare drivers if being mean really causes problems!

 

c.

[Rob_Beech]

are all th independant drivers 8ohms?

 

it may be something to consider.

 

the 6.5 and 1inch conmbination in myW8's which run passive at the moment are 16ohms as a set. you can often find you need rather big amps to power HF sets.

mine run off a QSCplx3402.

 

Rob

[Ben Lawrance]

I've just learnt that their not 22XT comps in the Hisys 5XT, they are HT94's.

 

Just spent a good hour on google trying to find some detail on them, and all I could find was the frequency response of 5KHz-20KHz.

 

Does anybody know how much power these take?

 

Cheers

Ben

[Chris Hinds]

I've just learnt that their not 22XT comps in the Hisys 5XT, they are HT94's.

 

Just spent a good hour on google trying to find some detail on them, and all I could find was the frequency response of 5KHz-20KHz.

 

Does anybody know how much power these take?

Not a clue how much power they would take but in the 5-20k region you won't need much at all. Those two octaves don't contain too much energy. I'd hit them with a 100W amp with limiting set up. On the other hand that frequency response suggests that maybe they are running the 15 up to 2kHz then shoving it into the 6.5" driver, otherwise you'd be left with a big response hole. It's odd there are no specs available, maybe contact Peavey directly and ask?

 

Regards

 

Chris

[paulears]

Although a couple of years ago now, we had a similar peavey set up used in the music department for thrashing. The HND sound people tried what you are suggesting, using a bi-amp rack with Big 'B' electronic x-over.

 

What they found was that they got a lot more control - they could adjust the crossover frequency, and adjust balance - but it still sounded the same as it did with the passive crossover. There was a feeling that a bit more bottom end was available without the HF breaking up - but nobody could actuall put their fingers on it. In the end, the conclusion was that it simply wasn't worth the bother.