Watts [ bi-amping would be a nice choice].

 

thks man..

well thats my issue...

i hesitated on this because from what i read about mlk-165 people say it´s very power hungry lolol so wasnt sure which route should i take, you know... less watt and bi-wiring or more watt-simple wiring, talking SQ here.




greets

 

i'd imagine less power would be wasted through heat biamping.

 

Bridge!!!

 

thks,

now we are square, 1-1 !!

please, more advice people lolol


thks



greets

 

The only thing Bi-amping will give you is separate control over the tweeter level relative to the mid. It's a waste of power.

 

thks man,

i understand that. this is not bi-amping, it´s bi-wiring, if it was bi-amping i would not hesitate, because on the proccess i would not loose any power to the individual channels, much like it is presently (4x75rms). I guess the ml-165 mid included in the kit is more power hungry (150rms-300)than the hcx-coases (100rms-200), and prob you´re right, in terms of raw power in fact the ml-165 would come better with 220 rms bridged.

sorry for the nooby questions, i know you are deep many years into this business.

 

Can you go full active between the HU and the amp? Thus gaining power because your not losing it to the inefficiency of a passive xover. Plus you have move control over xover and tweeter attenuation vs passive.

But with your amp, its bridge power is over triple the single power (most amps are double), going bridge will more than make up for any losses. Plus some xovers have zobels, etc to tailor the sound for the specific speakers that you would lose going active.

 

i could.. the 9887r has a switch to go 3 way active, and still keeps the imprint capability (auto-staging/eq/crossover), but i would only be using to top and mid outs for the active setup.. the low out would be active too, no way to switch active/passive rca outs individually. I this case what would happen to the sub receiving active from the HU? prob i guess just the same as i have now, like crossing at 80hz regardless of the sub amp, isnt it.?



greets

 

If you're using separate amplifier channels for the mid and for the tweeter, then you're bi-ampng. If you're using the Imprint, definitely bridge. At high frequencies, the level and frequency response is MUCH more important than time alignment and the Impring EQ will take care of nearly everything.

 

ok andy, thks a lot, preety clear now. So i guess the hertz mlk-176 will behave better with additional power, it´s rated at 150rms-300, traded for the lower power/bi-amping.

 

Since you are looking for SQ, I vote you run each component off one amplifier channel. Bridging trades SQ for SPL, you get more power but with higher distortion.

With biamping your mids should see more than 75 watts from the amp. The tweeters will draw so little current, the power supply in the amp will be free to power the mid channels.

Dan

 

Since you are looking for SQ, I vote you run each component off one amplifier channel. Bridging trades SQ for SPL, you get more power but with higher distortion.

Not really. The distortion increase due to bridging is typically negligible. Especially in comparison to the distortion introduced by clipping, which is going to be much more frequent if you don't bridge.

With biamping your mids should see more than 75 watts from the amp. The tweeters will draw so little current, the power supply in the amp will be free to power the mid channels.

But the power available to the mids will still be less than if he bridged.

As Andy said, the only advantage gained by biamping in this case is level control and, potentially, signal processing someday if he decides to do so.

 

Don't those JL amps do some weird switching based on load though?

 

I think thats only the slash series which monitors excess rail voltage and latches down to maintain stability at a lower load. In which they start off at the highest rail voltage possible at startup. This would be the opposite of that.

 

also found this



http://sound.westhost.com/bi-amp.htm


which seems quit good learning reading.

 

also found this



http://sound.westhost.com/bi-amp.htm


which seems quit good learning reading.

Yeah, that's a terrific link.

 

sorry for one more nooby question guys, but


adding to that, on an active setup should the control be given full to the alpine head unit, thus disconecting all the filters from the external amp, or is it that a full active setup has no external amp/amp crossovers, coming all just from the head unit.?



greets

 

An "active" setup is basically shorthand for using active crossovers. So you're still running active even if the processing is built in to the amplifier. Sometimes the head unit processing is better to use simply because you can adjust it from the listening location. Other than that, there's no real reason to choose one over the other, unless one has useful features that the other doesn't have.

 

....

 

But when you refer to the amp clipping "harder", what does that have to do exactly with the problem they've stated and their advertised fix for it? In fact, by running their amplifier in class A/B, which they're touting, then it seems to me that they may even be amplifying (pardon the pun) the differences in output devices through gm doubling.

 

I wasn't particularly referring to JL's amps in that post, but rather the decisions made in switching amplifier topologies. But I'll give my opinion on JL's mindset behind it (because I'm curious too )

I'm sure when they say "matching" transistors I'm sure they simply mean the same type of N-channel MOSFET, as creating two that are exactly alike is basically impossible. Most A/B amplifiers use a N-channel MOSFET on the positive side and a P-channel mosfet on the negative, which is the typical "complimentary" or "push-pull" design. The main hindrance in this is that P channel MOSFETs operate more slowly and are more resistant (more heat output with a given level of power), and due to this the engineer has to compensate for this in the design, which is inevitably difficult if not impossible to fully pull off, and because the P-channel MOSFET is the weak link in the chain, it tends to saturate more quickly than the N-channel. So, that results in asymmetrical clipping (the negative wave being clipped moreso than the positive). If you use two N-channels of the same type, inverting one to match with whatever patented circuitry they use (haven't delved into that enough to know exactly how it works), you match the level of power both are effectively capable of producing, and you match the saturation characteristics, which means you've greatly reduced at least one source of distortion.

I don't see where this design really affects crossover distortion for better or worse, I think it's really more about taking advantage of the better N-channel MOSFET in regards to having a matching design that doesn't require circuitry to compensate for the other being slower and less rugged in terms of power handling, in other words taking advantage of matching saturation characteristics. Note that in JL's marketing they don't mention any advantages in terms of reducing crossover distortion, and I HIGHLY doubt they would have forgotten to mention it as they tend to be detail freaks when it comes to promoting the product (ever seen the W7 white paper? )

The remedies for crossover distortion are still going to be forward biasing and negative feedback I imagine, and I couldn't tell you exactly what they did in that regard. As far as an engineering decision, even considering the circuitry, they still have the ability to do as they please in terms of negative feedback just as they would any other amplifier topology, so no clear answer there.

 

Insightful post. Thanks.