Cross-over in specs?

Talon_Sr

No, actually my new receiver is a bit smaller than my last A/B receiver and this is what class D amps can do. Better efficiency mean less cooling fins and smaller space and less weight. This concept is not revolutionary. Consider that the first computers were the size of an entire room. Now you have smaller units that you can hold in one hand or wear on your wrist, store infinitely more information, run faster, run cooler, and compute better. The audio equipment is no different. It will get smaller, run cooler and produce better sound.

FTGV

Talon_Sr wrote: »

And they're bigger than the devices I already have taking up slots.

Not necessarily.For example Hypex http://www.hypex.nl/product/2012-11-23-13-44-01/2012-11-23-13-46-04/as2-100.html and Mini DSP http://www.minidsp.com/products/plate-amplifiers/pwr-ice125 have introduced several plate amp modules with a pair of Class D amp channels with integral DSP.A couple of examples for their use from both ends of the price spectrum.
http://bambergaudio.com/products/series3/3tmw.php
http://www.hifizine.com/2013/09/the-mini-convertible-active-loudspeaker-design/

Cost and complexity have kept fully active systems from the audio mainstream but neither are an issue for DIY ers.Witness the popularity of Linkwitz Orion and LX521 designs.Both have the option of using a fully optimized analog or digital active crossover.

I personally have been rolling my own active speakers and crossovers for the last 1/2 dozen years or so.I'm currently using a combination of Hypex Class D and Bryston for amplification.
I have tried a popular inexpensive DSP crossover/EQ but find a well built opamp based analog unit to outperform it the by a wide margin.It's more of a matter of the inexpensive nature of the digital unit than the concept.While it is extremely versatile,it allows considerable control over the customization of the response,but inferior A-D D-A processor IC,s,power supply scheme etc. limit it's potential.IMO a DSP crossover/EQ component needs to have the same attention paid in regard to the design of it's processor chips,power supply and analog output stages as a high quality 2 ch DAC.Of course that won't come cheap.Think DEQX.

FTGV

Some interesting commercial active designs from the recent past that I have admired,atleast in design concept since I have not heard them..
The NHT was nice in that all 6 ch of amplifcation and DSP crossover are in a single compact chassis.
http://www.stereophile.com/standloudspeakers/1105nht/

http://www.aurumacoustics.com/integris_300B.html

http://www.audiophilia.com/hardware/waveform.htm

Talon_Sr

I still have a Koss 4DS digital delay unit that is as big as a receiver. All it did was provide ambience. Now that unit goes into the vintage audio equipment bin on eBay for sale. I don't need it any more because DSPs are doing the same thing and are integrated. Parametric EQs go by the wayside because it is taken care of by miniature chips in today's receivers. Look at the evolution of photo and video. Who doesn't have a camera that produces better resolution and color reproduction than what was available 15 years ago. Same thing with TVs and video recorders. The purists don't like it because they are losing their bragging rights. You just accept it and move on.

Talon_Sr

FTGV wrote: »

Some interesting commercial active designs from the recent past that I have admired,atleast in design concept since I have not heard them..
The NHT was nice in that all 6 ch of amplifcation and DSP crossover are in a single compact chassis.
http://www.stereophile.com/standloudspeakers/1105nht/

http://www.aurumacoustics.com/integris_300B.html



http://www.audiophilia.com/hardware/waveform.htm

FTGV, that's it! The DEQX is showing that it can be done. Sure it's at least $3K now, but as with all things, the price will come down and it eventually become mainstream.

and it goes on:

"The XdA also includes four PowerPhysics class-D (switching) amplifier modules to biamplify the two XdS speakers. While the general design of class-D amps is well known, the PowerPhysics designs are claimed to offer better fidelity, especially in the higher frequencies, because of a proprietary feedback design that provides output correction on each output cycle, even though the switching is at rates of 250kHz or more. Particular attention was paid to the design of matched switching power supplies, which virtually eliminate overheating at high levels but do not require large heatsinks or fans. "

Which is what I was saying about the class D amps.

FTGV

Yes it's doable but keep in mind the integation here of crossover and amplification is optimized only for this specific speaker.Including generic DSP crossover capabilities(other than for LFE) as part of an HT reciever could be a recipe for disaster as far as SQ is concerned.The crossover be it DSP active ,passive, must be optimizied for the specific drivers of that system.Randomly removing the passive crossover from a good loudspeaker and making it fully active is likely to make it sound inferior to what the orginal designer intended.There is some engineering involved if one wants to properly move from a passive to active crossover.

Talon_Sr

But this unit made re-calculations for mic movement on the fly.

"The DEQX system measured the response of a speaker's individual drivers and synthesized both digital filters to linearize phase response, time alignment, and amplitude response in the frequency band where each performed best, and crossovers operating in the digital domain. By moving the test microphone farther from the speakers, the influence of the room could also be measured, compensated for, and included in the filters. "


So that is a step in the right direction. If the tech is there for a mic to use sonic feedback and determine the characteristics of, let's say ANY speaker, then it is very possible.

FTGV

This link that I posted previously is a good tutorial of what kind of developement steps are necessary with a simple 2 way speaker when using DSP. http://www.hifizine.com/2013/09/the-mini-convertible-active-loudspeaker-design/

FTGV

Talon_Sr wrote: »

.

"The DEQX system measured the response of a speaker's individual drivers and synthesized both digital filters to linearize phase response, time alignment, and amplitude response in the frequency band where each performed best, and crossovers operating in the digital domain. By moving the test microphone farther from the speakers, the influence of the room could also be measured, compensated for, and included in the filters. "


So that is a step in the right direction.

Yes.

F1nut

No, actually my new receiver is a bit smaller than my last A/B receiver and this is what class D amps can do. Better efficiency mean less cooling fins and smaller space and less weight. This concept is not revolutionary.

My SC-37 is about the same W+D, but is definitely taller than my last A/B receiver. I could care less about efficiency, the size of cooling fins, space or weight when it comes to AVR's as none of them are all that when it comes to music.

The purists don't like it because they are losing their bragging rights. You just accept it and move on.

I don't know any purist that would consider an AVR their end game. You need to accept that.

Talon_Sr

I have. And it's not a problem for me.

tonyb

I think what he's eluding to is that receivers sound just as good as separates, hence the bragging rights comment. While receivers have certainly come along way in SQ, separates have also made the same jumps.

His analogies of other things being made smaller is fine....except we don't listen to those things. Me personally, haven't heard every brand of ice amps out there but the ones I have heard don't do it for me.

It's not a matter of pulling out D$CKS to see whose is bigger, though with some it very well may be. More so a discovery of good sound as the primary target. We live in a world of smaller is better, that's what sells anyway, ask Bose. When size and convenience are the top 2 priorities, sound quality becomes a distant 3rd.

Talon_Sr

Yes, it is definitely a balancing act between convenience and "what sounds good to me". The problem with purists, is that they are never happy in their quest for audio nirvana. A lot of my friends tell me I spend too much time "fiddling" with my system. And that it sounds great already. But I tell them it's a hobby and they understand. I upgrade my system maybe once every five years. My first receiver was a circa 1975 Marantz 2252B paired with Pio HPM-100s (which I just sold recently on eBay). I used that receiver for maybe twenty years until I bought a home and decided to make the move to HT. The first AVR was a 5.1 Sherwood, followed by a Pio VSX-1018AH, and now finally a Pio SC-1523. I'm almost 60 now and probably will not upgrade many more times. But I do love the sound of good music. I'm not na

F1nut

You seem confused.

don0

F1nut wrote: »

For starters, it's rated at 135 wpc with 2 channels driven. The more channels driven, the less wpc.

So, let's say it delivers 100 wpc with 7 channels driven and 80 wpc with 9 channels driven when you ghetto bi-amp. You now have 80 watts going to the woofers of your ghetto bi-amped speakers and 80 watts going to the tweeters, of which almost all of that going to the tweeters is wasted. Bottom line, the woofers are likely to get less power by ghetto bi-amping.
.

In the above example, with 7x100 and the tweeter using only five watts, for example, wouldn't that leave 195 watts available for the woofer?
195 + 5=200 watts for the two channels going to the left speaker and the same for the right speaker if each channel is capable of 100 watts each.

That is assuming that the other three channels are center and two surrounds. That would be the seven channels at 100 watts each.

don0

nbrowser wrote: »

Heh automated set up, yeah my Onker has it, the mic has never has been removed from it's box, maybe I can gift it to someone missing an Audyssey mic but I digress. I set my rig up manually with a heavy heavy bias towards 2 channel listening, HT is an afterthought as the other half wanted a full HT system. Sometimes automatic set up is nice but for some, they'd rather do it themselves.

I like mine better with the auto setup off and the tone controls set on 0. Speaker levels and distances were set correct by auto setup.

don0

nbrowser wrote: »

Heh automated set up, yeah my Onker has it, the mic has never has been removed from it's box, maybe I can gift it to someone missing an Audyssey mic but I digress. I set my rig up manually with a heavy heavy bias towards 2 channel listening, HT is an afterthought as the other half wanted a full HT system. Sometimes automatic set up is nice but for some, they'd rather do it themselves.

I like mine better with the auto setup off and the tone controls set on 0. Speaker levels and distances were set correct by auto setup.

Hermitism

don0 wrote: »

I like mine better with the auto setup off and the tone controls set on 0. Speaker levels and distances were set correct by auto setup.

don0 wrote: »

I like mine better with the auto setup off and the tone controls set on 0. Speaker levels and distances were set correct by auto setup.

I just had a d

F1nut

In the above example, with 7x100 and the tweeter using only five watts, for example, wouldn't that leave 195 watts available for the woofer?

Absolutely not, the woofer would get 100 watts.

don0

"I just had a d

don0

F1nut wrote: »

Absolutely not, the woofer would get 100 watts.

I know that 195 watts is not correct since each channel will probably not go over 100 watts, but it does show that the PS has some reserve and that, in the example, there is the possibility that bi-amping could supply more than the 100 watts total to the speaker. Maybe bi-amping with the receiver is useless but it does not cause any loss other than the cost of the extra wire and might help a little, in my opinion.
I could be wrong again.

Hermitism

don0 wrote: »

Maybe bi-amping with the receiver is useless but it does not cause any loss other than the cost of the extra wire and might help a little, in my opinion.
I could be wrong again.

What the tweeters don't use gets wasted, instead of being there for the woofers/mid range, if needed.

don0

Hermitism wrote: »

What the tweeters don't use gets wasted, instead of being there for the woofers/mid range, if needed.

I do not believe that it gets wasted.

If it did, the receiver, Marantz with 100 watts x 7, would draw 700 watts from the power supply.
My AVR uses less than 70 watts, measured with power conditioner with meter, when watching a movie with all five channels on, actually 7 channels because I have them bi-amped. "I know useless."

F1nut

It's wasted in the sense that let's say the AVR can supply 100 wpc with 5 channels driven, but drops to 80 wpc with 7 channels driven when you ghetto bi-amp. So now, the woofer cannot get more than 80 watts while say 70 of of the possible 80 going to the tweeter go unused. Basically, you just robbed the woofer of 20 possible watts and we all know bass requires power, the more the better.

don0

nbrowser wrote: »

Ah the good old AVR bi-amp misconception, been there, got my learn on, went and got a high current 205wpc amp and ain't looked back. Do it right, get a real amp and watch the sound get so much better...

As I said, it might not do any good but in my opinion, it does not hurt.

don0

F1nut wrote: »

It's wasted in the sense that let's say the AVR can supply 100 wpc with 5 channels driven, but drops to 80 wpc with 7 channels driven when you ghetto bi-amp. So now, the woofer cannot get more than 80 watts while say 70 of of the possible 80 going to the tweeter go unused. Basically, you just robbed the woofer of 20 possible watts and we all know bass requires power, the more the better.

In the example in the post above where the receiver is capable of 100 watts x 7, 100 watts would be available for the woofer from one channel and 5 or more watts would be available for the tweeter when getto bi-amped.

don0

nbrowser wrote: »

The woofer wouldn't get anywhere close to 100 watts in the ghetto bi-amp, more like 80...and that would hurt the soundstage in a heartbeat.

It would get 100 watts, if needed, in the example posted earlier where the 135/per channel receiver is capable of delivering 100 watts/channel with all 7 channels driven.

FTGV

don0 wrote: »

It would get 100 watts, if needed, in the example posted earlier where the 135/per channel receiver is capable of delivering 100 watts/channel with all 7 channels driven.

That would be a worst case sceniario with all channels driven to full output with a sinewave into a resistive load.With real program material it would be a very rare event to have all channels driven to there full potential at the same instant.
Also in comparison with the power demands of the bass and lower mids reproduced by the woofers the upper midrange and treble region covered by the tweeter will only lightly load the amp sections driving them.Thus not taxing the power supply greatly, less voltage drop so stealing less power from other channels than if they were running full range.

However it is my opinion that passive biamping with an AVR provides little in the way sonic gain.The only time I think it(passive biamping) may be worthwhile is if one wants to try two amps with different sonic signatures,(ie.such as a tube amp for the tweets,SS for the woofers.)However this approach will likely lead to gain mis-matches that would need to be corrected for.

F1nut

don0 wrote: »

In the example in the post above where the receiver is capable of 100 watts x 7, 100 watts would be available for the woofer from one channel and 5 or more watts would be available for the tweeter when getto bi-amped.

That was just an example trying to make a point. I don't think that even the Pioneer Elites are capable of 100wpc with 7 driven.

That said, Fred is right that it would be a rare case where all channels were driven to the max.

The real point about bi-amping is that it requires the use of active crossovers and separate power amps, each with its own power supply, hence my use of the term ghetto bi-amping to describe what those are doing with their AVR's.