The Active Advantage

[Blizzard]

That's a list of parts. And while it's easy to assume that better quality = better sound, why do we think that is true? At what point are the copper traces thick enough to carry all the current they will ever be tasked with? Is there a reason to go beyond that? Is there no upper limit? If an amp was grossly over spec'd in all of these parameters would it "sound better" than one that was simply built comfortably beyond it's performance requirements? Why?

Tim

I suppose some things are beyond layman's terms. Perhaps you should go listen to some quality amps and see if you can hear any difference between a $200 Crown, and a $18000 pair of Mola Mola monoblocks. If they sound the same to you, I guess that makes you a lucky guy. This hobby will be much more inexpensive for you, than for some others.

 

[Rodney Gold]

All the amp needs to be is matched to the driver , have enough power and be able to deliver it without artefacts , there are many other factors that contribute to active speakers sound .
I ran a linkwitz Orion with a 6 chan ATI beast and ran it with an old 60w/chan 6 chan rotel .. there was no difference unless you tried to go to insane levels , where the extra power of the ati (I think it was 150w) allowed it to go louder cleaner

you remind me of one of our audiophiles here .. brilliant mind , fantastic cnc skills , amazing ear.. he is developing a horn system , started 2 years ago .. but you need to nail his foot to the floor to actually get something commercially viable.. he is forever changing his mind about the "best" components to use .. his product will never see the light of day .. there is always something "better" to be used in it...

 

[Blizzard]

All the amp needs to be is matched to the driver , have enough power and be able to deliver it without artefacts , there are many other factors that contribute to active speakers sound .
I ran a linkwitz Orion with a 6 chan ATI beast and ran it with an old 60w/chan 6 chan rotel .. there was no difference unless you tried to go to insane levels , where the extra power of the ati (I think it was 150w) allowed it to go louder cleaner

Yes but you also use a squeezebox connected via SPDIF to a MiniDSP DIRAC as a front end in a $100000+ setup.

 

[Rodney Gold]

What is wrong with that.. it sounds amazing... it means that money is not the only determinant of what component is good.
If miniDSP is good enough for linkwitz , its good enough for me...
At any rate .. I have directly compared my puter running dirac into my devialet vs the SBT and hardware based DRC ... no difference at all .. however the puter does allow more taps
I have also compared my old ML31.5 transport to the SBT .. no difference and I happen to know many many people with even more expensive systems who also swear by it

If you want to talk sonics , my treated room was the best improvement and then Dirac

I compared my system to meridian DSP6000 speakers.. $phile class a for 10 years - $20k
My giyas caned it.. proving that active is not always better..

If you look closely in the pics , you can see 2 of the Yamaha subs (4 of them) and one of the pair of SVS sb 13 ultras which i use as distributed bass to smooth room nodes .. yammys were round $400 and the ultras were $1500 each.. not expensive , but OMg, they work so well

 

[Rodney Gold]

My advice to you is get a product to market.. dont stress if something isnt SOTA .. there will always be something more SOTA in a few weeks...
Nail that foot to the floor and prove the speakers worthy

One of these would be a good start for your speakers
https://www.minidsp.com/products/plate-amplifiers/pwr-dsp3

 

[Blizzard]

What is wrong with that.. it sounds amazing... it means that money is not the only determinant of what component is good.
If miniDSP is good enough for linkwitz , its good enough for me...
At any rate .. I have directly compared my puter running dirac into my devialet vs the SBT and hardware based DRC ... no difference at all .. however the puter does allow more taps
I have also compared my old ML31.5 transport to the SBT .. no difference and I happen to know many many people with even more expensive systems who also swear by it

If you want to talk sonics , my treated room was the best improvement and then Dirac

I compared my system to meridian DSP6000 speakers.. $phile class a for 10 years - $20k
My giyas caned it.. proving that active is not always better..

If you look closely in the pics , you can see 2 of the Yamaha subs (4 of them) and one of the pair of SVS sb 13 ultras which i use as distributed bass to smooth room nodes .. yammys were round $400 and the ultras were $1500 each.. not expensive , but OMg, they work so well

If I were you I would at least consider using PC based DSP and just going in through the USB port on the Devialet. This will take the cheap jittery DSP chips out of the signal path.

 

[Blizzard]

My advice to you is get a product to market.. dont stress if something isnt SOTA .. there will always be something more SOTA in a few weeks...
Nail that foot to the floor and prove the speakers worthy

One of these would be a good start for your speakers
https://www.minidsp.com/products/plate-amplifiers/pwr-dsp3

I've gone down the Minidsp path. It's midfi stuff at best. Don't worry about my plans. I already have what I'm going to do figured out.

 

[esldude]

If I were you I would at least consider using PC based DSP and just going in through the USB port on the Devialet. This will take the cheap jittery DSP chips out of the signal path.

So how low does jitter need to be not to be audible? How audible is the amount in the miniDSP stuff?

 

[Groucho]

Capacitors, resistors, diodes, 4 layer pcb's, PCB material, Thickness of copper traces, transformers, voltage regulators, relays, switches, cables, solder etc, come in several different grades. The higher quality grades are more expensive than the lower quality grades. Higher grades preform better than lower grades. This equals better sound quality. It also means better long term reliability. This all adds up to a higher BOM. On top of that, the engineers who are intelligent enough to design the best circuits charge more money. You are also paying for intellectual property, not just parts. Then there's quality control, some products undergo a much more comprehensive QC process. This costs money as well. The case can be the most expensive component in the amp. This is because many people buy based on looks. Ugly cheap looking amps just don't sell as well. Good quality well damped cases can also help dampen vibration and block EMI. This can result in better sound. Earlier I said the standard in the audio industry for products sold through dealers is BOM x 6= MSRP. So if an amp has a BOM of $1000, you can roughly expect the MSRP to be around $6000.

I love your image of a boutique, cottage industry that wires up integrated circuits following the data sheet, then creates their version of a fancy box to put it in. You make it sound like NASA, or the companies that make MRI scanners for hospitals.

 

[Rodney Gold]

ESL ..the effects of DSP , low bass correction and so forth are 10 orders of magnitude more audible than a jitter figure.
The only comparison you can make is if the minidsp is in bypass vs a non minidsp setup .. and thats really useless compared to how the sound changes with the minidsp
all talk and no action.. bring those speakers to market , manufacture them , voice them , measure them , make em look pretty , send em out for peer review , price them and see if you can sell em...

 

[esldude]

ESL ..the effects of DSP , low bass correction and so forth are 10 orders of magnitude more audible than a jitter figure.
The only comparison you can make is if the minidsp is in bypass vs a non minidsp setup .. and thats really useless compared to how the sound changes with the minidsp
all talk and no action.. bring those speakers to market , manufacture them , voice them , measure them , make em look pretty , send em out for peer review , price them and see if you can sell em...

Oh don't get the wrong idea. I agree with you. I run Room Correction myself. The advantages are knock you over the head obvious, while a lower jitter clock......ehhhh....not so much. I often refer to jitter as the audiophile equivalent of a medieval demon. Feared in a world of faith and superstition.

Yet we have someone saying jittery DSP, and such make the miniDSP devices unlistenable. How much jitter is unlistenable? Seems to me it would be an awful lot more than the miniDSP devices have. Yeah 10 orders of magnitude might not be far from wrong. Of course I think of my old reel collector friend upon hearing the old Stereophile CD with a track featuring a 100th gen copy of an original digital file. Presumably it would have had mucho jitter too. He grinned, and said, "man can you imagine if that were 15 ips reel tape. You literally would not know what it was a 100th generation of."

 

[Blizzard]

So how low does jitter need to be not to be audible? How audible is the amount in the miniDSP stuff?

I don't know but they sound like a circa 1988 Pioneer CD player to me. Poor S/N ratio as well. The Hypex DSP boards are better, but still, not high end audio worthy IMO.

 

[Blizzard]

ESL ..the effects of DSP , low bass correction and so forth are 10 orders of magnitude more audible than a jitter figure.
The only comparison you can make is if the minidsp is in bypass vs a non minidsp setup .. and thats really useless compared to how the sound changes with the minidsp
all talk and no action.. bring those speakers to market , manufacture them , voice them , measure them , make em look pretty , send em out for peer review , price them and see if you can sell em...

Yes but you can preform all the features minidsp stuff can do and more with PC based DSP, without putting any of this nasty circuitry in the signal path. Most people use a computer in their system anyways. Might as well put it to more use.

 

[Phelonious Ponk]

I suppose some things are beyond layman's terms. Perhaps you should go listen to some quality amps and see if you can hear any difference between a $200 Crown, and a $18000 pair of Mola Mola monoblocks. If they sound the same to you, I guess that makes you a lucky guy. This hobby will be much more inexpensive for you, than for some others.

I don't think I asked any question in the post you answer above that could not be answered in layman's terms, but OK.

Tim

Tim

 

[Robh3606]

I am currently working on a passive version of the JBL M2. You would be quite surprised how flat you can get well made components with a passive network. It won't be as ruler flat as a DSP version as the EQ required would be beyond what is possible with passives. I am a believer in actives and passives. There is plenty of room for both. Here are some measurements and sims so you can see what I am talking about. I wouldn't argue that either is better in a real world application unless you are talking SR work where active really is a must. It's all about application and results and you can do fine with both.

Rob

 

[esldude]

I am currently working on a passive version of the JBL M2. You would be quite surprised how flat you can get well made components with a passive network. It won't be as ruler flat as a DSP version as the EQ required would be beyond what is possible with passives. I am a believer in actives and passives. There is plenty of room for both. Here are some measurements and sims so you can see what I am talking about. I wouldn't argue that either is better in a real world application unless you are talking SR work where active really is a must. It's all about application and results and you can do fine with both.

Rob

Why? Why go passive with a speaker designed for active?

 

[Robh3606]

Why? Why go passive with a speaker designed for active?

Hello esldude

Why not?? This is a hobby and I enjoy the challenge of doing it. It's fun. I have to take measurements load them into LEAP design the crossovers and build them. With the cabinets same thing, go into a box program like Bass Box and run the woofer simulations then build the cabinets. It's work but its all worth it when you power things up and you like what you hear.

I have converted passive systems over to biamp systems using an active analog crossover, JBL DX-1, just had to build custom cards so the voltage drives match. Once you match the voltage drives you will have identical crosssover characteristics so the response is is the same as the passive version. I am not trying to build a clone I am using an upgraded large format compression driver on the same horn and using the same woofers. When I built my 1400 Array systems I used charge coupled networks, as opposed to the stock ones and the Beryllium drivers from the 9800 as opposed to the Aluminum and Titanium drivers in the stock systems.


Trying to use the stock DSP settings is not possible using a different compression driver in this case the 476Mg from the 9900. The EQ will not match and the lower range frequency response on the waveguide is different. The crossover between the woofer and waveguide will need to be changed. I know there are plenty of reasons why active is theoretically better. Having done passive and bi-amped versions on the 4344 monitors and converting L250Ti to Biamp, and running XPL200's in both passive and Bi-amp configurations I can easily live with both. In my experience the differences were subtle if audible at all.

Rob

 

[esldude]

Why? Why go passive with a speaker designed for active?

Hello esldude

Why not?? This is a hobby and I enjoy the challenge of doing it. It's fun. I have to take measurements load them into LEAP design the crossovers and build them. With the cabinets same thing, go into a box program like Bass Box and run the woofer simulations then build the cabinets. It's work but its all worth it when you power things up and you like what you hear.

I have converted passive systems over to biamp systems using an active analog crossover, JBL DX-1, just had to build custom cards so the voltage drives match. Once you match the voltage drives you will have identical crosssover characteristics so the response is is the same as the passive version. I am not trying to build a clone I am using an upgraded large format compression driver on the same horn and using the same woofers. When I built my 1400 Array systems I used charge coupled networks, as opposed to the stock ones and the Beryllium drivers from the 9800 as opposed to the Aluminum and Titanium drivers in the stock systems.


Trying to use the stock DSP settings is not possible using a different compression driver in this case the 476Mg from the 9900. The EQ will not match and the lower range frequency response on the waveguide is different. The crossover between the woofer and waveguide will need to be changed. I know there are plenty of reasons why active is theoretically better. Having done passive and bi-amped versions on the 4344 monitors and converting L250Ti to Biamp, and running XPL200's in both passive and Bi-amp configurations I can easily live with both. In my experience the differences were subtle if audible at all.

Rob

So you aren't going to convert an M2 to passive. You are using very similar parts and doing a very similar speaker. That is a horse of a different color.

 

[Groucho]

There are several different levels of active speaker, culminating in the configuration that provides high power DSP for each driver. Even then, there are different levels of how far the DSP software goes - starting with simple "EQ" and culminating in full driver correction. The price to put in place the complete package is pretty low.

Once the system is in place, I think the truly interesting questions are:

- just how does the shape and slope of a crossover affect the sound? What are the advantages and disadvantages of super-steep crossovers, for example?
- is there a disadvantage to individual driver phase correction i.e. is individual driver 'pre-ringing' audible (even though it is cancelled out by adjacent drivers' own 'pre-ringing')
- what is the best way of implementing in-room EQ? (e.g. baffle step)
- can we make the speaker work well regardless of location in the room?
- what are the merits of digital room correction?
- ambiophonics etc.?

The provision of general purpose DSP allows us to do all these things, and allows us to design a different speaker. The pre-ringing question might have a different answer if we build a four-way as opposed to two-way, because the dispersion characteristics of the drivers will be better matched through the crossovers, for example. DSP makes four-way design as simple as two-way, so this is something we can do easily.

We can't meaningfully conclude that "active sounds no different from passive" unless we follow it all the way through.

 

[Robh3606]

No I am scratch building the system using components. I have the M2 waveguides 2216 woofers but not the 2430 compression drivers. I already had the 476Mg's before the M2 components became available for purchase. I am very surprised that the drivers and waveguides are available for sale. The M2 has a passive network that consists of a resistor attenuator on the compression driver as well as a series protection capacitor that acts like a pole for the high pass filter. So contrary to what you might see on forums it is not a pure DSP effort. Take out the passive network and the system won't work.

Rob