Hello guys,
I would like to ask for some suggestions and help to start a project for 3-way DSP controlled speakers using DEQX.
A few words on what I am after. About the only commercial speakers that I liked to some extent were active ATCs and most recently the new DSP controlled PMC IB2.
Both had some issues though.
Would I be better off with an attempt activate an existing commercial passive speaker, let’s say passive PMC IB2, or start from scratch?
I do not posses lots of experience and knowledge, so if a new design has significantly higher potential for great sound that would surpass those commercial offerings, I would probably commission someone with proven record and lots of experience to design enclosure, possibly build it as well.
Considering my preferences, can you make suggestion on a set of drivers that I should consider? Size wise I am thinking 70 liters box. I guess I could start with ATC sm75-150s as mid, what would complement them well? Or is there something else that I should consider for midrange? As far as ATC mid dome goes, it sounds almost perfect in ATC implementations, but there is a kind of hardness to the sound, I do not know if it is due to the resonance that some mentioned here around 4.5kHz that is still audible because of too high crossover point chosen by ATC (3.5kHz) or it is simply its trait? What else is there that can measure up? Is Audio Technology good, would their polypropylene cones be too dark and not so lively?
I would like to ask for some suggestions and help to start a project for 3-way DSP controlled speakers using DEQX.
A few words on what I am after. About the only commercial speakers that I liked to some extent were active ATCs and most recently the new DSP controlled PMC IB2.
Both had some issues though.
Would I be better off with an attempt activate an existing commercial passive speaker, let’s say passive PMC IB2, or start from scratch?
I do not posses lots of experience and knowledge, so if a new design has significantly higher potential for great sound that would surpass those commercial offerings, I would probably commission someone with proven record and lots of experience to design enclosure, possibly build it as well.
Considering my preferences, can you make suggestion on a set of drivers that I should consider? Size wise I am thinking 70 liters box. I guess I could start with ATC sm75-150s as mid, what would complement them well? Or is there something else that I should consider for midrange? As far as ATC mid dome goes, it sounds almost perfect in ATC implementations, but there is a kind of hardness to the sound, I do not know if it is due to the resonance that some mentioned here around 4.5kHz that is still audible because of too high crossover point chosen by ATC (3.5kHz) or it is simply its trait? What else is there that can measure up? Is Audio Technology good, would their polypropylene cones be too dark and not so lively?
Law of the 5-Ps ....
.... is a military term, that applies here as well.
Incorporating a DSP Crossover into your design strategy provides wide latitude in driver selection and the flexibility required to arrive at an optimal design given the drivers you eventually select. Give consideration to the following when proceeding with driver selection and the rest of system design:
1) Are subwoofers to be used?
This will affect the LF driver selection for the satellites.
2) Will ATC sell you the drivers you want?
Here I would suggest you expand your horizons to include other manufacturers’ products.
3) Set a project budget and proportion it by frequency channel.
You have three decades to cover, make sure adequate funds are available for each.
4) Maintain control of the design. You can do it. Just let others and your ears critique what you come up with. Do a lot of reading and auditing when selecting drivers. Gain an understanding of driver parameters, so you can boil-down the candidate list to just a few to listen to.
5) Design is an iterative process, so traversing circles should be anticipated.
The issues addressed here, do not represent a comprehensive list of those you will encounter during the course of your project, but they should serve as a determinant for what will certainly follow.
Regards and Good Luck,
WHG
.... is a military term, that applies here as well.
Incorporating a DSP Crossover into your design strategy provides wide latitude in driver selection and the flexibility required to arrive at an optimal design given the drivers you eventually select. Give consideration to the following when proceeding with driver selection and the rest of system design:
1) Are subwoofers to be used?
This will affect the LF driver selection for the satellites.
2) Will ATC sell you the drivers you want?
Here I would suggest you expand your horizons to include other manufacturers’ products.
3) Set a project budget and proportion it by frequency channel.
You have three decades to cover, make sure adequate funds are available for each.
4) Maintain control of the design. You can do it. Just let others and your ears critique what you come up with. Do a lot of reading and auditing when selecting drivers. Gain an understanding of driver parameters, so you can boil-down the candidate list to just a few to listen to.
5) Design is an iterative process, so traversing circles should be anticipated.
The issues addressed here, do not represent a comprehensive list of those you will encounter during the course of your project, but they should serve as a determinant for what will certainly follow.
Regards and Good Luck,
WHG
The ATC SM75-150S is a very expensive proposition now, its a whisker over £300 each here in the UK.
A comparable Audio Technology driver would be the excellent C-Quenze 15 H 52 12 06 SDKM which is a dedicated midrange or alternatively if you don't require a 91dB sensitivity then the C-Quenze 15 H 52 06 13 SDKAM is 89dB and has a flatter response. Price wise the AT drivers are cheaper than the ATC but not by a huge amount(£220each UK).
In terms of comparisons they're both strong drivers when used correctly but I prefer the AT's for their more refined character and very bandwidth performance. My main issues with the ATC are its limited bandwidth and pretty ragged response which pigeon holes it into pretty much one crossover configuration - approx 500hz to 3Khz with fairly steep filters such as 24dB/oct or greater. The AT on the other hand is nicely flat across its usable range and can extend happily down to 150hz and all the way up to 5Khz and beyond. This flat and extended pass band is great for low order filters and general crossover design flexibility. As for the dark quality sometimes associated with poly cones, the AT's have none of that I've heard. I do think the debate over the contribution to colouration from cone material is often overstated. I've used many including magnesium, poly, paper, ceramic, cloth, aluminium and so on. My observation is that good drivers have more in common than not regardless of cone material.
What the ATC is capable of is hard to ignore and the AT aren't quite as dynamic sounding but as you've already pointed out this dynamic ability comes about as a certain forward nature that can be tiring on long listening sessions.
WHG has some good suggestions, I would like to add my DSP experience.
The DEQX is overpriced and limited compared to what you can accomplish with a dedicated PC. The DEQX is basically a botique version of a pro audio active XO. Using Audiolense or Accourate you can get a very good sounding system in 15 minutes, maybe 90% of it's ability. Audio Lense, which is what I use, does not look at DSP XO the same way that the DEQX does. The DEQX is a 1 through 8 pole DSP, max 48 db/oct, Audiolense has an almost infinite amount of slopes, and is not limited to classic filter design.
Subjectively, using a PCXO with Audiolense, the sound is like a good pair of headphones. Imaging is unreal! Flat frequency and phase response, without any pre-ringing, pretty much the holy grail of XO and frequency correction.
I have not used the newest version of Accourate, but it similar except the fact that it uses traditional crossover slopes, LR, butterworth, etc.
As far as the ATC drivers go, I think that Solen still sells them. I would build a system from scratch, and the ATC mid would be a good place to start. I wouldn't bother with the Audio Technology drivers, all of the measurements that I've seen of them are good, but not great, and certainly far below the price tag. I would look at the Acoustic Elegance drivers, they seem to be the best of the best. I have AE 15s and 10s and they are beasts...
I could give you details of a fool proof PC setup. I've been running my PC system for about 6 years now, and it's dialed in. I know for many Hi-Fi nuts making a PC your source/XO might seem subpar as far as audio quality, but it is the cutting edge. Pro Audio sound cards are top notch and I would stack them up against anything the so called "Hi-Fi industry" has to offer.
Rob
The DEQX is overpriced and limited compared to what you can accomplish with a dedicated PC. The DEQX is basically a botique version of a pro audio active XO. Using Audiolense or Accourate you can get a very good sounding system in 15 minutes, maybe 90% of it's ability. Audio Lense, which is what I use, does not look at DSP XO the same way that the DEQX does. The DEQX is a 1 through 8 pole DSP, max 48 db/oct, Audiolense has an almost infinite amount of slopes, and is not limited to classic filter design.
Subjectively, using a PCXO with Audiolense, the sound is like a good pair of headphones. Imaging is unreal! Flat frequency and phase response, without any pre-ringing, pretty much the holy grail of XO and frequency correction.
I have not used the newest version of Accourate, but it similar except the fact that it uses traditional crossover slopes, LR, butterworth, etc.
As far as the ATC drivers go, I think that Solen still sells them. I would build a system from scratch, and the ATC mid would be a good place to start. I wouldn't bother with the Audio Technology drivers, all of the measurements that I've seen of them are good, but not great, and certainly far below the price tag. I would look at the Acoustic Elegance drivers, they seem to be the best of the best. I have AE 15s and 10s and they are beasts...
I could give you details of a fool proof PC setup. I've been running my PC system for about 6 years now, and it's dialed in. I know for many Hi-Fi nuts making a PC your source/XO might seem subpar as far as audio quality, but it is the cutting edge. Pro Audio sound cards are top notch and I would stack them up against anything the so called "Hi-Fi industry" has to offer.
Rob
DSP/PC
Digi Rob,
I am interested in what you done here as I need to build several new PCs for PA work. I want to add a Karaoke front end to them as well.
I build all my PCs from scratch using motherboards, power supplies and cases from SuperMicro. What sound cards are you using? Software?
Regards,
WHG
Digi Rob,
I am interested in what you done here as I need to build several new PCs for PA work. I want to add a Karaoke front end to them as well.
I build all my PCs from scratch using motherboards, power supplies and cases from SuperMicro. What sound cards are you using? Software?
Regards,
WHG
Shin,
If I could not get ATC SM75-150S, would there be any performance penalties with non S version?
At this time only standard version is available from Solen.
If I could not get ATC SM75-150S, would there be any performance penalties with non S version?
At this time only standard version is available from Solen.
Supermicro is a good choice, I've used many Supermicro and Tyan MBs in the past. My HTPC that does all of my audio processing uses a Gigabyte GA-MA790XT, with an AMD X4 @ 2.8 GHz and 8 GB of RAM. I use an Echo Audiofire8 as my soundcard. It's a firewire based soundcard with a solid all aluminum chassis. I have a few other sound cards that I've tried over the years and the Echo is my favorite and most reliable.
I use Plogue Bidule as my VST host, I started with Console but it wasn't very stable, plus Bidule has more useful features than Console. Within the VST host I use Voxengo Pristine Space. I use Voxengo products for pro audio applications and gave it a try, it's perfect for XO applications. There are some other VST convolution plugins out there that are free but I really like the interface of Pristine Space. And Foobar seals the deal, by far the best audio player made, and it's free.
Here's the audio chain: Foobar>Bidule>Pristine Space>Echo Audiofire>Preamp>Amps I also run my Cable DVR into my stereo for watching TV. The cool thing about feeding the DVR into the PC is I can throw a compressor in the VST host and it will stop the obnoxiously loud commercials from driving me up a wall.
Rob
I can't really recommend the standard version. I tried both in the same design and whilst they share the same traits it is audibly inferior to the super version.
Here's a couple of shots to shot just how much larger the motor is on the super.
Attachments
I'm not sure where your getting you information on the DEQX from.
The DEQX filters are based on taps (approx 4096 correction points per channel) just like the filters generated by Acourate and Audiolense. The filter slopes are variable from 12dB upto 300dB/oct linear phase.
I'm also not sure how the DEQX can be branded a boutique version of anything whether it be from the pro audio arena or the home one. It stands on its own because no other single standalone box handles the same set of problems like the DEQX does. You can get boxes that do portions of what the DEQX does but the feature sets aren't as complete.
As far as the DEQX vs. PC comparison goes. The PC has the edge in sound quality but only with reasonably high end partnering equipment and its not without complications that the DEQX simply doesn't suffer from. When I used Acourate for my filters it took considerable effort to get a useful processing platform for both audio and video application and even then it wasn't perfect and required a set of IIR filters for AV and FIR filters for audio only. In comparison I have no issues with the DEQX, the FIR filters have low delay so I can use it with AV applications and its pretty much set and forget.
So its for me the switch from PC to DEQX has been a trade of a small amount of sound quality for ease of use.
If your comparing costs the PC setup I had at the peak cost a good amount more than the DEQX too but I do concede that the PC route can be very economical yet still sound fantastic.
BTW I still think if your after the ultimate quality the PC route can offer that but its neither cheap nor is it a set and forget solution when it comes to processing audio and video.
Ribbon Instead?
Have a look at this.
ORCA Design & Manufacturing
Regards,
WHG
I can't really recommend the standard version. I tried both in the same design and whilst they share the same traits it is audibly inferior to the super version.
Here's a couple of shots to shot just how much larger the motor is on the super.
Have a look at this.
ORCA Design & Manufacturing
Regards,
WHG
Shin,
Can you describe audible inferiority of standard version, where does it fall short when compared to super version?
Can you describe audible inferiority of standard version, where does it fall short when compared to super version?
Would the mention Raven (or RAAL) integrate well with ATC mid? Aren’t those still inferior to dome tweeters when it comes to wide and uniform dispersion?
The only physical difference between the two drivers is the motor. The super has a higher BL so its sensitivity increases. This manifests as a drop in dynamics and some low level detail is lost. It turns an excellent driver into a good one but there's a lot of those around and for less.
DEQX states on their website that it has 8 pole capability,
"DEQX provides 8-pole filters (48dB/octave) maintaining linear-phase and controlling undesirable driver excursions. This way we retain each driver’s best-case resolution while providing some driver overlap." Possibly 8 Pole plus FR correction will get you to 300db/oct?
and uses a 32 bit SHARC DSP, not really earth shattering. The Behringer DCX uses similar SHARC DSPs and convolution files can be uploaded to it. 4096 taps is pretty weak compared to over 131,000 Audiolense can create. I'm not saying 131,000 taps are needed, just there is you want to use them.
I have tried an older version of Accourate, Audiolense has a superior workflow and results. I don't have any issues with delay when I watch Blu-Ray discs on my PC (which is connected to a projector). Like you I have two filters I use, one FIR and one IIR, and it takes 10 seconds to swap them. BTW, the Audiofire uses IIR DACs too...
I don't see the DEQX as a bad product, it's just not anything special for the price. For $2K I can get greater performance than the DEQX, have flexibility, a top notch front end, tinker with new software, blah blah blah... I'm not sure how well the DEQX measures speakers but Audiolense is pretty amazing at doing in room measurements. I'm not quite sure how the processing is done for the sweeps but it much better than anything I've seen for in room measurements below ~300 Hz. Not to mention it will generate a composite correction based on multiple measurements.
Guys,
What do you think would yield better results in the end, a project from scratch, or taking used PMC IB2S and activating it (here you can see details: http://www.6moons.com/audioreviews/pmc2/ib2.html)?
PMC mid dome is their own version (but in all likelihood Volt dome), cheap Vifa tweeter, and bass in TL, a nice package.
What do you think would yield better results in the end, a project from scratch, or taking used PMC IB2S and activating it (here you can see details: http://www.6moons.com/audioreviews/pmc2/ib2.html)?
PMC mid dome is their own version (but in all likelihood Volt dome), cheap Vifa tweeter, and bass in TL, a nice package.
I'd suggest a project from scratch. I'll second whgeiger's point about DSP allowing drivers to be selected more or less purely for sound quality; the approach has worked well for me.
Not sure about the quote but I can say the crossover isn't fixed to any number of poles, its flexible as are the crossover types.
You can read about the crossovers on their webpage here:
DEQX Digital Crossovers
The first paragraph from that link reads: In addition to detailed correction of loudspeaker frequency response, phase and group delay timing errors, DEQX’s ‘active’ implementation also provides extremely steep linear-phase crossovers to 300 dB/octave
The unit has dual SHARC's. A single SHARC isn't powerful enough for room correction, driver correction and crossover.
4096 correction points per driver is weak? Initially you'd think so after using the huge number of taps that Acourate and Audiolense offer but after you use them you realise its not a big deal at all. Besides its a good blend to create FIR filters with only around 10ms delay thus allowing real time playback yet still giving a large number of correction points.
For reference I've had Acourate filters with up to 65536 taps for 48Khz filters and 131072 taps for 96Khz. Did it sound better because of these large numbers? Dunno but if it did it got lost in the million and one other variables and was never a something that I thought meaningfully contributed to the sound quality.
Maybe when 192Khz becomes more common place then larger number of taps will be desirable but for 96Khz and lower 4096 is more than enough to get the EQ resolution close enough to the target frequency. The only situation where I can imagine huge number of taps being useful is for a very brute force correction where your aiming to hammer out every last deviation. Like EQ'ing comb filtering for example. Good correction is much more subtle than that though and that's why 4096 taps works perfectly well. Also its not that long ago studios used to think a 64 band stereo EQ was 'enough'. 🙂
I'd consider Acourate the more powerful of the two but yes Audiolense is easier to use and has closed the gap since its initial release. As for the filter swapping, 10 seconds doesn't sound so bad but I'd rather not have that particular ritual every time we switch from music to playing a movie or game or some utube clip etc. It depends on your tolerance for that sort of thing as to whether you can put up with it.
The DEQX software is PC based (you connect the DEQX via USB to a PC for setup) and has been evolving over time pretty much like any other piece of software. The latest version is fairly streamlined and easy to use but does allow flexibility that approaches the PC route. There's a high and low level approach to the software. On one hand you have the wizard based setup which guides you through the steps of a particular process and on the other it allows you to get into all the variables and set by hand.
The measurement side of things are fairly comprehensive and on a par with Acourate/Audiolense. To get going you plug the mic into the DEQX, connect the DEQX to the PC and run the software. You get everything apart from harmonic distortion data which I do wish they'd put into the software so I didn't have to carry on using other measurement programs for that particular task.
I do think the DEQX at $2k isn't exactly cheap but they've pretty much got the market to themselves when it comes to features and ease of use. If they could get it down to $1k then that's when its going to become more widely adopted. The PC side of things allows homebrew setups for less cost but its less elegant too so you've always got some compromise to make.
For me there was something cool about replacing several programs, a watercooled PC case, a Lynx Aurora 16 DAC, a RME Fireface 800 and an Antelope Isochrone Clock with a case that takes up one shelf on the rack and yet doesn't give up much in the way performance.
If you enjoy PC's then by all means go for it. The DEQX is another valid alternative for those looking for a more streamlined approach.
I'd go it on your own. The IB2 is a nice speaker but the components don't justify the price tag. A lot of your money is going into the badge.
If your DIY'ing the finish might not be as pretty but that all depends on your finishing skills of course. If your going with DSP for the crossover then I'd say your chances of success are high. All you need is time and the internet to do some research and you'll have something that will equal or better the IB2.
Shin,
It seems you had quite a lot experience with AT and ATC.
Can you give me your thoughts on Troels Prelude (http://www.troelsgravesen.dk/PRELUDE.htm)?
If you were to build again a DSP controlled pair of speakers with DEQX, would you do Troels like setup with AT, or your 'Perceive' like setup with ATC, from performance point of view?
It seems you had quite a lot experience with AT and ATC.
Can you give me your thoughts on Troels Prelude (http://www.troelsgravesen.dk/PRELUDE.htm)?
If you were to build again a DSP controlled pair of speakers with DEQX, would you do Troels like setup with AT, or your 'Perceive' like setup with ATC, from performance point of view?
The Prelude looks like a modern take on the classic 3-way such as the ATC SCM50.
I imagine its a very good design looking at the ingredients but having never heard it I can't offer much more than that.
I prefer the AT drivers to the ATC but both are strong performers.
I imagine its a very good design looking at the ingredients but having never heard it I can't offer much more than that.
I prefer the AT drivers to the ATC but both are strong performers.
- Status
- Not open for further replies.