A little bit of a side topic, but how do people feel about a hardware dsp such as Linea asc48, or other pro studio controllers? No room correction, but frequency and timing control. Not sure about the AD/DA conversion, really no idea how to compare
-
WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!
DEQX Premate 8 digital active crossover / DSP
- Thread starter Keith_W
- Start date
Pro loudspeaker management systems (the industry term) work well for home active speakers as long as you're willing to deal with balanced XLR connectors and you have the appropriate measurement tools. I've been using Behringer DCX2496 processors on my first set of DIY LCR speakers for a couple of decades now. For my second set of DIY speakers I plan to use Ashly Protea 4.8 processors.
I too am a happy DEQX HDP-5 user (and been through analogue crossovers, Behringer DCX2496 before buying the HDP-5). I've a great front-end, great dacs, great amps and great transmission line speakers all in a large heavily damped room. The sound I get once I've EQ'd the speaker calibration is astonishing and never ceases to amaze me. I've had three industry experts visit and all have been most impressed. I'll be joining the beta programme for the Pre-8.
Does anybody know, perhaps from previous DEQX models how flexible the software is for delay, crossover slope, etc? They seem to be wanting to make it very turn key, user friendly, but do we know how much manual adjustment is allowed. I’m assuming not a Acurate or even Audiolense level of manual, but does DEQX allow you to tweak settings to a reasonable level?
Thanks
Thanks
From what I've been told everything can be manually controlled afterwards, thus one isn't locked to the auto correction.
I think this combination is the best. Some need the auto correction and thats important to have from a commercial standpoint. But having the ability to also manually control everything can raise the result in many cases and is important for both speaker designers and DIYers.
For the price they set for this, it should do everything but the laundry.
I've an HDP-5. To do things properly the speakers need to be calibrated (impulse response corrected/time aligned). The level of each driver will be set and the slope(s). An overall time delay can also be set for each frequency band - I asked DEQX to dial in from Australia and followed their instruction as to where to place the mic for each driver. Once that's all set you can adjust things as you play, so for each driver you can alter time delay, level (but only in 0.5db steps). You can add parametric equalisers which work across the resultant whole frequency band (this allows you to EQ the room once the speakers themselves have been calibrated). There are also some preset equalisation curves for bass mid and treble which are adjustable. If you don't want to calibrate the speakers you can simply set the crossover points and slopes. I've no idea yet what the Pre-8 will allow but to be able to autocalibrate will be great if one wants to try new amps or dacs (it has built in ESS dacs but I'll be using the coax digital outs into my own dacs). I'll be joining the beta testing in the new year when black units will be available (although silver looks nice I don't want distractions).
OP
Keith_W
Major Contributor
- Thread Starter
- #109
I had a DEQX HDP-3, but I sold it many years ago. You could choose the crossover type - at the time, there was Linkwitz-Riley, Butterworth, and Bessel. You can also choose crossover order and obviously crossover point. Mixed bandpass crossovers were possible (for e.g. 2nd order highpass + 4th order lowpass). You could compensate for delay between bands of frequencies. And of course implement an overall correction.
This is more than what you can do with Audiolense. With Audiolense, you only get one type of crossover, and you can not have mixed bandpass crossovers. I believe that Audiolense does not do individual driver correction either, it measures all the drivers independently from the MLP and then implements an overall correction. To get something more powerful and flexible than DEQX, you would have to use Acourate.
In fact there are quite a few similarities between how DEQX works and Acourate. Both of them work by "let's make your speaker as perfect as possible, and then deal with room issues" - i.e. start by driver correction and time alignment, followed by room correction.
The old software that I was using with the HDP-3 was very manual and required you to know what you were doing. I hear that newer iterations of DEQX software is more automated and more beginner friendly. With the newest Premate 8, they have rewritten the software and migrated it to the cloud, and I was told by Kim when I spoke to him that one of their major aims was to make it easier for the end user.
In my opinion, the difficulties of the old DEQX software was knowing where to place the microphone, interpreting the results, choosing crossover slopes, and so on. The software itself wasn't difficult to use, it was easy to find settings and the workflow was pretty straightforward. You just had to know what you were doing.
I think as far as software goes, Acourate is the best and the most powerful and flexible. You can tweak things that you probably can't hear. I can certainly vouch that the difference between "perfectly corrected" and "slightly imperfect" are quite difficult to hear! But DEQX software is certainly powerful enough and you can get great results with it.
Reddoc
I’m waiting to receive the Pre-8. I own a HDP-5 but took it out of my system due to the software was so difficult! But it integrated my vinyl with digital compensation. My system is fully active 3-way with active subs. If you interested I believe there is still time to get in.
Waiting for mine. No word yet on when it will be shipped, except "soon."
There's an awful lot of misunderstanding on display in this thread.
One of the main features of the DEQX is the software. It's not just about DSP. Even if you can write your own DSP code, how are you going to turn whatever measurements you make into DSP that can, for example, correct group delay? And as far as running DSP on a PC- again, it's not just about flattening FR - there's a lot of time-domain corrections to be made, which can't be done across the audio band on a MiniDSP and I wonder if people know how to do that with DSP on a Mac.... The DEQX takes a set of measurements made by the DEQX and an Earthworks mic* (not some Dayton Audio junk) and processes them on some high-powered cloud-based system, not in a less capable PC or a MAC. Then the solution is downloaded to the DEQX for implementation in DSP. I've heard that what DEQX is doing in the cloud would take days on an Apple M2 Ultra or an Intel i9-14900k. So there's that.
The other issues with PC based DSP are latency and noise. If you are using your 2-channel system for left front and right front audio for TV or movies, you'll have some picture sync issues trying to use PC based DSP if you are doing anything very complex. Hardware DSP is always faster than software. And many audio systems that contain a computer (Mac or PC) will have some amount of noise intruding into them - those switching supplies in computer generate serious hash all the way up into the low microwave spectrum. How many setups like those are going to have the -140 dB noise floor of the DEQX? ( And we know how excited Amirm gets about these impossibly low noise floors... he seems to think it matters in a playback system, and who am I to disagree?)
The only valid point that I think is being raised here is in regard to the price. YES $12k is a lot of dough. But you know there are PLENTY of analog preamps that sell for over $20,000 and they don't do very much except offer a little gain and some control. High end gear costs a lot. The DEQX is a very specialized thing, small market for those who understand what it can do - I also think some installers will be selling them too in high-end setups - but considering all the R&D that went into the new line of DEQX's, I'm actually surprised they aren't asking MORE for the things.
=========================
*Surely those who spend $12k on a DEQX will spring for the better measurement mic.
Absolutely agree. My HDP-5 works a treat and was calibrated by Alan Langford at DEQX. I'm still waiting for my Beta Pre-8. It's obvious that all the time domain stuff, the initial speaker EQ, the crossover and the user settable EQ should be done in one powerful processor.
That is some claim. Any evidence more solid than "I heard"?
And your solution to this is to write a reply adding more confusion?
I agree that software, support and a high-end integrated solution with lots of I/O are the main thing DEQX offers above its competitors. However, I think you are really selling the processing power of the competitors short. As already discussed in this thread, any platform that can implement FIR filters with adequate resolution can flatten phase. Generating these filters is easy with rePhase.
rePhase
rePhase, a loudspeaker phase linearization, EQ and filtering tool. rePhase is a free FIR generation tool for building fully linear-phase active crossovers with arbitrary slopes. It also let you manually compensate for the phase shifts of your loudspeakers and existing crossovers, be it active or...
rePhase FIR Tool
miniDSP is a leading manufacturer of Digital Audio Signal Processors for the HomeTheater, Hifi, headphone and Automotive market. Join our large community of Audiophiles, Engineers and DIYers using our innovative products.
rePhase, a loudspeaker phase linearization, EQ and FIR filtering tool
as rePhase has evolved a lot since day one of this long thread, it is certainly not a good starting point to understand what rePhase does and what its current state of development is. It is nonetheless a good place to ask questions, report bugs, or request features. This first post is kept...
These filters can be implemented on a variety of hardware systems (miniDSP, Q-Sys, etc) and software convolvers (CamillaDSP, Accourate, J River, etc). A miniDSP miniSHARC is perfectly capable of linearizing phase when running at 48 kHz. Newer miniDSP systems are certainly more challenged, as they run at 96 kHz, but running a miniDSP OpenDRC-DI upstream of Flex Eight / HT / HTx is a perfectly viable solution for phase linearization.
I won't deny that software solutions have inherently higher latency than hardware solutions, however I think you are again over selling this point.
When playing around with phase linearization the biggest issue with latency is from the FIR filters themselves, this latency will be the same regardless of whether they are implemented in a hardware or software solution. If anything, this is an argument against millions of FIR taps as they will add too much delay for A/V applications, unless you are using a completely computer-based solution that is capable of delaying video.
To add some data to the discussion, a digital input / analog output CamillaDSP solution on a RPi can easily achieve 15 ms latency. Depending on device sub-10 ms is also possible.
It will also be interesting to see what latency the ARM based DEQX is. Hardware DSP solutions usually have inherent latency of about 2-3 ms, is the ARM DEQX closer to that or more like 10-15 ms? We don't know at this point.
In any case, the best solution in terms of A/V sync is to run all channels through the same processing path (even if they are just pass through), which can't be done with the DEQX as it only has stereo input.
I don't see the point of taking the claimed -140 dB noise floor at face value. We have no details on bandwidth, weighting or output level. However, it is pretty easy to guess that if they are using one ES9038 pro as suggested by @Keith_W they won't be able to achieve that. Datasheet performance when used in an 8-channel configuration is 132 dB(A), typically an unweighted measurement will be about 3 dB worse so looking at 129 dB unweighted.
While I wouldn't run an unbalanced system connected to a computer, I see no noise degradation via measurements or listening on the multichannel DACs I use (MOTU Ultralite Mk5 and Okto dac8 pro) when connected to computer. I've measured 121 dB+ dynamic range, unweighted, 20-20K at full output (4.4 V for Okto, 8.6 V for MOTU) on both while connected to a RPi running CamillaDSP and the spectrum looks clean with no hash. Here is the MOTU as measured by a Cosmos ADC in stereo mode at 2 mV output.
Michael
I received an e-mail from DEQX yesterday informing me my Beta Pre 8 will be shipped from Australia on February 9.
I am very eager to receive it. I have been using a DEQX ever since 2004 with my fully horn loaded triamplified DIY speakers. I am a little brain damaged from two TBI in the line of duty, and I found programming the DEQX to be overwhelming. Despite that I was still able to achieve splendid results with the help of DEQXpert, Larry Owens. I knew my DEQX (a PDC2.6 I bought in 2004 later upgraded to a HDP3) was getting old, but I never even considered any other brand.
I am very eager to receive it. I have been using a DEQX ever since 2004 with my fully horn loaded triamplified DIY speakers. I am a little brain damaged from two TBI in the line of duty, and I found programming the DEQX to be overwhelming. Despite that I was still able to achieve splendid results with the help of DEQXpert, Larry Owens. I knew my DEQX (a PDC2.6 I bought in 2004 later upgraded to a HDP3) was getting old, but I never even considered any other brand.
- Joined
- Jan 7, 2020
- Messages
- 943
- Likes
- 1,256
He must have misunderstood. Otherwise extraordinary would be an understatement!
You could get around the high price tag of say the Pre-8 by generating a profile with one in your setup and then returning it to some centralized lender. The lender would then process any additional music you send them using your sound profile and rip them from the digital outs before sending back to you. Of course if you got new speakers and/or a new space you would have to rent additional time with the box.
I'm sure this would violate something legal with DEQX... but it would be difficult for them to pursue legal action in every country they sell units(that's if they caught wind of it somehow).
I'm sure this would violate something legal with DEQX... but it would be difficult for them to pursue legal action in every country they sell units(that's if they caught wind of it somehow).
OP
Keith_W
Major Contributor
- Thread Starter
- #120
There is no point doing this when there are plenty of software that do exactly the same thing. Some of them are free (like REW/rePhase). The advantage of DEQX is that it is an "all in one" system. If you have certain needs, a hardware solution like a DEQX has several advantages over a software based system like the one I am using (Acourate to make filters, convolver to host filters, all in a Windows PC). The main one being, ease of use if you need digital inputs like HDMI, external streamers, etc. and analog inputs. With a DEQX, you simply plug in the external input and away you go. With my solution, I need a HDMI converter, an external sound card, and software to route the sound around my PC for processing. It is theoretically possible, but it is not easy or convenient.
IMO the biggest argument in favour of the DEQX is the hardware.
Welcome to ASR by the way!
Similar threads
