Is there a particular reason why you think this would be beneficial?
-
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!
Introducing Directiva - An ASR open source platform speaker project
- Thread starter Rick Sykora
- Start date
Is there a particular reason why you think this would be beneficial?
somebodyelse
Major Contributor
- Joined
- Dec 5, 2018
- Messages
- 3,745
- Likes
- 3,032
Compare the schematic of the opamp version he originally modeled with the ESP Project 09 and you'll find they're very similar, and the boards similarly flexible, if that's the route you want to go. That way you won't need a load of matched transistors. Other crossover projects may be more suitable depending on the speaker. I'd go the DSP route though - much more flexible and easier to adjust.
Not necessarily 'beneficial' but simply another option. Some people, for example, believe the MiniDSP 2x4HD is not of high enough quality, but would still prefer an active solution. Others may want analogue but not passive etc.
I have used the Pass active crossover with my LXminis since I have a NAD C658 doing the dac/streamer duties but can't do the crossover. Adding a minidsp adds another AD/DA stage which I prefer to avoid. Using the minidsp alone means I lose a couple of inputs and Dirac. So the active crossover is a more flexible option for me. Not necessarily better but different.
But once it's adjusted I've found the Pass crossover more flexible (signal routing-wise with other gear) with my LXminis. I also kid myself it sounds better but let's not go there ... ;-)
I just found your responses to be frankly pointless and add nothing of value to this thread or the building process.
There is no point in telling someone 'Speaker building requires wisdom and experience' specially this late in the process because at best it will have no influence whatsoever on the person and at worst it will make them feel as if they're not good enough or incompetent for the task.
We should think about the consequences of our actions, you feel me?
OP
- Thread Starter
- #567
@tktran303 I know my ASR role and my capabilities. I am not offended, but would prefer to keep the build thread focused on what it takes to build r1. I think you misconstrued some of the earlier posts, so just to clarify, here is my response.
You stated…
The response was in reference to this speaker being as good or better than Rick Craig's Purezza. If this implies that because one can fine tune a speaker with a DSP and get a nice looking spinorama- it will be as good or better than another speaker.
Well I politely disagree.
Not sure where the disagreement stems here, but I have tried to be very clear that the goal of Directiva is to apply solid speaker engineering practices to learn about speaker design and (hopefully) yield a usable speaker platform. I think r1 is a competent design, but it is just an iteration. If it turns out to be good or even great, it is a group project and the credit belongs to the team.
What the NFS has confirmed is that the simulation by @ctrl is reasonably accurate to the level of +/-1 dB. That's great.
But some lines (or graphs or descriptive words), as useful as they are, for comparison, do not fully describe the listening experience. There are limitations. Sure, measurements have come leaps and bounds over the past 2 decades due to better software, knowledge of important of power response or dispersion, more affordable computers and audio interfaces, microphones.
So anyone who would like to learn to have a play at crossover design can do it, including myself:
https://www.diyaudio.com/forums/mul...purifi-woofer-speaker-builds-post6571335.html
You clearly have some experience and constructive feedback is welcome. However, this is a build thread and for those who are just trying to follow the build, this is clutter. Please either post to the general Directiva thread or feel free to start another thread.
But I have no illusions about building and end-game speaker. It's a journey. It's growth and knowledge.
Your goals are comparable to the Directiva ones, but as mentioned, this iteration is nearing an end. If you want to join the team and add to the next phase, PM me and will figure something out.
It doesn't matter how good the woofer or tweeter or other components are, voicing the system with the crossover is all-important. Some would say it's the most important.
This is why experience crossover designers like Rick Craig, Dennis Murphy and Andrew Jones get repeated work for designing great speakers, with very basic and low priced components, all the way to the state of the art parts, and have been doing so for decades...
No doubt experience is valuable. Many of these designers (and many others) have also made great contributions to DIY. As Directiva is open, I hope that they can or will contribute to the effort. My Directiva role is to define direction and leverage members with helpful expertise. As I have built the only 2 r1 speakers to date, the initial voicing will be done by me. I expect we will tweak after Amir reviews and then others are welcome to take it to the next level.
So if you are looking for a brand name designer, sorry to disappoint but Directiva is probably not the project for you. Is their involvement absolutely necessary to have a valuable outcome? I do not think so, but if you think otherwise, feel free to acquire one of their designs and enjoy!
You stated…
The response was in reference to this speaker being as good or better than Rick Craig's Purezza. If this implies that because one can fine tune a speaker with a DSP and get a nice looking spinorama- it will be as good or better than another speaker.
Well I politely disagree.
Not sure where the disagreement stems here, but I have tried to be very clear that the goal of Directiva is to apply solid speaker engineering practices to learn about speaker design and (hopefully) yield a usable speaker platform. I think r1 is a competent design, but it is just an iteration. If it turns out to be good or even great, it is a group project and the credit belongs to the team.
What the NFS has confirmed is that the simulation by @ctrl is reasonably accurate to the level of +/-1 dB. That's great.
But some lines (or graphs or descriptive words), as useful as they are, for comparison, do not fully describe the listening experience. There are limitations. Sure, measurements have come leaps and bounds over the past 2 decades due to better software, knowledge of important of power response or dispersion, more affordable computers and audio interfaces, microphones.
So anyone who would like to learn to have a play at crossover design can do it, including myself:
https://www.diyaudio.com/forums/mul...purifi-woofer-speaker-builds-post6571335.html
You clearly have some experience and constructive feedback is welcome. However, this is a build thread and for those who are just trying to follow the build, this is clutter. Please either post to the general Directiva thread or feel free to start another thread.
But I have no illusions about building and end-game speaker. It's a journey. It's growth and knowledge.
Your goals are comparable to the Directiva ones, but as mentioned, this iteration is nearing an end. If you want to join the team and add to the next phase, PM me and will figure something out.
It doesn't matter how good the woofer or tweeter or other components are, voicing the system with the crossover is all-important. Some would say it's the most important.
This is why experience crossover designers like Rick Craig, Dennis Murphy and Andrew Jones get repeated work for designing great speakers, with very basic and low priced components, all the way to the state of the art parts, and have been doing so for decades...
No doubt experience is valuable. Many of these designers (and many others) have also made great contributions to DIY. As Directiva is open, I hope that they can or will contribute to the effort. My Directiva role is to define direction and leverage members with helpful expertise. As I have built the only 2 r1 speakers to date, the initial voicing will be done by me. I expect we will tweak after Amir reviews and then others are welcome to take it to the next level.
So if you are looking for a brand name designer, sorry to disappoint but Directiva is probably not the project for you. Is their involvement absolutely necessary to have a valuable outcome? I do not think so, but if you think otherwise, feel free to acquire one of their designs and enjoy!
OP
- Thread Starter
- #568
Taking a bit of my own advice, will use the general Directiva thread to discuss my approach to optimizing this speaker. Am intentionally avoiding use of the term “voicing” as it seems to impart that there is some magic and/or designer shaping that it takes to make a great speaker.
This forum has demonstrated that even some speakers with highly regarded pedigrees do not always yield better results. Whether the designer is to blame or other factors prevented a better outcome, many of us are using DSP to optimize the sound of our speakers (hopefully for more accurate sound). This is often because of limitations in placement or other room characteristics. In this regard, it seems to me that most environments are heterogenous and likely to significantly alter any frequency domain ”voicing”. More in the general Directiva thread.
This forum has demonstrated that even some speakers with highly regarded pedigrees do not always yield better results. Whether the designer is to blame or other factors prevented a better outcome, many of us are using DSP to optimize the sound of our speakers (hopefully for more accurate sound). This is often because of limitations in placement or other room characteristics. In this regard, it seems to me that most environments are heterogenous and likely to significantly alter any frequency domain ”voicing”. More in the general Directiva thread.
Last edited:
OP
- Thread Starter
- #569
As @ctrl and I have been discussing “voicing“ of Directiva r1, and it fell on me to do, thought I would to set expectations for my approach. My primary goal is to optimize the design and not so much give it any subjective timbre. So, my primary focus is to improve upon how well the driver’s integrate and eliminating any anomalies that may crop up. This includes phase, distortion, lobing and any glaring noise or resonance issues that are found. Much beyond that I am not as clear about other response preference curves or tilts as they seem more subjective to me.
While I cannot help but to interject some of my own judgements into the design, my plan is to do so as objectively as possible. Given that minidsp HD allows 4 different configurations, am thinking will supply with a minimalist crossover, and one with ASR tuning (based on Harman research). Am thinking the other 2 slots may be different bass rolloffs for near and away use, but am open to ideas.
While I cannot help but to interject some of my own judgements into the design, my plan is to do so as objectively as possible. Given that minidsp HD allows 4 different configurations, am thinking will supply with a minimalist crossover, and one with ASR tuning (based on Harman research). Am thinking the other 2 slots may be different bass rolloffs for near and away use, but am open to ideas.
Last edited:
OP
- Thread Starter
- #571
Good thought, but am thinking an in-wall version is likely different enough to deserve its own set of configs. Had previously considered leaving an open slot for a individualized config, but figured it would be better utilized as part of a more turn-key approach.
Anyone who is willing to configure the plug-in is technical enough to either delete a slot or load a whole new configuration.
@Rick Sykora how does the sensitivity look like so far? the last speaker with the purifi woofer Amir had was lower than 84 dB / 2.83V which is really tragic for home Cinema use.
I was thinking of using the speakers for living room / home cinema situation but I'm a little concerned about sensitivity.
I was thinking of using the speakers for living room / home cinema situation but I'm a little concerned about sensitivity.
OP
- Thread Starter
- #573
Last time sensitivity was brought up there seemed to be some question over my claimed result. So, I went back and set up the SPK5 and measured the same way I do for Directiva. The SPK5 measured around 83 dB. Since this is what Amir measured for the same speaker, I know my results are comparable to his Klippel results.
With the crossover developed by @ctrl, am getting a bit over 90 dB at 2.83V/1m. Am expecting it will stay around that number when Amir measures.
Last edited:
Last time sensitivity was brought up, there seemed to be some question over my claimed result. So, I went back and set up the SPK5 and measured the same way I do for Directiva. The SPK5 measured around 83 dB. Since this is what Amir measured for the same speaker, I know my results are comparable to his Klippel results.
With the crossover developed by @ctrl, am getting a bit over 90 dB at 2.83V/1m. Am expecting it will stay around that number when Amir measures.
Do you think you can convince Amir to do some compression tests with the review? I've been looking for a small Speaker that can do ~115 dBSPL at 1 meter (above 100Hz) with sensible sensitivity to boot.
I feel like the purifi woofer puts the speaker in the same weight category as big speakers.
115dB is a lot.
90dB sensitivity means you’d need ~300W.
in Home Cinema your speakers need to do peaks of 105 dB and I sit 3-4 meters from the TV so that's pretty much what I need.
It's a hefty requirement no doubt, but it's not unreasonable at all.
For a bookshelf it is.
You really need towers for that so you can use multiple bass drivers.
OP
- Thread Starter
- #579
kk
Can always ask him. Probably pushing it for a single speaker, but should be fine for the pair…
In my testing, the passive radiator is the limiting factor. This could be helped by used the dual Purifi PRs, but adds quite a bit to the cost.
Can always ask him. Probably pushing it for a single speaker, but should be fine for the pair…
In my testing, the passive radiator is the limiting factor. This could be helped by used the dual Purifi PRs, but adds quite a bit to the cost.
In my testing, the passive radiator is the limiting factor. This could be helped by used the dual Purifi PRs, but adds quite a bit to the cost.
My understanding was that the passive radiators worked below 100Hz right?
