I guess you could also put it that way. Basically, there is often something to be learned from what we don't totally agree with. These are what I call the diamonds. I have learned a lot from Earl even if I don't totally agree with everything he says. Lots of us want to develope better audio systems, there will never be a single way of doing so because the tradeoff considerations will be different. The important thing is that hopefully everyone enjoys the process and is happy when improvements do occur.
Hey Dr. Geddes, I started a thread in your page for your subs and room arrangement discussion. Just in case it isn't on your radar, my hope is that you could contribute when you have time.
Dr. Geddes,
I'm not sure if you have noticed the mini dsp boards company selling a universal dsp platform for use in audio. They not only have a few potentially useful programs ready to go , but claim to offer custom programs to fit specific needs. The price is low enough that just 2 of these units would be less than the Behringer, but offer the same abilities and flexibility. However, I think that custom programming could be developed with 3 units which would allow complete control of the main speakers, subwoofers, and correct routing of bass.
I'm not sure if you have noticed the mini dsp boards company selling a universal dsp platform for use in audio. They not only have a few potentially useful programs ready to go , but claim to offer custom programs to fit specific needs. The price is low enough that just 2 of these units would be less than the Behringer, but offer the same abilities and flexibility. However, I think that custom programming could be developed with 3 units which would allow complete control of the main speakers, subwoofers, and correct routing of bass.
I've seen them, but when all is said and done, power supply, enclosure, everything, the margins just arn't there. The Behringer still wins out.
It can be USB powered, and in my system, I have plenty of USB ports I could power it off of. Enclosure is an issue, but I had a bunch of Aluminum surplus enclosures. My main reason for considering it over the Behringer, which I do already have, is the need for more than the Behringer can offer. Specifically having the ability to input all the front 3 speakers and LFE input, so 4 inputs, and then direct bass from all channels to 6+ outputs, but with tailoring of 3 of those outputs. Plus, because I have and enjoy a tactile transducer in my system, I like to be able to feed it with it's own uniquely filtered signal. It would require two Behringer's to do this, at around 600 dollars total. It would require 2 minidsp devices at a total of around 200 dollars, and the rest of the parts I have. Even if I added a regulated power supply, it wouldn't be much more than 20-30 dollars. For me that's a big savings.
2 mini DSPs for 4 inputs? I don't know about you, but I ended up using a significant number of PEQ filters to get my system to behave. The mini DSPs are attractive in some respects, but I don't see the tunable PEQ capabilities being there today (could potentially be added through software, yes, but actual app available for download, no).
What are these mini DSP's you guys are talking about?
Sorry I'm a little late to the party... 😛
Sorry I'm a little late to the party... 😛
The DSP has 6 PEQ's per input, and 6 per output. This means that there would be a total of 24 PEQ filters at the input and 48 at the output. Exactly how many do you need? That is more than enough, and I believe more than the Behringer has.
MiniDSP
Here is a link to the unit.
I don't intend to use this above the transition frequency of the room, so I really can't imagine needing more than 72 eq filters in that range of dc to 200hz or so.
Is it a Buttkicker?
Is the signal particular to your installation or have you found a curve that seems to improve the effect of tactile transducers in general?
If the latter, I'd like to hear more.
I know this is OT, so maybe we can discuss it elsewhere; I searched on posts by you with "tactile" and didn't get anything.
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Ok, I didn't see that the last time I checked. Any reports on the analog sound quality? How about phase adjustments and HP/LP filters?
The principles of that company contacted me about working with them to develope a sub woofer control module. When we went through the business model it became clear that it could not compete with the Behringer on price. It would be more expensive, but could be custom tailored to the application. When all was said and done they decided that the risks were too high and the profit margins too low.
up to 7.5ms of delay per output and the typical first through 4th order crossover filters. They have a data sheet on their website which gives all the details. I mean, it's pretty basic, about the same as the Behringer, a few more limitations.
I haven't tried this device extensively yet, so I really can't speak to it's sound quality. My thought though was that it probably sounds fine at least compared with the behringer, but also has the advantage of a relatively simple circuit which could be easily upgraded.
It has 56 bit double precision processing, but only 48khz sampling. That's really fine though, and I've read Cubasse's discussion of these vs the 88 and 96hz filters, with the relative merit to the lower sampling frequency. Add's some audiophile fodder I suppose.
To answer Noah's question, I don't work any magic with my Buttkicker, but that is what I use. I play test tones through it to figure the frequencies it worked best at for giving that tactile sensation, and then inserted a substantial eq boost. I also have it setup right now with it's own much lower crossover frequency of around 60hz 4th order. My ULF subs are crossed higher right now, at around 80hz, and use a 2nd order filter. This just happened to measure flatest in my room, it's not necessarily better.
I wish the DSP could handle FIR filters more directly. They say you can port IIR filters directly over with certain external software, which may work, but if I could use the FIR filter and do my own programming, I have some idea's I want to try. I'd really like to try actively crossing over my Abbey's sometime, but would really need Dr. Geddes measuring ability and input to do it right, and then convert his techniques to optimized FIR filters with a better phase response (so I've read at least).
My ideal here would be a preamp like the Meridian's with digital outputs, then send each channel sets signal digitally to a DSP unit, and process it that way. It would need to have a volume control after the DSP's and that adds even more complication, but it would sound the best.
Was the intent to have this be an auto setup device? I mean, it can do what the Behringer does as is, so the only additional costs would be casework, power supply, and software. I could see doubling the current price, if not more, if they intended to create an auto-bass EQ module for multiple subs, and it probably would be a bit of a risk.
Having been down that road, my experince was that it ends up sounding the same. A lot of work and expense for no real perceivable improvement. My first speakers - about 40 years ago - had active crossovers. It was "cool". Now I just fine them a waste of money.
Hopefully we will see working automated setup routines built into upcoming AVRs. That's where calibration should be handled.
There are already capable platforms like the Emotiva UMC-1. Now they just need to figure out how to do it right.
Best, Markus
There are already capable platforms like the Emotiva UMC-1. Now they just need to figure out how to do it right.
Best, Markus
Yes, the intent was automatic.
What DIYs always seem to forget about if profit margin. There is almost none in the modules, but there would have to be some (usually 50% or more) in the final product to support all the development, etc. This is what killed it.
That small feat will only take another five years or so. Its all NIH at audio companies. When everyone is an expert, expertise is cheap. And you get what you pay for.
"Its all NIH at audio companies. When everyone is an expert, expertise is cheap. And you get what you pay for."
Interesting comment; my experience whilst running a development department was quite the opposite, real expertise was actually far to expensive. The royalties required by those that had actually worked out useful algorithms are so high as to make them prohibitive and small companies that couldn't negotiate with volume simply can't afford to use them.
So the only option was to invent in house or adapt the fairly basic options that came with the DSP decoder algorithms. On AVR products whith so many different parts of the design all competing for the available budget you can't really justify a $20 or more royalty for a premium set up algorithm when one that is acceptable to most customers comes with the decoder.
I guess it will take 5 years for todays leading algorithms to become equivalent to those included with the decoders. The NIH comment wasn't true where I worked, we spent alot of time and effort talking with many companies visiting teh AES conventions etc. (I paticularly remeber a French team that had a very clever algorithm for room equalisation but absolutely no idea how to use it) and in the end mostly they simply priced themselves out of the market. Probably for good economic reasons as it is as expensive to support a small company as it is a large one (and sometimes much more expensive as we were very fussy, whilst the likes of the Jap big names just wanted the logo on the front as far as I could tell)
You clearly have a very different viewpoint on this, I guess you have had some bad experiences from the other end. In the end the design has to make money and as you pointed out earlier, often a great idea is not economicaly viable because there simply arn't enough people who care and will buy it at its development cost.
Regards,
Andrew
Interesting comment; my experience whilst running a development department was quite the opposite, real expertise was actually far to expensive. The royalties required by those that had actually worked out useful algorithms are so high as to make them prohibitive and small companies that couldn't negotiate with volume simply can't afford to use them.
So the only option was to invent in house or adapt the fairly basic options that came with the DSP decoder algorithms. On AVR products whith so many different parts of the design all competing for the available budget you can't really justify a $20 or more royalty for a premium set up algorithm when one that is acceptable to most customers comes with the decoder.
I guess it will take 5 years for todays leading algorithms to become equivalent to those included with the decoders. The NIH comment wasn't true where I worked, we spent alot of time and effort talking with many companies visiting teh AES conventions etc. (I paticularly remeber a French team that had a very clever algorithm for room equalisation but absolutely no idea how to use it) and in the end mostly they simply priced themselves out of the market. Probably for good economic reasons as it is as expensive to support a small company as it is a large one (and sometimes much more expensive as we were very fussy, whilst the likes of the Jap big names just wanted the logo on the front as far as I could tell)
You clearly have a very different viewpoint on this, I guess you have had some bad experiences from the other end. In the end the design has to make money and as you pointed out earlier, often a great idea is not economicaly viable because there simply arn't enough people who care and will buy it at its development cost.
Regards,
Andrew
Say Earl, on the subject of grills for your speakers, how about ones using the reticulated foam, say 1/2" thick with a radiused edge?
I think that would clean up the looks a lot.
To go a step further, a single piece of foam that covers both the woofer and WG aperture, in a racetrack shape, i.e., fully radiused at top and bottom.
I think that would clean up the looks a lot.
To go a step further, a single piece of foam that covers both the woofer and WG aperture, in a racetrack shape, i.e., fully radiused at top and bottom.
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