War of the Worlds, The MiniDSP SHD vs Analog

Hi Juan:

Without MiniDSP they sound great.  I am trying the DSP route to see what if anything might be left on the table :

Ah, ok, I misunderstood what your issues were.  The biggest benefits of DSP IMHO are in the bass.  Clipping excess peaks, and raising the bass to preference. I wrote a little about this here:

https://speakermakersjourney.blogspot.com/2021/12/room-speakers-eq.html 

I have not replaced caps on the crossovers as I'm weary of messing things up. 

Upgrading existing caps is a waste of money when your speakers need a different crossover.  Not sure about what's been done for your models though.  Sounds like you have already found Danny's crossover mods.  Take a look at the impedance changes the new crossovers offer.

Question is, do I mess with the design?

if you get higher minimum impedances, absolutely.  These are notorious. 

@erik_squires Hello Erik and thanks for the detailed response.

Without MiniDSP they sound great.  I am trying the DSP route to see what if anything might be left on the table :

- from my speaker placement

- the room treatments 

- degradation of the speakers through time

- flaws on their design

I have not replaced caps on the crossovers as I'm weary of messing things up.  My restoration of the Xovers has been limited to resoldering and reattaching a couple of caps that had come loose (the components are hot glued and hang from the cover of the crossover boxes) and cleaning the pots.

I will get DATS3 to test impedance etc.  Sounds interesting and hopefully i can make sense of the measurements.

Regarding aftermarket crossovers, there are a couple of options out there:

- Bayer in Germany has a new version which I have read is superb.  I have spoken to Mr. Bayer about them (great resource BTW!)

- Danny at GR designed a crossover with some changes.  I have his measurements and they look really well.  I owe him a call; he is very open and offered to help if I wanted to do this

Question is, do I mess with the design?

! Juan

@ervikingo - Whenever I hear of people having issues with vintage Infinity speakers I always look to the measurements of the impedance curves first.

Infinity was many things but careful about crossover impedance was not one of them. There are legendary stories about finished speaker designs being hacked late in the product development stage and ending up a hot mess electronically, and this in turn can make a lot of amplfiiers measurably underperform in the frequency domain.

Per Stereophile measurements: these speakers have several 2 ohm valleys which can give a lot of amps trouble. First thing to do is to see if there are aftermarket crossover kits which fix the issue, and I know there are for some models. Second is to compare your frequency measurements to that of Stereophile to get some idea of how off you might be.

Another is to measure the impedance of each speaker and, again, compare them to the Stereophile charts. This will tell you quickly if your speakers have failures in the crossover or drivers. I like to use DATS by Dayton Audio, but you can also build a poor man’s impedance measurement using Room EQ Wizard. Google it.

Best,

Erik

Honored!  Will message you now!

@ervikingo , 

Message me and we will see if we can get it straightened out.

I got me a MiniDSP to try what it would do in my system with my IRS Beta.  Having many issues getting the software to do measurements (UMIK 1 and WIndows 11) I keep getting errors of s/n.

When I finally got it to get some readings the results are horrible.  Thus, I guess the measurements are causing the problem or I am doing something very wrong.

I have not found the FAQ on MiniDSP nor DIRAC to be of help.

Any leads on where to get some help?

@erik_squires , I do not know much about that. There are issues that have to be dealt with like content protection, but it would seem to me when you are trying to get a format established you want to bring everyone into it you can. It is certainly not an issue the 2 channel world is use to contending with and in reality they do not have to. For guys who use their 2 channel setup for theater like I do it can be a pain like if you are handed a TV box that only has an HDMI audio output. I'm sure there are adapters. The DEQX does not have an HDMI socket on it and unlike most other companies do not seem to have any interest in theater. Suits me. 

OP:  It is my impression, with very little evidence, that the HDMI licensing issues were a huge hurdle, even for companies like Meridian.  Probably had a very large entry fee. Theta's delay, and then essentially turning to an OEM HDMI board manufacturer is part of what makes me think this. 

@erik_squires , TacT audio imploded also. They were way ahead of their time, too far ahead. Their Theater processor also lacked HDMI. Had they stayed alive it would have been added. The remnants of TacT you know as Lyngdorf.

Time and processing power march on and the new DEQX has a 64 bit, floating point operating system with a signal to noise ratio of -140 dB. Clipping and volume issues will be things of the past. I expect the benefits to far outweigh any deficits. 

I am afraid that if I use a cheap miniDSP in my analog path I may not even know it is there, and then where would my cred as an audiophile go?? 😀

I will end adding to this discussion by saying that a very long time ago I had a Theta Casanova and it was a fabulous musical performer, as well as excellent home theater processor. It has the distinction of converting everything to digital, AFAIK there was no pure analog path. Still sounded really wonderful.

The slow-quitting of Theta Digital at the time, and failure to produce an HDMI product in time, or the Supernova was a real disappointment to me.

@fuzztone , I think you are probably right, but this is a very temporary setup for me and the goal was to spend as little as possible. If you can afford two high quality DACs by all means, go for it! 

I spent a few hours listening to a wide variety of music last night flipping Dirac Live in and out by remote. Dirac live tightens everything up. The image snaps into focus and the subwoofers disappear even though bass power improves. These changes are not remotely psychological. A pure analog person might say that if you got rid of all the DACs and switched to an analog crossover you can achieve even better results. I spent 20 years approaching the problem that way. I have had subwoofers since 1979. You will never get these results in total manually, never. I think everyone can be comfortable that any platform running Dirac Live will achieve great results. 

I prefer the Studio with a favorite DAC.

@erik_squires

 Then the question would be would substituting DACs improve the performance. There are two SPDIF outputs one for channels 1+2 the other for channels 2+3. It is a unique possibility. Would it get you to the performance of a Trinnov Amethyst or DEQX Pre 4 or 8? Two Benchmark DACs at $4000 for the pair plus $1500 for the SHD with UNIK2 for a total of $5500. 1/2 the price of the Trinnov. Not sure what the DEQX is going to cost yet. I use an outboard ADC for the phonograph so there are no other considerations for me but others with phono stages to digitize might be in for further expenses. It would be a very interesting experiment ,but I am already in for the DEQX hook line and sinker. This is as far as I am going to go with this. The SHD has already been resold. 

Where it is let down is in the quality of it's DACs which is, I suspect, the origin of the graininess I perceive.

Which is why I pointed out that it's a very good thing to have even if you don't use it full range, so your reply supports my main point.

@erik_squires , I have plenty of experience with JL Audio's subwoofers and crossovers. There is absolutely no comparison to digital crossovers and full frequency room correction. Even the diminutive MiniDSP wins that battle hands down in combination with Dirac Live which is a web based Room Correction protocol. Where it is let down is in the quality of it's DACs which is, I suspect, the origin of the graininess I perceive. 

For people with systems in the 10 to 30 thousand dollar price range, particularly if subwoofers are being used, the SHD is a real winner.  

Even without Dirac, miniDSP in line with a subwoofer can be a very effective, if not absolutey glorious combination.  It's certainly a lot less expensive than say, JL Audio's combined subs + room correction.

The auto measuring/control stuff I prefer to leave for home theater stuff, which really, what is included in a $2-$3k denon, onkyo etc, is good enough.

I want more manual control for music.

active crossover like the k231 (2 sub outs) from sublime acoustic (and there are others) lets me change up depending on what I am listening to, or even how I want to listen to it depending on how my day is going..

Just saying.. if you like to continually “adjust” things when listening to music, a dsp might not be the best answer.