There are several other proven options available if you are ok to separate the amps and processors: BSS BLU, openDRC, DCX2496, etc.Originally Posted by alskinner
There are several other proven options available if you are ok to separate the amps and processors: BSS BLU, openDRC, DCX2496, etc.
I appreciate all your support. It has given me a lot to think about. I do have several amps. It will probably be a while before I actually build a system. I have the 2216s but still need the horns and adapters. My main goal right now is to get the parts before they are no longer available.
Right now I'm building a test stand for my 2441s and 2311 horns to see if it's worth while to integrate them in the 4344s. The shorter horns will better line up the 2235 and 2122 magnets and help remove the delay of using 2307 horn. It will be interesting to hear the difference.
Another project that is in the works is a DD55000 clone. I have pair of NOS E145s, 077s, and 2425hs but only have one 4660 horn. Not sure when and if I will find another one.
Regards
AL
Attached are some pictures of the variation of the M2 I came up with. The cabinet is 46.5" H x 19.5" W x 13" D. Internal dimensions are 45"H x 18.25"W x 11.5"D which comes out to 5.46 cubic feet. I believe the M2 has an internal measurement of around 5.2 cubic feet. I did use 2" x 3 " internal bracing so that would bring down the cubic feet slightly. I used 3" Precision ports with a 8.4" length for a tuning frequency of 27hz. There is a 3/4" thick panel around the port area. I know some people curved it but I thought I would try it straight to see what the effect would be. The grill is a solid piece of 3/4 inch plywood with a 16.75" hole cut so that it fits over the woofer. This will also change the way the woofer acts and I'll need to take measurements to see what the effect it has. It also has the M2 crossover.
I bought I MiniDSP 2x4HD and hooked it up to a Threshold Stasis II and a Sunn SPL 9000 amp and made some basic xovers to get sound and not blow anything up. I now have a rudimentary understanding of how the DSP works so now the fun begins as I have a lot to learn and the ability to measure it is crucial to success. Will post more as the project progresses.
If this needs to be moved to a different area of the forum please do.
Regards
AL
Cool!
I think you might want to consider the miniDSP Flex unit to take care of your needs. By all reports the version with Dirac Live is technically excellent. I bought a variant that I use as an A to D for an all digital system and am impressed with the quality. Not sure about the interface and learning curve on adjusting the settings as I haven't needed to dig into that level, but many other DIYers have had great success so you should be fine.
With the Flex version you should be able to take the info POS has posted on the M2 curves and get these dialed in to perfection and can use Dirac Live to correct any room issues. I believe the 2X4HD will only give you basic crossover functionality.
Widget
Thanks Widget
I bought the 2x4hd as a learning tool and as I reach the limits of it's capability plan to upgrade to either a BSS or the Flex. Being able to import the M2 files would defiantly save a bunch of time and frustration, but even those files may need to be tweaked due to my cabinet design. This is my first foray into DSP so I have got a lot to learn. I do have patience as it took me years to get the 4344s to sound like I wanted them to.
I also want to get new amplification as what I have is at least 30 years old. Although the Threshold has been a reliable workhorse there is better technology out there. I'm leaning toward Parasound right now
Nice work. Enjoy, they are fantastic but may require some attention to the room as they are 100 by 100 in coverage.
Let the fun begin!
The solution to the problem changes the problem.
-And always remember that all of your equipment was made by the lowest bidder
The Flex unit is an exciting offering. Do you know, or does anyone else know, whether "both sets" of coefficients from POS will work on the Flex unit. The first set is IIR coefficients of standard filters and their associated phase shifts. There is also did a second set using FIR filters which can "undo" the phase shifts (IOW, a flatter phase spectrum) but with a penalty of increased computational resources. When POS did this using using OpenDRC-DI (which has both IIR and FIR filers), then TWO units were required due to the increased computational load. My question is whether a SINGLE Flex unit (which can do both IIR and FIR filters) has sufficient horsepower to do all four output filters using FIR filtering. If the answer is complicated, then I can start a fresh thread and not corrupt this one.
I have not used any of the miniDSP Flex's features beyond using it as a simple A to D so I haven't researched the capabilities and limitations. In comparison with the BSS offerings, it is a more modern design than the BSS units I am familiar with so it may offer higher performance... which may or may not be audible.
Widget
They look really good! Have fun, curious what your comparison will be to the 4344's. I really like mine and the 100 X 100 works just fine for me.
Rob
"I could be arguing in my spare time"
Dirac Live
At first I had trouble keeping a connection to the Dirac server due to my ancient computer and operating system. I bought a new one, loaded 32 GB of ram and the connection was steady as a rock.
I then loaded the equalization and crossover settings provided by POS in the output section as Dirac will not allow you to load equalization in the input section in the minidsp. Using a minidsp UMIK-1 mic as recommended by Dirac I proceeded to the volume calibration settings setting the output and mic settings. If these settings are too low Dirac will let you know. I then went to measurement section and chose the 13 position measurements which record data from the front, back and both sides of the listening position. It is important that these measurements are equal for both sides of the measured position and room needs to be as quiet as possible. After that I went to the filter design section where you can accept the preliminary settings or customize them by the use of shelving and/or individual equalizer control points. You can then export the project to a slot on the MiniDsp. These settings can be edited at any time.
Upon playing music using Dirac I noticed a great reduction in room resonances without sacrificing bass response. Instruments and voices had a greater degree of separation with a spatial quality in the music. I verified this by toggling between the regular Flex module and Dirac. Two of the recordings I used was The Who's, Eyesight to the Blind from the album Tommy. Keith Moon's drumming and crash cymbals sounded more life like. The other recording was Pink Floyd's Pigs (three different ones) from the album Animals(2018 remix). The spatial quality was excellent with David Gilmour's guitar more life like. All music sounds better but well recorded material stands out.
The system is by no means perfect but it is deeply satisfying. The next project is treating the room itself. My listening space is 12'x16' with a carpeted floor and double window. I plan to put drapes over the windows and then get some bass traps and acoustic panel.
At some point I plan on purchasing a MiniDsp Flex eight which will allow me to try DSP on the L300s.
Regards
Al
Below are some snapshots of the results using Dirac.
That is really cool.
Thankyou for posting your progress. The detail of the procedure was really interesting.
Thanks Ian.
I forgot to mention is the default results in Dirac use are based on the Harman curve, which are quite good. As stated above the results can be modified by using the shelving and/or equalization within Dirac to taste. I am using version 3.65.
The M2 project so far has been one of the most rewarding and at times the most frustrating. It caused me to do tons of research in this forum and all around the internet. I knew that I would not be able to create a true M2 clone as I did not have the ports or the ability to do a curved panel at that time. So I compromised on a design that would match the dimensions as close as possible. Then starts the frustrating part. I knew I did not want to spend the money for the Crown amps that are used in the M2 implementation. I finally decided on a Minidsp 2x4 hooked everything up and loaded the equalization and crossover settings. One thing the Minidsp does not have is 36db Linkwitz-Riley crossover selection but has a 36db Butterworth. So I had to learn about biquads and created the Linkwitz-Riley. Hooked up everything and it sounded like crap. So I put my ear up to the high frequency driver and found there wasn't enough volume. Turned out that the Threshold takes more input voltage to reach maximum volume. Increased the high frequency gain in minidsp and I actually had music. I then decided to replace my aging amplifiers and bought the Parasounds and upgraded to the minidsp flex with Dirac.
As others have pointed out before a two way system is harder to implement correctly than a three way. I am well satisfied with the results, but understand that with more tweaks and room treatment it can be made even better.
I know I don't say it enough but I appreciate the guidance and comments on this outstanding forum.
Regards
Al
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