Custom MiniDSP 2x4 Balanced build

EndersShadow

I got it booted up and after a small scare (had to reload in firmware since there is no battery to store settings) its up and running

My second Crown XLS2000 also arrived today so I now have everything *almost* done.

I'm gonna get a set of wireworld Equinox XLR's from @DSkip, and then try to find a set of decent RCA sub cables and I should be golden connection wise.

Then all thats left is to start the EQ process.

@erniejade I have the input sensitivity @2VRMS and the output @4VRMS so its setup like this:

Denon - RCA - 2VRMS Input on MiniDSP - 4VRMS Output on MiniDSP - Crown XLS2000

Is that right, or should I adjust the output down to 2VRMS on the output as well

The Crown Spec's list this for the sensitivity: 1.4Vrms (for full rated power at 4 ohms)

erniejade

Are you running them in bridge in crossover mode or full range and letting the dsp do that part? Do you have the limiters engaged?

On the sensivity, if the volume is loud enough and its not distorting at lower volume ( overdriving the input) then I wouldn't worry too much about it. If you are getting any kind of distortion when its at lower volume, kick it down to 2.

EndersShadow

erniejade wrote: »

Are you running them in bridge in crossover mode or full range and letting the dsp do that part? Do you have the limiters engaged?

They are Bridge, Full Range and Limiters are on. MiniDSP is only adding a 10hz Highpass for now.

I'm letting the AVR handle the crossover.

EndersShadow

I thought I'd update this a bit. I still haven't dug super far into the software yet, but I've added what amounts to some "bling" to the unit. I wont get into a debate on if these make a audible or measurable difference, but they help with my personal OCD (which this project was all about resolving anyway).

In the simple category I purchased a 10 foot USB 2.0 USB-A to USB-A cable, so I could, you know program the unit. I realized I didn't have one initially so to program it I had to pop the top, disconnect the cable we added, use the cable MiniDSP sent me, program it, and then put it al back together... Big PITA lol. Thankfully this arrived today, so MAKE SURE YOU HAVE ONE, assuming you go with the USB-A side on the connector facing out, instead of the USB-B side (which would let you use a standard printer cable to program).

As to the actual "Bling", I'd previously purchased a set of 50 of RCA noise stopper plugs from Apollo AV. They are cheaper than the Audioquest or Cardas versions and IIRC they are actually who makes those, so these are just their version which your paying manufacture cost without the markup for a name.

They also sell XLR versions, so I purchased some of their male and female versions to fill in the unused holes on the MiniDSP & the Crowns (since they are bridged).

They sell these on eBay (duh thats where the links are from), as well as Amazon.

I also stumbled into a pair of Wireworld Series 6 Equinox 1.5m XLR cables at a decent price (thanks @DSkip), so I snatched those up as well. I am still going to need to get a decent set of RCA cables for the AVR -> MiniDSP connection and I'm looking at either the Audioquest Black Thunder II or BlueJeansCable LC-1's. I've run both before and like both.

The LC-1's spec's (design page here) make it an interesting cable, both for subs and also for mains, and its very cost effective. Is it 20 cents a cable and Monoprice, umm.... no. I Is it 200 dollars a set, no. I also liked the terminations as they were snug enough to not pull off easy, but also didnt exhibit the death grip I've found with some of the Monoprice RCA's in the past (they pulled the ground shield off 3 different inputs on one of my amps). A set of 6 footers would run me about 50 bucks plus a couple in shipping to my door.

The Black Thunder cable I ran was another well built cable, price was decent (I got it used) and I felt the terminations were quite nice and easy to connect and disconnect. I wont get into what audible changes I feel it made as then we get into a cable debate and get way too off topic. However buying new, a set of 1.5 or 2m of these cables runs into the 160 dollar range, which is a bit pricey for... you know... sub cables lol...

**Slightly Off Topic** For those of you looking for some decent speaker cables at a very affordable price, I do suggest BlueJeansCables speaker cables. I really like they way they sonically weld the cables so you NEVER need to worry about the termination coming loose, or pulling out if you tug too hard on them. And for the price they aren't that bad if you dont want to deal with making your own DIY cables and terminating them. Assuming of course you dont need like 100 foot runs. Front 3 speakers with the AVR nearby would be fairly cheap IMHO. Surround cables could get pricey so those may be worth DIY'ing. I also like them because the Belden cable they buy comes from good old Richmond Indiana , so I'm supporting a local Hoosier company.

sgmsmg

In case you didn't see someone just posted these. Probably easier than what I messaged you about.

https://www.audiogon.com/listings/interconnects-audioquest-black-mamba-ii-audio-interconnect-cables-2017-04-19-cables-92399-yucaipa-ca

EndersShadow

sgmsmg wrote: »

In case you didn't see someone just posted these. Probably easier than what I messaged you about.

https://www.audiogon.com/listings/interconnects-audioquest-black-mamba-ii-audio-interconnect-cables-2017-04-19-cables-92399-yucaipa-ca

Thanks. I'm partial to the Black Thunder over the Black Mamba.... I'm a cable snob, what can I say lol...

And a broke one at that, so the upgrade will need to wait a bit.

erniejade

EndersShadow wrote: »

Thanks. I'm partial to the Black Thunder over the Black Mamba.... .

So many jokes can be said right here.

EndersShadow

erniejade wrote: »

EndersShadow wrote: »

Thanks. I'm partial to the Black Thunder over the Black Mamba.... .

So many jokes can be said right here.

So many that none need to be lol.....

But yes, I walked right into that one....

EndersShadow

A friend turned me onto this video regarding the RCA/XLR caps I felt worth posting here given it shows some quick measurements of them

https://youtu.be/KFciL0qjqu0

EndersShadow

I think I am finally happy with how things sound bass wise...

I've got a Denon X4100 and 2 subs. A Dayton Ultimax 18 in a 4 cubic foot box, and 4 Infinity 1262's wired as a single 4 ohm load in a box about 6 cubic feet total. Each sub as its own bridged Crown XLS2000 to drive it, and both Crowns are wired to a dedicated 15 amp breaker (might be 20 but think its 15). The Dayton sub is in the right front corner and the infinities are at the rear left along the wall with the stairs (see pics below).







The Infinity box is located below this sofa table I built



Here is what I did.

1. Connect the Sub1 and Sub 2 outputs from the Denon to the 2 inputs on the MiniDSP, and connect a single sub to each set of output on the MiniDSP
2. Run XT32
3. Set Xover on fronts to 250, LFE to 250
4. In the Denon adjust the distance settings between the subs to ensure they are summing constructively. In my case this meant adding case 4 feet to the distance for my Dayton sub in the corner
5. Measure the combined sub response across all three main seats via REW
6. Use REW to generate a average response
7. Use the EQ feature in REW to generate filters to put in the MiniDSP to even out response. Export those filters to a file.
8. Import filters into MiniDSP
9. Re-Measure all 3 seating locations to see if they are fairly close in response (they were)
10. Add in a Shelf filter to boost response below 30hz by 12db* (which is a lot BUT well...... its me....)
**If its too much, I can always tweak it later without having to redo much besides connect my laptop to the Mini and program it, which is REALLY REALLY NICE
11. Re-Measure to ensure all 3 seats response increased right
12. Re-Engage 80hz crossover on Mains
13. Measure response (looks pretty decent)
**At this point I tested a couple movies and was disappointed in the response.
14. I added a LFE boost to the signal of 9db in the Denon
**At this point I rested a few movies and was MUCH HAPPIER with the response. And I'm still not getting above 3 lights on the XLS so I think I'm ok.......

REW graphs

After redoing XT32 I took measurements at my 3 main LP's. I increased the sub crossover to 250hz and the LFE to 250. Here are the results across all three seats:



Using the middle seat I measured a bunch of different sub distances and settled on 20.9 as it was the most constructive. Adding additional feet didn't make much of a difference and subtracting 2 feet from the Dayton really jacked up the response. I have measurements not shown in this picture.



Using that distance measuring across all three seats:



I averaged that response and used it in REW to create the EQ filters to add to the MiniDSP.
I then added a initial low shelf filter via the MiniDSP to the response and got this...



From there I remeasured the front three seats with the Left Speaker + Sub and Right Speaker + Sub for a total of 6 measurements. Averaging those responses by speaker...



I'm was fairly happy with that graph.... however in reality it didnt sound good, so I added 9db of boost in the Denon... I am MUCH happier than that.

I was asked in another thread to see what the THD of my setup was on my graphs as the boost I am applying is quite high (21db lol).

Left Speaker:

THD @ 20hz shows 0.893%



Right Speaker:

THD @ 20hz shows 1%



All my measurements were with the volume on my Denon at 50 which is normally about as loud as we get. The MAX volume my Denon X4100 is 98 (just checked). It starts at 0 and increases in incremental of .5. I have it limited to 80 so if the kids get ahold of the volume they won't kill everything by going all the way up.

Given that 98 is the max and I get to 70-75 max when listening even loud, I'd guess that's why my distortion is so low, because I'm not really listening that loud or sending a large enough signal to clip my the MiniDSP inputs or the Crowns inputs from the MjniDSP. THD will likely skyrocket the higher the volume gets I'd guess.

Also these measurements are NOT showing the Denon boost. I dont have time to redo those measurements right now, but might to sneak some more later this week.

I'm kinda a bass head.... ya know but most folks knew that about me already... aint that right @daboyz

EndersShadow

I should mention that I am still not 100% done. I'm thinking I need to tweak the lower end a bit more and get those measurements with the Denon boost enabled. It may actually be too much because during TV the past day or so I've had to turn the subs off to be able to not feel like its techno TV lol....

lightman1

Dan.....stop with the graphs. You have three dedicated 20A circuits in the living room. I know....I ran them point to point.

There are times that "bass" is an overbearing aspect of the movie experience.
The KC HT crawl exposed me to the dumbest LF response.
I can go on for hours about this and that.
But I can't here on the open forum.........

ZLTFUL

You can't teach these younguns Russ.

EndersShadow

ZLTFUL wrote: »

You can't teach these younguns Russ.

Says the guy with 6 18' subs and like 50 million channels of amplification lol.....

ZLTFUL

It's only 23 channels of amplification thank you very much.

EndersShadow

ZLTFUL wrote: »

It's only 23 channels of amplification thank you very much.

I rest my case

txcoastal1

EndersShadow wrote: »

ZLTFUL wrote: »

It's only 23 channels of amplification thank you very much.

I rest my case

And the ratio speakers to subs Ryan has vs the ratio you have??????

Please include sq footage

#micdrop

txcoastal1

txcoastal1 wrote: »

lightman1 wrote: »

Thorton wrote: »

Enders, so you have 1 - 18" and a box with 4 - 12". What is the length, width and height of the room? Just curious.

Small enough for a bass head like Dan to pressurize with stupid power to woofer ratio and still not be happy.

Worth repeating

What do you expect, he started in car audio where they put 4-12" subs in 10 cubic feet of space, and still wanted more

EndersShadow

txcoastal1 wrote: »

EndersShadow wrote: »

ZLTFUL wrote: »

It's only 23 channels of amplification thank you very much.

I rest my case

And the ratio speakers to subs Ryan has vs the ratio you have??????

Please include sq footage

#micdrop

I have 4 12s but it's in one box acting as a single sub. I have an additional 18" sub so it's really only a 5.2 system.

Ryan is shooting for a 11.4.6 system IIRC lol....

My square footage is like 1900 square feet as the family room is open to the entire first floor....

His theater room is gonna be like 16x20 or something lol...

So he's got more speakers, more subs and less square footage to fill....

EndersShadow

txcoastal1 wrote: »

txcoastal1 wrote: »

lightman1 wrote: »

Thorton wrote: »

Enders, so you have 1 - 18" and a box with 4 - 12". What is the length, width and height of the room? Just curious.

Small enough for a bass head like Dan to pressurize with stupid power to woofer ratio and still not be happy.

Worth repeating

What do you expect, he started in car audio where they put 4-12" subs in 10 cubic feet of space, and still wanted more

It was only a single 10 in a ported box with 1000 watts and 2 pair of Polk db6501 components with 125 watts x 4

msg

Dan, wow, what an involved project. I barely understand what you're doing here much past ocd and making big black boxes that go boom. So many neat elements in its development. Enjoying the little refinements like the enclosure to keep everything neat. That wiring work looks great. A shame it's all sealed up! And noise caps. How long have you been working on this, including the early stages of research? Looks like a tremendous amount of research and learning over time.

What did you use for machining the holes for the jacks on the enclosure? That turned out great.

What did you use to draft your floor plan? That looks handy.

Great work so far. Even though I don't understand it all, your process writeup is informative and relaxed; nice read. Subscribed.

EndersShadow

msg wrote: »

How long have you been working on this, including the early stages of research? Looks like a tremendous amount of research and learning over time.

Well the research around the building of the enclosure was about 3-4 months I think, however I had that AVSForum example I was already aware of to get somewhat of an idea what parts I'd need. Deciding which XLR jacks/etc was actually more of a pain. I had to decide between cheaping out on parts overall to keep cost low (and then hating myself later because of my OCD), or spending a little more per item to get a higher quality part, which is what I did. I also had just come off building some sub boxes with Nuetrick connectors (which I know folks here love and I see why), and was very happy with them, so it made it easier. Also I tried to limit the number of suppliers I had to buy from to help lower shipping costs.

The enclosure was the actual hardest part to track down what would work, and even then if I had gone with a 2U case it may have been a bit easier for Rich to install a couple things. But I couldn't have known that at the time......

msg wrote: »

What did you use for machining the holes for the jacks on the enclosure? That turned out great.

No clue, that was all Rich........

msg wrote: »

What did you use to draft your floor plan? That looks handy.

Floorplan was created with MS Visio. Because I have to know how to use it for work, and have it on my work computer, when testing or trying new things to stay fresh with the program I try to base them around something I could use for myself.

Mainly we use it for process mapping and process design, but I on occasion need to use it for accident reconstruction diagrams and things so I try to play around with different types of documents within it often.

Like wiring diagrams of my setups and whatnot (see below really old diagrams).

msg wrote: »

Even though I don't understand it all, your process writeup is informative and relaxed; nice read. Subscribed.

To simply it, I am basically using the program to help me time align the subs to ensure they are working together as best they can as a team. I am then using the program to measure my rooms reaction to them and create a custom EQ that results in a fairly flat response.

Then I take that flat response and add a because a flat response isnt actually what you really want, I add a low shelf boost to slowly increase the SPL below 25hz. I also use this to help fix the fact that because my subs are sealed they start to roll off around I think 30hz...



The overall goal is that my bass across my main seating area is even no matter what seat you sit in, and is able to be heard/felt much better and is missing as many dips and peaks in response as possible.

SCompRacer

Nice work Dan! I like the graphs. I also like your approach of mounting it in enclosure instead of dongle adapters hanging off the box. I may build one for my lower Hz enhancement, or subs, in the two channel system.

msg wrote: »

What did you use for machining the holes for the jacks on the enclosure? That turned out great.

Thanks! A step drill mounted in drill press with lubricant. I also use duct tape to protect finish as a stray burr caught on bit can scratch face.

Like this one.

Thorton

EndersShadow wrote: »

From there I remeasured the front three seats with the Left Speaker + Sub and Right Speaker + Sub for a total of 6 measurements. Averaging those responses by speaker...



I'm was fairly happy with that graph.... however in reality it didnt sound good, so I added 9db of boost in the Denon... I am MUCH happier than that.

Also these measurements are NOT showing the Denon boost. I dont have time to redo those measurements right now, but might to sneak some more later this week.

Lookin good so far!!!

So you were about 13 dB (@20 hz) up from the mains and added another 9 dB to the subs. Holy Smolly, you do love your BASS. When you do have a chance, let's see the final full range frequency response. Also, can you show us a waterfall graph of the subs.

Time to crank it up....and in your case.....break some windows!!!!!!!!!!!!

EndersShadow

Thorton wrote: »

So you were about 13 dB (@20 hz) up from the mains and added another 9 dB to the subs. Holy Smolly, you do love your BASS. When you do have a chance, let's see the final full range frequency response. Also, can you show us a waterfall graph of the subs.

Its a bit more convuluted than that due to the fact my levels for the subs in the Denon isnt at 0, and there is EQ being applied as well within the Mini to bring down some levels.....

So I'm not sure its truly 9 + 12, but more like 9 + 12 + -7 which is more like a 14db increase, which is still quite a bit but also less than that closer to 25hz.

Here are the settings in the Denon.

Setup/Audio/Subwoofer Level Adjust/On/ Subwoofer Level 1 + 9db, Subwoofer Level 2 + 9db
Setup/Speakers/Subwoofer 1 -7.0 db, Subwoofer 2 -5.0db

Here are my settings in the MiniDSP

Parametric EQ (showing pic as I didn't have time to spend writing down all the biquad stuff):



Crossover: Highpass Filter Settings - Cut off Frequency 10 | Filter Type BW 24db/oct


Parametric EQ (Output 1, 2, 3, 4) - Low Shelf Filter | Frequency 30 | Gain 12 | Q .5

EndersShadow

I thought the thread was worth fixing since photobuckets ransom demand killed it. Attached is a PDF file containing the thread and all associated pictures.

Enjoy.

EndersShadow

Bumping this thread as I found a new cool piece that lets you connect wireless to control and tweak the settings.

The WI-DG is a Wifi/Ethernet to USB bridge that is pre-configured for Plug&Play discovery and control over IP networks. The Wi-DG is a tiny adaptor that interfaces to the USB port of a miniDSP hardware unit and acts as a Wi-Fi to USB bridge. Supported miniDSP plugins transparently detect and communicate with the miniDSP via the Wi-DG, enabling control and configuration over the network. Normally, the computer running the appropriate miniDSP plugin is connected directly to the miniDSP hardware unit using a USB cable. With the Wi-DG, however, the computer connects using Wi-Fi in 2 possible modes of operations: Station mode or Access Point mode. Please check out the user manual for more details.

The WI-DG also supports Amazon Alexa voice control via our free Alexa Skill as described in this application note. Yet another way to easily control your audio.

I'm seeing if its possible to accommodate the WI-DF inside the custom chassis as well as replacing the wallwart powersupply with the better power supply board they also sell, which could allow me to use a 12v trigger to turn this on and off.......

The miniDC isolator is a tiny board allowing a perfect system integration with power on/off of your DSP and amplifier system. Based on a DC-DC isolated converter and delay circuit, it allows you remote turn ON/OFF in the correct order. This board is especially recommended for car audio application to allow complete isolation of the alternator noise. Compatible with miniDSP 2x4, 2x4 Balanced.

I think if I add those two pieces then I will have both maxed out all the available internal space, as well as the functionality of the piece for a few more years

EndersShadow

I also may go crazy and see if there is a way to set things up where a single 12v trigger turns the Mini on/off and also lets me trigger all 4 of my external amps as well..... but not sure there is enough room to do that, both internally, and on the chassis for the plugs