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Tutorial: Dual sub integration using the MiniDSP - Page 4

post #91 of 139
Thanks for the great tutorial! Just ordered my Mini DSP and can't wait to get it! smile.gif
post #92 of 139
Thread Starter 
Quote:
Originally Posted by Spanglo View Post

I only played around with boost below 20Hz, and settled on that gain setting because anything higher produced too many rattles and creaks. When I had the gain maxed, every boundary shook violently, and I could hear dishes in the kitchen cabinets and bottles of alcohol on top of my fridge clanking together. eek.gif

It's working as intended then biggrin.gif

It also look like your subs can keep up! I guess that was with the dual 18", not the single SB12 wink.gif
post #93 of 139
Quote:
Originally Posted by neutro View Post

That's awesome Spanglo, thanks for the details. You've got great results. It looks like REW didn't try EQing below 20 Hz -- did you specifically prevent it from doing so?
I don't have pics but you have basically two ways of powering the MiniDSP. First is through USB (connected either to a computer with a powered USB port, or to a USB charger e.g. for smartphones and tablets). The second way is to find a wall-wart type power supply (the kind used by small appliances such as wireless phone bases, routers, etc.). Almost any of those will work as the MiniDSP has an internal power regulator. It can accept from 5V to 24V DC I think. The tricky part is that you have to cut the connector and strip the wires. You have to find the polarity of the wires (typically the wire with a white line is +) and screw them in place in the Phoenix connector block. Using the wrong polarity may fry the MiniDSP... But once you're sure of your shot, well you've got an independent power supply for the MiniDSP. If you don't have a power supply in your old stuff box, I guess you can buy one for a few bucks in your nearest electronic store.

I was just a little worried about the unit having enough power using a USB power supply. I read somewhere about it a long while back and can't find the post. I am a little apprehensive about stripping wires. But I guess I can give it a shot.
post #94 of 139
Yes, just boosting the 18's, which apparently have ample headroom. The SB12 as I'm sure you're aware is limited around 20Hz, so no point applying boost to that sub.

Time to sit back and enjoy. Watched The Conjuring last night... which delivered some great LFE's and was entertaining as well.
post #95 of 139
Thread Starter 
Quote:
Originally Posted by Toymachyne View Post

I was just a little worried about the unit having enough power using a USB power supply. I read somewhere about it a long while back and can't find the post. I am a little apprehensive about stripping wires. But I guess I can give it a shot.

A powered USB port will provide enough power for the MiniDSP: it's really not power hungry at all, working only with line-level voltages. It's certainly the safest way to use it; the only problem being that you have to disconnect it (hence shutting it off) before plugging it in a laptop or PC (powering it back on) in order to fiddle with the plugin. Spanglo's solution, i.e. powering the MiniDSP by connecting it to the USB port of an always-on HTPC, is a great one in that regard.

If you have any doubt concerning wire polarity with a DC power supply, of course a multimeter will be your best friend.
Quote:
Originally Posted by Spanglo View Post

Yes, just boosting the 18's, which apparently have ample headroom. The SB12 as I'm sure you're aware is limited around 20Hz, so no point applying boost to that sub.

Well for any sub used below its limits, assuming a flat EQ, you can trade off output for extension. This is particularly true for sealed subs such as the SB12 (and your 18's I assume). While the DSP in the SB12 already boosts the low-end to provide a flat output down to about 24 Hz, I was able to further boost the low end using a BFD so that it was flat down to about 20 Hz, albeit only at moderate volume. At higher volume, the limiter kicked in and the SPL at 20 Hz could not follow.

That's why I asked about EQing your subs below 20 Hz. If you have ample headroom as it seems, you can try using the MiniDSP to EQ them flat down to... dunno, maybe 15 Hz? I guess you'd have to tell REW to EQ the 15-80 Hz range (assuming 80 Hz is your crossover) instead of the default 20-80 Hz.

In some way though, the shelf filter boost already is compensating for at least part of the sub roll-off. You're thus already performing the trade-off outlined above. Is your second measurement above (with EQ) with or without the low-pass shelf filter boost?
post #96 of 139
Yes both measurements were with low boost.

Flat to below 20Hz had too much rumble for my room. I had to dial down the boost to a level that didn't rattle everything.
post #97 of 139
Quote:
Originally Posted by neutro View Post

A powered USB port will provide enough power for the MiniDSP: it's really not power hungry at all, working only with line-level voltages. It's certainly the safest way to use it; the only problem being that you have to disconnect it (hence shutting it off) before plugging it in a laptop or PC (powering it back on) in order to fiddle with the plugin. Spanglo's solution, i.e. powering the MiniDSP by connecting it to the USB port of an always-on HTPC, is a great one in that regard.

If you have any doubt concerning wire polarity with a DC power supply, of course a multimeter will be your best friend.
Well for any sub used below its limits, assuming a flat EQ, you can trade off output for extension. This is particularly true for sealed subs such as the SB12 (and your 18's I assume). While the DSP in the SB12 already boosts the low-end to provide a flat output down to about 24 Hz, I was able to further boost the low end using a BFD so that it was flat down to about 20 Hz, albeit only at moderate volume. At higher volume, the limiter kicked in and the SPL at 20 Hz could not follow.

That's why I asked about EQing your subs below 20 Hz. If you have ample headroom as it seems, you can try using the MiniDSP to EQ them flat down to... dunno, maybe 15 Hz? I guess you'd have to tell REW to EQ the 15-80 Hz range (assuming 80 Hz is your crossover) instead of the default 20-80 Hz.

In some way though, the shelf filter boost already is compensating for at least part of the sub roll-off. You're thus already performing the trade-off outlined above. Is your second measurement above (with EQ) with or without the low-pass shelf filter boost?

Unplugging it doesn't do anything to the settings does it? I'm thinking I might go this route for my 4xHO setup.
post #98 of 139
Thread Starter 
Quote:
Originally Posted by Spanglo View Post

Yes both measurements were with low boost.

Flat to below 20Hz had too much rumble for my room. I had to dial down the boost to a level that didn't rattle everything.

Yeah some content below 20 Hz can reveal much about a house's construction smile.gif The infamous Server Room scene in Pulse (found in the above-mentioned Reference 2 Demo BD by the way) makes venting ducts below my living room rattle a lot. I just interpreted that as a sign I was in the right direction biggrin.gif

Good to know you can push your setup as far as your house will allow in any case tongue.gif

Quote:
Originally Posted by Toymachyne View Post

Unplugging it doesn't do anything to the settings does it? I'm thinking I might go this route for my 4xHO setup.

No, it doesn't change any setting. The only drawback is that it will temporarily cut the signal to your subs if your setup is currently playing. The sub will resume playing as soon as you plug the USB port back on. I have not experienced loud thumps (e.g. like when you unplug or plug the sub cable while the sub is on) while doing so, but that fortunate situation may not be universal.
post #99 of 139
Love that server room scene. I've downloaded most if not all the bass demo discs avail, and that scene is a favorite of mine too.

For music I like to demo this mix that has nice house basslines throughout: http://soundcloud.com/mirrorpop/mirrorpoptease001
post #100 of 139
Thread Starter 
Quote:
Originally Posted by Spanglo View Post

Love that server room scene.

Well it's no wonder the original blu-ray has a warning sticker on it saying you could damage your gear. The movie itself I've not seen (and with a Rotten Tomatoes rating of 10%, I can safely say I'll skip it). That's the beauty of those demo discs. Anyway, that scene sure is a great way to find sources of rattling.
Quote:
For music I like to demo this mix that has nice house basslines throughout: http://soundcloud.com/mirrorpop/mirrorpoptease001

I'll have to check that out tonight (work firewall blocks soundcloud it seems). I love good basslines (of course), but finding interesting music with subsonic (or near-subsonic) content is not easy. Of course, "Bass, I Love You" is a classic and a great test for sub setups, but let's just say it's not really a masterpiece biggrin.gif Dubstep and drum'n'bass typically have lots of great bass too, but most wub-wub bass patterns become old fast. Still, I've managed to find a few gems in the genre.
post #101 of 139
Quote:
Originally Posted by neutro View Post

Well it's no wonder the original blu-ray has a warning sticker on it saying you could damage your gear. The movie itself I've not seen (and with a Rotten Tomatoes rating of 10%, I can safely say I'll skip it). That's the beauty of those demo discs. Anyway, that scene sure is a great way to find sources of rattling.
I'll have to check that out tonight (work firewall blocks soundcloud it seems). I love good basslines (of course), but finding interesting music with subsonic (or near-subsonic) content is not easy. Of course, "Bass, I Love You" is a classic and a great test for sub setups, but let's just say it's not really a masterpiece biggrin.gif Dubstep and drum'n'bass typically have lots of great bass too, but most wub-wub bass patterns become old fast. Still, I've managed to find a few gems in the genre.

Try skrillex or Benny Benasi.
post #102 of 139
Thread Starter 
Quote:
Originally Posted by Toymachyne View Post

Try skrillex or Benny Benasi.

I've listened to a bit of those already (I like the Bangarang video a lot) and also Deadmau5 (e.g.Ghosts'n'Stuff is already in the Art of Flight soundtrack in the Reference 2 demo disc), but I think I like the dirtier sound of Datsik's robostep (e.g. Game Over, Retreat), and the fruits of the collaboration between Noisia and Foreign Beggars (e.g. Soul Purge -- what a bass drop!, Shellshock -- great video too!, No Holds Barred -- amazing bass textures that seem not to flow from the sub but instead are being thrown up in sticky, messy globs).

But really I like lots of different styles. The last Nine Inch Nails album (Hesitation Marks) have great quasi-subsonic passages. The funky bass lines in the last Daft Punk album (Random Access Memories) are great, and so is the dynamic range. I'm also slowly trying to understand jazz biggrin.gif
post #103 of 139
Andy I hope you are around because I have a serious question that I am dying to know the answer too. What is the difference on a actual electronic scientific level between the two filter options "peak" and "Sub EQ"? I have gotten drastically different results in decay times which is extremely obvious on my waterfall and spectrogram graphs.

Subs and speakers have not moved. The only thing is I raised the crossover all the way up to 150hz.

Here is graph using peak filters


Here is using a single sub EQ filter and one single small peak filter


Both have PGM 2 engaged which is a 3db bump from 45ish hz on down on submersives. The first has a 10db low shelf filter while the second has an 8db low shelf filter.

Here are a couple other waterfalls during the development of the house curve.

post #104 of 139
What is the difference between sub eq and peak filters?
post #105 of 139
I need my buddy to come over and help me setup this mini dsp correctly.

A quick question though, are you guys wiring in parallel or series? I wired my dayton HOs from my cv5000 in parallel so they are 4ohm load vs 2 ohm load because in my head I had the idea it is better for the amp and to keep the speakers within the 800watts max as recommended by the mfr. But I see others are juicing their speakers and loading their amps to max. Maybe I am shorting myself by 2dB.
post #106 of 139
Quote:
Originally Posted by jlpowell84 View Post

Andy I hope you are around because I have a serious question that I am dying to know the answer too. What is the difference on a actual electronic scientific level between the two filter options "peak" and "Sub EQ"? I have gotten drastically different results in decay times which is extremely obvious on my waterfall and spectrogram graphs.

Subs and speakers have not moved. The only thing is I raised the crossover all the way up to 150hz.

Here is graph using peak filters


Here is using a single sub EQ filter and one single small peak filter


Both have PGM 2 engaged which is a 3db bump from 45ish hz on down on submersives. The first has a 10db low shelf filter while the second has an 8db low shelf filter.

Here are a couple other waterfalls during the development of the house curve.


It's really hard to compare the first two waterfalls because one has a noise floor of 50 and the other 60, and one has a time limit of 450ms and the other 600ms. If you kept the same limits on both graphs it would be easier to see what's going on.
post #107 of 139
Ok I accept I have completely dropped the ball...
post #108 of 139
Quote:
Originally Posted by Toymachyne View Post

I need my buddy to come over and help me setup this mini dsp correctly.

A quick question though, are you guys wiring in parallel or series? I wired my dayton HOs from my cv5000 in parallel so they are 4ohm load vs 2 ohm load because in my head I had the idea it is better for the amp and to keep the speakers within the 800watts max as recommended by the mfr. But I see others are juicing their speakers and loading their amps to max. Maybe I am shorting myself by 2dB.

Hey there Toymachyne. I wrote you an answer back in the other thread with regard to the digital voltage controller for the amp fan. Hope I was able to help.

As I said there, I do not have a CV5000. However, I do run four of the Dayton 18HOs. Each pair is wired in parallel and each pair is then wired to a channel of my IPR amp.
You said you are wiring your subs in parallel.
The Dayton 18HO is a SVC 4ohm driver. If a pair of Dayton 18HOs is wired in parallel, it should be presenting as a 2ohm load to the amp.
If CV factory specs are followed, you are already sending about 1250 to each sub if that pair of Daytons is properly wired in parallel and hooked to one unbridged channel of the CV.

If you wired the pair of Dayton 18HOs in series, the pair would present an 8ohm load to one channel of the amp and each sub within a pair would be getting about 550 watts from an unbridged channel on the CV.

I assumed we were discussing the 18" Dayton HO subwoofers...in which case, I believe the recommended power handling per driver is 900 watts RMS and 1800 peak.

Hope that helps.
Edited by blah450 - 11/13/13 at 1:58pm
post #109 of 139
Quote:
Originally Posted by blah450 View Post

Hey there Toymachyne. I wrote you an answer back in the other thread with regard to the digital voltage controller for the amp fan. Hope I was able to help.

As I said there, I do not have a CV5000. However, I do run four of the Dayton 18HOs. Each pair is wired in parallel and each pair is then wired to a channel of my IPR amp.
You said you are wiring your subs in parallel.
The Dayton 18HO is a SVC 4ohm driver. If a pair of Dayton 18HOs is wired in parallel, it should be presenting as a 2ohm load to the amp.
If CV factory specs are followed, you are already sending about 1250 to each sub if that pair of Daytons is properly wired in parallel and hooked to one unbridged channel of the CV.

If you wired the pair of Dayton 18HOs in series, the pair would present an 8ohm load to one channel of the amp and each sub within a pair would be getting about 550 watts from an unbridged channel on the CV.

I assumed we were discussing the 18" Dayton HO subwoofers...in which case, I believe the recommended power handling per driver is 900 watts RMS and 1800 peak.

Hope that helps.

This helps a lot. I guess I could rewire to a 2ohm load and get some major power to these subs. But I would be only gaining like 4db gain.. They are plenty loud now... Thoughts?
post #110 of 139
Toy...I'm confused. It seemed as if you had said that your subs were already wired in parallel.
If that's the case, you are already sending them about the ideal amount of power from the CV.
post #111 of 139
Quote:
Originally Posted by blah450 View Post

Toy...I'm confused. It seemed as if you had said that your subs were already wired in parallel.
If that's the case, you are already sending them about the ideal amount of power from the CV.

Yep I wired them in parallel as I thought was correct. The subs seem to love the juice they are getting. I turned them up a bit today and they had to be turned back down again as I'm worried I will pop a seal on my windows smile.gif
post #112 of 139
Ha!

Unless I am missing something, you seem to have a great match between subs and amp, and wired for ideal power.

^^^^^This, as opposed to running each sub to its own channel (4ohm load) and getting about 1800 to each sub...might result in driver problems if levels are not monitored closely.

And of course, by running your sub pair in parallel to a channel, the other amp channel is still open for another set of subs!!!!!! biggrin.gif

Enjoy!
post #113 of 139

First off, thanks for the excellent guide neutro!

 

Quote:

Originally Posted by neutro View Post

....Note that in my experience, connecting and disconnecting the USB cable (thus powering on and off the MiniDSP if the back connectors are unused) does not lead to any loud pops and is thus safe to do with the subs turned on.
.....

 

There are lots of posts of people complaining about the MiniDSP's seemingly rather nasty power-on thumb/pop. Are you saying this can be avoided if one powers it through its USB port?

 

_____

Axel

post #114 of 139
No, they pop, not very loud, but they do thump when connected to the USB port on my Pioneer AVR. I am going to get it plugged into an always on socket instead.
post #115 of 139
Thread Starter 
Quote:
Originally Posted by Axel View Post

There are lots of posts of people complaining about the MiniDSP's seemingly rather nasty power-on thumb/pop. Are you saying this can be avoided if one powers it through its USB port?

Quote:
Originally Posted by RickD1225 View Post

No, they pop, not very loud, but they do thump when connected to the USB port on my Pioneer AVR. I am going to get it plugged into an always on socket instead.

Yeah disregard what I've said about that -- I think the auto on delay was responsible for the absence of thump/pop. That being said, I don't think it's very loud either.
post #116 of 139

LOL! Just realized you were the creator of this thread...I remember commenting on this on how good it was when it first came out. Makes perfect sense now. Great contributions Neutro.

post #117 of 139
Quote:
Originally Posted by neutro View Post

Quote:
Originally Posted by Axel View Post

There are lots of posts of people complaining about the MiniDSP's seemingly rather nasty power-on thumb/pop. Are you saying this can be avoided if one powers it through its USB port?

Quote:
Originally Posted by RickD1225 View Post

No, they pop, not very loud, but they do thump when connected to the USB port on my Pioneer AVR. I am going to get it plugged into an always on socket instead.

Yeah disregard what I've said about that -- I think the auto on delay was responsible for the absence of thump/pop. That being said, I don't think it's very loud either.

Thanks guys!

Keeping it on a permanent on outlet is not an option for me. I have some trigger-able outlets with and without delays to play with. I am hopeful I find a 'quiet' solution.

____
Axel
post #118 of 139
Question for neutro,

I would like to use the MiniDSP for EQing the sub. The intent is to just cut the peaks and not boost any nulls. My question is related to the logic of using the MiniDSP with room correction such as Audyssey. I do have REW and can measure the low frequency response. Assuming that the optimal placement of the sub has been found for smoothest in room bass response.

Connection as follows: AVR sub out ---> MiniDSP ---> sub LFE in

1. Disable all room correction features in the AVR.
2. Set the MiniDSP in bypass mode so that the AVR signal goes straight to the sub.
3. Measure the sub bass response using REW say from 15Hz to 300Hz
4. From the frequency response given in item 3, use the EQ feature in REW to determine the cuts at each frequency, the dB level and Q. The intent is get the smoothest response at the target frequency range. Save the filters file.
5. Enable PEQ output 1 and load the saved file from REW into the MiniDSP.
6. Remeasure using REW to see the frequency response has improved. Can compare item 2 to item 6. May have to do further adjustments in MiniDSP to dial it in.
7. Run the room correction feature in the AVR. Measure again using REW and compare with item 2, item 6 and item 7.

Does the above procedure make sense?
post #119 of 139
This was a great writeup by neutro

I'm really new to the sub EQ thing, so just a quick question: with Mini-DSP being available for so cheap, is there any point in looking into Anti-Mode for about 4x the cost? Thanks.
post #120 of 139
^
e-honda,

That really depends on how much one values simplicity and time. Anti-mode is very simple to use, almost plug and play. All the hardware is provided and results are satisfactory. My understanding is that the algorithm is quite good in that it's more than just a PEQ with IIR. I haven't had a chance to play around with Anti-mode and my understanding is based on reading some of the reviews + threads. Note that Audyssey XT32 with Sub EQ HT is a better bass solution for multiple subs. It's available on some of the higher end AVR models such as the Denon X4000 and Marantz SR7008. There is also the Onkyo TXNR929, but doesn't have Sub EQ HT

The material cost of comparing just the MiniDSP and Anti-mode is a bit misleading. Once you go down the MiniDSP route, you'll need a USB microphone (preferably calibrated one), hand held SPL meter (calibrated is better), boom stand, laptop/PC with HDMI/analogue inputs, HDMI or RCA cables, powered USB hub for long runs and USB cable.

Don't forget to factor in the time. MiniDSP requires a much deeper understanding of room modes and a willingness to roll up the sleeves to do more work. There is the software set-up, PC settings, modeling, etc. You'll have to get familiar with REW and carry out measurements. There is a bit of a learning curve and not for the faint of heart to spend countless days sorting out issues.

The great thing about the MiniDSP is the experienced/fun gained along the way. The ability to tweak things is a bonus.

So the question boils down to what you want?
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