Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[mojave]

I plan to be involved in a subwoofer shootout in October. I would like to use MC16 for playback of all material and EQ using the Parametric EQ. I will do a demonstration that shows off the Room Correction, Bass Management, and Parametric EQ. One nice feature is the channel mixing that would allow the subwoofer channel to be copied to other channels. Different subwoofers could be connected to each channel and compared easily by muting/unmuting channels during playback.

The hardware used will be a Firewire audio device with an ASRock ION 3D mini PC and BenQ W6000 projector. A calibrated measurement microphone will be used for all measurements.

The EQing of several of the subs will be done ahead of time. For peace of mind, it would be nice if the EQ settings could be saved as a separate file (similar to what other VST plugins allow). If they are saved via library backup, that would probably be sufficient. I haven't tested it yet.

Those of us involved plan to have a thread at AVS that goes through the setup, procedures, and opinions. I am trying to do some things that haven't been done before and are only possible using MC16.

Two features could help:

One challenge involves how to measure the subwoofers while sending the test signals through MC. I've mentioned this elsewhere, but I thought I'd say it again. If MC could accept a virtual line-in I think I would be set. I do like the MC16 ASIO driver option better, though. Making the Parametric EQ into a VST plugin would also work.

The other feature would be the ability to set start/stop positions for movies. This would make it easy to setup a playlist with clips from various Blu-rays and play them back. It would be nice to designate multiple clips from the same movie, too.

Any suggestions or other ways to showcase MC16 during the subwoofer shootout? Maybe I should get an ID and playback some music in a secondary zone.

[JimH]

Sounds like fun.  Your second request can be done with Playback Range as gappie describes.  It's a tag.

[mojave]

Your second request can be done with Playback Range as gappie describes.  It's a tag.

I and others haven't gotten it to work for video as you can read in this recent thread.

[JimH]

... Playback Range as gappie describes.  It's a tag.

It may only work for audio.  Sorry.

[mojave]

The subwoofer shootout has been set for October 22. A thread has been started at AVS regarding the shootout. I post there as desertdome.

 

[mojave]

This was posted at AVS today:

Get a demo disk for the movie sequence or you'll be pulling your hair out switching disks.

Use a program called mptrim to cut mp3s to your favored length without affecting bitrate or quality. This allows for a quick run through multiple songs as. well.

Can I tell him I'll just use JRiver Media Center 16 with its playlist and playback range capabilities? 

[JimH]

Why not?  Thanks.

[Matt]

For audio, playback range makes a long track (say a CUE) appear exactly the same as a smaller track.  The duration, seeks, etc. are all updated.

For video, this would be a bit of work.

Will you promise to be a blowhard about how great Media Center is for subwoofers if we get it working

(p.s. why would you use MP3 in a critical listening / testing environment?)

[JimH]

mojave,
Aren't you expert in this area also?
http://www.avsforum.com/avs-vb/showthread.php?t=1350208

[mojave]

For audio, playback range makes a long track (say a CUE) appear exactly the same as a smaller track.  The duration, seeks, etc. are all updated.

For video, this would be a bit of work.

Will you promise to be a blowhard about how great Media Center is for subwoofers if we get it working

I will if I can attend! My wife is due November 12 (I was shooting for a delivery of 11/11/11  ), but due to a high risk pregnancy the doctor may want to induce as early as 36 weeks, but no later than 38 weeks. This puts the delivery as early as October 15 (same day as my oldest son) or as late as October 29. The GTG is scheduled for October 22.

I am helping plan the GTG and am supposed to be doing all the measurements. My plan was to showcase all the new MC16 stuff including parametric EQ.

(p.s. why would you use MP3 in a critical listening / testing environment?)

Probably because someone downloaded them from torrents. I don't have any compressed audio in my library.

[mojave]

mojave,
Aren't you expert in this area also?
http://www.avsforum.com/avs-vb/showthread.php?t=1350208

I played with it a long time ago, but never felt it was worth implementing. I'll try to help.

[JimH]

Thanks.

[mojave]

For audio, playback range makes a long track (say a CUE) appear exactly the same as a smaller track.  The duration, seeks, etc. are all updated.

For video, this would be a bit of work.

I was thinking about this some more. You already can specify a start for a video using auto-resume. Would it be that hard to just add a stop timestamp? This seems like it would be fairly easy to do. It would be nice to be able to right click the movie and set start/stop places. This method would only allow for one playback range in a movie unless the database field allowed for multiple entries.

Another idea is to create a feature called "Trailer Creator" or "Demo Designer" or something like that. This would allow users to create their own custom trailers or demos for movies. The trailer/demo files could be shared in Interact with other users (as long as the other users had the same movies). Other users could also delete scenes for movies they didn't own. Multiple start/stop locations could be specified for multiple movies. The user could reorganize the virtual clips and even do a transition page with text between clips. I can see the a lot of users getting interested in the demo ability of this feature.

[Matt]

In a coming build:
NEW: Playback range is supported for video playback.

[mojave]

Great!  Now if I can figure out how to measure the PEQ changes with REW in a manner acceptable to "everyone" at AVS.

Here are the subwoofers that will be present:

Chase Home Theater CS 18.T (2), SS 18.2, VS 18.1
Rythmik 15” Sealed Sub (DIY with DS 1500 driver & A370 amp)
Elemental Designs (eD) sub (If Alex, the owner of eD attends. ED is 2 1/2 hrs east of Omaha.)
JTR Powered Captivator
Motor City Custom Audio MFW-Turbo (2) - These have custom 15" drivers from Acoustic Elegance and Dayton SA1000 amps.
MFW-15 Dual Opposed Sealed DIY (4) - These will use a total of eight 15" drivers made by Eminence and 2 Dayton SA1000 amps. 
Cinema F-20 (2) - These are horn subwoofers with one 15" driver each. Both will be powered by a single Samson SX1200 amp.
Klipsch Sonotube DIY
Danley DTS-10 (EP4000)
JTR Growler (EP4000)
HSU VTF-3 HO

I am buying materials this weekend for the Cinema F-20 subs and the Dual Opposed Sealed subs. We plan to spend a few evening between now and October 22 setting up many of the subs in HuskerOmaha's basement and EQ'ing them. Our goal is a fairly flat frequency response at the listening position regardless of which sub is playing. If I can use JRiver, I may setup a zone for each subwoofer or subwoofer combo. We can position the subwoofer(s), connect it, and then select that zone in JRiver and start playback of the music/movie demo tracks. Having all the presets done in JRiver will help speed things along greatly.

The owner of Chase Home Theater (Craig), JTR (Jeff), Elemental Designs (Alex) have all been invited. I don't know how profitable it is to come from a business perspective, but anyone from JRiver is welcome to attend. There will be food!

[mojave]

The two Cinema F20 front loaded horn cabinets and the four dual opposed sealed subwoofer cabinets have now been made. A coworker of mine built them this past weekend. I still need to fill nail holes, prime, paint, and load the drivers. The two Cinema F20 subs will be connected to one Samson SX1200 amplifier. Both Cinema F20 subs with 2 drivers and 1 amp cost $790.

Two of the dual opposed subs will be connected to one Dayton SA1000 amp (225 watts per driver). The cost for all four dual opposed subs with 8 drivers and two amps is $1861. These will produce incredible output all the way down to 5 Hz.

[lbstyling]

Hi,
Ive spent many years building speakers and subs for h/t and car audio-

 have a look at a jbl 2242h.... I know I know, large box, low qt, not exactly what most people are designing around these days, but bear with me-

for many very complicated technical reasons, this is a formidable driver,
the efficiency is very high (99db/1w) it rolls off below 30hz, but in room this isnt anything like as bad as you would expect, dynamic range isnt compressed due to efficiency like almost everything else (power compression), the low qt gives you a kick that you cannot get with a modern design, and its almost indestructible.
Because of all this, it also handles eq very well. You trade off extreme extension for the ability to follow the waveform accurately, the truth reveals itself when you play music though (pref classical)
Its good enough for pinewood studios down the road from me, and its good enough for IMAX theatres too. Ive had one for 3 years now, Ive had a rhythmik 15, a svs pc13 ultra and various even more mad diy options and im never changing.

although they cost a lot new, you'll get one easy on fleabay for $150.

[mojave]

I have been working on the measurement side of things in anticipation of finishing the subs soon. I came across this thread at HomeTheaterShack that has a nice youtube video showing how to create filters in REW and use them in a Digital Audio Workstation (DAW). This translates very nicely to using the filters in JRiver and shows how to get before and after measurements using REW.

One thing that would greatly speed up the process is if JRiver could import the filters from REW. REW allows one to export the filters as a text file.

The youtube video shows how moving around the room can change the room correction that is needed. If we EQ before the GTG, then adding all the people and more subs might change things. If we could do a sweep with REW, load the filters into JRiver, and then play the REW generated pink noise file through JRiver, we could quickly see if the sub is flat in the room even with all the people, etc. This could be refined to only take a few minutes for each subwoofer and would greatly enhance the accuracy of the listening experience.

[Matt]

One thing that would greatly speed up the process is if JRiver could import the filters from REW. REW allows one to export the filters as a text file.

Could you email me a few sample files?

Thanks.

[mojave]

I sent an e-mail with several sample files.

[mojave]

The subs have been sanded, primed, and painted. The second coat of paint is being applied tonight. I'll start loading the drivers in the next couple days. Monday I purchased a boom microphone stand off Craigslist for $15 to hold the measurement mic. Today I found a server rack for $50 to hold all the amps and gear.

I am definitely using JRiver for playback and all the EQing of the subs! I started building a playlist and the Playback Range tag works great! I've requested in the REW sub at HomeTheaterShack that JRiver be included as an equaliser for exporting filters (I have to use the "s" at the end of equaliser since John, the developer of REW, is from England).

Here is the measurement and EQ methodology in a nutshell:

1.  Measure the frequency response from the listening position using REW.
2.  Open the EQ window and select your target settings and filter tasks. For filter tasks I specified a maximum boost of 12 dB per filter with an overall maximum boost of 9 db. I set it for a 1 dB flatness target.
3.  Click "Match response to target" in the EQ window. REW will then generate the filters.
4.  Click the "EQ Filters" button in the EQ window to show the filters. I then sorted them by frequency.
5.  Open JRiver's Parametric Equalizer DSP and enter the filters.
6.  Use REW's Generator to make a Pink PN wave file. I selected an FFT length of 131072.
7.  Open REW's RTA window and then open the settings. Set the mode to RTA 1/48th octave, the FFT length to 131072, the averages to none, and the Window to Rectangular. I also checked "adjust RTA levels."
8.  Playback the Pink PN wave file in JRiver while watching the REW's RTA. Without any EQ the frequency response is identical to the original measurement by REW. This means JRiver isn't changing anything. When the Parametric Equalizer is checked, the frequency response in the RTA flattens out and matches REW's predicted frequency response.
9.  Adjustments can be made on the fly to JRiver's Parametric EQ while the Pink PN file is being played back. You can watch the effect of the changes in the RTA.

A quick way to check for the sub's best location in the room is to place the sub in the listening position (if possible). Playback the Pink PN file in JRiver with no EQ while using the RTA feature of REW. Move the microphone around the room or to all possible sub locations. You can save a graph of each location and evaluate further later. Place the sub in the location with the flattest frequency response. You can wear earplugs if you tire of hearing the pink noise.

Here is an example of entering the filters:

[mojave]

Greg (HuskerOmaha at AVS) and I finished the subwoofers last night. We then had to carry all six subs down into his basement theater. I think we finished at about 11 pm.

I had brought a Flash Drive with a portable J River installation. It worked fine, but after I closed it and tried to open it again it said my license had expired. Can I copy the license from my HTPC/Work computer or do I need to download the license? I tried to open the portable installation on my work computer, but it just keeps opening my standard installation.

Each subwoofer or subwoofer grouping will be its own zone. That way we can setup all the EQ/Room Correction and easily switch between subwoofer(s).

Any update on importing a REW filter file?

[Alex B]

Are you familiar with the subwoofer tests that Ilkka Rissanen (aka Ilkka R, aka Zipman) performed 2005-2007? The tests are now quite legendary.

http://www.dvdplaza.fi/forums/forumdisplay.php?f=157

The test results are mostly presented in English, but comments are mostly in Finnish. Google Chrome should be able to translate the Finnish parts automatically, but I can help if the translation looks like gibberish.

Back then the tests were discussed also at avsforum.com and avforums.com (UK).

The interesting thing in those test is that the room was eliminated from the list of affecting factors by performing the tests outside. The subs were only measured (using scientifically valid methods) - i.e. no listening tests were performed.

When subwoofers are compared in a listening test, the test can be valid only for the particular subwoofer & room combinations (unless the test is actually performed outside or in an anechoic chamber ). In addition, if you are testing in a room you would need to place each tested subwoofer exactly in the same spot (one at a time) to get more valid results.

[JimH]

I had brought a Flash Drive with a portable J River installation. It worked fine, but after I closed it and tried to open it again it said my license had expired. Can I copy the license from my HTPC/Work computer or do I need to download the license?

No.  Installing it from a PC on which you have a license should be enough.

Double check the system date on the PC.

[mojave]

Are you familiar with the subwoofer tests that Ilkka Rissanen (aka Ilkka R, aka Zipman) performed 2005-2007? The tests are now quite legendary.

I've read those many times. I'm glad Josh Ricci is continuing the measurements. He plans to have data-bass.com updated soon with all his latest tests. His tests and articles will also now be published at Audioholics, such as his recent test of the SVS PB13-Ultra.

Since Josh is doing such a great job of objective testing, we are trying to give the attendees and ourselves a chance to answer these questions:

• What do different alignments sound like if the same driver is used for consistency?
• Do people prefer more midbass output or low bass output?
• Does EQ make a difference in listening?
• Can attendees tell if EQ is on/off?
• At what volume do capabilities start to make a difference (bass extension, output)?
• Does location make a difference in listening?
• What does unlimited bass sound like? (8 dual opposed sealed with 15" drivers and 2 sealed with 18" drivers)?
• Can sealed and ported subwoofers be combined for satisfactory results?
• Do attendees prefer the effect of nearfield subs +/- usual placement (wall locations) and with what type of bass output?
• How much does the Q of the sub have to change before it is noticable?

Because of the ease of using JRiver, we will be able to do things at this GTG that haven't been done before. For example, we can have three identical subs in three different locations in the room. We can listen to a 1 1/2 minute clip of Iron man through each sub with EQ off and with EQ on. This will help demonstrate how much the room actually dominates the frequency response.

[mojave]

No.  Installing it from a PC on which you have a license should be enough.

Double check the system date on the PC.

I forgot to mention that the portable installation had taken an update on the foreign PC. After installing the update and restarting is when I actually got the message.

I'm not sure about the date. I'm going to try it on another computer in my office today (if there is an update) and see if I have the same problem.

[mojave]

Could you email me a few sample files?

Thanks.

Any progress with the sample files? I will only be generating PK filters so those are the only type that needs to be supported for starters.

We will have 13 subwoofer setups and I will create a zone for each setup ahead of time. I'll then add 8-10 dummy filters per setup. Once I get the filters generated in REW, I plan to manually enter them all in. It would save some time, though, if I could just import the filters.

REW's Real Time Analyzer makes it easy to see the effects of changes to sub location, distance settings, crossovers, slopes. Currently these settings are changed with a mouse click or mouse click/drag and are done on a per speaker basis. It would be great to be have a dial that can be controlled with the mouse in order to quickly change crossover frequency, slopes, or distance settings. I really like the dials used in Voxengo plugins. It would also be helpful to be able to link channels so that the crossover, for example, can be changed for the mains without having to go to the separate tabs.

[mojave]

Last night I setup a new zone so that I could use different EQ settings with REW and to make sure things were going to run efficiently for the GTG. I wish I could copy a zone, but I haven't found a way to do that yet. It takes a while to setup the audio/video settings and the DSP. After entering all settings I then played back some pink noise to start calibration. Maximum volume came out of the speakers and subs and I was so assaulted by the sound I could hardly think how to shut it off!I have 1000 watts for each of my two subs and 380 watts/channel for my mains so it was loud! I realized I had forgotten to change the zone from system volume to internal volume. I am using ASIO output so the system volume is bypassed.

[JimH]

Are you OK?

[mojave]

My ears hurt for a few minutes, but that is it. Fortunately I didn't damage my speakers.

One feature request I have is that "Mix Channels" should be a separate DSP or we should be able to add Parametric EQ more than once. For some setups it is helpful to copy a channel before Room Correction and Parametric EQ. Also, when testing the effects of EQ it is easier to turn the whole DSP on or off rather than clicking 15 filters. However, if I turn the whole DSP off I lose the channel mixing. I use "Mix Channels" to copy the subwoofer output to outputs 7 & 8 for other subs or for subwoofer/midbass combos. By having the subs on separate channels I can set independent distance and gain settings.

[JimH]

So I take it you didn't win.

[mojave]

So I take it you didn't win.

JRiver was the winner! 

I've been busy with my write-up at AVS and catching up on life after my son was born that I haven't posted here yet. The Subwoofer GTG was great. We had three internet direct speaker manufactures present:  Mark Seaton of Seaton Sound, Jeff Permanian of JTR Speakers, and Craig Chase of Chase Home Theater. On Friday evening we had those three show up plus three out of town attendees. The host for the GTG, Greg (HuskerOmaha at AVS), let the out of town attendees sleep in his theater during the night. That night we took a bunch of room measurements, seat to seat measurements, and finalized our playlist. I didn't leave until 2 am.

I arrived at 9:30am on Saturday and we actually didn't start listening to subs until about 11. I would setup the subs and make all connections, measure the frequency response from the mic location (between the two main seats), generate EQ filters in REW, enter the filters in JRiver, and then remeasure. Then I would start the playlist and we would listen to Blu-ray clips for about 20 minutes and then music clips for about 5 minutes. Although we had about 15 people total during the day, only 6 of them participated in ranking the subwoofers.

We used JRiver V17 for playback and I had made a playlist for the day. For the Blu-ray or music clips, I entered a range into the Playback Range tag. I also set the Use Bookmarking tag to No. For some reason the playlist kept wanting to skip certain Blu-ray clips. I had to manually double click them in the playlist to play them.

We sent the output directly to the amps so no receiver was used. I used the Room Correction DSP for all distance and level settings. All the subwoofers were EQ'd flat at the mic position using filters provided by REW. It usually took only 4-6 minutes from the initial measurement until we did the measurement with EQ. I did get tired of typing all the filters into JRiver Parametric Equalizer, but for one or two subs it is no big deal. Many were very interested in the EQ capabilities of JRiver. For dual subs I used the Mix Channels to copy the subwoofer to the RL channel. For the Danley DTS-10 and JTR Speakers Growler combo I was able to put a low pass on the DTS-10, and high pass on the Growler, and level adjust them all using the Paramentric EQ. One of the subs was sealed and used an external amp. On this sub I added a Linkwitz Transform filter to boost the low end before adding the EQ.

This GTG could not have gone as smooth without using JRiver. Thanks for all the great features!

There are a lot more details and writeup at AVS. The thread is called Subfest 2011 - HuskerOmaha and Desertdomes Subwoofer Showdown. I post as desertdome at AVS and you can read my comments starting with post 10.

[JimH]

JRiver was the winner! 

Thanks to your tenacity and Matt's toil.

There are a lot more details and writeup at AVS. The thread is called Subfest 2011 - HuskerOmaha and Desertdomes Subwoofer Showdown. I post as desertdome at AVS and you can read my comments starting with post 10.

It's truly one of the most in depth threads I've seen at AVSForum.  Thanks for the great report.  And congratulations again on your new son!

[mojave]

Pictures of the Subwoofer GTG are now available on Flickr.

Here are my subwoofers. I'm not in the picture.


I am entering the REW filters in JRiver's Parametric Equalizer.


I bought a rack off Craigslist for the GTG. It has 6 of my amps and my Steinberg MR816x audio device mounted in it.


There are about 4-5 guys that weren't around when we took the group picture.

[mojave]

I took part in another subwoofer GTG this past weekend. This was a blind subwoofer comparison with 7 pairs of subwoofers plus a pair of Klipsch RW-12d subs we listened to at the beginning. I was a listener and didn't have anything to do with the setup/organization of this GTG. I felt it could have gone smoother with JRiver. We had a great time and a lot of us were up from 9 am Saturday to 5:30 am Sunday.

Here is the link to the write-up at AVS: http://www.avsforum.com/avs-vb/showthread.php?t=1387178.