Guide to Subwoofer Calibration and Bass Preferences - Page 38 - AVS Forum | Home Theater Discussions And Reviews
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post #1111 of 1404 Old 02-24-2019, 05:53 AM - Thread Starter
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Originally Posted by morgiastic View Post
Hi Mike,
Thank you for your reply. What you are saying sounds vaguely familiar, perhaps something I had read about back in the day, but didn't understand well enough for it to stick with me. Anyway, mostly a theoretical question, now for something more substantial.

It's probably not controversial to say that a PC-13 Ultra doesn't do it's best work in the 200 Hz range, but not in my system, in any case. Also, tends to pull the image to the left, where the sub is located, so I'm crossing-over at 80 and living with the consequences, at the moment. But, it would be nice to know if anything can be done about it. Rearranging the room in any significant way isn't a practical option at the moment (all needs to be renovated, ultimately, but even just moving the furniture around to any significant amount isn't happening right now). Is there any way to force Audyssey to attend to those frequencies? They are there, I can hear them, even if the mic can't. Does the app allow for this, by chance?

Thank you,
Morgan.
Hi Morgan,

You are very welcome! The app wouldn't be able to help with the problem that you are describing. It allows users to make some adjustments, after the fact, to the frequency response; and it allows users to limit the frequency response to be EQed. But, the Audyssey program, working in conjunction with your AVR, sets crossovers based on what the Audyssey microphone "hears".

Based on your description, it sounds to me as if your Audyssey microphone is not functioning correctly. I would buy a replacement microphone and try that. Replacement microphones can be found on Amazon. The color doesn't matter, as the mics are generic. Just make sure that you are matching the same general type of microphone, such as the tower type that points up. I believe that there is an example listed in the Audyssey FAQ, linked in my signature.

Regards,
Mike

GUIDE TO SUBWOOFER CALIBRATION AND BASS PREFERENCES

* The Guide linked above is a comprehensive guide to Audio & HT systems, including:
Speaker placements & Room treatments; HT calibration & Room EQ; Room gain; Bass
Preferences; Subwoofer Buyer's Guide: Sealed/ported; ID subs; Subwoofer placement.
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post #1112 of 1404 Old 02-25-2019, 08:45 AM
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I am familiar with sub calibration. Theater has 4 x 18" ported subs run in two pairs with a BFD FBQ1000 for PEQ. The BFD is cool because I can EQ each pair, then run REW and EQ the combined output (4 subs) and EQ those also by "linking" some PEQ channels. This has proved effective in the theater even without delay for each sub in the BFD. Of course, Audyseey is run after the subs are sufficiently calibrated.

I have 2 sealed 12" subs in my 5.1 living room setup. They each have their own bass management within the Denon 4311 AVR. I was using an old AudioControl Richter scale to EQ them, but as the EQ is only one channel, they would be EQ'd as a pair. This was not ideal so I very recently got a Dayton Audio DSP-408. It is similiar to the miniDSP out there.

With 4 inputs and 8 outputs, I have more than enough availability for the 2 subs in the living room. It does have limitations however.

I spent quite a bit of time over the weekend messing with calibrating these two subs. I can get each one pretty flat individually. But when I combine them, the resulting output via REW fed by a UMIK-1 is all over the place. I mess with polarity of each sub individually and combined, change the delay of each sub (the DSP-408 has a max of 8ms delay per channel) finally getting the flattest output with both subs at 0 deg polarity and the nearest sub a 2ms delay.

The resulting graph is not acceptable to me though. Again, each sub is flat when EQ'd individually, but when combined, the graph is all over the place. What is going on? I didn't have this issue in the theater room. Perhaps because there are 4 subs, so room modes are better controlled. The 2 subs are doubling as stands for the front left/right speakers (this setup is also used extensively for 2 channel listening, mostly vinyl), so moving them is a last, last resort.

I know you will want a graph, but I am at work and don't have one handy. I do not think the DSP-408 will allow me to combine the outputs like the BFD does. (It does have a channel "linking" option, but it does not allow the linking of PEQ channels like the BFD, only the output channels).

Should I abandon the individual EQing and just EQ them combined (which would be done by "linking" channels one and two that I am using)? Any suggestions would be appreciated.
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post #1113 of 1404 Old 02-25-2019, 09:38 AM
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ESW-V10 - no gain control

This is amazing. Great information.

I've been trying to get better bass in my system. I have a Denon 2310ci AVR, and engery RC speakers (RC-10's for FL/FR, RC-LCR center, Veritas mini for surround, and ESW-V10 for the sub). I ran Audessey (with the volume control on the sub at 50%) and Audessey set my SW channel level at -9.0. Crossovers are at 80 for center, 90 for FL/FR, and 100 for surrounds. I get very little bass and certainly no vibrating bass in movie soundtracks (tested a good one last night after reading a lot of your sticky: where Ky-Lo Ren is introduced and he makes a shot stick in mid air and Po is walked past that blaster).

I increased the SW channel level in the AVR from -9.0 to +4.0. I like the sound much, much better. After reading your guide, I note the suggestion to keep the AVR channel level to -5.0 and adjust the gain on the sub. I don't have a gain control on my sub, just a volume level. So, I was thinking of putting the AVR channel level at -5.0 and then increasing the volume on the sub, but that doesn't keep my sub volume relative to the other sounds (which is what the gain control does, from my reading of the sticky here).

So - if you don't have gain control on the sub, are there other suggestions or do I just do as proposed above?

P.S. - I have DEQ on, trying Audessy-Flat curve right now, and Dynamic Volume off.
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post #1114 of 1404 Old 02-25-2019, 09:39 AM - Thread Starter
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Originally Posted by legierk View Post
I am familiar with sub calibration. Theater has 4 x 18" ported subs run in two pairs with a BFD FBQ1000 for PEQ. The BFD is cool because I can EQ each pair, then run REW and EQ the combined output (4 subs) and EQ those also by "linking" some PEQ channels. This has proved effective in the theater even without delay for each sub in the BFD. Of course, Audyseey is run after the subs are sufficiently calibrated.

I have 2 sealed 12" subs in my 5.1 living room setup. They each have their own bass management within the Denon 4311 AVR. I was using an old AudioControl Richter scale to EQ them, but as the EQ is only one channel, they would be EQ'd as a pair. This was not ideal so I very recently got a Dayton Audio DSP-408. It is similiar to the miniDSP out there.

With 4 inputs and 8 outputs, I have more than enough availability for the 2 subs in the living room. It does have limitations however.

I spent quite a bit of time over the weekend messing with calibrating these two subs. I can get each one pretty flat individually. But when I combine them, the resulting output via REW fed by a UMIK-1 is all over the place. I mess with polarity of each sub individually and combined, change the delay of each sub (the DSP-408 has a max of 8ms delay per channel) finally getting the flattest output with both subs at 0 deg polarity and the nearest sub a 2ms delay.

The resulting graph is not acceptable to me though. Again, each sub is flat when EQ'd individually, but when combined, the graph is all over the place. What is going on? I didn't have this issue in the theater room. Perhaps because there are 4 subs, so room modes are better controlled. The 2 subs are doubling as stands for the front left/right speakers (this setup is also used extensively for 2 channel listening, mostly vinyl), so moving them is a last, last resort.

I know you will want a graph, but I am at work and don't have one handy. I do not think the DSP-408 will allow me to combine the outputs like the BFD does. (It does have a channel "linking" option, but it does not allow the linking of PEQ channels like the BFD, only the output channels).

Should I abandon the individual EQing and just EQ them combined (which would be done by "linking" channels one and two that I am using)? Any suggestions would be appreciated.

Hi,

Seeing a graph may help a little in understanding how bad the situation is. But, if the frequency response is all over the place, I don't really think that seeing the graph will help in diagnosing the problem, or in suggesting a solution. This doesn't sound as simple as cancellation at the crossover to the mains, or something like that.

Is the visible graphed problem matched by an audible problem? Sometimes, REW is not our friend if we can't actually hear the problems it shows us. In any event, I suspect that you are just going to have to keep experimenting. If you haven't already tried Audyssey by itself, I would probably do that. Afterwards, I might try to use the Dayton to fine-tune the Audyssey result. (In theory, I believe that 8ms of delay should be enough, at least below about 80Hz.)

I understand that you don't want to move the subs, but if you can get one of the subs to work well by itself, then you may want to consider stacking them, or placing them side-by-side. Other than to add 6db more SPL (averaged over the subs' passband) the biggest reason to have multiple subs is to improve the frequency response. But, if dual subs degrade the FR instead, then it may be time to rethink the subwoofer placements. Getting speaker stands, and moving the subs either very close together, or much more widely separated (perhaps on different walls) may have to be an option, if all else fails.

Regards,
Mike
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GUIDE TO SUBWOOFER CALIBRATION AND BASS PREFERENCES

* The Guide linked above is a comprehensive guide to Audio & HT systems, including:
Speaker placements & Room treatments; HT calibration & Room EQ; Room gain; Bass
Preferences; Subwoofer Buyer's Guide: Sealed/ported; ID subs; Subwoofer placement.
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post #1115 of 1404 Old 02-25-2019, 09:57 AM
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Originally Posted by mthomas47 View Post
Hi,

I don't have any experience with Trinnov, but based on what you are saying, I don't know that you are doing anything wrong at all. A -5 gain level is fairly high, where the digital gain on the PB16 only goes up to 0. My guess is that the single subwoofer is simply having to strain a little too much for movies, and that you hear some distortion as a result.

Low-frequencies put more strain on a subwoofer than mid-bass frequencies do, and some movies go much lower in frequency, and require much more low-frequency SPL, than most two-channel music does. Among other things, the .1 LFE (low-frequency effects) channel is played 10db louder than the bass content in the regular channel. So, 5.1 movies can put additional strain on our subwoofers in several different ways.

Depending on your room size (which will affect how much room gain you are getting to augment your low-bass) and depending on your master volume level, which also requires your subwoofer to play louder, you may just be asking a single 15.5" subwoofer to do a little more than it is capable of doing. The PB16 is an excellent sub, but all subs have limits. Short-term, I would probably back down the movie trim level by a couple of decibels or so, and see if that helps. Long-term, you may just need more firepower for your room, and your preferred listening levels.

Regards,
Mike
I had actually purchased Three SVS PB-16s and I already Own a Velodyne DD18. I earlier had set the Sub Trim Level in Trinnov to +6db for all the four subwoofers. The 3 PB-16 broke. Today it was repaired and I Did the Calibration again in the Trinnov with the four subwoofers connected. While Calibration I set the gain level of the Subwoofers at -18db,-15db,-12db and 30 for Velodyne.

This time around I am getting good results for Movies. The bass is solid but there are certain dips and peaks still left to be addressed.

Trinnov provide a PEQ filter which can be added to each channel and the subwoofer channel too. Can I remove the Peaks and Dips with the PEQ Filter, What measurement equipments do I need if Yes.

Thank You,
Rohit
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post #1116 of 1404 Old 02-25-2019, 11:07 AM
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Hi,



I understand that you don't want to move the subs, but if you can get one of the subs to work well by itself, then you may want to consider stacking them, or placing them side-by-side. Other than to add 6db more SPL (averaged over the subs' passband) the biggest reason to have multiple subs is to improve the frequency response. But, if dual subs degrade the FR instead, then it may be time to rethink the subwoofer placements. Getting speaker stands, and moving the subs either very close together, or much more widely separated (perhaps on different walls) may have to be an option, if all else fails.

Regards,
Mike

Thanks Mike for the thorough reply. I have contemplated all you've suggested: Moving both subs to a corner and put speakers on stands, running REW after Audyssey. I even thought of just running one sub and leaving the other as furniture. LOL. I will follow up with my eventual solution. Hey, we do this because it is fun right?
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post #1117 of 1404 Old 02-25-2019, 04:15 PM - Thread Starter
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Originally Posted by galaxyluv View Post
I had actually purchased Three SVS PB-16s and I already Own a Velodyne DD18. I earlier had set the Sub Trim Level in Trinnov to +6db for all the four subwoofers. The 3 PB-16 broke. Today it was repaired and I Did the Calibration again in the Trinnov with the four subwoofers connected. While Calibration I set the gain level of the Subwoofers at -18db,-15db,-12db and 30 for Velodyne.

This time around I am getting good results for Movies. The bass is solid but there are certain dips and peaks still left to be addressed.

Trinnov provide a PEQ filter which can be added to each channel and the subwoofer channel too. Can I remove the Peaks and Dips with the PEQ Filter, What measurement equipments do I need if Yes.

Thank You,
Rohit

Hi,

I'm not sure that I can help you at all with this, but I'll try to help a little. First, I think that you probably need to buy a calibrated Umik-1 and download REW (which is free) and start measuring your frequency response. I am surprised that you can make three PB16's and your Velodyne subwoofer sound very good together. At a minimum, I might expect some cancellation around the port tune of the Velodyne sub, even if you run all three PB16's in Standard (20Hz) mode rather than in Extended (16Hz) mode.

Measuring your frequency response will let you see what you are dealing with, before you start playing with PEQ. You may also need to buy a miniDSP HT to properly deal with whatever your REW measurements show you. The global subwoofer channel EQ that Trinnov performs may not be sufficient if you are, in fact, experiencing integration problems with the four subs. Once you have REW, you can see exactly what is going on.

But, I would personally be inclined to start-off with just the three PB16's (well-distributed on opposing walls) and see what kind of frequency response you can get that way. Ideally, in order to take full advantage of the PB16's, you would like to run them in the Extended 16Hz mode. And, you are pretty well guaranteed to get cancellation with your Velodyne if you run the PB16's in that mode with the Velodyne also in the signal chain. It may be that the SVS subs will work better by themselves, and if you do try to integrate the Velodyne with them, it may take a lot of effort to get a good result.

Once you get started with REW, I would post on the thread I am linking for you below. I believe that some of the people who regularly post on that thread may be able to help you more than I can, when it comes to learning how to use REW, and with integrating non-matching subs. I hope that I have been able to help at least a little.

https://www.avsforum.com/forum/91-au...et-graphs.html

Regards,
Mike
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GUIDE TO SUBWOOFER CALIBRATION AND BASS PREFERENCES

* The Guide linked above is a comprehensive guide to Audio & HT systems, including:
Speaker placements & Room treatments; HT calibration & Room EQ; Room gain; Bass
Preferences; Subwoofer Buyer's Guide: Sealed/ported; ID subs; Subwoofer placement.
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post #1118 of 1404 Old 02-25-2019, 04:50 PM
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Hi,

I'm not sure that I can help you at all with this, but I'll try to help a little. First, I think that you probably need to buy a calibrated Umik-1 and download REW (which is free) and start measuring your frequency response. I am surprised that you can make three PB16's and your Velodyne subwoofer sound very good together. At a minimum, I might expect some cancellation around the port tune of the Velodyne sub, even if you run all three PB16's in Standard (20Hz) mode rather than in Extended (16Hz) mode.

Measuring your frequency response will let you see what you are dealing with, before you start playing with PEQ. You may also need to buy a miniDSP HT to properly deal with whatever your REW measurements show you. The global subwoofer channel EQ that Trinnov performs may not be sufficient if you are, in fact, experiencing integration problems with the four subs. Once you have REW, you can see exactly what is going on.

But, I would personally be inclined to start-off with just the three PB16's (well-distributed on opposing walls) and see what kind of frequency response you can get that way. Ideally, in order to take full advantage of the PB16's, you would like to run them in the Extended 16Hz mode. And, you are pretty well guaranteed to get cancellation with your Velodyne if you run the PB16's in that mode with the Velodyne also in the signal chain. It may be that the SVS subs will work better by themselves, and if you do try to integrate the Velodyne with them, it may take a lot of effort to get a good result.

Once you get started with REW, I would post on the thread I am linking for you below. I believe that some of the people who regularly post on that thread may be able to help you more than I can, when it comes to learning how to use REW, and with integrating non-matching subs. I hope that I have been able to help at least a little.

https://www.avsforum.com/forum/91-au...et-graphs.html

Regards,
Mike
I have an option of FIR Filters in the Trinnov. What are these filters for as compared to PEQ. Does REW address the FIR Filters. How about using the Acourate software for this purpose
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post #1119 of 1404 Old 02-25-2019, 06:45 PM
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Setting phase with REW before running ARC

After level matching, I had previously adjusted the phase on my 4 SB16's in the traditional manner. Furthest sub with each sequentially to maximize DBs. I had been able to add 10.7 dbs. I had also experimented with adding 1+2, then 1+2+3, then 1+2+3+4 to maximize dbs, getting a slightly lower total addition.
However, after an extended conversation with Ed Mullen, I followed his suggestion to use REW adding each sub in turn: i.e. 1+2, 1+2+3, 1+2+3+4
adjusting for the flattest response. Ed had stated that you might not want the maximum Dbs. However, as it turned out, I got an additional .2 with this method. Curiously, to me, the best response was with all 4 subs' phases set to 0.
Ran ARC, EQ'd to 500hz ARC set sub trim to -8.
Changed LFE to 120 and removed low pass filters in subs (according to Ed Mullen)
Then, using REW, tested distances between 11-22 ft for subs. 22 ft. was best. In the past, 11 ft had given flattest Then raised each sub by 6.
The difference in the quality of the sound is astonishing. I can't explain what happened, but am now truly set for the foreseeable future as far as sub performance is concerned.
Again, thank you to everyone who has contributed to these forums over the past several months. As most of us experience, the improvements have been incremental; an idea here, a thought there. I'm so far from where I started, I really am not sure of each individual step, but the combined input has gotten me to a completely different destination than when I started.
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post #1120 of 1404 Old 02-26-2019, 09:02 AM
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Took me two days, but I made it to the end of the article! Excellent work, incredibly comprehensive. Sure there is a lot of repeat information, but I understand why. Should be required reading for anyone interested in learning about subwoofers, all in one place. Been enjoying my Rythmik F12G for 10 years now, perfect for a small apartment, with the purchase of a new Denon 3500 AVR, I wanted to make sure I relearned all that I forgot, so I could choose the the right settings before running the latest Audyssey XT32. Your immense research and article was great in confirming what I’m doing here. Though I will say I’m still a bit confused about The Audyssey trim level debate between your more updated information versus the now older Audyssey setup thread which I reread as well. With my gain control knob at about 1:00 clock on the dial, I get the same results I did 10 years ago, “-3.5 dB”. Living in a small apartment does not allow me to even consider boosting my subwoofer manually, though I wish at times I could. Music formats are so all over the place, my sub can sound too intense or too tame depending on source material. I like that I’ve learned how to set it up for proper movie REFERENCE playback, and from there, I just use some of the new Denon AVR tricks to adjust a bit for music sources.

Thanks again, you have done a lot of work which should be acknowledged!
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Took me two days, but I made it to the end of the article! Excellent work, incredibly comprehensive. Sure there is a lot of repeat information, but I understand why. Should be required reading for anyone interested in learning about subwoofers, all in one place. Been enjoying my Rythmik F12G for 10 years now, perfect for a small apartment, with the purchase of a new Denon 3500 AVR, I wanted to make sure I relearned all that I forgot, so I could choose the the right settings before running the latest Audyssey XT32. Your immense research and article was great in confirming what I’m doing here. Though I will say I’m still a bit confused about The Audyssey trim level debate between your more updated information versus the now older Audyssey setup thread which I reread as well. With my gain control knob at about 1:00 clock on the dial, I get the same results I did 10 years ago, “-3.5 dB”. Living in a small apartment does not allow me to even consider boosting my subwoofer manually, though I wish at times I could. Music formats are so all over the place, my sub can sound too intense or too tame depending on source material. I like that I’ve learned how to set it up for proper movie REFERENCE playback, and from there, I just use some of the new Denon AVR tricks to adjust a bit for music sources.

Thanks again, you have done a lot of work which should be acknowledged!
Thank you very much for the post! I appreciate it, and am very glad that the Guide was helpful to you. I hope that what I wrote about trim levels wasn't too confusing. Section VI does explain how the gain/trim thinking on the Audyssey thread, and elsewhere, has evolved since the Audyssey FAQ was originally written. Keeping trim levels negative is a good idea with any make of AVR's, and not just those that use Audyssey.

The bottom line, in your case, is that if you are getting a subwoofer trim setting of -3.5, you should be just fine. The -5 recommendation is just a guideline, and not a hard threshold that can't be crossed. But, if you were ever in a position to add subwoofer boost, it would be a good idea to use the gain control on your sub to do it. Or, you could always calibrate with your sub gain at 2:00, and start with a lower trim level, if you ever wanted to be able to add more subwoofer boost with your AVR remote.

Regards,
Mike
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GUIDE TO SUBWOOFER CALIBRATION AND BASS PREFERENCES

* The Guide linked above is a comprehensive guide to Audio & HT systems, including:
Speaker placements & Room treatments; HT calibration & Room EQ; Room gain; Bass
Preferences; Subwoofer Buyer's Guide: Sealed/ported; ID subs; Subwoofer placement.
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post #1122 of 1404 Old 02-26-2019, 06:17 PM
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Hi Morgan,

You are very welcome! The app wouldn't be able to help with the problem that you are describing. It allows users to make some adjustments, after the fact, to the frequency response; and it allows users to limit the frequency response to be EQed. But, the Audyssey program, working in conjunction with your AVR, sets crossovers based on what the Audyssey microphone "hears".

Based on your description, it sounds to me as if your Audyssey microphone is not functioning correctly. I would buy a replacement microphone and try that. Replacement microphones can be found on Amazon. The color doesn't matter, as the mics are generic. Just make sure that you are matching the same general type of microphone, such as the tower type that points up. I believe that there is an example listed in the Audyssey FAQ, linked in my signature.

Regards,
Mike
Thank you for your analysis and recommendations. After I submitted my post on Saturday I ended-up listening to quite a bit of music, mostly 2-channel, but a bit of 5.1, too, some heavy bass, some not so much, and watched a movie. Despite the cross-over settings, I thought it sounded pretty good with all cross-overs set manually to 80. I found myself wondering if the front channels were really being rolled-off below 250. The next morning I ran a shake and rattle sweep and 2-channel test tones from just above 250 to below 80, with a Radio Shack SPL metre. The levels went up and down a bit, but seemed pretty consistent the whole way. Maybe, I'm measuring the wrong thing, or something.
Anyway, after that I read your reply to my post, suggesting that the mic that came with the 8500 was faulty, and decided to try re-running Audyssey with the mic from my 3808, they are both tower types. Had been thinking about doing it, anyway, as the sub had ended-up at -10.5 and it seemed like the conventional wisdom was to have it more -5.
I started the calibration with the old mic plugged in, went to the sub level matching part of it and discovered that Audyssey was asking me lower the sub's gain more then it had before, -20 now being roughly equal to -14 from before. I backed out, plugged the 8500's mic in and ran it again, it's results were the same as it had always been. Backed out again, plugged in the mic from the 3808, and ran a full calibration. The results for the cross-overs were FR 150, C 80, S 40, SB 150, FH 40. That looks familiar and may be close to what I used to get with the 3808 (no FH, of course). I hadn't specifically been noticing the channel trims with the previous times running the calibration, but think the ones this time were less extreme.
With this last calibration the 8500 probably sounds more like my old 3808 than it had before. Also, the FH speakers blended in better and are substantially less harsh then before, I have still found myself turning them off, but less often.
With my previous calibrations of the 8500 I had always ended-up with critical listening levels of -10 to -5 for movies and -20 to -10 for music, which was similar to what it was with the 3808. This time I'm heading more into the 0.0 range for movies/TV, and similar increase for music.
Today I finally had a chance to look at the Audyssey FAQ, it said that the mic that came with the 3808 is not compatible with the 8500. I'm not sure what not compatible means here, obviously it did work with the program.
Thank you,
Morgan.
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post #1123 of 1404 Old 02-26-2019, 08:06 PM
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Originally Posted by internet seeker View Post
This is amazing. Great information.

I've been trying to get better bass in my system. I have a Denon 2310ci AVR, and engery RC speakers (RC-10's for FL/FR, RC-LCR center, Veritas mini for surround, and ESW-V10 for the sub). I ran Audessey (with the volume control on the sub at 50%) and Audessey set my SW channel level at -9.0. Crossovers are at 80 for center, 90 for FL/FR, and 100 for surrounds. I get very little bass and certainly no vibrating bass in movie soundtracks (tested a good one last night after reading a lot of your sticky: where Ky-Lo Ren is introduced and he makes a shot stick in mid air and Po is walked past that blaster).

I increased the SW channel level in the AVR from -9.0 to +4.0. I like the sound much, much better. After reading your guide, I note the suggestion to keep the AVR channel level to -5.0 and adjust the gain on the sub. I don't have a gain control on my sub, just a volume level. So, I was thinking of putting the AVR channel level at -5.0 and then increasing the volume on the sub, but that doesn't keep my sub volume relative to the other sounds (which is what the gain control does, from my reading of the sticky here).

So - if you don't have gain control on the sub, are there other suggestions or do I just do as proposed above?

P.S. - I have DEQ on, trying Audessy-Flat curve right now, and Dynamic Volume off.
Those two, should be the same. Just name differently

Honestly, you should not expect shaking bass from your sub;
https://hometheaterreview.com/energy...ofer-reviewed/
After all, it is only a 10" driver, the review is made to reflect other 10" sub. So sorry for the bad news.

If you want to feel the bass, I suggest you get some TT (Tactile Transducers) for your situation;
https://www.avsforum.com/forum/113-s...ual-guide.html


Ray
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I have Calibrated the Trinnov with a 7.4.4 setup. I have created a Target Curve too. I am using bass management and set the crossover to 90hz for all the subs and High pass filter of 90hz for all other speakers.

I had to increase the gain level on the subwoofers because the SPL was very less. After increasing the gain level the bass is distorted. I believe this can be taken care by a third party software like REW which will generate IIR and FIR Filters which can then be applied to Trinnov Channels.

So, to summarize I have to first calibrate my system with Trinnov, Then Increase the gain level of the subwoofers and calibrate them with third party software like spectraplus, Acourate or REW to generate the necessary filters and input these filter values into the Trinnov.

Please tell me if this is correct. Which Software would you recommend for the sole purpose of calibrating Subwoofer i.e. spectraplus, Acourate or REW.

Regards,

Rohit Bhargava
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post #1125 of 1404 Old 02-27-2019, 05:41 AM - Thread Starter
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Originally Posted by internet seeker View Post
This is amazing. Great information.

I've been trying to get better bass in my system. I have a Denon 2310ci AVR, and engery RC speakers (RC-10's for FL/FR, RC-LCR center, Veritas mini for surround, and ESW-V10 for the sub). I ran Audessey (with the volume control on the sub at 50%) and Audessey set my SW channel level at -9.0. Crossovers are at 80 for center, 90 for FL/FR, and 100 for surrounds. I get very little bass and certainly no vibrating bass in movie soundtracks (tested a good one last night after reading a lot of your sticky: where Ky-Lo Ren is introduced and he makes a shot stick in mid air and Po is walked past that blaster).

I increased the SW channel level in the AVR from -9.0 to +4.0. I like the sound much, much better. After reading your guide, I note the suggestion to keep the AVR channel level to -5.0 and adjust the gain on the sub. I don't have a gain control on my sub, just a volume level. So, I was thinking of putting the AVR channel level at -5.0 and then increasing the volume on the sub, but that doesn't keep my sub volume relative to the other sounds (which is what the gain control does, from my reading of the sticky here).

So - if you don't have gain control on the sub, are there other suggestions or do I just do as proposed above?

P.S. - I have DEQ on, trying Audessy-Flat curve right now, and Dynamic Volume off.

Hi,

Thank you for the compliment! For some reason, a couple of the recent posts weren't visible on my computer yesterday, and I missed yours. First, Darth is correct that the "volume" control on your sub is the gain control. The term gain control is technically correct, but many sub makers just call it a volume control. Your plan to turn up your gain control, and turn down your AVR trim, is the right thing to do.

As Darth also noted, there is a practical limit to what that subwoofer can produce, but if it sounds better since you turned it up louder, then mission accomplished. If you ever decide that you want more overall bass than your current subwoofer can produce, I would get a more powerful subwoofer, before I added tactile transducers to my system, but that is a matter of personal preference.

Despite the strong emphasis on this in the Guide, the whole issue of adding volume to subwoofers remains confusing at times. Audyssey's job is to make all of the transducers (speakers and subwoofers) in an audio system play the same volume level at the main listening position. That's Audyssey's job, but that's not our job. Our job is to make our bass sound the way we want it to, with any given content, on any given day. In order to do that, we should not hesitate to increase, or decrease, our subwoofer volume in accordance with our personal preference at that moment.

The whole idea behind Audyssey, or any other system of automated room EQ, is to improve the overall quality of the sound in our room, by improving the room/speaker interaction. But, we always get to decide what sounds good to us, and our various settings, including the subwoofer volume, are the tools we use to make things sound the way we really want them to. Guidelines, such as those offered in the Guide, help us to achieve our personal listening objectives. But, in the end, our ears determine when we have actually accomplished those objectives.

Regards,
Mike
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GUIDE TO SUBWOOFER CALIBRATION AND BASS PREFERENCES

* The Guide linked above is a comprehensive guide to Audio & HT systems, including:
Speaker placements & Room treatments; HT calibration & Room EQ; Room gain; Bass
Preferences; Subwoofer Buyer's Guide: Sealed/ported; ID subs; Subwoofer placement.
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Originally Posted by galaxyluv View Post
I have Calibrated the Trinnov with a 7.4.4 setup. I have created a Target Curve too. I am using bass management and set the crossover to 90hz for all the subs and High pass filter of 90hz for all other speakers.

I had to increase the gain level on the subwoofers because the SPL was very less. After increasing the gain level the bass is distorted. I believe this can be taken care by a third party software like REW which will generate IIR and FIR Filters which can then be applied to Trinnov Channels.

So, to summarize I have to first calibrate my system with Trinnov, Then Increase the gain level of the subwoofers and calibrate them with third party software like spectraplus, Acourate or REW to generate the necessary filters and input these filter values into the Trinnov.

Please tell me if this is correct. Which Software would you recommend for the sole purpose of calibrating Subwoofer i.e. spectraplus, Acourate or REW.

Regards,

Rohit Bhargava

Hi Rohit,

I had told you before that I wouldn't be able to help you very much with your Trinnov questions, and I am repeating that again now. Perhaps there is a Trinnov owners thread you can post on. There are two components to improving your sound quality. One component is to measure the frequency response to determine where the problem lies. I have already recommended that you use REW for that, and I directed you to the REW thread where you can get good technical assistance.

The second component to improving your sound quality is to make changes to your sound, once your measurements have indicated where the problems lie. The measurement equipment you use won't actually change the sound. To change the sound you have measured, you will need something like a miniDSP HT, as I also noted in my previous post to you.

You need to read what I am saying to you more carefully, and understand that there are two separate components to the problem-solving process. Measuring the frequency response with REW = problem identification. Making specific changes to the frequency response with something like a miniDSP = problem solution. Based on what you have said, so far, you will need to do both of those things.

As I also noted earlier, if it were my audio system, I would only operate the three PB16's. They will integrate much better with each other than they will with the Velodyne. And, you can always sell the Velodyne and buy a fourth PB16 if you want to. Making dissimilar subs play well together takes some knowledge and some effort. And, you will have to acquire that knowledge for yourself, if this is something you are determined to try.

This is really as far as I can go in helping you right now! Good luck!

Regards,
Mike
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GUIDE TO SUBWOOFER CALIBRATION AND BASS PREFERENCES

* The Guide linked above is a comprehensive guide to Audio & HT systems, including:
Speaker placements & Room treatments; HT calibration & Room EQ; Room gain; Bass
Preferences; Subwoofer Buyer's Guide: Sealed/ported; ID subs; Subwoofer placement.

Last edited by mthomas47; 02-27-2019 at 06:07 AM.
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post #1127 of 1404 Old 02-27-2019, 06:16 AM
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Originally Posted by darthray View Post
Those two, should be the same. Just name differently

Honestly, you should not expect shaking bass from your sub;
https://hometheaterreview.com/energy...ofer-reviewed/
After all, it is only a 10" driver, the review is made to reflect other 10" sub. So sorry for the bad news.

If you want to feel the bass, I suggest you get some TT (Tactile Transducers) for your situation;
https://www.avsforum.com/forum/113-s...ual-guide.html


Ray
PHEW! I had read this and was worried that I wouldn't get a relative change:

"A gain control and a volume control are the same thing---right? No. While adjusting them can result in similar results(increase or decrease in volume) the gain control functions differently. A volume control adjusts the output levels. A gain control adjust the output levels *relative* to the input levels. That is an important distinction."

No need for TT for me. I like it so much better now that it is adjusted.


Quote:
Originally Posted by mthomas47 View Post
Hi,

Thank you for the compliment! For some reason, a couple of the recent posts weren't visible on my computer yesterday, and I missed yours. First, Darth is correct that the "volume" control on your sub is the gain control. The term gain control is technically correct, but many sub makers just call it a volume control. Your plan to turn up your gain control, and turn down your AVR trim, is the right thing to do.

As Darth also noted, there is a practical limit to what that subwoofer can produce, but if it sounds better since you turned it up louder, then mission accomplished. If you ever decide that you want more overall bass than your current subwoofer can produce, I would get a more powerful subwoofer, before I added tactile transducers to my system, but that is a matter of personal preference.

Despite the strong emphasis on this in the Guide, the whole issue of adding volume to subwoofers remains confusing at times. Audyssey's job is to make all of the transducers (speakers and subwoofers) in an audio system play the same volume level at the main listening position. That's Audyssey's job, but that's not our job. Our job is to make our bass sound the way we want it to, with any given content, on any given day. In order to do that, we should not hesitate to increase, or decrease, our subwoofer volume in accordance with our personal preference at that moment.

The whole idea behind Audyssey, or any other system of automated room EQ, is to improve the overall quality of the sound in our room, by improving the room/speaker interaction. But, we always get to decide what sounds good to us, and our various settings, including the subwoofer volume, are the tools we use to make things sound the way we really want them to. Guidelines, such as those offered in the Guide, help us to achieve our personal listening objectives. But, in the end, our ears determine when we have actually accomplished those objectives.

Regards,
Mike
Mike - again, this guide helped me to actually ^start^ understanding my sound system. Really informative. I got my start with energy speakers and denon avr from batpig. Thanks community!

Glad that gain and volume are the same
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post #1128 of 1404 Old 02-27-2019, 07:15 AM
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Originally Posted by galaxyluv View Post
I have Calibrated the Trinnov with a 7.4.4 setup. I have created a Target Curve too. I am using bass management and set the crossover to 90hz for all the subs and High pass filter of 90hz for all other speakers.

I had to increase the gain level on the subwoofers because the SPL was very less. After increasing the gain level the bass is distorted. I believe this can be taken care by a third party software like REW which will generate IIR and FIR Filters which can then be applied to Trinnov Channels.

So, to summarize I have to first calibrate my system with Trinnov, Then Increase the gain level of the subwoofers and calibrate them with third party software like spectraplus, Acourate or REW to generate the necessary filters and input these filter values into the Trinnov.

Please tell me if this is correct. Which Software would you recommend for the sole purpose of calibrating Subwoofer i.e. spectraplus, Acourate or REW.

Regards,

Rohit Bhargava
There is a Trinnov thread that they may be able to help you at.
https://www.avsforum.com/forum/86-ul...l#post57619278
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post #1129 of 1404 Old 02-27-2019, 01:58 PM
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Quote:
Originally Posted by galaxyluv View Post
I have Calibrated the Trinnov with a 7.4.4 setup. I have created a Target Curve too. I am using bass management and set the crossover to 90hz for all the subs and High pass filter of 90hz for all other speakers.

I had to increase the gain level on the subwoofers because the SPL was very less. After increasing the gain level the bass is distorted. I believe this can be taken care by a third party software like REW which will generate IIR and FIR Filters which can then be applied to Trinnov Channels.

So, to summarize I have to first calibrate my system with Trinnov, Then Increase the gain level of the subwoofers and calibrate them with third party software like spectraplus, Acourate or REW to generate the necessary filters and input these filter values into the Trinnov.

Please tell me if this is correct. Which Software would you recommend for the sole purpose of calibrating Subwoofer i.e. spectraplus, Acourate or REW.

Regards,

Rohit Bhargava
Hi Rohit,
You'll get more Trinnov specific advise on the Trinnov Altitude thread.
https://www.avsforum.com/forum/86-ul...l#post57619278

Here's my take on it as a long-time Trinnov user.

Integrating multiple subs, dealing with gain structure, and determining the order of PEQ vs. the Altitude's acoustic correction with the Trinnov Optimizer isn't a trivial subject. Typically you integrate the subs together, possibly with assistance from a multi-sub optimization tool like MSO, then consider running PEQ on the summated sub response with REW's Auto EQ if necessary as an additional step (against the appropriate target curve you want), and then apply those filters before running Trinnov Optimizer. Their Optimizer is IIR for the subs, by the way, but you can't directly enter in externally measured IIR filter settings for just subs. You can draw a target curve and experiment with octave resolution for the acoustic correction (an advanced topic about how/when to do so), but that's a blunt instrument approach for low bass response unless you're lucky or skilled.

After you run Optimizer you might want to remeasure with REW or some other software (OmniMic, Audiotools) on the post-EQ response and measure SPL levels against other speakers to make sure you've got the speaker/sub FR working smoothly with appropriate DB levels.

Since you've got an Altitude 32, I'm guessing you don't need to use something like an external MiniDSP box unless you're low on channels. But your best bet would be to go to your dealer and get some hands-on consulting advice about integration. Failing that, unless you want to spend a lot of time doing trial and error yourself, you can try to contact someone like Curt Hoyt (Curt_trinnov) or Adam Pelz (appelz) here on AVS if you're in the US. Curt can work with you remotely over VNC; Adam is a hands-on, in-person kind of guy but both are at the top of the field for certified Trinnov calibration.

Caveats: I'm assuming you're in the US. If you're not, you might get remote assistance but you'll have to contact Trinnov or your dealer for some calibration assistance potentially. And if you're using a late model Altitude 32 with the beta software that has the Calibration Wizard as the basis of your experience with the Altitude, my advice is definitely into "there be dragons" territory, and you'll definitely want some outside help.
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Last edited by sdrucker; 02-27-2019 at 07:07 PM.
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post #1130 of 1404 Old 02-27-2019, 05:43 PM
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There is a Trinnov thread that they may be able to help you at.
https://www.avsforum.com/forum/86-ul...l#post57619278
Thanks for providing a link to the OP
A more specific thread about the Trinnov, since fewer members use that calibration system.

Quote:
Originally Posted by sdrucker View Post
Hi Rohit,
You'll get more Trinnov specific advise on the Trinnov Altitude thread.
https://www.avsforum.com/forum/86-ul...l#post57619278

Here's my take on it as a long-time Trinnov user.

Integrating multiple subs, dealing with gain structure, and determining the order of PEQ vs. the Altitude's acoustic correction with the Trinnov Optimizer isn't a trivial subject. Typically you integrate the subs together, possibly with assistance from a multi-sub optimization tool like MSO, then consider running PEQ on the summated sub response with REW's Auto EQ if necessary as an additional step (against the appropriate target curve you want), and then apply those filters before running Trinnov Optimizer. Their Optimizer is IIR for the subs, by the way, but you can't directly enter in externally measured IIR filter settings for just subs. You can draw a target curve and experiment with octave resolution for the acoustic correction (an advanced topic about how/when to do so), but that's a blunt instrument approach for low bass response unless you're lucky or skilled.

After you run Optimizer you might want to remeasure with REW or some other software (OmniMic, Audiotools) on the post-EQ response and measure SPL levels against other speakers to make sure you've got the speaker/sub FR working smoothly with appropriate DB levels.

Since you've got an Altitude 32, I'm guessing you don't need to use something like an external MiniDSP box unless you're low on channels. But your best bet would be to go to your dealer and get some hands-on consulting advice about integration. Failing that, unless you want to spend a lot of time doing trial and error yourself, you can try to contact someone like Curt Hoyt (Curt_trinnov) or Adam Pelz (appelz) here on AVS if you're in the US. Curt can work with you remotely over VNC; Adam is a more hands-on, in-person kind of guy but both are at the top of the field for certified Trinnov calibration.

Caveats: I'm assuming you're in the US. If you're not, you might get remote assistance but you'll have to contact Trinnov or your dealer for some calibration assistance potentially. And if you're using a late model Altitude 32 with the beta software that has the Calibration Wizard as the basis of your experience with the Altitude, my advice is definitely into "there be dragons" territory, and you'll definitely want some outside help.

Also thanks for providing the link and your knowledge to the OP, about the Trinnov

Quote:
Originally Posted by mthomas47 View Post
Hi Rohit,

I had told you before that I wouldn't be able to help you very much with your Trinnov questions, and I am repeating that again now. Perhaps there is a Trinnov owners thread you can post on. There are two components to improving your sound quality. One component is to measure the frequency response to determine where the problem lies. I have already recommended that you use REW for that, and I directed you to the REW thread where you can get good technical assistance.

The second component to improving your sound quality is to make changes to your sound, once your measurements have indicated where the problems lie. The measurement equipment you use won't actually change the sound. To change the sound you have measured, you will need something like a miniDSP HT, as I also noted in my previous post to you.

You need to read what I am saying to you more carefully, and understand that there are two separate components to the problem-solving process. Measuring the frequency response with REW = problem identification. Making specific changes to the frequency response with something like a miniDSP = problem solution. Based on what you have said, so far, you will need to do both of those things.

As I also noted earlier, if it were my audio system, I would only operate the three PB16's. They will integrate much better with each other than they will with the Velodyne. And, you can always sell the Velodyne and buy a fourth PB16 if you want to. Making dissimilar subs play well together takes some knowledge and some effort. And, you will have to acquire that knowledge for yourself, if this is something you are determined to try.

This is really as far as I can go in helping you right now! Good luck!

Regards,
Mike
Big +1, I would also do the same
Integrating multiple subs can be sometime difficult enough, no need to make-it even more difficult. With one sub that is different than the first three.


Ray
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Last edited by darthray; 02-27-2019 at 05:58 PM.
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post #1131 of 1404 Old 03-02-2019, 01:45 PM
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Hi,

Seeing a graph may help a little in understanding how bad the situation is. But, if the frequency response is all over the place, I don't really think that seeing the graph will help in diagnosing the problem, or in suggesting a solution. This doesn't sound as simple as cancellation at the crossover to the mains, or something like that.

Is the visible graphed problem matched by an audible problem? Sometimes, REW is not our friend if we can't actually hear the problems it shows us. In any event, I suspect that you are just going to have to keep experimenting. If you haven't already tried Audyssey by itself, I would probably do that. Afterwards, I might try to use the Dayton to fine-tune the Audyssey result. (In theory, I believe that 8ms of delay should be enough, at least below about 80Hz.)

I understand that you don't want to move the subs, but if you can get one of the subs to work well by itself, then you may want to consider stacking them, or placing them side-by-side. Other than to add 6db more SPL (averaged over the subs' passband) the biggest reason to have multiple subs is to improve the frequency response. But, if dual subs degrade the FR instead, then it may be time to rethink the subwoofer placements. Getting speaker stands, and moving the subs either very close together, or much more widely separated (perhaps on different walls) may have to be an option, if all else fails.

Regards,
Mike
Finally got around to taking a few measurements today. I actually redid my calibration for both subs, this time using the MiniDSP EQ template within REW. (Not sure if that is relevant to issue). No Audyssey, stereo mode, no DEQ, etc. The levels on the subs are not matched very well, even though I used the SPL meter in REW to match them when getting started....

At any rate:
Left sub after calibration (I had the crossover on the AVR at 80hz for all measurements):


Right sub:


Combined output of both subs:


Finally, all three together:


How you guys are getting ruler flat sub outputs in beyond me. I will say the 4 x 18" subs in the theater are much flatter......it's all a mystery to me.... lol.

I will be getting new woofers and mids for my main L&R speakers this week (essentially Pioneer CS-88 boxes with all new guts), so after I install those, I will re-run everything again. BTW, I used all 10 bands of PEQ per sub, so I ran out of EQ bands before everything got flat. I always use the REW EQ feature, however this time I did not use the "House Curve" feature, because I don't think I fully understand it, and when I do, I get some odd EQ settings.....no flatter.

EDIT: I should point out that the left sub has this driver:https://www.parts-express.com/dayton...8-ohm--295-445 and the right sub has this driver: https://www.parts-express.com/dayton...oofer--295-488. They did have the same HF driver, but I replaced the right one when it had voice coil rubbing sound, only to find out that the right sub had a defective speaker cable. Chances are the original driver is fine.....oh well, that another story.

EDIT 2: I also forgot to mention the right sub ended up being set to 180 deg phase and the left at 0 deg phase. This makes sense to me, as the subs are each firing outboard (just the way they fit best in the living room). Having one 180 deg to the other produced the flattest response together.
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Last edited by legierk; 03-02-2019 at 02:26 PM.
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post #1132 of 1404 Old 03-04-2019, 09:28 AM
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Finally got around to taking a few measurements today. I actually redid my calibration for both subs, this time using the MiniDSP EQ template within REW. (Not sure if that is relevant to issue). No Audyssey, stereo mode, no DEQ, etc. The levels on the subs are not matched very well, even though I used the SPL meter in REW to match them when getting started....

How you guys are getting ruler flat sub outputs in beyond me. I will say the 4 x 18" subs in the theater are much flatter......it's all a mystery to me.... lol.

I will be getting new woofers and mids for my main L&R speakers this week (essentially Pioneer CS-88 boxes with all new guts), so after I install those, I will re-run everything again. BTW, I used all 10 bands of PEQ per sub, so I ran out of EQ bands before everything got flat. I always use the REW EQ feature, however this time I did not use the "House Curve" feature, because I don't think I fully understand it, and when I do, I get some odd EQ settings.....no flatter.

EDIT: I should point out that the left sub has this driver:https://www.parts-express.com/dayton...8-ohm--295-445 and the right sub has this driver: https://www.parts-express.com/dayton...oofer--295-488. They did have the same HF driver, but I replaced the right one when it had voice coil rubbing sound, only to find out that the right sub had a defective speaker cable. Chances are the original driver is fine.....oh well, that another story.

EDIT 2: I also forgot to mention the right sub ended up being set to 180 deg phase and the left at 0 deg phase. This makes sense to me, as the subs are each firing outboard (just the way they fit best in the living room). Having one 180 deg to the other produced the flattest response together.

I assume since the graphs are labeled "right sub" and "left sub" that both subs are up front, would that be correct? As you probably know, that configuration is not the best for mode smoothing.

Which MiniDSP are you using? Make sure you are choosing the correct EQ preset in REW; HD or non-HD.

Are you EQ'ing the subs individually? The subs should be EQ'ed together "as one".

If you are using all 10 bands of PEQ, I can guarantee that you are using way too many filters. Looking at your combined response (albeit, post-EQ), you should only need 1 or 2 filters to get it close to flat...however, since that large dip at 57hz is present for both subs individually and in the combined response, it is a room mode and can only be fixed by different sub placement or more subs. Can you post a screenshot of your pre-EQ combined response as well as your current EQ filters?

If you are using a MiniDSP, there is no need to adjust phase on the subs. You can properly time-align them with the Impulse Response in REW using the delays in the MiniDSP.
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post #1133 of 1404 Old 03-04-2019, 07:06 PM
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Originally Posted by Alan P View Post
I assume since the graphs are labeled "right sub" and "left sub" that both subs are up front, would that be correct? As you probably know, that configuration is not the best for mode smoothing.

Which MiniDSP are you using? Make sure you are choosing the correct EQ preset in REW; HD or non-HD.

Are you EQ'ing the subs individually? The subs should be EQ'ed together "as one".

If you are using all 10 bands of PEQ, I can guarantee that you are using way too many filters. Looking at your combined response (albeit, post-EQ), you should only need 1 or 2 filters to get it close to flat...however, since that large dip at 57hz is present for both subs individually and in the combined response, it is a room mode and can only be fixed by different sub placement or more subs. Can you post a screenshot of your pre-EQ combined response as well as your current EQ filters?

If you are using a MiniDSP, there is no need to adjust phase on the subs. You can properly time-align them with the Impulse Response in REW using the delays in the MiniDSP.
Thanks for the response and help Alan...and as Mike has given his thumbs up, I'll take it as gospel.

Yes, both subs are up front, under the main LR speakers. Equidistant from the sidewalls. Understand this may not be optimum. I would like to try to get it close in these positions before I resort to moving them, however, for aesthetic reasons mainly (WAF).

I am using the Dayton Audio DSP-408. Why? Just to be different? LOL. It works well, just does not have any preset within REW (meaning, I can't "choose" it as my EQ in REW. I either "choose" Generic or MiniDSP. Either way, I just transfer (manually) the PEQ settings REW spits out to the DSP-408. This is why I asked in either this forum, or another (can't remember) if anyone knew of an optimum EQ to use within REW (when using the Dayton DSP-408).

I have been EQing the subs individually. In the theater room, with 4 x 18"s, I used a BFD for PEQ. This allows me to EQ each one, THEN use a few filters "linked" to EQ them together. This works out well in the theater room, even with an old school PEQ like the BFD. However, the DSP-408 does not allow this. I CAN "link" any of the channels together though, it is just either/or, not both. So, if the instructions are to EQ them both together (combined output), I will link the PEQ filters for inputs 1 and 2. This will just duplicate the PEQ settings of one channel to the other. (I just always assumed since my AVR has 2 sub outs, the DSP has 4 inputs and 8 outputs, I should keep the subs separate the entire chain. Maybe I am overthinking it.)

I understand using a minimum number of filters is preferable, however, each time I get an EQ solution from REW, I run another sweep, and then it will give me another set of filters, etc. trying to get the curve flat (This goes on until I run out of filters, which in the case of the DSP-408, is 10). I do have REW "Flatness Target" set to 2db...it defaults to 3db, so I figured I would outsmart it! LOL. Should I use 2db or ….?

Is there a tutorial on using impulse response within REW to time align? Note that the Dayton DSP-408 has a maximum of 8ms delay ( I saw a chart once that converted this to feet, not sure where I saw it though.) Many have said the 8ms is not enough delay so forego the DSP-408 for MiniDSP. I DID use the delay feature however, knowing that one sub is actually 1 ft closer to the MLP (UMIK-1 mic), I added delay to the nearest sub until the combined output was the flattest (in my case the delay turned out to be 2ms for the right sub). I realize this is an unscientific way to do this, but I do not know how to use the impulse response feature of REW.

I attached a screenshot of the DSP-408 Windows software interface. This is not the PC I use, so no files are present. They are on my wife's laptop in the living room and I can get that info if it would help. (This is just the defaults for the DSP-408. You can put any frequency in any of the 10 Freq boxes in any order. All mine are below 80hz of course. Filter number 1 has the capability to be a low shelf filter, which I have played with for 20hz.....filter 10 has the ability to be a high shelf filter....I have used neither in the above graphs.)



Thanks for all the assistance. Keith
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post #1134 of 1404 Old 03-04-2019, 07:45 PM
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Originally Posted by legierk View Post
Thanks for the response and help Alan...and as Mike has given his thumbs up, I'll take it as gospel.

Yes, both subs are up front, under the main LR speakers. Equidistant from the sidewalls. Understand this may not be optimum. I would like to try to get it close in these positions before I resort to moving them, however, for aesthetic reasons mainly (WAF).

I am using the Dayton Audio DSP-408. Why? Just to be different? LOL. It works well, just does not have any preset within REW (meaning, I can't "choose" it as my EQ in REW. I either "choose" Generic or MiniDSP. Either way, I just transfer (manually) the PEQ settings REW spits out to the DSP-408. This is why I asked in either this forum, or another (can't remember) if anyone knew of an optimum EQ to use within REW (when using the Dayton DSP-408).

I have been EQing the subs individually. In the theater room, with 4 x 18"s, I used a BFD for PEQ. This allows me to EQ each one, THEN use a few filters "linked" to EQ them together. This works out well in the theater room, even with an old school PEQ like the BFD. However, the DSP-408 does not allow this. I CAN "link" any of the channels together though, it is just either/or, not both. So, if the instructions are to EQ them both together (combined output), I will link the PEQ filters for inputs 1 and 2. This will just duplicate the PEQ settings of one channel to the other. (I just always assumed since my AVR has 2 sub outs, the DSP has 4 inputs and 8 outputs, I should keep the subs separate the entire chain. Maybe I am overthinking it.)

I understand using a minimum number of filters is preferable, however, each time I get an EQ solution from REW, I run another sweep, and then it will give me another set of filters, etc. trying to get the curve flat (This goes on until I run out of filters, which in the case of the DSP-408, is 10). I do have REW "Flatness Target" set to 2db...it defaults to 3db, so I figured I would outsmart it! LOL. Should I use 2db or ….?

Is there a tutorial on using impulse response within REW to time align? Note that the Dayton DSP-408 has a maximum of 8ms delay ( I saw a chart once that converted this to feet, not sure where I saw it though.) Many have said the 8ms is not enough delay so forego the DSP-408 for MiniDSP. I DID use the delay feature however, knowing that one sub is actually 1 ft closer to the MLP (UMIK-1 mic), I added delay to the nearest sub until the combined output was the flattest (in my case the delay turned out to be 2ms for the right sub). I realize this is an unscientific way to do this, but I do not know how to use the impulse response feature of REW.

I attached a screenshot of the DSP-408 Windows software interface. This is not the PC I use, so no files are present. They are on my wife's laptop in the living room and I can get that info if it would help. (This is just the defaults for the DSP-408. You can put any frequency in any of the 10 Freq boxes in any order. All mine are below 80hz of course. Filter number 1 has the capability to be a low shelf filter, which I have played with for 20hz.....filter 10 has the ability to be a high shelf filter....I have used neither in the above graphs.)



Thanks for all the assistance. Keith
Hi Keith

Correct me if I am wrong!
Sound like your Dayton Audio DSP-408, is all manual. Like my previous Velodyne SMS-1.
Manual tweaking is hard to achieve! Every time you a change a frequency, with a wide or narrow filter it will affect the frequencies next to-it to a certain extend.

Since I have no knowledge about REW. Someone like @Alan P do!
For the little knowledge that I know about the REW, you can see in real time what any change do for the overall sound response.
The reason many of us rely on Automatic System, and let the hardcore using a system like REW for tweaking
For the delay, in short. 1 foot equal 1ms, so if your other sub/s is more than 8 feet away from your MLP. You do not have enough delay, therefore out of phase (by how much depend of the distance required).

Just post some basic info.
Since my system/site, keep freezing on me
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post #1135 of 1404 Old 03-05-2019, 02:03 PM
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Originally Posted by legierk View Post
Thanks for the response and help Alan...and as Mike has given his thumbs up, I'll take it as gospel.

Yes, both subs are up front, under the main LR speakers. Equidistant from the sidewalls. Understand this may not be optimum. I would like to try to get it close in these positions before I resort to moving them, however, for aesthetic reasons mainly (WAF).

I am using the Dayton Audio DSP-408. Why? Just to be different? LOL. It works well, just does not have any preset within REW (meaning, I can't "choose" it as my EQ in REW. I either "choose" Generic or MiniDSP. Either way, I just transfer (manually) the PEQ settings REW spits out to the DSP-408. This is why I asked in either this forum, or another (can't remember) if anyone knew of an optimum EQ to use within REW (when using the Dayton DSP-408).
I as well do not know which REW preset you should use for your particular EQ...maybe ask the REW creator @JohnPM ??


Quote:
I have been EQing the subs individually. In the theater room, with 4 x 18"s, I used a BFD for PEQ. This allows me to EQ each one, THEN use a few filters "linked" to EQ them together. This works out well in the theater room, even with an old school PEQ like the BFD. However, the DSP-408 does not allow this. I CAN "link" any of the channels together though, it is just either/or, not both. So, if the instructions are to EQ them both together (combined output), I will link the PEQ filters for inputs 1 and 2. This will just duplicate the PEQ settings of one channel to the other. (I just always assumed since my AVR has 2 sub outs, the DSP has 4 inputs and 8 outputs, I should keep the subs separate the entire chain. Maybe I am overthinking it.)
AVRs with dual sub outputs do not EQ the subs individually. They set individual distances and trims, but they are EQ'ed as one. EQ'ing the subs separately is not an easy task and is best left to something like Multi-Sub Optimizer.


Quote:
I understand using a minimum number of filters is preferable, however, each time I get an EQ solution from REW, I run another sweep, and then it will give me another set of filters, etc. trying to get the curve flat (This goes on until I run out of filters, which in the case of the DSP-408, is 10). I do have REW "Flatness Target" set to 2db...it defaults to 3db, so I figured I would outsmart it! LOL. Should I use 2db or ….?
Are you saying that you EQ the response, run REW afterwards and then generate more filters? You should be generating all filters on a single measurement, apply the filters, re-measure and then tweak from there. Do not add filters that were generated by an already EQ'ed response.


Quote:
Is there a tutorial on using impulse response within REW to time align?
Here is an excellent guide by @AustinJerry :
Using MiniDSP 2x4 to Time-Align Multiple Subs on One Channel


Quote:
Note that the Dayton DSP-408 has a maximum of 8ms delay ( I saw a chart once that converted this to feet, not sure where I saw it though.)
1ms equals approximately 1.1 ft, but it's not as simple as that. You can't use the actual physical distance because processing in the sub amp will increase delay and that needs to be accounted for.


Quote:
Many have said the 8ms is not enough delay so forego the DSP-408 for MiniDSP. I DID use the delay feature however, knowing that one sub is actually 1 ft closer to the MLP (UMIK-1 mic), I added delay to the nearest sub until the combined output was the flattest (in my case the delay turned out to be 2ms for the right sub). I realize this is an unscientific way to do this, but I do not know how to use the impulse response feature of REW.
Since the difference is so slight, 8ms is more than enough with your current placement.


Here is a very good read by @Wayne A. Pflughaupt on Minimal EQ, Target Levels, and a Hard-Knee House Curve. I can guarantee that you are currently over-EQ'ing.

I would still like to see your pre-EQ frequency response from the combined subs.
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post #1136 of 1404 Old 03-05-2019, 02:22 PM
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Originally Posted by Alan P View Post
I as well do not know which REW preset you should use for your particular EQ...maybe ask the REW creator @JohnPM ??




AVRs with dual sub outputs do not EQ the subs individually. They set individual distances and trims, but they are EQ'ed as one. EQ'ing the subs separately is not an easy task and is best left to something like Multi-Sub Optimizer.




Are you saying that you EQ the response, run REW afterwards and then generate more filters? You should be generating all filters on a single measurement, apply the filters, re-measure and then tweak from there. Do not add filters that were generated by an already EQ'ed response.




Here is an excellent guide by @AustinJerry :
Using MiniDSP 2x4 to Time-Align Multiple Subs on One Channel




1ms equals approximately 1.1 ft, but it's not as simple as that. You can't use the actual physical distance because processing in the sub amp will increase delay and that needs to be accounted for.




Since the difference is so slight, 8ms is more than enough with your current placement.


Here is a very good read by @Wayne A. Pflughaupt on Minimal EQ, Target Levels, and a Hard-Knee House Curve. I can guarantee that you are currently over-EQ'ing.

I would still like to see your pre-EQ frequency response from the combined subs.
Like Keith above, my two Velo (non-matching) subs are up front. I've been running wires through walls for speakers recently, so now I know that I have the ability to move the sub- just not sure where to move it yet. Depends on furniture purchase in the near future, and the WAF.

The good news is that while I was reassembling everything, it gave me the perfect chance to try the oft-mentioned sub crawl. My room is basically a 24'x20' square with hardwood floors and reflective surfaces throughout, and a 16-foot wide alcove at the front where the HT equipment sits. It's open in several places since it's our main living room, so I had to make do when setting up for Atmos. I had moved the sub all over, and a friend had suggested putting the subs near the receiver and cabinet and putting my L/R towers on the outside nearest the wall. It did look nice, but the bass suffered terribly.

After doing the sub crawl with some Prince music and the L/R/C disconnected, it became completely obvious to a non-audiophile like me that the front corners were by far the best place for the sub. It's as if it takes the whole living room floor (wood, with basement beneath) and turns it all into one huge reverberating surface! Big difference. So I connected the subs back, turned on some tunes, and sat back down at my work computer in the next room. After a few minutes, I actually had to go back to the receiver and turn DOWN the gain on the bass. Never thought I'd say that out loud on AVS... but that's what happened.

So thanks to all for the posts, the guide, the questions, and the replies - this has all made a big difference in my setup. Now I'm reading that the second sub should really be at the back, so that part will have to go on my HT todo list...
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Originally Posted by Photokid1970 View Post

After doing the sub crawl with some Prince music and the L/R/C disconnected, it became completely obvious to a non-audiophile like me that the front corners were by far the best place for the sub. It's as if it takes the whole living room floor (wood, with basement beneath) and turns it all into one huge reverberating surface! Big difference. So I connected the subs back, turned on some tunes, and sat back down at my work computer in the next room. After a few minutes, I actually had to go back to the receiver and turn DOWN the gain on the bass. Never thought I'd say that out loud on AVS... but that's what happened.
The room corners are actually one of the worst placements for the subs. A sub in a corner excites all of the room modes, which is why it sounded so loud to you. If you were to use REW to actually measure the subs, you would see that your response is probably quite uneven at your seating location. You would be doing yourself a favor by actually taking some measurements to assist in proper sub placement.
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post #1138 of 1404 Old 03-05-2019, 05:05 PM
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Curious. Every place I’ve ever lived with a sub, the corner was the best place in the room, with the highest output and lowest extension, and the best response before equalization (in fact, that’s what I see on your “My Setup” page with the individual pre-EQ measurements). After the inevitable peak and a few other minor issues were tamed with EQ, it sounded great.

Goes to show with subs “rules of thumb are nice,” but should always be checked because no two rooms are alike...

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Originally Posted by Wayne A. Pflughaupt View Post
Curious. Every place I’ve ever lived with a sub, the corner was the best place in the room, with the highest output and lowest extension, and the best response before equalization (in fact, that’s what I see on your “My Setup” page with the individual pre-EQ measurements). After the inevitable peak and a few other minor issues were tamed with EQ, it sounded great.

Goes to show with subs “rules of thumb are nice,” but should always be checked because no two rooms are alike...

Regards,
Wayne A. Pflughaupt
I agree than no two rooms are the same. I think the point I was trying to make is that placing subs by listening to music is not what I would recommend. Using a tool like REW will always produce better results.

Not sure I understand your reference to "My Setup". I don't have subs in the corners of my room.
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post #1140 of 1404 Old 03-05-2019, 06:16 PM
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I as well do not know which REW preset you should use for your particular EQ...maybe ask the REW creator @JohnPM ??

AVRs with dual sub outputs do not EQ the subs individually. They set individual distances and trims, but they are EQ'ed as one. EQ'ing the subs separately is not an easy task and is best left to something like Multi-Sub Optimizer.

Are you saying that you EQ the response, run REW afterwards and then generate more filters? You should be generating all filters on a single measurement, apply the filters, re-measure and then tweak from there. Do not add filters that were generated by an already EQ'ed response.

Here is an excellent guide by @AustinJerry :
Using MiniDSP 2x4 to Time-Align Multiple Subs on One Channel

1ms equals approximately 1.1 ft, but it's not as simple as that. You can't use the actual physical distance because processing in the sub amp will increase delay and that needs to be accounted for.

Since the difference is so slight, 8ms is more than enough with your current placement.

Here is a very good read by @Wayne A. Pflughaupt on Minimal EQ, Target Levels, and a Hard-Knee House Curve. I can guarantee that you are currently over-EQ'ing.

I would still like to see your pre-EQ frequency response from the combined subs.

Lots to take in here. I have some reading to do. Super busy at work this week. Expect some measurements as we get closer to the end of the week, when my schedule lightens up a bit. Thank you for the in depth insight on my issues. Keith
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