Axiom Home Page Forums General Discussion Home Theater my nightmare,

Well today was finally the day to set up my HT system, I hired a guy to run all the wires in the wall for the surrounds and the sub (which is placed in the back corner). Well, 5 minutes into installation, I hear a loud bang, go running it, and the idiot knocked over my M40ti while moving my entertainment center. There was a small nick in the veneer, but my real worry was the speaker itself. The guy hooked it up and all sounds well, but I am still nervous. The guy said the only potential problem would be if the voice coil came detachted and I would hear a scratchy noise, but so far the speaker sounds normal. Is there anything I should be listening for, any potential problems down the road because of this? Man, I am still pissed.

The guy finished the job and gave my 1/2 off the installation, hopefully I averted needing a new M40ti!!!

That aside, the system sounded great during my first DVD (The Matrix). The only problem (still) is sub calibration, I watched with all speakers to "small" and the sub volume at about 9 o'clock and all sounded great. However, music was boomy, too much bass. turn it down to for music and not enough oomph for HT. I tried the "large" setting crossed over at 55hz and volume at 8 o'clock, great for music not HT. Are the hopes of one setting and leaving it alone a pipe dream?

And lastly, what do some of you listen to HT at, tonight I had my Marantz at -10db, almost all the way up the master volume "bar" on my display, is that considered loud?

wow, this post got long, sorry for rambling

Hi Undecided5,

As long as the M40ti didn't fall over on its front baffle, it's unlikely there's any internal damage. Speakers are fairly hardy devices and can withstand a fair amount of physical abuse. Use your pink noise Dolby Digital alignment signal to ensure the tweeter and woofer are both working. Put your ear right up to the tweeter--the hiss should be smooth sounding.

Regarding your other post on alignment DVDs, the Sound&Vision Home Theater Tune-Up disc is much easier to use than the Avia disc, and less expensive as well. It has lots of excellent subwoofer/satellite calibration tests. Get it by all means, and the Radio Shack SPL meter (analog version), otherwise your settings will be all over the place. And yes, using the DVD and the meter, you should arrive at a subwoofer setting that will suit most movies and much of your music, apart from actual differences in the deep bass levels of the program sources. Those may vary quite a lot, but you can trim the sub volume when required.

Don't forget to experiment with subwoofer locations as well.

The S&V DVD also has plenty of video calibration tests to properly set up your TV monitor.

Regards,

thanks alan -

the M40ti fell on it's side and I cannot hear any problems, i played music for a few hours last night and all seems OK.

I am off the Barnes & Noble to get the S&V video today!

Hi,

If you want a few more tips on using the S&V Tune-Up DVD and subwoofer adjustment, go to axiomaudio.com/archives, and click on the AudioFile newsletter for August,2002.

Regards,

Un, sorry to hear about the speaker crash.
Hopefully all is well.

You seem to have come across the same bass sound that i did when using the speakers 'small' settings. I have found peace for both HT and music using the second method of setup with 'large' options in place.
However it sounds like you tried that and were still unsatisfied. This also happened to me the first time i was setting up my system and as Alan suggested, try a different placement for the subwoofer.
My original location was to the left of my listening area about 4 feet out but now the sub sits up front next to my m60s on the inside b/w the 2 speakers. (If i had put it on the outside of the m60 it would be sitting in a corner...too much boom again).
Positioning really can be important.

Alan,

Why do you specify the analog version of the Radio Shack SPL meter? The Radio Shack's in my area said they only have the digital one, so that is what I got.

Michael

RS no longer manufacture the analog version of the meter. The digital version works well just make sure that the response is set to slow or you will as Alan says have readings all over the place.

Copy of letter from owner of HSU on tuning that sub.


Hello, I thought I would share this info as it may help some
others.The Question was specific about tuning with my Yamaha
RX-V1000 but there is info for others in his responce also.
This is customer service!!
Question
I am trying to set up my Subwoofer with my Radio Shack SPL
Meter.
My Yamaha RXV-1000 receiver gives me choices of frequencies to
use to set it up Which do you recommend I use with the meter
to set my subwoofer?
Here are my Frequency choices. 35Hz, 39Hz, 44Hz, 50Hz, 56Hz,
63Hz, 70Hz, 79Hz, 88Hz, 99Hz, 111Hz, 125Hz, 140Hz,
157Hz,177Hz, 198Hz, 223Hz, 250Hz or WIDE.
I expect you will want me to use either Wide or one of the
lower choices here but not sure which? There was no choice for
the main & Surround speaker tone only LFE.
My speakers are set to 75db & I plan on setting the Subwoofer
to 85db.
I listen to Movies as well as music on my HT system. I am at
best a beginner & still learning. Tuning for me has been a
difficult experience. I started with my crossover set to 8
O’clock as you recommended. I have it now at the 9:30 position
& my volume at the 10 O’clock position.& Set for max
extension. So far this seems to be the best place for all
around listening.



Responce#1 from Po Hsu:
Are those test frequencies or crossover frequencies? Sounds
more like crossover frequencies. Can you FAX over the pages
that describes it? FAX to (714)666-9261.
You should not be setting the subwoofer 10 dB louder than the
main speakers. I would go for at most 3 dB louder. If the
levels can be set differently for each source, I would go for
3 dB higher for video sources compared to audio sources. I set
mine for flat response for music (75 dB for mains and sub),
and 3 dB hotter for the sub for HT.


Responce#2 from Po Hsu:
Got your FAX. I stand corrected. Its interesting that they
included a narrow bandwidth pink noise for testing the in-room
response. That is great. What you need to do is
1. Set the mains, center and surround to small and yes to
subwoofer.
2. Set the crossover switch on the VTF-2 to out.
3. Play the test tones from 35 Hz up to 88 Hz and see what
readings you get for each frequency. If the measurements are
fairly even, skip to step 5.
4. If the upper frequencies are too high, set the VTF-2
crossover to in and adjust the frequency control to get the
flattest response from 35 to 88 Hz.
5. Set the test frequency to wide. Adjust level of subwoofer
to get about 3 dB higher reading on the SPL meter than the
main speakers.
6. Switch to a stereo source (CD, for example). If you can set
the subwoofer level separately for each source, set the
subwoofer level 3 dB less than what you have set for the home
theater sources.
Too bad that Yamaha still refuse to give the user the
flexibility to select different crossover frequencies. You
stand a much better chance of getting a flatter response and
make better use of your speakers if they allow you to choose
the crossover frequency as well as the test tones. With your
large main speakers, I would have crossed over at 50 Hz or so.

An alternative is
1. Set the mains to large, and select to send all bass to both
the mains and the sub. Set the subwoofer level on the Yamaha
to -3 dB.
2. Set the crossover switch on the VTF-2 to in.
3. Play the test tones from 35 Hz up to 88 Hz and see what
readings you get for each frequency.
4. Adjust the frequency control and level control of the VTF-2
to get the flattest response from 35 to 88 Hz.
5. Set the subwoofer level to 0 dB for video sources, and - 3
dB for audio sources..


If you would like to view the entire thread as this person was having the same problem as you:

http://www.hometheaterforum.com/htforum/showthread.php?s=&threadid=42022


From the web site:

The VTF series changes all that. It allows you, the user, to choose the tradeoff. If you enjoy music that is loud but does not have much deep bass, set the VTF series for max output. That way, you get maximum dynamic range with the lowest distortion. If you like music with deep bass, set it for maximum bass extension to reproduce the deep bass accurately. You can even switch between the two modes depending on what you play. That means effectively you get a subwoofer that can play loudly, and can play low, all in one, at one low price!

Have you tried all the different setting/port combo's??

SteveC

thanks for the info, alot of good stuff! I will continue to play around with it and let you know how it goes.

thanks again

Hi John & MCocanti,

I found the analog version much easier to use. Sorry to hear that RS is no longer manufacturing the analog meter. I'm sure you can get used to using the digital version, especially if, as John says, it has a "slow" or averaging setting. We had both types in our listening room at Audio magazine, and I preferred the analog meter scale, which was simpler to read at a glance.

Regards,

Hi Alan,

I must certainly agree with you that anolog instruments are always mush easier to read at a glance. I have the new RS Digital meter, and while I did prefer the analog meter that I borrowed from my friend, the RS meter when put on slow response works very well, I have used it a number of times now when helping others setup their systems with no problems, the readings are stable and usable. For anyone else concerned about this don't be the digital unit works very well indeed just make sure you set the response to slow.

Cheers
John

When using the S&V setup dvd do you calibrate to 75db or 85db? I've heard both.

Thanks,
Heath

Normally you would use 75db at volume reference level of 0db, this is the value that most companies have set as the standard.

Using the S&V disc I calibrated everything to 75. I later read on HTF that the company who developed the S&V disc, Ovation, also made the AVIA disc. I've never used AVIA but apparently the instructions on that disc call for an 85db level. The S&V disc makes no mention of what level to use. I know the Video Essentials disc calls for a 75db level. It probably doesn't make a huge difference but if I'm going to take the time to calibrate I would like to do it as the developers of the software intended.

Heath, I am not familiar witht eh Avia, disc. What I go by is what the deveolpers of the THX and DTS standards call for, and that reference is 75db. It would be interesting to find out why they are calling for the higher value, is there a tech support number that can be caled for information, if there is it would be interesting to find out why the departure from the industry defined standards.

Regards
John.

I thought "true" reference level was 105db. As I understand it the calibration discs have their tones cut down by 20-30 db so we don't deafen ourselves during calibration. I could be totally off base on this as I'm still relatively new and trying to learn more everyday.

Alan,

Do you have an opinion on this?

Thanks,
Heath

Hi Heath,

Good heavens, 105 dB!!!. Don't!

Use 75 dB or 85 dB--whatever is comfortable. It's somewhat arbitrary anyway.You want the test signal to be loud enough (especially with our ears' insensitivity to deep bass as levels diminish), but not so loud that it's uncomfortable. I've been using 85 dB SPL at my listening seat because that's a fairly typical "average" SPL level for much of my listening.

Regards,

Heath,

I meant to add that whichever level you decide on, use that for all future calibrations.

Alan

Alan is right...85db is what the film maker's level they intended you to listen

now this is the way i calibrate my system....

use avia's guide to H/T is a very good and easy to follow
a rat shack spl meter (the one you can't find anymore)perhaps you can find one on ebay

putting the rat shack meter dead center of your listening area... (at ears height) and listen to each speaker individially (make sure your levels on the reciever is at full for all the speakers) take the weakest speaker and put the volume up to when you see 85db and adjust the others speakers down to 85db.... et voila...

except for the sub the adjustment must but a little more than 85db .... u must experiment with the sub, adjustment varies from room size to sub to placement...

i hope this helps...

Interesting to note what you are saying, but then why does the owner's manual of all THX certified receivers specify 75db as the reference point to calibrate to?

Also, reading through most guides on calibration of your HT they say that you should calibrate at the listening position not dead center of the room. I would agree with with this as you tend to be closer to your rear effects in the listening position then dead center. If you calibrated your system with the SPM at dead center of the room then the levels of the rears and surrounds would be set too high.

Johnny and Alan, I tried my HT calibration to 85db but it's too loud and I max out some of the speaker level to +15db...maybe I am doing something wrong. anyway..this is how I've done it....and could you please tell me exactly the steps by steps if I did it really wrong...

There are 3 parameters involve on the receiver settings...
1. Master Volume
2. Individual speaker volume(this volume is set to ref volume when the receiver test tone has been run. this is the volume that was being set if you need to increse/decrease the volume, and not the Master volume).
3. Individual Speaker db level (min -15 max +15 db)

here's the actuall step:
1. set master volume to ref volume (0db)
2. run the receivers test tone
3. adjust the speaker level (not the volume) until SPL measures approximately 85db

after this settings, my systems sounds soooo baddddd....so I have to adjust it back to 75db....is this the right thing to do? S&V says, for 75db, you need to adjust first the volume till SPL measures 70db before calibrating the speaker....and in order to achieve that I have to run the receiver test tone, then increase the volume for each speaker to achieve the 70db on SPL (at this point I can't see the relavance of setting the master volume to ref level, since during test tone as I have said above, the volume I am increasing to achive the 70db measurement on SPL is the individual speaker volume). It looks like the process is run test tone, increase the speaker individual volume to achieve 70db on SPL and then start adjusting the speaker db level to achieve 75db.... is this how it;s done??? If this is the case, then why do we need to set the master volume to ref volume first? and also if this is the case, that means my setup is not really calibrated properly.....:-(....oh btw, it;s okay to use the internal receiver test tone right? or I should use the test cd's (S&V) test tone which is a little lower volume that my internal test tone.....

thanks.....

Hi,

I've never heard of anyone advising calibration at the room's dead center. It makes no sense unless you sit there. Given the vagaries of standing waves, you could calibrate there and then find the subwoofer balance would be totally wonky at your seating location. Not to mention the settings for the surround levels and left and right mains. Technically, if there's a couch, you should calibrate for each seating position along the length of the couch, average the settings. . and ..You see what I mean?

Calibrate only at your seating position and hope the sound is reasonably consistent for other locations. It usually is if the room or setup isn't too eccentric.

Regards,

Hi Alan,

That’s my thoughts exactly, I have never heard of as Johnny says trying to calibrate at dead center it does not make any sense as this is not as you correctly state where you sit.

(Sorry guys for the long post)

With regards to the reference levels, I have just been on the phone to a THX certified installer a gentleman by then of JP was kind enough to let me pick his brains for about 45 minutes. In a nut shell, with regards to calibrations this is the what he said about the 85 vs 75db. 75 db is the calibration guideline for theater, for music the guideline is 85db. The reality is that we listen to a mix of both and unless you have a dedicated theater room there is really no right or wrong. If your manual states 75db (as does my Denon) that is where it was calibrated to at the factory and the levels at which their THX certifications were done. JP also stated that he will change the calibration value for a given room depending on the size and response (live ness) of the room. As for using the meter, Digital is fine, make sure that the meter is set to “C” weighted and slow response. The meter should be placed in your seating position (not dead center) and the meter held vertically not horizontally. If you do not have any way to hold the meter in this position then stand behind your seating position and hold the meter at arms length so that it is in roughly the same position as you would be when seated. You should also sweep the meter left to right and adjust for an average of 75db, or an average of whatever level you are using, again be sure that the meter is held vertically.

I hope this helps

Regards
John.

Sorry Un if I am using this post for something else, but I really wanted to know the proper steps to calibrate the speaker as I have mentioned above....Alan, John anybody, please help, need your response from my post i mentioned above....thanks!!!

Sean,

The correct procedure is to set your volume to any level to begin with, turn on the test tone, rotate the volume to the 0db position, refer to my last post, for details about correct positioning for you and the meter. Adjust individual levels to get to 75 or 85db as you so desire. If you say that 85 does not sound good with your setup then use 75. make sure that you hold the meter correctly and sweep it from side to side and adjust for an average reading.

Hope this helps you.

John

Just want to be clear about turn the volume up...is this the master volume or the individual speaker volume....? The thing is, once I run the test tone, and if I wish to adjust the volume, the volume that I am adjusting is not the master volume but the speaker volume....and as I run the test tone, the volume for that speaker is already started at ref volume 0 db. That;s why I am a littel confuse, specially when setting the SPL first to 70db (or putting the SPL needle to the center (0)) before calibrating to 75db. any thought???/

If that is the case with your unit then you need to set the master volume first to the 0db position, ignore the meter at this point. Then turn on the the test tone and now using your meter from your seating position, adjust the indivdual speakers levels, center, FL, FR, RS, LS, etc.. to get 75db for each speaker channel individually.

Let me know if you need more help
John

I will say this, whether calibrated to 75 or 85 my Axiom setup (M60, VP150, QS8) sounds great. I just re-calibrated everything to 85db and there is no discernable difference in sound quality. Thanks for the additional info John and Alan!

Heath

Thanks John, this is actually how I'm setting up my HT actually...but with this steps, I'm having problem calibrating it to 85db as my speaker db level already reaching the max +15db adjustment and still the SPL only records between 80-83db.

Thought you might want this....

http://www.surroundassociates.com/spkrcal.html

well if you look well at my message i said dead center of you lisning area... and by this i meant where you sit but in the center not to the right or to the left but at the center of the couch right between the the 2 front mains... i have done extensive testing and if the position the spl meter (level of your head and exactly center in lie with the seakers ) is not perfect than the sound will not be well calabrated .... i use a tripod on my leather couch!! wife non approved... but anyways this works for me !!!

Hi Johnny, sorry for the miss understanding, I read it to be that you meant Dead Center of the room when you said dead center of the listening area.

Sean, I saw this earlier today, and thats what prompted me to call THX and in turn get in contact with one of their certified installers, as some of the things in that article did not seem correct to my understanding.

Wow, there seems to be a lot of confusion about this. Whether to calibrate to 75 or 85db depends on which calibration tones you use and what your listening preferences are.

In the case of Avia, the tones are recorded at 85db on the reference scale. That means to get playback at reference level for movies, you should calibrate your speakers to 85db using these tones.

It's entirely possible that the THX optimode and/or Video Essentials test-tones are recorded at 75db on the reference scale, but I don't know that for sure since I don't really use those. But if that's true, then calibrating with VE at 75db would give you exactly the same results as calibrating to 85db with Avia. That's the whole point of "reference-level", it's a reproducible standard. So the best advice if you want to calibrate to reference level is to follow the instruction that accompany the calibration disc you use. The AVIA disc has very good documentation available from the menus for each test.

Now for many people, particularly in smaller home theaters, full reference level will seem very loud with today's action movies, probably too loud. That's fine, you can always turn the master volume down when watching movies. Theoretically, you are sacrificing some dynamic range by not listening at reference level, but in reality few if any movies use that full 105db of dynamic range. Most of todays action-type movies are mixed loud; the sound level is at the upper end of the dynamic range for most of the movie. Dialog-driven movies aren't going to be as loud but they still probably don't use the full dynamic range.

As for the THX guy who said to use 85db for music and 75db for movies, I think you must have spoken to a clueless marketing guy who didn't know what he was talking about. CD audio does not have a reference standard for volume, that's why volume can (and often does) vary from disc to disc. Maybe DVD-A and SACD have a reference standard, but I don't have either so I couldn't say. But for CD audio there's no such thing.

Hi JohnK,

Well with regards to the 75 vs 85 db standards, I have made a call to a friend of mine in LA this morning who is the recording business, and he has confirmed that the reference level for audio is 85db and that The THX technician, (The guy I spoke to was actually a certified tech, not a marketer)was correct that theater is 75db. I agree with you that they should follow the instructions from the disc that this is what the manufacturer of the disk intended, and has done their work on it based on those measurements. But it also does not mean that it is correct or should be taken as the gospel.

JohnK,

While I think that the debate over 75 vs. 85db will continue to ensue fro some time to come, I think that it is important to note that whatever standard you decide upon, and really there are no rules etched in stone about this as for most people trying to listen to your movie or audio at the reference level of 75 or even 85db will be too loud in any case for them. That the main idea is to set a balanced sound stage for your environment, so if you find that in a small room that even calibrating to 65 or 70bd works for you then so be it. Once you achieve the overall balance that the levels from all the speakers are set to the same level at your listening position the rest of it really is not that important as too whether it was done at 75, 85, 65 or even 70db.

John H., note jkohn= Jeff Kohn.

Hi,

Thanks, sorry for the confusion I did not look too carefully at the name and since I see your name often it just registered in my mind as you.

Okay using the S&V test tone, I was able to calibrate my system at 85db and sounds great. I don't know if this is really the behaviour, but after calibrating at 85db using S&V test tone, I run my receiver internal test tone at same volume level (ref), the SPL record only around 78db. Anyway, I had enough with the calibration, almost every weekend this is what I am doing...so time for me to be contented on my current settings, relax and watch movies, listen to my CDs...hmmm I have 3 movies to watch this week, Scorpion King, Lord of the Rings and Panic Room.....ciao

Glad to hear that all is well, and yes it is time to kick back, watch those movies, and enjoy your system. Panic Room and LOTR I have, and both are good movies, LOTR is a great one to watch on your system. I do not have The Scorpion King. Let me know how it is, and if it is worth buying.

well the reason I bought Scorpion King is because it's onsale in Walmart (14.98)...Circuit City (15.something) and BJs warehouse club i believe it's around (17 something). anyway will let you know if it's worth buying....

In reply to:

---

Well with regards to the 75 vs 85 db standards, I have made a call to a friend of mine in LA this morning who is the recording business, and he has confirmed that the reference level for audio is 85db and that The THX technician, (The guy I spoke to was actually a certified tech, not a marketer)was correct that theater is 75db.

---

The THX technicial may be referring to using the test tones in a THX receiver, or the THX Optimode on some discs. Maybe those are encoded for 75db, I don't know. But the point you seem to be missing is that there's not a universal standard for all test tones, they can vary in loudness depending on how they are encoded. In the case of the Avia test tones, reference level = 85. It says so right in the disc's documentation.

As for audio/music, was your friend maybe referring to SACD or DVD-A? Because there is no "reference" for CD-Audio as part of the redbook specification like there is with Dolby Digital.

seanandredj,

The most important thing is that all the speakers are evenly calibrated and that you're comfortable with the volume level. You don't have to play back at reference level, so enjoy your movies. Besides, many systems are unable to play cleanly at full reference level on a loud movie like Lord of the Rings, without bottoming out the subwoofer or driving the amp to clipping.

Jeff,

You are correct that there is no universal standard but there seems to be some implied standards that have set by the industry, and the point was not missed. Now as you state in the next topic that the most important thing is to have even speaker calibrations, which I do believe was the message that I clearly stated to you in my PM (although you neglected to include that part in your cut and paste of the topic) even to the point that I said that it did not matter if you calibrated at 75, 85,65 or even 70db. That once you had these levels set that the value you use to calibrate was not really important.

I quoted the message I was replying to, I'm not sure why you would expect me to quote from a PM, especially since I don't think I had read it yet at that point.

I think we can all agree that the volume level should be set to whatever makes you happy, but at least a couple of posts in this thread were discussing how to calibrate for the standard/reference level, and my point was that in that case you would use 85 for Avia, not 75.

Jeff,

I apologize for my last response. I was perhaps a little hasty then in my reply. What you have said in your next reply to Sean is basically exactly what was posted on page 4 and was what was said to you in the PM. i had made the mistake in naming Johnk and not jkohn when i replied.