Radioshack analog SPL meter?

[L.J.]

Does RS not carry this anymore? When I went to purchase a meter months ago, RS only had the digital meter available. I checked online and only the digital is available. So where's the analog?

I was thinking of purchasing the Rives test CD but it notes that the compensated tones are for the analog meter.

Are there correction values for the digital meter?


What do I need to do to measure my room's response?

[paul_pci]

http://www.radioshack.com/product/index.jsp?productId=2103668&cp=&origkw=sound+level+meter&kw=sound+level+meter&parentPage=search

[L.J.]

http://www.radioshack.com/product/index.jsp?productId=2103668&cp=&origkw=sound+level+meter&kw=sound+level+meter&parentPage=search

What the????

:blush2:


How embarassing!!!! I put in every search word I could think of yesterday. :confused5:

[shokhead]

Could be a store thats being closed down and they are not restocking.

[Woochifer]

Rat Shack had discontinued the analog meter a couple of years ago, and then reintroduced it with some minor restyling. Not all stores carry the SPL meters, so you just need to check around. I'm totally speculating here, but it's entirely plausible that you can apply the same correction values to the digital SPL meter, since the inaccuracies that those values adjust for originate with the microphone. If the two meters use the same mic, then they very well might need the same correction sets.

[L.J.]

I'm such a dork....I put analog spl meter in the search engine instead of analog sound level meter. Now I can get it to pull up. :crazy:

[Sir Terrence the Terrible]

I'm such a dork....I put analog spl meter in the search engine instead of analog sound level meter. Now I can get it to pull up. :crazy:

Perhaps you are feeling the effects of exposure to magic pixie snot!!

[L.J.]

Perhaps you are feeling the effects of exposure to magic pixie snot!!

Man I live off the stuff. It makes my HT experience so much better....:eek6:

[L.J.]

I had to order online. I called all the RS in the area and was told they were completely out. I should have the meter and the Rives test CD by mid week. I'm very curious to see how my room measures.

One thing I noticed about my main system is that everything sounds great in the sweet spot, but if you move out of it(I'm talkin' to the next seat over on the couch) the bass sounds like crap and it just didn't sound good at all. I discovered this when doing a demo for a friend and let him sit in sweet spot. I know the SS is the ideal sitting location, but should the next seat over have that much of a diff in sound?

My first thoughts was to get another sub to fill this in. My room is long and narrow and right now my TV and couch sit against the long walls because this is the only place my wall unit will fit. The sub is in the very far left corner and I'm very limited to where I can place it since the room as huge openings on both sides. I plan on getting bifold double doors for one side where the sub is. I'm sure closing in one side of the room is gonna make a diff in sound, don't know if good or bad, and now I'm worried about the doors rattling. The 2nd sub isn't in option right now and there's probably far cheaper ways to improve this.

So this starts my adventure into new territory. Understanding room interaction and peaks and deeps and all that stuff. I know nothing about room acoustics/treatment, but I guess everyone has to start somewhere. OK now I'm just rambling....

[paul_pci]

When I got mine, only 1 of four area stores had the analog spl.

[L.J.]

Alright, I got the meter and test CD. All I need now is some time.

I was wondering does anyone have any tips or pointers? Any advice on doing this would be appreciated.

Instructions seem to be straight foward and there's a pretty nice article (http://www.audioholics.com/techtips/setup/loudspeakers/subwoofercalibration.php) at AH.

[paul_pci]

Alright, I got the meter and test CD. All I need now is some time.

I was wondering does anyone have any tips or pointers? Any advice on doing this would be appreciated.

Instructions seem to be straight foward and there's a pretty nice article (http://www.audioholics.com/techtips/setup/loudspeakers/subwoofercalibration.php) at AH.

That article is about calibrating a sub, are you just calibrating your sub? or the whole system? The difficulty is of course, watching the readings while staying out of the way of the incoming audio signals, etc.

[L.J.]

My short goal, for both systems, is to measure my room's response and find the best place for my sub with the flattest response.

[paul_pci]

So, the test disc you got has a frequency sweep, I imagine?

[Woochifer]

Alright, I got the meter and test CD. All I need now is some time.

I was wondering does anyone have any tips or pointers? Any advice on doing this would be appreciated.

Instructions seem to be straight foward and there's a pretty nice article (http://www.audioholics.com/techtips/setup/loudspeakers/subwoofercalibration.php) at AH.

That article is a great primer, and if you already got the Rives disc, you should have more than enough to get started. I totally agree with the author about using a camera tripod. At the very least, the tripod gives you more consistent results. Others on this board over the years have generally suggested pointing the SPL meter straight ahead and tilted about 45 degrees. Measurements taken after moving the subwoofer to different locations within the room really point out how much the room acoustics affect the lower frequencies. It also points out how much you REALLY NEED a parametric equalizer! (As if you really NEED to dump more money into your setup, right?) :D

If you're interested in learning more about the Behringer Feedback Destroyer, which is the lowest priced PEQ that I've seen, you should head over to Sonny Parker's website. Excellent pointers over there about room correction and how to use the BFD with a subwoofer. Plus, he has test tones available for download, as well as a spreadsheet that plots the before and after results (and includes the correction values for the Radio Shack SPL meter).

http://www.hometheatershack.com/bfdguide/

Paul's concerns about staying out of the way of the audio signals is relevant for level matching the L/C/R/LS/RS speakers because signals bouncing back toward the SPL meter can distort the readings. But, it applies less when measuring the lower frequencies.

[yogo]

I had to order online. I called all the RS in the area and was told they were completely out. I should have the meter and the Rives test CD by mid week. I'm very curious to see how my room measures.

One thing I noticed about my main system is that everything sounds great in the sweet spot, but if you move out of it(I'm talkin' to the next seat over on the couch) the bass sounds like crap and it just didn't sound good at all. I discovered this when doing a demo for a friend and let him sit in sweet spot. I know the SS is the ideal sitting location, but should the next seat over have that much of a diff in sound?


Look up bass traps on google

one way to tame your bass as well as sub positioning,

[abulgan]

guys,

is there a shop sells Analog SPL meter(RadioShack of course)with open International orders,cause i need one and can't find in my local RadioShack shops,

[abulgan]

hey guys,

i know that speakers must be 75 db and subs 80 db

how 'bout it max. db value?was it 107 db or 110 db?

[shokhead]

Doesnt have to be 75 and i dont know where the 80 for a sub came from. As long as they are set the same you can use 70,90,76,whatever. Mine happen to be 78 and most say the sub should be 4-8db higher.

[abulgan]

maybe u r right,so all channels including SW must be equal?

but also Bass Peak Level must be adjusted so i asked it max value must be 107 db or more?

[L.J.]

here's my test results guys. I have a peak at 31hz and a huge dip at 100hz. I haven't tried to move my sub yet, I only had enough time to do some measurements. I did about 6 measurements and came up with the same results each time.

Question: when running the test tones my system should be set to normal listening calibrations right(speakers set to small, xover @ 80hz)?

[paul_pci]

Wow, that's a pretty flat response. I should be so lucky. I get a real peak about 60hz myself. But yes, I'd imagine you want to run the fequency sweep under normal listening conditions, but why not fool around with settings to see and hear the differences.

[Woochifer]

here's my test results guys. I have a peak at 31hz and a huge dip at 100hz. I haven't tried to move my sub yet, I only had enough time to do some measurements. I did about 6 measurements and came up with the same results each time.

Question: when running the test tones my system should be set to normal listening calibrations right(speakers set to small, xover @ 80hz)?

Wow! I think you should just set it and forget it! That's about as good an unequalized in-room response curve as I've seen. That dip at 100 Hz is a concern, but I have a feeling that it might result from how the bass management typically gets implemented on home theater receivers with the low pass and high pass filters using different order crossover slopes.

If your main speakers can accurately extend below about 50 Hz, you should try resetting the crossover frequency to 60 Hz and see if it sounds better and also if a similar dip occurs around 75 Hz. If the same dip occurs with a lower frequency, then the bass management is the culprit. Provided that the room's not at issue, you might be able to use a parametric equalizer to boost that frequency and smooth out the response curve. Just make sure that any boost you provide is done below 80 Hz so that you don't make the directional frequencies any more audible than they need to be.

[L.J.]

Wooch, I ran 3 tests with a 60hz xover and 3 with a 80hz xover. The dip at 100hz occured at both xovers. One thing I should note is that I ran a test with the xover at 160hz thinking the dip was caused by the xover point and the dip still occured at 100hz. I plan on doing some more tests when I get a chance. Right now my sub is in a corner and my only other choice(unless I go through the hassle of running cable under carpet) is in the center of the room. I'm assuming there's some kinda cancellation or something going on within the room to cause the dip :confused5:

[shokhead]

My B&W's are rated to 47 and play down to 50 pretty good. I set x over at 60 for awhile the got the avia disc and found 80 worked better.

[Woochifer]

Wooch, I ran 3 tests with a 60hz xover and 3 with a 80hz xover. The dip at 100hz occured at both xovers. One thing I should note is that I ran a test with the xover at 160hz thinking the dip was caused by the xover point and the dip still occured at 100hz. I plan on doing some more tests when I get a chance. Right now my sub is in a corner and my only other choice(unless I go through the hassle of running cable under carpet) is in the center of the room. I'm assuming there's some kinda cancellation or something going on within the room to cause the dip :confused5:


One quick question, is the crossover on the sub itself turned all the way up or otherwise bypassed?

That kind of a dip could also be caused if the sub's crossover is set around that point. If your system uses the receiver's bass management, then the sub's crossover should be completely bypassed, or absent a bypass switch or LFE-specific input, turned all the way up.

Otherwise, it's either a room cancellation or simply the actual response from your subwoofer (it's not like all subwoofers have flat response curves). The only way to check is to move the sub, but considering how flat the rest of that response curve is, you've already got it nailed down a lot better than most of us could ever hope to without equalizing or treating the room.

[L.J.]

One quick question, is the crossover on the sub itself turned all the way up or otherwise bypassed?

That kind of a dip could also be caused if the sub's crossover is set around that point. If your system uses the receiver's bass management, then the sub's crossover should be completely bypassed, or absent a bypass switch or LFE-specific input, turned all the way up.

Otherwise, it's either a room cancellation or simply the actual response from your subwoofer (it's not like all subwoofers have flat response curves). The only way to check is to move the sub, but considering how flat the rest of that response curve is, you've already got it nailed down a lot better than most of us could ever hope to without equalizing or treating the room.

Yes, the xover on my sub has a bypass switch.

[L.J.]

Otherwise, it's either a room cancellation or simply the actual response from your subwoofer (it's not like all subwoofers have flat response curves). The only way to check is to move the sub, but considering how flat the rest of that response curve is, you've already got it nailed down a lot better than most of us could ever hope to without equalizing or treating the room.

When measuring room response of lower freq. your measuring the sub's response up until the xover point and everything above the xover is the bass output from your other speakers, right?

[paul_pci]

When measuring room response of lower freq. your measuring the sub's response up until the xover point and everything above the xover is the bass output from your other speakers, right?

I think that is determined by your receiver. For instance, my Yamaha offers the choice of sending lower frequencies to sub only, mains only, or both.

[L.J.]

I think that is determined by your receiver. For instance, my Yamaha offers the choice of sending lower frequencies to sub only, mains only, or both.

Yeah my Denon has the same settings. When I took my measurements my settings were speakers set to small and xover at 80hz. So the bass output at 100hz is being produced by my speakers, not my sub right? I'm asking because moving my sub would not make much of a diff then. I was thrown off by Wooch comment that the dip at 100hz could be the sub's response curve. Or perhaps I'm making this more confusing for myself than what it needs to be.:idea:

[Sir Terrence the Terrible]

Yeah my Denon has the same settings. When I took my measurements my settings were speakers set to small and xover at 80hz. So the bass output at 100hz is being produced by my speakers, not my sub right? I'm asking because moving my sub would not make much of a diff then. I was thrown off by Wooch comment that the dip at 100hz could be the sub's response curve. Or perhaps I'm making this more confusing for myself than what it needs to be.:idea:

If you are seeing a dip at 100hz, with a crossover point of 80hz, this output is coming from your speakers, and partially from the sub also. You may be having some cancellation problems with the combined output of both out of phase with one another. Xovers are not brickwall solutions. Depending on the steepness of the crossover itself, you mains and your sub could be playing a great deal of the same output simultaneously. This can cause frequency cancallations above the crossover point. With bookshelf speakers the problem rarely crops up below the crossover point because the speakers roll of more steeply below their tuning point

Moving the sub would help, but I would advice using the subs phase switch (if its variable and not fixed) to see if that makes a difference.

[Woochifer]

When measuring room response of lower freq. your measuring the sub's response up until the xover point and everything above the xover is the bass output from your other speakers, right?

Sorry, that was a brainfart on my part! I should've remembered that you were measuring with the mains as well. Terrence has already pointed out that the dip is likely caused with your main speakers. In addition to adjusting the phase on the subwoofer, you could try repositioning the main speakers to see if this changes the response curve.

[L.J.]

Thanks for the replies everyone. I'll play around with the phase on the sub and do some more measurements.:thumbsup:

[abulgan]

i've just received the SPL meter and adjusted all channel levels by that,80 db speakers and 85 db for SW,bass is not enough 4 me now,or gott used much more Bass when making levels by Ear,cause SW's r now at mininum according Meter which was near Max.