Here is a pic of an Aiwa I own. What are these things measuring, decibels? power? What do the numbers mean?

By the way how come the +3 yellow light comes on even though the needles are still in the negative (black) zone?

because the meter's are mechanical and cannot respond as fast as a electrical Led or light can and in this case the +3 db's Peak indicator is lit well before the meter's can respond and probally the signal has fallen back below and the needles dont reflect that peak ....

the VU Meters are Good For Showing a AVERAGE Musical high

Me when recording using quality tape Chrome or better ... metal ... I dont record any past the +3 using meters

and I dont record past +6 using digital or led's

Hope that helps ... James

VU meters measure the relative average voltage level of a signal compared to electrical noise. The values are determined by a specific voltage across a specific load value to represent what 0dB is. Anything above and below that is a logrithmic representation of its value from the 0dB reference point. Human hearing is on a non-linear scale when it comes to the "appearance" of loudness > logrithmic to be exact.

The +3 could be as mentioned above the meters are to slow to respond.....especially on the aiwa's, and also it could be that the pot is in need of calibration.

Without a scope, it would be hard to see properly.....so I'd say leave it alone. Those aiwas suck to work on......very hard....everything is hardwired...no connectors if any.

Thanks......So what is the significance between negative and positive? Is the red zone "bad" in some way? Maybe bad for recording, but OK for listening, right?

thats about correct --
if the meters are accurate - the red light means you may be overloading the tape at the peaks

the more negative it is, the more "hiss" you'll hear when you play back the recording, more positive will "overload" the signal and distort the sound quality. While MINOR +'s can be ok, you must ensure the quality of the tape medium can support the overage. Most normal tapes can handle a few +3 peaks with little impact. Cr02 and Metal tapes can typically support +6dB without distortion, but is NOT recommended.

Ideally you would like to have the target set for 0dB for playback and recording. It's better to be a "hair" over than under 0dB.

If I'm just listening to my iPod, I notice that the meters go up with the volume on my iPod. Should I set the iPod volume so that the meters stay under the red, or does that matter? I see what you're saying about getting distortion if I was recording, but if I'm just listening it doesn't matter what the meters say, right?

0 is optimal, shoot for it

yes -- the red zone is much more important in recording --for listening -- almost anything goes---

but please remember that boombox meters , at best, are not real dependable if you are trying to make quality recordings

and especially so for any box one buys from ME --
like that TPR 950

Rule of thumb that I remember was to let the needles just "kiss" into the red, and no higher--you'll get great recordings.

A question I needed answers too as well, and just never thought enough about it to ask.

Great thread everyone!!!

So I'm guessing there aren't any boomboxes with both meters and LED bars, since they serve the same purpose?

the conion model # c100f has both

quote:

Originally posted by redbenjoe:
the conion model # c100f has both

Oh yeah you're right

Really though, the Lasonic TRC-931 has the "pimpest" LED's of all......Too bad the rest of the box is kind of gaudy

They both show diferent things. The LEDs are for the Peak Level and the VU Meters are the average level. My AKAI GX75 has a LCD Peak Level Meter at -4 dB is a second Mark "0 VU", those are diferent values for diferent things. The most analog Meters show the VU and LED/LCD Meters show the Peak Level.

It's easier to adjust the recording Level with Peak Level Values as to use VU Level because they both get calculated diferent.

The VU Level most of the Time is under the red area, at the most cases you have to listen to the whole song if you want to set the level for it, the loudest point for peak level is easier to find.

You can download a shareware of Wavelab Lite, it shows VU and Peak level at the same time if you record something, then you will see, that VU the most time is under the values of Peak Level, so your Aiwa acts correctly and the needles are not too slow to show the 3 dB, there aren't 3 VU, only 3 dB Peak.

Cheers, Tobi

SO basically, if you have analog meters, do your recording at 0 db, but if you have LED meters instead, record at around 3-4 db. Right?

Yes, but trial and error comes in to it, see what works best for you, your box(es) and the tape type you're using. If you're using metal tape you can push things a bit further but there's no value in going beyond a certain point. Plus, as some folks have already touched on, the accuracy of meters/led displays can vary wildly, 0 db on one unit may be +3 on another and so on... Have fun!

In most cases the manual instructions show how to record with the VU Meters on your unit, maybe somebody here has an instruction book for your unit.

It's not only the tape type, it's a thing of diferent brands too. There are Chrome tapes who have low dynamics and some with wide. The Chrome type was a german developement that was patented by BASF in the early 70s. Only BASF, AGFA and a few other German Brands produced the Original Chrome Tape. ORWO used that too, but the east german tapes were not as good as the german tapes.

Then the japanese came with their chrome spare tapes, Sony with UX, TDK with SA and maxell with the UDXLII and later XL II and UD, in USA there was Memorex and Scotch/3M, all those tape types where not original chrome tape but usable at the same position as the german chrome tape by BASF and they were much better then the BASF tapes. They got a higher Frequency response and a higher dynamic range.

With a BASF Chrome Super II from the 80s you can do good recordings, but when I use my AKAI GX75 a Maxell XLII or a TDK SA I can level til +4 dB without distortion, BASF only gets it til under 0 dB, that means more hiss, worse then that are the BASF LH Tapes, I can't calibrate them on my GX75, it's not possible to get good recordings with them, TDK D or Sony HF and Maxell UR are much better. So when there is a description how high to level tapes it is related to the tape the tape bias and the dynamic is adjustet to. You will hear a diference if you record to a Sony UX or a Maxell XL II or some other brand, the quality of the tapes are almost the same, but they got diferent saturations and dynamic ranges, they are about the same bias but not exactly, so you get more or less highs then the original, and the recording level will be lower or higher then adjustet when it was recorded, there is only one brand of tape for every position that makes perfect recordings on your radio, you can adjust it to every brand, but it's hard work on a recorder without monitoring, so you should find out, on which brand your recorder is adjusted, or give it to your radio shop who can calibrate it to your favourite tape brand on every tape position. On radio recorders it's not such a big thing, it's no HiFi Stereo where you can hear every little diference but on recordings with dolby or other noise reductions it's very important to use the right tape, if not the noise reduction doesn't work correctly and the sound is like the tape is worn out when the noise reduction is swichted on, so better Tapedecks got a bias calibration and a saturation level or an automatic tape calibration computer to do perfect recordings on every brand, on such a tapedeck it is hard to hear a diference between the original and the tape recording, you can listen there to the tape while you record it and compare the original and the recording, with dolby C or S the hiss is so minimal that sometimes you could think you listen to a CD.

When you only play tapes you shouldn't mind about that, because if the tape head is adjusted right and the tape selector switch (if there is one, if not the tape type switches automatically when the cassette is inserted or the recorder can only play and record type I tapes correctly, Type II and Type IV then have more highs) is in the right position you should every tape play perfect. Then your VUs are a nice visual feature without a big meaning, it's only needed when you record something.

Cheers, Tobi

quote:

Originally posted by Tobi:
They both show diferent things. The LEDs are for the Peak Level and the VU Meters are the average level. My AKAI GX75 has a LCD Peak Level Meter at -4 dB is a second Mark "0 VU", those are diferent values for diferent things. The most analog Meters show the VU and LED/LCD Meters show the Peak Level.

It's easier to adjust the recording Level with Peak Level Values as to use VU Level because they both get calculated diferent.

The VU Level most of the Time is under the red area, at the most cases you have to listen to the whole song if you want to set the level for it, the loudest point for peak level is easier to find.

You can download a shareware of Wavelab Lite, it shows VU and Peak level at the same time if you record something, then you will see, that VU the most time is under the values of Peak Level, so your Aiwa acts correctly and the needles are not too slow to show the 3 dB, there aren't 3 VU, only 3 dB Peak.

Cheers, Tobi

oh i agree on listening on the entire song to locate the highest peak...this is true when i dump most of my vinyl or tape digitally its a pain adjusting it...tho what i noticed is that that most vinyl recordings is in the -3 or 0 zone i would have to leave it so no distortion is picked up in the red zone....but i like to stick to the zero zone in all recordings or playback to be safe of not enough or too little if the recording allows in most cases

Wow, a veritable fountain of knowledge here! Thanks Tobi!

Hey Blaster, you should use a recording software with a normalizing function, then you can record your vinyls and tapes on values under the maximum, after recording it to your PC you can try out the Normalizer, it analyzes your recordings and searches for the loudest parts, then it takes the whole file to the max. possible recording level, so it's as loud as possible and you have no distortion but you nevertheless should not record it too low, before the signal gets digital it goes to an analog pre-amp on the soundcard, that could add new hiss to your recordings, but when you use a value between 0 and -10 dB you can get good results with a normalizer.

Thanks for your nice reply, Reli, I hope it helped you. How does this Bosch System sound? Is it like the Kaboom or worse or better and has it a better Tuner and CD Part then the JVC?

Cheers, Tobi

quote:

Thanks for your nice reply, Reli, I hope it helped you. How does this Bosch System sound? Is it like the Kaboom or worse or better and has it a better Tuner and CD Part then the JVC?

I have never tried the JVC. The Bosch isn't very stunning in the sound department. I bought it a long time ago just because of the way it looks. And now everyone and their mother has one, so it's not special anymore. Oh well, at least it's durable & rugged, LOL.

In some respects the VU scale is very
technical thing.
A bit much to throw at the average consumer.

For most recordings it should be kept
between 10 and 5 db and dont let the
peak lights come on too much.

Bosch, Millwakee, Makita also have versions of them power boxes.
Saw them side by side in a store window the other day.

In some cases the VUs are frequency response corrected because the highs are more sensitive then the lower frequencies, for adjusting the recording level not too low the highs are "circumcised" but only on the Display, not on the tape...

Cheers, Tobi