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Zeromus-X
12-05-2002, 08:32 PM
Well now, here's some interesting data for those who care about it.

Preface: This test should not be taken as the be-all end-all of wireless tests for these units. I did this in a matter of five minutes using a bassline that I played by hand. When I have more time, I'll use a reference tone (such as a bass drop) which would be identical through each wireless system, and we'd see a definite cutoff point. However, since this is for a bass rig, I figured the easiest thing to do would be to run the bass through it.

Test equipment:

Ibanez EDA-900 - Piezos off, Magnetic on full, tone on full.
to Spectraflex Fatso-Flex 10' braided nylon cable
to *
to SansAmp RBI
to TC Electronic Triple-C compressor (in effects loop)
to CBI 14 gauge speaker cable
to Sound Blaster Audigy sound card, Line In
to Cool Edit Pro 2


where * is the method being tested -- nothing at all, the Samson, or the Sennheiser.

The two models being tested are a Samson VHF-TD wireless unit ($149 at American Musical) and a Sennheiser Digital 1000 wireless unit ($299 at American Musical, cheaper elsewhere). I put a new Energizer e^2 9v battery in the bass for testing this, and each wireless transmitter also has a new battery (the same as the bass, Energizer e^2). The bass itself is tuned to a dropped C# tuning (all strings down 1/2 step; bottom string down a full step further).

Step 1: Frequency analysis of low E string.

Cable:
http://www.starconrpg.com/wireless/Cord_Low_CSharp.gif

Samson:
http://www.starconrpg.com/wireless/Samson_Low_CSharp.gif

Sennheiser:
http://www.starconrpg.com/wireless/Senn_Low_CSharp.gif

The most drastic difference in these pictures isn't the low end, but what appears to be the low-mids -- the cable and the Sennheiser graphs show a gradual decrease between 200 Hz and 500 Hz, while the Samson drops suddenly around the same area. All testing shows a spike around 15000 Hz which I will assume is being induced by either a cable with interference or the computer itself, as it's present in all samples.

Cable: 33.64 Hz @ -30.6 dB
Samson: 33.64 Hz @ -29.75 dB
Sennheiser: 33.64 Hz @ -28.26 dB

When viewing the decibel levels for each, it's interesting to note that the cable scores the lowest. This could be due to the gain being set too high on the wireless receivers, however.

Combination of C# note for each method
http://www.starconrpg.com/wireless/Combination.gif
Green = Cable, Red = Samson, Purple = Sennheiser

This chart makes it a little more obvious which unit is boosting which frequencies. Interestingly enough, the Sennheiser appears to beat out even the cable itself for most of the test above 250 Hz! I can't explain this one, as I'm not using a shit cable. Perhaps a fluke. I don't know.

Step 2: Frequency analysis of a series of notes.

The next three graphs are frequency spectrum analysis shots of a simple note progression: C# D E E D C#. Simple up and down. Each is done twice per unit tested (i.e. the cable one goes C# D E E D C# C# D E E D C#), with the first time being hit moderately hard and the second being played gently.

Cable:
http://www.starconrpg.com/wireless/Cord_Full.gif

Samson:
http://www.starconrpg.com/wireless/Samson_Full.gif

Sennheiser:
http://www.starconrpg.com/wireless/Senn_Full.gif

Combination:
http://www.starconrpg.com/wireless/Complete_Full.gif
Green = Cable, Red = Samson, Blue = Sennheiser

All the methods are about even on the low end, with the Sennheiser again winning out for the low-mid range.

In conclusion it seems that both the Samson VHF-TD and the Sennheiser unit accurately reproduce the low notes of a bass. The sound quality is what really counts. I have no way of measuring the amount of static one gets when walking around or anything. I have not had the Digital 1000 long enough to fairly judge this yet, either. I'll be able to post about that when we do our next show, at which point you'll get another full review if you'd like.

If you can see one thing from these charts though... the Digital 1000 and a standard cable sure look about the same to me!!

Cable (green) vs. Samson VHF-TD (blue):
http://www.starconrpg.com/wireless/Cable_vs_Samson.gif

Cable (green) vs. Sennheiser Digital 1000 (blue):
http://www.starconrpg.com/wireless/Cable_vs_Senn.gif

If you wish to hear the audio sample I used to make these charts, click here (http://www.starconrpg.com/wireless/Cable_Samson_Senn.mp3).

Thanks, and I hope this helps someone!

jesus, etc.
12-05-2002, 08:36 PM
i have no use for wireless. i dont move on stage. i get too freaked out and just stand there. this one time i started tapping my foot....but then i caught myself and stopped.


cool test though. i'm glad to know there are some smart people on the forum

Zeromus-X
12-05-2002, 08:40 PM
Well, this whole thing came out of the other Digital 1000 thread I posted. So if anyone is wondering "wtf", go see that thread first I guess. ;)

Maybe it'll help someone, that's all.

BassDemon
12-05-2002, 08:40 PM
That is awesome dude


I might buy me one of those

Pj_Punka
12-05-2002, 09:01 PM
Ive been considering getting a wireless for awhile now, after your little study there i think ive been won over :D

Pj_Punka
12-05-2002, 09:08 PM
Originally posted by Zeromus-X


If you wish to hear the audio sample I used to make these charts, click here (http://www.starconrpg.com/wireless/Cable_Samson_Senn.mp3).

Thanks, and I hope this helps someone!

Hey you should make a song out of that test track, its a catchy riff ;)

bholder
12-05-2002, 09:16 PM
Nice work, Z-X! I do notice the Sennheiser seems to have a bump in the 2K-9K range, which is curious, but it tracks much more accurately in the low-mid 250 to 2K range which is probably more important to bass tone. I haven't played much more with mine yet, other than the little bit last night, and I'm nowhere near this scientific, but I'm impressed. Thanks for the data.

(And for Jesus, etc., I didn't get this so much so I can move around a lot, though that'd be all right, the main reason is that so I stop tripping and stepping on my cord and tearing the cord ends and output jacks up.)

Zeromus-X
12-06-2002, 03:19 PM
If anyone cares (feel free to post if you do), I'm going to be running a test tone through the thing tonight. Basically, it'll be a tone that increases linearly from 10 Hz to 10000 Hz. Frequency analysis on that should tell us the exact dropoff point of each of the wireless systems (or it'll tell us the dropout spot of some random piece of my equipment... hah) as compared to a cable. The signal will be generated from a computer and played back exactly the same for each method, whereas the previous test was all done by hand so there's a good chance for some errors.

I also plan on finding out, using this method, wtf that 15k spike is. Maybe it's something in my bass. I don't know.

L. Ron Hoover
12-06-2002, 03:30 PM
That's really cool. I would have suspected the Sennheiser to be closest to the cable. The HF attenuation in the cable with respect to the Sennheiser is likely due to inductance in the cable.

Mudbass
12-06-2002, 03:35 PM
This is good stuff Zero. I'm curious to see what it looks like with a test tone as the source material.

MrJoshua
12-06-2002, 03:39 PM
How much for one of those Sennheiser units? I could use a good wireless - I move around a LOT on stage. :)

Zeromus-X
12-06-2002, 03:44 PM
Originally posted by MrJoshua
How much for one of those Sennheiser units? I could use a good wireless - I move around a LOT on stage. :)

American Musical has 'em for $299. I gave allan a link on another thread to a place selling them for $239, and American Musical will match the price. If you spend another $11 there, you can use their Easy Payment Plan, which is split into three equal payments. Also, they don't charge shipping. I got a Roadie Wrench with mine, for the hell of it.

MrJoshua
12-06-2002, 03:59 PM
Originally posted by Zeromus-X


American Musical has 'em for $299. I gave allan a link on another thread to a place selling them for $239, and American Musical will match the price. If you spend another $11 there, you can use their Easy Payment Plan, which is split into three equal payments. Also, they don't charge shipping. I got a Roadie Wrench with mine, for the hell of it.


Darn it, I'm drooling on my keyboard!

Jugghaid
12-06-2002, 04:26 PM
I'm sold.

**Honey, I know what you can get me for Christmas!!!!!**


Hey, do you have any idea what extra trasmitters would cost? I know it's a 4 channel reciever and I would want 3 transmitters for my 3 main axes. That way I don't have to get more recievers as well.