Audio Equalizers

[riverrat373]

Is anyone here using audio equalizers to improve either the receive audio, transmit audio or both? If so, what brand are you using?

 

[Robb]

Using an equalizer will improve audio; but that can only do so much. To get the full benefit from your radio (dunno what you are using) is to give it the 'Goldfinger' audio mod. This will widen both your receive and transmit audio bandwidth some, but enough to realize a real change.

Additionally, using a quality mic and preamp will also serve to increase audio quality. Not talking about a D-104 here, but a real mid grade studio mic and preamp.

Lot more to it than this, just thought I'd give you a heads up - is all.

 

[sp5it]

I use DSP1124P from Behringer on TX path only.
Mike

 

[dave457]

Flat across the board on eq with a little compression sounds nice

 

[543_Dallas]

I use eq on the rx occasionally to help pull someone out of the mud or if they are too heavy on the bass. I use sdr though. For the price of external audio gear you could use an sdr receiver. Some software like powersdr will have eq settings. My pc has its own eq settings so there's a lot of flexibility.

I use external audio gear for transmit only. The rack consist of an art prochannel with the eq bypassed, a dbx131 (31 band eq) and an aphex dominator 2 peak limiter last inline. The eq is set mostly flat with a lot of attenuation around 100hz and some boost in the 3000 to 4000 Hz range.

 

[Onelasttime]

Like Rob was saying you can not eq what is not there. Does that make sense? So yes EQ's help even on a stock radio but they help more on one that has had it's audio bandwidth widened. This is true on transmit and receive. 99% of EQ's are going to be down with op-amp or audio IC add in a few cap's and transistors and bam!!! Most of them are going to be audio ic's and such that were designed for tape recorders and such to control the AGC and such. Depending on which chip they use you could have multiple stages of gain, two independent channels(easy to do tx on one and rx on the other without added switching), varying number of EQ bands, compression, echo, reverb, delay etc.......2SM2166 is I am remembering my numbers right is a hot little chip in many formats that was used in professional audio gear. If all you want though is EQ you can make any eq work for a 32 band beast to Kenwood 7 band home EQ from the 1980's. It does not have to be radio specific that someone else has already built specifically for radio use. Your level of skill will dictate that.

Ultimately as long as the EQ is quite and preferably has a true bypass for when you do not want to use it you should be fine. In fact, I have seen guys use quality guitar pedal eq's and compression pedals etc.....The first eq I played around with on radio was a trunk mount car audio eq from the 1990's back when I used to be into CB and Car audio.

If you are looking at maybe doing the EQ thing to an FT-101 first I would try a decent electret and see what you see. You might not need to go down the EQ road at all. I do not know what the impedance needs are of an FT 101 I have not seen one or heard one on air for at least 15 years. A lot of older Ham and CB gear had an insanely wide audio bandwidth prior to the 40 channel switch and those early 40 ch tube and crystal hybrids often carried that on for a short time.

 

[Robb]

Is anyone here using audio equalizers to improve either the receive audio, transmit audio or both? If so, what brand are you using?

Using an equalizer will improve audio; but that can only do so much. To get the full benefit from your radio (dunno what you are using) is to give it the 'Goldfinger' audio mod. This will widen both your receive and transmit audio bandwidth some, but enough to realize a real change.

Additionally, using a quality mic and preamp will also serve to increase audio quality. Not talking about a D-104 here, but a real mid grade studio mic and preamp.

Lot more to it than this, just thought I'd give you a heads up - is all.

Gonna assume we are talking a Galaxy 959 here. since you have another post on the forum with that radio.

To mod the 959 with the Goldfinger mod:

Galaxy 900 series radios 919 through 979

Receive

Remove C39
Change C78, C40 and C185 to 2.2uF non-polarized electrolytic
To add more highs change C184 to a .001uF ceramic disc

Transmit

Need more gain for running a stock mic or noise cancelling mic?
Change R-176 from a 270K stock, to a 470K.

Want more Bass?
Change C-154, a .22uF 16V tantalum, to a 3.3uF 16V tantalum.
Change C-171 and C-235 to .47uF 50-100 volt Mylar.

For even more Bass.

Change C-154, a .22uF 16V tantalum, to a 10uF 16V tantalum.
Change C-171 and C-235 to 2.2uF, 50-100 volt Mylar.

the 2.2uF non-polarized and the 10uF tantalum available it Radio Shack.


Goldfinger thanks for the Info.
http://www.wwpdx.com/wwpdx.com/Foru...&t=12330&sid=501b2bf6d5779371c7062de8f714d75d

 

[Sonar]

If your transmitted band width is less than 3khz wide an equal will do little to nothing for the lows.
It seems as if most wanting to use an equal along with a studio mic are doing so to get low. Good luck. 73

 

[Mustang 131]

Is anyone here using audio equalizers to improve either the receive audio, transmit audio or both? If so, what brand are you using?

I found radios with wide xmit needs little EQ. In fact you tend to roll off the real lows and highs. Narrow xmit radios seem to need the most EQ.

 

[riverrat373]

Actually, what I'm interested in improving, without going into the radio, is the receive audio. I want to run the audio into an equalizer before the speaker and wonder if an audio equalizer would work well enough to spend the money on one.

 

[Mustang 131]

Actually, what I'm interested in improving, without going into the radio, is the receive audio. I want to run the audio into an equalizer before the speaker and wonder if an audio equalizer would work well enough to spend the money on one.

Yes. A EQ makes a huge difference on your ears. An expander really makes good AM signals come alive.

 

[dave457]

The kind of speaker you use makes a difference as well

 

[Sonar]

Yes. A EQ makes a huge difference on your ears. An expander really makes good AM signals come alive.

Mustang. I've got a Beringer 802. I bought it abot 2 year's ago in order to give my Madison a try at midfi. Along with a Shure sm 58, and an interface to tie it all together I'll bet you could guess how that experiment went?
I heard an eq could, and normally does an excellent job or improving one's recive.
Can you give me a layman's synopsis of how one tie's in the 802 (or any similar 3 band eq/mixer into a Madison in order to improve the RX? Thanks

 

[Onelasttime]

Not me lows kill your talk power and intelligibility. Lows are specially bad on SSB!!! You might as well cut your power output to 1/4 your current output. Now for local rag chewing the lows are great. you need to be at least 5Khz wide to get anywhere with an EQ! I think the hi's are much more important than the lows. If you can get your -3db down spot up high to 4500Hz you got something. I tend to avoid working too hard on the bottom end if you can get -3dm down on bottom to 80-100 you will sound killer on AM just do not stay their all the time. You set the caps in the radio to allow these extremes then use the EQ to select what you want when you want it!

Too be clear I am not saying you need to sound like a D104 just that you can either waste your rf power on audio that is just hurting you or you can use it for all it's worth. Knowing what you want and when you want it is the first part of the battle.

Even mobile with a 1 transistor amp and latter on a 2x MRF455 amp people that I was a base station. Why? Because I could walk over people at will and was bending needles. How? Making the most of what you have. I think Gold FInger goes a bit over board and stock is a bit under whelming. I find myself often going for a sound that between the two extremes!

I find myself paralleling some lytics with film caps often with a smaller value on the lytic or the stock value. With each cap in the chain getting a bit more aggressive and usually ending up at about the same point as gold finger. Since I talk a lot of side band I can not just go crazy with capacitance of I will kill SSB audio.

An example I did a Goldfinger mod once where the stock audio cap first inthe chain is a .22uf lytic and Goldfinger called for a 2uf cap. If I recall I went with a .43uf Nichicon audio grade lytic paralleled with a .10uf film cap. The next cap in line also .22uf but Goldfinger called for 2uf cap. I think I ended up with 57uf Selna paralleled with a .10uf film cap. The last one was a ceramic and I think it was a 1uf and he wanted you to go to 2uf well I found that a 1uf wima did just fine I did not need 2uf. I lowered the bottom end and the top end so even with just a decent stock mic it sounds better but when I use an EQ it really comes alive.

I have a voice like Darth Vader so I need more lows like I need an extra hole in my head! I needed more hi's and wanted smoother audio. I ended up getting a little more bottom end and lot more top end and really smoothing things out. When I use an EQ or an Electret Mic it really comes alive

 

[Shadetree Mechanic]

Some people use a good set of computer speakers.