# Eq w/ spectrum analyzer



## wilkes5

Looking for a good** (seems like os is the only option?) single din equalizer with spectrum analyer like some pictured below.

seems like came across an os kenwood which was really nice and can't seem to find it combing google images with key words like "car equalizer" and "spectrum analyzer"...


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## Weigel21

You talking about the Kenwood KGC-9044 you have a photo of in your post?


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## teldzc1

Alpine Era-g320 was a dream piece for me


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## ATOMICTECH62

The pioneer is a DEQ-9200.
The problem with these old school units is,They can only take 500mv input.This is for a flat response.Once any of the bands is boosted its gets worse.At a 10db boost the unit will clip at .05 volts input.The old school decks with .5 volts out is a must with these EQ's
Any newer deck with 2-4 volt preouts will overload the EQ input circuit with ease.


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## wilkes5

Weigel21 said:


> You talking about the Kenwood KGC-9044 you have a photo of in your post?


well, units like such in general? perhaps you have some info alone on the KGC-9044??



teldzc1 said:


> Alpine Era-g320 was a dream piece for me


awesome possum, maybe look into finding a used one? does the g320 come with like a control module (like a small amp)? what ATOMICTECH62 said has me a little worried... but if the g320 has the module, doubt it sacrifices SQ with the 500mv things, but could be wrong?



ATOMICTECH62 said:


> The pioneer is a DEQ-9200.
> The problem with these old school units is,They can only take 500mv input.This is for a flat response.Once any of the bands is boosted its gets worse.At a 10db boost the unit will clip at .05 volts input.The old school decks with .5 volts out is a must with these EQ's
> Any newer deck with 2-4 volt preouts will overload the EQ input circuit with ease.


do you know anyway around it? do you know any units like such which can receive more the 500mv? do have a sony es c910 with a XDP-776EQ and wondering if it has the 500mv problem (was wanting to upgrade to something a little more pretty). how about 1/2 din eq's pictured below, do have the same problem as the spectrum analysers (500mv input)?


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## wilkes5

wish someone would have guided me through a good system layout trying with the good equipment like 10 years ago (lots of "know how"). got really lucky with a stock new GS redline 10000 with matching subs in a huge "hand me down" box a classmate didn't want any more (think he was wanting something louder)? yea, the sub amp, a matching GS component amp, and my HU got stolen one night... aw the usefulness of bolthing you stuff down and having a 2 way...priceless? year 2001

2002, 2003 stupid me, ended up wrecking my car and the magical slot ported sub box went to the junk yard. didn't pay to get the car out and lost the box with subs (stupid, because the box and subs were really probably tuned just right on luck lucky when could have just saved up and bought a new amp, but was like 16, 17 years old and didn't even know about ebay...like 4 years ago, sonic electronics or woofer etc had the GS 10000 NEW for like $270, the amp was made in Korea and although did read some criticize it's insane output, it sounded really good to me and it _senses_ like a well made amp from _my_ street smarts). maybe someone got some use out of the box?


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## Weigel21

Just that there was a couple on eBay when I first posted, but just one as of now. It's got a fairly hefty $250 asking price with $25 shipping. honestly, I'd invest such into a DSP which can offer more EQ bands as well as T/A and so much more. 

May I inquire as to why you are so interested in getting one?


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## wilkes5

Weigel21 said:


> Just that there was a couple on eBay.......May I inquire as to why you are so interested in getting one?


because owned like an old kenwood minidics double din with built in spectrum analyser and the controls make it handy to adjust from song to song AND for low volume listening in which you use the "smiley" EQ setting....(ask me if your aren't following). to have some eq controls up front seems like a wise idea. however, if you could go through your intier library and adjust each song independently, you could have a really nice listening exeprience possibly. but most songs for me (download from independent artists) vary BIG TIME and can hurt my ears. which is why have found out to use "replaygain" or something like it to adjust my library to the same level. but even then, some songs are too harsh in some frequencies and controls up front seems like a wise idea. 

see, it's stuff which was learned the hard way by me. still wish someone like 10 years ago would have laid it out for me like such. lots of "know how"


DSP seems like the way to me too (some would argue). along with the kenwood, had an Alto Mobile UCS pro, owned it like 4-5 years ago before Arc audio ps8, zapco dspz8, rockford 360, bit ten, bit 1, mosconi, MS8, before all such mothers came out. (to me the alto still holds it's own with the new ones) was thinking, "why the yuck doesn't somebody make more like such?" 5 parametric eq bands or so per channel really is awesome in midbass . had it sounding like a drummer boy tatting in my rear doors. midbass IS really a whole new world just like sub bass.

but don't other ppl say you really don't need such processing? and me agrees to a certain point. like the bass region for example...if you have an amp with a low pass and sub sonic and bass boost region, it's like 3 variables which all you need to curve out cabin gain maybe? correct me if wrong...usually, 40 hertz on up is what plays loud yes (hard to get 25-35 to play loud?), so, just use to lowpass to cut it out...and if it doesn't flatten the response, hit a region with the bass boost? 

but still to me....the experience which was had using the 5 parametric bands of eq with adjustable Q through 150-350 hertz or so was really thrilling.. 

looking to set up amps with audiocontrol 4xs and eqt's maybe off a good HU with some kind of eq up front while most of my music will be played through an mp3 player with "rockbox" software installed which gives me like 10 or so bands of parametric eq with extremely adjustible q also (also replaygain off the mp3 player). 

doing such seems like puts the most (usa/Japan/korea) equipment in my car


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## Theslaking

wilkes5 said:


> do you know anyway around it? do you know any units like such which can receive more the 500mv? do have a sony es c910 with a XDP-776EQ and wondering if it has the 500mv problem (was wanting to upgrade to something a little more pretty). how about 1/2 din eq's pictured below, do have the same problem as the spectrum analysers (500mv input)?


You can get inline RCA attenuators. They reduce the voltage. You can get ones that have a gain control or ones that reduce the signal to a specific voltage. Harrison Labs makes attenuators that have never done me wrong. You won't spend more than $30 bucks on one so I wouldn't let low input voltage deter you from getting an old spectrum analyzer. It is a factor you definitely have to be aware of.


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## wilkes5

thanks for the heads up. a way to measure the voltage with meter (from the rca ends?)? are you fairly confident most eqs are set up to receive such low voltage? a way to tell what voltage the eq is comfortable at? (maybe the way is sounds "clipping", can you explain) or perhaps me is being too lazy and you need to yell me to do a search, but figured you could layman’s terms me, quick and to the point.


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## wilkes5

Alpine 3347 Equalizer seems good


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## SUX 2BU

Where did you find a pic of that 3347? I have a 3348. Identical but it does not seem to have a spectrum analyzer function, which really disappoints me. I don't know what the difference between the 3347 and 3348 is but that might be it. I'd like to talk to whoever has a 3347 to see how it operates as I do not have a manual for mine.


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## wilkes5

believe it was a goggle search. maybe even you tube? sorry

but yea, it senses to me to be a pretty good unit. wonder what year it came out?


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## Weigel21

You could play various 0dB test tones and measure the RCA's on the HU with a true RMS DMM to see the voltage output. This would give you the maximum voltage output the preamps would produce. given music is dynamic and frequencies throughout it rarely ever recorded at 0dB, you could play attenuated test toes of say -5dB to be a more realistic output level from the HU when playing music. 

What HU are you planing to use? While many may argue today's HU's aren't as good as HU's of years past, many today offer 5-9 Band parametric EQ's, some of which with the ability to change the Q factor. Granted, most don't offer separate bands per channel, like DSP's can offer. Even these external EQ's you are looking at are limited to applying the EQ adjustment across all channels. 

Seems the Mini DSP has a fairly strong following for an inexpensive DSP. There's also the PPI DSP. Either of those would do more than what these EQ's you're looking into offer.


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## teldzc1

I'd love to have one just for the display.


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## wilkes5

Weigel21 said:


> ......... I'd invest such into a DSP which can offer more EQ bands as well as T/A and so much more......



man, totally missed what you said ^^ but got everything else in the post.

agreed about mini dsp (somewhat, not sure which holds the best worker rights/ethics in the build) maybe the same internals as the name brand guys but cheaper (have no idea were the build house is...probably china).

really cool about measuring the HU. Might stick with my Sony c910, however, Alpine CDA-9815 senses to me to be the better...(agian, perhaps soul wise and not actual perceived tonal quality)


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## wilkes5

is it necissary to know the input rms of the eq (a way to measure)?


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## SUX 2BU

Can anybody tell me what typically drives the spectrum analyzer to actually do it's movement thing? I tried out my 3348 again recently and cannot get the spectrum display (there is 11 to choose from) to actually display. Everything else works fine, and the display works fine when selecting EQ bands, etc. But when it comes to seeing the 'dancing bars', it shows nothing. In talking with another 3348 owner (they are hard to come by), he has a couple with the same issue and he's said another person told him it was a lot of dried-up capacitors that caused this which required replacement. Any info on how these work would be appreciated.



As for the concern about the 0.5V input and whether or not newer 4V decks will clip the older units, I have found this not to be the case. I'm currently using a 4V Premier (Pioneer) CD player with an old skool Alpine 3656 crossover and have my Alpine 3348 plugged in as well and have zero clipping issues that I can hear. In fact I've run this deck for over 10 years on the same 25 year old amp/eq/xover equipment and have had no issues with input clipping.


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## wilkes5

(hypothetical, maybe take with a grain of salt, or it might actually work)

replace all the caps yourself with same size made in japan/korea? just take the board out, unsolder the solder poinst for each cap, and install/solder the new ones in. (if the caps are the problem). 

however, finding the caps responsible for the display only would save you from soldering and buying probably 10 more caps?

maybe be careful, have replaced componets in my computer (the screen power inverter) when the screen wouldn't function. perhaps static tripped some diode on the small pcb board mounted on the mother board when intalling the new inverter. because, after installed the screen still wouldn't work. 

maybe it was my guardian angle telling me to touch the little pc (which the wires lead to the screen) on the mother board to restatic the diodes to set by to normal. whatever it was, IT WORKED. computer screen up and running. (had dropped my computer before and had to replace the cracked screen, ounce the screen was replaced, it didn't work, then read about replacing the power inverter, did so, then it worked. so, it was teh second time with the inverter (pretty cheap part).

which has me thinking, maybe the 3348 has a power inverter just like the computer screen. or aleast a section on the board for the screen which needs the caps replaced.

good luck

maybe send in into a repair shop (a respectable repair shop).


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## ATOMICTECH62

wilkes5 said:


> is it necissary to know the input rms of the eq (a way to measure)?


You would need a signal generator and a scope to really find out.

The older Kenwood KGC-6042/4042 and Pioneer EQ-6500 are the ones I know of for sure.
The owners manual of the DEQ-9200 states .5 volts input.

These units don't have an internal switching PS so they can only give the opamps a single sided voltage.Normally its regulated at something like 8 or 9 volts by using a transistor or voltage regulator like the LM7809.

https://www.fairchildsemi.com/datasheets/LM/LM7805.pdf

I have seen some older higher end units with a switching PS that can accept and put out much higher voltages.These units have an internal +/- 15volts.The Audio Control Four.1 is one example.
I remember an older Pioneer EQ with SA I repaired about 15 years ago that actually had the switching PS in an external box that attached to the main unit.Similar to some of the Alpine and Eclipse high voltage HU's.
Without a spec sheet the only way to really find would be to open it and check the voltage on the opamps Vcc pins.

Its pretty safe to assume any opamp with a split supply of +/-15 volts can take 4-5 volts and produce up to 9 volts RMS on the output.
The 4580 is a very common opamp used in a lot of these units.If you look at the graph on the bottom of page 4 it will even show THD vs output voltage for +/- 15volts into a 2k ohm load.

This Data sheet also shows that pins 4 and 8 are voltage input.If measured across them you should get around 25 to 33 volts DC.

http://akizukidenshi.com/download/NJM4580.pdf


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## MobilePioneer

ATOMICTECH62 said:


> The pioneer is a DEQ-9200.
> The problem with these old school units is,They can only take 500mv input.This is for a flat response.Once any of the bands is boosted its gets worse.At a 10db boost the unit will clip at .05 volts input.The old school decks with .5 volts out is a must with these EQ's
> Any newer deck with 2-4 volt preouts will overload the EQ input circuit with ease.





Theslaking said:


> You can get inline RCA attenuators. They reduce the voltage. You can get ones that have a gain control or ones that reduce the signal to a specific voltage. Harrison Labs makes attenuators that have never done me wrong. You won't spend more than $30 bucks on one so I wouldn't let low input voltage deter you from getting an old spectrum analyzer. It is a factor you definitely have to be aware of.


good info. Tagging this to learn more. I like the look but they don’t seem to have a function anymore


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## chuyler1

wilkes5 said:


> does the g320 come with like a control module (like a small amp)? what ATOMICTECH62 said has me a little worried... but if the g320 has the module, doubt it sacrifices SQ with the 500mv things, but could be wrong?
> 
> do you know anyway around it? do you know any units like such which can receive more the 500mv?


Kind of an old post that was just bumped but the Alpine ERA-G320 will accept a 2v input and has a light that will turn on if the input is being clipped. You can get to roughly 27/35 volume setting on newer Alpine 2v decks before bass starts clipping the G320 input. You can get up to 32/35 on less bass intensive music. The output is 2v as well and will start clipping at around 32/35 volume. The unit is still pretty decent if you are looking for old school vibes, but it is not worth the prices people ask for them on eBay.


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