Stereo equalizer connection to integrated amplifie


I know that the use of equalizers is an affront to the sensibilities of many audiophiles but a combination of hearing problems and an unfortunate listening room layout force me to, at least, consider trying one. My primary goal is to attenuate those frequencies that are painful to my hearing due to a condition called hyperacusis.

I've never in 50+ years used an equalizer and have a couple of questions that will expose my near total ignorance of the issue. To begin with, I use a Rogue Audio Sphinx integrated hybrid amp with a tube based DAC between it and the CD player. Part of my concern is protection of the amplifier because I don't know what voltage levels are delivered from the equalizer to the tube input section of the amplifier.

In reviewing the various equalizers available, many seem to be designed for other purposes than home stereo use such as studio mixing; the rear panels depict connections with which I'm not familiar, some with what looks like microphone plugs. Most all of the others with with RCA plugs have record in and out connections with " out to amp" RCAs. Does this mean that the equalizer is taking the place of the preamp and that the pre section of the integrated amp should be bypassed?

Also, some of those advertised are designated as being parametric. I've tried to find info on what, exactly, this means to the process and is it a better way to go? Many of these, btw, seem to be of the type with the multiple connections on the rear panel that I described above.

I'm sorry to be so uninformed on the subject that it may be difficult to provide answers that I'll understand but any input would be very much appreciated.
128x128broadstone
Hey Broadstone,
No need to multi-explain so much why you need EQ, It's much simplier than you think. EQ is to shape the signal of either poor recording, poor room or poor sound in general.

In your case with your integrated amp UNFOTUNATELY you don't have poweramp input terminals while having fixed or variable output ones. So your EQ options explained bellow will work if:

1. You decide to replace your amp with one having pre-outs and amp inputs separate.
2. Either DIY or professional upgrade to have poweramp inputs
3. Purchasing separate poweramp and using your integrated as a preamp(use fixed outs)
4. If you're using only ONE source, than you can connect EQ between source and one of the line inputs. Otherwise you will have to reconnect your EQ to different sources manually by pulling wires.

If one of four above conditions are met, enjoy to continue reading following:

Connect EQ preamp section(or separate preamp) -> EQ -> poweramp section(or separate box amplifier). So all three components will serve it's purpose. EQ won't be your preamp, but will be your outboard tone control board. Vintage EQs designed for home audio may be one of your best bets and you should shop for one offering bypass or simply bypasses signal when not powered on. The pro-audio studio mixing ones can work as well. Most of them have TRS balanced outputs/inputs which may require you to shop for wires with TRS/RCA plugs to fit your amp/pre.

A simple example could be found herehttp://www.sweetwater.com/store/detail/231S/ where you can see a simple pro-audio EQ with 1 set of XLR in-outs and TRS in-outs in which case you can simply purchase these or simpilar cables: http://www.bhphotovideo.com/bnh/controller/home?O=&sku=483167&is=REG&A=details&Q=

The EQ in the above example is one of my favorite in its capabilities for great home audio playback and it has a bypass switch. It also has gain settings and can boost up the gain of your preamp in case if you're driving low-sensitivity amplifier or your phono setup is totalling less gain than line components.

Hope that helps.
FWIW, and equalizer is IMHO best used when it reduces the frequency output such as you seem to need, not to increase the signal strength as seen by your amp.

Consumer equalizers usually have 10 frequency centers spaced over the frequency range and each of the 10 divisions cover one octave (but it does not offer control of the width of the frequence it affects which, depending on the slope of the center's fall off, will overlap with the adjacent frequency control. This produces a rather broad dip (or increase) in the frequency response. I suspect that it would not be suitable for solving your issues.

For example, consider that you have a ringing in your hearing around 5K hz. A 10 octave equalizer would have centers an octave apart at 3200hz, 6400hz, and 12800hz. In order to reduce the FR at 5K hz you would also be depressing the FR at 3200 Hz and 12800 hz and your sound would take on a dullness to which you might object. It is possible that a 1/3d octave equalizer might be more helpful, as well as more expensive, for the obvious reason, but more complex is not necessarily better, because you may have more options but you still have less control over the width of a specific frequency.

I'm assuming you have problems which have a much narrower (than an octave) FR issue and that is where the parametric equalizer comes in. While one may have only 3 frequency center controls it has the capability of narrowing the width of the frequency response and minimizing the effect of a reduction at that frequency to the response of the frequencies surrounding it. Except for the effect on that frequency the presence of the equalizer sound not be heard. These are the most expensive equalizers.

Re equalizer insertion putting it between your amp and preamp should not be a problem unless you use it to increase signal strength substantially. Not your problem I think. Using a digital equalizer seems to be a good alternative to an analogue one but I have no experience using one. Its is something to consider.

Hope that helps a bit.
Before deciding on an EQ type I suggest that you get a simple test disc that has 1/3 band octave test tones. Play it and take notes of which frequencies are a problem for you. If you find that there are only a few bands that are an issue than a parametric is best as you can adjust the EQ to those specific frequency's as well as narrow or widen the band as needed. OTOH, if you have more than a few bands that are an issue than a 1/3 band per octave EQ will give you the control you need.

HTH and good luck.
Hi Broadstone

examples...
1. one octive EQ, no control for 5K Hz
http://www.rane.com/me15s.html

2. 1/3 octive, has control of more frequencies including 5K.
http://www.rane.com/me30s.html

Regarding our earlier discussion, the Rane ME30S was what I was considering since my rig is analogue.

(Getting the test disk is a terrific idea).
Hello,
I have a vintage Luxman G-11 equalizer. I believe this retailed for over $500 back in the late 70's. I sent it to a tech about 7 years ago and had it completely recapped, brought back to spec at a cost of $325. It's a quality piece. I used it in my prior house having bad room acoustics. No longer needed. I never bothered to post it here since I figured it would never sell. As others noted not much demand for EQs these days. Please contact me if your interested.
Good luck
Broadstone, don't be intimidated by the technical part, devote one day to studying the theory of an EQ and you'll have it mastered.

Behringer seems to be popular among audiophiles, maybe because it's digital. But the signal still has to be converted to analogue out to the amp.
A Behringer may have a longer learning curve but take a look at this one.

http://www.behringer.com/EN/Products/DEQ1024.aspx
(Sold at Amazon cheap)

I'd like to know what you decide in the end since I still am considering adding a unit due to my hearing problem.
Do not make apologies for an EQ. If you get better sound from such, give it a rest. Often in audio we follow rules that are really meant to be broken. If it sounds good, its okay. Our ears and rooms are different, so go with what sounds best, not what the rules tell you is acceptable.
Lowrider57, you mentioned hearing loss. Best you find a good audiologist and find out exactly the problem you are having. That will give you a better idea of whether EQ will help. I've been hearing impaired all my life, wearing hearing aids, that are programed to my hearing loss. Yes, EQ'd.
Buconero117, thanks for your reply, but Broadstone and I discussed this in an earlier thread. I also have hyperacusis and tinnitus, but not as severe as his. I've seen the ENT, audiologists and have been diagnosed; I'm now seeing a Neurologist who specializes in this area (since the pain signals originate in the brain).
BTW, the way I've dealt with it is by tube rolling, cables, and more room treatments.