EQ ?

[Jim Cornell]

Hello freinds I got a Sansui 7 band equlizer for free and hooked it up for the hell of it. Im running the Klipschorns.

My question is if I run the EQ on a flat signal would I possibly cause harm to the Klipschorns?

I do believe that I am adjusting the flat signal, if im wrong let me know.

I can take it easy on my childrens ears with the adjustments.

I can see damaging the speakers with the bass and trebble advanced.

Regards Jim

[sunnysal]

I forget what amps you are running Jim but in general I think that EQs should be used primarily to attentuate certain frequencies to get the desired sound result, boost should only be added in VERY modest amounts when absolutely necessary. regards, tony

[Jim Cornell]

This is my audio 2005, lost a lot but kept the best IMO.

Regards Jim

[sunnysal]

jim, the reciever seems to have tone controls, so EQ might be overkill IMHO...however you have nothing to lose by plugging it in and seeing if you can come up with a pleasing result from tweaking around with the EQ...warm regards, tony

[homemade]

Your khorns will take any kind of boost in the low frequencies as you can stand!

I've had my homebuilt ones for yrs with a 10 now 15 band eq. with the bottom octave boosted 12db and the 125 range reduced aprox. 4db to tame the upper bass. All you're doing with the lower octave is raising the level to the higher efficiency horn loaded level. You're not demanding anymore from the woofer as you would if it were in a direct radiator enclosure. Now, I wouldn't suggest running 200 watts through it for hours that way but in a home in real life you couldn't stand the output before damage would be done. A 7 band eq. wouldn't give you the bottom octave control though that would needed for a flat response (maybe you like some 60hz kick though). I purchased a 15 band eq. on ebay for $28 plus shipping. It's a pro model with xlr and 1/4inch inputs plus rca inputs. The only problem I noted was last night when playing a dts encoded dvd I had to turn the volume close to 1/2 volume to get realistic levels and a little hiss was noted but not bothersome. If playing music at this level it would aproach 115 db at the listening postition and that's too much.

[Jim Cornell]

I like to be able to adjust the flat response, bass and treble set at o.

I did bump the bass a bit. the top end I brought down the mids a bit, for the kids and the treble is up just a tad.

I figured for free why not try.

If I ever get the money, Bob crites will redo my crossovers.

Always something in the way.

I hope ill never have to sell my audio to buy gas LOL.

Regards Jim

[Erukian]

eq's are also a band-aid solution for bad room acoustics, like how some rooms get a 40-60hz bump (talking like 10db) that once attenuated makes bass sound much better.

[Jim Cornell]

I never did have the propper room for these LOL, But there staying, eq helps better than a powerfull amp.

Regards Jim

[michael hurd]

"Your khorns will take any kind of boost in the low frequencies as you can stand!"

Depends, I would never try and run 12 db of boost no matter what. To each their own, but it is always better to cut than boost, as you run out of amplifier power very quickly, and stress components.

10 db in relation to 50 watts is 10 times the power, so 500 watts. With a large amount of boost, you can see that you need a very powerful amplifier with a speaker that could dissipate that power.

[djk]

"You're not demanding anymore from the woofer as you would if it were in a direct radiator enclosure."

Yeah, right.

Free lunch anyone?

"eq's are also a band-aid solution for bad room acoustics, like how some rooms get a 40-60hz bump (talking like 10db) that once attenuated makes bass sound much better."

Band-aid is a good description, it sounds different, not right.

The problem is in the time domain, and cannot be fixed with an EQ, even if it is 'digital'.

Fixing the room works (imagine that).

[sunnysal]

for those of us who have to leave our rooms largely "as is" tone controls/EQ help improve the sounds our systems produce. purists can rot...IMHO of course. tony

[Jim Cornell]

This unit is 60Hz -15Khz.

60Hz LOL heresy is 50? Makes me wonder if I am cutting frequency rather that adding, or adjusting anything.

This room has always sucked I have the hallway to the right, and an open area to the kitchen to the left, So all in all ive always had 14 feet of straight wall, 2 windows that are right next to the Klipschorns. this is why H/T never worked out here.

In the bedroom these sound superb, all 4 walls are there.

Its just the point of rocking out in the back room.

Regards Jim

[homemade]

DJK; your attitude is again getting the best of you. In direct radiator mode the khorn woofer has a 96 db efficiency and in horn loaded mode aprox. 104db. I'm saying that there is an 8db increase by horn loading, oh forget it-you're attitude prevents you from understanding me.

Michael, I don't think I could stand running my khorns at 50 watts and all of a sudden have a full volume sound at 35hz that would require 500 watts amp power.

I don't think I have ever run my khorns into distortion from overpowering the woofer. You could very, very, easily run 12db boost without any problem unless you like your music ear splitting level (above 115decibals).

[homemade]

DJK; call me at 620-983-2075 and we can talk (calmly). I don't know if you don't understand what I'm saying or are you just that way?

[John Warren]

----------------

On 3/27/2005 2:19:12 PM homemade wrote:

DJK; call me at 620-983-2075 and we can talk (calmly). I don't know if you don't understand what I'm saying or are you just that way?----------------

What are you trying to say? Are you assuming that the woofer in the folded unit can be bass boosted without any downside? Do you understand what is going on in the throat of a bass horn?

It's hell in there! "No free lunch" because the woofer is working against the substantiatal increase in radiation resistance afforded by the horn throat. Boosting the bass just adds to it's "woes". Concurrent with the added mechanical stress, the bandwidth suffers as does transient behavior.

djk brings up the point of fixing the "time domain" using "frequency domain" (i.e. EQ) adjustments. He is 100% correct, for all intents and purposes, it does not work.

[michael hurd]

"Michael, I don't think I could stand running my khorns at 50 watts and all of a sudden have a full volume sound at 35hz that would require 500 watts amp power.

I don't think I have ever run my khorns into distortion from overpowering the woofer. You could very, very, easily run 12db boost without any problem unless you like your music ear splitting level (above 115decibals)."

I guess it depends on your room, and how far away you sit from your speakers, as well as how loud you like to listen to music.

1 watt = 104 db @ 1m

2 watts = 107 db @ 1m

4 watts = 110 db @ 1m

8 watts = 113 db @ 1m

16 watts = 116 db @ 1m

32 watts = 119 db @ 1m

Spl drops by 6 db every doubling of distance from the speaker, thus if your seating position is 4m away, deduct 12 db from the 1m measurement.

119 - 12 = 107 db @ 4m from the speaker ( a little over 13 feet )

Unless you are a lot closer than 4 meters, you could use 32 watts, so 10db increase with an equalizer is asking the power amp to put out 320 watts.

[homemade]

I have mentioned it many times and no one has answered it: How many recordings put out full volume at 35 hz? Perhaps the 10db increase bothers the ones using smallish amps. I don't think I've ever heard my 60 watts/channel amp ever go into distortion at higher levels (perhaps my ears give up before the distortion sets in). DJK mentions a Q2 (6db increase at 31hz) eq to level out the bass response of his ported enclosures but no one give him any grief over the increased amp level required.

Here we have John Warren mentioning the increased resistance on the speaker because of the horn loading and increasing bass increases the stresses further. I thought that horn loading had no "play" in the lower frequencies below cutoff? Now it does? Does it or doesn't it? I sure thought it made some difference in the La Scala bass bin thread and I got blasted by suggesting it did.

I am through with trying to suggest anything in these threads anymore. I will continue to peak in from time to time because I enjoy the mods and what makes these speakers tick but it's getting too full of people who have very strong opinions and nobody apparently appreciates any of my comments. I have tried and related my experiences and people blast me for suggesting that perhaps one can eq. to gain bass and I can't believe the neg. response to that yet other people suggest it without any neg. response whatsoever. I'm going now to blow my woofers with my 60 watt amp!

[michael hurd]

You can do whatever you like, I still say that cutting is better than boosting. Cut everywhere else but what you want increased. IE: cut everything above 35 hz if that is what you are looking to increase.

With 60 watts, and 10 db of boost, you could not get over about 6 watts before the amplifier starts to " run out of gas ", and clip at the low frequencies.

For listening at low levels < 85 db, you may get away with that amount of gain. This also depends on the type of music that you are listening to. Electronica, and rock have a lot of demand in the low frequencies. Solo acoustic performances have basically nil.

[dragonfyr]

"Band-aid is a good description, it sounds different, not right.

The problem is in the time domain, and cannot be fixed with an EQ, even if it is 'digital'.

Fixing the room works (imagine that)."

DJK

DJK is ABSOLUTELY correct!

While most of the discussions focus on aspects of the frequency domain, few seem to be aware of the pre-eminence of the time domain with respect to so many of the acoustical qualities at issue, ranging from driver-driver interaction to speaker-speaker interaction to speaker-room interaction. And the majority of issues folks are attempting to address within the frequency domain cannot be resolved there until a minimum phase time state is achieved.

The ignore-ance of this fact is especially surprising within this forum considering the respect many have for significant individuals such as D.B. Keele and others who have emphasized this fact consistently for so many years, especially since the advent of Dick Heysers work and the advent of TEF analysis.

Below is the text of an article for which I am in error for reproducing as I cannot claim ownership. But if it helps to direct folks away from the repetitive nature of the same fruitless debates which characterize much of the site I think all will benefit greatly! It is an early article that has been amplified and further enlarged upon with time. But be forewarned! This idea and the broader idea from which it derives (namely the pre-eminence of the time domain in acoustics) will threaten many of your previously held golden ideas. It involves a fundamental paradigm shift. Many casually acknowledge it, but unfortunately treat it as simply an additional characteristic to look at as they continue to pursue their traditional focus, and miss the profundity of its importance. But it is the most fundamental component of the major advancement in acoustics that has recently (in the last 20 years) redefined the entire acoustics field. And if you are brave enough to explore this area, you can start with the AESs published collection of Richard Heysers works. Further information can be obtained by reading any of Don & (the ever-wonderful) Carolyn Daviss works, D.B. Keeles reviews, &/or attending ANY Synergetic Audio Concept (Syn-Aud-Con) seminars.

Also note that the article makes reference to reverberant fields which are applicable only to large acoustic spaces, and not to the typical (small acoustic space) listening room where the Lr times are not sufficiently large to constitute a reverberant field. But the article is also aimed at the (mis)use of EQ in live sound events as well.

And in a related aside, while I will acknowledge the advantages of high quality components, I am curious to know if the crossover mods mentioned on this site include phase correction for the acoustic origins of each of the drivers in the KHorn & LaScalas as determined by TEF measurements. If so, I would be interested to learn more of them. If not, I would be happy to assist in measuring the time domain offsets so that this correction can be incorporated. By aligning the acoustical origins in each of the drivers (refer to D.B. Keeles insightful articles and presentation regarding this topic!), a SIGNIFICANT improvement can be gained over the stock crossovers which do NOT feature this correction. In this way the standard crossovers may be greatly improved! This single mod will have a greater effect upon the intelligibility and imaging of the speakers than any other adjustment.

So, here is the article from the winter 1989 Syn-Aud-Con Newsletter:

What can an Equalizer Equalize?

The question What can an equalizer equalize? needs to be asked. Some claim to equalize the room. Is this possible? We think not.

When an electronic or passive equalizer is installed in between a mixer and a power amplifier we need to know that all it can equalize is the electrical signal being sent to the loudspeaker.

What comes out of the loudspeaker?

What comes out of the loudspeaker is called direct sound level, Ld. Early reflections from the floor, walls, and ceiling are called the early reflected level, Lre, and late-in-time, homogenous mixing sound is called the reverberant sound level, Lr.

When an electronic equalizer is employed it not only alters the Ld at the listener position, but also the sound power level, Lw, of the loudspeaker. {Note: Refer to Sam Berkows articles referring to the need to reduce a subwoofers crossover point with increases in gain! http://www.prosoundweb.com/install/transcripts/samchat.html} This in turn affects Lre and Lr but has no effect on Lamb. The question over the years has been how much can I alter Ld without throwing the baby out with the wash? Experience has shown that the answer is not much. Certainly not enough to drop a specular Lre having a full frequency response.

The Audience Effect

The so-called audience effect came about by people looking at the sound fields with 1/3-octave real time analyzers. What an RTA sees is the total sound field level, Lt, which is the combined Ld, Lre, and Lr plus any ambient noise present, Ln. Adjusting a sound system to a uniform Lt may or may not result in a sound you would want to listen to. In many cases the floor reflection can cause an operator to misadjust the direct sound level, Ld. Then when the audience arrives and covers the floor the misadjusted Ld is more clearly perceived and we say the audience affected the system. Really? Think with me for a minute.

What can the audience do to affect Ld from a sound system? The answer, of course, is absolutely nothing. Therefore, it is clear that the audience can only alter Lre, Lr and Ln. Now, ask yourself the question how can an equalizer adjust Lre, Lr and Ln? The answer is that it cannot.

I would hesitate to mention such obvious facts except for the remarkable number of articles appearing to claim the contrary. The only way an equalizer can cause a change in Lre, Lr and Ln is to do damage to Ld in the process.

What Can Affect Lre

Loudspeaker directivity factor, Q, is the classic way to handle unwanted Lres. Using a loudspeakers directivity to stay off of surfaces producing unwanted reflective energy is also one of the most cost effective solutions. The second approach is to use either absorption or diffusion.

Electronic Directivity Control

The increasing use of precision digital delays (i.e., 10 usec per step in contrast to normal digital delays of 1msec per step) to correct mis-synchronized loudspeaker arrays, where the mis-synchronization has resulted in directional lobing of the loudspeaker, demonstrates the importance and validity of directional control. {Additionally, limiting overlap of adjacent sound fields also minimizes the superpositional effect upon sound fields as well.}

Good Engineering Practices

Today, thanks to advanced analysis in the hands of competent users, good engineering practice has become:

1. Adjust Ld by measuring it alone with a TEF analyzer.

2. Optimize the reduction of Lre, Lr, and Ln levels by means of controlled directivity and measured synchronization of arrays.

3. Fundamentally control Lre, Lr and Ln through traditional use of absorption, diffusion, and noise abatement techniques.

What Point Am I Trying To Make?

The point I hope I have made is that electronic equalization in the frequency domain cannot correct phenomenon in the time domain outside of the minimum phase period (i.e., a few hundred microseconds). Therefore, claims to do so should be rightfully regarded as ignorant utterances or else fraudulent in intent.

I hope that this has cause a few folks to stop and ponder.And rather then reject the ideas to pursue learning more about some of the more amazing recent developments in acoustics. This posted simply to aid in the understanding of those who are open to hearing it and/or to learning more regarding this aspect of acoustics.

One additional factor to consider: With an EQ, you employ LRC filters, and while non-inductive resistors will not effect signal phase, the L & C components most definitely do! In doing so, they modify the phase of the electrical signal and subsequently result in a change in acoustical phase, and the resultant signal superposition modifies the vertical and horizontal polar response (in its most extreme use (180deg out of phase), this is referred to as active noise cancellation!). The polar lobes will be moved due to the change in phase (and exacerbated by the superposition of more then one source!), thus moving the apparent anomalies but NOT correcting them! Hence, without addressing the initial acoustical source(s) into a minimum phase condition, the EQ will merely change the apparent effect, while Not correcting it!

[maxg]

Dragon,

Very interesting article - thanks for that. Raises some questions though..

If I have understood this correctly Ld is the direct sound from the system - independent of location, and, in broad terms Lre Lr and Ln and all incident to that production and due to the environment.

Therefore it is fair to say that Lre, Lr and Ln are all dependent upon Ld (as well as the environment).

This implies that changing Ld - as an equalizer does - will indeed have an effect on all the other parameters.

A given listener will hear the sum of Ld, Lre, Lr and Ln. Whilst the changes brought by an equalizer on Ld may not, in absolute terms be beneficial it seems to me that in the sum of the parts (Ld+Lr+Lre+Ln) it may well bring about the desired result.

Of course - I have no idea what I am talking about - but this is the impression the article actually left me - despite obviously being meant to leave a different impression.