Left and right speakers don't sound even at volume , help??

[stevenlevel 146]

Here's what is going on:

 

I own two pair of Definitive Studio Monitor 450's that have off axis tweeters and a side mounted 10" passive radiator to boost the main 6 1/2" bass drivers low end. They also each have a 1" aluminum dome tweeter that's been annealed(What ever that means?)

Sorry I can't post any pics for at least a few days to give people a better look at how they are setup but please try and picture this.

 

My 50" plasma is slightly offset in a corner to the right so it's not perfectly angled but this was the most effective place in order to have my main 450's (on the steel stands designed for them) to be placed at each side of the tv with the passive 10"ers aimed inward and the off axis tweeters set up to be on the left side of the left speaker and on the far right side of the right speaker.

 

Now a while back I posted about how bright these speakers are and they were so bright that it was suggested by a few that I place L-Pads on each side front speaker and also my Definitive C/L/R 2002 center channel speaker.

 

I went ahead with the project and added 3 L-Pads between the tweeters and the cross-overs of these 3 main speakers.

 

Now it seems like no matter what I do the right speaker seems dull, lacks mid-range and bass when compared to the left speaker.

 

If I go back and forth with the C-1 balance control the left speaker really seems to not only sound different but lacks some volume as well. Now I have a 2/200 watt digital display that's hooked up to my main hafler DH-500 amp and it shows that the left speaker is getting a equal signal or close enough to the exact signal the right speaker is getting.

 

If I adjust the L-Pads the speakers do not adjust the highs on a equal basis and this is obvious.  So here are a few questions:

 

Can L-Pads(variable resisters) have different amounts of attenuation at the same exact settings?

 

Can the left speaker that's right next to the wall but has the passive faced out away from the wall have it's sound boosted thus fooling my ears with the balance control all the way left or right?

 

It seems like when I do a simple speaker reverse that whatever speaker on the left side seems to play louder and have a better overall sound. Is this normal or am I hearing things? 

 

Could one cross-over just have a failing cap that's messing with the overall sound of the right speaker? 

 

I ordered new deep threaded screws, and new gasket foam to make sure the drivers and passive are all air tight as these are not ported speakers. I also several replacement drivers for both front speakers.

 

I plan on swapping out the L-Pad cross-overs with the cross-overs from the second pair of 450's and re-sealing all the drivers putting them back to brand new status and then simply use the C-1 tone controls to avoid that really bright pair of tweeters. 

 

I fear I made a mistake buying these Definitive 450's as I just can't understand how they could produce a speaker or speakers that are this bright, and really bothering me a great deal with certain music.

 

I tried several Graphic Equalizers and ended up selling every one as they just added distortion I didn't need.

 

I want my seperate component system to sound like it should with CD and vinyl playback and I'm doing my best to get these 450's to sound as good as they can.

 

The odd thing is that with the excessive brightness comes great upper and lower mid-range and fairly good lows. If this tweeter is tampered with I end up getting a dull, lifeless, and thin sounding speaker.

 

I listen to a lot of new vinyl and have begun a new collection. I find that when I play vinyl the sound with a Technics SL-Q3 and Black pearl MM cartridge that the highs are more even than when I play CD audio.

 

 

Some older CD's from early on in my CD collection sound tolerable, but all new fully digital recordings sound so bright I can't take it after a while.

 

Really sorry about this really long and messy post but I'm really looking for a way to get these speakers to sound good enough to last me a few more years and then I'll replace them with some good floor standing speakers that will not be too bright.

 

Please keep in mind these are $600+ a pair speakers retail that I picked up for $290 a pair about 3 years ago and bought them without even listening to them first based on the name and that my dad owns Definitive floor standing models from about 8 years ago that I really loved.

 

So I will listen to any suggestions or opinions anyone has and be grateful that anyone responded at all to this diatribe about my poor speaker choice that I should have know was too good to be true!

 

How DEFINITIVE  can sell speakers this bright and think they are audiophile class speakers at $320 (retail) each is beyond me and if I had any good sense back then I would have returned them right away!

 

Help..............

                     Help..............

 

If there is anything I can buy that can adjust these speakers without adding distortion I'm all ears

 

 

 

 

 

 

 

 

 

 

 

[Maddmaster 1,009]

 

 

Here's what is going on:

 

I own two pair of Definitive Studio Monitor 450's that have off axis tweeters and a side mounted 10" passive radiator to boost the main 6 1/2" bass drivers low end. They also each have a 1" aluminum dome tweeter that's been annealed(What ever that means?)

Sorry I can't post any pics for at least a few days to give people a better look at how they are setup but please try and picture this.

 

Now a while back I posted about how bright these speakers are and they were so bright that it was suggested by a few that I place L-Pads on each side front speaker and also my Definitive C/L/R 2002 center channel speaker.

 

I went ahead with the project and added 3 L-Pads between the tweeters and the cross-overs of these 3 main speakers.

 

Now it seems like no matter what I do the right speaker seems dull, lacks mid-range and bass when compared to the left speaker.

  

Can L-Pads(variable resisters) have different amounts of attenuation at the same exact settings?

 

Can the left speaker that's right next to the wall but has the passive faced out away from the wall have it's sound boosted thus fooling my ears with the balance control all the way left or right?

 

It seems like when I do a simple speaker reverse that whatever speaker on the left side seems to play louder and have a better overall sound. Is this normal or am I hearing things? 

 

 

 

The speakers you are asking about: 

http://www.definitivetech.com/products/studiomonitor-450 

 

1. Can L-Pads(variable resisters) have different amounts of attenuation at the same exact settings?

The answer is yes.

 

2. Can the left speaker that's right next to the wall but has the passive faced out away from the wall have it's sound boosted thus fooling my ears with the balance control all the way left or right? 

Speaker location definitely effects the sound, so yes. 

 

Some of the DefTech's do sound really bright. Especially the older series. As you have noticed, it depends on the source, source material (old verses new CD recordings; vinyl; etc). 

 

The speakers themselves may not be at fault. Check to make sure the  speaker connections are correct (plus (+) and (-) minus at the speaker and power amp). Just as a test don't physically move the speakers but swap the left and right connections at the amp. Does the unequalness move to the other side? If it does the speakers at not the culprit.

 

L-pad IMO can have strange effects on the sound. You are actually adding an unknown to (although connected after the crossover) the crossover network. You may have created a problem trying to resolve the other (brightness).

 

Check those few things and let us know the result. 

 

 

[fill35U 1,847]

Can L-Pads(variable resisters) have different amounts of attenuation at the same exact settings?

 

Technically, an L-pad is a *potentiometer*, a 3-terminal device. If you only use it as a variable resistor, that's a rheostat. You should use all three terminals on the L-pad, to minimize impedance differences seen by the crossover.

 

There are conflicting design criteria for choosing the resistance value: set at full driver voltage(max volume), the crossover will see the full value of the L-pad in parallel with the driver, which combined will always be lower than the impedance of the driver alone. Set at minimum driver voltage(no volume), the crossover will see only the resistance of the L-pad. Set anywhere in the middle will of course present an impedance somewhere in the middle. The crossover's cutoff point will change with the impedance it sees as a load. In theory not good, but seems to be no big deal in practice. But you do want to use an L-pad resistance that's not too different from the driver impedance to minimize these effects. 

 

If the L-pad has too small of a power rating, its resistance will change with high volume and time spent there, perhaps by a factor of two or more, affecting driver volume and again crossover response.

 

All that said, L-pads are usually of wirewound construction, which means they are capable of excellent precision and accuracy. If the L-pads are of identical part number, anywhere near appropriate value and application, and installed correctly, they should have no difference in audible effect when set to the same position. Even using just the ol' Mk 1 Eyeball. But for a sanity check, turn them both to the same setting, then measure their resistances. They should be within 10%, if not 5%. 

 

Can the left speaker that's right next to the wall but has the passive faced out away from the wall have it's sound boosted thus fooling my ears with the balance control all the way left or right?

 

As Maddmaster noted above, speaker placement can have a huge effect. Distance from the speaker to the nearby walls, differences in wall materials and coverings, reflection paths to the listener, distance from other speakers, angle of toe in, and proximity to other objects can all affect the sound volume, tonal balance, and quality. Luckily, with those stands, both your speakers should have the same height, tilt, and ceiling/floor reflections. 

 

The passive orientation, however, should have near zero audible effect. PR's are much like ports, but better in several ways. Like ports, they're tuned below driver resonance, and have a narrow bandwidth. But they don't suffer from turbulence, and thus are less localizable at high output. A PR will drop off its output around 12dB/octave, and so one tuned at 40Hz would be down at least 20dB by 160Hz. You're not going to localize anything from the PR's, unless you drove them really hard to generate significant distortion. Hearing that there's something wrong coming from the PR would be a good thing at that point, so you could prevent disaster... 

 

It seems like when I do a simple speaker reverse that whatever speaker on the left side seems to play louder and have a better overall sound.

 

What do you mean by "do a simple speaker reverse"? 

 

Is this normal or am I hearing things?

 

I would definitely trust your ears! OTOH, the simplest explanation is that your hearing is not the same between your ears, which is a common condition. Do you notice a difference if you listen with your back to the speakers? 

 

Could one cross-over just have a failing cap that's messing with the overall sound of the right speaker?

 

Always a possibility. Might want to check if there are current-limiting bulbs, fuses, or polyswitches that might have degraded or blown. Probably not easy for you to check, except by swapping crossover components and drivers between speakers. 

 

I tried several Graphic Equalizers and ended up selling every one as they just added distortion I didn't need.

 

A good quality graphic EQ in good condition should add negligible distortion. If you don't mind the computer interface, you might look into a MiniDSP unit.

 

Some older CD's from early on in my CD collection sound tolerable, but all new fully digital recordings sound so bright I can't take it after a while.

 

You're not alone, many people feel that sound quality has gone steeply downhill on more recent releases, for a variety of reasons. You might want to look into a Carver Digital Time Lens unit, or Carver CD player with DTL. 

 

[stevenlevel 146]

Thanks guys for the feedback.

 

As far as normal speaker swap, I mean just swapping them from left front to right front and vice a versa.

 

I'm beginning to think it's my hearing. I just turned 50 and I know I have sinus issues that I never knew about until about 4 months ago.

 

I was thinking about simply replacing the L-Pad cross-overs with the standard cross-overs in my second pair of 450's that I use for side surround sound.

 

I have had passives fail twice with this model of speaker and it's very obvious when they fail. They will make a popping sound unlike the normal 6 1/2" main driver.

 

I have replacement drivers and passives to use if a driver is bad. That's one good thing about Definitive I can say. There customer service is outstanding and they have sent me many replacement drivers/passives/ and even new rear binding posts over the last 4 years.

 

The speaker that sounds weak is always the right side which has a open doorway right behind it. The left side always just sounds much fuller with good midrange and really good low bass as well.

 

I made sure the phase was correct and double checked it as my dad taught me about how important correct phase is back when I was 14 and I put my very first system together.

 

He actually built the hafler DH-500 in kit form back in 1981 or 82 when he also bought the C-1 preamp I am also currently using.

 

The L-Pads are the best I could find at Parts Express and are rated at 100 watt mono if I recall correctly. It was the highest rated L-Pad available that they sold.

 

One is either off  by about 20% or my hearing is. I can get them even with the highs but the speaker on the left needs less gain than the right speaker does.

 

I was planning on replacing all the drivers and passives in both speakers but I ordered the #6  3/4" when I need #8 3/4" that were out of stock.

 

I ordered some nice gasket foam sealer to go around the 6 1/2"  and the 10" passive but I need the new screws as these at least a few of the screws on all 4 speakers are striped out but repaired.

 

My goal is to make sure the main front speakers are both air-tight and have new drivers as well.

 

However, as I mentioned I need some #8 3/4" course threaded screws before I can go down this path.

 

Once again thanks for taking the time to answer my questions as there were so many.

 

Seeing how when i swap the left and right with each other and the left speaker seams to sound better, it must be speaker placement with both the open doorway and the fact there is couch on the right side as well.

 

I hooked them up in a second bedroom that has nothing in it with the speakers in the best possible placement and they sounded perfectly even with a nice Denon receiver that I had in storage. 

 

So once again thanks for taking the time to answer all the questions I asked. You guys are the best at this site  

 

 

 

 

 

 

 

 

 

 

 

 

[zumbini 6,150]

 

 

....The speaker that sounds weak is always the right side which has a open doorway right behind it. The left side always just sounds much fuller with good midrange and really good low bass as well.

 

Seeing how when i swap the left and right with each other and the left speaker seams to sound better, it must be speaker placement with both the open doorway and the fact there is couch on the right side as well.

 

I hooked them up in a second bedroom that has nothing in it with the speakers in the best possible placement and they sounded perfectly even with a nice Denon receiver that I had in storage....

You answered your own question Steve. The wall on the left reinforces that speaker while the open doorway attenuates the other.

 

 

....I need some #8 3/4" course threaded screws before I can go down this path.....

Check your local hardware store. If they don't have them McMaster-Carr (online catalog sales) will. 

[Maddmaster 1,009]

That was a good learning experience. You've found first hand that speaker placement is critical and has an effect on sound quality.