Midrange and imaging issues with Vantage

[Ziba]

Hi everyone,

I've been lurking around this forum for about a year and I just finally decided to register. I've been playing around with my setup for a while, but I haven't been able to get my system to sound the way I would like it to.

Basically, the two main issues are:

1) lack of midrange clarity (eg, voices sound muffled and have a "nasal" quality); and
2) lack of imaging.

I've tried several things to fix my problem, including playing with every what seems to be every permutation of speaker placement I could think of (with REW measurements) and using acoustic absorption (broadband panels and corner bass traps). Then, the other day, I inadvertently noticed that cupping my hands around my hears improved the sound quality immensely! Voices finally sounded lifelike and imaging snapped into focus. I could hear every instrument separately in the space with great definition.

My setup:

Digital source: Jriver Media Center into Cambridge Audio DacMagic plus
Preamp: Audiolab 8200A preamp section
Amp: Classe CA-200
Speakers: ML Vantage

Room dimensions are 24' x 12' with a drop ceiling at 7.5' and hardwood floor. Listening position is at 12' from front wall. Speaker placement is currently 48” from front wall and 36” from side walls.

Any help would be greatly appreciated. Thanks!

 

[Rehan Azim Hashmi]

I suspect your preamp is the culprit that is holding back your system from producing great sound. Audiolab is not in the same league as Classe and ML. Besides not being of the same caliber there may be a mismatch between the power amp and preamp.

If possible buy a preamp from Conrad Johnson. Entry level preamp price ranges from $1.8K to $ 2.3K. Also if possible search for a better DAC than the one you have. Hope you are employing reasonably adequate speaker cables and interconnects.

The mismatch between preamp and power amp is related to both their impedance. Please correct me if i am mistaken, for i do not want to mislead, that input impedance of power amp may be at least 100 times the output impedance of the preamp. Both measurements in ohms.

Hope other members will also contribute their thoughts on the issue.

 

[Bernard]

The first thing I would do is check the polarity of the speaker cables. Make sure they are connected the same way...i.e. ensure the speakers are not out of phase with each other.

 

[twich54]

Zeba,

Welcome, outside of Bernard's and Rehan's suggestions I'm curious, how old are your Vantages ? Are you the original owner ?

 

[timm]

I think you just need to sit there with your hands cupped behind your ears. . I wonder if you are getting side reflections from the walls? My guess is your absorption is on the front wall? Could you attempt some blankets on side wall just temporarily to see if that alters things? You have an expanse of hardwood floor. Any area rug? How is it at lower volume - better or worse? I assume u have them on the short wall??

 

[Ziba]

I suspect your preamp is the culprit that is holding back your system from producing great sound. Audiolab is not in the same league as Classe and ML. Besides not being of the same caliber there may be a mismatch between the power amp and preamp.

If possible buy a preamp from Conrad Johnson. Entry level preamp price ranges from $1.8K to $ 2.3K. Also if possible search for a better DAC than the one you have. Hope you are employing reasonably adequate speaker cables and interconnects.

The mismatch between preamp and power amp is related to both their impedance. Please correct me if i am mistaken, for i do not want to mislead, that input impedance of power amp may be at least 100 times the output impedance of the preamp. Both measurements in ohms.

Hope other members will also contribute their thoughts on the issue.

I agree. The preamp and DAC are indeed the weakest links. The preamp upgrade will hopefully happen within the next year. I'm looking to get a matching Classe preamp, but I will certainly consider CJ. Before doing so though, I would like to make sure that this will significantly improve the sound. For some reason I have a hard time imagining a preamp swap making such a significant improvement, but that's just from a lack of experience with various preamps on my part.

Regarding the possible mismatch, the output impedance of the Audiolab preamp is 100 ohms vs 75 K ohms for the input impedance of the Classe CA-200. I assume this constitutes an “acceptable” ratio, does this make sense?

Cables are kind of all over the place.... Interconnects are Transparent Audio and MIT, speaker cables are Audioquest Rocket 88, and power cables are Nordost, Transparent Audio and Cardas.

 

[Ziba]

The first thing I would do is check the polarity of the speaker cables. Make sure they are connected the same way...i.e. ensure the speakers are not out of phase with each other.

Good point. They are definitely in phase.

 

[Ziba]

Zeba,

Welcome, outside of Bernard's and Rehan's suggestions I'm curious, how old are your Vantages ? Are you the original owner ?

I'm the second owner. Serial number suggests they were manufactured in 2008. Is there a way to tell if they need to be replaced?

 

[Ziba]

I think you just need to sit there with your hands cupped behind your ears. . I wonder if you are getting side reflections from the walls? My guess is your absorption is on the front wall? Could you attempt some blankets on side wall just temporarily to see if that alters things? You have an expanse of hardwood floor. Any area rug? How is it at lower volume - better or worse? I assume u have them on the short wall??

Or even better, I could wear a pair of Earglasses!

Panels are placed at first and second reflection points. There are no panels on the front wall, only two 2' x 4' bass traps (4” thick) mounted in each corner, floor to ceiling.

I've tried adding an area rug, but it made very little difference to me. Sound is worse at low volumes, but it improves somewhat at higher volumes. I typically listen at low to moderate levels.

You are correct, speakers and electronics are placed along the short wall.

 

[Hocky]

It sounds like either a set up problem or something in your chain is failing. It isn't because your preamp isn't "good enough." What do the measurements look like?

 

[Bernard]

I wonder if the previous owner messed around with the insides, trying to "improve" the speakers. You could take a peek inside them, BUT ONLY IF YOU KNOW WHAT YOU'RE DOING, CONSIDERING THE LETHAL VOLTAGES INSIDE.

In case the previous owner did open them and screwed up, try reversing the connections to one of the speakers.

 

[timm]

the reason I thought room issue is because you said that the cupping of the ears seemed to fix the issue.... so I wondered if that was eliminating unwanted reflections?

Also assume you are going pre 1 or pre2 outputs to the amp?

 

[Ziba]

It sounds like either a set up problem or something in your chain is failing. It isn't because your preamp isn't "good enough." What do the measurements look like?

Frequency response is moderately stable, with a range of 10 dB between 200 Hz – 10kHz. Bass response shows significant dips at 65 Hz and 150 Hz.

I wonder if the previous owner messed around with the insides, trying to "improve" the speakers. You could take a peek inside them, BUT ONLY IF YOU KNOW WHAT YOU'RE DOING, CONSIDERING THE LETHAL VOLTAGES INSIDE.

In case the previous owner did open them and screwed up, try reversing the connections to one of the speakers.

Interesting, that never even crossed my mind! When you say “take a peek inside”, do you mean open up the speaker cabinet to see how everything is wired to the woofer amp? Or do you mean how the panel is connected? Also, by “reversing the connections”, should I simply try to reverse the speakers cable connection of each speaker one at a time? Thanks for clarifying.

the reason I thought room issue is because you said that the cupping of the ears seemed to fix the issue.... so I wondered if that was eliminating unwanted reflections?

Also assume you are going pre 1 or pre2 outputs to the amp?

Yes, pre1 to power amp (and sometimes pre2 to powered sub).

 

[Bernard]

By "take a peek inside" I meant open the cabinets to see if both are connected the same way. But before you do anything like that, try reversing the connections to just one speaker (at the amplifier or speaker, not both) and listen. Leave the other as is; you don't have to reverse connections to it.

 

[Rehan Azim Hashmi]

I agree. The preamp and DAC are indeed the weakest links. The preamp upgrade will hopefully happen within the next year. I'm looking to get a matching Classe preamp, but I will certainly consider CJ. Before doing so though, I would like to make sure that this will significantly improve the sound. For some reason I have a hard time imagining a preamp swap making such a significant improvement, but that's just from a lack of experience with various preamps on my part.

Regarding the possible mismatch, the output impedance of the Audiolab preamp is 100 ohms vs 75 K ohms for the input impedance of the Classe CA-200. I assume this constitutes an “acceptable” ratio, does this make sense?

Cables are kind of all over the place.... Interconnects are Transparent Audio and MIT, speaker cables are Audioquest Rocket 88, and power cables are Nordost, Transparent Audio and Cardas.

K stands for 1000 times. So my guess yes this is a acceptable ratio. Your speaker cables, power cables and interconnects are all from reputable firms therefore i do not see a problem there. A matching preamp by the same power amp maker may be best. From what i have heard from various HiFi experts that conrad johnson makes very good preamps. Hence my recommendation of a preamp from this firm.

I feel for imaging to occur profusely everything has to be top notch in the audio equipment chain plus the audio recording itself.

 

[Bernard]

Impedance is not an issue here. The Audiolab's output impedance is 100 ohms, so the input impedance of the power amp should be at least 10,000 ohms...i.e. 10K. The Classé's is 75K, so there is no problem.

Personally, I would exhaust all other avenues before spending money on a new preamp. Your location just says Canada; if you live close enough to me, I'll bring my Audio Research preamp over to try it out.

EDIT: Ziba, (with all due respect) from your questions I have to conclude that your experience with electronics is limited, so DO NOT OPEN THE SPEAKER CABINET.

 

[Ziba]

No worries Bernard, I wasn't about to open up the cabinets!

So I reversed the cable connection to the left speaker only, the music clearly sounded out of phase. I reversed the right speaker only, same result. Then, I reversed both speakers at the same time, and strangely enough, it didn't sound all that different from when the cables are connected properly. I was expecting everything to sound completely out of phase, like on those test cd's, but this wasn't the case. Is this normal?

Turns out we do live pretty close to each other (didn't notice your location before), what are the odds! Thanks for offering your help, that is very kind of you, but I'll try hooking up my AVR to my amp first, just to see if it has any effect on the overall sound.

 

[roberto]

Hola Ziba. Absolute phase is difficult to listen. The size of a singer voice, being out of phase is big! When its is phase, the voice is precise and with the right size. The problem with the standards in the recording industry, they believe we can not tell the difference...this is not true. We can detect the phase with the size of the instruments. Sometimes we have a Spanish guitar very big, if you listen the other musicians that are playing with. You reverse the phase on both speakers, and you could have the guitar player with the right size, and the others too big. One mic is out of phase or two or three mics out of phase in certain recording with the other mics with the right phase. So, do not worry. What I do, is listen carefully the instrument or voice(s) with the right size at the stage, and I do not worry about the others. There are of course, many recordings with the right mics in phase. As an example, its hard to find a Chesky recording without the right phase. What I have from Chesky is right.

If you can not have a good stage on a certain recording, reverse the polarity on both speakers and listen again. You will be very happy to find out that that's the way to listen that particular recording.

Happy listening!

 

[timm]

curious.... if you walk right up to the speaker..... a foot away from the panel.... does the nasal quality go away? or does it stay? this still feels like a possible room issue to me???.... did you have other speakers in this position in the room that were planars / stats/ dipoles?..... If you move your seated position back and forth - closer / farther away from speakers does the nasal quality change?.... just some thoughts there......

 

[roberto]

I have to chime again...Nasal? For sure its coming from the electronics. One thing that I do love from Martin Logan, is when you have the right electronics and cables, the nasal is gone.

Its not the Vantage, other wise, all Vantange users will be making a big complaint about it, or any other Martin Logan model, because an electrostatic panel is the same, in the way that they are built.

In my experience with Martin Logan, many times this is a RF cable contamination from the source components.

Try different cables, if you are balanced, then try single ended, or vice versa. Try other speaker cable a listen...I will focus there. Phase is not an issue. If you have one speaker out of phase, then the first thing that you will notice is a big bass cancellation.

And absolute phase issue? As I said before, the Industry Standards believe this is not an issue. Philips, and Deutsche Gramophone, usually have at the recording, reverse polarity. A reason why usually we do not like their recordings...when you change the polarity in your system, you start to like those recordings...

Happy listening!