Speak sound distoretd when playing bass heavy musics?

[m500]

I'm at a lost here. Please help me identify the problem that send my speaker to the land of distortion.

My Speaker sounded awesome when playing DVD concert from Charlotte Church or any vocal heavy music. But it'll take an 180 degree turn when I pop in a Rock/R&B or Rap CD. It sounded fine for the first couple of minuts and the whole thing just crashed.

I thought I have cured the issue when I replace my Int. Amp with NAD C352 and a brand new pioneer CD/DVD player but its started to happen again. I can hear the volume went dim when I watching sound effect heaving musics. Help!

1) Is this the issue with Amp? Does it not have enough backup power to power my 4ohm MB quart speakers?

2) Is this the issue with my AC outlet that can't offer enough power for my Amp?

3) Is this the issue with placement of the speaker? I wouldn't think it'll have this much dramatic effect on them?

4) Bad speakers? Not likely as this is the second pair the vendor replaced for me and the one I returned to them sounded superb now they have it sitting in their showroom.


At this point I really feel like seeking professional help to correct my issue before I go nuts. I have spend enough money in trying to correct the issue after I bought these speakers.

[E-Stat]

I'm at a lost here. Please help me identify the problem that send my speaker to the land of distortion.

Sounds like good ol' clipping to me. You're overdriving the amp. Where is your gain control when this occurs?

rw

[Wireworm5]

I think your problem is a combinations of two factors
1. Your amp cannot drive a low impedance load speaker
2. Not enough reserve power, and is clipping at higher volumes when requiring more power for bass freq.

My experience with terrible sounding bass was when I tried two different receivers to power the bass drivers on my Studio 100's in a bi-amp configuration. Neither reciever could drive these speakers. Problem was solved when I just used my Yamaha receiver, which can drive a low impedence load.

[m500]

Sounds like good ol' clipping to me. You're overdriving the amp. Where is your gain control when this occurs?

rw

This Occurs at only 20 - 25% on the volume. I replace the previous brand new Yamaha amp due to the same issue but at 80% volume which is not even louder then my NAD's 25% volume. But its the same situation.

[m500]

I think your problem is a combinations of two factors
1. Your amp cannot drive a low impedance load speaker
2. Not enough reserve power, and is clipping at higher volumes when requiring more power for bass freq.

My experience with terrible sounding bass was when I tried two different receivers to power the bass drivers on my Studio 100's in a bi-amp configuration. Neither reciever could drive these speakers. Problem was solved when I just used my Yamaha receiver, which can drive a low impedence load.

Wireworm5,
1.The amp I'm using its designe to drive low impedance load speaker. Where my last yamaha amp was not and that why I replace it with after 2 weeks of purchasing it.

2. This is want I'm thinking but I would of think its more then enough but I just don't have any more money and space for another Amp. Unless someone willing to loan me a high power 4ohm amp with 100+ wpc to test it out.

Here are the spec of my Amp, if it helps:
2 x 80W Continuous Power into 4 / 8 ohms
115W, 185W, 240W IHF Dynamic Power into 8, 4 and 2 ohms, respectively
PowerDrive™
High Current Holmgren™ Toroidal Power Transformer
7 Line Inputs, including Two Tape In/Outputs
All Discrete Circuitry
Short signal path from input to output
Bass and Treble Controls with Tone Defeat Switch
Main-amp Input & 2 Pre-amp Outputs
NAD Soft Clipping™
IR Input/Output
12V Trigger Output
Relay Input Switching
IEC Detachable Power Cable
Headphone socket
NAD SR-5 Full System Remote Control


Here is the spec for the Speaker I'm using:
* Impedance: 4 Ohms
* Frequency Response: 33Hz - 32kHz
* Sensitivity: 87dB
* Power Range: 110 - 180 Watts
* Crossover Frequency: 2.5kHz
* Dimensions: (HxWxD) 37.4"x 8.9"x 12"

[E-Stat]

This Occurs at only 20 - 25% on the volume.

The position of the volume control is entirely relative. Relative to the output of the source and the sensitivity of the amp or preamp. I once had a 320BEE and found that NAD amplifiers are unusally sensitive. Where many integrated amps require a nominal volt or so input to reach maximum output, the NADs require 0.25 volts. With my CDP, maximum gain occurred around 9:00 or 10:00 as well. Ideally, you would reach maximum gain somewhere around 1:00 or 2:00 to maximize the range of the control.

With my Sound Labs system, I have a pair of 350 watt tube mono amps. When I play something with first octave bass, I too have to keep the gain down somewhat to prevent clipping. Ironically, the more the dynamic the system gets, the quicker this occurs. Your speakers have about the same sensitivity as my U-1s.

I still think you're clipping beyond those levels.

rw

[bfalls]

NAD manufacturers very good amp/receivers, usually provide more than rated power. Unless you bought one of Yamaha's low-end units, I find it difficult to believe it couldn't handle the MB Quartz 4 ohm load. Yamaha routinely provide published specs for their amp sections in 8/4/2 ohms. The problem your experiencing is more likely from the MBQ's 87db efficiency rating. It requires twice the power to drive a speaker with an 87db efficiency than one with a 90db efficiency. Usually speakers in this efficiency range are driven by high-current, high-wattage (200W-300W) amps. If you routinely play your music/movies loud you may either want to get a higher wattage amp, or more efficient speakers.

[m500]

The position of the volume control is entirely relative. Relative to the output of the source and the sensitivity of the amp or preamp. I once had a 320BEE and found that NAD amplifiers are unusally sensitive. Where many integrated amps require a nominal volt or so input to reach maximum output, the NADs require 0.25 volts. With my CDP, maximum gain occurred around 9:00 or 10:00 as well. Ideally, you would reach maximum gain somewhere around 1:00 or 2:00 to maximize the range of the control.

With my Sound Labs system, I have a pair of 350 watt tube mono amps. When I play something with first octave bass, I too have to keep the gain down somewhat to prevent clipping. Ironically, the more the dynamic the system gets, the quicker this occurs. Your speakers have about the same sensitivity as my U-1s.

I still think you're clipping beyond those levels.

rw

I feel the same way too after I posted the specs. My MB Quart require RMS of 110 watt minimum to power them. If this is the case, how do I remedy them without getting another Amp. I already have a spare at home the 'Yamaha'.

[m500]

NAD manufacturers very good amp/receivers, usually provide more than rated power. Unless you bought one of Yamaha's low-end units, I find it difficult to believe it couldn't handle the MB Quartz 4 ohm load. Yamaha routinely provide published specs for their amp sections in 8/4/2 ohms. The problem your experiencing is more likely from the MBQ's 87db efficiency rating. It requires twice the power to drive a speaker with an 87db efficiency than one with a 90db efficiency. Usually speakers in this efficiency range are driven by high-current, high-wattage (200W-300W) amps. If you routinely play your music/movies loud you may either want to get a higher wattage amp, or more efficient speakers.

The Yamaha I was using is RX-V650 a Mid-Fi they call it. Its hardly high end but definitely not an entry line. Both option you suggested is out of my current funding situation. i would need to get rid of either one of them for the upgrade otherwise I'll have to send my kid to Public school instead of private. Money its tight right now as we started our shopping spread early. The little money I have left its for the year end vacation which I'm due for it for a long time. Any other alternatives.

[m500]

What can I do to determine if the lack of power is the main issue?

1) I thinking of taking the bi-wiring connection plate off to just power the top pair to see if there were any improvement?

2) Or routing the speaker output from Amp to a sub's speaker level input and then from Sub to speaker. Using subs adjustable cross over to cross out the BASS at 80hz in relieving the work for the amp to power the bass, therefore to provide more power to the speaker for HIGH & MIDs.

How much would it cost me to have a sound advisor to troubleshoots my set ups?

[E-Stat]

What can I do to determine if the lack of power is the main issue?

Got a friend with a larger power amp you could borrow?

2) Or routing the speaker output from Amp to a sub's speaker level input and then from Sub to speaker. Using subs adjustable cross over to cross out the BASS at 80hz in relieving the work for the amp to power the bass, therefore to provide more power to the speaker for HIGH & MIDs.

That's a similar approach I use in my HT system using a NAD T763, Polk RT-35s and a pair of powered subs. Offload the lowest bass output to the subs.

For systems at any price level, I heartily recommend spending fifteen bucks on Caig contact cleaner and use it annually on all contacts. Amplifiers dutifully attempt to amplify whatever signal is sent to them. Corroded and oxidized connectors tend to pick up RF which manifests itself as high frequency garbage that the amp must deal with. Look at your speaker wires. Is the copper still bright and shiny?

While this is an extreme case, here is some Monster cable I replaced in the power supply from my old electrostats. The sonic difference was apparent. If the wire is getting grungy, then spending another fifteen bucks on new wire could be beneficial. Don't make your amp work any harder than it should.



rw

[m500]

Got a friend with a larger power amp you could borrow?


That's a similar approach I use in my HT system using a NAD T763, Polk RT-35s and a pair of powered subs. Offload the lowest bass output to the subs.

For systems at any price level, I heartily recommend spending fifteen bucks on Caig contact cleaner and use it annually on all contacts. Amplifiers dutifully attempt to amplify whatever signal is sent to them. Corroded and oxidized connectors tend to pick up RF which manifests itself as high frequency garbage that the amp must deal with. Look at your speaker wires. Is the copper still bright and shiny?

While this is an extreme case, here is some Monster cable I replaced in the power supply from my old electrostats. The sonic difference was apparent. If the wire is getting grungy, then spending another fifteen bucks on new wire could be beneficial. Don't make your amp work any harder than it should.



rw

E-Stat,
I don't have any friends that have an amp that offer 100 wpc to drive a 4 ohm speaker. Most of them have Denon and Yamaha which won't offer any more power then my NAD in 4ohm load. The only one who is into high end has a Tube setup which its about 50 wpc the most with specific designed speaker for it. I doubt he'll let me borrow his tube amp. I know, I wouldn't but 50 wpc would do anything for these MB_Qs.

The speaker wires are 10 gauge from JBMAudio. I have them for just 2 month, so they are in perfect condition. I guess I'll try the first route first as it much easier and then get a sub to test the second alternatives.

[m500]

Thanks for all your help. I just found the culprit that cause all these problems. I was too cheap to invest on a pair of Monster audio spliter and have no patient to wait for it to arrive in the mail. So I went to the local audio shop and pick up some cheap $6.00 audio spliter they happen to have and that degraded my whole system to trash. I now pulled it out of my system and the sound quality has restore but still not much bass. Well thats just the way the speakers are designed. Thanks. my search for a good amp and a justifiable cost continues..