Magnepan LRS Speaker Review

[Heyu]

Sure, give it a try. There is no one perfect setting. It’s going to vary depending on one’s setup/room.

Ever

I would not. That is the roll-off frequency, but large bass signals will cause it to distort very heavily. I usually roll off speakers an octave, or at least half an octave, above the -3 dB point, and panel speakers are generally worse than conventional speakers for distortion at low bass due to the high signal levels and limited panel excursion (especially with smaller panels such as the LRS). Look up "equal loudness curves" and you will find bass signals are often 10~100 or more times larger than midrange signals.

The counter is that the distortion, which can reach 10's of percent, may make the speakers sound "fuller" since the distortion is harmonically related to the signal (though intermodulation distortion in real music is not!) and easier to hear since it is higher in frequency than the fundamental.

I should play with 60 to 80 then?

 

[DonH56]

Ever

I should play with 60 to 80 then?

I would not go below 80 personally but it depends upon you, where your sub(s) sit(s), and your room. I would try 80 to 100 Hz. Actually I get tired of endless tweaking and would set it at 80 Hz and, if it sounds OK, forget about it and enjoy them.

 

[LTig]

Ever

I should play with 60 to 80 then?

I would not go below 80 Hz. See @DonH56's posting. Try also 100 Hz. The higher you go the louder you can play or the less distortion you get.

Edit: @DonH56 just beat me.

 

[Heyu]

I would not go below 80 Hz. See @DonH56's posting. Try also 100 Hz. The higher you go the louder you can play or the less distortion you get.

I'll try that. Last night it was around 160 with low pass off. I'll have to turn it on and play with the crossovers.

 

[LTig]

I'll try that. Last night it was around 160 with low pass off. I'll have to turn it on and play with the crossovers.

Make sure you do use a high pass filter for the LRS, otherwise you will not profit from lower distortion or higher SPL.

 

[Saturn94]

Of course what you like to play and how loud you like it is a factor as well. If you like bass heavy music played loud, a higher crossover frequency would be better. If your taste is chamber music at lower levels, then you can get away with, and may even prefer, a lower crossover frequency.

Again, you‘ll have to experiment.

 

[Heyu]

Make sure you do use a high pass filter for the LRS, otherwise you will not profit from lower distortion or higher SPL.

Oh really? Sub has a variable low pass filter. For high which one is good and how do I use it/work?

 

[LTig]

Oh really? Sub has a variable low pass filter. For high which one is good and how do I use it/work?

Either the sub has a high passed output for the LRS (or the power amp which feeds the LRS), or you need some other means to high pass the line level signal which feeds the power amp of the LRS, like a Mini DSP or an analog/digital line level crossover. Another possibility is to use an AVP.

 

[Saturn94]

Make sure you do use a high pass filter for the LRS, otherwise you will not profit from lower distortion or higher SPL.

Good point. I should have clarified the use of a high pass (as well as low pass) filter in my posts.

 

[Heyu]

Either the sub has a high passed output for the LRS (or the power amp which feeds the LRS), or you need some other means to high pass the line level signal which feeds the power amp of the LRS, like a Mini DSP or an analog/digital line level crossover. Another possibility is to use an AVP.

The zpre3 preamp manual mentions to use the sub low pass since the zpre3 sub output is in full range. The sub has only a variable low pass filter and the Parasound hca 1500a amp I have no idea.

 

[Saturn94]

The zpre3 preamp manual mentions to use the sub low pass since the zpre3 sub output is in full range. The sub has only a variable low pass filter and the Parasound hca 1500a amp I have no idea.

It doesn’t appear that preamp offers any bass management or a high pass filter. I believe you can buy external high pass filters that you can connect between your preamp and amp so a full range signal isn’t sent to the LRS.

 

[Heyu]

It doesn’t appear that preamp offers any bass management or a high pass filter. I believe you can buy external high pass filters that you can connect between your preamp and amp so a full range signal isn’t sent to the LRS.

It has a bass level +/- or flat but that's for taste not to filter.

 

[Heyu]

I played with the crossover and closer to 160 it's distorted and boomy. 90hz is just right and 80. Below that bass is thin.

 

[Heyu]

It doesn’t appear that preamp offers any bass management or a high pass filter. I believe you can buy external high pass filters that you can connect between your preamp and amp so a full range signal isn’t sent to the LRS.

What external filter do you suggest and at what frequencies is the cutoff?

 

[Heyu]

The way it works is with my subs variable low pass filter it filters high frequencies and with a high filter it filters low correct?

 

[DonH56]

Low pass = passes low frequencies, rejects (reduces, suppresses) high frequencies
High pass = passes high frequencies, suppresses low frequencies

 

[Saturn94]

What external filter do you suggest and at what frequencies is the cutoff?

Unfortunately, I don’t have any experience with external crossovers/filters. Check out this thread. It might be helpful.

FMOD high pass filters?

Does anyone have first hand experience with these? https://www.hlabs.com/products/crossovers/index.htm Do they actually work as advertised? Any attenuation, distortion, noise issues? I am mainly interested in an inexpensive way to filter out bass at line level (RCA) going from preamp to my...

www.audiosciencereview.com

 

[Heyu]

I played with the low pass filter on the sub and 40Hz to 60Hz sounds thin but from 70Hz to 80Hz is great bass.
Above 90Hz the sub seems localized. Is this because the sub is also doing the higher frequency?

 

[milosz]

I played with the low pass filter on the sub and 40Hz to 60Hz sounds thin but from 70Hz to 80Hz is great bass.
Above 90Hz the sub seems localized. Is this because the sub is also doing the higher frequency?

A 90 Hz sound has a wavelength of 12.5 feet (3.8 m) so it's unlikely you can localize a 90 Hz tone from a subwoofer.

Assuming the crossover is typical 24 dB for a simple DSP application, there will be some midrange coming out of that sub, more and more at higher and higher crossover frequencies.

What's also likely is that the harmonics of 90 Hz are loud enough to be heard when this subwoofer is reproducing 90 Hz. Harmonics of 90 Hz can be localized by human hearing. 180 Hz not so much, but like the 4th harmonic - 360 Hz - or 5th harmonic - 450 Hz - have shorter wavelengths and also the ear is much more sensitive to sound at 450 Hz than it is at 90 Hz. The woofer cone in the sub may well have resonances up in this region or even higher - and these spurious sounds add to the ability to localize.

 

[DonH56]

I played with the low pass filter on the sub and 40Hz to 60Hz sounds thin but from 70Hz to 80Hz is great bass.
Above 90Hz the sub seems localized. Is this because the sub is also doing the higher frequency?

As @milosz said the crossover is not a brick wall dropping to zero at 90.0001 Hz; there is likely quite a bit of energy extending well past 100 Hz making the sub easier to localize.

Magnepan's LF corners can be a bit optimistic, especially since the room and speaker/listener placement heavily influence the response. That is probably why the bass sounds thin with a lower crossover; the LRS is not reproducing the deep bass.

IME/IMO - Don