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Discussion Starter · #1 ·
Ok I've been reading threads and manuals and still don't completely understand the difference between max output and max Ext?


I know their is a 4db difference and max output only goes down to 20hz I think. But can someone give me a full explanation (in newbee terms what is actually happening)


If max Ext drops 4db cant I just raise thr over all volume of sub 4db? Also do I need to recalibrate my system when changing modes max Ext to max output
 

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The difference is maximum clean output before distortion sets in. Max output mode has a higher threshold of clean output ability than max extension mode, except below it's tuning point.


The volume of the port is a factor in tuning the low frequency extension of any ported subwoofer. Hsu lets you change the port volume, but there are trade-offs. The subwoofer's driver partly relies on internal air pressure as mechanical damping to prevent over-excursion and bottoming out. Port volume determines the force of this internal pressure by regulating how swiftly the air can move in and out. However, below a certain frequency the port does not create enough resistance to produce sufficient internal air pressure against the driver. Here the electronic limiter must be used to filter those oscillations which the ports do not offer enough protection against.


The larger the port volume is on the sub means the higher the frequency the driver can not oscillate under before risking over-driving and damage. Correspondingly, small port volume offers less airflow and therefore greater internal pressure and more protection from being over-driven, so the driver can play back lower frequencies safely. However, as a consequence of that small port volume, the driver is held back by that stronger internal pressure from oscillating as greatly at higher frequencies as it could be with larger port volume.


So you see, by adding a second optional port and ME/MO switch, the Hsu design lets you have your cake and eat it too, it just won't let you do both at the same time. It's a clever way to let the driver reach it's potential, yet also allowing the choice to have real output at subsonic frequencies as well.


Sorry for the long-winded explanation, I hope it wasn't too convoluted. By the way, you don't really need to rerun audyssey or however you calibrate your system as long as you know the SPL difference between the two modes. You could just add or subtract that in the receiver's subwoofer level if you want to keep everything flat.
 

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Discussion Starter · #3 ·
Thanks, that gave me a good idea on how it works!


How much is the gain in max output? I'm guessing it depends on the room?


Also , if I have it on max Ext how do I know when it's distorting? My receiver does not have EQ for sub , is the built in pink noise calibrated at 75db good enough for my sub?
 

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I don't know how much more gain you get in max output, I think I read somewhere that it's 5 db, but I'm not certain. It'd be best to ask Hsu to be sure. Room will always affect loudness, but I am talking anechoicly.


It'll will be hard to hear when it's distorting if you don't know what to listen for. Really it depends on the material being played back, if you know what its supposed to sound like, and hear something else, then it's distorting. Distortion is much easier to hear in the higher frequencies. As for the pink noise, it sounds like it'll do. If you want to be a perfectionist, buy a sub EQ (some of which cost more than the sub itself). I would just get it to where it sounds good and enjoy the music, unless you notice some particularly grievous nulls and peaks which your receiver's room correction isn't correcting for.
 

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Discussion Starter · #8 ·
Ok, but what does that 4db increase mean?


Does it mean everything is just gonna be 4db louder therefore less stressing? does it mean the sub won't hold back volume therefore giving you volume?


Is it 4db across all playable freq?
 

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Quote:
Originally Posted by stang323 /forum/post/19577397


Ok, but what does that 4db increase mean?


Does it mean everything is just gonna be 4db louder therefore less stressing? does it mean the sub won't hold back volume therefore giving you volume?


Is it 4db across all playable freq?

Since you will sacrifice extension in the max output mode, you will gain about 3-4 dbs across the 20hz-up freqs. You are relieving it from 20hz-down, so the sub will be able to play louder the higher freqs...

Yep. it will sound much more effortless/cleaner from 20hz-up(most likely, and with less port noise too)
 

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Discussion Starter · #10 ·
Ok, sorry for my newbeeness guys but one more question...


So at the end both mode Max Ext and max output should be play similar volumes (calibrated each of coarse to 75db) but max output having more reserve power for those reference volume demos
and sounding less force with the sacrifice of lower end?


Thank you guys for dealing with me! Cause I knw I wouldn't be able to, lol
 

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Stang, you got it right. There won't be a big difference in those modes unless you really crank the sub to it's limits. I hardly ever push my subs that hard so I just leave mine on max extension mode.
 

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Quote:
Originally Posted by stang323 /forum/post/19579659


Ok, sorry for my newbeeness guys but one more question...


So at the end both mode Max Ext and max output should be play similar volumes (calibrated each of coarse to 75db) but max output having more reserve power for those reference volume demos
and sounding less force with the sacrifice of lower end?


Thank you guys for dealing with me! Cause I knw I wouldn't be able to, lol

Yep. You got it!
 
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