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Ahhh--Problem solved. Adding a REL sub-bass unit...

I'm wondering how many audiophiles have given up on loudspeakers preamturely, or have gone down the rabbit hole of cable swapping to "fix" an issue with their speakers.  

I grew up hating subwoofers and home theatre.  I still haven't come around fully to home theatre.  I've warmed up though.  I've had my own issues with otherwise great loudspeakers, including a pair of Klipsch Forte IIIs.  I was very frustrated as I'm feeding them from a respected tube integrated, I've tried them with a 300B amp, and I've toiled over positioning.  

The issue that I was having was the mids and highs were dominating in my room--despite the size of the woofer and passive radiator. Some recordings were just too bright.  Sometimes I felt the speaker, however "alive" and dynamic was not imaging well, needed soundstage help, and so on.  

I hate to say the REL T9i I threw in the mix today is a panacea because there's always stuff to tweak.  Yet I have experienced this before with a Sumiko subwoofer.  Adding one to the mix and dialing it in so that it's barely audible has brought everything into focus.  Everything is more relaxed and energetic at the same time.  

I'd say that the REL is a room tuning device above all.  I have a larger room (I think it's 15 wide, 24 long and 10 high--in feet).   I'm not sure how much I'd have to spend or what different choices would solve this otherwise.  From a guy that used to reject subwoofers out of hand (my bias came from the 90s home theatre craze) I think that they might be necessary in the lion's share of systems with the lion's share of speakers.  To say, "you don't need a sub" with speakers might be true depending on your room, but I also think in most situations you are missing out on what they can do for so many criteria that are not necessarily in keeping with adding bass--e.g. soundstage, focus, imagine, fullness, taming treble, etc.). 

Finally, I really wish that I could try some other brands as many audiogon members recommended so many respectable names.  I ultimately went with REL because of its philosophy, my similar experience with a Sumiko sub (within the family of REL or somehow related), and the high frequency input connections. 
128x128jbhiller
ieales's avatar
ieales
1,201 posts
 
What do you recommend for a single capacitor that is "plug N’ Play"?

This image shows the circuit topology of hi pass

f = 1 / (2πRC)

f in Hz
R in Ohms of amplifier input
C in Farads of series cap

C = 1 / (2πfR)

This calculator will do the math. Scroll down to the calculator. Select Calculate Capacitance, enter amp input R & corner frequency. Calculation is pF. Best dielectrics are Teflon, polystyrene, polypropylene in that order and descending cost.

Parallel if you want to exact frequency, but ±1nF is close enough for most amps except those with very high input impedance. If you want to go nuts get an LCR meter and match as tight as you like, but realize the speakers are not that close, especially at the bottom!

This image from http://www.ielogical.com/Audio/#SmallestThings shows how to assemble.

You feed the full range to the sub, using its controls to roll out the highs and feed the filtered side to the mains.

When connecting for first time, disconnect mains from amplifier and turn subs all the way down. Slowly bring up subs with program playing. Should be just low end. Turn off program. Measure amp Output voltage. It should be nearly 0mV.

PM any questions.
wolf_garcia
6,737 posts
 
Rolling the bass out of the mains is unnecessary as the mains were likely designed to run full range, and in my experience with a few differing speakers used with my 2 RELs, that's simply a better sounding way to go. My 8" and 10" RELs match extremely well with the 12" bass speaker in my Heresy IIIs, with no phase issues (why would there when the phase is adjustable and the subs are barely in the same frequency range as the main speakers?). I don't think the avalanche of technical worries heaped on those deciding to use a sub or two is helpful really. I test my mains with a testing CD to decide where the bass becomes reticent, move the subs around until things sound great in my listening spot, and only change the sub levels from time to time to suit my mood or deal with too much or too little bass in a recording. Easy.
ieales's avatar
ieales
1,201 posts
 
Ouch! on so many levels.

Low end is always the poor stepchild as it conflicts with parameters necessary for higher range of driver.

Phase controls adjust at single frequency. See http://ielogical.com/assets/SubTerrBlues/PhaseControl.png at http://ielogical.com/Audio/SubTerrBlues.php/

Smaller sub than main driver? Really!
Different sub models? Really!

Testing CD and no instrumentation? REALLY!

Easy == compromised.

I'd have to hear it to be convinced.
jbhiller's avatar
jbhiller OP
1,445 posts
 
+1 as to what Wolfe said. 
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