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Vandersteen 2Wq subwoofers with M5-HP crossovers - help needed

I have been happily using a pair of Vandy 2Wq subs with single-ended M5-HP crossovers for a few years now. My system was dialed in the way I like it (bass a bit on the full side, but still tight and defined). I just had my amplifier repaired and upgraded, and the new input impedance is 22k ohms vs. the 10k ohms before the upgrade. I followed the Vandersteen recommendation for the jumper settings in the M5-HP (6 and 7 only, "on" or not open), and the bass is just about MIA altogether. As per the Vandy web site, I disregarded the chart on the case of the M5-HP and followed the chart on the web site.  Because I am an idiot, I didn’t bother to mark down the settings of the jumpers prior to changing them. Anybody have any suggestions for me that will restore the bass? I am pretty sure the issue is the jumper settings. Thanks in advance!
bondmanp
hifiman5's avatar
hifiman5
1,611 posts
 
Did you try the 10k setting?

mr_m
1,087 posts
 
Bondmanp,
You mentioned dialing back one the efficiency knob back to 85db. Shouldn't you be going up to 86, 89, or 90db to produce more output from the 2Wq? That's what I did to mine to increase bass output. If I'm wrong, I have then set my sub incorrectly.
audioconnection
1,015 posts
 
Bond,
  the instructions below
 the part you missed that engaged the protection
 If you go to Vandersteen website under resources download the Vandertones make a CD or file
((((((((((((((((((((((((( turn preamp volume down.)))))))))))))))))))))
 track 27 is 1000 hz track 31 is 80 HZ get a Voltmeter set to AC Volts looks like a sideways s snake and connect probes clipped to amps speaker posts Red is Plus Black is Minus
Play track 27 and slowly raise preamps Volume up till Volt meter says 1 V AC then play track 31 if your dips are set right it should now read.707
 once you get it set a few days of run in should sound great again.
  JohnnyR
audioconnection
1,015 posts
 
What the sticker says is for 100 hz
one setting down is 80 hz
 The meter confirmes the above procedure.
Every time you change setting start again trk 27 with 1 v .ac.then use track 31 for 80 hz.
 Call me later if you're going nuts.
 JR 
bondmanp OP
1,465 posts
 

@audioconnection - I started with the preamp volume set to zero, and the protection circuit still engaged, before I had a chance to increase the volume. I am one of those few who RTFM.


I began to think that there was something wrong with the M5-HPs, and they would have to go in for service (lithium batteries installed in 2012, so probably not two dead batteries at the same time). I retained the in-line 10K filters I had used prior to acquiring the M5-HPs for such a situation. I put them in and got more bass out of the 2Wqs than with the M5-HPs set to 10K. That is puzzling.


I raised the bass level on my preamp (those rarely used tone controls do come in handy!), and got sufficient, if not ideal in quality, bass output. I was able to determine that the 2Wqs are indeed working and generating sound. I got similar results with multiple source components.


What this means is that, I think, the new amp is not putting out much bass. Hopefully this is a burn-in issue, but I will confirm with the amp’s builder today. Of course, this does not explain why the in-line filters offered so much more bass output than the M5-HPs set to 10k.


If I am wrong about the amp, I will give you a call, Johnny. Thanks for all the assistance. Ditto everyone else here.

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