Not enough Power ? [Archive] - Audio & Video Forums


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02-12-2004, 07:45 AM
I just picked up a few goodies last night.

HK - AVR130
pair of Polk RTi70's

I already had a 10" KLH Sub.

I've heard lots of people say not to use the subout on receivers, so I didn't.....but when I wire everything up to run wire from the amp to the sub then to the RTi's. Everything loses bass it seems., SUBSTANTIAL BASS.

I usually keep my sub on about 25% but I had to turn it up all the way to get probably half the same output.

The Polks can handle 50-250 watts

The HK puts out 50 watts X 2 and 40 X 5.
Am I under powering them? Should I just use the Sub preout? AND does anybody know if the HK-AVR130's subout is a TRUE preout? or is it filtered?

THank you so much, anyone who answers


02-12-2004, 11:35 AM
Chris, its really up to you. I use the subwoofer preout on my HK AVR-320 and it sounds great. Of course it depends on your sub. You must have a line level input on your sub to use it (most subs have this). If you use the subout then you will have to go into the receiver setup menu (OSD) and first choose the types of speakers you have (large or small). I think your recevier has triple crossover bass control. You need to read that manual and errata sheet to set this up properly. If you set it up wrong you may have huge holes in the frequency range. So you gotta set the speakers up, set the crossover settings, and finally choose sub, lfe, or lfe + l/r. If your not familiar with setting up receivers you may have to read that manual numerous times and even email tech support at HK. HK receivers are fairly difficult to setup (lots of options) but well worth it in the end. Good luck. Paul.

02-12-2004, 03:37 PM
Excuse my ignorance, but why would you not want to use the sub pre out??

This Guy
02-12-2004, 03:44 PM
the other option to using the sub pre-out, is by having your mains set to large, and have the left and right speaker outputs go through the subs crossover, then to the speakers. This lets you choose whatever frequency you want to crossover at, where as the receiver may be fixed at one frequency (80 hertz) or may have a couple frequencies to choose from. This will let you better match your sub with your main speakers.


02-12-2004, 06:13 PM
Your receiver should have plenty of power to handle the speakers you got. My question would be why anyone would tell you not to use the sub output. It makes sense if your subwoofer is a passive model with no amplifier on board. If it has an amp, then you got two approaches to hooking it up.

First, easiest way is to use the low pass sub output from your receiver, set your speakers to "Small" and let the receiver handle the bass management. This is what you should do if you plan to mostly handle home theatre sources. With the receiver handling the crossover, the subwoofer's crossover is no longer needed, so you should turn the crossover frequency on your subwoofer all the way up (or bypass it, if possible).

The second option is to high pass the speaker by running the speaker cable from the receiver to the sub and then over to the speakers, which you've already done. This means that you have more control over the crossover frequency, but it's also more trial and error in blending the main speakers with the subwoofer. The key to making this work is to correctly set the crossover frequency and the level correctly.

The position of the volume has NOTHING to do with the actual power output, because the low level RCA input and the high pass speaker inputs feed the signal to the subwoofer differently, so the preamp gain level will not necessarily be the same.

What you really need to do is use the tone generator in your receiver and make sure that the level of the speakers is the same as the subwoofer. If you can't get the subwoofer level to match, see if your receiver has a setting that cuts the mains (my receiver can cut the mains by 10 db). The best thing to do is get a SPL meter and a test disc, and set the levels that way.

02-13-2004, 07:06 AM
I've heard lots of people say not to use the subout on receivers, so I didn't.....but when I wire everything up to run wire from the amp to the sub then to the RTi's. Everything loses bass it seems., SUBSTANTIAL BASS.

I think what happened was that you forgot to set the main as Large with this connection. If you set them as Small the bass is cut out from the main channel by the receiver at the selected receiver crossover freq.