# Are my mains filtered below 80Hz?



## Misfit (Dec 27, 2013)

I didn't know where to put this, since technically it's a 6 channel receiver, but I'm only using 2 (okay, three) channels, with two "mains" bookshelf speakers. 

The amp is a Kenwood VR-7070, and I'm only using it as a power amp for my computer. 

CH 1: Main Left - Left Bookshelf speaker JBL NorthRidge N26 II
CH 2: Main Right - Right Bookshelf speaker JBL NorthRidge N26 II
CH 3: Subwoofer - (2) 4Ω JL Audio 10" wired in series

My source (computer) is just analog RCA cables into "CD" audio input - I'm not using the six-channel-surround inputs, but it still automatically crossed over the subwoofer speaker output. 

This Kenwood VR-7070 just automatically crossed-over the subwoofer speaker output, at whatever frequency it deemed appropriate. I'm just wondering if it also took it upon itself to cross-over my "mains" speakers to match. 

Does anybody know if I have to do something in a menu, or is it automatic, or does it not filter the mains speakers at all? I have the manual (PDF), but can't find this vital information. Thanks!


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## lcaillo (May 2, 2006)

Is there no info about the filtering in the manual or is it that you don't understand it? If the latter, post the pdf and someone might be able to interpret it for you. Sometimes manuals can be rather obtuse.


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## Misfit (Dec 27, 2013)

I don't know how to post a .pdf file here, but here's where I found it on Kenwood's site: Kenwood VR-7070 manual.pdf

The closest thing I could find for information regarding filtering is, "DTS (Digital Theater System) is a 5.1 channel digital audio format that provides five full spectrum channels and one low-frequency (subwoofer) channel for unprecedented clarity, optimum channel separation and a (wide) dynamic range." but I thought I was working with 6 channels here (only using three).

That says "full spectrum" so it would imply the bookshelf speakers are NOT filtered below 80Hz. 

But it _sounds_ like it filters out the low frequencies when I select the front speakers to be, "NML/THX" as opposed to "LARGE", which makes sense to me. I just can't find any text in the manual addressing any X-over frequencies anywhere. I suspect that's why it's a "consumer" audio product? Because "consumers" shouldn't bother with such details, and are supposed to buy all Kenwood branded THX matching transducers.

I'm not going to sweat it. It sounds great. I can't afford to "color-match" all my drivers, and I'll make do with how it is. I just get a little O.C.D. about these things.


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## fmw (Aug 11, 2013)

We still need to know how the sub is connected. Is it connected to the speaker terminals or to a dedicated subwoofer output port?


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## Misfit (Dec 27, 2013)

fmw said:


> We still need to know how the sub is connected. Is it connected to the speaker terminals or to a dedicated subwoofer output port?


Speaker Terminals. Dedicated, filtered (low-pass) powered subwoofer speaker terminals. 

Two enclosures, 4Ω's each. They are wired in series and powered from the Kenwood VR-7070's "dedicated subwoofer _Speaker Output_ (powered)". This Kenwood VR-7070's dedicated amplification channel sees this 8Ω load and pumps 100 watts RMS of _filtered_ subwoofer signal to the subs. (A low-pass filter is _automatically_ applied to this signal, sending only low frequencies to the subs.)

I am not using the pre-out subwoofer output (line-level), because I'm using the receiver's amp to power my passive subwoofer cabinets. Thanks.


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## fmw (Aug 11, 2013)

Page 21 has the answer. If you set the main speakers to Large then you will get no sub output. If you set them to THX you will get subwoofer crossed over at 80hz. That would provide the filtering you asked about. In stereo mode you get no subwoofer again. So yes. The only way to use your subwoofers as you have them setup is to set the main speakers to THX. That will send content above 80hz to them and content below 80 hz to the sub. Newer AVR's have way of adding subwoofer to speakers that are set to large but I can't find anyway to do that with your unit so I assume you can't do it.


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## Misfit (Dec 27, 2013)

fmw said:


> Page 21 has the answer. If you set the main speakers to Large then you will get no sub output. If you set them to THX you will get subwoofer crossed over at 80hz. That would provide the filtering you asked about. In stereo mode you get no subwoofer again. So yes. The only way to use your subwoofers as you have them setup is to set the main speakers to THX. That will send content above 80hz to them and content below 80 hz to the sub. Newer AVR's have way of adding subwoofer to speakers that are set to large but I can't find anyway to do that with your unit so I assume you can't do it.


Thanks. I scoured page 21 and its adjoining brethren searching for that specification, but could not find "80Hz" anywhere. Is that the "THX Standard" or something? I believe you're correct, as it sounds exactly like that, and its clarity and clean amplification has been seriously amazing me. 

It just "automatically" crossed over my subwoofer when I hooked them up to the subwoofer channel's speaker terminals. I was shocked and extremely happy. I set my fronts to "THX/SMALL" and everything was perfect. I did set my fronts to "-10dB" and my sub to "+10dB", because I'm not into balanced sound :unbelievable: I might like a heavy low-end emphasis in my music and my tops are more efficient than my bottoms. 

I've never invested much in a receiver before, only having "micro-systems" and cheap vintage old receivers, and once I bought the cheapest two-channel (like 50 watts max per ch) receiver when I was younger. I just mean, I guess I'm so excited, because I didn't even know it got this good. 

I only got this as a "hand-me-down" and I realize it's older technology and not worth much now, but I can't imagine anything better.


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## fmw (Aug 11, 2013)

Misfit said:


> Thanks. I scoured page 21 and its adjoining brethren searching for that specification, but could not find "80Hz" anywhere. Is that the "THX Standard" or something? I believe you're correct, as it sounds exactly like that, and its clarity and clean amplification has been seriously amazing me.
> 
> It just "automatically" crossed over my subwoofer when I hooked them up to the subwoofer channel's speaker terminals. I was shocked and extremely happy. I set my fronts to "THX/SMALL" and everything was perfect. I did set my fronts to "-10dB" and my sub to "+10dB", because I'm not into balanced sound :unbelievable: I might like a heavy low-end emphasis in my music and my tops are more efficient than my bottoms.
> 
> ...


80hz is a default. It is the best crossover point for most home theaters. Apparently there isn't as much adjustability as we have with newer AVRs. Good listening.


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## nova (Apr 30, 2006)

I was trying to find out the fixed crossover settings of a few receivers years ago. From what I remember most of them, like my VR-507, were set at 100 Hz. Your VR-7070 with THX certification will most likely have a fixed crossover setpoint of 80 Hz which is a THX Select and THX Ultra2 standard.


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