Av receiver with 40hz manual eq.

[jonone]

Im using an 2010 Yamaha av amp and I tend not to use the ypao, but only eq the sub with a minidsp.
Problem is I have a huge room mode at 40hz which is present in the speakers so I would like to manually eq this and not effect the rest, my Yamaha manual eq only goes to 62hz, so do any brands or later models offer manual eq to 40hz or lower?

Thanks.

 

[jonone]

I've been looking at some Yamaha aventage manuals and the a820 says you can manual eq from 31hz, but does that only apply to the sub channel? or does the 31 hz and up eq effect the mains as well?
Thanks

 

[PSM1]

Have you tried setting your speakers to small with a crossover greater than the 40Hz node? This would mean you could eq the sub and then not worry about the other speakers. The general advice for a 5.1 system is to set all the speakers to small and a crossover of 80Hz.

 

[jonone]

Hi, yes I'm going to use a 60hz crossover, I'm planning on a nearfield sub so I want to keep the crossover low.
The 60hz xo helps but the mode is still present, I would like to be able to eq it out before I eq the sub seperatly.
Thanks

 

[dante01]

Not much attention is payed to the lower frequencies asspciated with the main channels because such frequencies are more commonly redirect to the sub or included as part of the LFE channel which is destined for the sub. EQ room correction seldom wastes processing power filtering the lower frequencies associated with all channels and usually dedicates such attention to the LFE/sub pre out channel. Audyssey recommend you always use the SMALL speaker setting for this very reason. There's no benefit to first EQing the frequencies in association with the main speakers to then redirect those frequencies away to the sub to have them then EQ'd in relation to the sub's output. Responses would be different due to differences in location and room acoustics. If redirecting the frequencies then you need to EQ them wilth the response measured in relation to the speaker they will be output from, not via the response they give via speakers thet will eventually not output these frequencies. Adjusting the EQ as measured via output from the main speakers makes no sense if the frequencies are to be redirected to the sub. The EQ adjustments would not be valid or come into play.

 

[jonone]

Ok thanks for the detailed response, does this mean you cannot eq the mains at 40hz then? I agree I'm only looking at the response of the mains on there own, which may change when the sub is added as it depends on how they interact together.

 

[dante01]

You may be able to adjust one frequency band close to 40Hz, but I'd not expect to get much adjustment leeway at or below this with any AV receiver. Most EQ systems reserve the lower bandwidth adjustment to the sub pre out channel and even then don't really allow you finite manual adjustments in relation to to lower bandwidth curve used. The fact is that you'd need seriously expensive main speakers to realistically be able to hear or experience frequencies lower than 40Hz from them so EQing the lower frequency output wouldn't really make much sense anyway.

The main speakers shouldn't interact at all with the sub as far as the same frequencies are concerned. the crossover will allow some degree of roll off and overlap to prevent dramatic changes, but the sub should be setup to handle all the lower frequencies and you shouldn't have a set up that uses both the main speakers and the sub for these frequencies simultaneously. Such a setup more often than not results in undesirable bass boom.

 

[jonone]

Ok thanks again, I will see what happens when I try and integrate the sub.
As for overlapping the mains and sub, there is different schools of thought on this, some people like earl geddess and Wayne parham etc use there mains full range and there subs/ midbass modules are overlapping the same frequency's, this gives a dense interference and can be smoothed out by phase/delay adjusment resulting in a very flat fr. So you run 3-4 subs/mid bass and your mains giving you 5-6 bass sources. But I have to admit you should have fairly hefty mains, although mine are fine full range in my room at the levels I listen too.
The 60hz crossover is a compromise in my case.