Need HT Speaker Guidance - Axiom, Ascend Acoustics, Rocket, Swan, Paradigm, Aperion! (1 Viewer)

[Jonny K]

Ok, an update. I've been playing with the BFD and tweaking my settings for several days. This is what I ended up with:



The blue line is the response curve before the BFD is used, the pink line is the new curve. You'll notice that around 70 Hz the volumes increase. There is nothing I can do about this, it's my main speakers playing those notes (my Yamaha receiver has a fixed crossover I can't change, and even though it's supposed to be 90 Hz it clearly goes lower than that). To compensate for the high volumes from the main speakers I attempted to raise the sub volume. It's now as high as it goes on the sub, so that's as good as it will get. (the signal from the receiver is reduced significantly, but that's to avoid clipping in the BFD). One interesting thing I noticed is that the dip at 125 Hz would become extremely large for some settings I used (combinations of phase, crossover (on the sub), and BFD filters). I didn't expect to modify such high frequencies!

Overall, a good result. Movies definately sound different now, less boomy. I ended up using 6 filters before I got tired of messing with it.


As for the cable filter, I actually asked a cable guy when he was over at my place installing high speed internet. He basically told me there was nothing he could do. After he left I inspected the cable ground. It was connected to the same pipe that the main electrical ground was, although it was in a different spot. I went and moved the cable grounding wire so that it was attached to the pipe at the same spot the main electrical ground was. I found this reduced the hum (the main speakers no longer pick up on it), but the subwoofer still hums like crazy. Aw drat. The problem with buying that cable filter from Parts Express is that it's 10 dollars US for the filter, and 10 dollars US for the shipping. I'll end up spending 30 Canadian dollars for a tiny little part! I wish I could find it locally. And I don't want the Jensen part because that's even more money (it seems silly to me to spend 100 Canadian dollars on a tiny cable filter when I don't even have HDTV or watch much TV in genearal).


Jonny K

 

[mackie]

Looks pretty good. Try unhooking your mains and just running the sub for your measurements. That may help you dial in in some. Does your sub have a cross-over filter on it? You can always use that instead of the receiver's if it gives you more options.

Without the BFD, I have a huge hump at 40hz too. Taking that out really changes the character of my bass.

 

[MikeNg]

You can play with the phase a little to see if you get any beneficial cancellation in that 70+ region.

 

[Jonny K]

See the dip at 125Hz? When the phase is set to anything but the current value that dip increases dramatically. It'll go down to 60 dB. I tuned the phase to maximize the volume at this frequency and get rid of the dip as much as possible.


Jonny K

 

[mackie]

You got me on the hump at 100hz. Did you try putting a filter in at that frequency? With a crossover set at 90hz, the sub frequencies should start going down in db. I'm not sure of the cross-over slope of the Yamaha though and what the output to the sub will be at that frequency. I doubt it's down much at 100hz.

Which Yamaha receiver are you using?

How close are your main speakers to a wall?

Where is the sub? Have you tried moving it around the room?

If the speakers and the room are the culprit you'll need to look at set-up and room treatments to bring that down.

Not trying to needle you with questions - just brainstorming different possible solutions.

 

[Jonny K]

Yes, I tried filtering at 80hz, 90hz, 100hz, etc. I even tried extremely aggressive filters (-40db) with no effect at all. It's all main speakers at that point...yet somehow the sub is effecting those freaquencies still. The receiver is a Yamaha RXV-1300, with a crossover point of 90Hz according to the manual. The speakers are away from the side walls by maybe a foot or two. The sub is in the only place in the room where I can put it, between the left speaker and the TV. I suspect the room has issues, but I don't know. Additionally, switching the sub amp from Full Range to Crossover mode and tweaking it had significant and unexpected results on response. It was a huge pain to tweak!

Here is a picture of the setup. Note that the left and right speakers are no longer toed in to such an extent:

http://members.shaw.ca/jonnydk/misc/IMG_1483.JPG


Jonny K

 

[mackie]

Holy crap that's a big sub!

From the pictures I can see a couple of potential problems. Your speakers are basically in large cubby holes which will emphasize the bass. They're fairly close to side and rear walls with a large entertainment center in between. Is there any way to get a smaller stand for the TV and components and move the speakers farther away from the walls?

I strongly suspect that's where a lot of the problem lies. If you did this, you'd probably also have a dramatic improvement with imaging, and the sound stage depth and width would increase.

You might also try plugging the ports on the speakers to see if that helps. It sounds like a crazy idea but it will cut bass output. It's worth a shot.

 

[Jonny K]

Yeah, that giant entertainment unit definately limits placement. But I have no choice, it's got to stay. Many men nearly died getting it in our house (it weights a lot), and mom declares it will be sold with the house.

As for the sub, that's my DIY Adire Audio Tempest sub. Yes, it's huge. There's no replacement for displacement! Unfortunately it also weights a massive amount too (built out of compressed particle board).


Jonny K.

 

[mackie]

We all have to make compromises when it comes to interior design and HT:frowning:

Keep trying different placements and bring the speaker out into the room more. If the 100hz peak is too bothersome, there are speakers that have boundary compensation setting built into them that can help. A lot of your professional studio monitors have them. I believe NHT's M5 & M6 speakers have this and some from Atlantic technology. There are others but it's escaping me now.

If the peak isn't too bad, sit back and enjoy and realize nobody's system or room is perfect. If you were in another room with a different set-up you simply have different trade-offs.

 

[Jonny K]

Considering I just bought a new set of speakers, I don't think I'll be upgrading again any time soon. I can't complain about that peak. I equalized the bass and that's what I intended to do. If I start worrying about a 100hz peak I might as well do a full equalization of the entire frequency spectrum and worry about all the peaks.


Jonny K