An excess of bass

quadzilla

Probably not what most people complain about, but I hooked up a pair of M&K V-125s last night to replace the PSW 450s I've been running. The reason for the change is that the PSW 450s, while very nice subs, started to roll off a bit earlier that I wanted, and have a -3db lower limit of 35Hz. The M&K -3db is 20Hz for comparison (I'm thinking this will take movies to a whole new level). Now, however, I'm trying to get them integrated into the rest of the system, and I notice a bump in the lower frequencies. This is especially noticeable on something like Chili Pepper's albums. Before, Flea's bass line just lacked a bit of low-end punch, but was otherwise very smooth. Now, the low end actually seems almost boomy, despite the sealed enclosure. There's a definite increase in volume in the lower registers, even after running the calibration on the AVR several times. I have all speakers set small, and the crossover is at 80Hz. Anyone have any tips on getting the subs smoothly integrated again?

Ern Dog

I've had this happen before and what helped was to move my rig to the other side of the room which greatly reduced the boom. Room placement of subs is key. Another idea I haven't tried yet is adding some bass traps to help reduce the peeks and valleys in the lower frequencies. A third idea is to get a Velodyne sms-1 bass management system. These things are awesome and I love mine. It has helped to integrate my sub seemlessly with my speakers. Using the eq will reduce the boom and reveal the frequencies that all the boom is masking. You can get them used for $300.

quadzilla

Hi Ern,

So the Velodyne unit works with any subs? Cool, I didn't know that. I'd assumed it was part of a Velodyne set up. I'll definitely have to keep my eyes open for one.

Your point about placement is dead on. I did finally get this sounding very nice by moving the subs from the opposite corners where I had the PSW 450s to putting the V-125s along the middle of the side walls. The final step was to face them towards the front of the room, rather than facing them into the room. Bass is now very deep, and fairly tight with little to no boominess. I think I can get it tighter and level things out a bit more, but the difference between where it was Saturday when I first hooked everything up and where it is now is night and day.

I still want a pair of Micropro 4000s though.

thsmith

Quad, for now make sure your subs are balanced output to mains by using AVR test tone and RadioShack SPL meter.

Acoustic panals will help alot.

Another option to SMS-1 is to learn Room EQ Wizard (REW, free at hometheatershack.com) and use a $99 BFD 1124P to tame the peaks.

You will need a PC with sound card that has mic in.

You can't boast dips or shouldnt with SMS-1 or BFD.

REW and SMS-1 will help with placement to minimize dips but you need filters to cut the peaks.

quadzilla

Hi th,

I've got a feeler out to a guy here locally that makes panels. Hopefully, I'll hear something back from him. I'll look into the rest of what you mentioned.

How good does the mic and sound card need to be? I've got a laptop with an integrated SoundMax chipset and have a couple of cheap PC mics laying around. I might still have a couple of Shures floating around somewhere if that would improve the accuracy. Or I have a PC with an Audigy card. Of if there's something else that would work better, I can go grab that. Or maybe it doesn't make that much difference and I'm over-thinking this whole thing?

Thanks for the response.

thsmith

quadzilla wrote: »

Hi th,

I've got a feeler out to a guy here locally that makes panels. Hopefully, I'll hear something back from him. I'll look into the rest of what you mentioned.

How good does the mic and sound card need to be? I've got a laptop with an integrated SoundMax chipset and have a couple of cheap PC mics laying around. I might still have a couple of Shures floating around somewhere if that would improve the accuracy. Or I have a PC with an Audigy card. Of if there's something else that would work better, I can go grab that. Or maybe it doesn't make that much difference and I'm over-thinking this whole thing?

Thanks for the response.

Since you live in Richardson, I work in Richardson and live in Plano we should meet.

A friend of mine made bass traps and my wife makes the covers for the Owens Corning 705s that is pictured in my show case. The 705s can be bought locally at SPI for about $12 a piece. I do not use Bass traps but they would help me. My room is just not suited for them but the OC 705 panals help.

I use the Turtle Beach SRM SC. Since we are local I would be glad to give a REW Demo.

I know longer need the BFD since my SVS sub had 1 programable filter and luckly that is all I need but without REW I would not have been able to figure out how to set it.

thsmith

Here is a picture of my friends Bass traps. Behind the covers he cut and stacked triangle OC 705s in a frame. They work very well.

quadzilla

Hey, yeah, I'd love to see your set up. And you're more than welcome to see mine.

Dagoods

I could not think of it this morning when you asked me but Here's a link to where I got the idea from to make the one's posted. It shows them with the covers off and how they made the frames. I made mine just from looking at the pictures.

http://www.hometheatershack.com/forums/home-audio-acoustics/7758-corner-traps-finally-finished.html

thsmith

Dagoods wrote: »

I could not think of it this morning when you asked me but Here's a link to where I got the idea from to make the one's posted. It shows them with the covers off and how they made the frames. I made mine just from looking at the pictures.

http://www.hometheatershack.com/forums/home-audio-acoustics/7758-corner-traps-finally-finished.html

And a nice job it did taming those Outlaws:cool:

Kex

quadzilla wrote: »

... Now, however, I'm trying to get them integrated into the rest of the system, and I notice a bump in the lower frequencies. ... Now, the low end actually seems almost boomy, despite the sealed enclosure. ... I have all speakers set small, and the crossover is at 80Hz. Anyone have any tips on getting the subs smoothly integrated again?

Quadz, I am using a sealed enclosure sub too, and it blends absolutely seamlessly with my RT55 speakers. I have no problems with boomy bass, although I still think I might prefer a different solution for certain types of music, ideally, without having had the time to investigate this thoroughly as yet.

In any case, after I hooked up my current receiver, which is a fairly modest NAD, I noticed that I got a huge improvement in very tight, detailed bass. This prompted me to lower the crossover on my RT55 & CS400 setup all the way to 40Hz. The bass was much better (less boomy, more controlled), IMO, than at 60Hz, which I had preferred with my previous receiver, and even a pre + external amplifier setup. The RT55 are roughly equivalent to the RTi8, but you are using RTi12, so I would strongly suggest you play around with your crossover setting below 80Hz to see what you think. You may not get the same results, or like them as much, but it's worth a try IMO. You might even try leaving the speakers set to large and play around with that too, but ensuring that LFE is fed to the speakers and the subwoofer, not just the speakers. I haven't done much of this, and the options vary between brands, so I can't go into great detail about this.

Sometimes a different setting is preferable for music vs. home theater. Some receivers have direct access to certain channel levels from the remote, including the subwoofer, to adjust for this. Mine even allows me to memorize five different preset sytem adjustments, making it even easier to switch from HT to music listening. If you have this option, you might find you prefer to modify your settings according to what you are using the system for on any given occasion.