# What am I Missing with my V125?



## srckkmack (Feb 10, 2007)

I've had a M&K V125 sub for about 10 years. It's a 12" sealed sub with a 125W amp. I've been pretty satisfied with it for watching movies and listening to music (aside from likely room problems, but that's another subject). Our room is about 20x20 with vaulted ceiling and open to our kitchen. I was at the place where I purchased it lately, and a salesman told me that the sub is good, but underpowered for today's movies and music. I see many subs touting 350W to 500W, which greatly overshadow my meek 125W and start to wonder what I may be missing. Does anyone have an opinion they'd care to share about this?


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## Sonnie (Apr 11, 2006)

Hi Steve and welcome to the Shack!

Probably the best way for you to see what you are missing is to measure the response of you subwoofer from you main listening position. You may want to check out REW (Room EQ Wizard), available for download here at the Shack. I think you'll find that on your sub the response rolls off rather rapidly below 30Hz, which would indeed indicate that you are missing a good bit of information on quite a few movies.


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## Otto (May 18, 2006)

Hi Steve,

I recently sold an M&K MX-90, which is a dual 12" sub with a (I think) 125 W internal amp. I had a quick look at the V125, and I seems to be a newer, smarter sub than mine. I believe the V125 has only one 12" driver. I didn't look at the specs.

I'm in a similar situation as yours -- a largish, vaulted-ceiling room that's open to adjoining areas in the house: basically a lot of volume for a sub to fill. In the past, I was using Definitive Technology BP2002TL mains, and those also had one 12" driver in each. I generally ran those as part of the L/R material, and not as subwoofers.

So I finally got tired of the M&K. Or should I say that I got more excited about building an IB? Either way, that's what I did. Cut a hole in my floor and put four 18" drivers in there. I'm using the cheap MJ-18 drivers, but they work pretty well in this application. Depending on how I EQ things, I can get close to flat down to 10Hz.

So, to answer your question -- what was lacking in the stand-alone sub? First, as Sonnie indicated, low-end extension. I think I measured my M&K down to about 30Hz. Maybe 20Hz if I was generous, but it didn't really have much output in that area, when trying to fill that big room. Second, overall output. It sounds like you may be happy with the volume levels that you can currently achieve, but I never was. I don't watch movies at reference level much (ever?), but I can watch them at a reasonable level from time to time. I want to be able to reproduce what's on the DVD or CD when it's there. Third is headroom. I'd bottomed my M&K from time to time, but I don't have that with the IB sub. There's also a different "feel" to the IB than a box sub, but that's not really the question.

Sonnie also has a good suggestion in recommending you grab a RS meter and measure with REW. I found that equalizing with the BFD really changes things in the low end. If you're generally happy with the level of output from your sub, you may be able to improve the "type" of bass using EQ.

A couple questions for you -- have you played with placement of the sub at all? What's your crossover point? What's the rest of your system look like, especially your main speaker?

Good luck. Hope that helps a little, as I've been in a similar situation.


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## srckkmack (Feb 10, 2007)

Sonnie,
Thanks and glad to be here. I checked out REW and it looks extremely useful (and cool!). Last year I bought a RS SPL meter, but then didn't use it so I returned it. Looks like I'll buy one again, but likely the digital one this time.

Otto,
Flat to 10!!! Wooohooo! How often do you have to pound the nails back into the walls to hold up the drywall? Please don't mind my ignorance, but what's an IB? From my reading, it looks like I'll be investing in a RS meter and running the REW. Probably then get a BFD.

I have tried a few placements. This is our great room, so I'm somewhat limited in where to place it. My wife is pretty patient, but I don't think she'll go for the sub in a walkway or in front of the fireplace. Anyway, It used to be placed in the front right corner about 20 inches from both walls. Then I tried placing it further into the room away from the back wall but still about 20 inches away from the side wall. With this side wall placement I did not seem to get as much bass as with in the corner. Now I've got the sub back in the corner, but skewed a little so that the walls of the sub are not square with the room's walls (thought I read somewhere that this is good). These placements were done just by ear and memory, but I think having the meter will allow a better decision to be made.

Cross-over is at 80Hz, but I've set my fronts and rears currently to large. I actually just recently changed the speakers to large. I had them at small for over a year, but changed them to large after a recent auto-recalibration. I have Paradigm Studio 60's in front, 20's as surrounds, CC-470 center, Yamaha RX-V2400 receiver, and use the pre-outs to an Outlaw Audio 755 5x200W amp.

Getting back to my original question. I guess what do the frequencies below 25~30Hz do for you? Can you hear them? Do they just rattle the walls more? Or is it a "feel" thing?


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## bobgpsr (Apr 20, 2006)

srckkmack said:


> I guess what do the frequencies below 25~30Hz do for you? Can you hear them? Do they just rattle the walls more? Or is it a "feel" thing?


Really more of a (really cool :jump: ) feel thing. The cannons in Master & Commander or the deep (dropping ring) thumps in Lord of the Rings just are not the same without below 30 Hz subwoofer response. :dizzy:


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## Otto (May 18, 2006)

srckkmack said:


> Flat to 10!!! Wooohooo! How often do you have to pound the nails back into the walls to hold up the drywall?


Well, I went back to my thread where I've posted my FR plots, and I'll say it's "flattish" till 10. It's a little bumpy, but it gets the job done. How I wish the BFD could operate below 20Hz! And for the drywall -- there is a crack in the doorway, but it looks like it's been repaired before I moved here, so I'm thinking it's normal movement. But the sub can get _scary_. I have never turned it all the way up, and probably never will. If I had it to do over again, I might go with a little less...



> Please don't mind my ignorance, but what's an IB?


Ooops, sorry. IB stands for "infiinte baffle". It's a sub design that basically does not use a traditional box. In this case, the box size is "infinite". Many people cut holes either in their floor or ceiling, and then mount the drivers in the crawlspace or attic using a manifold or array. Here's a link to mine, which uses the manifold design. For starters, just browse through the pictures to get the basic idea... I really like it. Cheap, interesting, lots of bass, not "boxy" (whatever that means...).



> From my reading, it looks like I'll be investing in a RS meter and running the REW. Probably then get a BFD.


Depending on how much you are "into it", you might want to look at the Behringer mic (something like EMC8000). They can be fully calibrated (well, anything can, I guess) and they are probably more accurate over the full frequency range. There's also another SPL meter that I saw Sonnie talking about that does not require a cal file. If you like tinkering with this stuff, I'd go that little bit extra (I think it's something like $100 vs $40-50)



> I have tried a few placements. This is our great room, so I'm somewhat limited in where to place it. My wife is pretty patient...


Yeah, that's how it goes for the vast masses of us that don't have a dedicated theater (which I'm totally OK with). Corner placement will generally get you a boost. Check it with REW and you'll really start to get a feel for what's going on. 




> ross-over is at 80Hz, but I've set my fronts and rears currently to large. I actually just recently changed the speakers to large. I had them at small for over a year, but changed them to large after a recent auto-recalibration. I have Paradigm Studio 60's in front, 20's as surrounds, CC-470 center, Yamaha RX-V2400 receiver, and use the pre-outs to an Outlaw Audio 755 5x200W amp.


Nice system. Sounds like you're doing the right thing in playing around with the crossover points. I've done it so many times, I can't remember where it's set at this time. I think I'm running "large" on the fronts and a 40 Hz crossover point.



> Getting back to my original question. I guess what do the frequencies below 25~30Hz do for you? Can you hear them? Do they just rattle the walls more? Or is it a "feel" thing?


Yeah, as bobgpsr posted, there's just quite a bit of information there to be enjoyed, especially with movies. Some of it can be very tactile, and definitely shake the room if you have the output. Audio from 20 to 30 Hz can definitely be heard (by me, at least), and there's some music in that range. Also, my mains are rated to 30Hz, and they are respectable in that regard. But they just don't have the oomph, even for music, and I find that the sub really adds a lot at that 40 Hz crossover point. 

That's it for now! Good night...


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## Revenoor (Oct 2, 2006)

srckkmack said:


> I've had a M&K V125 sub for about 10 years. It's a 12" sealed sub with a 125W amp. I've been pretty satisfied with it for watching movies and listening to music (aside from likely room problems, but that's another subject). Our room is about 20x20 with vaulted ceiling and open to our kitchen. I was at the place where I purchased it lately, and a salesman told me that the sub is good, but underpowered for today's movies and music. I see many subs touting 350W to 500W, which greatly overshadow my meek 125W and start to wonder what I may be missing. Does anyone have an opinion they'd care to share about this?


I have the exact same M&K purchased in about 96 or so. I had it in my basement theater (14x25x8) with Klipsch Chorus II's/Academys/Quartets/RS-7s being pushed by Onkyo M-504s (165 wpc rms). I always felt that I was missing 'something' but didn't know what. Oh, it was loud in general but had no feel. I just bought an SVS PB12-Plus/2 and SMS-1 parametric eq and plugged it in at the same front right corner that the M&K had lived in for years. :raped: Holy shee aat Batman what a difference! I now listen at -20 db or so to get WAY more tactile feeling that I did at reference level. I can not over state the difference this has made. Next step is to fab and install the absorbers and bass traps, just waiting on the fabric sample to arrive so the missus can choose the color scheme.


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## srckkmack (Feb 10, 2007)

Revenoor,
I can see what you're saying about the "feel" (especially 900W vs 125W). The V125 sub sounds good with music and videos, but I don't feel the bass pounding the chest. We installed an Alpine system (head unit, 5-channel amp, speakers, and sub) in the van a few years ago. There you can really feel the bass. I guess that's probably when I first noticed something different about the bass in the house, but couldn't put my finger on it.

Since you previously had the V125, how does the SVS compare in articulation? Did you listen to other subs prior to your purchase?


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## Revenoor (Oct 2, 2006)

I did not audition any subs (other than a 3 minute listen to a couple of Klipsch at the dealer). Due to several factors I had limited my pick to either a DD-12, 2 of the HSU VTF-3 MK 3s or the SVS. The cost of each choice was the same, $1400 delivered. Velodyne did not answer any of my emailed questions, HSU basically replyed with this is what I pick for you and gave no justification for the choice, SVS folks spent the better part of 2 days swapping emails asking relevent questions (room size and layout, SPL readings at listening position, etc etc). I really didn't want to attempt locating the 2 HSUs and I guess the bottom line was that I liked the personalized attention that I got from SVS. I really have not gotten a chance to optimize the location and eq of the setup and have decided to delay the tweaking until I get the room treatments up. My dear wife lost about 75% of her hearing and doesn't get to appreciate music as it should be but I will say that since the SVS went in she is going thru the DVD collection at an alarming rate and gets lost in the action now that she gets to feel the sound. The down side is that I have had to go around ensuring picture, knick-knacks, etc are not about to bounce off shelves two floors up. This is not a booming, un-clear trunk rattling car next to you at a red light. THIS is a sharp, start now - end now bass note that could if so desired leave you breathless. The closest I can relate is some bars in the Phillipines that had complete walls of woofers that would actually change your heart rate if you stayed long enough but now its CLEAN.


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