AR.com kit and Sonotube Sub?

[dustobub]

I will be building five AR.com speakers from madisound in the next few weeks for 50/50 Music/HT use. I was a little curious how well these speakers work as a center channel speaker. Would going with another speaker with a MTM design be a better choice? My room is far from ideal at about 12x14, with two open walls. It's kind of hard to picture, but it is the best I can do in my small apartment.

I have decided to build a sonotube sub after reading a lot about them online. Would a sealed sonotube with either a 15" Quatro or 15" Atlas be a bad match for the AR.com speakers? Also, as I don't want to install a plate amp on the tube, could someone recommend an inexpensive external amp that would be well matched for these drivers. Any other recommendations are also welcome. Thanks.

Dustin

[Geoffcin]

I will be building five AR.com speakers from madisound in the next few weeks for 50/50 Music/HT use. I was a little curious how well these speakers work as a center channel speaker. Would going with another speaker with a MTM design be a better choice? My room is far from ideal at about 12x14, with two open walls. It's kind of hard to picture, but it is the best I can do in my small apartment.

I have decided to build a sonotube sub after reading a lot about them online. Would a sealed sonotube with either a 15" Quatro or 15" Atlas be a bad match for the AR.com speakers? Also, as I don't want to install a plate amp on the tube, could someone recommend an inexpensive external amp that would be well matched for these drivers. Any other recommendations are also welcome. Thanks.

Dustin

A 15" sub in a room that size is great for LFE, but really bad for fellow apt dwellers. I can guarenttee heated arguments with neighbors after installation.

[kexodusc]

I have a 15" Quatro with the ar.com designs in my home theater rig right now...currently experimenting with some mods to the ar.com's to fine tune them to my needs but this is a good combo for sound quality.
The 15" Quatro delivers an incredible value...I've heard some $400 woofers that don't sound any better unless pushed to the limits. The Quatro was made to be the best sounding driver it could be without a need to play at an average SPL above 105 dB or so...that doesn't mean it won't hit 110-115dB's at peak for explosions, etc, just that for music it's comfortable playing at or below 100 dB's. Most 15" woofers today concentrate on attractive output numbers - it's turned into a horsepower race. And you rarely see great sounding woofers that don't also have a lot invested into high output capability - IMO this just drives the cost up without effectively allocating resources to the performance area many people are most concerned with -sound. It's about time someone recognized a need for sound quality without the need to get arrested for disturbing the peace. It's low xmax design really lends itself to sounding musical. In your small room it's an excellent choice since you won't need the high SPL capability.

Geoffcin's right though - it's physically big and will still play louder than many 12" woofers...make sure it's not overkill for you.

The Ar.com works fine as a center channel, and for several reasons is far better than your typical midwoofer-tweeter-midwoofer center channel speaker. In my large room though I actually preferred the wider soundstage and after awhile decided to go with a typical center channel...If you don't want to build one yourself (the crossover is not as easy as doubling and halving inductors and capacitors and removing the resistors to unpad the tweeter) you can contact Ed Frias who sells a voice matched center channel for under $170 or so as I recall.

The Ar.com's aren't shielded...depending on your setup and TV you might actually be better off with Ed's speaker.

[dustobub]

I have heard nothing but good things about the Quatro, however, I am a bit worried about sag since I will be using it in a downfiring config (sonotube). I have read that the sag for the Quatro is over 5% which is the max recommended sag for downfiring subs. Should I just say whatever and use the Quatro or should I look at a different sub such as the Atlas? I don't know what the rated sag for the Atlas is, but I will email Ascendant Audio.

I will be using a 24" diameter sealed sonotube to keep the the length as short as possible. Are there any tools available to calculate length for sonotubes, Winisd only does boxes. Should I just follow the recommended volume for a sealed box and apply it to the sonotube, or are there special calculations I must do? Thanks

Dustin

[Dick Hertz]

If you don't want to mount the sub amp on the tube (since the amp's mount is flat and the tube's round) why not use a separate box for the sub amp and connect to the sub with regular ol' speaker wire? You need a crossover to integrate the sub with the rest of the speakers and there's one built into most subwoofer amps. If you use a separate two-channel or mono amp you'll have to get an active crossover too, so why go to the added expense? One other consideration. Since the crossover to the satellites is usually 12dB on the sub amp, you'll get a better blend if you plug the port on the AR's. A pair of old dirty gym socks will be ok.

[kexodusc]

The Quatro's recommended plate amp is a 240 watt jobber from Parts Express with a 24 dB/octave crossover...I've never heard a sub disappear with my speakers better than this 15" unit...big as it may be, my room is quite fussy and the 24 dB slope helps. Using the receiver's cutoff makes it even easier if the option exists...

[Geoffcin]

The Quatro's recommended plate amp is a 240 watt jobber from Parts Express with a 24 dB/octave crossover...I've never heard a sub disappear with my speakers better than this 15" unit...big as it may be, my room is quite fussy and the 24 dB slope helps. Using the receiver's cutoff makes it even easier if the option exists...

I distinctly remember you thinking that smaller subs were more musical....has the big 15" changed your mind? I know when I went from a 12" to a 15" it was a real "eye opener"

[kexodusc]

I distinctly remember you thinking that smaller subs were more musical....has the big 15" changed your mind? I know when I went from a 12" to a 15" it was a real "eye opener"

Not exactly. :D

I don't remember a particular conversation with you in particular, but I do recall voicing observations of several subs I've owned, often between the PW-2100 and PW-2200 or VTF-2 and VTF-3 models. So any statements I made should be taken in context.

I'm not a big fan of your typical 12" ported subs for music. I find the equivalent 10" subs to sound much more "musical". They often have a significantly lower compliance than larger ported subs, often a smaller xmax, and greater control. They also have less power handling and would sound horrible if used in too small an environment. If I had to make a generalized statement (which apparently I did in the past), than yeah, smaller woofers are better in ported cabinets. Sometimes the difference is quite noticeable, sometimes it's very minor...I believe it's usually there. But there's also a tradeoff where a smaller woofer won't sound good if driven too hard, in which case a larger woofer is better.
Having said all this I honestly believe that two 10" ported subs would be more musical than one 12" sub, without question...not even considering the added output or benefits of 2 subs. Problem with recommending 2 10" subs is the price in most cases.

Sealed cabinets are a whole other animal. The sealed box add a stiffening element to the oscillation to a point where the difference between 10" and 18" woofers even is much smaller, the increased "musical benefit" is less, but I suspect still present. This all relates again to the reasons why I also think sealed subs are more musical than porteds. This difference is much greater and more substantial than the difference between woofer sizes. Problem with sealed cabinets is driver excursion, power handling, and low response...you almost always NEED a larger woofer than a ported sub to get good results.

That doesn't mean some larger more expensive woofers don't sound better than smaller woofers...obviously a $400 15" woofer would be expected to sound more musical than a $40 10" woofer.

If you really want to take me to task on some of my comments from back when, look up some of the things I said about ported subs not sounding much differen than sealed subs...(I'll blame this on poor models and ignorance in my youth). Or, after failing twice to notice the benefits of "stereo subs", I'm pretty darn close to trying that experiment one more time...I'll let ya know.

Having 5 months off in the last year and a half has really allowed me to study up on stuff I like in this hobby...I've read more books in this time than I've leisurely read since high-school!!! I've learned more in the last year than my everthing I learned in the 11 years I've considered myself an audiophile. The only discouraging part is I now realize better than ever how much more I have to learn...

P.S.
I'll tell ya one thing...ya just can't substitute the "cool factor" a 15" woofer has when it's thumping away! :D

[Geoffcin]

Not exactly. :D

I don't remember a particular conversation with you in particular, but I do recall voicing observations of several subs I've owned, often between the PW-2100 and PW-2200 or VTF-2 and VTF-3 models. So any statements I made should be taken in context.

I'm not a big fan of your typical 12" ported subs for music. I find the equivalent 10" subs to sound much more "musical". They often have a significantly lower compliance than larger ported subs, often a smaller xmax, and greater control. They also have less power handling and would sound horrible if used in too small an environment. If I had to make a generalized statement (which apparently I did in the past), than yeah, smaller woofers are better in ported cabinets. Sometimes the difference is quite noticeable, sometimes it's very minor...I believe it's usually there. But there's also a tradeoff where a smaller woofer won't sound good if driven too hard, in which case a larger woofer is better.
Having said all this I honestly believe that two 10" ported subs would be more musical than one 12" sub, without question...not even considering the added output or benefits of 2 subs. Problem with recommending 2 10" subs is the price in most cases.

Sealed cabinets are a whole other animal. The sealed box add a stiffening element to the oscillation to a point where the difference between 10" and 18" woofers even is much smaller, the increased "musical benefit" is less, but I suspect still present. This all relates again to the reasons why I also think sealed subs are more musical than porteds. This difference is much greater and more substantial than the difference between woofer sizes. Problem with sealed cabinets is driver excursion, power handling, and low response...you almost always NEED a larger woofer than a ported sub to get good results.

That doesn't mean some larger more expensive woofers don't sound better than smaller woofers...obviously a $400 15" woofer would be expected to sound more musical than a $40 10" woofer.

If you really want to take me to task on some of my comments from back when, look up some of the things I said about ported subs not sounding much differen than sealed subs...(I'll blame this on poor models and ignorance in my youth). Or, after failing twice to notice the benefits of "stereo subs", I'm pretty darn close to trying that experiment one more time...I'll let ya know.

Having 5 months off in the last year and a half has really allowed me to study up on stuff I like in this hobby...I've read more books in this time than I've leisurely read since high-school!!! I've learned more in the last year than my everthing I learned in the 11 years I've considered myself an audiophile. The only discouraging part is I now realize better than ever how much more I have to learn...

P.S.
I'll tell ya one thing...ya just can't substitute the "cool factor" a 15" woofer has when it's thumping away! :D

There's a big difference between a "one note" bass sub, and one that can articulate notes musically. It's funny though how we, after years of experimenting, wind up with very similar conclusions.

[kexodusc]

I also find it remarkable at how far subwoofers have come in terms of both value and performance in just the last 5 years alone. IMO, this is one are that's really benefited from the home theater boom (no pun intended)...the progress rivals that of the ever-changing digital advancements...

[Geoffcin]

I also find it remarkable at how far subwoofers have come in terms of both value and performance in just the last 5 years alone. IMO, this is one are that's really benefited from the home theater boom (no pun intended)...the progress rivals that of the ever-changing digital advancements...

Back when I bought my subs (2000) There were VERY few choices besides Velodyne that made sense. Now the story is a lot different, SVS, HSU, and a host of companies make great subs. The bar is moving ever higher.

[dustobub]

Well I think I have decided to go with the Atlas because of the sag issue. The Atlas 15 only has a 2.8% sag compared to over 5% on the Quatro. Based off the recommendations on this (http://www.ascendantaudio.com/archive/Atlas%2015%20sealed%20enclosure%20recommendations. htm) page using the low QTS setting, 3.7ft^3 looks like it would be perfect for me. Now I assume I would just use a sonotube that gives me this volume. Using a 20inch diameter and a 22inch height gives me about 3.7ft^3 when you subtract the added volume from the 3/4inch mdf on the top and bottom. Do these numbers look correct? It's rather short and fat. Thanks.

Dustin