Need some audiogon expertise

Hi all, I am having a little problem here with thin bass. I am not really sure where to start. Some help would be most apprecieated. I have heard some say tubes in preamp but i dont feel that 2 little 6922's can be causing the music to be so thin but maybe so. Heres my list of equipment.

California Audio Labs Icon/Powerboss
Audible Illusions L-1/matched pair of 6H23-EB
Aragon 4004 mkII
Sansui TU-717
Vmps Tower 2/R's
Acoustic Research 12 guage
Radio Shack fusion IC's throughout

Stand alone i've not heard of any of the components having the traits of thin bass. But obviously i have something causing this.

Room is 22 x 14 x 8. Speakers are on the short wall placed 2 1/2 feet from back wall and 3 feet from sidewalls toed in directly at my listening position which is 10 feet from speakers.

Thanks for the help.
Cables and interconnects are the place to start.
Have you had this system long? The components have been around since about 1990. Did the system ever provide a fuller bass? You're right that it should sound good. There's enough power and the speakers are designed to provide you with solid bass. I'm wondering if the thin bass is a recent phenomenon? If it is, then here are my questions:
1) Did you change anything lately (e.g., cables or room)?
2) Is the problem present in both channels?
3) Has this been a gradual decline in bass response or sudden?
It is nothing less than absurd to blame "Cables and interconnects" for thin bass or grainy highs! Room-speaker interaction, Speaker position, Speakers and/or source, equipment synergy, would be place i would look first. Find yourself Stereophile Test 3 CD, and start from there.
Try a Peavey Kozmos processor. Go to the Peavey website. It will help for room corrections and cost only 250-300.
Celtic, in response to cables and interconnects. I have had radio shack ic's in other systems and never had a bass problem and i have always used 12 guage speaker cable so i am not sure if i can go along with that idea. Only because of my previous personal experiences with the same products.

Ozfly,this is a recent compilation of equipment gathered from reviews, chats, and what other users have had to say with each piece of equipment. All equipment is easily an 8/10 and some 9/10. Aragon is from 1993. Audible Illusions is from 1995. The Cal Icon is from 1990 but had been to factory in 1996 for powerboss upgrade and check up. Vmps or from 1993 and the sansui tuner is 1977.
In response to your questions,
1)System has been put together in last 6 months.Cables and ic's were purchased new.
2)Yes,both channels have the exact same trait.The highs are very smooth the midrange is slightly recessed (nature of the vmps).I can actually listen for hours and never be fatigued.In the midrange and highs its the best system i have ever had in my home.
3)Its just been thin from the first day i hooked it up.

Lindemman,as for equipment synergy everything sounds fantastic except for the thin bass. The difference i do have from other systems that i have owned is this one is on the short wall and my other systems were on the long wall. But i have heard so much talk about using the short wall with much better results that i have indeed set this fairly new system up that way.
Could it be possible that the room, with all these components that are considered to share in one common trait together,which is good bass, is the source of my problem?
I will try to find a test cd and i will also need to purchase a meter to test my frequencies, any recommendations?

Thanks all for you input.
I'm with Lindemman. It sounds like speaker positioning. Those VMPS are very capable in the bottom end. Might as well start there, it's free :-)
Not sure about the tower II's, but I have the super tower/r's which are the next model up. Make sure your speaker cables are in the lower set of inputs on the speakers and the switch is in the down position if they have this on them, The switch is for bi-amp and takes the place of jumpers most other speakers have. Also, as you bought these used, make sure the putty mass that comes pre installed on the passive is in place and of the correct amount (they come from factory fully damped/you remove putty in small amounts to tune the passive). These speakers should have great output at 30hz. and good output down to the mid 20's.
Celtic probably speaking of some magic cables that act sort-of like components giving large bass "extentions" right?
Other than that I guess your amp may need an upgrade.
Shop for Bryston 3b-st. It's affordable and has a nice deep bass.
Yoo've said you had this system 6 months. This is just a thought, but perhaps previous systems have accustomed you to more boomy bass and what you're hearing now is just more accurate?
I agree with playing with speaker positioning first. Closer to the walls should get more bass (tighter?). Keep in mind that this is a very "mellow" system. Quite nice, clean and detailed, but won't have a lot of bite.

As far as the tubes for future reference: 6922s should last 5000 to 10,000 hours. Big reason why manufacturers love them. Changing tubes will make a huge difference. Let us know what kind you have now and someone should make a good suggestion (don't say sovtek, please...). When the tubes start to go, everything will get muddy sounding when you push them hard and the whole system will lack power. They are easy to check and I'm sure you can find someone near you with a tester.
Creeper and Sogood bring up very valid points. VMPS products tend to be capable of good bass extension but typically sound bass heavy due to the slower transient response of a passive radiator. Obviously, speaker placement is critical and i'm assuming that you've experimented in this area first. If you haven't done this, that would be the first step before you start anywhere else.

If you can't get the system to do what you want it to do after finding proper speaker placement, I would contact Brian Cheney and start looking at the tuning of the passive radiator. By changing the tuning of the drone cone via adding / removing mass, you will alter the quantity and quality of bass that you hear. It is possible that a previous owner had "fine tuned" the mass of the drone cone to better suit their personal needs / room acoustics. Since every room is different, it is possible that what worked for them sonically / acoustically may not work for you.

As to the equipment that you have, i do think that cables can make a difference and sometimes this difference can be quite noticeable. Having said that, i'm not familiar with the interconnects but the speaker cables tend to favor bass output, so those are obviously not the culprit.

As far as your CD player goes, changing tubes can / will alter the presentation and tonal balance. I would work with getting the speaker situation sorted out prior to even remotely thinking about tubes though.

Looking at your back-bone components ( preamp and amp ), i don't know the output impedance of the preamp nor the input impedance of either of them. This could come into play and might be something that you want to check into. When a component is not properly loaded, it tends to either sound overtly lean or excessively slow and murky.

As far as the amp itself goes, it should be left on at all times for best performance. Aragon's can tend to sound a tad hard & bright and slightly lean in the mid-bass ( warmth ) region if you cycle them off and on all the time. Obviously, if you can slightly soften the highs a bit ( not so much soften as "refine" ) and increase the warmth of the system, tonal balance will be slightly fuller sounding.

As far as the bass capabilities of the Aragon product line, i would stick with what you have rather than looking at a Bryston as Marakanetz suggested. The Aragon is a FAR better amp than the Bryston in terms of bass output and control. This is especially true if running at lower impedances, which if the VMPS that you have is like their other designs, probably is.

As a side note, when setting up speakers on the long wall, you tend to have a more open soundstage due to the lack of early reflections, but you also pick up some bass reinforcement from sitting in closer proximity to the rear wall. Going to a short wall placement will produce an increase in apparent high frequency content as you're now hearing a larger percentage of reflections. At the same time, you'll also lose low frequency coupling as you're probably sitting further away from the rear wall. Depending on the speaker design, one placement will work better than others. As far as personal tastes go, i normally prefer speakers on the long wall. Then again, most all of my speakers are sealed, so the added bass reinforcement that occurs in such a situation isn't as "bad" as if one were using vented ( passive radiator, ported, etc... ) designs to begin with.

Obviously, my suggestions are simply "comments" and should be taken as nothing more than a reflection of my personal tastes and observations. Others may have differing points of view. So long as you arrive at the place you want to go sonically and we ( as a group ) are able to help you do that, that is all that counts : ) Sean
Great points made above. Speaker positioning is generally a good starting point. Your room dimensions aren't bad so that shouldn't cause too many problems. I assume you have a fairly standard room -- i.e., not too many large openings into other areas, not too many hard surfaces, a decent amount of carpeting and cushioney (is that a word?) furniture. If not, then start with the room itself, especially if it seems like the speakers are throwing out decent bass if you put your ear (or meter) right next to the woofer.

I also assume that the lean bass comes across whether you use your tuner or cd player so I wouldn't look for answers there, at least not right away. If it's easy to borrow a decent preamp, you might want to switch that out to see if it makes a difference (by the way, as Sean suggests, it may be the amp/preamp cable rather than the preamp itself if the borrowed preamp sounds better -- i.e., impedence/inductance/capacitance matching may be off). Finally, you might want to borrow other speakers and see if that makes a difference. If so, then you may have some worn parts. Visually inspect the woofer cones for tears or cracks -- if they are there, replace the cones. If everything still looks good, consider replacing the capacitors in the cross-overs as a final last resort once you determined it is the speakers.
Sean, whattafool I always mistake Aragon for Adcom i.e. finger with ...&^%$% if you know what I mean...:-)

I think you nailed it with amp/pre synergy since the output impedance of L1 is arround 2k.
FWIW if you system has an upper midrange emphasis it might lead you to believe you have reduced bass or midbass (a general lack of warmth). A couple of your components are not (IMHO) tilted toward warmth and are neutral at best, but should not cause a lack of bass. I agree with previous comments that you should investigate proper room placement of the speakers and the listening position, using a RS meter and a good test CD. If you have not already do so you should check out the various theories for room placement, such as Cardas. Rives has a nice web site. Both are good for some begining understanding and as starting points.
Moving your speakers closer to the back wall will ad some boundary reinforcement to the low end. But you could muck up the low mids and imaging. The better solution is to move the listening position so that you are sitting as close to the back wall as possible. Antinodes (the part of the waveform with the highest amount of displacement) occur at room boundaries. As long as you sit with your head no further than 1 1/4 feet from the back wall, the bass will be at a higher amplitude, and the mid to high frequency reflections from the back wall will be so short, that your brain won't be able to distinguish them from the direct sound. If you want more info I think AudioPhysics has some info on their website regarding this monitoring scheme.

you'll get much more of an effect (you can expect ± 10dB/spl below 200Hz in some rooms) with speaker/listening position placement than you ever will with cables or electronics (other than an EQ). Save your money, take a little time, and if that doesn't work, then think about altering your equipment.
I have the RM 40's and so does a friend. He used the TACT device - very expensive and somewhat complicated to get a fuller and more controlled sound. I had a thin sound in my room and tried the Peavey Kosmos - it did the job. Say what you want but everything sounds thin without it. I also have one in my Focus 20/20 system. It can be bought direct with a 30 day trial. All this other advice is very good but the Kosmos cuts out a lot of the trial and error and makes a huge difference and you can put your speakers where you want in the room.
I second the Peavey. It stopped the black hole where my money was going for EQ, black boxes, etc. Great piece.
Will Kosmos work with TOO Much Bass?
Creeper, thanks for the input. Yes from all that own the tower 2/R's or the Super Tower R's there hasnt been one person i have heard complain of thin bass.

Sogood 51, when i purchased my tower 2 R's they were an easy 8/10. The original owner never touched the putty and it was in its factory position when i purchased them. I have removed about a small pea amount from each PR in hopes of correcting the problem. As far as using the bottom post i use the top posts with 12 guage jumpers to the bottom posts with switch in up position. I have read this is a great tweak to tighten bass and improve the image and tonal balance. John Casler is the one who brought the idea to the forefront and many are very pleased with the results. Now i am not sure if that might indeed be the reason that i am experiencing thin bass. Might need to give your idea a try. thanks.

Marakentz, lol. Seriously though i want to try and stay with my aragon if at all possible it is a very clean smooth sounding amp in my system. Don't really know what everyone means by bright if anything i would call it on the neutral to warm side more than bright.But that could be from the other components i have it matched with.

Jond, You might be on to something there. But thin is thin and i think i might have another issue here.

Elevick,I am very happy with the mids and highs and if i move them back closer to the wall i seem to lose the magic so i would like to look for another alternative. And as for the second part of your question its yes i ordered NOS 6H23-EB's from Kevin at Upscale Audio.

Sean, thanks for your comments and opinions. I might just need to rearrange my speakers to the long wall.I was trying to find other alternatives without having to make such a move but it might be necessary. A question about leaving my amp on all the time. Wouldnt that require me to leave my preamp on all the time as well? Reason i ask is because i was thinking that would wear out tubes rather quickly leaving the preamp on all the time and i was afraid to leave amp on and turn off preamp. I truly believe the synergy i have found with the amp and preamp is truly amazing in the midrange and highs. But i sure would like the added pleasure of some fuller bass.

Ozfly, the speakers are an 8/10 with no signs of wear on any drivers. All drivers are working perfectly. Another point you make on when i am up close to the speakers i do notice quite an increase in bass. Just seems not to be moving across the room. Not sure whether i could have a problem with crossovers but they sure are playing beautifully with the exception of thin bass.

Newbee, upper midrange emphasis gives me headaches and causes me to fatigue with time. I am not experiencing that with this combination of equipment at all. Thanks for the recommendation of an RS meter and test cd. I think that is something i really need to look into.

Alcides,thanks i appreciate your advice and recommendations.

Ljgj, thanks for the advice i will surely give the Peavey Kosmos a look.

Lpg, thanks for the input.
I would bet money that this is not a componant issue, but a room issue! Check out They have helped me a lot!

It is amazing how much difference proper setup, and room taming can make. I have had some of the pieces you own and they did not have the 'bass shyness' you are concerned about, which is why I would blame the room.

Good luck!
Cables and cords are good way to tune a system, but it may be better to make sure everything else is matched first.

Tubes are also a good way to tune your system, but you seem to have everything dialed in and the bass may be tough to solve by changing 6922 tubes. In my system, changing 6922s have altered the sound in more than one area of the sound spectrum.

I checked the specs on the input sensitivity for your Aragon 400 mkII and it's rated at 22Kohm, which is in the same ballpark as the 23Kohm Pass Aleph 3 which I had trouble mating to my Blue Circle BC21 preamp. If the output impedance of your Audible Illusions L-1 is 2Kohm as Marakanetz says, that may be the reason right there. Previous A'Gon posters have mentioned a guideline range of 10 to 100 times [preamp output impedance to amp input impedance] and your set up is sitting on the very low end.

Do you lack dynamics if you turn the volume up? Along with the thin bass, this was another problem I experienced with the Aleph 3. A real shame because no amp has done guitars as well in my system as the Aleph 3.

Is it possible for you to substitute another amp in place of the Aragon just to see if that has an effect? Also, what's the output voltage on your CAL Icon? If that is too low it's possible the AI L-1 doesn't have enough gain to compensate for that.

Good luck and let us know how it goes.
Nrchy, thanks for the recommendation and the confidence in the equipment matching. I will take a look at the site.

Gunbei, the dynamics of my system sound great to me. The instruments are sounding as they should. I am getting a nice wide soundstage, not incredibly deep but wide. As I increase the volume the bass does increase and the music comes alive. I just figured with this set up i would have more trouble with being overly bloated as to being shy. I really think i need to address placement at this time.

I spoke with Brian Chenney today and I informed him of the trouble. He asked about putty and I told him that I had removed about a pea size amount so far and he said that I wasnt there yet and keep going. Also he said to try removing the jumpers and just using the bottom posts with the switches down. I also informed him i was using an aragon and he said look elsewhere for the problem. It more than likely is setup with speakers or room. To much magic for me to believe i am having a synergy problem. Thanks all for the recommendations and advice I am going to start putting some of your knowledge to work.
Kool 39, You just said something that got my attention - that is, that you have to turn the volume up to make your speakers come alive! I don't know what you were running before you got the VMPS, but one of the common issues with dynamic speakers is the need to crank up the volume on some models. I replaced my Quad 63's with 3 way dynamics which use Dynaudio drivers and that was the first thing I noticed - how much louder I had to play them to get them to sound full - and thankfully how much better they sounded loud, as opposed to the Quads. That may be part of your problem ....just different performance from different types of speakers. Also, for what its worth, I have a room 2 feet shorted than yours and my speakers are pulled out from the back wall 5 feet, they are 2 feet from the side walls, they are toed in to cross in front of me to help reduce sidewall reflections caused by close placement to the side wall, and the listening position is 4 1/2 from the back wall. Soundstaging is excellent and I'm flat to a slight rise at 32hz with a fall of starting at 28hz. A lot of patience, the RS meter, and a good test disc helped a lot to dial in the speaker location as well as the listener location. My speaker location coincided with the one recommended by Rives site (I found his site after I did all the hard work). Good luck......
"Need some audiogon expertise" by the number of posts above all that comes to mind is "Too many cooks spoil the soup."

Better luck next time.
Newbee, I do notice quite an improvement with volume. I think you make a very good point. I use to own very efficent speakers which didnt take much volume at all to get them playing very dynamic. Then i moved to a more warm speaker that took lots of power to make them sing and they didnt last long here in my home. With Vmps i do like the dynamics at low levels just seems to be a little thin. But I have found by walking around the room to different areas the bass is increased in specific locations. So with the combination of such a dynamic speaker that does need a certain amount of power and the present placement of my speakers i have created this weakness. I will be working on my placement at this time. Thanks for all the advice.

Bowbow, obviously you have never been part of a phenomena know as "brainstorming". If i didnt want the experts to come forward with their opinions i would not have asked for help.I would have just sat in dissappointment for another 6 months wondering what might be my next alternative.

Thanks again all for your advice and recommendations.
Kool, from what you describe even though the specs say otherwise, it seems you might NOT be experiencing impedance mismatching with your preamp and amp.

I agree that experimenting with speaker placement would be the best place to start. Try pushing them closer to the back walls. Hopefully you can achieve a balance where bass fills out without becoming boomy or muddy, and soundstaging doesn't suffer.

Good luck.
Gunbei, thanks for the advice. I was looking at my audible illuions L-1 manual and it states that the output impedance is 1.2Kohm. The aragon 4004 mkII does have an input impedance of 22Kohm. This tells me i am on the low side of the of the guidline range but also i am well within it at 18 times. Not completely sure that some of the problem doesnt lie in this area but with the dynamics as such i highly doubt it.
Output impedance usually is correctly specified in the manuals but the freequency range sometimes isn't or if even specified the levels usually hidden.
Preamp might be at fault of not having "full-enough" range and needs either internal upgrade or replacement.
I'd increase negative feedback or introduced the global feedback if one is absent in the amp. Also I'd replace stock volume control on alps pots.
For a replacement I'd look for Audio Research older units that are far more superior than L1.
Marakanetz, The frequency response is specified in the manual and it is within 1dB from 2 to 100khz. So i do believe it has the audible range covered. The preamp seems to be working perfectly absolutely dead quiet. Music comes out of the blackness. There is no noise present when i turn the volume controls. Not sure what you are talking about with global or negative feedback. The aragon is an ss amp by the way. Thanks for the input.
I have had one experience where the 4004 MKII had such a high damping factor that the bass was swallowed by a 'floppy' room. By 'floppy' I mean suspended wooden floor or thin walls etc. In the same room a fairly basic tube amp managed much 'better' bass than the Aragon simply by being less damped.
i'm not talking of the aragon amp.
i'm talking about preamplifier that might not have in reality specifications for a full range.