Help wanted: Bass!

I’m in need of augmenting the bass in my system. I’m the old school type and would rather NOT go the sub route.

My system and environment:
• Pre:   Conrad Johnson Premier 16LS
• Pwr:   Conrad Johnson Premier 12 Mono Blocks
• Pwr Condtnr: Shunyata Hydra
• Speakers: Tannoy Kensingtons
• Cabeling: Stealth PGS IC’s, Vandenhull Bi-wire Speaker wiring
• Sources: Conrad Johnson DV-2B CD Player, SOTA Star w/SME arm w/Grado cart, Magnum Dynalab Tube Tun 
• Music:   Classic Rock, Easy listening, Female Jazz singers, Classical
• Room:   Big (25 X 30) w/cathedral ceiling. Harwood floors/ceiling and big glass windows. Rugs and furniture

Came across the Emerald Physics Bass Manager claims to add 1/2 octave of bass to any speaker. IYO, could that be a solution? Are there similar helpers like this out there? Not much in the budget (about $500) for a near-term purchase. Could double that for a longer-term.

Again, not wanting to go the sub route unless I have too. Can’t do room treatments or alter room configuration (it’s our living room) either.

Any thoughts/suggestions will be greatly appreciated – thank you!

Hi RB!

I would say spend no money until you have your hands around the neck of the problem. :) I might TRY some solid state amplifiers, just to see if what you have is an amp/speaker mismatch, as well as different amp taps. 

The usual order of improvements should be:

  1. Room treatment
  2. Bass Traps
  3. Subwoofer
  4. Equalization
Too often I see something like "I want the best possible sound, but I want no room treatment, subwoofer or equalization." :D :D So I hope after measuring you can be flexible to get what you need.

It's a real shame that you are not more amenable to room treatment, but that will have to wait until we know what the problem is. GIK has an entire line of treatments that can be painted on, you can get any designs you want on them. Their sofit bass traps disappear into the corners with the right cloth cover.

Let's start with a near zero dollar approach.  Get Room EQ Wizard and a calibrated microphone and stand.  The cheapest calibrated microphone is the Dayton iMM6, but it's so small it's a pain to use on a stand. Great with a phone or tablet though. Better is the UMIK-1. 

Measure your frequency response as well as bass decay from your listening location.

Come back when you have a quantitative idea of the problem.


By the way, OmniMic is a better choice, but it's about $250 and will eat into your budget fast.
One thing, where are your speakers relative to the walls and corners? The usual simple fix for more bass is to put the speakers up against the wall, and then in a corner.

I just assumed you had tried that.
RB, my listening room is similar to yours, though a bit larger, at 16' X 34' w/cathedral ceilings. Speakers are custom built 12" Tannoy HPD's (ca 1975 Dual Concentric, which have been converted to Hard Edge surrounds, and custom outboard crossovers).

The bass was good without subs, but I felt I could use more bass in my large room. I added a 15" Tannoy passive sub, which I power with a Crown XTi 2002 (1600 Watts when bridged to mono, into 8 ohms), and a DIY 12" sub w/Eminence subwoofer driver. These two subs have put the finishing touch on an already good sounding system. The bass is very good, not at all overstated.  I couldn't ask for more, I feel a closer connection to my music, which now has a foundation that gets me to where I need to be. Nothing much to do now but listen to music in a very satisfying way.

I wouldn't rule out subs for your situation, the right sub(s) might just be what you need to finish your system off. 

Hope you find what you need, regards,
Cables and even power cords can make quite a difference when it comes to bass. But it requires experimentation and it won't be inexpensive.
The Tannoy Kensington’s are easy to drive,, but their lowest impedance is in the bass. Have you tried different impedance taps on your CJ 12’s? As these can make big differences in bass performance.

Stereophile test CJ12’s:

The Twelve comes with the output transformer wired for 4 ohm use, but dealer-selectable taps for 2, 8, and 16 ohm operation are also provided.

Cheers George
Post removed 
Wonderful suggestions, thank you all.

Beginning with no cost suggestions, I already have the Kensington’s placed by each side of my fireplace which puts them about a foot away from the back wall and about same from the wall of the fireplace. This did help some.

George suggested trying different impedance taps on the CJ 12’s. That’s an intriguing idea which I’ll certainly be looking into…

I do appreciate how room treatment and bass traps would help. However, I should have mentioned earlier that this is our living room and the décor in place is firm. My wife would (and I’ll go along with her) not want any changes to what we have. It’s a very open concept log home and has had it’s décor tuned to a final state and it’s not to be messed with.

Solid state would boost the bottom end but I love tube electronics and will stay the course.

Makes good, no great sense that I need to analyze the room with a measuring device – thanks for recommending this and I’ll do that to “get my hands around the neck of the problem” as Erik so well put it! Need objective data to really gage the issue. I’m 55 and sometimes I wonder if it’s just my aging ears!

This all may lead to purchasing a sub, as much as I would rather not do. Dan mentioned how he’s enjoying one with his Tannoys. Dan – perhaps you remember talking with me a few years back about Tannoys (I saw yours in a pic and complimented them which got us going). Cosmetically the Kensingtons are perfect for our décor and I do love the mid-range they offer.

Thanks again everyone for such great advice, and interestingly enough is that not much talk about an EQ took place here…where I was originally “at” but have since moved on from!

Best regards,

I'll vote with Eric....get some measurements so you can analyze what's really going on before playing the 'musical equipment swap' game or other high $ experiments.  Treating the room (which you'd rather not do anyway) can be avoided with active eq, but that's MHO and upsets the purists.

Personally, I ignore the room and 'run' flat response, but that's my thing and not to everyone's taste.  But, to each...
Fireplace!!!!!   That's it.  Your lows are going up your fireplace.Block your fireplace, close the flue, etc.   I had an attic fan in my lows until I got a powered louver for the big hole in the ceiling.
maybe a Speltz autoformer?
Have you tried rolling some different 6922s in your preamp?
All great suggestions from everyone and each in it's own way will add its own incremental improvements to your in-room bass response. I was in the same spot as you (and also own and use Tannoy D700's) but I didn't get the bass I was really looking for until I added a subwoofer. Good luck!
I have Westminster GR in a good size room that is engineered and treated. I added Audiokinesis Swarm subs to add that last bit of low end I wanted and could not be happier.  Yes, there are 4 but their footprint is small and integration is seamless. Adding this to echo Mike on not ruling out subwoofer as the answer. 

Good luck on finding your solution and happy listening!
I love the CJ Premiere 12's by the way. One of my all time, if not all time favorite amplifiers. If only money and space allowed!


This may prove cogent 
Appears the obvious sure-fire solution would be a sub. Get over my resistance I say to myself!

Question: I'm currently running bi-wire to the Kensingtons. How would this be configured with a sub? Or should that be two subs?? Can the concept of bi wiring still exist with a sub???

Thanks all! I really appreciate the responses!  
Post removed 
Hehehe, well, if you are going the sub route, that means you can add a miniDSP in the sub's chain, without disturbing your mains.  Excellent..... :)


All right, this discussion thread has brought me to now wanting to look at subs. 

I do not see  "subs" as a sub-category (no pun intended) under the speaker category. How do I find them on Audiogon? I did a key word search of "sub" and came up with about a page worth's. Is that the best I can do?

One other question: What's "standard practice"... One sub or two?



Do get the knowledge to try to change the speaker output impedance taps yourself first, before spending any money.
You have 4 different ones to try and you maybe surprised as the ported 10" Kensingtons have usable output down to 20hz (-10db). See frequency response, 1st graph near the bottom, the red trace is the port bass output, the green trace is the drivers output, if you visualize the two added together, you see you do have quite good LF bass.

Cheers George
Bob_Reynolds 7-17-2016 5:16pm EDT
If your preamp has a 2nd pair of outputs, then use those for the sub. Otherwise, you can use a Y-connector to split the preamp output between the sub and main amps. The problem with using a y-connector is the effective impedance the preamp will see, which can be a real concern for tube preamps. The impedance of line level connections on subs are typically in the 10K ohm to 20K ohm range.

I would add to Bob’s characteristically excellent comments that in the majority of cases where preamps provide two outputs for each channel both of those outputs are driven by the same output stage circuitry, and are simply jumpered together just inside the rear panel. Which means that in those cases the impedance compatibility concern would occur no differently than if the preamp provided just one output for each channel and a splitter is used.

In this case it appears that your 16LS preamp does provide two sets of output jacks, and according to Stereophile’s measurements its output impedance rises to about 1800 ohms at 20 Hz, while being much lower at mid-range and treble frequencies. Assuming, as is likely, that both output jacks for each channel are driven from the same output stage, the output stage would see a load impedance corresponding to the parallel combination of the sub’s input impedance and the 98K input impedance of your amp. Which will result in an overall load impedance that is less than the individual input impedances of both the sub and the amp.

Therefore if you choose to connect the outputs of the preamp to a sub (or to two subs), as opposed to connecting the outputs of the power amps to sub(s) that can accept speaker level inputs, I would not choose a sub having an input impedance of less than about 20K. 20K in parallel with 98K results in an overall load impedance of (20 x 98)/(20 + 98) = 16.6K, which is already slightly in violation of the 10x rule of thumb guideline for assuring impedance compatibility, relative to the preamp’s 1800 ohm output impedance at 20 Hz.

Good luck. Regards,
-- Al

More excellent posts with advice to a technical level - love it!

Greatly appreciated gentlemen. I certainly feel that I've taken a big leap today in acquiring the needed know how on how to confront and resolve this issue. 

Kindest regards,
Honestly, while I love well-tuned subs, in your case would avoid subs at all cost, because you don't want to do any room treatment.  The deeper in the rooms response you go the more chances you'll have to make the room ring like a bell, and then subs get a bad rep for not being as detailed, not being as good, whatever, compared to the mains.

Your single best bet, after the amp taps, is to measure, and EQ appropriately.

If you said you had flexibility of sub woofer placement, were willing to consider some soffit traps, and began with an EQ in the picture, then subwoofers would be a direction I'd suggest.  Otherwise go ahead, I'll just show up with popcorn.... :)


I just read that the ports also on the Kensingtons are side firing,, make sure they have room to do their thing, and again try the different output taps on the CJ 12's this is where the bass drive, control and bloom will be affected the most. 

Cheers George
rbschauman ... 

Here are some room treatments for folks who don't want intrusive room treatments. They solidify the bass, extend the highs and give you a more focused sound stage. Amazing product.

Get the 10 pack and place them according to the directions in the package. The 10 pack will get you right on your budget. The difference they make is NOT subtle. 

Nothing to lose with a 30 day, full refund, return policy.

Here are the instructions on how to change the output transformers output taps, if your up to doing it yourself.

Cheers George
There was a big thread on subs. As I remember, almost everyone recommended two subs and one pro fellow recommended four.
Fast subs that can integrate well will not and should not be inexpensive. 
Excellent suggestions -guys.

Yes, but subs can be a nightmare if you have no control over their placement, room acoustics or EQ. In this case it's the perfect storm for @rbshauman

I'd get zero.

Given the ability to control at least 2 of the three pre-requisites, I'd start with 1 and see what's missing. The value of a second sub may be smaller than it's worth.
I believe that Emerald Physics is distributed by Wally Underwood at Underwood HiFi.  He also handles the DSpeaker products which include a competing (and IIRC somewhat more expensive) bass eq device.  You might call Wally to discuss the relative merits of each.
Greetings RB,

I have CJ PR12s and an LS 16-2 as well with B&W Signature 30s, Gyro SE SME Benz Ebony CJ PR15, AYRE DSD QB-9 Mac Mini with AQ Diamond USB cable. Since we have very similar systems I thought my experience might be helpful. I too always wanted a little more bass than I had. Initially I had Transparent Ultra speaker cables. MM2s provided more detail on top but nothing in the mid and bottom end. They went back. I got Cardas Golden Ref ICs and biwire speaker cables throughout. This was an all around improvement. They stayed. For years. 
Still thought things could improve so I tried REF Level biwire Anti Cables for speakers. Unbelievable difference in flow, EVERYTHING improved but most significant was the improvement in the bottom end...deeper and freer with no negative effects on the top or mids.
They stayed and are still in use.

As to tube rolling...Currently have KT-120s from Kevin Deal at Upscale in use. Huge improvement in bass weight and dynamics. Immediately apparent and easily discernible.
But not as lush and wonderful sounding in the mids as NOS Tungsols which create the kind of sound I imagine we are looking for when we buy tubes in the first place. These are the tubiest
of the power tubes I've tried. Russian SED C KT 88s were somewhere in the middle and had a good overall balance...more punch than the Tungsols, but not as lush. FYI the driver tubes are NOS RCA 5751s at V1 on the 12s. So IMO if you really want more bass, the new  KT120s will not disappoint. But in adding bass, you will be markedly changing the character of the 12s.

Which brings me to the 6922s in the 16-2. Stock CJ tubes very nice mid range type of tube,
not overly warm and not bright. NOS Tungsrams are really warm and full and lush sounding.
NOS Siemens Rohrs (blue box) are champs at adding tremendous air and a great soundstage. The beauty of the CJs is that you can tune the system to your tastes, but I have yet to find the best of all worlds at any one time.

The Cardas GRs ICs are a good middle of the road approach and my preference is to get the mids sounding as full as I can. The best anti cables ICs are also very good and sound very smooth but yet detailed. With the KT 120s I preferred the warmer balance with the Cardas GRs which I didn't like as much with the Tungsols or KT88s. For those tubes I use the AntiCable ICs. For me, it's all about tuning the system to suit your taste, which changes, for me, from month to month or year to year.

My room is much smaller than yours, so I have no issues with the bass since I added the AntiCable speaker wires. UltraFidelis run by Jonathon Spelt has a great article on subs at his
website He's a Vandersteen dealer and makes a cogent argument for that design philosophy and implementation which makes sense to me in terms of integrating with our systems. But I have no first hand experience with it. I suspect his would be the best approach
but also costs significantly more than you are talking about.

 I do have experience with REL subs (T9 newer) and can say they are capable of adding weight and energizing a large basement room or a large living room (T7older) with KEF LS50s
But these are in systems significantly less sophisticated than yours where integration was not as critical. No shortage of theories and opinions to be debated regarding subs. All I can say is the RELs worked for me in other systems and were a simple, relatively low dollar solution for adding more bass and I thought they represented good value. I was never listening thinking 'boy these don't sound integrated and are disjointed,' I was thinking "man this sounds really good." Buy them used here and you won't get hurt too badly if you decide they are not your cup of tea.

FYI, I have an Audio Research REF5 SE on the rack now. The LS16-2 goes just as deep and is fuller harmonically in the lows and mids. The AR is a  tighter down low but doesn't go deeper. The AR is definitely faster, cleaner, more detailed and more dynamic,  due to the Teflon Caps I'm guessing, but I'm not sure I'd rather listen to it over the 16-2 over the long haul.

So Anti cables, KT120s, Sub should leave you dazed and confused for months to come!

Enjoy the music!
RBP a subwoofer...the cheapest and easiest way to fix your issues..
Since this has not been mentioned:

The first thing to check is the phase!!

Try swapping the red for black connections on the back of the speaker (one channel only), put on a record with some bass impact and see if the bass is better or worse. If the speaker is out of phase bass will be poor and with some speakers and some rooms you may not notice that the imaging isn’t what its supposed to be. So it might be that the imaging will improve as well if phase is a problem.

Another thing that can cause loss of bass is the length of the speaker cables. One advantage to running monoblocks is the ability to place the amps close to the speaker to allow you to minimize the length of the speaker cable. This usually has a bigger effect with tube amps than solid state due to the output impedance of the tube amps being higher. This is exacerbated if the bass region of the speaker is 4 ohms instead of 8 or 16!! Generally speaking a meter and a half is the upper limit with nearly all tube amps unless you have 16 ohm speakers and you don’t. If your speakers are 4 ohms the limit is more like one meter and the cables had better be pretty heavy.

Its also important to make sure the connections on the amps and speakers are as tight as possible. DO NOT OVERTIGHTEN or you might really regret it.

You may also be experiencing a standing wave in the room; often a problem when the room has regular dimensions. If this is the case no amount of EQ will fix it. I advise staying away from EQ as you will find that the EQ exacts a price which is a loss of transparency and musicality. Its better to find a solution by other means. A standing wave can often be cured by moving the speaker somewhat. If you are stuck with the location, back the speaker up as much as you can and fiddle with toe-in.

Of the subwoofer suggestions, I second the Swarm made by Audiokinesis, should you find that subs are indicated.
I would suggest  trying a aftermarket fuse, first the pre amp, then your splendid monos, I recently switched to Audio Magic's new
SHD fuses, they make you realize just how weak that link really is,
I have been using after market fuses for over 10 years, the SHD is mind boggling, and it wont just be better bass! At 175 each seems expensive till you put one in! Good luck, and really nice setup BTW  
More suggestions, gosh this is great – thanks all!

Some quick hitters:

I conferred with CJ was told that phase inversion is necessary; it’s the configuration I’ve been running though - check.

Connections are secure – check.

***Speaker cable length….hmmm, maybe a bit of a problem here. For aesthetic purposes (again, this is my living room and not my hi-fi room) my electronics are on one side of the room and the speakers centered in the room. Because of this arrangement, I’ve got two 20’ bi-wire runs of Van den Hul Teatrack hybrid cabling. Kensington SE’s are 8 ohms. Atmasphere: Think I’m losing much here?***

RBP, fellow fan of CJ!! Thank you so much for sharing your CJ experiences for my benefit! Tube rolling is something I’ve never done (always used CJ stock tubes) but will get to. Should be an interesting endeavor, thanks for passing along the characteristics of those you’ve dabbled with. Cabeling? Though I was good there with Stealth PGS IC’s and Van Den Hul to the speakers but I’ll review.

Will look into the fuse suggestion as well – I would have never thought they could make a noticeable difference.

Grateful for all the suggestions, the solution is certainly within!


Did you see this link I gave you before to try, you should.

Cheers George
Three things to try:
  1. Pull out the power conditioner (straight from the wall or a simple power strip was best for me). See if the bottoms come forward.
  2. Try lamp cord or home depot extension cord (twisted wires under the insulation) to see if the sound is warmer (mine was).
  3. Clean all your contacts (solved poor sound several times for me)
I conferred with CJ was told that phase inversion is necessary; it’s the configuration I’ve been running though - check.

Connections are secure – check.

***Speaker cable length….hmmm, maybe a bit of a problem here. For aesthetic purposes (again, this is my living room and not my hi-fi room) my electronics are on one side of the room and the speakers centered in the room. Because of this arrangement, I’ve got two 20’ bi-wire runs of Van den Hul Teatrack hybrid cabling. Kensington SE’s are 8 ohms. Atmasphere: Think I’m losing much here?***

To answer the question- yes. Not only are you loosing bass impact, you are loosing resolution. You'll find it easier to make out vocals if you can shorten up the speaker cables.

(this BTW is why balanced interconnect cables are so handy in a home environment as they can be run very long distances without degradation, allowing for short speaker cables; a topic for a different thread)

However, I was not talking about absolute phase with my phase comment. Phase inversion is something an amplifier might do (our amps are non-phase-inverting) but its possible to hook one amp in phase and the other out of phase by accidentally getting one speaker cable hooked up wrong.

When this happens the woofers are fighting each other- you get cancellation in the bass frequencies and so no bass impact. That is why I suggested changing the phase (reversing red for black) on **one speaker only** to test to see if this is the case. Since you have not done so, I suggest you try it and see what difference you hear!
Change out the tubes. I used EI KT90 back when i had the 12s.

If it is a lack of bass impact and not room related suckout, the output tubes made the amps sound as if it gained another 50w of power control and drive over ANY other type output tube, over NOS Gec kt88, Tungsol 6550's.

There is no point taking about tonals of these lusher sounding tubes being better as the bass is the most critical issue you have. Other suggested tweaks will improve resolution, room acoustics but not improving the bass energy which this amp lacks.

The fuses in the amp do not have any audiophile equivalents.
I just saw this here on Audiogon and I think could help you.  Dave

I agree that a sub is a less than perfect solution. I cheated by using identical amps and preamps, respectively for my mains and some good woofers for subs. I have complete control of how much bass I use without any crossover distortion. After many premade crossovers, after learning how to design them myself, and after years of matching subs, I finally tried dual, identical electronics and three inch thick foam for high frequency roll off for my subs, try it. you'll like it.  

Experiment with towels first, a layer at a time. You will be amazed how much better bass can be with no crossovers and a separate volume control that does not change the amount of power by frequency, like a bass control.  

To really get a handle on what's happening in your room, you'd need a sound pressure meter and someone who knows how to use it. Then again, I look at the dimensions of your room (enormous, incl. height); read reviews of your speakers (clearly not intended for a room that large), and it become simpler. You may not want subs, but that's your answer. Subs would relieve your system of the need to fill this giant space below 50-60Hz (a losing battle). If I were you, I'd get a used Marchand crossover (XM9, crossed over low, ~400/500US used); plus 1 X SVS SB1000 ($499 US) to start. You can always get a 2nd sub later. Remember, you're not looking for massive SPLs from the sub, just enough low-Hz presence to lift the rest of the system (which BTW is really excellent in quality). If/when you finally had the $$ for a 2nd sub, the whole picture would be complete.
Your front end looks superb, but the speakers just don't have a lot of bass extension - expect that is the problem.

Switch speakers or bite the bullet and add a musical subwoofer (Vandersteen, Hsu etc.)
Subs seem to get a bad rap because they are almost never integrated properly. It is crucial to get them time aligned with the main signal.
You need a sub with continuous phase adjustment. And the right method for adjusting it.
If you do manage to get bass output for your room, by whatever method,
you will have room modes. The average bass trap doesn’t work very well. Easiest way to manage modes is to get a sub with auto EQ. Just knock down one or two modal frequencies and you are good to go. I feel sorry for my purist friends who have do without bass because subs are not a part of their religion. Listen to the JL Audio Fathoms properly adjusted and you will want to change religions. They aren’t cheap but, considering all the $$$ you’ve put into the rest of your system, to do without such an essential component of true SQ is a tragedy IMHO. Dogma is a b----
I had 2 REL Stadium subs and they were great. I also had a pair of the old HSU tall circular subs made of treated cardboard which were good also. BIG bang for buck. Also pair of Nelson Reed 1204s which can blow down walls but were discontinued at the time of the SF earthquakes. Due to a misunderstanding with my x I" am in an apt and can't use any of these. I would try some of the moveable bass traps, I had a bunch of standard ones on the walls. They were so nice looking my X wanted some on the living room as well. My Karma ran over my Dogma.

I also used large curtains on a wall with no windows, looked acceptable and worked well.
I am glas I use SS, I am OCD enough without having to try a gaggle of tubes
To atmasphere above: viola!  Of course!  And I know better!  Pre amps tend to require speaker lead inversion.  My First Sound PD III and Cary SLP98 before it both do. While swapping out amps and speakers it's easy to forget that.  You just helped me immensely, thank you.  Personally I've had several subs and for strictly two channel I've sold every one of them, or pairs.  Could never get them to disappear.  Overstated bass drew unwanted attention to the subs so away they went.  Decent floor standers should stand in their own, IMHO.  The only add-on I can offer is never underpower speakers. Error on the side of max wattage.  Aside from class 80 watt A monos and an A21, I have the Bel Canto M1000 class D monos and the extra power is more than sufficient to drive most average sensitive floor standers.  Bass is more than a range of frequency response, it's various low frequency instruments. I'm more interested in and pleased with accurate reproduction of instruments, not just 'bottom end'. 
If aesthetics and convenience allow, I have used a 1/4" dowel rod in upper back of speaker to brace the cabinet against the wall, with slight tension by
tipping. It is cheap, reversible, and sometimes works very well. Good luck!