i am purchasing a pioneer 47a to go with my 950 and i was wondering if any one that has this setup can tell me the proper way to configure the speakers in order to get proper bass control. also am i correct in assuming i will need 6 extra cables? sorry for my ignorance.

For DVD-Audio and SACD playback, you will need six extra analog cables -- and you will want to leave any bass management options set to "off" (all speakers large) so that the analog bass management on the 950 can handle it. For DVD-Video (DD/DTS decoding) and CD playback, you will probably want to rely on the digital output from the 47a to the 950, leaving the 950 to implement digital bass management and D-A conversion. (See Kevin Brown's post in this thread from earlier today -- he has a 47Ai and a 950 configured just this way).

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

i just got back from out of town. thankyou for responding.

holecz- Let me know if/when you have any questions. I agree, it is complicated!

Question for Kevin C Brown: How do you have your subwoofer configured when using the 5.1 analog inputs? I experimented with my cd player analog outputs hooked up to the 5.1 analog input and the bass was really boomy with the analog 80hz xover engaged, is this the double bass anomaly? My main l/r speakers are set to small.

Here's how I did it:

I use the digital crossover in the 950 for all CD/DVD-V sources. (In other words, I use the coax digital connection to pass CD/DVD-V sound to the 950, and let it convert to analog.)

I adjust all the levels in the 950 so that I get about 0 dB with the speakers, and -5 dB for the sub. You have to specifically raise the volume of your sub to do this. (Note, I do *not* reference to 75 or 85 dB. I just "match" levels.) In the 950, I have all speakers as small with respective crossover points: 80 Hz mains, 120 Hz center, 80 Hz surrounds/rears. (I could go 60 Hz for the mains, but just easier to keep them at 80 to match the analog crossoevr in the 950.)

So then for DVD-A and SACD, I pass that to the 950 via the 5.1 analog connection. So in the 47ai I have all speakers set as large, with the sub on. (Let the 950 do the analog crossing over.) Have to make sure "6 ch bypass" is on in the 950.

So in the 47ai, I have all the levels set at about 0 dB for the speakers, and about +5 dB for the sub. Takes care of the 10 dB "boost" that is automatically applied for DD/DTS signals to the 950.

I use Avia to set the levels in the 950, and the Chesky Ultimate (DVD-A / DVD-V) test disc to set levels in the 47ai.

Beware: the sub test tone in the Pioneer player is hosed. Way too low. So if you are using that to set the sub's level, you will get bass that is way too loud.

Kind of complicated, but I was surprised how well it all works together once I got it all set up...


[This message has been edited by Kevin C Brown (edited February 22, 2003).]

I just got a DVD-A last night and have spent most of the day tweaking and listening. I am very impressed with the sound in both hi res stereo and hi res surround but there are two things about the 950 that have me bent. Both have to do with the " 6 Channel Direct" connection. First is the summing of the below 80Hz no matter what you do. Second is if the optical input is set to play stereo then the "6 Channel Direct Mode" only plays in stereo, not 6 channels.
What is up with that? 6 Channel DIRECT should be DIRECT, period, nothing else added (exept volume adjustment), nothing taken away. If the music producer wants 80HZ and below on the .1 channel then they would put it there. The analog bass managment switch only manages bass for everything except the speaker that only plays bass.
As to only getting stereo from the analog 6 channel direct input when a completely different digital input is set to stereo boggles the mind. Why should one effect the other? Again direct should be direct.
Sorry for the rant.

Incorrect. If you engage the 80 Hz analog crossover, everything works as it should.

And as far as the "6 ch bypass", you are correct, but it is a known bug. You have to be in a 5.1 DSP mode before you switch to 6 ch bypass to get all 5.1 channels (DD/DTS/5 ch stereo, for examples).

Same bug also effects the test tone generator. Have to be in a 5.1 (or 6.1 or 7.1) DSP mode, or else you only get 2 channels out of it.

Kevin- It is interesting that the Pioneer allows you to turn on the subwoofer when all speakers are set to large. My JVC does not allow this. Do you get to set a crossover freq.? Seems to me there would be nothing in the sub channel as DVD-A does not have a dolby-like LFE track. Of course this is as it should be to avoid the bass doubling that results from having the player do bass management.

Kevin, I don't understand why you think the statement is incorrect. There seems to be no way to NOT have the 950 sum bass. Bass management switch set to OFF sums bass, switch to ON also sums bass.
I knew about the bug for the test tone but I didn't realize that would also effect the 6 channel inputs. I have read other posts where the questions have been about the difference of using stereo bypass and just two channels of the 6 channel direct. It appears that stereo bypass would be the choice if you want to pass signal as cleanly as possible. Can someone explain why this analog signal path has anything to do with a DSP mode from another source?
After all is said I am getting very good sounds coming from the system but I feel it could be better if I had a little more control.

all redirected bass is summed with lfe in all bass management, digital or analog.

when the 950's analog BM is switched 'off' satellites get full range signal and subwoofer gets below 80hz and lfe. that is a doubling of bass below 80hz into the satellites and the subwoofer.

when the analog BM is switched 'on' satellites are high passed at 80hz and below 80hz from the satellites goes to sub with lfe. there is then no doubling of 80hz and below.

actually, some view the switching setup as logical...not a bug. when you are in a stereo digital mode and you switch to 6 ch bypass, only stereo direct is connected. when you are in a multichannel digital mode and 6 ch bypass is selected, 6 channel analog is connected. 6 ch bypass has nothing to do with the dsp. sacd has both stereo and multichannel formats as well as redbook cd, depending on what disc you buy, so switching from digital playing of the cd layer to stereo sacd makes sense as it's configured. switching from the cd layer to multichannel requires hitting a multichannel digital button first.

Thats my issue, bass management set to OFF should mean there is no management. I was looking for a way to not have the 950 "redirect' anything, just pass thru what is being fed. To me it's like the THX thing where all speakers must be cut at 80Hz.


Apparently it does if I need to have a DSP effect set a certain way to allow a completely different input (6 channel analog direct) to play it's 6 channels.

Neal- As far as I know, DVD-A and SACD do support 5.1, so that there *can* be a dedicated LFE channel.

Keta- As far as bass summing on the analog 5.1 input, the Rotel 1066 does the same thing, just that it does not have the 80 Hz analog crossover, so that you cannot get rid of the "bass doubling." Somewhat "well known" issue with both processors.

Kevin, so you are saying that there should be no bass summing with the analog 80hz engaged and using the 5.1 analog inputs? How come when I route my cd player analog ouput to the 5.1 analog input the bass becomes really boomy? The cd player analog output to the cd analog input and using analog bypass sounds great. I have been thinking about getting a pioneer 47a universal player and that is the reason I was experimeting with the 5.1 analog inputs. Thanks for all your input by the way.

JAMMINJC- I was thinking one thing, and wrote another. What I meant was, when you do engage the 80 Hz analog crossover, everything works as it should it terms of the high pass filtering, the low pass filtering, and no double bass. Obviously, when the analog crossover is enagaged, you *do* get summing to the LFE channel of all the info from the mains below 80 Hz. Just that there is no double bass, because the mains are high passed at 80 Hz as well.

With the 80 Hz crossover off, you get summing to the LFE *and* full range mains, which gives you "double bass."

Now, as far using the 5.1 analog input vs bypass mode on a two-channel analog input: you will also get double bass on the analog 2-channel input if you have your speakers selected as small. You will get full range mains, *and* summed bass to the sub. My understanding is, if you set your mains as large in 2 channel bypass mode, the 950 turns off the sub, so no double bass, just full range mains.

I haven't really listened to much analog 2 channel bypass (the 950's DACs are good enough for me), so I can't really comment on the differences between that and the 5.1 analog input, except to say that's how it's *supposed* to work.

Thanks for your response Kevin. You are correct in the 2 ch bypass mode, if mains are set to large, no sub and if mains are set to small you get 80hz xover and sub.

On my system I have the mains set to small and the sound between the digital inputs and the 2ch analog bypass is so close I can't determine which is better sounding. But when I experimented with the 5.1 analog inputs (just using main l/r inputs) the bass became boomy and the overall sound was inferior in my judgement. Could this have something to do with the phase issue?

Well, only if you're out of phase to begin with!

Let's say you're out of phase for DVD-V's and CDs. The bass will sound as it sounds. You adjust your sub's level that way. You get used to it, so that sounds "normal". OK, now when you switch to the 6 ch bypass, you will now be *more* in phase, and hence the bass *should* sound louder, and potentially worse.

For 2 ch bypass, it's full range mains and no sub anyway, so no phase issue there. But, if you do have the speakers set as small, you will get double bass being *in phase" with the mains and sub, and that should sound bad too.

So...

- 6 ch bypass, in phase, boomy bass
- 2 ch bypass, small mains, double bass, in phase, boomy bass
- 2 ch bypass, large mains, phase n/a, good sound
- 2 ch digitally, out of phase, sounds good because that's how you have your sub's level set, and that's what you've become used to

Maybe? BoB?

One quick note concerning phase. I 1st tried to adjust the phase between my mains with the tests in Avia. I thought I got it right, and I was seemingly happy for a long time. Then I got a discrete test tone CD (Autosounds 2000 #101, or Stryke). I rapidly figured out that I had it wrong. When I *properly* adjusted the phase, my sub was then too loud. So it can happen very easily. The Chesky Ultimate DVD-V/DVD-A is a very useful disc for phase, and for a whole bunch of other stuff too. Avia is good for most things, but a waste for mains-to-sub phase IMO. The Chesky disc has phase tests that are a lot easier to judge if the phase is correct or not.

Avia and the Chesky disc make a nice combination.


[This message has been edited by Kevin C Brown (edited February 26, 2003).]

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sounds like a good assessment to me.
2 ch digital, mains set to small...flip the phase invert switch on your sub and see if it becomes boomy (make sure you're at the listening position to assess the difference after you invert the phase).

if so, KCB is correct.

BTW...once you get the uni player, this 2 ch through the 6 ch bypass will be moot...you'll never do that again. but, it will tell you how to set the phase switch for each format.

recommended discs for the new uni player:
SACD: spyro gyra 'in modern times'. james taylor 'hourglass'. in a week... pink flloyd 'dark side of the moon'.

dvd-a: yes 'fragile'.

dts-cd: sting 'brand new day'. alan parsons 'up in the air'. (any player)

Any chance this can get into a step-by-step or FAQ for us novices?

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sure...ask/answer/inform/be informed IS the general outline of this forum. it's the place to get to the bottom of any sort of 950 or related industry question. with people like sanjay, charlie, soundhound, KCB, SLL, etc., it's kind of crazy not to ask.

my stance on bass management and dvd-a/sacd with the 950:

the 950's analog BM has double bass when switched to 'off' (because 80hz and below will then be fed to the 5 satellites AND the subwoofer). here are the facts:

1. if you choose to shut the BM off, the low frequency dynamic range of dvd-a/sacd formats WILL exceed the capabilities of your satellite (fl, c, fr, sl, sr) speakers.

2. the correct placement of a single subwoofer in a given room is very difficult because of peaks and/or valleys in the response curve caused by room modes (the reaction of soundwaves in a given shaped confined space). at least, you have the option of moving your sub to find the best overall sound at the listening position. if you shut the BM off (assuming you would NOT have double bass), you now have 6 'subwoofers' all at different places in the room...a room mode excitation/phase problem nightmare...AND 5 of them can only each be precisely placed in the room with no option to move them around.

3. if you ignore facts 1 and 2, even if you didn't have the double bass situation, you would lose some bass content and hear a distorted low freq playback at the listening position.

these facts don't excuse the double bass situation, which is a mistake. they only make it a moot point, since a fixed, single high pass point for all satellites and a properly placed sub with a corresponding low pass point is the best playback method (this is also how they are monitored during the mixing of the discs) for dvd-a/sacd multi-channel music in the case of the 950 and a single subwoofer with these formats.

this makes it easy....dvd-a/sacd are decoded inside the player, sent out of the player via 6 rca cables to the 950's corresponding 6 analog inputs. switch bass management to 'on' (on the 950's rear panel). adjust your sub's low pass point to 80hz. play a song you like in either format that has a repeating single bass note type of riff while sitting where you listen. switch the sub's phase switch and play the same riff again. leave the phase switch at the position that plays the loudest bass. calibrate the 6 speakers as to volume level using a radio shack spl meter. i'll leave the speaker volume calibration details to someone else if anyone asks. in fact, each of these steps can easily be gone over in greater detail. this will lead to the greatest possible enjoyment of any dvd-a/sacd/950/5 satellite/1 sub setup.

I'll give my two cents on this issue since it is my major gripe with this otherwise very good preamp.

1. The whole idea of dvd-a/sacd bass management (redirecting bass) works well if you have satellites and a single sub. If you have full range speakers (which I do on all except center) BM is not needed! Nor should it be wanted.

2. I recently added another sub for "stereo subs". The best thing I ever did for my system. The subs are fed L/R line levels and also the LFE mono. In all situations (except 6ch input) all speakers play full range and the subs just augment the lowest bass for the fronts. With the current 950 BM setup you get the double bass with BM set to off and you get mono bass with BM set to on.

The mono bass is what I don't like. I don't think anyone would like it if their stereo only setup forced mono only bass from their speakers regardless of their speakers capabilities.


I don't agree. Every DVD-A I have puts very limited bass to the center and surrounds. As I said my center won't play deep bass but they don't seem to be trying to. I don't think the producers are channeling that much bass to the centers or surrounds and even if they did the speakers just won't reproduce it.


I again disagree. I have three subs and it was much easier to balance the bass response in the room because multiple subs help fill in each others peaks and valleys.

It just bothers me that the inputs used for DVD-A/SACD force you into a certain configuration. These two formats are currently my highest quality sources and the 950 is putting me into a box with the forced mono bass summing.

I would like SH to please describe how he handles this BM issue (or lack of) with his stereo subs if he even uses the 6ch inputs.

Keta- I hear ya , but I would have some questions. You say you have full range speakers. -3 dB point is 20 Hz? *And*, you have tested that with a calibrated microphone and a software package something like ETF so that you know that you are only getting direct, and not reflected (bass augmented) sound? I know that a lot of manufacturers put forth the claim that they have "useable" output down to 20 Hz, but that is something like - 10 dB, not - 3dB. -3 dB at 20 Hz speakers do exist, but they are rare and do cost some denaro.

Even if you do have full range speakers, crossing them over *will* help them sound even better because driving low freqs is not easy. (I bet BoB and SH can phrase this better than I can. Better dynamic range in the the midrange.)



Ahhh, but you are balancing the valleys of 1 channel with the peaks from another? That's not right. The goal should be flat response with *each* sub, and not with all three going. Otherwise for example, you're filling in the valleys from say the left channel speaker with bass from the right channel. That's different content!

The best rule of thumb I ever came across for multiple subs? Stack them all in the same place. Whether it's a corner, or along a wall.

Then there's the question of sure, they can reproduce 90 db at 20Hz (1 watt or so) but what happens when a reference level or higher (say 100 watt) signal gets sent out - can they really reproduce a 110 db note at 20Hz? Pretty unlikely.

As for stacking subs, lots of folks like it, but I don't. My personal best results have been (1) corners of a symetrical room and (2) a horizontal line array. Maybe this is what Kevin means by 'along a wall'?

YMMV.

Charlie

DITTO! I don't own a 950 and it offers alot to make me want one, but this just may a deal breaker for me. 5.1 direct should be just that, DIRECT, no summed bass, no nutin'.
Has anyone investigated what it would take to modify a 950 to defeat the summed bass? I'd hate to break an otherwise great warranty to fix a design flaw (IMHO), but if it is possible to modify then I might consider a purchase. Now there is the missing LFE on DTS-ES. I really wanna like this pre-pro but it's getting more difficult the more I read about some of these quirks. Hey, no product is perfect but these seem to be pretty basic issues (at least they are with me).


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Tekdredger

[This message has been edited by Keta (edited March 06, 2003).]

[This message has been edited by Keta (edited March 06, 2003).]

what anyone 'thinks' producers are doing with sacd/dvd-a doesn't negate the fact that they are formats that are capable of 6 full range channels. i own several sacd discs that contain full range surround tracks and several others that have unfiltered kick drum in the center channel (and my sacd library doesn't put a dent in the list of available software). at low enough volumes, this won't hurt the speakers, but the information on those tracks isn't being reproduced when BM is switched 'off', if there were no double bass, that is. at ref level, the center speaker, in most cases, will clack or be damaged. in any case, who knows what is yet to come with both formats?

as far as 20hz capable floor standers, i've never heard one. in fact, most subwoofers don't display useful spl at that freq or below. how is it that a subwoofer can augment a full range speaker?

if you're attempting to make, say, 4-ways out of your front left and right 3-way speakers by splitting those 2 channels through 2 subwoofers, that, by itself has nothing to do with bass management. also, if the 2 subs are not each equidistant from the listening position with the front speakers, you have phase problems.

though i agree that multiple subs are easier to place in a given room, 'place' is the key word. they can't be placed just anywhere. the point i tried to make, is that the 5 satellites cannot be moved around the room, rather, their placement is very critical to a successful surround soundfield. placement of a sub is not the same as placement of a full range satellite. 5 'full range' satellites cause phase anomalies...period. we've tested and verified this fact.

which discs do you believe contain 'stereo' bass information? maybe i could benefit from an explanation of 3 subs and how they deliver stereo bass when summed with LFE (this is no sort of loaded question, i really would like to learn more about your setup).

the point of my previous post was in answer to a question from a self proclaimed novice and the subject of the thread is the 950's analog BM and connection of sacd/dvd-a players to the 950, not a list of the 950's shortcomings. i remember being absolutely cross-eyed at the whole BM situation...industry-wide...not just the 950. a simple 'place to start' is required. i found it in this forum and appreciated it very much.

SH is waiting for a uni player that suits him.

Kevin - I would consider my speakers full range.
Front - NHT 2.5i biamplified with a spec of 29Hz -3db. Each front speaker is also augmented by it's own NHT SubTwoi with a spec of 21Hz -3db.
Rear - NHT 1.5 each high passed through it's own Polk PSW650 28Hz -3db.
I run these speakers this way because when bass is coming from front left, I want to hear it come from front left. I have read and heard people say that bass is omni directional and I don't believe it. Just listen to good old straight stereo with subs in stereo and while listening unhook one and you will notice the difference. With my set up I can also make the subs mono or stereo and stereo is far superior IMHO.

Exactly what I want, left from left, right from right. This is especially true when playing DVD-A/SACD where bass can be coming from anywhere. Example would be playing something multichannel and a bass guitarist playing at your rear left and only the +80 HZ coming from that speaker and the -80HZ coming from a single sub in front of you in an opposite corner. It seems people spend most of their money on speakers to try and get this great sound stage with depth and width and then try and squeeze an entire section of frequency into one box in a corner. I went a different route with my speakers and IMO the BM on the 6ch input really hurts the potential for DVD-A/SACD through those inputs.
As a side note concerning this 20Hz figure. My youth was spent listening to lots of rock way to loud and this showed me something while testing the frequency response of my setup. I was playing individual test tones using the SPL meter to get readings. My 9 year old daughter was sitting in the room with me wondering why I would sit there and listen to these stupid sounds. Anywho when I start off at 20Hz I cant hear the noise only the various items rattleing throughout the house. I could feel the bass but couldn't hear anything until 30Hz. The same was true on the upper end with 18kHz being my upper limit. I mention my daughter because she could everything (20-20k)even at low volumes. My point is now I don't care if my speakers will play 20Hz or 20kHz at 120db because I can't hear it, but what I can hear in between sounds good.
Don't forget STEREO subs, it's worth it. SVS should love me

bosso - I agree that full range can be sent through all six channels but my limited DVD-A collection has not shown that in most cases. I also 'think' that most of us are not listening to everything at reference levels at all times so feeding those not so "full range" speakers a frequency they can't produce doesn't hurt anything as long some discretion is used with the black knob.
Just a difference in the definition of a "full range speaker". I usually consider a speaker full range if it can produce healthy bass below 40Hz. Maybe if I explain the front sub setup it would help. My NHT subs need to be handled by a controller. Each sub has just an on/off and an RCA feeding the amp. The controller allows for line level as well as LFE inputs.(also speaker level) You can high pass through the controller but I don't, that is handled somewhere else. Anyway the controller allows you to adjust main volume(line level inputs) and LFE gain independently for mixing in the desired amount of LFE. Low pass for each is handled seperately. So I take the front L/R outputs from the 950 split them one going to the sub controller and the other going to seperate sub amps driving the lower sections of the main speakers. I listen to most things with front speakers set to large.The full range signal used by both the mains and the sub with the sub low passed at around 40Hz allowing it to "augment" the deepest bass as the mains start to drop off in repsonse. The rears each pass through their own sub which is high passed at 80Hz making each of them acting as "full range". The rears are being fed with speaker level inputs so if I were to activate the 950's BM I would essentially remove all bass from the rears. Each speaker is in close relation to it's sub so they act as an entire unit making placement easier to me.
As for specific stereo bass on any songs I will have to go through and check but again I 'think' there is stereo bass in most recordings, maybe not a lot of seperation but can notice it quite often. It's subtle but it's there.
I also consider myself a novice and am thankful for this forum. This forum IS the reason I bought the 950/770. I was not looking for a way to point out the 950 shortcomings but following the original posted question of the correct way to hook up a 47a and I think the BM issue needs addressed for this. I hope tekdredger buys the 950 and trys it out for himself. I think given everything he will be very pleased.

keta: thanx for the details. i understand now some things i could only guess before.

the solution to your dilemma with this setup is a simple one:

since, when you switch to 6 channel bypass, you are only using the 950's preamps section, you can take the player's analog sw output and run it into a separate preamp (you can use a mono mic preamp and they start at about $65, but i would use a better one. see behringer shark or art @ zzounds or use any preamp you might already have lying around). from there you can input it into your controller. switch the 950's BM to 'off'. since there is no longer anything plugged into the 950's sw output, there will be no double bass and the system will work as you want it to.

when you switch to a digital source, the question will be: does the analog output of the player get the lfe signal, or the digital connection, or both? if your player sends the lfe to both or the analog output, you're good to go with all formats.

as far as protection of your center speaker, use caution with sacd discs. some send serious bass to the center.

also, i highly recommend consulting KCB about phase issues. this is a very important tweak in a system like yours and kevin has it locked.

i appreciate your input.

Keta- Where do those specs come from? The manufacturer?

I'd have more faith in them if it's either from a Stereophile speaker review, or if you go to the louspeaker reviews here with the NRC logo, they also have comprehensive measurements:

www.audiovideoreviews.com

I used to lust after stereo subs too. But with the interference effects across the room, and the fact that bass below about 80 Hz is omnidirectional anyway (doesn't matter where you put the sub, the bass seems to come from "everywhere"), just makes them more hassle than they are worth IMO.

Oh yeah, if you *don't* think low freqs are omni-directional, play your favorite panning effect with low freqs and the crossover engaged. But turn off power completely to your high passed mains. I guarentee that you won't be able to tell where the bass is coming from. Turning off power to your mains eliminates the higher freq components that provide the "cues" with which you think you are hearing the directionality of the low freqs. THX didn't pick the 80 Hz crossover for nothing...

Here's the link to the analyzer software I use with my PC:

http://www.etfacoustic.com/

The demo is free. I heavily recommend it if you haven't done this kind of analysis for your room. It's an eye opener... I used to use a Radio Shack meter with a discrete test tone disc too. This is much faster. And because it's so much faster, you can do a lot more plots that *really* investigate what's going on in your room.


[This message has been edited by Kevin C Brown (edited March 07, 2003).]

kcb: absolutely excellent link.

Just to cast some additional light on my preference for stereo subs:

Consider an omnidirectional stereo pair of microphones placed in front of a stage at about 15' distance apart (not uncommon). Now imagine a bass drum at the left of the stage hitting a note. That low frequency information will reach the left microphone almost a full wavelength's time before it reaches the right microphone. That bass drum sets up a complex field of phase related peaks/valleys that mix acoustically and vary over time before it reaches your ear. Stereo subs will reproduce this sound-event and it will mix acoustically in your room just like it did in the original recording venue, which will increase the realism. If that same stereo low frequency information were to be summed electronically as it is with a single mono subwoofer, all this spatial information will be lost.

That is my main arugment for stereo subs.

At least in my case, I can tell the direction of low bass by sensing "pressure" from the direction of origin. It is not so much "hearing" the bass direction as much as
"feeling" the bass direction.

Keta- There is "somewhat" of a workaround to the double bass problem on the 950:

1) Set up the DVD-A/SACD player as all large speakers with no sub. The player (if it's doing BM correctly) will reroute the LFE info to the mains.

2) Just to be safe, do not connect the LFE channel from the player to the 950.

3) 80 Hz analog crossover off in the 950.

4) Turn off your sub.

So you would get full range mains, no LFE signal, but that info has been rerouted to the mains anyway. No double bass, all low freq info intact.

Not perfect, but it does work.