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adding two small subs on front left+right speakers

post #1 of 56
10/16/11 at 7:42am
Thread Starter 
Have a decent 7.1 system right now (nothing special at all):

Receiver = Onkyo TX-SR806
front/left/center speakers = (3) Jamo E770 tower speakers
side/back surround speakers = (4) Snap-Audio in-ceiling 8" speakers
LFE subwoofer = Velodyne DPS-12

I'm fairly happy with this setup, it's in our living room, usage: 70% HT & 30% music (Pandora) & bluray concerts. I found some nice 8" Jamo subwoofers for a really good price. Thinking of buying 2 and hooking them up in-line with the front left & right speakers for more "character" when listening to music (which I always thought was lacking with my current setup). Right now, the receiver's filters are set at 70Hz for the front tower speakers (THX recommended), I'm thinking of setting them down to 40Hz (or "full range") once I add the two small subs to the front.

Has anyone done this? Any feedback appreciated!
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post #2 of 56
10/16/11 at 8:39am
Are you saying you don't use your Velodyne DSP-12 when you listen to music?
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post #3 of 56
10/16/11 at 9:05am
What's your current crossover set for the towers? Might want to turn it down and let the towers work a little more
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post #4 of 56
10/16/11 at 8:15pm
Thread Starter 
The receiver has a builtin THX auto-calibration (using a wired mic) system, and I'm pretty sure it has optimized all the crossover frequency settings properly. It originally set the front speakers to cut out @ 50Hz (& redirect to the LFE subwoofer), but I raised it up to 70Hz after extensive testing with bluray movies & listening to my music collection... to my ears, this setting produced the cleanest sound. However, when listening at lower volumes... it seems to lack something in the lower bass range (like I'm not getting the full range). That's why I'm thinking of adding 2 small subwoofers inline with the front left & right towers, then setting them both to "full-range", and just let the big 12" Velodyne sub do LFE & surround lower bass.
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post #5 of 56
10/16/11 at 8:48pm
If your looking for low deep bass your going about it in the completely wrong way. The deep bass that you speak of comes from large subwoofers and not speakers or small subs. Using your speakers full range i think is counter productive without an external amp and especially if you have a subwoofer available. People would use these small subs you speak of as flank subs or mid-bass modules to help out the mid bass which is that slam feeling you get in your chest when listening to music. If you want that visceral feeling during movies that makes glass flex and drywall crumble then you need some large big boy subs. THERE IS NO REPLACEMENT FOR REPLACEMENT.

What is the size of your room in cubic footage, and can you give me an idea of a budget?

Would you be opposed to building it yourself or having someone build a custom high powered sub(s) for you?
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post #6 of 56
10/16/11 at 8:54pm
Thread Starter 
sorry for the confusion, I meant mid-bass (or fast bass?) for music (what I feel is lacking with my setup). The 12" Velodyne sub seems to handle low-bass (40Hz and down) just fine on movies... but I would like to upgrade that too later on (I've already set my eyes on Epik Empires).

Concept is like this:

Receiver --> front left&right audio signal set to "full range" ---> small subwoofers outputs signals less than 70Hz --> tower speakers outputs 70Hz and above
+
Receiver --> center & all surround signals crossover at 70Hz (current setup) --> Velodyne DPS-12 subwoofer outputs LFE & all the rest of the "filtered" audio signal
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post #7 of 56
10/16/11 at 9:19pm
Quote:
Originally Posted by khaliss View Post

sorry for the confusion, I meant mid-bass (or fast bass?) for music (what I feel is lacking with my setup). The 12" Velodyne sub seems to handle low-bass (40Hz and down) just fine on movies... but I would like to upgrade that too later on (I've already set my eyes on Epik Empires).

Concept is like this:

Receiver --> front left&right audio signal set to "full range" ---> small subwoofers outputs signals less than 70Hz --> tower speakers outputs 70Hz and above
+
Receiver --> center & all surround signals crossover at 70Hz (current setup) --> Velodyne DPS-12 subwoofer outputs LFE & all the rest of the "filtered" audio signal

If your interested in a mid-bass module check out the MBM by HSU. You could also make your own or have something custom made for you using a heavily braced cabinet. Rather than connecting them to the speaker inputs you might be better off using as external crossover like minidsp or DCX2496 by Behringer. These will allow you to set separate crossovers for each sub.

For example:

Let your current sub handle everything below 50hz and redirect your two new MBM's to play 50-120hz.

My recommendation would be to invest in some kind of room measurement software to figure out what you actually need to improve upon rather than shooting in the dark.

I also like you thought I needed to invest in some MBM's to compliment my 4 15" subs. I ended up adding a 5th 15" sub to the rear of my room and it greatly helped flatten out the response in the 60-120hz area. A 6th 15" sub will be joining the lineup this week for the opposite side in the back of the room this week to hopefully even further improve my response while adding to my headroom at the same time.
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post #8 of 56
10/16/11 at 10:53pm
Thread Starter 
Mpray, that sounds like some crazy setup hehe... I wish I could afford that many 15" subs. I'm really on a tight budget, to the point that I'm only willing to spend $100-$150 for each of the small (& cheap) subs for the "mid-bass" thump that my setup seems to lack. I've seen inexpensive subs with speaker (high-level) IN/OUT with a built-in crossover adjustment knob which would suit what I have in mind:



so basically, I could set my receiver's crossover filter to "40Hz" for the front left & right speakers... the front left/right speaker terminals from the receiver would go to the "HighLevel input" on the subwoofer, set the sub's knob to 80Hz (which would effectively let the sub play only 40hz-80hz), and lastly, the "to speaker" terminals would then go the front tower L/R speakers
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post #9 of 56
10/16/11 at 11:49pm
I was just talking about this earlier today with someone, and after thinking about it tonight, I do not believe it to be a good idea.

With the size of the rooms we are working with, the subwoofer response is completely room dominated. The whole point of running multiple subwoofers is for balancing the modal response of the room as bass below ~80hz is nonlocalizable. In order to get the benefits of multiple subwoofers they need to be getting the same signal at all times.

I would skip the Jamo's and keep an eye out for a used matching Velodyne dps 12. Identical subs are much easier to work with. Best thing you can do if you haven't already is figure out what your frequency response looks like. Could be you have poor room response and a sub or seat move or distance setting on sub tweak could make all the difference and you wouldn't even need another sub. When you say the 12" Velodyne sub seems to handle low-bass (40Hz and down) best, the first thing I think is setup problem, because it should perform well above 40hz.
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post #10 of 56
10/17/11 at 3:48am
Khaliss, I suggest you go for it. I've been running a system with a similar setup to what you describe for many years. Using a pair of small subs as mid-bass modules located near the L&R speakers gives you total control over the mid-bass because you can dial it in independent of the LFE. You can also cross them over to the main speakers as high as you like without concerns about localization. This winds up leaving more power reserves in your receiver, resulting in cleaner mids and highs. The small sub pair can be run in stereo if you wish.

The down side is that it does complicate the setup quite a bit when it comes to setting levels, getting the phase just right, and eq. If you don't mind tweaking, I think the results are worth it. To me, the biggest payoff with this setup comes with playing music. The kickdrums and bass are just right.
LL
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post #11 of 56
10/17/11 at 9:27am
For a little bit more, instead of 2 inexpensive 8" subs, consider one Emotiva Ultra 12 at $379 shipped. The Ultra 12 is known for being a nice, tight sounding sealed sub that is good for music.
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post #12 of 56
10/18/11 at 8:14am
Hi Khaliss,

I have an Onkyo SR-876, and set up two additional subs for front left and right like you are thinking of doing (I don't buy that base between 40 & 120 Hz is not localizable). What I did was to run sub-cables from the receiver pre-amp front left and right out to the two subs. On my receiver, the pre-amp out is before the base management, so the cross-over to the sub-woofer (which I have set at 80 Hz) doesn't apply to the pre-amp outs. By hooking them up this way, I am able to tweak the fronts and main sub as normal, and then to dial in the front left and right subs using the gain and cross-over dials on the subs themselves.

I think this is a lot simpler than trying to run the full signal to the front left and right speakers through the speaker wire and have the subs cross over the speaker signal. If your receiver doesn't have pre-amp outs, you should try the tape-out. I'm pretty sure these outputs will bypass the base management also.

The only thing to be careful of is ground-loop isolation. If you get some strange ground-loop hum problems that are not solved by ground-loop isolators, see my other posting on what I did wrong and the extremely simple fix.

--Mark
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post #13 of 56
10/18/11 at 10:27am
Quote:
Originally Posted by DrMark View Post

Hi Khaliss,

I have an Onkyo SR-876, and set up two additional subs for front left and right like you are thinking of doing (I don't buy that base between 40 & 120 Hz is not localizable). What I did was to run sub-cables from the receiver pre-amp front left and right out to the two subs. On my receiver, the pre-amp out is before the base management, so the cross-over to the sub-woofer (which I have set at 80 Hz) doesn't apply to the pre-amp outs. By hooking them up this way, I am able to tweak the fronts and main sub as normal, and then to dial in the front left and right subs using the gain and cross-over dials on the subs themselves.

I think this is a lot simpler than trying to run the full signal to the front left and right speakers through the speaker wire and have the subs cross over the speaker signal. If your receiver doesn't have pre-amp outs, you should try the tape-out. I'm pretty sure these outputs will bypass the base management also.

The only thing to be careful of is ground-loop isolation. If you get some strange ground-loop hum problems that are not solved by ground-loop isolators, see my other posting on what I did wrong and the extremely simple fix.

--Mark

Are you sure bass management is not applied to the pre outs? That would mean you would have no bass management if you used an external amplifier for any of the main speakers. It has to be applied to the subwoofer pre out, so why wouldn't it also be applied to the rest?

-Mike
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post #14 of 56
10/18/11 at 10:31am
If you want to add any bass bin/subwoofer to your main speakers. Simply by a MiniDSP.

You will need a Left/Right Pre-out on your AVR or pre/pro then you connect the left/right Pre-outs to the miniDSP then connect output1 to your main speaker amp, connect outpu2 to your subwoofer/bass bin amp.

MiniDSP has software that will allow you to set your filters/XOs needed to blend your new full range main speakers nicely together.
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post #15 of 56
10/20/11 at 10:50am
Thread Starter 
thanks all for the feedback!

I've pulled the trigger on this deal:
http://slickdeals.net/forums/showthread.php?t=3439928

(2) Energy S10.3 10" subs at $199 each (free shipping) =)

My plan has changed a bit. I'll use these two new subs in parallel (using a splitter) and do LFE duty. Turns out, my VelodyneDPS-12 has the speaker-level inputs I'm looking for with active crossover/filtering (so that front L/R speakers would only get 80Hz & above audio signal for cleaner sound reproduction). Will also set L/R channels to "Full-Range" setting from the receiver side.



Freakn' excited to try out my new setup!
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post #16 of 56
10/20/11 at 11:07am
Quote:
Originally Posted by DrMark View Post

What I did was to run sub-cables from the receiver pre-amp front left and right out to the two subs. On my receiver, the pre-amp out is before the base management, so the cross-over to the sub-woofer (which I have set at 80 Hz) doesn't apply to the pre-amp outs.

Quote:
Originally Posted by ironhead1230 View Post

Are you sure bass management is not applied to the pre outs?

Yep, on most AVR's the bass and time management settings ARE applied to the pre-outs.
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post #17 of 56
10/20/11 at 11:09am
Quote:
Originally Posted by khaliss View Post

I've seen inexpensive subs with speaker (high-level) IN/OUT with a built-in crossover adjustment knob which would suit what I have in mind:



so basically, I could set my receiver's crossover filter to "40Hz" for the front left & right speakers... the front left/right speaker terminals from the receiver would go to the "HighLevel input" on the subwoofer, set the sub's knob to 80Hz (which would effectively let the sub play only 40hz-80hz), and lastly, the "to speaker" terminals would then go the front tower L/R speakers

You would need to determine whether the subwoofer is high-passing the speaker-level outputs or not. Some subs do, some do not. But when they do, the high-pass filter is fixed at a particular frequency. It is not adjustable. The sub pictured here, as is often typical, has its low-pass adjustment improperly labeled as a "crossover". It's not really a crossover adjustment as it only adjusts the sub's low-pass filter setting. If this sub's speaker-level outputs are high-passed, then you could connect a pair of speakers to them and use the "crossover" adjustment to adjust the sub's low-pass to essentially approximate the functions of a real crossover.


Quote:
Originally Posted by khaliss View Post

Turns out, my VelodyneDPS-12 has the speaker-level inputs I'm looking for with active low-pass filtering (so that front L/R speakers would only get 80Hz & above audio signal for cleaner sound reproduction).

I think you mean "high-pass filtering", don't you?
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post #18 of 56
10/20/11 at 11:39am
Thread Starter 
Quote:
Originally Posted by sivadselim View Post

I think you mean "high-pass filtering", don't you?

Errr... yes, sorry for my typo.

So, that means using my receiver's pre-outs (instead of the speaker-level outputs) would pretty much equate to the same thing?
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post #19 of 56
10/20/11 at 11:45am
Thread Starter 
Siva, what do you make of this: (from Velodyne DPS-12 manual, page7)

S p e a k e r L e v e l O u t p u t
When connected in this fashion, your satellite speakers will be fed the same input signal as the
subwoofer. This removes the lower bass from your satellites, enabling them to do a better job
reproducing high frequencies and giving your receiver’s amp more headroom (up to 50% more
power). You may also connect your satellites directly to your receiver or amplifier along with the
subwoofer if you wish to bypass this crossover.

http://www.velodyne.com/pdf/dps/dps_manual_english.pdf
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post #20 of 56
10/20/11 at 12:27pm
Quote:
Originally Posted by khaliss View Post

Siva, what do you make of this: (from Velodyne DPS-12 manual, page7)

S p e a k e r L e v e l O u t p u t
When connected in this fashion, your satellite speakers will be fed the same input signal as the
subwoofer. This removes the lower bass from your satellites, enabling them to do a better job
reproducing high frequencies and giving your receiver's amp more headroom (up to 50% more
power). You may also connect your satellites directly to your receiver or amplifier along with the
subwoofer if you wish to bypass this crossover.

http://www.velodyne.com/pdf/dps/dps_manual_english.pdf

What do I make of it? It's amazingly inarticulate (and perhaps inept). It initially says "When connected in this fashion, your satellite speakers will be fed the same input signal as the subwoofer.". Then it goes on to say that "This removes the lower bass from your satellites, enabling them to do a better job reproducing high frequencies..........." So, which is it? Yes, it would seem that the speaker level outputs are high-passed. But at what frequency?

They also say that in using the high-passed speaker-level outputs, you are ".......giving your receiver's amp more headroom (up to 50% more power).". This is wrong. The amplifier is still amplifying the same full-range signal prior to sending it out to the sub when you use a speaker-level connection, whether you connect your speakers to the sub's (supposedly) high-passed speaker level outputs or not. The only way to relieve an amplifier of having to amplify the lower frequencies would be to connect it to a sub that features high-passed low-level (pre-amp level) outputs, thereby applying the filter prior to the amplification stage. This sub doesn't have those.
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post #21 of 56
10/20/11 at 12:36pm
Thread Starter 
^Yes, the first couple lines do sound conflicting... that's why I got confused and asked how you understood it. But as long as there's high-pass filtering prior to the audio-feed on the sub's speaker-line out terminals, then it *should* have an impact on how "cleaner" the signal will be to the satellites (in my case, the tower speakers).

Overall, what do you think of this setup? There's going to be a lot of tweaking I'll need to do for proper volume leveling LOL
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post #22 of 56
10/20/11 at 12:54pm
Quote:
Originally Posted by khaliss View Post

But as long as there's high-pass filtering prior to the audio-feed on the sub's speaker-line out terminals, then it *should* have an impact how on clean the signal will be to the satellites (in my case, the tower speakers).

Right. Assuming you are sending a full-range signal to the sub (LARGE speaker setting), as long as there IS high-pass filtering, the speakers will be relieved of having to reproduce the full-range signal. But there is no real benefit at the amplifier as they would have you believe.


Quote:
Originally Posted by khaliss View Post

Overall, what do you think of this setup? There's going to be a lot of tweaking I'll need to do for proper volume leveling LOL

Well, honestly, I am still not really sure of how you are proposing connecting everything. Correct me if I am wrong but it seems you want to high-pass a pair of sub/speaker combos off the Velodyne? Is that right?
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post #23 of 56
10/20/11 at 1:12pm
Quote:
Originally Posted by sivadselim View Post

Right. Assuming you are sending a full-range signal to the sub (LARGE speaker setting), as long as there IS high-pass filtering, the speakers will be relieved of having to reproduce the full-range signal. But there is no real benefit at the amplifier as they would have you believe.

Why do you say there would be no real benefit at the amp? If the bass is filtered off, it will mean that less is asked of the amp in the receiver. While due to speaker-level crossover losses it might not be as beneficial as when the crossover is done at the pre-amp level, it still will make the amp have to work less hard.
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post #24 of 56
10/20/11 at 1:13pm
Thread Starter 
Revised setup:

Receiver L/R speaker level out (set to FULL range or "LARGE") ---> Velodyne DPS-12 speaker line-in (sub filter set to 80Hz) ---> L&R speakers connected via DPS-12 speaker line-out

Receiver's Center & side/rear surround speakers (set to 80Hz). Two Energy 10.3 subwoofers connected in parellel via a splitter to receiver's LFE (sub pre-out) jack.

By the way, the receiver is an Onkyo TX-SR806 (THX certified, 7.1, 130Watts/channel RMS, with pre-outs)
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post #25 of 56
10/20/11 at 1:20pm
Quote:
Originally Posted by khaliss View Post

Revised setup:

Receiver L/R speaker level out (set to FULL range or "LARGE") ---> Velodyne DPS-12 speaker line-in (sub filter set to 80Hz) ---> Tower speakers connected via DPS-12 speaker line-out

Receiver's Center & side/rear surround speakers (set to 80Hz). Two Energy 10.3 subwoofers connected in parellel via a splitter to receiver's LFE (sub pre-out) jack.

By the way, the receiver is an Onkyo TX-SR806 (THX certified, 7.1, 130Watts/channel RMS, with pre-outs)

The big problem with this setup is that your primary sub, the Velodyne, will not be getting the heaviest bass which is in the LFE (Sub pre-out) jack. The heaviest bass will instead be sent to the energy subs which are not likely to be up to the task of reproducing LFE at high volume.
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post #26 of 56
10/20/11 at 1:22pm
Quote:
Originally Posted by mojomike View Post

Why do you say there would be no real benefit at the amp? If the bass is filtered off, it will mean that less is asked of the amp in the receiver. While due to speaker-level crossover losses it might not be as beneficial as when the crossover is done at the pre-amp level, it still will make the amp have to work less hard.

Because the receiver's amp still has to amplify a full-range signal. The bass isn't being filtered off. The subwoofer's high-pass filter is where the energy will be dissipated. It's the same as the argument against there being any benefit at the amplifier of doing a passive biamp. The amplifier is still being sent, amplifying, and sending along a full-range signal. The energy from an amplifier connected to the tweeter, for example, in a passive biamp is dissipated at the speaker's crossover.

Now, whether, because the load on the other end is not really there, there is some relief on the actual amplifier, I honestly am not sure. I have had this discussion before and was convinced by others that the amplifier is still working the same amount.
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post #27 of 56
10/20/11 at 1:28pm
Thread Starter 
Quote:
Originally Posted by mojomike View Post

The big problem with this setup is that your primary sub, the Velodyne, will not be getting the heaviest bass which is in the LFE (Sub pre-out) jack. The heaviest bass will instead be sent to the energy subs which are not likely to be up to the task of reproducing LFE at high volume.

Based on the numbers here: (Tom Nousaine's lab tests)

Energy S10.3

20Hz @ 84db SPL
104db average SPL 25 - 62Hz
108db maximum SPL @ 62Hz
Bandwidth Uniformity @ 97%

Velodyne DPS12

Bass limit 20 Hz @ 80 dB
Average SPL from 25 to 62 Hz 103 dB
Maximum SPL 110 dB at 62 Hz
Bandwidth Uniformity @ 94%

(2) S10s would definitely be better than (1) DPS-12 on LFE duty, right?
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post #28 of 56
10/20/11 at 1:31pm
Quote:
Originally Posted by khaliss View Post

Revised setup:

Receiver L/R speaker level out (set to FULL range or "LARGE") ---> Velodyne DPS-12 speaker line-in (sub filter set to 80Hz) ---> L&R speakers connected via DPS-12 speaker line-out

Receiver's Center & side/rear surround speakers (set to 80Hz). Two Energy 10.3 subwoofers connected in parellel via a splitter to receiver's LFE (sub pre-out) jack.

Now, this, I do not really understand. You are going to use the single Velodyne, to augment the front speakers' full-range output but use the 2 Energy subs to reproduce only the LFE channel and any rerouted bass from any channels being crossed over (SMALL)? This is not the way you started this thread.

Whether this is your intention or not, bear in mind that the Velodyne's varible low-pass setting does not dictate its high-pass filter frequency. This is fixed at a particular frequency. It is usually in the range of 80-120Hz. But, whatever that high-pass frequency is, you would want to adjust the Velo's variable low-pass to something that is appropriate for your room and listening preference. This may or may not be the same (or similar) frequency as the high-pass filter frequency that is being applied.
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post #29 of 56
10/20/11 at 1:37pm
Quote:
Originally Posted by khaliss View Post

(2) S10s would definitely be better than (1) DPS-12 on LFE duty, right?

Well, based upon those numbers, yes. But I would take those numbers with a grain of salt. They may be correct. They may not be. They may have been generated a little differently.

What is "confusing" us here, is that you have gone from the idea of augmenting each of your front speakers with it's own small sub to something that is almost the opposite. Using a single, larger (albeit maybe less capable) sub to augment your front channels and using two smaller (but albeit perhaps more capable) subs to reproduce LFE and rerouted bass.
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post #30 of 56
10/20/11 at 1:38pm
Quote:
Originally Posted by khaliss View Post

Revised setup:

Receiver L/R speaker level out (set to FULL range or "LARGE") ---> Velodyne DPS-12 speaker line-in (sub filter set to 80Hz) ---> L&R speakers connected via DPS-12 speaker line-out

Receiver's Center & side/rear surround speakers (set to 80Hz). Two Energy 10.3 subwoofers connected in parellel via a splitter to receiver's LFE (sub pre-out) jack.

By the way, the receiver is an Onkyo TX-SR806 (THX certified, 7.1, 130Watts/channel RMS, with pre-outs)

Quote:
Originally Posted by mojomike View Post

The big problem with this setup is that your primary sub, the Velodyne, will not be getting the heaviest bass which is in the LFE (Sub pre-out) jack. The heaviest bass will instead be sent to the energy subs which are not likely to be up to the task of reproducing LFE at high volume.

Here is a possible solution to consider:

1. Run the LFE output to ALL three subs.
2. Set the crossover for the L&R fairly high, perhaps 100 or 120hz.
3. Use the crossovers located on the subs to control how much upper bass
content each sub actually reproduces.
4. For the two Energy subs, run a 30hz or a 50hz FMOD in-line highpass filter to remove the deeper bass from the Energy's.
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