[sunnydaze]

Reason:   main amp is now only outputting 70Hz and above.  It does not contain anything below 70Hz.....which is what the sub needs!

This was kind of my next question. Since the amp is now only getting 70Hz signals and above, does this also make the amp run more efficient? Because it doesn't have to produce the lower frequencies?

Yes.  Also, relieving your single driver of the lower frequencies will allow it to play louder before distorting, so it will sound cleaner, more open and refined, and play with greater ease.  Even at lower SPL's these benefits will be observed.

At least this is what myself and two buddies experienced when high-passing our Omegas.  We all thought the effect was not subtle.

(speakers involved are Super 3XRS,  Super 7XRS mk2,  Super Alnico Monitors.  We all have Gallo CLS-10 sub)

[HiFiJeff]

I think I understand what you're wanting to do...

Option #1

Pre --> 70Hz In-line Crossover --> Amp -->  Speaker Cables to full-range speakers receiving 70 Hz+
                                                           -->  Speaker Cable to speaker level input on 'sub' receiving 70 Hz+ w/ Low-pass set to 150 Mhz
      --> Pre-amp LFE or 2nd Pre-amp output --> Big sub w/ Low-pass crossover set to ~70 Hz

Option #2

Pre-amp Output #1 --> 70Hz In-line Crossover --> Amp --> Speaker Cables to full-range speakers receiving 70 Hz+
Pre-amp Output #2 --> Stereo RCA Cables --> Big Sub RCA Inputs --> Big Sub Low-pass set to play 70Hz and below
Big Sub Pre-amp Output sending 70 Hz+ --> Stereo RCA Cables --> Small Sub RCA Inputs --> Low-pass set to 150 MHz

You got it! Option # 1! That is exactly what I am getting at. This might be a real good option.

[HiFiJeff]

Here is a visual.

I looked up a chart on the frequency spectrum and this is what I found.

sub bass   31 to 62 (and lower)
mid bass   62 to 125
upper bass   125 to 250
midrange   
lower midrange   250 to 500
mid midrange   500 to 1K
upper midrange   1K to 2K
treble   
lower treble   2K to 4K
mid treble   4K to 8K
upper treble   8K to 16K (and higher)

So I want to use my Omega's like this. Main driver 70Hz-20K
Omega deep 8- 70-120
Subwoofer 60Hz on down

This would cover the entire audio frequency spectrum and maybe get fulll efficiency out of every component. I essentially want to use the Omega 8 as a mid bass module, sort of like what HSU used to have.

[HiFiJeff]

Yeah, I have done this before. Not with equipment or speakers of this quality but even in my home theater systems, I would have full range towers and would play with the settings in my avr and almost ALWAYS, I preferred them crossed over at some point, compared to running them full range.

[mrvco]

I was considering keeping my Velodyne sub after I got my Omega sub and doing this sort of setup, but I got a good price for the Velodyne and things were getting a bit more complex than I'd like for my dedicated 2ch system.

[DaveC113]

My buddy is high passing his Super Alnico Monitors with these Harrison gizmos, placed line level between pre and amp.  He tried both the 50Hz and 70Hz, and prefers the 70Hz in his rig.

He says they work like a charm with no detectable sonic degradation.   By removing the lows, he can play the SAMs louder with less distortion, greater purity, and a big holographic soundfield.   He runs his 2nd preamp output into his Gallo sub to fill in the lower range.  Tells me it blends perfectly, with no sub localization.

Says that with this setup, he's getting best sound he's ever had.  I haven't personally heard his rig, but he's very experienced with lots of good gear, so I'd tend to believe him.

Nice, I forgot about line level xos. Probably a good solution, but they do depend on the input impedance of the device downstream to determine xo point. Also, if you have a tube preamp with capacitor coupled outputs it's possible to lower the value of the output caps and make it into a 1st order xo.

Removing the lows does all the nice things you say, if you can get it to work out without degradation of the sound quality and get the sub to blend well it's worth it if you like to play at higher SPLs. If you never crank it up past moderate power levels this whole idea might not be worth it.


HiFiJeff, I'd try to bring the xo up to around 150 Hz or so, there's lots of impact at those frequencies the small surface are of the RS5s can't quite convey as well as larger drivers. Handing off to a dedicated sub around 50-60 Hz will also make the 8s play louder and cleaner. End result will be a "single driver" with full frequency response and high SPL abilities. It'll be better than most speakers on the market regardless of price.

mrvco, it's a slippery slope!  

[sunnydaze]

So I want to use my Omega's like this. Main driver 70Hz-20K
Omega deep 8- 70-120
Subwoofer 60Hz on down

This would cover the entire audio frequency spectrum and maybe get fulll efficiency out of every component. I essentially want to use the Omega 8 as a mid bass module, sort of like what HSU used to have.

Ahhhhh....I see the source of my confusion....didn't realize you were talking about built-in subs AND outboard subs.

High pass your main amp (70 Hz) and connect like this:

(1)  speaker cable,  from main amp to Omega single driver (SD) posts.

(2)  jumper cable,  from Omega SD posts to Deep 8 plate amp posts.  Set plate amp low-pass to approx 120, fine tune by ear.

(3)  RCA i/c,  from preamp outputs to SUBWOOFER inputs.  Set plate amp low-pass to approx 70, fine tune by ear.

If you are successful in obtaining a coherent and natural sounding blend, you should get a clean open relaxed full range sound, that is slightly goosed in the mid-bass.

Just my opinion, but it's a bit complicated / involved for my taste.  Just integrating one sub takes some work.  If the Deep 8 reaches deep enough and moves sufficient air, I'd probably skip the outboard sub.

I tried a similar setup with my Vaughn floorstanders (extended range driver + ribbon supertweeter + onboard 12 inch powered woofer).  LF were already so powerful that adding a pair of Gallo subs brought very little (if anything) to the table.  Just not worth the effort / expense. (Also tried it with a single Gallo sub)

[Carl V]

https://books.google.com/books?id=d7ft6F8ZUdcC&pg=PA15&lpg=PA15&dq=frequency+range+of+typical+instruments


Looking over the graph....
the power region of music isn't sub80Hz
and moving air accurately from 100-500Hz
is not as easy as we assume.

https://www.google.com/search?q=frequency+of+musical+instruments+chart&sa=X&biw=1425&bih=795&tbm=isch&imgil=lLcM8uGqj673QM%253A%253BmF2CVTUYwpbshM%253Bhttp%25253A%25252F%25252Fdjfrobot.blogspot.com%25252F2010%25252F04%25252Feq-frequency-chart-for-instruments.html&source=iu&pf=m&fir=lLcM8uGqj673QM%253A%252CmF2CVTUYwpbshM%252C_&usg=__UdFZRCAXaHItJ2Dt5ufS78rMz8M%3D&ved=0ahUKEwiqkK7UwtHQAhVhjVQKHbEDA2YQyjcIMQ&ei=lFE_WKr2C-Ga0gKxh4ywBg#imgrc=iCHS-v-tTqrq3M%3A

[pstrisik]

Looking at the photo of the plate amp for the deep 8, another option comes to mind.  Louis has speaker level in and out that does high pass.  Run your mains' speaker cables to the deep 8, then from the deep 8 to the monitor.  Set the crossover on the deep 8 to the frequency of your choosing.  That will give you a smoother transition with monitor and built in sub coordinated in frequency and slope.  Should be flat at and around the xover point this way and relieve the mains of lower bass duty.

Run separate preamp out to the big subs.

Disadvantage is if this offends your purist approach, assuming you have one that is.  You would be adding a crossover at speaker level which is counter to the single driver philosophy.  But doesn't cost anything to try and you can see how it sounds.  The gain from lowering the mains' workload may outweigh any loss from running through the sub's crossover.

Edit:  I just reread mrvco's option one and had missed the high pass filter ahead of all this.  That is a better option, IMO.  So, an Emily Litella moment for me! 

[sunnydaze]

...... Louis has speaker level in and out that does high pass.  Run your mains' speaker cables to the deep 8, then from the deep 8 to the monitor.  Set the crossover on the deep 8 to the frequency of your choosing. 

..........

Disadvantage is if this offends your purist approach, assuming you have one that is.  You would be adding a crossover at speaker level which is counter to the single driver philosophy.  But doesn't cost anything to try and you can see how it sounds.  The gain from lowering the mains' workload may outweigh any loss from running through the sub's crossover.

My Gallo sub offers the same exact speaker level high-pass feature. 

Using speaker cables, run main amp into sub inputs, then connect Omega to the sub outputs.  High-pass to the Omega is fixed at 100Hz.  The sub's low-pass can then be adjusted as desired for proper blending.

I had been running Omegas full range, and supplementing LF w/ sub (high level connections). I reasoned that high-passing w/ the sub would muck up signal to mains.  After all, more junk would be in the Omega's signal path => a 2nd set of speaker cables, and the sub's high-pass filter. 

I tried it and much to my surprise, non-subtle improvements occurred.  Even at low listening levels.  I guess the sub circuitry is simple and does little signal damage.     

Or, as you say, if there is any detriment it is outweighed by benefits.  Easy and free to try the sub both ways.

A local buddy had also been using a Gallo sub to supplement his Omega run full-range.  To not impart bias, I didn't reveal my impressions, but asked him to high-pass as I did.   He reported the same improvements I heard, and continues to listen this way.

[HiFiJeff]

After all the conversation and all the suggestions, what I have decided to do is just keep things simple. I went home and did some critical listening and LOVE the way my system sounds as is but it's going to get even better when Louis finishes my dual RS5 driver speakers. And he told me that they are in a completely different league compared to the single RS5 driver. That they will go louder, play more dynamic, and handle complicated music a lot better because of the dual RS5's. I can't wait! Eventually this is going to turn into a surround sound set up and I will kind of separate my critical two channel listening set up from the home theater set up and just use the crossover in the avr for movies and shows and video games and then I have a cd/sacd player going right into my Decware amp for when I want to run them full range. It's a process but I will eventually be where I want.

[sunnydaze]

My guess is.....
Even though you are doubling up your RS5 driver, if you eliminate subs you are gonna miss them.  Just based on my personal experience of listening to a coupla different Omega models both with and without subs, and talking to a few guys that have done the same.....including SAM owners.

[HiFiJeff]

My guess is.....
Even though you are doubling up your RS5 driver, if you eliminate subs you are gonna miss them.  Just based on my personal experience of listening to a coupla different Omega models both with and without subs, and talking to a few guys that have done the same.....including SAM owners.

Oh, I am not going without subs! Subs complete any system that has speakers with small drivers. There is only so much a 4.5 inch driver can do. I am just going to add subs later. I actually might use the subs that are in my current Omega's by running a line level from my pre to them until I get some separate subs later.

[mrvco]

I did get a 50 and 70 Hz pair of crossovers from Harrison Labs.  Initial impressions of the 50's after very limited listening last night was that the low end sounded a bit weak, but the RTA in the Audio Tools app doesn't reflect that, so I'll do some more listening with and without and see.

[HiFiJeff]

I did get a 50 and 70 Hz pair of crossovers from Harrison Labs.  Initial impressions of the 50's after very limited listening last night was that the low end sounded a bit weak, but the RTA in the Audio Tools app doesn't reflect that, so I'll do some more listening with and without and see.

Yeah. Interested in your findings.  What speakers are you running again?

[mrvco]

Super 7XRS MK2 w/ a front-firing DeepOmega8.

It seemed to thin out the impact of the lower end just enough to matter.  I expect that the volume of my space is too large for a single DeepOmega8 on its own (~20'x22'x8'), but it's definitely more than adequate when used in conjunction with the Super7's running full-range.  When I have some time, I'll try again with the DeepOmega crossed over closer to 50Hz.

[sunnydaze]

Super 7XRS MK2 w/ a front-firing DeepOmega8.

It seemed to thin out the impact of the lower end just enough to matter.  I expect that the volume of my space is too large for a single DeepOmega8 on its own (~20'x22'x8'), but it's definitely more than adequate when used in conjunction with the Super7's running full-range.  When I have some time, I'll try again with the DeepOmega crossed over closer to 50Hz.

I have 2 subs, and two full systems setup in different rooms.  So I've been able to try various sub configurations, with a variety of gear -- including 4 different pair of speakers.

I use Omega 7XRS mk2 in a 10 x 11 room with a single 10" sub.  I also have a 2nd system in a 14 x 21 room, with a partial cathedral ceiling -- but still a fair bit smaller than yours.   Haven't tried my Omegas in the large room yet -- I typically use large floorstanders (one pair has self powered 12" woofers) to properly load this big space.  But with my JM Reynaud Twins (2 way monitors) placed in it I much prefer two subs. One definitely helps, but still too light for my taste. 

I realize LF adequacy is very subjective and varies from person to person, but I strongly suspect in a room sized like yours you'd really like what a 2nd sub would add.   Not only LF support, but a nicely improved open  / spacious / dimensional / layered soundstage.  These spatial improvements occur when adding the 2nd sub whether (1) high passing mains and filling bottom w/ subs, or (2) running mains full range and supplementing bottom w/ subs.

I high-pass both pair of small speakers at 100 hz (using the high-pass filter internal to my Gallo sub, everything connected high level), and blend in the sub using its low-pass filter to overlap a bit.   Relieving the mains of LF duty allows them to play louder with greater ease and finesse, and less distortion.  At all volume levels I hear significant improvements in purity, naturalness and transparency. 

I've spoken to two other guys who high-pass their Omegas the same way w/ sub (using 100 Hz and 70 Hz), and they also hear the same non-subtle improvements.

Apart from the change in your LF response, I'm surprised you didn't hear this improvement over the entire range.  Maybe using a value greater than 50Hz will free up the Omega driver even more and allow it to play with greater ease / finesse?

PS:   From your description, it sounds like your mid bass is too light.  Not surprising, given your room size.  I'd try raising your sub's crossover point......maybe even as high as 150 - 200.   If sub plays cleanly enough that high you should get more muscle and fullness without mucking up the Omega sound.