Anyone added multiple subs to 2 channel setup?

[amheck]

I emailed Rythmik and described my room and situation and they didn't think they have anything that will work.  I was a little shocked.

 

They have their $1500 15" F15HP that does have a high level input option but the guy that responded to me didn't think 2 of these would be enough in my room.

 

Someone on AVS posted that they use some REL subs with separate music and HT systems.  They have RCA and high level inputs hooked up at the same time.  I liked that idea and it would really simplify just to have 2 nice subs total, but then someone else chimed in that they thought it'd be a bad idea to do that.

 

It's never simple....I have no idea which way to go.

[Quad Khorns]

I have 8-18" subs and 2-12" subs in one system, each driven with massive output pro power amps. That is 5 per channel.

 

Sounds crazy, but there is such a uniform response and coverage of the space, there are no weak spots anywhere in the room (32' x 23'). And no boost equalization is needed to get nice tight bass - no boominess anywhere, delivers both punch and deep low frequencies as needed. And gain is set very low and still achieve the desired output.

 

I probably can use less and get similar results, but I never sell anything, so hey why not use it?

[Islander]

2 subs are definitely the way to go.  Here’s my story:  first, the main speakers are JubScala IIs (La Scala IIs modded to 2-way bi-amped with K402 Jubilee tweeters).  For years I had a 400 watt 10” Paradigm sub that was okay, but it didn’t go all that deep (23 Hz spec).  In 2020, I bought a new Paradigm 850 watt 10” aluminum-bodied sub with an 18Hz spec.  Both subs have sealed front-firing housings.

 

I could immediately hear the fuller depth and power, but after a while it seemed that my usual Net Radio station had really turned up the bass.  After checking around the room, it became apparent that there was a severe (+20 dB) bass peak in front of the sofa.  I had planned on getting a second sub anyway, so I did that, and the bass peak was gone.  The bass response is now acceptably even throughout the room.

 

With the Yamaha RX-A2060 AVR, there are two Sub Outs, so that was easy.  Just so you know, in many cases the subwoofer info in the music is mono, like in a 5.1 mix, so going to trouble to separate the sub channels will likely make no difference.  I think both of my Sub Outs are on the same channel.

 

After a few months, I noticed that the bass seemed a bit overpowering sometimes, which surprised me, because I’d carefully balanced the levels of all the speakers, including the subs, using a Radio Shack SPL.  Then I remembered that I had not accounted for the effect of adding a second sub on the total volume in the room.  I think the second sub adds 6 dB, so I lowered the level on each sub by 2.5 dB, and now the sub level seems right.

 

So that’s my situation.  I should add that my listening/living room is 18’ x 19’ with an 8’ ceiling.  It opens on one side to the hallways and dining room, so calculating its total volume is a bit tricky.  I don’t normally listen at high volume, mostly 60-80 dB, unless I’m showing off the system for a few minutes.  1700 watts of  subwoofage seems fine for my application.  As the saying goes, YMMV, and I believe that it’s good to have more power than necessary, because you can always turn it down, but if you don’t have enough power, you’re out of luck.

 

Last thing:  the La Scalas, OG or II model, start to roll off on the bottom end at 100 Hz, and by 50 Hz very little is happening.  Accordingly, I set the subs’ hi-cut at 110 Hz or so, to allow for the subs’ top-end rolloff.  That way, there’s no dip at the crossover point, as can happen if you set your subs’ to cut off at the speakers’ claimed low-end limit.  To be sure of even bass response, you have to check every 10 Hz or so, from 140-150 or so on down to the subs’ actual bottom limit.  I drew up a chart with pen and ruler, and then photocopied it to have enough to do quite a few test runs, in order to be able to set the subs for the most even bass response.  You don’t have to do the testing at high volume.  65-70 dB is loud enough if you’re in a very quiet room, as you should be.

 

Good luck with your quest for great full-range sound, and happy listening!

[Islander]

If you can do it, I’d be looking at a different amplifier, one with Sub Outs.  You don’t need to have two systems for good sound. A multi-channel system can work fine when playing 2-channel music.  Just turn off the unneeded channels if necessary, or just play your music straight.  The speakers that aren’t getting any signals won’t have any effect on the two speakers that are working.

 

BTW, the combination of La Scala IIs and good subs makes for some of the best sound in the whole Heritage line.  Of course, the Heritage Jubilees are in a class of their own, but a system of LS2s and good subs gives Klipschorns a run for their money.

[amheck]

yeah, I guess I just need to step back and think what I want.  I have so many options spinning around in my head its becoming overwhelming and stressful.  It bothers me not having a set plan and definite path forward.

 

You are right, my original "HT" system (Onkyo RZ50, Klipsch RF-7iii, RC-64iii and RP-600m) would probably play 2 channel music just fine.  There are pure audio and direct modes you can play around with to take the AVR processing out the mix if you really want.

 

But I had my heart set on tubes for the 2 channel music.  Will I hear a difference?  Very well I may not but I REALLY wanted to have a 2 channel system with a nice set of tubes to look at.

 

One option, I suppose, I sell the Klipsch reference premiere speakers and just go with Heritage for all of the speakers (LS II for the main and perhaps heresy for center and rears?) and then if I keep the AVR, I can go with a couple nice subs and call it a day with just 1 system.

 

Maybe its the 2nd separate music system that's causing the issue.  Maybe its the tube amp with no sub out.  Maybe its both, I'm not exactly sure at this point.

 

Meanwhile, the Willsenton R300 int amp was delivered yesterday and is just sitting in the box.  Part that surprises me the most is that the tube amp seems to be the issue as many are pointing out.  I thought these had been around for so long I figured there was no issue at all buying something without bass management or rca out

[billybob]

Have you considered an option for biamping the tube to hf and the lf with the Onkyo?

Since you have no subwoofer now, guess your rf-7s are set to large for bass ht.

I see the Onkyo has dual mono..

Both your speaker front pairs are bi-ampable.

Any subwoofer practically will give you a taste of what you may or are missing in the bass dept.

Comparability and compatibility need resolved.

Yes, a step back to consider.

Exercising your options and discovering them. Slow will get there.

 If you hook the tube amp to the LS 2 for stereo, let us know how it sounds after burning in.

Especially the bass.

Nice reviews on the amp.

 

[Tom05]

On 2/6/2023 at 8:26 AM, amheck said:

Hi all, I have a Willsenton R300 integrated amp coming today and was reading up on adding subs.  As there are no sub outs on this amp (but multiple speaker outs of varying resistance), I think I would have to rely on high level line connections.

 

I think hooking up 1 sub is pretty straightforward but I have always read that multiple subs will help even out the bass response in the room.

 

1. The subs I am looking at (HSU ULS15 or Rythmik F15HP) only have line level in, so I think you need to run a connection from the amp to the speaker and then another run from the amp to the sub.  So the crossover on the sub takes care of the sub output, but then the speakers are getting full range.  Is that an issue?  Usually, I'd think you'd have a high pass filter, but without a line level out of the sub, I'm not exactly sure if this is a concern or not.

 

2. On another forum, it was suggested to hook up the left speaker outs to the left sub and the right speaker out to the right sub, but I'm concerned this is not the proper way to integrate multiple subs into a 2 channel setup.  I think you'd want both L and R to both subs but man, that's a lot of speaker wire out of our speaker outs on the amp.

You’re fine running a parallel high level signal to your sub amps . Your speakers will run full range and that’s a good thing with Lascala, its usually the best way to run them in my opinion. You can run your subs in stereo or mono , see if you prefer one over the other. As Shakeydeal said “Just let them roll off on their own . That’s good advice.

[amheck]

FWIW, I emailed HSU and asked them about their thoughts about using 2 subs, hooked up both to the HT and Music systems at the same time.  

 

one issue is that some AVR's sent out impedance on the RCA sub out even when they are off.  So if you were using the tube amp in the "music" system via high level inputs on the sub and the volume was low, you'd simple need to disconnect the RCA from the subs and everything should act normal.

 

Also would need to engage the sub crossover when listening via high level music system, but maybe turn off the crossover on the sub when in HT mode and let the AVR do its thing.

 

they also said dual VTF-15H might or might not be enough low end, depending on volume levels you listen to.

[amheck]

1 hour ago, billybob said:

Have you considered an option for biamping the tube to hf and the lf with the Onkyo?

Since you have no subwoofer now, guess your rf-7s are set to large for bass ht.

I see the Onkyo has dual mono..

Both your speaker front pairs are bi-ampable.

Any subwoofer practically will give you a taste of what you may or are missing in the bass dept.

Comparability and compatibility need resolved.

Yes, a step back to consider.

Exercising your options and discovering them. Slow will get there.

 If you hook the tube amp to the LS 2 for stereo, let us know how it sounds after burning in.

Especially the bass.

Nice reviews on the amp.

 

 

I haven't looked into bi-amping with the tube amp, although its only 8 W and my other amp is a 5x200 monolith, so probably not a good match for bi-amping.  But I did come across Home Theater bypass, and maybe a way to hook up the tube amp as a power amp out of the Onkyo.  But wondering if that's really complicating the issue way beyond what I should be.

[Shakeydeal]

I had a single VTF 15, but I sent it back for the dual uls 15s. If you value music over explosions and car crashes, it’s the way to go.