bass help for 2Bs

leftwinger57

I was listening to some live streaming Grateful Dead running from my computer to my Yamaha rx-665 but then through my Dynaco pre/amp. It's a bit convoluted but it's what I do. This time I noticed Phil Lesh's bass was thundering way more than usual more than likely a Wall Of Sound show. Reason was I did not audio mute my h/t system with my sub included as I usually do. I dropped the h/t out of the equation and my 2Bs just sounded like the bass just wasn't as it should be for a fully modded set compared against the stand alone sub. Is my sub, a powered 8" Klipsch all that and goes much deeper or is am I missing something on the Polks ?
Fully modded w/ the exception of the coil inductors I think there called.

heiney9

Many times the output of subs is too high, giving the impression there is more bass because it's playing louder. How do you calibrate the sub so it plays at the same level of output as the 2B's?

Calibration is a very fine balance and a sub playing even just 2dB higher could make it seem like the sub is putting out more bass than the 2B's.

Of course we know nothing about how you have them set-up and located.

H9

Nightfall

How close are the SDAs to the rear wall? Check phase?

amb426amb1

The large SDA inductors made the biggest improvement is bass for me when modifying a pair of 2.3tl's. Used the super Q iron core units with very good results. That said, I think you will always hear a significant shift in two channel audio when adding a power sub. Guess it's all about preference but I only use a powered sub in HT listening and prefer music without.

heiney9

SDA's don't need a sub for music if they are set up properly and driven properly.

H9

leftwinger57

H,I agree and never thought the 2Bs should even need any help and should always win out but boy I was wrong, The sub re positioned and connected by a double braided coax and compression fittings got really dialed in. Also added in the mix which I just got last month was the Boss ground loop insolater which completely took the annoying minor hum I was getting from the run of siamese coax, about a 35' run. My 2Bs are 18'' off the front wall and are more opened up sound stage


stage wise because of the open Stanus rack. Volume at the time for the H/T was pretty high but not anywhere near my clipping level. I'll show some pics.My powered sub was never intended to work w/ the 2-chl systm it just happened today when I forgot to mute the Klipschs. Originally xoverd at 80hz and when moved increased both phase and vloume. The sub is under the lamp table to my left.

amb426amb1

If I understand correctly you have 2b's 18 inches off wall? They really need to be more like 5-7 niches for your bass to be at its Best. Would really help to couple speakers to hard wood floor by way of spikes.

pitdogg2

amb426amb1 wrote: »

If I understand correctly you have 2b's 18 inches off wall? They really need to be more like 5-7 niches for your bass to be at its Best. Would really help to couple speakers to hard wood floor by way of spikes.

Yes ^^^^

Nightfall

Mine are 17.5" from the rear wall (otherwise they'd be behind the plane of my Salamander and TV) and I get incredible bass if the song dictates it.

leftwinger57

Mine were originally way more deeper/closer to the the front wall. I then moved them up when my rack changed. I thought we took a poll a few months/years ago about spacing from the front wall. Most iirc were 12'' or over and in my case I have forced hot water heater pans that extend out of that particular wall and then I needed more space to open them up on the sides. Believe me, I've seen a lot worse SDA set-ups than mine (way tighter spreads,reflective crap or no treatments in the room,or not modded) and I still don't get all out of them because of the 3 foot side wall clearance deal. Spikes I tried doing alone, not the thing to do w/ 80lb speakers and tight spacing and 2 blown rotator cuffs. They were all drilled and all the sleeves are still in them but for now covered up by bigger button sliders. When some company comes over I can revisit spiking and placing them on the protection discs. Maybe it was just that particular show, volume of the 2chll and adding in the powered sub at a higher level not usually on just got to me.

westmassguy

Lew, as @heiney9 pointed out, the sub was adding additional bass, most likely on top of what the 2Bs were already producing. If your setup didn't roll off the 2Bs at the same frequency the subwoofer is set for, the bass will be disproportionally loud.
We can do the Sub Bass Drive Inductors at some point if you want. All 3rd, 4th and 5th generation SDAs, with equal number or stereo and dimensional drivers, will benefit greatly from the low resistance Inductors. The caveat of course, is the 2Bs will no longer be 6 ohm, they'll be 4 ohm nominal. Your Adcom will handle them easily though.
BTW, the 8" sub is more than likely not going any deeper than the 2Bs do by themselves.

leftwinger57

Dave, as usual that makes the most sense. Again I started to get over thinking nutty about something I could control or not. I'm not displeased w/ the the bass throw as my weeping appears but this just took me by surprise. Thanks...

BTW the M7s sound terrific after the amount of hours I've put into them.

westmassguy

Glad to hear Lew.
Like I said, if at some point in the future, you want to do the Inductors, we'll work something out as we always do.

F1nut

I thought we took a poll a few months/years ago about spacing from the front wall. Most iirc were 12'' or over

I don't know about any poll on the matter, but 5 to 6 inches is the norm. 12" is too far away.

I just listened to a pair of modded 2BTL's driven by a he-man Musical Fidelity integrated amp the other day. The speakers were 5" off the back wall and spiked. The bass was amazing.

leftwinger57

Jesse going back a few inches is no problem but then my spacing on the open sides issue would get worse and be more closed in. Like I said before I can also revisit spiking but w/ help, not for me to even try positioning alone. I'll just tear up my floors.

machone

What you need is a LPSJMT.
Low-Profile-Speaker-Jack-Mover-Thing

leftwinger57

What the hell is that.. I don't have 900lb Von Schweikert monster speakers. I just need another hand or 2 because of the tightness of spacing and the loss of strength due to operations. I picked on these speakers because I did see these things at a dude's house selling C/L stuff. I'm not buying anything else especially for a 1or 2 time use thing. Rumor has it P-Man might be making a summer appearance at my house so maybe then if he comes I'll consider doing it, which after all is said and done 1 still have a nice set of sounding speakers.
Machone, I am interested since you did do the bass inductor coils what difference or how much of a difference in bass response is there ? Some what noticeable or night and day no comparison noticeable ? I just realized we have 2 different models but let me know.


http://www.vonschweikert.com/#!vr-9se-mkii/xb2a1

machone

Just kidding about the mover thing. It would be nice though. I got my spikes today but I am not installing them because I am remodeling the room and constantly need to move things around.
I rebuilt the xovers at the same time I changed the inductors so I cannot comment.

lawdogg

What size is your room?

machone

18.5 ft x 21 ft x 9.5 ft

leftwinger57

Don't know exactly who your referring to here. So my living room is 18'x15'x10' ceiling. It does open to my dinning room and there is a hall leading away so it's not a tight buttoned up room per se'. I do have rugs and a puffy couch so reflections are not a problem.