Khorn Bass

[edwinr]

Even pulled out from their corners, my Klipschorns have a bass impact that many other speakers need subwoofers for. Once properly sealed into their corners, the Khorns deliver a bass that shakes the windows. I concede that certain rooms may not deliver the same bass I get from my double brick construction walls. In other rooms the bass may not be so impressive. But you can say the same for other top end loud speakers. Bass is hard to get right, you've either got too much, too little, or too much or too little in the wrong places. It also depends on what you're listening too. Many record producers dial in extra bass to suit less full range loud speakers. The result is less than pleasant on my Klipschorns. But overall I wouldn't be so harsh as to denigrate the Klipschorn bass performance unless we wanted to deliberately stir the pot!

[BerndH]

Elimination and reinforcement of bass at different room position is not my biggest problem, because ususally i sit during listening.

There is another thing that gets on my nerves. In the frequency range somewhere between 100 to 150 Hz seems to be a strong resonance. When the bass player holds a bass note at this frequency a little bit longer, it booms. Then it sounds like an organ pipe.

Anyone else with this problem?

Bernd

[Rudy81]

Bernd:

When I ran the low frequency sweep, I was sitting in the sweet spot. This particular room has terrible proportions and depending on frequency, you can easily hear the nulls and reinforcements. They are readily apparent without moving around. Of course, different room locations will see different results.

[Rudy81]

I started this thread four years ago when I first got my Khorns. I complained about the lack of bass response when compared to my La Scalas or Belles. All the advice pointed to my inability to properly seal the bass bins. That led me on a journey to build some pretty serious false corners, add pipe insulation to the tail board and sides of the bottom part of the top hat. Overall, I had become happy with the sound reproduction, although I was never blown away with the bass.

I recently had a chance to audition a pair of Palladium flagship speakers. I was stunned at the performance of that speaker, the bass in particular. I felt my Khorns could do well against that speaker, but not in the bass department. That experience with the Palladium set me on a mission to figure out what was wrong with my speakers. I figured the Palladium couldn't be that much better than the legendary Khorns......right?

In my search I found this thread http://forums.klipsch.com/forums/t/37447.aspx dealing with issues related to having your Khorns sitting on carpet!!!! Well, I had constructed my false corners with carpet at the bottom purely to match the room. I wondered if I removing the carpet could in fact make any difference at all.

I removed the carpet, finished the bottom of the false corner (3/4" plywood) with stick on flooring. I then removed the metal studs from the bottom of the bass bin and added the grippers suggested by HDBRbuilder. It was not easy moving the Khorns back into the corners, but I got help and was able to wedge them in properly.

Tonight I finished my third night of auditioning my NEW Khorns. My apologies to PWK for doubting his brilliance! I cannot put into words the amazing difference this minor change made. The bass will now blow away my La Scalas, Belle's or Cornwalls. Yes, I have most of those and sold my Belles a while back. I suspect that these properly set up Khorns will compete just fine with the new Palladiums.

The bass is deep, dynamic, and depending on the recording, can hit you like a baseball bat to the chest. I feel like such an idiot! I had no idea these speakers were capable of shaking the room like that.

If your speakers are sitting on carpet, PLEASE set them on a solid surface, remove the metal studs, add the grippers and make sure the tail board is properly sealed. Your neighbors will hate you.

[Mallette]

Grippers?

Dave

[Rudy81]

Grippers?

Dave

Yep, HDBRbuilder suggested removal of the metal glides and adding rubber 'grippers' (that's what they are called) from Wal-Mart. $2.79 for 8 large grippers. They do make it nearly impossible to move the complete Khorn by sliding it along a hard floor. Amazing difference for such a cheap mod.

[soundbound]

Have you tried the bass bins with bare bottoms? No metal glides or rubber grippers to see how that sounds for you? It's a free mod for you to try. If you do try it, let us know what you hear.

[Rudy81]

No, I did not try just the bare bottom. I would guess the bare bottom would not create nearly the friction the grippers do. Thus, not coupling the bin mass as much as a bin with grippers.

[Mallette]

OK, I'm in. The carpet is coming out of the music room at some point anyway. I'll just cut around them in place, the pull the piece out, remove the metal widgets and add the gripsters.

Cheap thrills.

I presume there is a reason you can't just put the grippers over the metal widgets?

Frankly, I don't recall any metal thingies on my bass bin...

Dave

[PrestonTom]

An alternative that I tried was to squeeze and tuck some 3/8" foam (closed cell) along the perimeter of the cabinet and the floor. I think this also helped with the low end response. Although the more time you spend on these tweaks, the more likely you are to convince yourself of the improvement.

This idea may be an alternative for folks who are concerned about scratching hardwood floors etc.

-Tom

[Rudy81]

Dave: please let us know the results. Your bass bins should have 3 metal glides. I removed them and put 8 grippers on each bass bin. It will make the bins difficult to move on a hard surface, like a wood floor. Also, make sure your bin has a near perfect seal between the tailboard and the corner. I ended up using pipe insulation to get the best possible seal. One technique I used to visually check the seal is to put the only the bass bin in the corner. Then, aim a flashlight down the open corner behind the tailboard and look at the vertical edges of the seal from the front. If I see any light, the seal is not good enough. I look forward to your report.

Tom: I try to be very careful with phychoacoustic 'improvements'. I generally give any changes several listening periods over several days to ensure the change is real vs. a mental expectation of change. In this particular case, the change is so visceral, so dynamic and so obvious, it is not in my mind. I used to complain that the bass from a set of La Scalas could be felt as a thump in your chest. My Khorns seemed to be unable to do that, which I was told was part of the Khorn's 'different' more room encompassing bass. Well, b.s., these 'new' Khorns are shanking the room, thumping my chest and outperform the La Scalas in every way. Frankly I just don't have the vocabulary to express just how large the change has been with this $7 tweak.

[Rudy81]

An alternative that I tried was to squeeze and tuck some 3/8" foam (closed cell) along the perimeter of the cabinet and the floor. I think this also helped with the low end response. Although the more time you spend on these tweaks, the more likely you are to convince yourself of the improvement.

This idea may be an alternative for folks who are concerned about scratching hardwood floors etc.

-Tom

Tom: Read the long reply on page 2 of this thread http://forums.klipsch.com/forums/t/37447.aspx?PageIndex=2 by HDBRbuilder relating the use of silicone caulk under the bass bin. I would guess the effect of the foam under the bin would have a similar effect and also improve the response. The whole idea is to mass couple the bass bin to the floor to ensure the cabinet does not move at all when the woofer is doing it's work, thus clearing up the frequency response etc. I KNOW this works. I have changed my crossovers to ALK universals, changed the K77's to Crites CT-125's and this change is by far more of an inprovement in system response. That is not to say I would be willing to give up the ALK's or CT-125's. I will soon also be trying Bob's new cast frame woofers. As far as tweaks, the carpet removal and gripper addition has made the biggest change!

[Chris A]

My listening rooms are not carpeted: the main listening room's RT60 (reverberation time) above about 200 Hz is still about 0.3-0.4 (which is good), while the RT60 below this point is about 2-3x higher. I believe that the rise in RT60 at low frequencies is primarily what you are listening to when you remove the carpet from the false corner base. I really don't think that the "grippers" will affect the sound like removing the carpet, but the grippers will certainly make it more "stable" on the floor . Removing the room's carpet (if any) would increase the effect. This all assumes that your listening room is 14+ feet across and fairly deep (i.e., greater than 14 feet). Having a fairly high ceiling is a big deal, too.

I notice that my Jub bass bins in my main room are really impressive during movies with the LFE channel piped through them, especially with a small amount of EQ shelf filter rise below about 100 Hz (~4 db boost at 31 Hz). Try it on your KHorns...I would bet that you'll never go back to "flat".

Chris

[Rudy81]

Chris: I don't have enough knowledge to understand why the big difference when removing the carpet from the base of my false corner. The entire room is carpeted, walls have mid and high frequency treatments, dimensions are 20' wide, 27' long and 9' ceiling. Sweet spot chair is at 14' from center. All I know is that the change in bass performance has been substantial. Later this week I may take a shot at creating a 'top' section for the bass bin, thus closing the mouth of the folded horn like a Jub has. I am very curious to see what difference that will make.

[Chris A]

The biggest place to affect lf damping in home environments is in the corners - that is why most people use corner bass traps instead of something along a wall, etc. Getting close the source of sound (i.e., the KHorn) with damping has the biggest effect. I used to have bass traps over my Jub 402 horns, but no longer. The bass traps in the same corners as the speaker had too much effect.

You might notice that the KHorn bass output will actually decrease as you further enclose the bass bin - this is apparently what happened to the 60th Ann. KHorns - in which the balancing networks had to be changed to increase lf when the sides of the bass bin were sealed off. Strange, huh?

Chris

[Rudy81]

Chris: I have bass traps on the room corners opposite the Khorns....mostly to reduce room size standing waves. The room was very live when I started, so I added absorption to the side walls to reduce high freq. echoes. I get a much more defined sound with the side panels in place. Imaging is much more precise as well.

I had not heard the 60th anniversary Khorns had experienced a reduction in bass by enclosing the back. Enclosing the backs must somehow have reduced the 'size' of the folded horn. I know some on the forum have made their own backs and wonder if their bass was affected. I just hate to drill or make permanent changes to my cabinets, so have resisted doing that.

I will try to add a plywood piece to my false corner that will 'finish' the top of the bass bin, but without damaging the cabinets. If it works, I'll post impressions and pictures.

[Chris A]

Chris: I have bass traps on the room corners opposite the Khorns....mostly to reduce room size standing waves. The room was very live when I started, so I added absorption to the side walls to reduce high freq. echoes. I get a much more defined sound with the side panels in place. Imaging is much more precise as well.

Have you thought about ceiling bounce (especially 8' ceiling or lower)? This is one of the biggest issues with KHorns, etc. Pianos and female vocals are larger than life, among other things.

I had not heard the 60th anniversary Khorns had experienced a reduction in bass by enclosing the back...

This information was offered by a Klipsch employee that took credit for the change to the 60th Ann. version...

Chris

[Rudy81]

I have a 9' ceiling, but yes, I have thought about treating the ceiling just in front of the Khorns at the 'reflection' point from my seat. I just haven't gotten around to doing that treatment.