Speaker to Wall Bass Coupling Concepts

[Mr. Blorry]

OK. I'm pretty much stumped. Maybe you guys can help. I'm using Heresys as surrounds, and they're upright on shelves six feet off the floor. I have eight foot ceilings, and they're just two inches or so from the top. Per HornEd's suggestion, I inverted them to bring the highs closer to the listening level. (Thanks Ed!) My problem is that I have too much "boom" from the speakers. I primarily use it as a five speaker stereo setup, with KLF 30s as fronts, and KLF C-7 center, and the result is awesome! I am quite impressed, with the exception that the Heresys are providing too much bass!

My question is this: I know that the low frequencies couple with the walls to further extend the bass, but how does one determine the parameters of the extension? I can only pull them away from the wall but so much; after that, it's fiddling with the juxtaposition to find the best combination. If I were to cram the speaker all the way against the wall, would I reduce bass coupling? I know that pulling them away from the wall reduces this phenomenon, but will the reverse work as well? Unfortunately my amp doesn't have tone controls for the surround speakers alone; it is shared with the other three channels, else I would just bring the bass down a bit. I'm guessing that the bass coupling is furthered by the ceiling as well?!?

Does this make any sense? I hope so.

[Kevin S]

If you did not have too much bass prior to inverting the speakers, put them back in their original position. Since the surround speakers are supposed to be positioned so that they are difficult to localize, your original concern about having the tweeters too high and the sound bouncing off the ceiling is probably the lesser of the two evils. This ceiling bounce will serve to diffuse the sound a bit. Also, after switching the speakers back, place something about an inch or so tall under the bottom rear of the speaker to tilt them down somewhat. If your listening position is a reasonable distance from the rear speakers, you will be surprided at how much a difference a one or two inch tilt will make in the sound at the listening position. I hope this helps.

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L/C/R: Klipsch Heresy II

Surround: Klipsch RS-3

Subwoofers: 2 HSU-VTF-2

Pre/Pro/Tuner: McIntosh MX-132

AMP: McIntosh MC-7205

DVD: McIntosh MVP-831

CD Transport: Pioneer PD-F908 100 Disc Changer

Turntable: Denon DP-72L

Cassette: Nakamichi BX-1

T.V. : Mitsubishi 55905

HDTV: RCA DTC-100

Surge Protector: Monster Power HTS-5000

[HornEd]

Mr. Blorry, Kevin S. makes an excellent point on the bass issue. When I spoke of inverting the speakers, I did that in the context that the tweeter horn be just above the level of someone's head while seated in the sweetspot. I did not realize your rear speakers would be that close to the ceiling. My guess is that you are getting added bass reinforcement from the ceiling as well as the walls. I too have experimented with placing similar speakers on wall mounted shelves and turned the speakers on the side to avoid the problem... but they were high-end non-Klipsch speakers and, therefore, I did not have a "horn-aiming" problem. In this shelf mount arrangement on the rear wall, I had the L&R surrounds in the corners and the rear center in the middle. BTW, I used pieces of Dynamat to isolate the speakers and decrease resonation of the shelves and also tipped them to reduce the effect of the ceiling over reinforcing the bass.

When I switched to an all Klipsch horn-loaded audio environment, I eventually abandoned the custom shelving and went with floor mounted KLF 30's on approx. 10" high masonry stands for the side/surrounds and rear effects speakers. The side/surrounds are mounted against the side walls (facing one another as in the Audio Essentials subwoofer location example) and a foot or two behind the target LazyBoys in the sweetspot. The rear effects KLF 30 is centered against the rear wall. I will probably move the Twin SVS CS-Ultras against the right rear corner as this is the only "ideal bass" corner in my HT room, at least as an experiment. The current location in the front sound wall is already producing near reference level results.

Have you set your rear speaker array to SMALL and allowed your sub to carry the "non-directional" bass freight? That may serve to reduce the low bass bouncing of the ceiling... which is the probable culprit in your case.

One last note of an issue discussed elsewhere at length. The assignment of your rear speaker array differs with source material and your rig's config. Of course, without a 6.1 provision (straight or matrixed), the rear effects speaker falls silent. IMHO, the side/surrounds work better as full-range speakers for 5.1 (and above) source material... since most audio engineers now blend their sound mix as if their were five identical speakers as LMain, RMain,FCenter, LSide & RSide. They create the diffuse illusion as needed... and pop the specific rear surprise sounds... anticipating a discretely fed loudspeaker will be doing the job.

The diffuse sound enhanced by specialty speakers is a throwback to earlier sound conventions... so if you are locked into getting the most out of ProLogic (and before!) era source and/or equipment, get a WDST speaker and make the best out of it. Frankly, providing you have enough width to your listening area, the nature of source programming on older DVD's and videotapes comes out of properly placed KLF 30's quite well. That's why you find so much HT satisfaction with Klipsch connoisseurs with multiple Heritage class speakers in their 5.0 (and above) configurations.

Yes, Mr. Blorry, I am biased... but I came by my Klipsch/SVS bias the hard way... I kept tweaking until I found myself in this position. And, I shall keep tweaking as long as I have the strength and resources to do so. I am reminded of a full page Playboy cartoon decades ago that depicted a hall full of worshippers in togas regaling the letter "N" on pedestals scattered about and a newcomer strolling with a cult member. The caption was, "Is Nothing sacred around here?" When it is your ears making the determination, when it comes to sound, nothing is! HornEd

PS: Somehow the "ear-oriented" Smiley collection is somewhat narrow in its ability to relate the intended aspect... but it's not my fault!

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"Where Legends Live! Klipsch Powered HT"

FOREGROUND SOUND STAGE:

KLF 30 Center, KLF 30 Mains, KLF 10 Front Effects

BACKGROUND SOUND STAGE:

KLF 30 L&R Side/Surrounds, KLF 30 Rear Effects

LARGE MOUTH BASS:

Twin SVS CS-Ultra sub with Samson Megawatt Amp

SPEAKER SUPPORT SYSTEMS:

Mitsubishi RPHD1080i 65", Yamaha RX-V3000 Receiver

and such... Tweakin' On!

2-Channel Music Respite Room ala Cornwall under construction...

[Ray Garrison]

Mr. Blorry,

Couple of thoughts. If the high placement is otherwise working out well for you, and you'd like to leave the Heresys there if you can fix the bass problem, then:

1) how close to the SIDE walls are the speakers now? If you are getting reinforcement from the wall they are against, the ceiling AND the side walls, moving them further away from the side walls will reduce the bass a bit.

2) If you're comfortable opening up the speakers and twiddling, you'll find that putting some fiberglass or cotton batting inside the cabinets will dampen the bass. I'd give a call to Trey at Klipsch (poor guy, this board probably generates a gazillion calls a week to him...) and ask him what he things of this idea.

3) Trick used by VMPS... you can take a small length of the rope caulk sold at hardware stores (Mortite, I think, is the most popular brand) and stick it on the outside of the woofer cone by wrapping a short length of it around the dust cap. This will alter the bass response of the speaker, in general extending the response deeper into the bass while reducing the output level, though other effects might occur that screw up the sound. It is easily reverseable - the stuff is tacky, but won't damage the cone if you stick it on then pull it off if it doesn't help. Might help. Can't hurt.

4) You can make some cheap bass traps that work similar to the ASC TubeTrap products by filling some cardboard boxes with crumpled up newspaper and placing them in the corner. Requires some trial and error to get the right amount of damping, and of course you've got boxes stuffed with newspaper sitting in the corners of your room, but depending upon the acoustics and the dreaded Spousal Acceptance Factor it might help a lot. Saw an article about this someplace on the web, don't remember where, try Google if you're interested.

Ray

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Music is art

Audio is engineering

[HornEd]

As usual, Ray, the Dean of Oxford (CT), augers in on target! One additional thought, would it be possible to lower your speaker shelves some? That should help the bass and better orient the high's with the vertical aspect of your sweetspot. HornEd

[Mr. Blorry]

Thanks guys, for the advice. I've gone ahead and re-inverted the speakers back to their normal position. It looked a little silly (perhaps only to me, or another Klipsch aficionado like yourselves), but while the speakers were inverted the Klipsch logo was upside down! Mr. Cool, I just thought I'd flip flop the grille--NOT! Didn't realize Heresy Ones have the fiberboard beneath the grille cloth, and custom cut-outs for the three speakers. Crap! Ok, they're back to normal. Good. At least I'm not looking at "hcspilK" anymore!

Ed, I can't move the speakers down at all; in fact, they're as low as possible now! If they were any lower, I'd whang my head walking from the living room into the hallway! I've pretty much turned them to face each other, and the bass is mostly reduced. Ed, I also have a discrete 5 channel amp, so for sure I'm going to leave the Heresys on full range surrounds--I didn't spend $450 so that they could sound like radio shack whizzer cone crap! That's basically what I upgraded from!

Ray, thanks for the input. I may have to give Trey a call concerning adding insulation inside the cabinets--I have no qualms doing that--unless someone else out there has done this recently??? BobG or someone else want to stick their 2¢ in?

This message has been edited by Mr. Blorry on 07-24-2001 at 05:57 PM

[Mr. Blorry]

Kevin-

I didn't offer my thanks with the earlier post, but I have tried your suggestion as well, and you were quite right! After reverting them to the normal position, I angled them downward, and what a difference! The problem with myself is that I don't allow enough time to evaluate a positional change before I'm up and changing it again. This modification has been in place for almost an entire day and I'm still impressed! I think I'm close to leaving them alone!

Thanks again to all you guys--

[Kevin S]

Well I'm glad the change worked. But don't try to kid yourself into thinking your close to leaving anything alone!

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L/C/R: Klipsch Heresy II

Surround: Klipsch RS-3

Subwoofers: 2 HSU-VTF-2

Pre/Pro/Tuner: McIntosh MX-132

AMP: McIntosh MC-7205

DVD: McIntosh MVP-831

CD Transport: Pioneer PD-F908 100 Disc Changer

Turntable: Denon DP-72L

Cassette: Nakamichi BX-1

T.V. : Mitsubishi 55905

HDTV: RCA DTC-100

Surge Protector: Monster Power HTS-5000

[WMcD]

So, Mr. B,

For the benefit of others, what do think the problem was.

Do you think that lack of aiming the horns to the listening position gave the impression of too much bass, but it was actually too little treble? Maybe a bit of both, and the return to the orginal position cut the bass enchancement?

I'm sure the question will come up again.

Your thoughts would be enlightening to all.

Nice call, Kevin S.

Gil

[Mr. Blorry]

Kevin

You're absolutely right! I will prolly never be satisfied; hence the nature of the hobby! I still have a fair amount of "boom" and I'm guessing it's just below 250 hz or so. Does that sound about right? No, I don't have any measuring instruments; one of these days I probably will.

Sorry Gil, I can't give everyone a definitive answer, except that the intermingling of the smallest Heritage with the grandest Legend seems to be a nice fit, despite most folks opinions to the contrary. Could it be that I've convinced myself of this simply because I have spent so much money? Yeah, I'm sure that's part of it, but none of this would be an issue if Klipsch had offered an bookshelf Legend speaker. For some reason, they dropped their only Legend surround, and neither the Synergy nor the Reference surrounds can hang with the KLF 30s! I've auditioned all of them. Perhaps I should have auditioned Ref bookshelf, but these Heresy Ones were calling my name. Of course, my dealer also had matching K-Horns and a Belle too! Seems that the previous owner had moved into a smaller palace, and the WAF was unbearable, even to the point of ultimatum. "It's either ME, or your stupid speakers!" Hmm... Tough choice. I may have opted for the latter!

It's a shame I couldn't afford all the speakers; I don't have a WAF to deal with.

Anyway, back to my dilemma. I think my original solution may be the best, although it was too rich for my blood at the time. I found a company that makes tilt and swivel television brackets for thirteen inch TVs that match up with the Heresys perfectly! The bottom plate is about an inch smaller than the speaker, and there's plenty of room behind. They can tilt downward, and swivel 180° There's also a handy-dandy strap to keep the 55 pound bad boys in place! They're about $45 a piece, but 90 clams was too much after I had just bought the speakers, so maybe in a few weeks, because my alternate cheapo solution was buying plywood, brackets and stuff from the hardware store. It looks cheesy, but the whole thing cost me $20! There's a GAF looming though (girlfriend acceptance factor), so I may need to get the brackets soon.

The current setup is liveable except with a few old bass-heavy recordings (James Brown's "Cold Sweat" bass line boom is quite annoying, which is sad because the bass line is great). So, it's a temporary solution. I think the TV brackets will be great, except that once they're up, moving them will be a major hassle, and several more holes in the wall.

This message has been edited by Mr. Blorry on 07-27-2001 at 10:44 PM