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I once bought a pair of very expensive speakers, based on what I read about them in a review.
The speakers were so un godly bright, I sold them, lost money.
The reviewer had them in a large, dead room, and sat a 15 feet away.
My room was small at the time, and I was real close to them.
A case in point is my Polk SRS 2's.
In a large room, I find them too dull for my tastes.
In a smaller room, they sound better, but the bass from the refrigerator sized Polk SRS 2B's just overwhelms my second room.
Answer ?
Sell them, or buy a new house ?
Hate to say goodbye to the incredible imaging the Polk SDA speakers are known for, but they got to go.
I have my JBL S 412 P's in my large room, and the B&W Matrix 801's in the smaller room.
I may even sell my 801's because my second room is tiny, and get some smaller stand mounts ?
The JBL S 412P's I just adore, and they work very well where they are at.
I am sure many have experienced similar stories about room/speaker interactions ?
IME, the room is everything!
Correct speaker/room matching is so very important.
Follow Ups:
I am amazed you prefer those JBL's over a set of B&W Matrix 801's
Personally I cant imagine the low budge JBL's with cheap xovers and
drivers to even come close to the B&Ws in any way shape manner or form.
To each his own
I still have my Matrix 801's, and listen to them every day!
I have the JBL's in my home theatre room.
I enjoy both speakers.
On well recorded material, the 801's are better.
The jbl's are more tolerant of some of the crap recordings I like.
Of why I got into DIY loudspeaker-building.
As you allude to---"one of" the most critical aspects of sound is the loudspeaker/room interaction. IMHO, it’s the MOST important aspect of the total sound.
In my experience, the best possible way to achieve "the absolute sound" in YOUR room---- is to design your OWN speakers that are matched to YOUR given room and YOUR given equipment. This way you can "tune" the speakers to be as bright, dull, bass heavy, bass light as you want! That is, as long as you know what you are doing.....
Yeah, Matt Polk (or whoever made them) made those speakers you have for what sounded best in HIS room at the time, with HIS equipment. How in God's name he expects that to transfer to the thousands of other systems and rooms out there using those speakers just makes me scratch my head! No knock on Polk (that's actually, along with PSB, B&W, Maggies and Paradigm, the brand names I recommend to all non-audio/family friends who want to walk into local stores and buy decent and inexpensive speakers around here), it’s the same with 99.7% other speaker manufacturer's too!
OK, I'm off my soap-box for the night.....
Regards,
Joel
When you listen nearfield, the first-arrival sound dominates the perceived tonal balance. When you listen farfield, the power response (summed omnidirectional response) dominates.
A step in the right direction, in my opinion, would be a speaker whose power response is very similar to its first-arrival response. I didn't say "on-axis response" because some manufacturers (yours truly included) recommend NOT aiming the speakers right smack at the listening position in the interest of minimizing the spectral discrepancy between the first-arrival and reverberant energy, thus making the tonal balance more consistent throughout the room.
Duke
Me being a dealer makes you leery?? It gets worse... I'm a manufacturer too.
The first time I heard a pair of LS3/5As, they were pulled out far away from all the walls in a really big room, with chairs set up about 7-8 feet away. I walked around the speakers --360 degrees-- and the sound stage never really went away, just got thinner, but the music sounded lovely.
Is that what you mean?
"What did the Romans ever do for us?"
Very interesting example you give!
The LS3/5a has very good power response, but at the expense of on-axis response. This is deliberate and in my opinion is the correct choice. You've no doubt heard of the "BBC Dip", a mild dip in the 3-4 kHz ballpark. This has been mis-understood to be a psychoacoustic compensation of some type. Instead, it corrects the power response by decreasing the tweeter's output in the region just above the crossover, where its radiation pattern is the widest.
What you heard when you walked around the LS3/5a was a combination of an unusually wide overall radiation pattern with unusually good power response.
Me being a dealer makes you leery?? It gets worse... I'm a manufacturer too.
Nt
"What did the Romans ever do for us?"
Sound Power is a measure of the acoustic output of a device - in the case of a loudspeaker it is usually given relative to 1 Watt of broadband (pink noise) band limited to the specified pass band of the loudspeaker. This way a satellite speaker would not be penalized by its inability to produce the lowest frequencies. The units (confusingly) are also given in dB - but with a reference level of one picowatt (10E-12).
Since, at least for home use, listening rooms are mostly somewhat reverberant, and virtually all reflected energy occurs before 80msec, the sound power determines the "loudness" of the speaker. Unlike the pressure sensitive specification (xdB @ 1 meter @ 1 Watt), the sound power specification for sensitivity does not penalize dipole, omnis, and line arrays, while equalizing the effect of horns, phased arrays and waveguide loudspeakers.
The standard xdB @ 1 meter @ 1 Watt is a valid measurement for drivers (measured on an infinite baffle) and Professional (PA) loudspeakers because the important aspect of the performance is the the pressure they can create - at the listeners seat in a free field - no reflections.
Sometime once the ability to measure the sound power of a loudspeaker is more available - some mfg do this already - it may become a common specification. A 1% (fairly efficient) loudspeaker would be rated at 100dB, where a common 0.1% efficient loudspeaker would have a 90dB rating.
Note, this measurement is very difficult to make above 5KHz requiring thousands of points. There are some very trick techniques B&K have developed to make this measurement - none of them cheap.
The "power response" is the summed omnidirectional response of the loudspeaker; that is, the combined total of its output in all directions. The on-axis response is the speaker's output in one direction only.
Me being a dealer makes you leery?? It gets worse... I'm a manufacturer too.
Edits: 12/17/09 12/17/09
I always wondered about the "dip". Some people point to it scornfully, but I find this speaker to be very well-integrated, better than most, and I don't actually hear the dip. It seems smooth in the cross over region to my ears.
"What did the Romans ever do for us?"
Floyd Toole. A speaker with an uneven power response is usually perceived worse than one with an uneven first arrival. This allows some omnis like Shahinian to sound much better than the direct sound measurement would indicate. A sound power measurement is a difficult measurement to make without a big reverberation room or a bagilian anechoic measurements or a two microphone intensity system like this...
Edits: 12/15/09 12/15/09 12/15/09
Okay, what is that thing... that two-microphone intensity system? I'd like to read up on it.
I'm always fascinated by speakers that sound better (or worse) than normal measurements say they should, as that's an indication that we have some ground still to cover regarding which measurements correlate best with subjective preference. The Shahinians are a superb example - apalling conventional measurements, but glorious sound.
I haven't read Toole's book, but I've read a lot of his papers. Actually I came to that conclusion via another route, back in the late 80's, but didn't know how to put it into practice until a few years ago. I wrote an article on the subject for SpeakerBuilder magazine in 1989 but it was rejected, and in retrospect I'm glad it was.
To get a handle on the power response, I now use a suite of time-gated off-axis measurements (something I couldn't have done twenty years ago). Takes a while, though. I virtually ignore the on-axis curve when doing crossover design, but still run it just so I can see how closely it tracks the off-axis curves.
In my opinion the two dominant factors in how a loudspeaker sounds are frequency response and radiation pattern, and I think they can be conceptually combined into frequency response across the 3-dimensional space the speaker radiates into. This can be approximated by a colorized polar map, which simultaneously displays frequency, angle, and intensity in one plane (usually the horizontal). Polar maps are occasionally seen in high-end prosound. The only home audio manufacturer who has published polar maps, to the best of my knowledge, is Earl Geddes.
In my experience when there's a big discrepancy between the conventional on-axis frequency response measurement and the subjective "sound" of a speaker, the explanation is most likely to lie in what's happening off-axis... as in the case of the Shahinians.
Duke
Me being a dealer makes you leery?? It gets worse... I'm a manufacturer too.
Hello Duke !
Do you recall all the design work you did on my dual subwoofers ?
I used your suggestions for an extended bass shelf alignment, and I have output down to 18 hz, actually I can still feel it at 14 hz.
But at 18 hz it is probably 3 db down, going by ear.
I have recently bewcome single again, and have parties at my home.
I have a 23 year old dancer coming over with her dancer friends(I am 55) and they want something to really SLAM, like they hear in the dance club!
The ceramic tile in my room supports dancing.
I want to raise the tuning Duke, for more PUNCH on dance music ?
I THINK you said to use 2 - 7 inch ports, 3 inch PVC in each sub ?
I have 2 ports in each sub now, around 18 inches long, tuned way low.
The drivers are the cadence wild beast 15 inch woofers, so perhaps you stored it ?
The boxes are around 8 cu ft, if I recall ?
I will keep the longer port tubes around, in case I dont like the boom boxes ?
But right now, I just want to party with my little 23 year old Dancer, and her bi sexual friends.
Call it a "mid life crisis" or whatever, I call it FUN !!!
Good to hear from you again Duke, and thank you again for all the great design work you did for me !!!
Chris
.
I had 2 x dual 18 push pull subs.......... Lots of pulse and pressure, but not slam (crossed at either 100hz@24db or 80hz@18db).
Slam was either a w-bin (7ft3 area of mouth, best kickdrum I've ever had) or 4 x 15" woofers (in additional to the subs).
What is funny is I ran a 15" as baffle step (with inductor only). At low volume hooking it up there was no audible difference, but the louder you got, the more the difference the extra 15" made (like old stone temple pilots).
That is the kick drum that hits you in the chest. That's the 100-200hz range.
It might be time to stop the "retail thing" and start doing the active crossover tri or quad amplifier.
Norman
Some good ideas Norman.
I have almost enough "kick" now, for my room, just want to raise box tuning, get a little more.
The Cadence Wild Beast 15 inch drivers have a pretty good amount of X Max, and I have enough power to take them there.
Honestly, even when the room is quivering from 20 hz tones, I still have x max left.
I hear what ya say about kick drums, my old Speaker Lab K corner horns did a great job up there.
I am using a rane electric crossover at 24 db per octave, with two pro sound amps driving the pair of subs.
I already have the new ports cut at 7 1/2 inches, just wait for my kids to come help me flip the subs over, to change the ports.
It MAY very well turn out to be a boom box, and so be it ?
As long as it goes boom where I want it to ?
Hmm, changing tuning from 20 to 30hz ?
That won't add slam at all, if anything you may have more sluggish bass.
I know that a 30hz tuning was much better to my ears than a 40hz tuning. Quicker and deeper.
I've never heard a 20hz tuning or lower, so I've no idea.
Slam is also integration with the mids (time alignment stuff).
But running 4 x 15's from 500hz to 80hz, then running 4 x 18's from 80hz to 27hz (6th order tuned boosted subsonic at 27hz), that had massive output (along with 110db 1'x2' mid horn and piezo at 5khz). I hadn't realized how much louder speakers will go by removing those really deep stuff. My current 15's start bouncing at a much lower volume than they should (low freq garbage). My kids said "you know when you told up not to blast the stereo, we didn't realize it was for our protection." lol, that system had slam.
The again, the w-bin I had upstairs had slam, but it also lacked the really low stuff (probably rolled from 150hz to -6db near 60hz then gone), but that was the best kick drum. Watching 5th element, the bullets when the car cars were shooting at Bruce Willis' taxi had impact.
Norman
No Norm, what I have now is an extended bass shelf alignment, box is tuned way down low, below 20 hz.
This gives flat bass to 18 hz, but at the sacrifice of midband punch.
I am now going to tune to about 20 - 24 hz instead.
With an EBS alignment, according to Duke, if I understand him correectly, is extended deep bass that works well with corner/wall placememnt.
The corners/walls fill in the bass roll off from the ebs alignment, making the bass of higher quality.
It worked well, and I can always go back, since I will keep the curent ports.
Now, i am looking for max bass impact for dance music, and so I am going to try a higher box tuning, and a theil alignment, as opposed to an ebs.
The thiel/small alignment gives port gain, the EBS does not.
I THINK that is the way Duke explained it ?
He is the expert here, not me.
Changing tuning from 20hz to 24hz, you would not gain any more slam than you have now.
Norman
I am tuned lower now then 20 hz, I will have to ask Duke ?
Go ahead and shorten the ports however much you want.
To give you a few data points to go by, trimming both ports to 9" long would tune to about 20Hz; trimming both ports to 4.5" would tune to about 25 Hz; and trimming to 2" would tune to about 30 Hz.
Party on, my friend!
Me being a dealer makes you leery?? It gets worse... I'm a manufacturer too.
I put the new, shorter ports in there, and bass got boomy and lumpy.
Lost SOME really low bass I had in spades before!
Don't like the conventional tuning, going back to the extended bass shelf tuning you originally designed.
You were right Duke, corner placement of a subwoofer sounds better with the EBS tuning.
Wonder IF I could play with the ports to tune the EBS a little better ?
With the posts you originally designed( the ones about 18 inches long) I get flat bass to 20 hz, and 3 db down at 18 hz
Duke, what parameter are we trying to maximize to get "punchy" dance club and Rap type bass ?
What is the frequency of this chit ?
My subs are both in corners, the room is approx 20 by 24
What about corner gain ?
I only use my subs for watching TV and movies, and now for dancing.
My main speakers do just fine with musical bass.
I really dont want to use a subsonic filter on the woofers, if I can help it ?
I cut the 2 - 3 inch pvc ports to 7 1/2 with a 45 degree angle on ONE end of ports, a "poor mans flare" I learned from YOU!
Honestly, with the longer 18 inch ports in an EBS alignment, low bass was almost scary!
I have over 2000 rms watts to each of the 2 subs, and the low bass is simply staggering, far exceeding 2 SVS Ultra cylinder subs I had previously.
But the upper bass "kick" I am looking for currently is missing, you know, that pounding "club bass" sound ?
Hopefully, by raising the tuning, it will place the bump right where we need it for dance music, and Rap ?
My listening room Duke is an enclosed carport, and has ceramic tile over cement floors, but suspended ceiling tiles.
The bass was so overwhelming, I actually had to "load" the ceiling tiles with thick fiberglass to make them behave!
I know people "poo poo" car stereo drivers Duke, and I am sure there are better drivers then the cadence wild beast 15 inch woofers.
But they work very well, for me.
How are things in beautiful Idaho ?
Oh, I have never been to New Orleans, but I had my first Poor Boy Sandwich and crawfish etoflay recently at the NOLA Cafe, here in Tampa!
The guy from NOLA Cafe is right from new orleans, came to tampa escaping the hurricane!
Man, thats some good food!!
Don't you MISS New Orleans, sometimes ??
The room is a component. So is integrating speakers within a room.
Having read all the above like I shoulda done the first time made me realize my comment is preety dumb. Oh well, I've eaten at NOLA'S and the man's other restaurant in the Warehouse District quite a few times and liked it everytime and didn't know Duke is from there. His last name IS French, tho, I believe. Boy, Idaho is a long way from NO.
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