A question of Great BASS response

[ClaudeJ1]

If you look at the ISO "equal loudness curve" you will see that bass rolloff of ALL SPEAKERS (yes, even the venerable K-horn) needs lots of boost if one is to have truly realistic bass response.

Having gone to the Jazz Kitchen in Indy last Friday, I was treated to live music. The 5-string bass was in the corner, then guitar, then horns, with all of the percussive instruments up front and piano to the left. I was sitting in the "sweet spot table" and noted the absolute quality of the sound. Every note from every instrument could be heard, expecially the bass.

Very few speakers are truly flat to 30-40 Hz. which is the range on a low string of a modern 5-string electric bass B-string, or a loosened E-string on traditional 4-string bass. On a Return To Forever Blue Ray, it's obvious that Stanley Clark uses some kind of sub-bass synth to create a FEEL for the low notes while maintaining the detail of the fundamental notes and their high order harmonics.

Great bass is the most expensive thing to get a hold of in a sound system and can only be had with multiple SUBWOOFERS to smooth out the peaks and dips in the room. According to the experts at JBL, as shown in Dr. Floyd Toole's chapter on this subject, 4 subs in the CENTER or each of 4 walls is best. This conclusion came after studying over 50 subwoofer positions in different combinations. Putting 4 in corners give you the lowest extension, but at the cost of smoothness in different seats. Putting 4 in the middle of walls give the smoothest in different seats at the cost of weaker super-low notes. The best overall compromise, economically AND aesthetically, was shown to be with only TWO identical subs in center front and center rear walls.

Like Roy Delgado says, in keeping with PWK's laws about reducing cone motion to reduce AM/FM/IM distortions: "The high frequencies is where the least amount of driver motion occurs and the BASS is where the most cone motion occurs (hence the greatest distortion of all types). Therefore, the bass is the first place we should be horn loading, yet, commercially, it's the last place where it is typically done."

So I am now is BASS HEAVEN with my front and rear Danley DTS-10 "Super Spud" Subwoofers. These super subs produce 100 db for a 1 watt input, so with 500 watts of peak power per cabinet, I can reach 130 db peaks in my room, which can handle the reproduction of Danley's fireworks recording with ease. They are designe to operate from 10-60 Hz. They take full advantage of cabin gain of 12 db per octave below 30 hz. With a little EQ help from Audyssey, It is BY FAR, the best "bottomless" super-detailed bass I have ever heard of felt on music and movies. The LFE special effects typically vibrate "stuff" 2 to 3 rooms away from the living room, which is the far corner of the house I"m in. The 24 cubic foot box containing a 24-foot long tapped folded horn filters out the acceptance of all but very few wives and/or girlfriends, LOL.

As another FYI, the president of Danley Sound Labs has 4 of the Spuds in his living room (the ones with the twin 8" Tang Band drivers in each cabinet). So for those of you with only $1200 to spend on sub woofage, you would only sacrifice only a small amount of output from 10-15 hz. if you were to build your own 4 spuds rather than buy only two super spuds like I have.

Go forth and conquer some extreme bass, wouldja!!

Edited November 19, 2013 by ClaudeJ1

[derrickdj1]

I enjoyed reading your impressions because you hit several reat and key points. All speakers roll off and even large speakers can benefit from a subwoofer. Two or four subwoofers work best. Also, PWK law on keeping cone motion down and that the bass frequencies lead to more cone breakup than the HF. Glad to hear you are enjoying the music!!!

[NBPK402]

Theoretically.... You could use a 15 DBW amp for each sub and reach reference levels, correct? THX specs are 115db on peaks I believe. I know you are referring to 2 channel but I would think the levels would be similar. I know I will not be listening above 115db.

Edited November 19, 2013 by ellisr63

[oscarsear]

I have an RSW-15 centered between my Khorns - does this count? Question - do you find that the bass volume needs to be tailored per recording?

[ClaudeJ1]

Theoretically.... You could use a 15 DBW amp for each sub and reach reference levels, correct? THX specs are 115db on peaks I believe. I know you are referring to 2 channel but I would think the levels would be similar. I know I will not be listening above 115db.

I could have posted this in the Home Theater section, since I switch between 2.1 and 5.1 on my Onkyo. As far as power, Each driver can handle 500 Watts peak x 2 x 2 cabinets, so I could use a 1 KW amp per cabinet, but I'm happy with a 300 wpc Bryston 4B and an Adcom 555. Since the amps see about a 2 ohm impedance they draw more current at lower voltages, but these amps have no problems. One of the DTS-10's came with a 3/4 inch Plexiglas window so I can observe cone motion. Only during the sub-20 Hz. LFE stuff do I detect any cone motion. On 2.1 music, I don't see any at all even during heavy bass passages. I like gobs of headroom and I don't listent that loud, although I just watched "Man of Steel" and "Tron" and my Radio Shack meter registers above 105 db near the mouth of the rear horn, which has 3 db less drive than the front. They will be equal once I use the R and L channel of one amp, instead of the R and R channels of 2 amps, now that I have determined I am not taxing them at all. I was just trying to play it safe with separate power amps.

[ClaudeJ1]

I have an RSW-15 centered between my Khorns - does this count? Question - do you find that the bass volume needs to be tailored per recording?

Not for me, no. On my test/reference CD's, everything sound great as is. It's just that some producers give you too thin or too thick bass, but I just leave the controls alone.

[NOSValves]

Come to my shop and you will hear realistic bass without subwoofers.... from modified Lascalas with some placement tweaks. I've been tweaking at it for no less then ten years. I still have a few tricks up my sleeve but I'm about 95% done.

[CECAA850]

Come to my shop and you will hear realistic bass without subwoofers.... from modified Lascalas with some placement tweaks. I've been tweaking at it for no less then ten years. I still have a few tricks up my sleeve but I'm about 95% done.

You couldn't make that statement if you used them for HT. I'll bet they sound awesome for 2 ch though.

[CECAA850]

I could have posted this in the Home Theater section, since I switch between 2.1 and 5.1 on my Onkyo.

We now have the subwoofer section back also.

[mark1101]

A pair of DTS-10s in a room definitely makes a lot of bass.

[ClaudeJ1]

Come to my shop and you will hear realistic bass without subwoofers.... from modified Lascalas with some placement tweaks. I've been tweaking at it for no less then ten years. I still have a few tricks up my sleeve but I'm about 95% done.

You couldn't make that statement if you used them for HT. I'll bet they sound awesome for 2 ch though.

Well you are talking to a guy that had 4 MWMs with twin VMPS subs. I have also owned 1/2 dozen LaScalas for home and DJ work, so I'm no stranger to bass of all types. Un-EQ's LS bins have a high peak in the 125-150 hz. range, just like my FH-1's, which are the closest thing to a K-LS bin, except braced better. MWMs have a 55 Hz. peak, which give them the built-in disco thump.

I still think the best driver for a LaScala is the K-43, since it's high BL product gives it much better performance in the 200-400 Hz. range, mating up to the K-400 much better. Yes it sacrifices the low end, but that is what subs are for.

Mine are used for music AND for the LFE channel both. There is GROSS distortion while one attempts to EQ anywhere near the ISO curve shown here.

[ClaudeJ1]

Now I believe these curves were done for headphone listeners, which make the whole thing skewed, if that's the case. However, I listen between 80 and 85 db at my sweet spot, which means, according to the old and new curvers we need a 30-40 db boost at 20 Hz.

Even if it's only a 20 db boost for speakers in a real room, you will never get that without a sub. Horn sub preferred for reasons stated at the beginning of my post.

[Quiet_Hollow]

ISO equal loudness curves are phons vs. freq not SPL.

Their is no direct correlation between the chart and what is required from an actual sound system.

[dtel]

I love the way the sound of the "regular" size spud blends with the MWM's, the two horns seem to work well together.

The room has never been tested, or checked in any kind of way so I have NO idea what's going on, but I like it, if I were to change anything it would be another spud in the other corner. The crossover is at 40 and only fills in where the MWM leaves off, I tend to keep it simple..

OK I'm easy to please just keep the music playing.

[mark1101]

I never had any Danley's but have heard several. I was very happy with the horn sub sound of my Bill Fitzmaurice Titan 48s, and how they mated with the MWMs. In fact I kept them because I liked them so much.

I have since moved to KPT-684 subs which of course are not horns, but brought me to an "all Klipsch" fully THX approved MCM system. I have to say they produce way more thump than the horn subs. But........they each have dual 18" drivers vs. single 15" drivers in the Titans. So not unexpected.

Claude I agree with your very first post. Danley got way ahead of everyone with his tapped horn engineering. If you study it, it is pretty darn smart what he has been doing. But you do you need a very sturdy and powerful driver in those tapped horns and a powerful amp for it all to work as designed. So running Danley's does not come cheap.

[NOSValves]

Come to my shop and you will hear realistic bass without subwoofers.... from modified Lascalas with some placement tweaks. I've been tweaking at it for no less then ten years. I still have a few tricks up my sleeve but I'm about 95% done.

You couldn't make that statement if you used them for HT. I'll bet they sound awesome for 2 ch though.

I'm pretty sure this is the 2 channel forum so HT has zero to do with it. I gave that mess up years ago. All it took was one get together with a bunch of grown men obsessing over an animated fish on the TV screen to make me realize it was just plain silly

[wuzzzer]

My subs are rated at 100dB/1 watt for each cabinet. I have them stacked so I believe that should technically give a 106dB/1 watt output? In any event they're the best subs I've ever experienced for 2 channel use.

[CECAA850]

Come to my shop and you will hear realistic bass without subwoofers.... from modified Lascalas with some placement tweaks. I've been tweaking at it for no less then ten years. I still have a few tricks up my sleeve but I'm about 95% done.

You couldn't make that statement if you used them for HT. I'll bet they sound awesome for 2 ch though.

I'm pretty sure this is the 2 channel forum so HT has zero to do with it. I gave that mess up years ago. All it took was one get together with a bunch of grown men obsessing over an animated fish on the TV screen to make me realize it was just plain silly

The OP stated he was switching between 2.1 and 5.1 (LFE channel in movies) and could have posted this in the HT section as well.

[ClaudeJ1]

.

Claude I agree with your very first post. Danley got way ahead of everyone with his tapped horn engineering. If you study it, it is pretty darn smart what he has been doing. But you do you need a very sturdy and powerful driver in those tapped horns and a powerful amp for it all to work as designed. So running Danley's does not come cheap.

No kidding. I have spent as much money on just subwoofage and amps as the rest of my system, including a 55" HDTV. But it's the best yet, so I will just enjoy for while, eh?

[ClaudeJ1]

ISO equal loudness curves are phons vs. freq not SPL.

Their is no direct correlation between the chart and what is required from an actual sound system.

I agree with you, but the left hand column clearly says "DB"

By definition, the number of phon of a sound is the the dBSPL of a sound at a frequency of 1 kHz that sounds just as loud.^[3] This implies that 0 phon is the limit of perception, and inaudible sounds have negative phon levels.

The equal-loudness contours are a way of mapping the dBSPL of a pure tone to the perceived loudness level (L_N) in phons. These are now defined in the international standard ISO 226:2003, and the research on which this document is based concluded that earlierFletcher–Munson curves and Robinson-Dadson curves were in error.^{[citation needed]}

The phon unit is not an SI unit in metrology. It has not been accepted as a standard unit by the United States National Institute of Standards and Technology.^{[citation needed]}

The phon model can be extended with a time-varying transient model which accounts for "turn-on" (initial transient) and long-term, listener fatigue effects. This time-varying behavior is the result of psychological and physiological audio processing. The equal-loudness contours on which the phon is based apply only to the perception of pure steady tones: tests using octave or third-octave bands of noise reveal a different set of curves, owing to the way in which the critical bands of our hearing integrate power over varying bandwidths and our brain sums the various critical bands.^{[clarification needed][citation needed]}