List of Reference Level, High Sensitivity & SPL Speakers - Page 16

Glad to see that I'm not the only one who's noticed this.

Not that sentence... I'm generally non-responsive to personal commentary as it distracts from the topic in a useless manner. I'm sure you meant your comment as constructive criticism; but it's simply not a productive topic.

I was confused where you were going with the rest of your post.

The rest of my post was addressing what you said a few times: that you have non-HS speakers that compensate (somewhat) with high power, that you are happy with that and seem to want this thread to acknowledge as a means of achieving reference level. That was perfectly obvious, but you are looking for arguments everywhere...

If that's what you've taken from my posts you have an incomplete understanding of what I've said (one which lies at odds with things I've said).

I don't think I've seen a definition of "high sensitivity" . I stated in a post that I can only assume that not of my speakers qualify.
I have not discussed compensating for anything. Go back to my first post on the thread and the question I was answering to understand how the power/sensitivity conversation came up.

I'm not looking for anything. I think people imagine tone and motivation through the lens of their own preconceived notions. As I rarely fall into well defined categories, it often frustrates people who launch off from one position of mine and assume I do. Then when I don't match the pigeon-hole they've imagined: the name calling and accusations begin.

For fun: go back to post 444 and try reading all the posts that are not mine. Imagine it's you that's being discussed in all those posts. Now tell me what seems adversarial and confrontational (or passive aggressive).

I do sometimes feel like an agnostic trying to have a conversation with religious zelots. I know I've seen more than one builder unwilling to discuss HS much specifically because of the zelotry and mud slung by a few.

Here's a question for you: Have I recommended to posters that they should peruse high-sensitivity speaker here on AVS in the last month? Have you been assuming I'm opposed to them in some way? Where did that assumption come from and how to you reconcile it with the three times this month I've specifically recommended that someone might be best served with high-sensitivity speakers?

I suspect this is my one and only post on my posts. I could be wrong, but I don't see the point of a meta-conversation about posts rather than their content.

Eyleron,

Just wanted to that you again for starting this thread man. Learning a ton!

HolmImpulse does distortion as one of the options in a frequency response sweep. You can even separately chart each THD component, 2nd through 10th harmonic.

Ok, so I went back...
I am not sure where this claim came from, and how it is relevant. Let's try this:

To reach the same (reference level, so high) SPL, a higher sensitivity speakers will have less distortion (compression and otherwise) than a low sensitivity speaker.
You pointed out that this isn't necessarily true because a crossover can affect sensitivity. That's true enough.

I pointed out horn-loading, and Bill said that less excursion was used to achieve the same SPL in HE speakers (which is only true with horn-loading and the like; Chu pointed out that in fact more power was used to reach the same excursion and SPL in a low-sensitivity speakers relative to HE, thus implying changes in sensitivity in the crossover and the like and not horn-loading).

Many HE speakers use horn-loading and wave guides as a means to get there. In these cases, the cone displacement is less and along with that, distortion. If sensitivity is changed in the crossover (sucking up power at certain frequencies) then it's another ball game. Typically (a word you won't like), a 105 dB sensitivity 100W speaker playing at 10W peak will sound less compressed than a 88 dB sensitive speaker playing at 500W peaks. Low sensitivity doesn't scale well to vey high SPL; at some point the heat has to go somewhere.

All of this suggests that a useful metric for speakers would be compression charts of some sort. This might suggest more optimum crossover points.

Peter, did you read the comment I made where studies subsequent to Klipsh's work called into question aspects of his paper and further comments that suggested horn speakers tend to audibly mask distortion components that pistonic speakers tend to reveal?

Horn loading or using multiple drivers. With multiple drivers you get 6dB higher voltage sensitivity per doubling of driver count, which also translates to half the excursion per doubling of driver count for equal output. The advantage to multiple direct radiating drivers is ease of construction, the disadvantage is the cost of the drivers. Manufacturers long ago went to the multiple driver option, as for them using more drivers is less expensive than the labor costs of building horns. For the DIYer capable of building horns they're the less expensive route.

True enough Bill, thanks.

Chu, I saw your post but did not investigate. Sure goes against my own personal observations whereby my horn speakers always reveal detail I had never noticed on other system , and Bill's horn-loaded design of the Tuba HT has the cleanest least boomy LFE I have experienced.

Reference level means that the low sensitivity speaker won't be well beneath it operating limits. You'd need 670Watts to get 105 dB from a 88 sensitivity speaker 12 feet away. A 105 dB sensitivity speaker will require 13 watts to get 105 dB 12 feet away, 50 times less. It will be well beneath it operating limits. Unless you can give me an example of a HE 20Watt speaker from the list?

Fostex, though I don't see any on the list. Highly valued by those using 10 watt and lower SET amps.

I don't consider either a high sensitivity speaker.

+1. There's no set definition but most agree that 95dB the lowest that should be considered high sensitivity. Still, many horn purists call that medium sensitivity, with 100dB or more being high sensitivity.

You can't tell just based on sensitivity and power. You need to know what type of drivers and how linear they maintain while putting more power to them. I mean just because a speaker is 90 dBs sensitive with a max power of 400 watts does not mean it will take all that power cleanly, nevermind holding its natural response. Maybe it hit 400 watts and max spl at 500 hz only and the rest were compressed. The only way to know for sure is to measure THD and do sweeps for when your speakers or subs will compress. How many times do you see people posting a graph at 80 dBs being flat to 10hz to 100hz. Nice but will it Maintain that response when running at spirited levels? All speakers and subs will fall apart at some point. I think Tom Danley mentioned something like 1/8 or 1/10 of the power will start to show effects of compression. Well there is a reason these high powered and high sensitivity speakers exist. I just added T-39's to my surrounds(W8's) and the sound from them now have awesome full powerful sound with slamming Midbass, why does it matter, because I had enough spl for reference already but now I raised the bottom to match the top and wow!

Again, when speakers are close in max spl then it matters what Drivers, crossovers, etc.. Are used.

That begs the question: What are their limits? You can't tell that from the thermal power ratings. You can easily find 500w rated woofers that will reach 10% THD with only 50w input, and 250w rated woofers that will take 250w without reaching 10% THD. So just as manufacturer sensitivity ratings without SPL charts to back them up are worthless, so are manufacturer thermal power ratings when actual measured power at 10% THD is what matters.

+1

Thus my example of 105 dB.

Not bad, but MKs stacked DR250s gets him to over 109dB/w, per stack. He can get reference from a 15w Lepai running off a battery.

Active I suppose. Doesn't the required EQ eat up a lot of that headroom? (I recall MK mentioning EQ) For example I could drive the Tuba HT to reference with 10W, but my room response is pretty bad (and placement options limited by the sheer size of the THT) and so I aggressively EQ to get the best response and have up to 13 dB of gain at a certain frequency (!!). I have to admit the EQ was done uisng a Radio Shack SPL meter as the microphone, with dubious corrections (still a fairly linear gradation) so it needs to be redone with a proper mic, and then the room addressed with bass traps until I can cut some of that EQ. Still, the headroom was there to play it and I used it to get the best sound. And it sounds great!

What's being talked circles around is this:

Different speakers distort in different ways, and at different points relative to their max power handling, and there is nothing in sensitivity or max power handling or the like that will tell you how or how fast that distortion will kick in.

A 94db sensitive speaker may or may not get louder with lower distortion than the 96db sensitive speaker next to it. There is no way to tell from the information given. In some general sense, there likely is a trend favoring high sensitivity (certainly extreme differences in sensitivity would be difficult to overcome other ways), but that generalization cannot be assumed true for a specific pair of speakers.

Also: it's not always clear what percentage of power handling a driver is actually at.
Not all drivers in a cabinet are equally sensitive, and it's possible that some drivers are actually being run at a smaller fraction of overall power than the speaker is.
Even within the driver that is the limiting factor, it's not uncommon to deliberately reduce sensitivity via crossover to extend the -3db point.

Thke a 96db driver that is -3 at 60 hz and is -9db at 50Hz. Run the whole thing -6db in the crossover with a rising slope from 50Hz to 65Hz, and you get what appears to be a 90db sensitive driver that's -3db @50hz.

Do you really think distortion at SPL above 60Hz is at all changed by this? Of course it isn't, yet sensitivity is actually lower.

Exactly. 105 dB vs 88 dB sensitivity makes a pretty generalized comparison; there's no point in comparing 94 dB vs 96 dB.

I will assume that we are not comparing a 20,000 speaker that is rated at 88 dBs at 1 watt and can take say 2000 watts compared to a $200 speaker with 95 dBs. Why? Because I would hope that the expensive speaker does not use a driver that would fall apart before any signifcant power being used and that $200 speaker might be using crappy drivers that are rated for 400 watts but could only take 40 watts in reality(As Bill mentioned). It always depends on the drivers used but we are saying there are many excellent drivers for cheap that will not only take good amounts of power but don't need to because they will play loud with 10 watts. When this happens the drivers don't move much which keeps their THD down and much cleaner.

BTW,
Bill is close to my sensitivity in my room, I am at 112 dBs from 100 dBs and up. I use about 4 watts for reference and just in case I am using my 500 watt per channel amp on them. It delivers pure class A the whole time because it uses so little power. It switches at 50 watts to AB. I will tell you something, I just added my T-39's to my W8's for surrounds and the surrounds sound amazing now with that kick from 80-200hz! Best surrounds ever!

EQ will lower sensitivity but the headroom will always be there but I never use the headroom needed. I can tell you guys that I got a full 6 dbs increase adding the second DR-250. The clarity and dynamics are off the charts. I have owned other high sensitivity speakers and these are much more sensitive and dynamic. These are almost 10 dBs more sensitive than my JBL's and 13 dBs more than my eD's. Those were the most sensitive prior to the BFM stuff. Oh, and these sound better to boot.

One more thing, I just had my friend over who has hearing good up to 24khz(I call him dog ears) and he has been with me since I first built my theater and we A/B systems or speakers and subs every step of the way noticing the pros and cons of each system or whether I downgraded rather than upgraded(I have done that a couple times as well). I threw in some demos yesterday and he was puzzled, he looked at me and said what did you do and I said I added the T-39's to the surrounds and I tweaked my EQ for the center and subs. He then said this is the best it has ever sound and don't you change a thing! He said I am not kidding, it is not even close, the energy, clarity, dynamics, are all much better than ever. The detail is much better as well. This happens to be the most sensitive system I have put together as well.
Edited by MKtheater - 12/9/12 at 9:53am

MK

W8 and T-39, I am guessing they are Bill's wedge 8 and Titan-39 horn sub. If this is correct, how much room a single combo takes? I vaguely recall you did not have much space for the surrounds. have you thought of dropping the eD subs and going BFM all the way?
Edited by zheka - 12/9/12 at 11:17am

I have the 22 inch wide T-39's. they stand in the back corners toed in. My subs go to 5hz so I won't be changing.