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15 watts & 94 db eff. speakers: how loud?

With a Trends 15 watt t-amp and small tekton design speakers, with 6 inch fostex 167es, rated @ about 94db, i can get about 93-4 db sustained average (@ 1 meter per speaker) with peaks around 96-7. It sounds perfectly good, nice and clean, no treble break up, nothing different than @lower volumes, only louder.

BUT, at ANY higher volume the amp starts to clip. One hears of many such rigs with even lower wattage 300Bs and such, which is why i wanted the efficiency of the speaker (as well as its single driver design). I've never really used a solid state, much less digital amp before. I'm wondering, is this the nature of hard clipping in digital amps, to begin before there is any real noticeable distortion or is something wrong with the amp? Is this generally how solid state clips? How loud should speakers of this efficiency go with this many t-watts? Finally, how many watts do I need to have some more head room (let's face it, I'm only comfortable with my rig when I know I can accidentally destroy the speakers late one night) : )

Thanks in advance!
thomp9015
thomp9015 OP
79 posts
 
thank you again joelv, i must say that of everything written so far, and most all of it very useful, yours seems like the best answer to my original question, which is essentially: is this clipping to be expected, and you seem to be saying that it does not appear to be. although i'm about the last to know, my impression is that you are probably correct.

i've emailed both the amp distributor and speaker manufacturer...it may take some time but i will at least get some sort of straight forward response from them both and relay them to you. thanks thanks
shadorne's avatar
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shadorne
7,333 posts
 
Most people are blissfully unaware of compression from speakers. It is possible that your amp was actually putting out around 15 watts during transients and therefore clipping - it is simply that these transients did not translate to the peaks you expected to observe but were limited to 96-97 db SPL.

Explanations for this are - limited Xmax or thermal compression from the driver. Generally about 97% of what you throw at a speaker ends up as heat. The Xmax on this driver is a mere 0.6 mm - a tiny 1 inch voice coil ( no bigger than a tweeter voice coil) I mean $%#^& - what can you possibly expect out of a driver like this????

I have written several times in A'gon forums about the issue of prevalent use of cheap drivers (often used in expensive speakers). They work great at lower volumes but you cannot expect miracles. Soundstage (who do lab tests ast Canada's National Research Council facilities) state that the do not even test speakers with signals above 100 db SPL as this would DAMAGE MOST OF THEM!!!
thomp9015 OP
79 posts
 
shadorne, i see what you are saying, i've read a lot of your posts on this topic, just two unversed to put 2 and 2 together. it just seemed like the speaker was able to do more spls when it was clipping (no noticeable harshness or distortion). it does seem like a delicate little driver but compared to some others, it doesn't seem all that cheap. but within its limits it still sounds very nice for what it is. thanks, this has all helped me feel less in the dark.
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shadorne
7,333 posts
 
Thomp9015,

I am not saying it is a bad driver. At $65 retail (probably less wholesale or in bulk) this is a great and well respected driver and will sound awesome at lower volumes than 97 DB SPL.

All I am really saying is not to expect too much - after all to get good clean loud sound above 100 db SPL you are probably looking at something much bigger - a three way or something with perhaps $600 or more worth of drivers. You know - don't expect miracles - or don't believe the math that suggests that a small 94 db SPL full range driver should be able to easily play 110 db spl comfortably (with pure theory suggesting that all you need is a big power amp).

Of course amplifier manufacturers often neglect to mention this as they are often trying to sell you higher end amps with more watts...in a sense they are competing with speaker manufacturers for a piece of your overall "system budget."
thomp9015 OP
79 posts
 
shadorne, you're absolutely right, don/t worry, i really love the speaker for what it is, i guess i'm really just trying to find that final volume margin of good sound from them, i know i'm very close, maybe already there, always looking past the horizon perhaps.

still, i would like to have enough headroom with an amp to hear some distortion from the speaker before the amp clips, i can't say why though, since i wouldn't listen to it distorting, i just want to make sure the amp is not the limiting factor in quality output (and also simply trying to understand the system's interrelationships), maybe i just have too much time on my hands : )
thanks
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