Its still my fault for not being specific....I was just comparing the sub bass capabilities.
So how do you guys look at xmech and its usability?
So how do you guys look at xmech and its usability?
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In general, xmech is considered to be more of a safety/failure limit (i.e. the voice coil approaching the back plate), but this depends on the manufacturer.
For this reason it's also reffered to as 'xdamage' and as such not exactly usable 😉
For this reason it's also reffered to as 'xdamage' and as such not exactly usable 😉
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No, ultimately one chooses the driver best suited for the needs of the intended app, but in general one designs an alignment based on a specific set of driver specs ['horses for courses'], so the H being optimized for a low bass tuning would normally only be used higher up if a primary performance goal is max SPL down to tuning.
GM
Marcel, I am well aware of Dr. Geddes' and your opinion in this respect. I've read the discussions about this topic on hifi.slovanet as well.
There's much more to this than just 'damping a cone'.
It's about every part of the driver, the composition, coating, thickness and shape of the cone (ribs or not), the (material) properties of the spider, surround, the motor structure etc. etc.
A heavy cone pushed towards its breakup doesn't sound particularly good, I've heard it several times. Nobody I know, prefers the muffled sound these heavy diaphragms produce in the midrange to a well designed (light) midrange cone driver with extended usable response.
With some music (electronic for example) the difference may be less obvious, but once you listen to acoustic instruments and voices there's no denial.
Why would B&C or any other manufacturer even sell midrange drivers if a subwoofer driver would suffice?
After all the TBX100 is only slightly more expensive than the PLB76, yet it's obviously more expensive to manufacture (bigger magnet, demodulating ring, double spider etc.).
Let's just put our conceptions to a virtual test.
We both like Celestion drivers.
So let's build 2 virtual all-Celestion 2-way cabinets.
Horn: H1-9040P
Comp. driver: CDX1-1747
We'll pick 2 different 15" drivers:
- TF1525, a basic and cheap midwoofer with a stamped steel chassis.
- FTR15-4080HDX, the top of the line 15" woofer.
We use both drivers in 2 separate, optimized 2-way cabs with the horn integrated in the baffle. The XO is 1200Hz, the lower usable limit for the CDX1-1747 at which distortion figures will remain within the 'comfort zone'.
After finishing the cabs we'll have a panel evaluate both. I bet very few, if any, members would prefer the midrange of the FTR15-4080HDX loaded cab.
A glance at the specsheets shows why.
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Technically, both are wide band bass drivers; sub [infra] bass is <20 Hz, but we have DD & THX to thank for <120 Hz being a 'sub' woofer.
Originally it meant when the spider had 'wrapped' up, stopping cone travel and if power was still being applied it could melt the VC and/or tear the coil/cone apart.
As motor design advanced, the spiders could allow the VC to bounce off the back plate or drive the VC completely out of the gap [my Altecs, etc., through the '70s], sometimes slamming back in at a slight angle to make them drag or get wedged in with of course $ catastrophic results $.
Haven't paid any attention to modern driver drawings/cutaways, so not sure how they deal with these huge Xmax drivers.
GM
Well thats that I guess....I emailed Acoustic elegance about changing the order of 1 pair of the TD15m's to a pair of 18+ with pricing before change. He might do it. Haven't heard back yet, after about 4 days or so......I bet hes got so many emails of people asking about their orders....no new updates on the facebook page either.....
I know there were other references to alternative woofers....I think when trying to cover as wide of a spectrum, the TD15m is top 5 easily. Now that I am speculating a sub as a part of the program....what super light coned woofer do you guys think would be your choice for a 15" mid/midbass to be crossed to -> what would your choice be for a 18" sub?
I figure since I am shortening the band that there might be a woofer I passed on before due to lack of bass extension...and we never really focused on selecting a 18" sub until now.
What say though, well of opinion and wisdom.
I know there were other references to alternative woofers....I think when trying to cover as wide of a spectrum, the TD15m is top 5 easily. Now that I am speculating a sub as a part of the program....what super light coned woofer do you guys think would be your choice for a 15" mid/midbass to be crossed to -> what would your choice be for a 18" sub?
I figure since I am shortening the band that there might be a woofer I passed on before due to lack of bass extension...and we never really focused on selecting a 18" sub until now.
What say though, well of opinion and wisdom.
Follow-up:
I've simulated some B&C subwoofer drivers, including the TBX100. For a high SPL - and power hungry - 2-way (or 3-way with the DCX1464) crossed at max. 600Hz, the TBX would be an excellent driver.
I've simulated some B&C subwoofer drivers, including the TBX100. For a high SPL - and power hungry - 2-way (or 3-way with the DCX1464) crossed at max. 600Hz, the TBX would be an excellent driver.
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The TD15M is (still) a top-class midwoofer.
The TD18+ is probably one of the most efficient 18s on the market.
However, the TD15H beats it wrt low freq. extension.
The TD18+ is probably one of the most efficient 18s on the market.
However, the TD15H beats it wrt low freq. extension.
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MTM with a ported Td15m is desirable but spacing all that volume out above and below a 23" horn aaaannndd making it so that I can adjust the pitch of each woofer to focus on the sweet spot....thats a serious diy project right there. I am a fan of KISS.....
So if I just ran a 2 way with a sub....that takes care of the lobing problem for the near field
It also keeps my mid woofer from excurting past this magical 3mm.
So if I just ran a 2 way with a sub....that takes care of the lobing problem for the near field
It also keeps my mid woofer from excurting past this magical 3mm.
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I don’t get how a heavier cone could be ‘better’ choice for playing 1khz compared to a substantially lighter cone 15” woofer??
My personal (albeit subjective) experience is units like Altec 416, ae td15m, tannoy hpd, faital 15pr400 can play mid lows with more speed/clarity compared to heavier/less sensitive coned woofers (jbl 2235h, beyma 15g40)
What amount constitutes ‘high-spl’?
My personal (albeit subjective) experience is units like Altec 416, ae td15m, tannoy hpd, faital 15pr400 can play mid lows with more speed/clarity compared to heavier/less sensitive coned woofers (jbl 2235h, beyma 15g40)
What amount constitutes ‘high-spl’?
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LMAO !!! I'm glad someone else caught that...I didn't have the balls to stick my neck out there to get it chopped of rofl!
Of course there is more to this, and drivers like the TBX series have all of it. The only thing that TBX100 doesn't have compared to PLB76 is the sensitivity (that is the reason special midrange drivers exist) but you don't need that sensitivity for a home use. On the contrary, I would say too high sensitivity is not a good thing because of the noise - much more demanding for the electronics.
In fact I wouldn't use any of those because I consider them not well damped. And "if the frequency response is not good, nothing else matters".
I used, measured and made crossovers for all those drivers in the recent years so I'm also telling you my experience. Of course yours may be different. Oh, and please don't take me wrong - I've also listened 🙂
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In the end it's primarily a question of approach/philosophy.
It's exactly the sensitivity that matters to many people.
I've heard SET and low power solid state Class A amplifiers that didn't have any noise issues at all, even with 100dB loudspeakers.
It's exactly the sensitivity that matters to many people.
I've heard SET and low power solid state Class A amplifiers that didn't have any noise issues at all, even with 100dB loudspeakers.
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umm.. but we are usually pairing these woofers with compression drivers mounted to horns with sensitivity even higher than the woofers. Is it not ideal to get the woofers as close to sensitivity of the mid:high channels so less attenuation needs to occur (ie less overall signal quality loss)?
High frequency capability has nothing to do with cone mass. This is a common misconception. Sure it seems logical that a heavier cone would be harder to move at HFs, and that is certainly true, but the radiation efficiency rises with frequency making the net result independent of mass.
Ahhh, listening! The quickest way to convince yourself of what you want to believe. It's what we all do in the end, but it is a very poor way to get to the best result.
Reductive eq shouldn’t necessarily result in loss of signal quality. Additive eq is the one to worry about. Either way the less eq needed, the better, which is why I chose a traditional round horn btw.
Nope. Sensitivity differences don't matter.
If gain staging is done correctly pre-attenuation, there shouldn't be any degradation of signal quality.