New Sub's?

[sunburnwilly]

but why in the world doesn't Klipsch provide an overkill flagship subwoofer?

Better yet an overkill horn loaded sub to match it's higher tier Heritage speakers ? Why do we have to go to outside sources ?

[psg]

There are two kinds of DIY'ers, those that are cost conscious, and then those that are chasing performance that's not offered commercially.

Ain't that the truth...

A combination, for me. An option would have been the DTS-10... a C$4000 option now that it is only sold assembled. I don't think I could spend under C$1000 and get the performance of the Tuba HT with amplification and EQ. So I am chasing performance that's not offered commercially at a price point. If it doesn't best my Hsu STF-3, I promise I won't keep it!

[CECAA850]

Here's a quote from Mr. Hurds (whom I respect) referenced thread.

The distortion measurements?

If so, Pretty much what we where doing is driving the sub with a sine wave at that frequency and then turning up the voltage until the distortion hit 10% (Which is 20dB below the fundamental)

If you look at say one that says "60hz" you will see that it has distortion at 120hz, 180hz, 240hz, etc... So we wanted to get it so the highest non fundamental frequency was at 20dB below the fundamental.

We then took down the SPL 10M, which you would add 20dB for 1M SPL.

What this pretty much does is gives a good real world indication of the real world performance you can expect, because 10% distortion is reaching the limits of the driver.


So if we look at the T30 at 80hz we drove it to 50v since that was the highest voltage that Bill recommended, and it only hit 2% distortion and hit 126dB at 1M.

Then if you look at 40hz, when it hit 10% distortion with 43v and hit 111dB at 1M.

So those are kind of SPL that you could expect in the real world.

To me, it seems that if the subs are driven to their correct voltage, there's very little distortion. Am I reading this incorrectly? Is 10% unacceptable? How would it's distortion compare to a JLAudio sub?

[psg]

So maximum usage output of a Tuba HT at 40 Hz is 96 dB at 10, or 116 dB with no room gain, or possibly up to 128 dB with 12 dB corner gain. That sounds loud to me, which is all they are measuring here (i.e. how loud it can get). What you might want to know is distorsion at 115 dB reference level, so possibly 13 dB below maximum (let's say 10 dB, which is 3.2 Volts or a couple of Watts into 5 ohms).

[michael hurd]

I would count on no more than 6 db in a corner gain, and that's referenced to 1m. SPL falls off as you get to the listening position.

40hz took 32 V to get to 96 db outdoors, but at 50 hz it required 65 V to hit 104 @ 10% distortion.

You would need an amplifier capable of over 1KW into 4R to hit 65 V, a far cry from a 50 watt amp. By the time you apply corrective eq, and add a big enough amp to swing those kinds of voltages, you are talking quite a few bucks. Cheapest option IMO would be a Behringer EP2500 / 4000 and a Behringer Feedback Destroyer Pro. That's still between $420-500 depending on shipping in Canuckistan.

You don't need 130 db capability from your sub? Ok, well lets say you want to get to 115 db @ the listening position which is 4M away from the sub. Spl falls off at a rate of 12.08 db / 4M outside, so we will say you have some room modes and you loose about 8db. you now need in excess of 123 db @ 1M, and that's with zero headroom.

Even though the voltages are high, with the high impedance spikes, power dissipated across the device will be rather low. 32V into 4 ohms is 256 watts. 32V into 30ohms is around 34 watts. In order to not get close to the rail voltage in the amp, you need an amp that can swing higher than that.

The higher the impedances, the higher the voltages that are required in the amplifier. Like the earlier example with 65V, that's over a KW into 4R.... you need an amplifier with capabilities higher than that.

[psg]

I would count on no more than 6 db in a corner gain, and that's referenced to 1m. SPL falls off as you get to the listening position.

I thought 6 dB was just a wall.

40hz took 32 V to get to 96 db outdoors, but at 50 hz it required 65 V to hit 104 @ 10% distortion.

I would have expected around 80V given the 8 dB increase in SPL...

You would need an amplifier capable of over 1KW into 4R to hit 65 V, a far cry from a 50 watt amp.

Obviously a 50W won't reach the limits of the sub. I was implying that i didn't need to reach them either. A 50W amp gets me to 16V into 5 ohms, which is what I thought the impedence was, after horn-loading.

By the time you apply corrective eq, and add a big enough amp to swing those kinds of voltages, you are talking quite a few bucks. Cheapest option IMO would be a Behringer EP2500 / 4000 and a Behringer Feedback Destroyer Pro. That's still between $420-500 depending on shipping in Canuckistan.

You don't need 130 db capability from your sub? Ok, well lets say you want to get to 115 db @ the listening position which is 4M away from the sub. Spl falls off at a rate of 12.08 db / 4M outside, so we will say you have some room modes and you loose about 8db. you now need in excess of 123 db @ 1M, and that's with zero headroom.

4 m from my sub gets me almost in another room! 1 to 2 m is much more likely in my case, unless you count the reflected path to the corner and back.

I don't see why you are being so argumentative here. First you say it's high in distorsion but is loud. Now you are saying it needs one 1KW to get loud. If a horn-loaded 15-inch driver doesn't outperform my 12-inch 300W Hsu STF-3 in my room, I'll let you all know! If it needs more than 50W, I have a 650W bridgedinto 8 ohms amp that I can try, and I can buy pro amp on the used market as well. I am putting a 300W driver in there, so there is little point in going to kilowatt power. My 50W amp is actually more like 65W stereo into 8 ohms and 130 into 4 ohms, so that's only 4 dB below maximum excursion anyway.

I get it. Klipsch forum so not the best place to discuss alternative subs. At least not this thread anyway. I'll keep my comments to my build thread, and off this forum completely if I get an official notice.

[CECAA850]

I'll keep my comments to my build thread, and off this forum completely if I get an official notice.

Keep posting. This is a subwoofer section, not a Klipsch exclusive subwoofer section. I'll bet if you took a poll, you'd be amazed at the number of members that own Klipsch speakers and NOT their subs. I doubt AMY will drop the hammer on this thread unless you start discussing subwoofers and how they effect politics[].

[DrWho]

First you say it's high in distorsion but is loud. Now you are saying it needs one 1KW to get loud.

It's loud at high frequencies. As you go lower, it's efficiency is dropping like a rock. Just work back the sensitivity from the measurements...

I get it. Klipsch forum so not the best place to discuss alternative subs. At least not this thread anyway. I'll keep my comments to my build thread, and off this forum completely if I get an official notice.

I think Hurd's point is that just because it's a "horn" doesn't mean it's taking the full advantage of the horn loading.

[michael hurd]

Look at post # 58 again on that link. That is the measured FR of all boxes outside. ( they didn't get to do the THT with hatch cover on as it cooked itself before that could happen ) Without the hatch cover, the THT has much more low end than with the hatch cover.

Without the driver cover, the raw response was at least 11 db down @ 31.5 hz relative to it's highest level. The flattest box measured there was a JBL SRX718, a small ported unit of 8 cu ft external. Which one will sound good without eq?

To re-iterate what an amplifier does, it creates a voltage, not watts. To be able to swing + - 65 v, your amplifier needs to be able to develop 1kw into a 4 ohm load. The impedance from horn loading will be much higher than without, having multiple spikes. This means while the actual 'wattage' across the coil will be lower, the amplifier still has to be able to swing high voltages.

The point is that while a THT might be impressively loud from 40 hz +, that's a region that isn't hard to make anything get loud.

[psg]

Well, the numbers implied higher sensitivity at 40 Hz than at 50Hz. But anyways... My point is that I expect it will outperform anything I could have purchased for $1000 in Canada (roughly the price of parts + amplification + EQ, and I may not even need amplification for it), not that it will be better than anything out there. If you guys know different, I would liketo know what your commercially-available $1000 sub recomendation is.

[psg]

Look at post # 58 again on that link. That is the measured FR of all boxes outside. ( they didn't get to do the THT with hatch cover on as it cooked itself before that could happen ) Without the hatch cover, the THT has much more low end than with the hatch cover.

Without the driver cover, the raw response was at least 11 db down @ 31.5 hz relative to it's highest level. The flattest box measured there was a JBL SRX718, a small ported unit of 8 cu ft external. Which one will sound good without eq?

?

We sure aren't reading these the same way... I see the THT output at 31.5 Hz WAY higher (relative to its max) than any other sub on that graph. It may be 11 dB down, but most of the others aren't even on the chart by then. I don't care about flat to 200 Hz since I will be crossing this over at 80 Hz max (40 Hz for the mains and stereo, music, 60 Hz for the center and 80 Hz for the surrounds). Sure LFE content can go higher but I'm not too worried about how that sounds.

[superedge88]

Interesting conversation. I let audissey do the eq correction for my room, and it is known that audyssey gives the subwoofer a gradually rising bass response as you go into the lower hertz. I use a Dayton amp that is known to do 500 watts into a 4 ohm load continuously (who knows what it does in short bursts) I have my tuba crossed over at 60 hertz, because at the main listening position I sit only 3 feet away from the tuba and it is harder to localize the bass at 60 hertz. I'm quite happy with my tuba, if I want louder "cleaner" bass than what I have then I will just build another tuba.