TH118vsSB1000z

B

Brandon Wright

Freshman
Sep 19, 2012
75
2
8
As promised, I had some time today to make some quick and dirty measurements of the TH118 and an SB1000z.

Now, take these for what they are worth. I am an amateur when it comes to measurements, this was in the shop (it was too cold and windy to go outside), and it was done with a hundred dollar microphone. That being said, it should provide for a good enough relative comparison. Mic position was roughly 2 meters away directly between the two subs with the unused sub shorted and simply moving the speaker cable back and forth. Processing was simply a 25hz hpf and an 80hz lpf.
TH118vSb1000.jpg

My ears agree with what the trace shows. That increased sensitivity from 40hz to 80hz is definitely noticeable. I was surprised to see that the SB1000 had a bit of an advantage down low. However, while the sb1000 may be putting out more energy, the TH118 sounds way cleaner doing it. The subjective perception of SQ is interesting. While the TH118 is definitely more accurate, many of the guys preferred the "crunchy" sound of the sb1000. Probably because that is what they are used to.

Morals of the story:
1. Both are good subs and I have no problems mixing on either of them.

2. Price differences are negligible.

3. The TH118's provide a better stacking surface for the purposes of my 650 rig.

4. However, for big shows, you don't have to explain to a BE what an sb1000 is. The only question is: how big of a pile would you like?

Okay, rip away. 8)~8-)~:cool:
 
Re: TH118vsSB1000z

Oh and I forgot to add that we had 24 brand new EV xsubs in the shop, and let's just say they were the definite loser in this test. I thought I saved a trace, but alas it's not there. Lets just say it was pathetic when we switched to them from the TH118 and sb1000 while listening to Thanks to You by Boz Scaggs. 8O~8-O~:shock: Oh well, the high profile customers get whatever it is they think they want...........:roll:
 
Re: TH118vsSB1000z

It would be best to show the response without any processing-high or low pass filters.

Yeah they won't be used that way-but then you get a better idea "overall" of what is happening.
 
Re: TH118vsSB1000z

It looks like you some reflective surfaces nearby-and the distance from each of the cabinets to the surface would be different if they are in different locations-even slightly different as the other cabinet would affect the "path".

Specifically around 90Hz (as indicated by the notch in the response and the phase shift).

It gets kinda hard to make everything equal.

Just like when listening to full range speakers side by side. In many cases (unless you are in a large room or outside) they will sound different-because of the different reflection paths due to the physical location of the cabinet.

Something else to consider is the measurement distance. With drivers that are loaded very differently-measuring to close can affect what the "real" effect of the speaker is. That is the reason it is best to measure a lot further away and "back calculate" to get an idea of how the cabinets will response in a real room. Yeah the differences of the close measurement are "real" at least for that measurement position. But (at least in my opinion) the measurements (at least on a spec sheet) should give real information about how the loudspeaker performs so that its performance can be predicted in a larger space.

I realize you were not in the best of conditions-and we all deal with that. I was just pointing out some "little things" that can affect what the measurement looks like.
 
Re: TH118vsSB1000z

Brandon Wright said:
Oh and I forgot to add that we had 24 brand new EV xsubs in the shop, and let's just say they were the definite loser in this test. I thought I saved a trace, but alas it's not there. Lets just say it was pathetic when we switched to them from the TH118 and sb1000 while listening to Thanks to You by Boz Scaggs. 8O~8-O~:shock: Oh well, the high profile customers get whatever it is they think they want...........:roll:
Click to expand...

That's odd. I've always found the EV x-subs to be very capable.





Evan
 
Re: TH118vsSB1000z

Brandon Wright said:
The subjective perception of SQ is interesting. While the TH118 is definitely more accurate, many of the guys preferred the "crunchy" sound of the sb1000. Probably because that is what they are used to.

Morals of the story:
1. Both are good subs and I have no problems mixing on either of them.

2. Price differences are negligible.

3. The TH118's provide a better stacking surface for the purposes of my 650 rig.

4. However, for big shows, you don't have to explain to a BE what an sb1000 is. The only question is: how big of a pile would you like?

Okay, rip away. 8)~8-)~:cool:
Click to expand...
Brandon,

Thanks, you finally have done what I hoped Ivan Beaver would have done almost exactly two years ago, but has been too busy to do!
I had questioned TEF measurements(as used by DSL and others)in this post:
http://soundforums.net/varsity/957-why-do-tef-systems-read-3-5-db-high.html

Some details about the comparison of the two cabinets:
The SB 1000Zp uses 2 volt for a 102 dB half space sensitivity, the TH-118 2.83 volts for 108 dB sensitivity.
Reducing the TH-118 sensitivity by 3 dB to account for the voltage difference leaves a 3 dB difference on paper, and rather different response curves.

Your measurements indicate that DSL's and EAW's published sensitivity ratings, though using quite different measurement technique, are still remarkably close, within 1 dB.

One thing sensitivity ratings won't show is distortion, the speaker used in the TH-118 has a lot more Xmax than those used in the SB 1000, and the SB 1000 speakers have more than the EVX180B speakers used in the more sensitive EV Xsubs that you found "pathetic" by comparison.

Even though the three subs all have similar sensitivity, the EVX180B with only 6.4mm X max will "run out of steam" while adding lots of distortion at around 8 dB less output than the 15mm Xmax BC18SW115-4 used in the DSL TH-118.

At 40 Hz, a difference of 8 dB sounds twice as loud to your ears, though adding lots of distortion by driving speakers above Xmax can make the inferior speaker sound louder, since our hearing is more sensitive to upper harmonics than the fundamental frequencies.

As evidenced by the popularity of cabinets using a driver design far older than many who post here, low frequency distortion is still well accepted by many mixers of pop music.

Art
 

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Re: TH118vsSB1000z

Brandon Wright said:
Mic position was roughly 2 meters away directly between the two subs with the unused sub shorted and simply moving the speaker cable back and forth.
Click to expand...

Sorry if this is more of a JV question, but I often wonder when reading about such comparisons of different cabinets like this, why is there no apparent issue of unused box(es) acting as a passive radiator?

I note mention of shorting the unused cab, but I didn't realise this electrical technique fully resolved the acoustic potential of the unused drivers and box tuning, preventing them affecting the measured result from the driven cabinet :?~:-?~:???:
 
Re: TH118vsSB1000z

Guy Graham said:
Sorry if this is more of a JV question, but I often wonder when reading about such comparisons of different cabinets like this, why is there no apparent issue of unused box(es) acting as a passive radiator?

I note mention of shorting the unused cab, but I didn't realise this electrical technique fully resolved the acoustic potential of the unused drivers and box tuning, preventing them affecting the measured result from the driven cabinet :?~:-?~:???:
Click to expand...
For a passive radiator to radiate passively, it has to move.
Shorting the speaker effectively "puts the brakes" on the cones, eliminating the peaks and dips that are apparent if they are left unshorted. Both cabinets use strong motors that are very effective in stopping cone movement, low BL speakers as used in some home stereo cabinets would be less so.
I have posted some results on DIY audio on the subject, unfortunately seem to have deleted the screenshots after posting, but the shorted cabinet basically became a box.

The adjacent shorted cabinet does provide a larger frontal area than a single, which makes for more forward directivity, which in Brandon's test would increase the output level of both cabinets.
The slightly smaller frontal area of the SB1000 would derive slightly more benefit from the larger frontal area of the TH-118, but the difference would be probably less than .5 dB out of a 1.5 dB gain.

Ideally, the tests would have been outdoors at a greater distance(like 10 meters) with no objects within a couple wavelengths at the lowest frequency of interest (like 25 meters) but you gets what you gets.

At least this test was a lot more fair than at the DSL shootout where Brandon realized later that one of the SB1000 cones was undriven, that makes an adjacent un-shorted sub look like nothing, an example using a different band pass cabinet here:

http://soundforums.net/attachments/...4-danley-gainesville-ga-bowtievarious.png.att

The upper white trace is the BP sub "normal" (both cones operational), the purple shows one side undriven, green one side undriven and shorted.
The differences are not subtle.

Art
 
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Re: TH118vsSB1000z

Guy Graham said:


Sorry if this is more of a JV question, but I often wonder when reading about such comparisons of different cabinets like this, why is there no apparent issue of unused box(es) acting as a passive radiator?

I note mention of shorting the unused cab, but I didn't realise this electrical technique fully resolved the acoustic potential of the unused drivers and box tuning, preventing them affecting the measured result from the driven cabinet :?~:-?~:???:
Click to expand...

It was definitely a quick and dirty comparison. It was too cold at that time to go outside, at least as a far as I was concerned. The intended purpose that day was more of a listening session with some impromptu measurements. Maybe if I get some time this spring, before we get too busy, I'll drag our whole lineup of subs (sb1000, th118, mtl4, sb850, xsub, 4719) outside and do it better. An acoustically large space wont be a problem as there is flat land for about 20 miles in each direction outside the shop. No promises though. :D~:-D~:grin:
 
Re: TH118vsSB1000z

Brandon Wright said:
Maybe if I get some time this spring, before we get too busy, I'll drag our whole lineup of subs (sb1000, th118, mtl4, sb850, xsub, 4719) outside and do it better. An acoustically large space wont be a problem as there is flat land for about 20 miles in each direction outside the shop. No promises though. :D~:-D~:grin:
Click to expand...
Brandon,

That would be a real interesting line up!

I'd still be very interested in seeing some off axis tests between any of the bass reflex and the TH-118.
In my tests, tapped horns had more forward directivity than front loaded horns or bass reflex with similar frontal area, but proximity to buildings affected the results too much to give more than a general outcome.

With the space you have available, low frequency directivity would be easy to measure, and the difference can be quite surprising even as low as 60 Hz.

Art
 
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