BatPure 'Super-Tweeters'

[Bonky]

SuperTweeters

This is not for the pure subjectivists..

I have been experimenting with some ‘Batpure’ super-tweeters that seem to have garnered a lot of rave reviews in various forums.
(https://www.ebay.co.uk/itm/New-TAKE-T-BATPURE-pair-Super-Tweeter-Sound-quality-improvement-F-S-w-tracking/253826017843?epid=1566077164&hash=item3b1935aa33:g:a0MAAOSwWo5bfJLq)

So I decided to do some tests. Subjectively, (setting up the null hypothesis), I couldn’t hear any difference - or if there was it was minor. I’m 70yr old so my ‘top-end’ is obviously limited anyway, but I was curious so see if there were objective tests. Other people have subjectively experienced, paradoxically, a better lower and mid- range (!) - possibly, so some have argued, as the addition of the super tweeters alters the impedance characteristics of the main drivers.

Apparatus:
Mac laptop. Minidsp UMIK1 microphone (calibrated). REW software (free). ((https://www.roomeqwizard.com))


Fed from headphone socket on the Mac laptop to a Schitt pre-amp and then a WD KEL84 valve amp.
The super tweeters are mounted in separate boxes that sit atop my Living Voice speakers (see pic)

I am NOT an expert in the software- I just used a simple guide (https://www.minidsp.com/applications/acoustic-measurements/umik-1-setup-with-rew)

These are the results: at first I thought…as expected…no difference - but then when I utilised overlays there were subtle differences. The test was repeated a second time. (Results not shown as only 5 pics can be uploaded per 'message' -but they showed the same results. PM me if you wish me to Email them to you)


I’ll let others pass comments…and yes…I know… ‘use your ears’ - a mantra that I have already signed-up to, but I do find objective measurements interesting (gratifying if they support one’s prejudices; annoying if they don’t (but still interesting though)).

[CageyH]

You need to try a different microphone.

The microphone you have has the following characteristics - Frequency response: 20 Hz - 20kHz +/-1dB with calibration loaded

[Lawrence001]

Individual microphones might be within that spec but I wouldn't expect a given microphone to change its spec between observations, so I think the comparison graphs are valid. If not, then a few repeated observations with averages would confirm or not.

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[CageyH]

You are missing the point.
Super tweeters operate above 20KHz, so with a low cut off level why would you see if they do anything on a graph? It is like trying to measure absolute zero with a thermometer that only goes to 0 degrees Celsius.

[CageyH]

The Batpure starts to operate at 20KHz, and apparently goes up to 150KHz.

[sq225917]

You can't measure those superyweeter with that mic, you need one with a response up to 40khz

[sq225917]

Just noticed you're 70, stop wasting your money on supertweeters. You'll struggle to hear 14khz never mind 20khz.

[Bonky]

Hi,

There are 2 points I'd like to make:
1. I agree that the microphone cannot measure the HF output of the BatPure above 20kHz.
2. BUT it can measure the somewhat paradoxical theory that the use of a super tweeter can have an effect on the frequency graphs of the main drivers (see first post).

[walpurgis]

Just noticed you're 70, stop wasting your money on supertweeters. You'll struggle to hear 14khz never mind 20khz.

Is there a misconception here? It's not the audible output from the supertweeter that is listened to, it's the effect it has on the overall sound. I can hear whether a supertweeter is in circuit or not and I'm 70. I've experimented with many supertweeters rolling in correctly above the output from the main tweeter and can always hear their effect.

[hifi_dave]

Exactly.

Do you need to spend large amounts on a Super Tweeter ? I used to add a £5 Motorola Super Tweeter to all manner of speakers back in the 90s and it worked very well.

[struth]

Is there a misconception here? It's not the audible output from the supertweeter that is listened to, it's the effect it has on the overall sound. I can hear whether a supertweeter is in circuit or not and I'm 70. I've experimented with many supertweeters rolling in correctly above the output from the main tweeter and can always hear their effect.

yup, you feel it, and it can have, or appears to have an effect on bass too. no idea why, but guessing its via skin

[walpurgis]

Exactly.

Do you need to spend large amounts on a Super Tweeter ?

Dunno. Some are very expensive.

I've used many different tweeters for this, but my favourite was the Celestion HF2000, which worked very well. Better even than Decca ribbons.

[sq225917]

The output of the supertweeter could be modulating the air from the other drivers, much more likely however that it's effects as a parallel filter to the rest of the xo is what we actually hear.

[Lawrence001]

You are missing the point.
Super tweeters operate above 20KHz, so with a low cut off level why would you see if they do anything on a graph? It is like trying to measure absolute zero with a thermometer that only goes to 0 degrees Celsius.Ah I was referring to the overlay below 20khz, I thought you meant the difference was due to the range in the spec. I wasn't looking at the chart over 20khz, although I don't think the mic would become wildly inaccurate at 21khz, they probably didn't quote the range there as they didn't think anyone would want to use it that high being ostensibly "inaudible".

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[WESTLOWER]

I have some super tweeters in the system at the moment and can’t put my finger on what they do..
They do seem to give something to the overall presentation, but I can’t articulate what that actually is..
I’ve taken them out (covered up with cushions) and I keep going back to having them in.
I know Paul coupe who designed my speakers and crossovers wouldn’t advise having them in, which begs the question, are they actually messing the balance up? But I quite like them. Hmmm

[sq225917]

1. What's the roll-off of the supertweeters? Is the bottom end in the audible range?
2. What's the max power handling of the super tweeters?
3. What sort of electrical load do they present?

Chances are with most of them the bottom end overlaps well below 20khz. The Batpures AIUI don't they're just 20khz+, they have measly output power, not enough to modulate anything, so maybe it's the load they provide that causes any effect that may exist with them. They certainly don't operate up high enough for you to feel it on your skin A'la radio frequencies.

[walpurgis]

1/ The bottom end of a supertweeter's output should be above audiblity in most cases if implemented properly. Using one above a Celestion HF1300 tweeter's output is an exception, as the HF1300 cuts off very steeply at its top at around 13.5 kHz and many people would hear the lower output from a supertweeter used here.

2/ Depends on the power rating of the supertweeter, but it doesn't need to be much, as the energy at higher frequencies is lower.

3/ Depends on the impedance of the supertweeter, but used in parallel as normal most would not cause a problem load.

[Lawrence001]

I've bought these off Steve at Electric Beach, liked the look of the grilles, now I just need to find a couple of boxes to put them in. Any ideas? I imagine some of those small Indian jewellery boxes look nice and are relatively cheap. Preferably without all that applied metal decoration.

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F 332789970789


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[Mr.Ian]

I played about with some radio shack / tandy super tweeters, first order 6db crossover, and despite changing the cap to 1uf they were working down to at least 5k. (REW & calibrated mic)

I have had them out of system for ages now but have just ordered some .33uf caps to see if I can push the crossover point up higher, the goal being to sense a difference without actually hearing one.

A steeper crossover is of course another option.

Interestingly I have also been looking at target frequency response curves (https://www.innerfidelity.com/content/harman-tweaks-its-headphone-target-response), which sort of questions if we actually need super tweeters or indeed anything much above 15kz

[walpurgis]

I played about with some radio shack / tandy super tweeters, first order 6db crossover, and despite changing the cap to 1uf they were working down to at least 5k.

I'm not surprised. 1uF is too big with an 8 ohm unit. I experiment with values depending on which tweeter is being used and generally end up with capacitors of around 0.22 uF to 0.1 uF.

[Mr.Ian]

thanks for the head up, I will order some smaller ones

[wee tee cee]

I had good results with batpure STs on my 57s.

Even better with my Electric beach frugels.

I found mounting them on the rear and firing vertically to be best.

As Grant mentioned, they do something nice to the bass....dont ask me why.

My son runs the frugels with them...his 24year old ears really like what they do.