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Multi-Way Conventional loudspeakers with crossovers

The POOR man's Tannoy DMT - AKA "The PM-DMT"
The POOR man's Tannoy DMT - AKA "The PM-DMT"
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Old 23rd October 2018, 08:54 PM   #151
wae is offline wae  Netherlands
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Quote:
Originally Posted by spladski View Post
The resonance frequency of the tweeter is a factor for the crossover. Input to the tweeter has to be well down at this point if the speaker is going to be driven hard. This is why I ended up with ~1.8KHz. Measurements picked up the resonance with the crossover in place. A DSP might be able to notch it out, which is preferable to steeper filters.
Hi spladski,

Did you measure that on the Tannoy 2036, or a different driver. Do you still have those measurements and are you willing to share? I do intend to use the DSP in the Hypex 3-way module.

kind regards,
Frans
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Old 23rd October 2018, 09:26 PM   #152
blanca12 is offline blanca12
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Behringer has brought out better and better products, seems hard to get rid of their past image.
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Old 24th October 2018, 03:24 AM   #153
spladski is offline spladski  United Kingdom
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The POOR man's Tannoy DMT - AKA "The PM-DMT"
Quote:
Originally Posted by wae View Post
Hi spladski,

Did you measure that on the Tannoy 2036, or a different driver. Do you still have those measurements and are you willing to share?
Frans
I don't have the individual measurements to hand. I managed to dig out the final measurement. You can clearly see the resonance at 900Hz. This was a passive xover and very hard work to achieve this level of performance. The microphone I was using was a button electret which couldn't be trusted entirely. Note the absence of any mid band suckout which can plague coaxials. Disregarding the one peak, it came out at +/- 1.5dB for most of the important mid range. Now I use B&K 4165 mic as I found that once a speaker gets to within +/-2dB, 0.5dB trims can be heard and need to be measured.

The peak does not manifest itself in a bad way. It actually makes drums sound more dynamic than they really are. No speaker is perfect and I have encountered some truly dreadful 'studio' class monitors.
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File Type: png Tannoy_Saturn.PNG (15.1 KB, 68 views)
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Old 25th October 2018, 10:39 PM   #154
spladski is offline spladski  United Kingdom
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The POOR man's Tannoy DMT - AKA "The PM-DMT"
As a follow up, I dug out some more info. The brochure for the NFM8 indicates 2.3KHz for the crossover, but the driver is listed as the 2025. It also states low order crossovers so this would explain the higher frequency.

Another point is the frequency response. The one I posted may not look as flat as people claim for other designs. It is a single measurement, not averaged. What it does indicate, is that with DSP +/- 1dB maybe possible.

In another thread someone asks what should be the design goal. Not all measurement methods produce the same results which complicates matters. The Saturn had a review with a frequency response plot. This showed mild midrange depression. However, when I measured it, the mid range depression was severe. So either my method differed from MLSSA which is commonly used, or Tannoy had a different crossover revision.
I don't have access to MLSSA, so cannot compare directly. However, it seems to me that MLSSA does not reveal all the gory details because it is an indirect method. I use gated sine wave which reveals edge diffraction effects from the drivers themselves, not only the cabinets. I also make measurements at less than 1 meter which accentuates defects.
Attached Images
File Type: png NFM8.PNG (32.6 KB, 42 views)
File Type: jpg Saturn S8LR.jpg (34.7 KB, 42 views)

Last edited by spladski; 25th October 2018 at 11:01 PM. Reason: Wrong picture
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Old 27th October 2018, 11:00 AM   #155
wae is offline wae  Netherlands
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Quote:
Originally Posted by spladski View Post
I don't have the individual measurements to hand. I managed to dig out the final measurement. You can clearly see the resonance at 900Hz. This was a passive xover and very hard work to achieve this level of performance. SNIP
Well, with a passive cross-over, keeping it +- 2dB is an achievement by itself.

Thanks for the info.

kind regards,

Frans
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Old 27th October 2018, 11:34 AM   #156
wae is offline wae  Netherlands
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Quote:
Originally Posted by spladski View Post
As a follow up, I dug out some more info. The brochure for the NFM8 indicates 2.3KHz for the crossover, but the driver is listed as the 2025. It also states low order crossovers so this would explain the higher frequency.
Correct, how-ever I have the Series II, which has a 2036 Driver and passive filter Second Order Low, First Order High @ 1700 Hz. There is a spreadsheet at the Tannoy Hilberink site I got the info from, which is consistent with my series II brochure.

Must be quit a different driver, also higher Pe (from 120 to 200 Watt).

The lowest cross-over I found, Tannoy used on DC's is 1000 Hz, highest 2500 Hz (on the the 2033 & 2041). They go all the way up from 1000, 1100, 1200 etc.


Quote:
Originally Posted by spladski View Post
Another point is the frequency response. The one I posted may not look as flat as people claim for other designs. It is a single measurement, not averaged. What it does indicate, is that with DSP +/- 1dB maybe possible.
Which is why a opted for only DSP versions. As a side note, maybe just as important, I don't have extensive knowledge on passive cross-overs just understand the basic principles.

Quote:
Originally Posted by spladski View Post
In another thread someone asks what should be the design goal.
These should become my "Studio Main monitors" for the project studio market. Meaning neutral response at high SPL levels (relative to the smaller control-room). VERY important conditions; LOW cost components that are commercially available, the speaker should come very close to "Top notch" like ATC, PMC and the likes, NO sub required.

Quote:
Originally Posted by spladski View Post
Not all measurement methods produce the same results which complicates matters. The Saturn had a review with a frequency response plot. This showed mild midrange depression. However, when I measured it, the mid range depression was severe. So either my method differed from MLSSA which is commonly used, or Tannoy had a different crossover revision.
I don't have access to MLSSA, so cannot compare directly. However, it seems to me that MLSSA does not reveal all the gory details because it is an indirect method. I use gated sine wave which reveals edge diffraction effects from the drivers themselves, not only the cabinets. I also make measurements at less than 1 meter which accentuates defects.
I will get some assistance in measuring, we will state the method used.

Kind regards,

Frans
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