So, here's my IR (light green), minimum phase IR (light grey) and step (dark green), measured from 1m. As you can see IR and minimum phase IR are practically identical. There is some pre-ringing in step response as a result of phase adjustments betwen speakers to avoid bass cancellation, but it is not audible.
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Revel F208 Tower Speaker Review
- Thread starter amirm
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So, here's my IR (light green), minimum phase IR (light grey) and step (dark green), measured from 1m. As you can see IR and minimum phase IR are practically identical. There is some pre-ringing in step response as a result of phase adjustments betwen speakers to avoid bass cancellation, but it is not audible.
Same thing measured from LP, 4m away from speakers. It, of course, looks worse, because reflections. So yes, the more refelections you have in your room the harder you will be able to notice the subtle effects of time domain corrections.
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Has anyone heard the “triple 8” ?All of the above
Actually, I was referring to the Revel specifications:
Salon2:
Crossover Frequencies Four-way, high-order acoustic response @150 Hz, 575 Hz, and 2.3 kHz
Low Frequency Extension -10 dB at 17 Hz -6 dB at 20 Hz -3 dB at 23 Hz
Sensitivity 86.4 dB
Studio2:
Crossover Frequencies Three-way, high-order acoustic response @ 230 Hz and 2 kHz
Low Frequency Extension -10 dB at 21 Hz -6 dB at 25 Hz -3 dB at 32 Hz
Sensitivity 87.7 dB SPL
F328Be:
Crossover frequencies 240Hz; 2.1kHz
Low-frequency extension 24Hz (-10dB); 26Hz (-6dB); 35Hz (-3dB)
Sensitivity (2.83V/1m) 91 dB
F228Be:
Crossover Frequencies 260Hz; 2.1kHz
Low-frequency extension: 23Hz (–10dB); 27Hz (–6dB); 31Hz (–3dB)
Sensitivity 90dB
F226Be:
Crossover frequencies 260Hz; 2.1kHz
Low-frequency extension 38Hz (–10dB); 44Hz (–6dB); 50Hz (–3dB)
Sensitivity 90 dB
In floor standing speakers, the Performa series requires half the power of the Ultima2.
That is not the whole story. The Salon2's dip below 4 ohms and I suspect that they are harder to drive.
If you don't drive them with an amplifier that remains linear under load and difficult phase angles they will not perform to specification.
Very few AVRs are tested into these loads and will not drive them well.
The Ultima2 have down-firing ports. The F328Be that is rear ported. The F208 and F228Be are front ported.
- Rich
I suspect that -3db spec is a typo?
It is odd but the website and manual are in agreeance.
Also, the 328Be recommended power is 50 watts less.
The 328 has a rear mounted port, so that is wrong. Perhaps the LFE specs are also wrong.
- Rich
vavan
Senior Member
wrong lfe specs for 228 again
Count the woofers. Measure the height.
Its fine looking graphs Qmuse and probably sound great, where we disagree is your impulse in my eyes deviate from textbook and you want to turn that problem to be a problem of method for time correction where i want it to be your speakers baked design or a user setting that little misuse or overcorrect the filter because we can or a not perfect calibrated measurement chain
proof is if we output IR on below responses and import them to REW and do the math over there we end up nather pre ringing from the repair that should not be there and therefor i mean dont blame prerinng to time correction method for excess phase but user settings or misuse of user settings or physical baked speaker system behavour or ones measurement chain, and going 100% active for a speaker system as mitchco often suggest can help if theres any time trouble build into a passive system and one want to correct perfect on excess phase.Its fine looking graphs Qmuse and probably sound great, where we disagree is your impulse in my eyes deviate from textbook and you want to turn that problem to be a problem of method for time correction where i want it to be your speakers baked design or a user setting that little misuse or overcorrect the filter because we can or a not perfect calibrated measurement chain
View attachment 64308
We were not talking about impulse response, but about pre-ringing in step response. My point explained here is that pre-ringing is an artificial artifact introduced by convolution engine processing certain types of FIR filters, and that type of artifact doesn't exist with any passive speaker no matter how bad designed it is. Which is totally understandable as there is nothing in passive speaker that can cause pre-ringing, as in order to get preringing a signal should start before the main signal started and that can be caused only with signal manipulation which passive crossover simply cannot do. Have you seen any passive speaker with pre-ringing artifact?
I don't see how the example you posted has anything to do with introducing pre-ringing in the context of phase correction. Here is a phase response of my left speaker. The "S" shaped artifact circled red has nothing to do with speaker's anechoic phase response but only with the position of the speaker in my room. My other speaker doesn't have such artifact in it's phase response. Still, it doesn't cause any pre-ringing by itself as I have shown in uncorrected step response posted before.
My point was that as soon as I start to apply filters with Q>=2 pre-ringing will occur, and to correct that S shape I would need at least 2 phase filters with Q much higher than 2.
And that was the only point of my initial post on that topic: pre-ringing doesn't exist with passive speakers but you can easilly introduce it when doing phase corrections with high Q filters, so it is not wise to chase pancake flat excess phase response as introducing pre-ringing would mean introducing audible artifacts which means much more damage than that is a benefit of flat excess phase.
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tuga
Major Contributor
Another set of measurements:
Here is a link to Revel spinorama data for Performa3, Performa Be and Ultima2 line:
https://speakerdata2034.blogspot.com/2019/03/spinorama-data-revel-ultima.html
- Rich
https://speakerdata2034.blogspot.com/2019/03/spinorama-data-revel-ultima.html
- Rich
Sorry, I am a new member and didn’t go through all 29 pages of this review but noted that the single wire connection shown in the opening post doesn’t reflect Revel’s recommendation. The upper high frequency posts as shown for my Revels are recommended in both owner manuals. Not sure how this difference would change the objective measurements.
It wouldn't.
tuga
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Please check the REW RTA settings, they should be RTA 1/48 Octave and not Spectrum.
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