They greatly improved the response of that driver, good job.
Cone suspension surround is stiffer you mean. Yes it boosts low end in the case of a woofer of 15 inches, duh!
Your example is irrelevant because : in the case of a mid range of 6' it enables the driver to have better control of resonances at high power in the 1khz range AND it greatly reduces SENSITIVITY.
This is the opposite of what happens in a WOOFER if you have a stiffer suspension. Totally different drivers!!!
AND in some midrange stiffer suspensions will increase sensitivity, Cms is just one multiplied parameter...
You cannot generalize on Cms because it is multiplied, you have to take in account other parameters to know the outcome.
Cone suspension surround is stiffer you mean. Yes it boosts low end in the case of a woofer of 15 inches, duh!
Your example is irrelevant because : in the case of a mid range of 6' it enables the driver to have better control of resonances at high power in the 1khz range AND it greatly reduces SENSITIVITY.
This is the opposite of what happens in a WOOFER if you have a stiffer suspension. Totally different drivers!!!
AND in some midrange stiffer suspensions will increase sensitivity, Cms is just one multiplied parameter...
You cannot generalize on Cms because it is multiplied, you have to take in account other parameters to know the outcome.
Last edited:
You are right, the discussion is pointless but because of other things: You still didn't say how you wanted to use the driver nor the partners, xo f, sub nor active or passive. In the latter case both of your tweeters probably won't have a high enough sensitivity for 1/4 of the drivers. Besides that, you wanted 'true frequency response'. Well, the D2904 does not deliver on that, the 6dB steep step at 5k isn't easy to handle, passive you won't get it really linear and get the energy bilance in the room clean at the same time since it diverts in a huge manner under angles. Additionally, the baffle dimensions will change the frequency response of both the tweeter and the mid driver, you'll have to build some kind of compensation for that, search for "baffle step" and "edge diffraction".
Unless you are telling what you're planning, nobody will be able to help you.
A: "What's the best car? These have 350, 400, 650 and 800 horses"
B: "Is the 800hp a Ferrari? Ferrari are the best!"
A: "But it can't go up the hill on my farm"
B: "Is it the Ferrari? If it isn't, the 1st is probably the Ford truck with a bed and will be better on your farm"
A: "But it guzzles too much gas! And it doesn't fit in my garage!"
B: ...
A: "And I can't get my 5 children, the wife and the 3 dogs in it"
B: "What do you want to do with it?"
A: "Tell me, WHICH is the best car? #1 will perform awfully on the racetrack!"
B: ...
.. do you see the problem?
Unless you are telling what you're planning, nobody will be able to help you.
A: "What's the best car? These have 350, 400, 650 and 800 horses"
B: "Is the 800hp a Ferrari? Ferrari are the best!"
A: "But it can't go up the hill on my farm"
B: "Is it the Ferrari? If it isn't, the 1st is probably the Ford truck with a bed and will be better on your farm"
A: "But it guzzles too much gas! And it doesn't fit in my garage!"
B: ...
A: "And I can't get my 5 children, the wife and the 3 dogs in it"
B: "What do you want to do with it?"
A: "Tell me, WHICH is the best car? #1 will perform awfully on the racetrack!"
B: ...
.. do you see the problem?
ICG don't get angry, I appreciate your common sense.
I was referring to this tweeter Revelator – Scan-Speak A/S
I just want to choose a good driver after I will build the optimal baffle and enclosure.
I already set my mind on something, but the Simulators are far from the reality, and my measurement are Not perfect! I measure with a calibrated microphone but in my Room!!! and my understanding of XO is very basic, Only time is on my side , I can take 5 years to design the XO after but I want to make sure most big mistakes are not being done.
I want a separate enclosure for midrange and tweeter and bass, to align after the driver to get impulse response in time.
I was referring to this tweeter Revelator – Scan-Speak A/S
I just want to choose a good driver after I will build the optimal baffle and enclosure.
I already set my mind on something, but the Simulators are far from the reality, and my measurement are Not perfect! I measure with a calibrated microphone but in my Room!!! and my understanding of XO is very basic, Only time is on my side , I can take 5 years to design the XO after but I want to make sure most big mistakes are not being done.
I want a separate enclosure for midrange and tweeter and bass, to align after the driver to get impulse response in time.
The measurements will never be perfect. No matter what you do, you'll have to chose the one or other compromise. That compromise will always apply, no matter what you chose on baffle width, drivers or crossover points, you'll never get everything right. Chose the best comprimise for you. The crossover (or setup) changes more of the sound than the drivers itself. Simulators nowadays are amazingly accurate - if you feed the correct measurements and data. You can create a speaker in boxsim or other simualtions that are 95-99,9% correct or 80-10% if you use it wrong.
I'm not angry, I'm disappoointed because that's another 'my ideal is xyz, confirm it without knowing it' thread.
Good luck with your endeavours.
I'm not angry, I'm disappoointed because that's another 'my ideal is xyz, confirm it without knowing it' thread.
Good luck with your endeavours.
Good. Tell us what it is, and why. Then we might be able to help you.
Do you need a car to haul a big family or to win Paris-Dakar?
Guys, I assume you know already better than me. I am to my #4 set of diy speakers, not much.
I built 2 OB 3 ways with different woofers, 1 MTM and 1 with passive radiator.
I am hesitating between the isophon P170/30 and the scan speak 18M 8 ohm, they both have after correct enclosure and XO the same response.
I built 2 OB 3 ways with different woofers, 1 MTM and 1 with passive radiator.
I am hesitating between the isophon P170/30 and the scan speak 18M 8 ohm, they both have after correct enclosure and XO the same response.
There you have it. The sound from the Isophon P170/30 is very different from the Scan-Speak 18M/4631T, they couldn't be more different.
The Isophon sounds more open, lively but got much higher distortion, resonances and is less linear. A construction around 40 years old, no ventilation, steel stamped basket. The Scan Speak is high-tech, aerodynamic cast basket, membrane slit and re-filled, vented spider and pole core, titan VC former, high tech suspension and foam surround which is even coated and non-dramatic fall off. Can take 5 times the power of the Isophon. It is neutral, almost resonance free (except for a well dampend one at ~900Hz) and very linear up to 1000Hz, after that you'll have to EQ it in some way.
They will definitely not have the same response.
The Isophon sounds more open, lively but got much higher distortion, resonances and is less linear. A construction around 40 years old, no ventilation, steel stamped basket. The Scan Speak is high-tech, aerodynamic cast basket, membrane slit and re-filled, vented spider and pole core, titan VC former, high tech suspension and foam surround which is even coated and non-dramatic fall off. Can take 5 times the power of the Isophon. It is neutral, almost resonance free (except for a well dampend one at ~900Hz) and very linear up to 1000Hz, after that you'll have to EQ it in some way.
They will definitely not have the same response.
Well the OP asked us to choose a driver based solely on T/S parameters so I'd say this discussion is relevant. I respect your knowledge although I'm still a bit unsure how this applies to efficiency.
Thank you Earl. As expected the response between 120-2K is significantly reduced.
Not really but typically a woofer is used in freq closer to it's resonant freq. How a driver responds around FS and away from FS is totally different, correct.
I'd say go with the SS, these people seem to know what they are doing.
Last edited:
Yes. You sounded like a woofer isn't used at or below the fs and that's wrong.
Practically every vented enclosure uses the woofer below the fs (some even a lot deeper) and sealed enclosures still reproduce sound below the fs.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.