Of course! Providing you are going to have the drivers operating at 1-watt at all times. In Pro Audio, 1-watt is a starting reference point nothing more. One should not calculate figures unless they are 100% certain that the drivers will withstand more power when faced with wattage higher than 1 watt.
That can only be answered by literally testing the drivers until they fail. Once that occurs, you record the highest SPL measured before thermal/mechanical breakdown. If you are not doing the above it is merely guesswork or estimate. It is just like a loudspeaker offering an 8/4-ohm Nominal load. It does not mean the driver will reside @ 8 ohms at all times within 20 - 20,000 kHz. There is a variability, which comes into play so you use the 8/4-ohm nominal load as an estimate.
Surely, you don’t believe Speaker Simulator results are embedded in stone do you? Simulators are only good as the numbers you dial in. If the numbers are not what they are said to be, the results in the simulators will not be 100% accurate. This is why real world tests are performed and preferred by many pro audio soundmen.
If that is good enough for you, it is good enough for you. That is not good enough for me since he has designed the keystone. This is why I keep saying bring the box to a subwoofer shootout in which it will be compared to other pro audio subwoofers in a room, or field in which, other sound men can listen and draw to their own conclusion on its performance in an unbiased manner.
OMNIFEX,
In your previous post you did not give the proper model number for the Phoenix PX2181, you called it an EV 2181, which is not a valid EV model #, so I could not find specifications.
Closest thing I found using the EVX180B was the EV QRX-218S, the specs of which I listed.
Now that you have given me the proper model number your wish is my command.
Per your request, the Keystone compared the Phoenix 2181 are below, "0" on the Keystone measurement is 100 dB.
The EVPX2181 uses different drivers and cabinet design than the MTL 1X, and has a much improved response, though it is larger and has less output potential than the EV QRX-218S.
I have not found TS parameters for the DVX3180 drivers used in the EVPX2181, but having lesser power handling, lets assume a similar or slightly less excursion capability until proven otherwise.
So now, the line up for sensitivity, excursion and power looks like this:
EV QRX-218S 100 dB @40 Hz, 105 dB @100 Hz (6.4mm Xmax) 1200 watts
EVPX2181 95 dB @40Hz, 105 @100 Hz (Xmax unknown, probably <6.4mm)1000 watts
Keystone 98 dB @40 Hz, 103 dB @ 100 Hz (14mm Xmax, 16mm Xvar)1700 watts
EV MTL-1X 83 dB @40 Hz, 100 dB @ 100 Hz (6.4mm) 1200 watts
JBL SRX728 96 dB @40 Hz, 99 dB @100 Hz (8mm Xmax) 1600 watts
Doubling power up to reaching Xmax allows +3 dB untill the voice coils heat up and power compression sets in.
Doubling Xmax allows 6 dB more output.
As is obvious to any one that has been to, or looked at the results of a sub shootout, (which I have conducted many times), a sub with the same sensitivity but higher Xmax is louder when given more power.
Subs will in general "flap" and distort when hit with power much below F3 or pushed above Xmax in their usable pass band.
Subs pushed above their AES power rating generally suffer from thermal compression, more power does not make them louder, and eventually burn up.
Using the above observations and some common sense, it does not take a rocket scientist to predict the outcome of a high power shootout for the above subs, it would look like this:
1) Keystone
2) EV QRX-218S (slightly louder lows and softer top at low power levels, above 1200 watts Keystone takes over at 40 Hz)
3)JBL SRX728 (+3 at 40Hz and below, EVPX2181 + 6 in the top end)
4) EV MTL-1X (- 13 the low end, -5 dB in the top )
Cheers,
Art
I would have thought after 7 pages you would have figured out what I am requesting.
So let me state exactly what I am and am not requesting
What I am requesting
One Chart (TEF, AP, or CLIO) showing your Keystone box with an Electrovoice MTL 1X or Electrovoice Phoenix 2181
For example:
What I am not requesting
JBL Comparisons
EV Comparisons with the Exception to the MTL 1X or Phoenix 2181
1-watt/1metre charts from the manufacture
Xmax estimates
Simulator charts (Horn Response, Bass Box Pro, WinISD, etc)
If you cannot provide a chart as the one listed above, bring your box to a subwoofer shootout. It will not only give many the opportunity to hear your creation, you will have a TEF, AP or CLIO chart which will compare your box to the other contenders present.
Cheers!
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Although I will say, Mr. Welter did provide a fairly good virtual shootout with albeit limited information. I would not expect any substantial "surprises" in a real shootout from what we know already.
Cheers!
"Question: Hybrid reflex horn (large chamber relatively short flared port) in Push Pull, I wonder how small the effective distance between the drivers would need to be to make things "right." "
Similar, but not the same as your request.
This is a mod to a vented LaScala, with the single 15 being replaced by a quad 8 in push-pull.
It sounds like it has much more deep bass than the 15, but the measurements do not show it. It must be the reduction in distortion from the push-pull mounting of the drivers at work here. The 8's are SEAS 4Ω with a rubber surround, wired in series-parallel. An Electro-Voice Interface A equalizer is used, and the pair of 4" ports are 7.5" deep and face out the back of the enclosed top box (mids and HF). Total back volume is about 4.8 cu ft, the small front horn on the LaScala has about a 90hz taper rate.
This is one of those things you have to hear to believe.
Similar, but not the same as your request.
This is a mod to a vented LaScala, with the single 15 being replaced by a quad 8 in push-pull.
It sounds like it has much more deep bass than the 15, but the measurements do not show it. It must be the reduction in distortion from the push-pull mounting of the drivers at work here. The 8's are SEAS 4Ω with a rubber surround, wired in series-parallel. An Electro-Voice Interface A equalizer is used, and the pair of 4" ports are 7.5" deep and face out the back of the enclosed top box (mids and HF). Total back volume is about 4.8 cu ft, the small front horn on the LaScala has about a 90hz taper rate.
This is one of those things you have to hear to believe.
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