Hey man thanks for the advice, its really helpful.
The Ultimax has a sensitivity of 88 dB and RMS 1,000. It reaches its limits at 118 dB. The B&C Sub has a sensitivity of 97 dB @ RMs 1,000 and reaches its limit at 127 dB, this is the SPL I'm more looking for.
I will check out the simulation software and see what I can gather from that; I didn't know excursion limits can actually have an effect on how loud a driver goes, it was my amateur understanding that a driver will go as loud as it's RMS coupled with their efficiency allowed. Will do some research on this.
This is also new to me, didn't know the size of the enclosure also plays a part at what level of power a driver reaches its excursion limits. Anyone care to shed some light on this?
I'm looking to cap my budget at anywhere around 2K, can't afford 4K right now.
Are you suggesting that I only need the one 12" midbass without the 1" compression drive as recommended by LineSource?
Would the Coaxial give better performance vs the econowave style?
Again thanks for the advice.
Thanks for the post.
Does any music goes below 40Hz? Or is below 40Hz more for movies and such?
I want to use this in the home while at the same time be ready to take it in a room with 100-150 persons and pump music out that would motivate them to dance. That's the best way I can describe it.
Most rock and natural instruments won't have much down there but electronic music can have some lower freq. But yes, typically stuff below that would be more LFE for movies and TV.
Any time you're designing a sub you'll typically have to come to a compromise between low freq extension and SPL.
Your understanding is mostly correct. The exception is bass. At low frequencies loudness is limited by the drivers stroke; the amount of air it can displace. This is simply cone area multiplied by Xmax.
If you play with a good simulator, this will become clear.
No. That was my mistake. I misread your post 13. I thought you were planning to use 2 x 12" midbass drivers per box.
Nope / depends on the application.
The econowave should be superior in some ways. It seems to be a good horn, and good value. Their selling point is their wide and even coverage - which works well in a large space (the 100-150 people scenario).
Coaxials can be better when you want a cabinet with minimal face area, or for listening at close distances. Using a coaxial locks in many of your design decisions, which might be a good thing.
This site has some 15" coaxials that are excellent value.
Speaker Clearance
P AUDIO BM15CXA
15" Co-Ax Speaker,
350 Watts RMS, 40-18kHz
8 Ohms, 101dB Sensitivity
Sale Price: $99.99
I've got some similar drivers at home (BM15CXHB) that I've been using for about 10 years. They are pretty good as Hi Fi speakers, are robust, and can go stupidly loud.
Before they became my living room speakers, I used them in a small factory. One 15" coaxial easily kept up with a quad of 15" bass drivers, in a large concrete enclosure (they were built into the structure, corner loaded, so no boundary losses).
I consider $100 to be crazy good value for something from the same 'family'.
Yea, its seems we have to settle for whichever one best suits our need. I'm gonna go with SPL over lower bass.
Thanks
Hey Chris, my desired SPL is around 120 dB; the distance is not fixed, I'm guessing a medium sized room that can fit 100-150 person. Dancing levels.
Thanks for the post.
I've tried Hornsrep and I'm now more confused, Cms, Vrc,Lrc, etc; don't really know what these mean or represent. The more I try to research them the more confused I'm get with all these numbers and calculations. Even when I did enter in some of the parameters I lifted from the driver specs sheet, I can't interpret the calculated data from Hornsrep.
You know how loud that is? Equivalent to a big thunderclap, a jet plane take-of at 60 meters, or front row seats at a big rock concert. I would not want to be in that room for a long time... for some dancing I think 100dB might be more comfortable...
Also note that to play only 10dB louder, you'll need 10 times more power with the same speakers (if they can physically cope). It quickly adds up.
If you want to do some simulations, try WinISD (pro) instead. It is much easier than Hornresp and has much less of a learning curve.
See, this is why this forum is so helpful. I read somewhere 120 bB was loud enough to entertain but didn't understand how loud it really was. Thanks a lot for clarifying that.
I will check WinSd. Thanks
The first picture shows how I threw the data from here:
B&C 18RBX100 is a high power 18" subwoofer for speaker subwoofer systems- B&C 18RBX100 Speakers - B&C 18RBX100 18" high power speaker for speaker subwoofer systems has an xmax of 10.0mm. B&C 18RBX100 high power speakers available now.
...into Hornresp. This is 100 watts into a sealed box in half space, giving 115dB at 1 metre, with 7mm displacement.
The second image shows the equaliser wizard in Hornresp. On the bottom left is as dropdown that lets you flick between different views, e.g. Power and Displacement.
The displacement window shows that, for this setup, this is the maximum amount of eq you could use. In this configuration, it will hit Xmax at 40Hz / 115dB.
...so a 500 watt amplifier would be enough to hit Xmax with this configuration.
To simulate a different driver:
1) Use the ADD button in Hornresp
2) Fill in the 7 boxes: SD, Cms, Mmd, Re, Bl, Rms, Le
Directly copy all the numbers that are stated
Any numbers that are not stated, just double-click in the cell, and Hornresp will prompt you on how to calculate them.
3) Double-click the Eg box at the top, input the wattage and the Re of the driver.
4) Hit calculate
5) Use F4 to compare the two speakers' responses
...and play around from there to work out what the trade-offs are.
Attachments
Agreed: this is too loud.
However, 120dB at 1m does not mean the dancer hears 120dB, if they are in a room that's big enough for 100-150 people.
Every doubling of distance is -6dB (if in free field, with no reflections), so if you are ~10m back from the speakers, the volume is approximately 20dB lower.
If a system is capable of playing 120 dB peak the achievable average SPL will be lower. The more dynamic the music is - the lower the average SPL for a given peak SPL capability. If the music is bass-heavy this might be even lower (although sometimes more annoying to neighbours).
I have records that reach comfortable concert levels if I drive my amps just below clipping. There are others that drive average listeners out of the room quickly if turned up just below clipping.
Regards
Charles
I have records that reach comfortable concert levels if I drive my amps just below clipping. There are others that drive average listeners out of the room quickly if turned up just below clipping.
Regards
Charles
Agreed, but he did not specify any listening distance, so I assumed in-room
Anyway, If we compare the B&C and the Ultimax, you'll see that the B&C will go louder above 28 Hz (we must then compare the B&C in BR and the Ultimax in a closed enclosure to get a decent frequency response). From 50Hz on the difference isn't even funny anymore: 10dB. Also the B&C plays much further towards the midrange. If mainly for music, I'd go with a B&C like driver. Even for movies It should still be heaps of fun.
I'd recommend running simulations of both drivers in comparable cabinets and seeing which compromise works for you.
I expect a pair of Ultimax 18"s would manage 120dB down to 20Hz, while a pair of B&C 18"s would manage 130dB above 40Hz. Both in ported boxes.
With today's bass-heavy music, the extra LF extension would be a lot of fun if you don't need the extra SPL you can get from high efficiency drivers with a higher cutoff.
Chris
I expect a pair of Ultimax 18"s would manage 120dB down to 20Hz, while a pair of B&C 18"s would manage 130dB above 40Hz. Both in ported boxes.
With today's bass-heavy music, the extra LF extension would be a lot of fun if you don't need the extra SPL you can get from high efficiency drivers with a higher cutoff.
Chris
Hey man, thanks a lot for your help.
I will definitely work with Hornsrep and figure these numbers out. Heres a question: so the B&C woofer reaches its Xmax limits @ 40Hz 115 dB which works out to about RMS 500 right, would the Ultimax or HO (Dayton Audio RSS460HO-4 18" Reference HO Subwoofer 4 ohm) give me the same performance at a higher RMS but simillar sized box?
Thanks for the post.
It seems there are no pro sub/woofer that can go as low as 20Hz while at the same time have great sensitivity. If you know of any that can would be great if you can share with me.
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