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Author Topic: Gona try this another way  (Read 1426 times)

Mike Spade

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Re: Gona try this another way
« Reply #10 on: May 15, 2018, 02:41:24 am »

Car stereo speakers load into the car and play in the near field.  Not a valid comparison.

The Yorkville driver is cast and has a different suspension, voice coil and cooling design. 

I find it hard to believe that driver takes full power for 36 hours but if you say so I am not going to dispute it.

You can only do so much with 20 dollars in manufacturing budget.  That is about all you have it a $60  driver.

Some basic ideas.  Front loaded cabinets have no gain and to get loud or low they need power and excursion.  Notice I said loud or low you can have one or the other with a front loaded cabinet, low efficiency drivers and relatively low power. 

Now horns can create acoustic gain.  It comes at a price however.  Designing horns is tricky business.   

Of you Google the terms in the speaker specs you can translate them to the WinISD equivalent.



Sent from my VS995 using Tapatalk

I did 36 hours TWICE last year, once this year and I'm gona do it again a 2nd time this year  ;D

If they die they die.

But I'm not expecting them to tbh, I know its hard to convince you of that without you being there in person tho.

"Some basic ideas.  Front loaded cabinets have no gain and to get loud or low they need power and excursion.  Notice I said loud or low you can have one or the other with a front loaded cabinet, low efficiency drivers and relatively low power. "

Well I guess it depends on what you think is low, I think 30hz is easily hitable.

But you make a good point about a front loaded reflex cab, they are not known for spl increase like a horn path or compression would. I'm open to other designs like a bandpass but I don't want to trade a few db or spl for higher distortion ratio or a delayed bass note, thats the main reason why the front loaded reflex cab is a lure to me, they sound good, its not always about being the loudest, this point is double as true when your talking about close range listening.

One of the reasons I mentioned bandpass was due to this suggesting its qts of 0.58 would make a good bandpass sub:

"Are you wanting to build a subwoofer? A high output mid bass cabinet? How about a full range PA box? There are specific low frequency drivers for each of these needs. A speaker that is best for a subwoofer box would be a poor choice for a mid bass application. A full range box will require a completely different speaker. Once you understand how to look at parameter values, you can use them to find the best component for your own particular need.

The first parameter to look at is the Qts.
This particular parameter will show which category the speaker will be best for. Remember these are guidelines, and there are always exceptions. Usually you can go a little either way with your Qts values for each of these categories.

.40 and above. As you go higher in value above .40, your speaker will only have flat response in very large vented boxes or sealed boxes. .40 to .50 will usually work well in a sealed, vented band pass box. That is an enclosure with a sealed rear chamber and a vented front chamber. Usually the .45 to .55 area is best for this type of box.

.37 to .40. This category works well for larger subwoofer boxes where the box can go as low as possible, and it won’t be used above 80 to 100 Hz. These woofers tend to lack punchy mid bass detail but still respond quick enough in the low bass region.

.30 to .36. This category would be the best choice for a high output subwoofer where the box can reproduce low frequencies without having to use a lot of equalization. This is a good region for the bass speaker of a full range box. Band pass enclosures with vented chambers on either side of the driver like Qts values in this area. Values in .35 area will perform well in larger boxes and values in the .27 to .30 area will be best for smaller band pass boxes with a slightly higher low frequency limit.

.26 to .29. This range is ideal where box size is critical and you still desire to get flat response to your tuning frequency. If you choose a woofer with a Qts of lower than .27, added equalization will be required to get flat response to your tuning frequency. This is a good area for small, full range boxes and small subs.

.22 to .26. Speakers in this area are ideal for dedicated mid bass speakers and small bass cabinets where added equalization is required. There is nothing wrong with this approach. The lower the Qts, the quicker the cone can move. With some careful equalization, you can end up with a stunning subwoofer in a smaller box size.

.21 and below. This range would work well for a horn loaded mid bass speaker. It would also be good for a mid bass component in a direct radiating full range box. You will have hard time getting low bass out of any speaker with a Qts below the .20 area.

Whatever the value, Qts should not be the only parameter to consider in your box design. An understanding of how Fs [free air resonance] and Vas [volume of air that matches the suspension springiness of the cone assembly] will be required. Understanding how these figures interrelate will help in determining speaker selection. Below is an optimum box design chart.

Qts of your speaker
Multiply your Fs
by this number to
get the frequency
to tune your box at
Divide this number
into the Vas to
get the size to make
your box
Multiply this number by
your Fs to tell the -3db
down pint of your box"
« Last Edit: May 15, 2018, 07:31:46 am by Mike Spade »
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Scott Holtzman

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Re: Gona try this another way
« Reply #11 on: May 15, 2018, 03:01:08 am »



I did 36 hours TWICE last year, once this year and I'm gona do it again a 2nd time this year  ;D

If they die they die.

But I'm not expecting them to tbh, I know its hard to convince you of that without you being there in person tho.

"Some basic ideas.  Front loaded cabinets have no gain and to get loud or low they need power and excursion.  Notice I said loud or low you can have one or the other with a front loaded cabinet, low efficiency drivers and relatively low power. "

Well I guess it depends on what you think is low, I think 30hz is easily hitable.

But you make a good point about a front loaded reflex cab, they are not known for spl increase like a horn path or compression would. I'm open to other designs like a bandpass but I don't want to trade a few db or spl for higher distortion ratio or a delayed bass note, thats the main reason why the front loaded reflex cab is a lure to me, they sound good, its not always about being the loudest, this point is double as true when your talking about close range listening.



Well my $2500 touring double 18's are like 9db down at 30hz.  These had the entire engineering team of JBL/Harman behind them. 

The drivers are cast and employ a high tech suspension.

This is why I am skeptical.  If such a box could be made would you not think that someone would have done it?

There are some high efficiency subs, they don't use 18" drivers.  It takes power to move the extra mass and accelerate all that air.





Sent from my VS995 using Tapatalk

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Mike Spade

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Re: Gona try this another way
« Reply #12 on: May 15, 2018, 03:07:46 am »


Well my $2500 touring double 18's are like 9db down at 30hz.  These had the entire engineering team of JBL/Harman behind them. 

The drivers are cast and employ a high tech suspension.

This is why I am skeptical.  If such a box could be made would you not think that someone would have done it?

There are some high efficiency subs, they don't use 18" drivers.  It takes power to move the extra mass and accelerate all that air.





Sent from my VS995 using Tapatalk

They HAVE done it. Behold the VBSS:
http://www.avsforum.com/forum/155-diy-speakers-subs/2226642-v-b-s-s-diy-subwoofer-design-thread.html

Its 17hz or 31hz depending on if you take out the middle section of the stock port tube.

Thats a $90 pa driver and a $300 amp, granted it only works due to the dsp in that amp.

So I mean its possible, you may not like it for what your doing, but its totaly possible to do with a cheap lower wattage driver.

Heres the settings used in the dsp so you can use it in other dsps aside of the inuke 3000 dsp.

VBSS-18 iNuke settings, EQ settings can also be used with other DSP's

Note settings should be the same for both channels, make sure you enter for both if you are using subs on both channels.
If using DSP other then Inuke convert DEQ settings to regular EQ settings and ignore the other variables.


-15Hz tuning
Configuration:

Bi-Amp1,
limiter=71.5Vp, hold=30ms, release=20ms

Filter/crossover:
Highpass 20hz Butterworth 12dB
Lowpass 250hz Butterworth 12dB

PEQ:
LowShelf12dB/oct 20hz +15dB (you can choose any unused filter for this, the rest can be used for room EQ)
 
DEQ:
Band 1
Gain 14dB, 20hz, Q=0.50, type BP, Threshold -27dB, attack 5ms, release 20ms, ratio 1:10
Band 2
Gain -10.5dB, 23hz, Q=0.90, type BP, Threshold -60dB, attack 5ms, release 20ms, ratio 1:10



-20Hz tuning
Configuration:

Bi-Amp1,
limiter=71.5Vp, hold=20ms, release=20ms

Filter/crossover:
Highpass 20hz Butterworth 12dB
Lowpass 250hz Butterworth 12dB

PEQ:
LS12 20hz +2dB (you can choose any unused filter for this, the rest can be used for room EQ)
 
DEQ:
Band 1
Gain 15dB, 20hz, Q=0.75, type BP, Threshold -33dB, attack 5ms, release 20ms, ratio 1:10
Band 2
Gain -1.5dB, 23hz, Q=3.00, type BP, Threshold -60dB, attack 5ms, release 20ms, ratio 1:2.0



-31Hz tuning
Configuration:

Bi-Amp1,
limiter=84Vp, hold=20ms, release=20ms

Filter/crossover:
Highpass 25hz Butterworth 18dB
Lowpass 300hz Butterworth 12dB
 
DEQ:
Band 1
Gain 6dB, 28hz, Q=1.00, type BP, Threshold -27dB, attack 5ms, release 20ms, ratio 1:10






~~~~~~~~~~~~~~~~~~~

I managed to get the driver into winisd, turns out the BL and QTS was slightly off in their specs, so after letting winisd auto, I was able to get the sub into winisd.

Looking at 4th order bandpass and vented reflex box atm and I'm not seeing bad results honestly, sure nothing thats gona keep up with 18sound drivers/cabs but totally usable down to 30hz.
« Last Edit: May 15, 2018, 07:35:18 am by Mike Spade »
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Ivan Beaver

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Re: Gona try this another way
« Reply #13 on: May 15, 2018, 07:55:23 am »


So the price is what makes it trash? So your saying the 500w 18 I have in the orginal yorkville sw1000 that would cost me $450 is better then the $60 driver purely cuz of the price? Despite both playing around the same volume in the same cases with the same wattage?
There is a lot more going on than "simple specs", and very often, on the cheap drivers, the specs are VERY misleading.

If you are interested in simply watts, then hook up a toaster to the amplifier-but very loud, but it does "handle a lot of watts".

Regarding freq response, EVERY SINGLE speaker ever made will EASILY reproduce 1Hz.  Simply apply 1 hz and watch it move in and out-even tweeters.

That does not mean that it is loud, but they DO go down to 1Hz.

What you are concerned with is ACTUAL USABLE performance.

That is often quite different than the numbers presented.

My car can easily get 100 miles per gallon.  If I let it coast down a long hill.

That does not represent real driving conditions, but I CAN get that milage, under the special conditions of the measurement.

That is why you have to be careful with the "numbers"
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Matthias McCready

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Re: Gona try this another way
« Reply #14 on: May 15, 2018, 08:20:23 am »

They HAVE done it. Behold the VBSS:
http://www.avsforum.com/forum/155-diy-speakers-subs/2226642-v-b-s-s-diy-subwoofer-design-thread.html

Its 17hz or 31hz depending on if you take out the middle section of the stock port tube.

Thats a $90 pa driver and a $300 amp, granted it only works due to the dsp in that amp.

So I mean its possible, you may not like it for what your doing, but its totaly possible to do with a cheap lower wattage driver.

I think you are confusing home audio and pro audio. With all due respect, they are not the same. I have an HSU Research subwoofer that can go down to 16hz (+/-2 db). It has a phenomenal low end, uses little wattage, and is as large as PA subwoofer, weighing in at 110Lb's. As it cost a $1,000 new, I can guarantee the driver is probably less than $100.

While it sounds good, goes low, and is great for home use, it is still NOT a Pro Audio Sub and to use it in such a manner would ruin it. It is not meant to cover bass for a large area, and it is not meant to be pushed as hard or for as long. A PA sub at an equivalent cost, might offer the same size driver and it would probably be lighter, it would not sound as good (not as detailed, accurate, punchy), but it would be up to the task. Pro Sound sacrifices quality for quantity, especially at the low end of the market, which is squarely where you sit (even with your capability to potentially build something above your normal budget).

Are there subs that can perform this stuff live? Yes, Meyer Sound, for example, makes a new element that is intended to reproduce 30-13hz, that costs upwards of 5 figures per sub and I can guarantee you cannot recreate it even if you spent decades trying to, like other brands, they have experts researching for decades. This comes down to a lot more than carpentry skill.

Mike, I am not trying to be mean, but you keep equating subs between car, home, and Pro Sound. These are not the same thing. Yes, they may have the same driver sizes. However, pro audio is very different from either of these.

If there is going to be a logical discussion going forward, where forum members can help you, you need to stop equating and making generalizing statements.

For example: Just because you like a cheaper driver in one instance does not mean that all expensive drivers are a waste of money.

Often when people offer you a scientific fact or a piece of advice which based solidly in physics, which behaves no differently in Canada, you take that as subjective opinion stating "that does not work for me."

Bottom line: Let's keep the science objective, not relative.  :)

EDIT: The entire point of experimentation and established science is that the steps are repeatable and that the results will be the same. If the results are not the same, then the means of the experiment have changed.
« Last Edit: May 15, 2018, 08:35:08 am by Matthias McCready »
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Lee Buckalew

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Re: Gona try this another way
« Reply #15 on: May 15, 2018, 08:21:06 am »

They HAVE done it. Behold the VBSS:
http://www.avsforum.com/forum/155-diy-speakers-subs/2226642-v-b-s-s-diy-subwoofer-design-thread.html

Its 17hz or 31hz depending on if you take out the middle section of the stock port tube.

Thats a $90 pa driver and a $300 amp, granted it only works due to the dsp in that amp.

So I mean its possible, you may not like it for what your doing, but its totaly possible to do with a cheap lower wattage driver.

What Scott mentioned was you can't have both low and loud without increasing cost. 
The driver and cabinet combo that you have shown proves his point.  It can be tuned for low frequency output but, EQ'd flat it will have a peak SPL around 114 dB with a continuous SPL capability of around 108dB.  When you then consider that a typical tuning for rock, pop, etc. requires the sub frequencies to have a 15 dB haystack and some styles may even desire more than that you now have a sub that limits your system output to around 93dB/SPL, at 1 meter long term. That would be indoors.  Outdoors you would need even more subwoofer output to reach the same level.  Typically it is good practice to consider 2-4 times the number of subs for outdoors that you could use indoors.

So, how loud do you need to be at the listeners?
How far away are they from the speakers?

Lee
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Matthias McCready

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Re: Gona try this another way
« Reply #16 on: May 15, 2018, 08:27:08 am »

So, how loud do you need to be at the listeners?
How far away are they from the speakers?

Lee

This.
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David Allred

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Re: Gona try this another way
« Reply #17 on: May 15, 2018, 08:57:33 am »

"It's like deja vu all over again." - Yogi Berra
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Nathan Riddle

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Re: Gona try this another way
« Reply #18 on: May 15, 2018, 09:26:37 am »

In fear for my/our sanity I say this carefully.

I don't make money renting my equipment. This is a hobby gone wildly out of control to the point where I now have land and do monthly events on said land. So I mean cost matters to me.

I wish you had said this at the start.

Okay since everybody seems so concerned about my sound system and can't stay on subject, lets try this another way.

I have zero gear.
I have a limited budget so buying new higher powered subs or amps isn't a option.
I have limits on power draw so buying a new high wattage amp and 18s isn't a option even if I had the budget. I have been donated a 500w rms amp and two 600w rvp 18s.
I have unlimited storage so cab size doesn't matter, it doesn't need to be small or compact.
I want it to 30hz.
All designs are on the table, bandpass, orders, reflex ect.
I have unlimited wood and case building supplies.

These $60 ones where supposed to be "temp" drivers till I saved up for the $450 ones.

What kind of case would you make for these for sub bass above 30hz?
https://www.rockvilleaudio.com/rvp18w8/

My take? Build 3 boxes for 'fun' to test out and see how you like them.

Using your two drivers & amps:

Build the G Sub.
Build a Keystone sub.
Build a model in WinISD of your own design (whatever models well, try out 5 different types of subs in software for free (just time), and then build the one that looks awesome).

Then test out each, record a video, if you had a measurement mic post TF traces and report back here. I'm sure the community here would love to see your thoughts on all three and see the traces.

I'm definitely curious.

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Art Welter

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Re: Gona try this another way
« Reply #19 on: May 15, 2018, 01:07:02 pm »


1)Lets pretend I have limits on power draw so buying a new high wattage amp and 18s isn't a option even if I had the budget.
2)Lets pretend I have been donated a 500w rms amp and two 600w rvp 18s.
3)Lets pretend I have unlimited storage so cab size doesn't matter, it doesn't need to be small or compact.
4)Lets pretend I wanted it to go as low as 30hz.
5)Lets pretend all designs are on the table, bandpass, orders, reflex ect.
6)Lets pretend you got unlimited wood and case building supplies.
7)What kind of case would you make for these for sub bass above 30hz?
https://www.rockvilleaudio.com/rvp18w8/
8)Would you use a bass reflex design like yorkvilles sw1000 or communitys s218 or "the gsub"? If not, why not?
9)Would you use a different or more compact design like a sb1000? If not, why?
10)Do you know of any already made dual 18 cases made by any manufacturer that is around the same wattage of 1000-1200w rms with good results?
1)A class D amp could draw less than 50% of the power of an older design, for instance a Behringer NU4-6000 can put out over 3600 watts drawing 31 amps, while a Crest CA9 drew 37.8 amps while putting out only 1600 watts.
2)Ok, we work with what we got.
3) Bigger is better for bass.
4) A lot more bigger for a few lower Hz..
5) Take off all but horns if you want loud and low with just two cheap 18". If you use multiple bass-reflex cabinets and drivers wired in series-parallel, you can achieve similar efficiency, but violates premise #2.
6) OK, good- you'll need them.
7) I'd design a huge dual 18" FLH horn in Hornresp with an FC of 30 Hz, and surround it with wings/barn doors (sheets of plywood) to increase forward gain. The horn would be so large it would be built in at least two parts.
8)No, see #5.
9) No, see #5.
10) No, most designs are made to either be small and cheap, or small and louder with more cost.

Cheers,
Art

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