Alright, I'm not too familiar with cheap subwoofers. My friend would like a small sub like an 8" or a 10" to fill in some lows in his 2008 Saturn Astra 3 Door.
What type of subwoofer would you recommend to get clean bass on the cheap (8" or 10")? I'm talking about a raw speaker because we're going to build a custom cabinet in the hatch for it.
Replies (23)
Ash on 12/20/2008 06:39:21
Looking at this type of compact car I would go with a compact sub. A single 8 with about 150 rms watts will do just fine in a small hatch if all other speakers are running stock. For extra output & depending on music tastes, a ported enclosure will suffice and not tax your electricals much. There are quite a bit of amps in that power range with a subsonic filter to make the package easily completed.
My favorite for this type of setup is Dayton with it's 5 year warranty:
http://www.parts-express.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-545&ctab=9#Tabs
With about a .6 ft^3 box and 2" x 11" port the sub blends nicely with small interior cars as the F3hz is around the 40-50 hz mark but will extend lower with the car's transfer function. This makes for very clean bass. I built one for a friend's blazer and was surprised how good it sounded on various music genres.
As far as an amp goes, in the low power range 150-200 rms class D is not entirely important. A solid A/B amp with mosfet outputs will do fine. The mosfet outputs are key to A/B amps' efficiency. Class D is more efficient & smaller overall so you can take your pick with either. Also, if you opt for ported, then make sure you choose an amp with an appropriate subsonic filter. If you go sealed, then pretty much any good quality amp will do..
The main thing to consider is what is going to feed the amp: aftermarket or stock receiver? If the amp does not have high level (speaker) inputs then you may have to incorporate a LOC to utilize a stock HU.
This Alpine fits these options nicely and makes subwoofer upgrades easier. Plus it is a favorite here:
http://www.sonicelectronix.com/item_6470_Alpine+MRP-M450.html
ttocs on 12/20/2008 10:33:45
$?
hooviemoto87 on 01/2/2009 14:58:08
He is hoping for $250 ish
hooviemoto87 on 01/2/2009 15:04:36
thanks for the input. I was wondering if an 8" would be enough. I imagined it would because in a hatchback you get the bass bouncing off the glass. I had to go up to a 10" in my cobalt since it's in the trunk. After talking to him more, it looks like we will build a sealed box. He wants to be able to listen to classical on it. He listens to rock, classical, a little rap, and country.
So, if we install something that is around 150 watts, that will be sufficient for him?
ttocs on 01/2/2009 22:09:57
an 8 with some power on it will fill in his low end that he is lacking. If he is wanting to go blasting rap music so the neighbors can hear it then he will need to aiim a little higher. If he can find a 10 in his budget then go for it.
swez on 01/3/2009 14:23:44
Looks like Ashs' combo is a definite winner. The amp is very good and stable @ 2 ohm loads.
A pair of Dayton 8's in a well matched sealed enclosure would be compact and still pump out some solid bass for the budget amount in mind. When all the parts are purchased and assemled, his budget will be a bit higher, but worth the extra expense.
This sub can be used in a very compact sealed box or ported. Here are the recommeded specs per sub:
http://www.parts-express.com/pdf/295-545%20sealed.pdf
http://www.parts-express.com/pdf/295-545%20vented.pdf
The low end bass performance curve looks much better in the ported design. It goes lower and more SPL output below 50 Hz., when compared to sealed. When considering "Cabin Gain" affects in this hatchback, figure a solid 125 dB of SPL with a pair of these subs.
Not too shabby for such a low budget system,
Swez
Ash on 01/4/2009 17:05:40
The broad range of genres that he listens to will suggest a compromise for there is no perfect setup that plays everything well. Rap and classical are on opposite ends of the musical spectrum. Rock and country benefit from having some meat around the bass guitar range although rock needs good snap for drums.
Two of those subs in the recommended sealed will sound good in a compact car as the small cabin will render much deeper bass. With the subs being in a low Qtc box, transient response will be smooth. Doesn't look good on paper, but in the car will prove other wise. Those subs align with the old round Kicker solobaric's nature opposite of what is made today.
swez on 01/4/2009 19:19:49
You make a good point there Ash!
Cabin gain is something we know is a key factor, but few have the tools to determine the net results of where the gain factor proved most beneficial. Based on your own experiments, can you give the general "guy on the street" and overview of what he/we can expect in the general gain factors noted below? Let's confine the parameters to gain and frequency response predictions. (Keep it general for now OK?)
Yes, the playground is large and there are many common vehicle makers in this game, but is it possible to predict gain curves and approximate resonance points for:
A. Large format SUV's
B. Medium format SUV's and PU truck
C. Typical full-sized sedans
D. Compact SUV's, sedans and hatchbacks
Yes, there are many other variables to consider here, but if we look at the Fb of the cabin space outside the woofer enclosure.
Have to break loose for now, but will come back later for your comments OK?
Swez
Ash on 01/5/2009 06:07:05
Yes Swez, it is possible to predict somewhat what a design will do in a particular environment. That is once we understand that environment. As an quick example:
You remember some time back when I was playing around with a pair of Credence 8's? Low Q sealed with a high roll off around 75hz if I remember.... Well at that time I first had it in a 1992 Nissan 240sx hatchback. The frequency response was incredible for two 8's. Very smooth, deep extension, and easy to blend with a 5.25 comp set in the doors.
Well, remember later on when I tried them in my 4 door S10 Blazer? Same amp, deck, and components, but the response was just horrible compared to before. Boomy with no depth, although transient response was still ok, (low Q box still). What happened?!!
Small cars (especially hatch's) normally have high lifts (say 12db) that starts higher say upper 50's - 60hz. When matched with a early rolloff sub, this presents a smooth response as the car picks up where the sub leaves off.
Larger suv's (in this case) have less lift (say 5db) but at a lower frequency say 30-40hz. Now with that same box there is a major gap from 40-70hz or the lack there of below the sub's rolloff. The two just don't mate up. Needless to say I got rid of the 8's for a larger sub that easily dipped well below 50 hz and low end bass returned.
Hope my example explains enough..... If not, hopefully Swez or somebody will step in and clarify things a bit,,,, I'm in a rush to head to work. LOL
Victor on 01/5/2009 06:58:13
I get what you are trying to say there 'Ash ....
Unfortunately such a prediction can only be done after trying several woofers with several enclosures in several orientations in one single car to collect data for that particular vehicle, meaning several other vehicles with varied acoustic properties....
this would become a huge R& D database to serve a prediction software ... and even then it will just be a prediction .....
there can be no mathematical generalization of this.
( if it was a room of a particular fixed dimension that is inert to sound only then can all the parameters be compared on a similar platform )
so the best way to do this is what the manufacturers do ... collect mechanical and electrical data of the free air response .... which are the Thiele Small Parameters ...
http://sound.westhost.com/tsp.htm
Since it was not possible to measure the exact characteristics and response of a driver as the acoustic environment would affect it in some way, hence Thiele and Small devised a method to put all drivers on the same platform of free air and measure its responses ......
Note these in the link above ..
""""The need for accuracy cannot be stressed too highly if accurate parameters are expected. It should also be understood that there are many variables and many opportunities for things to go awry - during measurement, construction and normal operation. Loudspeakers are variable beasties at best, and 'perfect' results will never be obtained in practice. The room will usually cause more and greater errors than a small measurement error here.""""
&
"""The loudspeaker driver should be suspended in free space, with no obstructions or interfering surfaces nearby. Any boundary closer than around 600mm (about 2ft) will affect the accuracy of the measurements"""
Victor...
PS: & Every response prediction software, enclosure design software etc ... ( whatever software it is, works on the basis of these TS parameters - which again is never equal to the response measured under real time application )
Ash on 01/5/2009 16:19:43
Actually Victor, it is predictable to a certain extent. Using a simple process to map out the particular cabin gain of the vehicle at hand, one can get fairly close to a desired response.
Taking a enclosed test driver, calibrated mic, RTA, test tones, and required gear to drive the signals you can record the speaker's response in an open field measurement. Once you have the response recorded you take that same speaker, place it in the car, and run the same test tones (pink noise preferred). Once you have recorded that response you can see the peaks or dips the car's acoustics have made and can start to create a subwoofer design to naturally tailor the response to what you like.
This is a very basic process, although many shops do not utilize this. Instead they build hit or miss and depend heavily upon manufacturer recommendations. Using that type of testing will allow an installer to even know what subs will or will not work and what changes can be made to get the desired result. I wonder how many installs got bashed from the lack of knowledge on how to map it out right???
Not for your everyday boomer, but for SQ this is almost a must if you want it right with less effort.
Ash,
Victor on 01/5/2009 22:08:34
I do not disagree...
isolated case where it is done keeping just one acoustic environment and just 1 or 2 subs and enclosures is a different thing,
where as an ability to predict with minimum error on a wider base cannot be a concrete system until a whole lot of data is collected, segregated and analyzed ...
1 - sooo many drivers available in the market
2 - sooo many different cars in the market
3 - sooo many different sizes and types of enclosure...
how many permutations & combinations would one have to go through to gather an in-depth database for a system that predicts with minimum error.
Also
Above you stated
"Taking a enclosed test driver, calibrated mic, RTA, test tones, and required gear to drive the signals you can record the speaker's response in an open field measurement."
well.. this is a general practice.... most manufacturers provide this data and response graphs.
TS parameters - Sealed / Ported enclosure in open space ( Anechoic Room ) - Sealed / Ported in Car response ( God knows what car each of them use )
All these are real time responses and measurements . by actually playing the driver under various conditions in various states...
"" Where as we are talking about predicting a response ( without any real time measurements ), or a response simulator that would precisely simulate the response of a particular driver in a particular enclosure put in a particular acoustic environment..
this I say would not be possible as "when acoustic properties of a surroundings are to be factored, there is no thumb rule or mathematic calculation that can be applied to the behavior of different acoustic environments..""
With experience we sure can say what car sounds sweet, which one would eat up bass, which one would give us a spike within a particular freq range ... this is purely experience ( even if its recorded as data ).
Victor...
Ash on 01/6/2009 16:24:27
I think you are missing the point here Vic.... Quoted from Swez "if we look at the Fb of the cabin space outside the woofer enclosure". Of course to know this would mean to test that particular vehicle regardless if your last install was in the same type.
Another question Swez asked "is it possible to predict gain curves and approximate resonance points". Again my answer is yes through testing and it does not have to have a large database of speakers to find the vehicle's corner frequency, peaks, dips. All you need is the definite open field response of a single test speaker and see what changes that same particular car makes. I also suggest using a speaker that you have open field tested yourself.
As far as the manufacturer's plot is concerned, unless they have thorough info with plots and how those plots were attained, then it's somewhat useless. If you ever tested a speaker to extract it's parameters, you will find some can be right on spot, off a bit, or even straight out lying.
I agree about the experience, but I'm a firm believer in gathering data as well. With me it goes hand in hand. However the amount of people that are willing to go that are few in the car audio realm. This can account for people only relying on certain brands or certain setups. This is also how Bose is able to produce merchandise using inferior drivers, through manipulation of acoustics..... Maybe not a good example, but I think you get the picture.
Have you ever read any of Vance Dickason's books?
swez on 01/6/2009 18:55:33
I have to agree with Ash here as this is exactly how Action Audio "fine tunes" a known set of drivers to the environment of a given room &/or sound stage.
We know the general parameters of the speakers/drivers we plan to use. We plot the best placement for such drivers and them run a "Pink Noise" signal to profile a given system to the environment we are dealing with and do time alignments as well. Yes, this takes time and experience. But the more we know and trust compesation tools, the quicker the "window" of adjustments comes on sceen.
After the time alignments are established and we spot the peaks and dips in a given listening field, we can now employ active DSP tools to flatten out the system as best as possible and adjust "on-the-fly". (That tool is a multi-band, parametric EQ w/ varialble Q and selectable digital EQ bandwidth points.
Dale's very good at this as he's been at this for over 10 years. I have observed some of his magic, but my part in the game is more often the guy in the audio field, with the calibrated mike to read each zone. (Not the RTA tweaker)
Since zones vary acoustially for many reasons, (Reflections, overlaps, cancellations, time delay and absorbing characteristics, it's a mixed bag, all night long.
In the end, it boils down to good tools to get us in the ballpark. From there, it's a well-trained set of ears to blend it all together and adjust on-the fly as well.
Swez
Victor on 01/7/2009 04:59:43
"this is exactly how Action Audio "fine tunes" a known set of drivers to the environment of a given room &/or sound stage."
and all that swez wrote... and all that ash wrote.. i still agree with you guys.. This is how I tune systems too...
guess we are talking about different things..
When talked about prediction ...
This is what came to my mind
A client comes to me, says he has ABC car, and he wants a XYZ Bass package , but he would like to know how 5 different combos would sound ... now it wont be possible for me to show him every combo he expects to audition.
So if I had a database, I could simulate ( predict ) a response graph on the laptop( using different drivers/enclosures/cars ) and show him the difference in performance, which would help him select easily and also make it hassle free for me...
Victor...
Ash on 01/7/2009 05:46:29
Lol!!! We are all on the same page here just different language. Okay, but did we help with hooviemoto's ride? Essentially we are all talking from experience, but we are wise enough to put our heads together to answer this simple question as well.
From experience, what kind of plot do we think his small hatch will have and what sub package do we recommend to mate up with his stock stereo with his musical tastes?
Victor on 01/7/2009 06:16:01
The plot seems pretty simple here..
a decent 10" sub in a sealed enclosure powered anywhere between 150-300wrms..
( 10" and upto 300wrms, so that bass package would not stand out of place and try to keep up with the varied range of music he listens to )
for example..
http://www.crutchfield.com/p_107MM1040D/Polk-Audio-MM1040D.html?showAll=N&tp=111
+
http://www.crutchfield.com/p_023THA125P/Blaupunkt-THA1250PnP.html?tp=115
( by the way, this blau amp is a very good example of an old saying ""Good Things Come in Small Packages"" )
Victor...
PS: You could pick up sub + amp combo from any reputed manufacturer. just see that the sub is a 10" capable of performing in a small sealed enclosure and can take around 300wrms power, paired with a simple but performing monoblock ....
swez on 01/7/2009 06:56:23
This is just way to much fun to observe, but for the sake of others, we can stop now. I see the same patterns of responses that all point in one general direction...
"Fit the speakers to the acoustical environment that we are working in". That's always easier said than done. Audio Engineers are now part of the early design team for premium sound systems in upscale cars. (It's about time as this was just an after-thought a few years back)
The tough part here, they optimize the system around general parameters that do not suit all music genres well, but do a good job in a narrow scope of music/audio the target buyer will use most. I'll say this... it ain't Rap and not just Talk Radio, Jazz, Classical, Soft Rock or NPR, but something that does the latter 5 well. Rap suffers in the end. (Not the targeted audience for Audi, Jaguar, BMW, Caddy, Lincoln and other)
If you drive one of these and love Rap or Hip Hop, plan on ripping out the whole system and start from scratch !
Swez COFFEE
Ash on 01/10/2009 06:24:29
You're on spot here Swez. This debate is to no avail. The aspect that needs attention is the different genres that will be listened to. In this case I would suggest any woofer capable of F3's in the 50-70hz range but in a low Qtc sealed box (.707).
Small subs (8-10") mate better in small hatch cars and low to medium power (150-200 rms) if all else is powered by the HU. This is pretty straightforward, but don't expect perfection with all music. A built-in EQ in the HU will help with the genres styles.
swez on 01/10/2009 09:31:24
LOL
Three bright people in room, analyzing a simple concept to the Nth degree, all coming at the plan from various angles and arriving at the same conclusion. Amazing feat all by itself huh?
Vic's database idea makes a lot of sense for high end customers. Ash's methodology would help you get there. By removing as many minor variables as possible, one could profile a vehicle in short order with much practice.
It's been fun guys,
Dave
Victor on 01/10/2009 09:47:32
3 bright people .... !
Whose the 3rd one ??? GRIN
swez on 01/10/2009 10:11:33
The quiet guy in the corner that's reading all this jibber-jabber and says nothing. He is the wise one!
Well, we got some fresh snow last night and it's high time to get out there and deal with it. Whoopie! (-5 C; winds NE 20kph; 3-5" of new snow at 10:00 am; 1/10/2009)
Swez
Ash on 01/10/2009 20:45:52
Whoopie?!!! Between the minor cold snaps, luke warm weather breaks, and lying weathermen our spotted sea trout fishing season is pretty much over. We had some major cold weather come in early about 1.5 months ago that had everyone thinking this was going to be a good winter for trout and now it's ruined. It ends the 1st of Feburary and there's no way the water will get cold enough before then for it to be worth it. The pawn shops are full of fishing gear!
What type of subwoofer would you recommend to get clean bass on the cheap (8" or 10")? I'm talking about a raw speaker because we're going to build a custom cabinet in the hatch for it.
Replies (23)
Ash on 12/20/2008 06:39:21
Looking at this type of compact car I would go with a compact sub. A single 8 with about 150 rms watts will do just fine in a small hatch if all other speakers are running stock. For extra output & depending on music tastes, a ported enclosure will suffice and not tax your electricals much. There are quite a bit of amps in that power range with a subsonic filter to make the package easily completed.
My favorite for this type of setup is Dayton with it's 5 year warranty:
http://www.parts-express.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-545&ctab=9#Tabs
With about a .6 ft^3 box and 2" x 11" port the sub blends nicely with small interior cars as the F3hz is around the 40-50 hz mark but will extend lower with the car's transfer function. This makes for very clean bass. I built one for a friend's blazer and was surprised how good it sounded on various music genres.
As far as an amp goes, in the low power range 150-200 rms class D is not entirely important. A solid A/B amp with mosfet outputs will do fine. The mosfet outputs are key to A/B amps' efficiency. Class D is more efficient & smaller overall so you can take your pick with either. Also, if you opt for ported, then make sure you choose an amp with an appropriate subsonic filter. If you go sealed, then pretty much any good quality amp will do..
The main thing to consider is what is going to feed the amp: aftermarket or stock receiver? If the amp does not have high level (speaker) inputs then you may have to incorporate a LOC to utilize a stock HU.
This Alpine fits these options nicely and makes subwoofer upgrades easier. Plus it is a favorite here:
http://www.sonicelectronix.com/item_6470_Alpine+MRP-M450.html
ttocs on 12/20/2008 10:33:45
$?
hooviemoto87 on 01/2/2009 14:58:08
He is hoping for $250 ish
hooviemoto87 on 01/2/2009 15:04:36
thanks for the input. I was wondering if an 8" would be enough. I imagined it would because in a hatchback you get the bass bouncing off the glass. I had to go up to a 10" in my cobalt since it's in the trunk. After talking to him more, it looks like we will build a sealed box. He wants to be able to listen to classical on it. He listens to rock, classical, a little rap, and country.
So, if we install something that is around 150 watts, that will be sufficient for him?
ttocs on 01/2/2009 22:09:57
an 8 with some power on it will fill in his low end that he is lacking. If he is wanting to go blasting rap music so the neighbors can hear it then he will need to aiim a little higher. If he can find a 10 in his budget then go for it.
swez on 01/3/2009 14:23:44
Looks like Ashs' combo is a definite winner. The amp is very good and stable @ 2 ohm loads.
A pair of Dayton 8's in a well matched sealed enclosure would be compact and still pump out some solid bass for the budget amount in mind. When all the parts are purchased and assemled, his budget will be a bit higher, but worth the extra expense.
This sub can be used in a very compact sealed box or ported. Here are the recommeded specs per sub:
http://www.parts-express.com/pdf/295-545%20sealed.pdf
http://www.parts-express.com/pdf/295-545%20vented.pdf
The low end bass performance curve looks much better in the ported design. It goes lower and more SPL output below 50 Hz., when compared to sealed. When considering "Cabin Gain" affects in this hatchback, figure a solid 125 dB of SPL with a pair of these subs.
Not too shabby for such a low budget system,
Swez
Ash on 01/4/2009 17:05:40
The broad range of genres that he listens to will suggest a compromise for there is no perfect setup that plays everything well. Rap and classical are on opposite ends of the musical spectrum. Rock and country benefit from having some meat around the bass guitar range although rock needs good snap for drums.
Two of those subs in the recommended sealed will sound good in a compact car as the small cabin will render much deeper bass. With the subs being in a low Qtc box, transient response will be smooth. Doesn't look good on paper, but in the car will prove other wise. Those subs align with the old round Kicker solobaric's nature opposite of what is made today.
swez on 01/4/2009 19:19:49
You make a good point there Ash!
Cabin gain is something we know is a key factor, but few have the tools to determine the net results of where the gain factor proved most beneficial. Based on your own experiments, can you give the general "guy on the street" and overview of what he/we can expect in the general gain factors noted below? Let's confine the parameters to gain and frequency response predictions. (Keep it general for now OK?)
Yes, the playground is large and there are many common vehicle makers in this game, but is it possible to predict gain curves and approximate resonance points for:
A. Large format SUV's
B. Medium format SUV's and PU truck
C. Typical full-sized sedans
D. Compact SUV's, sedans and hatchbacks
Yes, there are many other variables to consider here, but if we look at the Fb of the cabin space outside the woofer enclosure.
Have to break loose for now, but will come back later for your comments OK?
Swez
Ash on 01/5/2009 06:07:05
Yes Swez, it is possible to predict somewhat what a design will do in a particular environment. That is once we understand that environment. As an quick example:
You remember some time back when I was playing around with a pair of Credence 8's? Low Q sealed with a high roll off around 75hz if I remember.... Well at that time I first had it in a 1992 Nissan 240sx hatchback. The frequency response was incredible for two 8's. Very smooth, deep extension, and easy to blend with a 5.25 comp set in the doors.
Well, remember later on when I tried them in my 4 door S10 Blazer? Same amp, deck, and components, but the response was just horrible compared to before. Boomy with no depth, although transient response was still ok, (low Q box still). What happened?!!
Small cars (especially hatch's) normally have high lifts (say 12db) that starts higher say upper 50's - 60hz. When matched with a early rolloff sub, this presents a smooth response as the car picks up where the sub leaves off.
Larger suv's (in this case) have less lift (say 5db) but at a lower frequency say 30-40hz. Now with that same box there is a major gap from 40-70hz or the lack there of below the sub's rolloff. The two just don't mate up. Needless to say I got rid of the 8's for a larger sub that easily dipped well below 50 hz and low end bass returned.
Hope my example explains enough..... If not, hopefully Swez or somebody will step in and clarify things a bit,,,, I'm in a rush to head to work. LOL
Victor on 01/5/2009 06:58:13
I get what you are trying to say there 'Ash ....
Unfortunately such a prediction can only be done after trying several woofers with several enclosures in several orientations in one single car to collect data for that particular vehicle, meaning several other vehicles with varied acoustic properties....
this would become a huge R& D database to serve a prediction software ... and even then it will just be a prediction .....
there can be no mathematical generalization of this.
( if it was a room of a particular fixed dimension that is inert to sound only then can all the parameters be compared on a similar platform )
so the best way to do this is what the manufacturers do ... collect mechanical and electrical data of the free air response .... which are the Thiele Small Parameters ...
http://sound.westhost.com/tsp.htm
Since it was not possible to measure the exact characteristics and response of a driver as the acoustic environment would affect it in some way, hence Thiele and Small devised a method to put all drivers on the same platform of free air and measure its responses ......
Note these in the link above ..
""""The need for accuracy cannot be stressed too highly if accurate parameters are expected. It should also be understood that there are many variables and many opportunities for things to go awry - during measurement, construction and normal operation. Loudspeakers are variable beasties at best, and 'perfect' results will never be obtained in practice. The room will usually cause more and greater errors than a small measurement error here.""""
&
"""The loudspeaker driver should be suspended in free space, with no obstructions or interfering surfaces nearby. Any boundary closer than around 600mm (about 2ft) will affect the accuracy of the measurements"""
Victor...
PS: & Every response prediction software, enclosure design software etc ... ( whatever software it is, works on the basis of these TS parameters - which again is never equal to the response measured under real time application )
Ash on 01/5/2009 16:19:43
Actually Victor, it is predictable to a certain extent. Using a simple process to map out the particular cabin gain of the vehicle at hand, one can get fairly close to a desired response.
Taking a enclosed test driver, calibrated mic, RTA, test tones, and required gear to drive the signals you can record the speaker's response in an open field measurement. Once you have the response recorded you take that same speaker, place it in the car, and run the same test tones (pink noise preferred). Once you have recorded that response you can see the peaks or dips the car's acoustics have made and can start to create a subwoofer design to naturally tailor the response to what you like.
This is a very basic process, although many shops do not utilize this. Instead they build hit or miss and depend heavily upon manufacturer recommendations. Using that type of testing will allow an installer to even know what subs will or will not work and what changes can be made to get the desired result. I wonder how many installs got bashed from the lack of knowledge on how to map it out right???
Not for your everyday boomer, but for SQ this is almost a must if you want it right with less effort.
Ash,
Victor on 01/5/2009 22:08:34
I do not disagree...
isolated case where it is done keeping just one acoustic environment and just 1 or 2 subs and enclosures is a different thing,
where as an ability to predict with minimum error on a wider base cannot be a concrete system until a whole lot of data is collected, segregated and analyzed ...
1 - sooo many drivers available in the market
2 - sooo many different cars in the market
3 - sooo many different sizes and types of enclosure...
how many permutations & combinations would one have to go through to gather an in-depth database for a system that predicts with minimum error.
Also
Above you stated
"Taking a enclosed test driver, calibrated mic, RTA, test tones, and required gear to drive the signals you can record the speaker's response in an open field measurement."
well.. this is a general practice.... most manufacturers provide this data and response graphs.
TS parameters - Sealed / Ported enclosure in open space ( Anechoic Room ) - Sealed / Ported in Car response ( God knows what car each of them use )
All these are real time responses and measurements . by actually playing the driver under various conditions in various states...
"" Where as we are talking about predicting a response ( without any real time measurements ), or a response simulator that would precisely simulate the response of a particular driver in a particular enclosure put in a particular acoustic environment..
this I say would not be possible as "when acoustic properties of a surroundings are to be factored, there is no thumb rule or mathematic calculation that can be applied to the behavior of different acoustic environments..""
With experience we sure can say what car sounds sweet, which one would eat up bass, which one would give us a spike within a particular freq range ... this is purely experience ( even if its recorded as data ).
Victor...
Ash on 01/6/2009 16:24:27
I think you are missing the point here Vic.... Quoted from Swez "if we look at the Fb of the cabin space outside the woofer enclosure". Of course to know this would mean to test that particular vehicle regardless if your last install was in the same type.
Another question Swez asked "is it possible to predict gain curves and approximate resonance points". Again my answer is yes through testing and it does not have to have a large database of speakers to find the vehicle's corner frequency, peaks, dips. All you need is the definite open field response of a single test speaker and see what changes that same particular car makes. I also suggest using a speaker that you have open field tested yourself.
As far as the manufacturer's plot is concerned, unless they have thorough info with plots and how those plots were attained, then it's somewhat useless. If you ever tested a speaker to extract it's parameters, you will find some can be right on spot, off a bit, or even straight out lying.
I agree about the experience, but I'm a firm believer in gathering data as well. With me it goes hand in hand. However the amount of people that are willing to go that are few in the car audio realm. This can account for people only relying on certain brands or certain setups. This is also how Bose is able to produce merchandise using inferior drivers, through manipulation of acoustics..... Maybe not a good example, but I think you get the picture.
Have you ever read any of Vance Dickason's books?
swez on 01/6/2009 18:55:33
I have to agree with Ash here as this is exactly how Action Audio "fine tunes" a known set of drivers to the environment of a given room &/or sound stage.
We know the general parameters of the speakers/drivers we plan to use. We plot the best placement for such drivers and them run a "Pink Noise" signal to profile a given system to the environment we are dealing with and do time alignments as well. Yes, this takes time and experience. But the more we know and trust compesation tools, the quicker the "window" of adjustments comes on sceen.
After the time alignments are established and we spot the peaks and dips in a given listening field, we can now employ active DSP tools to flatten out the system as best as possible and adjust "on-the-fly". (That tool is a multi-band, parametric EQ w/ varialble Q and selectable digital EQ bandwidth points.
Dale's very good at this as he's been at this for over 10 years. I have observed some of his magic, but my part in the game is more often the guy in the audio field, with the calibrated mike to read each zone. (Not the RTA tweaker)
Since zones vary acoustially for many reasons, (Reflections, overlaps, cancellations, time delay and absorbing characteristics, it's a mixed bag, all night long.
In the end, it boils down to good tools to get us in the ballpark. From there, it's a well-trained set of ears to blend it all together and adjust on-the fly as well.
Swez
Victor on 01/7/2009 04:59:43
"this is exactly how Action Audio "fine tunes" a known set of drivers to the environment of a given room &/or sound stage."
and all that swez wrote... and all that ash wrote.. i still agree with you guys.. This is how I tune systems too...
guess we are talking about different things..
When talked about prediction ...
This is what came to my mind
A client comes to me, says he has ABC car, and he wants a XYZ Bass package , but he would like to know how 5 different combos would sound ... now it wont be possible for me to show him every combo he expects to audition.
So if I had a database, I could simulate ( predict ) a response graph on the laptop( using different drivers/enclosures/cars ) and show him the difference in performance, which would help him select easily and also make it hassle free for me...
Victor...
Ash on 01/7/2009 05:46:29
Lol!!! We are all on the same page here just different language. Okay, but did we help with hooviemoto's ride? Essentially we are all talking from experience, but we are wise enough to put our heads together to answer this simple question as well.
From experience, what kind of plot do we think his small hatch will have and what sub package do we recommend to mate up with his stock stereo with his musical tastes?
Victor on 01/7/2009 06:16:01
The plot seems pretty simple here..
a decent 10" sub in a sealed enclosure powered anywhere between 150-300wrms..
( 10" and upto 300wrms, so that bass package would not stand out of place and try to keep up with the varied range of music he listens to )
for example..
http://www.crutchfield.com/p_107MM1040D/Polk-Audio-MM1040D.html?showAll=N&tp=111
+
http://www.crutchfield.com/p_023THA125P/Blaupunkt-THA1250PnP.html?tp=115
( by the way, this blau amp is a very good example of an old saying ""Good Things Come in Small Packages"" )
Victor...
PS: You could pick up sub + amp combo from any reputed manufacturer. just see that the sub is a 10" capable of performing in a small sealed enclosure and can take around 300wrms power, paired with a simple but performing monoblock ....
swez on 01/7/2009 06:56:23
This is just way to much fun to observe, but for the sake of others, we can stop now. I see the same patterns of responses that all point in one general direction...
"Fit the speakers to the acoustical environment that we are working in". That's always easier said than done. Audio Engineers are now part of the early design team for premium sound systems in upscale cars. (It's about time as this was just an after-thought a few years back)
The tough part here, they optimize the system around general parameters that do not suit all music genres well, but do a good job in a narrow scope of music/audio the target buyer will use most. I'll say this... it ain't Rap and not just Talk Radio, Jazz, Classical, Soft Rock or NPR, but something that does the latter 5 well. Rap suffers in the end. (Not the targeted audience for Audi, Jaguar, BMW, Caddy, Lincoln and other)
If you drive one of these and love Rap or Hip Hop, plan on ripping out the whole system and start from scratch !
Swez COFFEE
Ash on 01/10/2009 06:24:29
You're on spot here Swez. This debate is to no avail. The aspect that needs attention is the different genres that will be listened to. In this case I would suggest any woofer capable of F3's in the 50-70hz range but in a low Qtc sealed box (.707).
Small subs (8-10") mate better in small hatch cars and low to medium power (150-200 rms) if all else is powered by the HU. This is pretty straightforward, but don't expect perfection with all music. A built-in EQ in the HU will help with the genres styles.
swez on 01/10/2009 09:31:24
LOL
Three bright people in room, analyzing a simple concept to the Nth degree, all coming at the plan from various angles and arriving at the same conclusion. Amazing feat all by itself huh?
Vic's database idea makes a lot of sense for high end customers. Ash's methodology would help you get there. By removing as many minor variables as possible, one could profile a vehicle in short order with much practice.
It's been fun guys,
Dave
Victor on 01/10/2009 09:47:32
3 bright people .... !
Whose the 3rd one ??? GRIN
swez on 01/10/2009 10:11:33
The quiet guy in the corner that's reading all this jibber-jabber and says nothing. He is the wise one!
Well, we got some fresh snow last night and it's high time to get out there and deal with it. Whoopie! (-5 C; winds NE 20kph; 3-5" of new snow at 10:00 am; 1/10/2009)
Swez
Ash on 01/10/2009 20:45:52
Whoopie?!!! Between the minor cold snaps, luke warm weather breaks, and lying weathermen our spotted sea trout fishing season is pretty much over. We had some major cold weather come in early about 1.5 months ago that had everyone thinking this was going to be a good winter for trout and now it's ruined. It ends the 1st of Feburary and there's no way the water will get cold enough before then for it to be worth it. The pawn shops are full of fishing gear!
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