Comp's MM6501

arun1963

TakeTheTime wrote: »

And arun, I know I took it a little far - but my point was, that mounting/sounddeadening is very important too...

Relax, I know what you were saying. Was just yanking your chain a bit .

Great sound in a car is, 50% tuning, 25% install and 25% equipment, give or take a bit.

Yet, there is so much time, effort and energy wasted in arguing about the sq properties of Brand A vs Brand B. Expensive amps don't sound better. Speakers do sound different though. Are Focal utopias better than the SR's? Depends on what your ears like. To get the best out of any speaker in a car, you're going to have to tune it. DSP is critical and the more you have of it the better.

To my mind, install covers placement, secure mounting, deadening and managing reflection to the extent that you can. It's fairly basic, except the reflections bit which is a PITA.

Tuning though is the key. Yes, you can tune a pair of sony xplod components to sound great, but if you used the same tuning tools on a pair of sr's......

Mac runs a 3-4K system, with a home install and was 0.2 points from the championship last year. Thats got to tell you something.

KaosTsoc

TakeTheTime wrote: »

Sounds good! Other good choices for front speakers? DLS is a good choice, I think.
But since you're at the Polk-forum, I think you should go for Polk speakers. It's good ya!

And arun, I know I took it a little far - but my point was,
that mounting/sounddeadening is very important too...

Thank you for that I will take a look. No worries to me about the sound deading part either. I plan on doing the whole truck interior, but man it is a p.i.t.a. it will be worth it in th end.

Thanks

KaosTsoc

DSkip wrote: »

One thing you will find about this site is it is less based on what you use, and more focused on the application and knowledge behind the audio. Everyone still has their preferences, and this is obviously a Polk-heavy forum (imagine that), but the members are pretty solid about offering their opinions without throwing in the bashing. I think that has more to do with the maturity of our members. My impression has been that this is a relatively older forum compared to other forums out there.

This is very true. I read this forum, and some of the posts on here, and several other sites befor I decided to go with one, looked around for a good two months. I like what the people have to say on here, it is.... very.....knowledgeable. Plus I have the DB series 6 1/2 coax currently so, I am a polk fan as well. However I still like to get other ideas on other brands. You never know what is out there until you take a look, or ask.

Thanks.

KaosTsoc

arun1963 wrote: »

Relax, I know what you were saying. Was just yanking your chain a bit .

Great sound in a car is, 50% tuning, 25% install and 25% equipment, give or take a bit.

Yet, there is so much time, effort and energy wasted in arguing about the sq properties of Brand A vs Brand B. Expensive amps don't sound better. Speakers do sound different though. Are Focal utopias better than the SR's? Depends on what your ears like. To get the best out of any speaker in a car, you're going to have to tune it. DSP is critical and the more you have of it the better.

To my mind, install covers placement, secure mounting, deadening and managing reflection to the extent that you can. It's fairly basic, except the reflections bit which is a PITA.

Tuning though is the key. Yes, you can tune a pair of sony xplod components to sound great, but if you used the same tuning tools on a pair of sr's......

Mac runs a 3-4K system, with a home install and was 0.2 points from the championship last year. Thats got to tell you something.

Yes alot of people argue on forums about this, or that, brand A is better than brand B no matter what you say etc etc. And that is just not me.

Like I have said to my self, if I am going to now take the time to do this car audio system right this time I am going to go out, and ask questions, look at products (listen to them if I can) so on and, so on. I am not looking to go competition grade or anything, but would like to have a quality sound stage. That can not only be articulate, but get laud, and low, and hit hard when I want to. So, that goes back to preperation, installation, and tuning. Which is where I am at now.

Thanks.

KaosTsoc

I have a good question for you all. I know I probably should have asked this befor, but when looking at the tech spec's what am I looking for?? What I mean by that is; how can I tell if the comps are set up to be more SQL driven, or SPL driven. Am I suppossed to look at the freq response?? Also what is a good freq response that is a good starting point.

Also if you all could please take a look at my other thread I would greatly appreciate it.

http://www.polkaudio.com/forums/showthread.php?t=104602

This is about my sub selection. I like to keep the topics seperate, I have A.D.D. and this helps me keep a better track of things.

Thanks.

arun1963

Its easier to just try and listen and then decide. More accurate too.

http://www.bcae1.com/

www.the12volt.com

Thiele small parameter numbers. Both sites have a good information. Numbers are only a broad reference point. Don't get caught up evaluating speakers based on numbers. I've heard good sound from speakers that had just average numbers and vice versa.

SivaNevets

KaosTsoc wrote: »

I have a good question for you all. I know I probably should have asked this befor, but when looking at the tech spec's what am I looking for?? What I mean by that is; how can I tell if the comps are set up to be more SQL driven, or SPL driven. Am I suppossed to look at the freq response?? Also what is a good freq response that is a good starting point.

Also if you all could please take a look at my other thread I would greatly appreciate it.

http://www.polkaudio.com/forums/showthread.php?t=104602

This is about my sub selection. I like to keep the topics seperate, I have A.D.D. and this helps me keep a better track of things.

Thanks.

SQL is subjective to individuals. for SPL, power handling+sensitivity will give u a good idea how loud it can play

KaosTsoc

SivaNevets wrote: »

infnity kappa components also sound decent for me at this price range..what kind of music you listen to?

I listen to heavy metal, and hard core hip, and rap. nothing in between that.

I have looked at infinity kappa, but have not had a chance to hear their comps. I did hear their coax, and thought they lacked the mid bass that I am looking for. I will try to see if I can find a store around here that has their comps and see what they sound like.

Thanks.

KaosTsoc

arun1963 wrote: »

Its easier to just try and listen and then decide. More accurate too.

http://www.bcae1.com/

www.the12volt.com

Thiele small parameter numbers. Both sites have a good information. Numbers are only a broad reference point. Don't get caught up evaluating speakers based on numbers. I've heard good sound from speakers that had just average numbers and vice versa.

Thank you, I like the bcae1 website. That is where I learned some of the info that I know now. The only bad thing about the website though is that who ever took the time write all that stuff made it a little to technical for me, and kind of would lose focus after a while.

As for the the12volt website, that is also a good one as well. It has a lot of pic's that kinda show you how it all works. Thanks for the suggestions.


Thanks

SivaNevets

KaosTsoc wrote: »

I listen to heavy metal, and hard core hip, and rap. nothing in between that.

I have looked at infinity kappa, but have not had a chance to hear their comps. I did hear their coax, and thought they lacked the mid bass that I am looking for. I will try to see if I can find a store around here that has their comps and see what they sound like.

Thanks.

havent got chance to listen to the sr series, but mm6501 is clearly the best components for the kind of music u listed under $500 cap ive heard (you want a great dynamics). (apline,mtx,infinity,focal,rockford,pioneer,clarion)

focal polyglass is lacking midbass as well. but i really like the mids and highs, very airy. bright yet not fatiguing

KaosTsoc

SivaNevets wrote: »

SQL is subjective to individuals. for SPL, power handling+sensitivity will give u a good idea how loud it can play

This is ture...... SQL to me is like trying to reproduce the sound I get out of my headphones, as far as getting the small detail.

Thank you for telling my that. Now what is a good starting point, for sensitivity, as for power handeling this is kind of subjective right?? I mean just cause it can handle alot of power does not mean that it can get laud, and vise versa right?? kind of confused here a little.

Really I kind of have to go by the tech spec because, alot of the stores around my area just do not carry these products, and the products they do carry are more for the everyday man, not for the audiopile like myself, or you all. And the stores that do carry them are sometimes an hour and half or more away from me. I cant really justify driving 2-3 hours to listen to speakers, if it was like an hour or so then yeah I can deal with that. That is just me. I guess if I have to I will, but seriously......

Thanks

KaosTsoc

SivaNevets wrote: »

havent got chance to listen to the sr series, but mm6501 is clearly the best components for the kind of music u listed under $500 cap ive heard (you want a great dynamics). (apline,mtx,infinity,focal,rockford,pioneer,clarion)

focal polyglass is lacking midbass as well. but i really like the mids and highs, very airy. bright yet not fatiguing

Have not heard the SR's either.... YET. I am setting some time aside to get with dskip, and listen to his set, and see what I think. I will let you know my thoughts.

Yeah, I am really looking for a set of comps that have plenty of mid bass, but also good dynamics. I was thinking of going with RF T1 comps, but they are on the back end of the spectrum. Focal will be a little to steep in price for me or at least for the one's that I would buy form them. MTX states that their product is good, but I wounder how articulat they are. Hmmmm...... Alpine is pretty well known, and people swear by them, but there again I did not hear any mid bass. They almost to me sounded like the coax DB that I currently have. Pioneer dont really know much about, but then again I never used them, I will take a look. As for clarion, I have never heard of their speakers at all. I have a head unit from them, and like thus far, but have not really heard anything about their speakers.

Thanks.

SivaNevets

KaosTsoc wrote: »

This is ture...... SQL to me is like trying to reproduce the sound I get out of my headphones, as far as getting the small detail.

Thank you for telling my that. Now what is a good starting point, for sensitivity, as for power handeling this is kind of subjective right?? I mean just cause it can handle alot of power does not mean that it can get laud, and vise versa right?? kind of confused here a little.

Really I kind of have to go by the tech spec because, alot of the stores around my area just do not carry these products, and the products they do carry are more for the everyday man, not for the audiopile like myself, or you all. And the stores that do carry them are sometimes an hour and half or more away from me. I cant really justify driving 2-3 hours to listen to speakers, if it was like an hour or so then yeah I can deal with that. That is just me. I guess if I have to I will, but seriously......

Thanks

sensitivity/efficiency is measured by dB per watt at 1 min , a speaker with 94dB will play louder, thus more SPL than a 91dB with identical power, SPL is objective measurement. but does not equvalent to "sound better", for example, mm6501 is more efficient than db6501, means it will play louder with identical power, but lets say they both underpowered with 10 rms head unit, mm6501 still plays louder, more SPL, but unbalanced, distorted sound, hence SQL is hard to measure.

max power handling is also objective. more power handling then louder it capable to play.

---

ill quote something from wikipedia.

Efficiency vs. sensitivity
Loudspeaker efficiency is defined as the sound power output divided by the electrical power input. Most loudspeakers are actually very inefficient transducers; only about 1% of the electrical energy sent by an amplifier to a typical home loudspeaker is converted to acoustic energy. The remainder is converted to heat, mostly in the voice coil and magnet assembly. The main reason for this is the difficulty of achieving proper impedance matching between the acoustic impedance of the drive unit and that of the air into which it is radiating (at low frequencies improving this match is the main purpose of speaker enclosure designs). The efficiency of loudspeaker drivers varies with frequency as well. For instance, the output of a woofer driver decreases as the input frequency decreases because of the increasingly poor match between air and the driver.

Driver ratings based on the SPL for a given input are called sensitivity ratings and are notionally similar to efficiency. Sensitivity is usually defined as so many decibels at 1 W electrical input, measured at 1 meter, often at a single frequency. The voltage used is often 2.83 VRMS, which is 1 watt into an 8 Ω (nominal) speaker impedance (approximately true for many speaker systems). Measurements taken with this reference are quoted as dB with 2.83 V @ 1 m.

The sound pressure output is measured at (or mathematically scaled to be equivalent to a measurement taken at) one meter from the loudspeaker and on-axis (directly in front of it), under the condition that the loudspeaker is radiating into an infinitely large space and mounted on an infinite baffle. Clearly then, sensitivity does not correlate precisely with efficiency, as it also depends on the directivity of the driver being tested and the acoustic environment in front of the actual loudspeaker. For example, a cheerleader's horn produces more sound output in the direction it is pointed by concentrating sound waves from the cheerleader in one direction, thus "focusing" them. The horn also improves impedance matching between the voice and the air, which produces more acoustic power for a given speaker power. In some cases, improved impedance matching (via careful enclosure design) will allow the speaker to produce more acoustic power.

Typical home loudspeakers have sensitivities of about 85 to 95 dB for 1 W @ 1 m—an efficiency of 0.5–4%.
Sound reinforcement and public address loudspeakers have sensitivities of perhaps 95 to 102 dB for 1 W @ 1 m—an efficiency of 4–10%.
Rock concert, stadium PA, marine hailing, etc. speakers generally have higher sensitivities of 103 to 110 dB for 1 W @ 1 m—an efficiency of 10–20%.
A driver with a higher maximum power rating cannot necessarily be driven to louder levels than a lower-rated one, since sensitivity and power handling are largely independent properties. In the examples that follow, assume (for simplicity) that the drivers being compared have the same electrical impedance; are operated at the same frequency within both driver's respective pass bands; and that power compression and distortion are low. For the first example, a speaker 3 dB more sensitive than another will produce double the sound pressure level (or be 3 dB louder) for the same power input; thus, a 100 W driver ("A") rated at 92 dB for 1 W @ 1 m sensitivity will put out twice as much acoustic power as a 200 W driver ("B") rated at 89 dB for 1 W @ 1 m when both are driven with 100 W of input power. In this particular example, when driven at 100 W, speaker A will produce the same SPL, or loudness, that speaker B would produce with 200 W input. Thus, a 3 dB increase in sensitivity of the speaker means that it will need half the amplifier power to achieve a given SPL. This translates into a smaller, less complex power amplifier—and often, to reduced overall system cost.

It is not possible to combine high efficiency (especially at low frequencies) with compact enclosure size and adequate low frequency response. One can, more or less, choose only two of the three parameters when designing a speaker system. So, for example, if extended low-frequency performance and small box size are important, one must accept low efficiency.[33] This rule of thumb is sometimes called Hoffman's Iron Law (after J.A. Hoffman, the "H" in KLH).[34]

arun1963

KaosTsoc wrote: »

Have not heard the SR's either.... YET. I am setting some time aside to get with dskip, and listen to his set, and see what I think. I will let you know my thoughts.

Hook up with DSkip. I'm sure you'll get to hear good sound. You'll like the sr's.

KaosTsoc

SivaNevets wrote: »

sensitivity/efficiency is measured by dB per watt at 1 min , a speaker with 94dB will play louder, thus more SPL than a 91dB with identical power, SPL is objective measurement. but does not equvalent to "sound better", for example, mm6501 is more efficient than db6501, means it will play louder with identical power, but lets say they both underpowered with 10 rms head unit, mm6501 still plays louder, more SPL, but unbalanced, distorted sound, hence SQL is hard to measure.

max power handling is also objective. more power handling then louder it capable to play.

---

ill quote something from wikipedia.

Efficiency vs. sensitivity
Loudspeaker efficiency is defined as the sound power output divided by the electrical power input. Most loudspeakers are actually very inefficient transducers; only about 1% of the electrical energy sent by an amplifier to a typical home loudspeaker is converted to acoustic energy. The remainder is converted to heat, mostly in the voice coil and magnet assembly. The main reason for this is the difficulty of achieving proper impedance matching between the acoustic impedance of the drive unit and that of the air into which it is radiating (at low frequencies improving this match is the main purpose of speaker enclosure designs). The efficiency of loudspeaker drivers varies with frequency as well. For instance, the output of a woofer driver decreases as the input frequency decreases because of the increasingly poor match between air and the driver.

Driver ratings based on the SPL for a given input are called sensitivity ratings and are notionally similar to efficiency. Sensitivity is usually defined as so many decibels at 1 W electrical input, measured at 1 meter, often at a single frequency. The voltage used is often 2.83 VRMS, which is 1 watt into an 8 Ω (nominal) speaker impedance (approximately true for many speaker systems). Measurements taken with this reference are quoted as dB with 2.83 V @ 1 m.

The sound pressure output is measured at (or mathematically scaled to be equivalent to a measurement taken at) one meter from the loudspeaker and on-axis (directly in front of it), under the condition that the loudspeaker is radiating into an infinitely large space and mounted on an infinite baffle. Clearly then, sensitivity does not correlate precisely with efficiency, as it also depends on the directivity of the driver being tested and the acoustic environment in front of the actual loudspeaker. For example, a cheerleader's horn produces more sound output in the direction it is pointed by concentrating sound waves from the cheerleader in one direction, thus "focusing" them. The horn also improves impedance matching between the voice and the air, which produces more acoustic power for a given speaker power. In some cases, improved impedance matching (via careful enclosure design) will allow the speaker to produce more acoustic power.

Typical home loudspeakers have sensitivities of about 85 to 95 dB for 1 W @ 1 m—an efficiency of 0.5–4%.
Sound reinforcement and public address loudspeakers have sensitivities of perhaps 95 to 102 dB for 1 W @ 1 m—an efficiency of 4–10%.
Rock concert, stadium PA, marine hailing, etc. speakers generally have higher sensitivities of 103 to 110 dB for 1 W @ 1 m—an efficiency of 10–20%.
A driver with a higher maximum power rating cannot necessarily be driven to louder levels than a lower-rated one, since sensitivity and power handling are largely independent properties. In the examples that follow, assume (for simplicity) that the drivers being compared have the same electrical impedance; are operated at the same frequency within both driver's respective pass bands; and that power compression and distortion are low. For the first example, a speaker 3 dB more sensitive than another will produce double the sound pressure level (or be 3 dB louder) for the same power input; thus, a 100 W driver ("A") rated at 92 dB for 1 W @ 1 m sensitivity will put out twice as much acoustic power as a 200 W driver ("B") rated at 89 dB for 1 W @ 1 m when both are driven with 100 W of input power. In this particular example, when driven at 100 W, speaker A will produce the same SPL, or loudness, that speaker B would produce with 200 W input. Thus, a 3 dB increase in sensitivity of the speaker means that it will need half the amplifier power to achieve a given SPL. This translates into a smaller, less complex power amplifier—and often, to reduced overall system cost.

It is not possible to combine high efficiency (especially at low frequencies) with compact enclosure size and adequate low frequency response. One can, more or less, choose only two of the three parameters when designing a speaker system. So, for example, if extended low-frequency performance and small box size are important, one must accept low efficiency.[33] This rule of thumb is sometimes called Hoffman's Iron Law (after J.A. Hoffman, the "H" in KLH).[34]

Wow...Ok..... So let me get this straight. The higher the DB is at 1w/1m means it leans more towards spl, and the less DB the more it leans toward SQL regardless of power handleing..??

Thanks.

SivaNevets

KaosTsoc wrote: »

Wow...Ok..... So let me get this straight. The higher the DB is at 1w/1m means it leans more towards spl, and the less DB the more it leans toward SQL regardless of power handleing..??

Thanks.

you cant really tell SQL from reading statics. as sound quality is often based on individual preferrence..

SQL is not really a technical term.. SPL is.

KaosTsoc

SivaNevets wrote: »

you cant really tell SQL from reading statics. as sound quality is often based on individual preferrence..

SQL is not really a technical term.. SPL is.

Ah, my bad. Still new to these terms. So, am I correct in my thoughts that I posed..??



Thanks.

SivaNevets

KaosTsoc wrote: »

Wow...Ok..... So let me get this straight. The higher the DB is at 1w/1m means it leans more towards spl, and the less DB the more it leans toward SQL regardless of power handleing..??

Thanks.

i think u got the first part right.
generally u cant really tell sound quality (SQL) from specs, a high end speaker can be either efficient or not efficient.

KaosTsoc

SivaNevets wrote: »

i think u got the first part right.
generally u cant really tell sound quality (SQL) from specs, a high end speaker can be either efficient or not efficient.

Cool deal. Thanks for that info. It kind of sucks that the manufactures always embellish the specs a little so, that does not help. I guess it really comes down to preperation, installation (deading etc), and what I think sounds best to my ears. Thank you though.


Thanks.

frosty2k

SivaNevets wrote: »

SQL is not really a technical term.. SPL is.

Correct me if I'm wrong, but to clearly define these, I believe that SPL is a measurable quantity that is usually related to the output volume of a speaker in decibels.

In competition, SPL has become synonymous with the extreme high volume subwoofer power competitions, and SQL is the term for the competition in the still loud, but generally lower volume, maximum sound clarity group. SQL is not actually a measurable amount, unless you count a judge's score as a measurement.

I think the only written specification that might indicate SQL is usually SnR (signal to noise ratio) which is generally high for SQL, or THD (total harmonic distortion) which is generally low for SQL. I think these are usually on electronics, not speakers though.

arun1963

Time out guys.

1. Sensitivity: Typically it should be a decibel value measured at 1 metere at 1 watt of power. But almost 100% of the sensitivity numbers tossed about for speakers mention, 'x' db at 2.83 volts measured at 1 metre. This is fine for home audio drivers not so for car speakers.

Going back to your high school physics, P=E^2/R. Where P=Power, E is the voltage and R is the impedence of the driver. Most home audio drivers are rated at 8ohms. So a signal of 2.83 volts to a speaker with an impedence of 8 ohms will yield 1 watt. But most car speakers are 4 ohms. Now the same voltage will yield how many watts? Correct, you're now measuring output at 2 watts. Basic rule of thumb, if you double the power the sound level goes up by 3 db. So in most cases you have to subtract this 3 db from the published figure.

A couple of other twists. The measuring is done at a particular frequency. Typically around the 1khz mark. Will the response be the same across all frequencies? Heck no.

Measurement is done with speakers in an enclosure, in a room, not installed in a car. The minute you install the speaker in the car, its a whole new ball game.

Here are some typical sensitivity numbers, all measured at the same 2.83v/1metre:

Polk SR 6500 - 92db 125W rms
Morel Elate - 87db 200W rms
Sony Explod - 90db 60W rms

So what do the sensitivity numbers by themselves tell me? At the end of the day, ZILCH. The first two are amazing speakers the third is pure crap. I've tossed in RMS numbers just to stir the pot a bit.

2. Frequency Response: Much discussed and argued over, to prove Brand A is better than Brand B. Most manufacturers will claim +/- 2-3db variance over a range lets say 80-20khz. Again this is measured in a room / board / non car environment. I will eat my dirty smelly sneakers if ANY speaker in the world can give me a +/- 3db response from 80-20Khz in a car :cool:.

Just not going to happen. You can get to about +/- 4-5dbs with tons of dsp, but stock install? Heck no. Simple exercise, if you have a disc with test tones set everything flat at your hu and listen to the test tones. Chances are 500-3khz will be the loudest and maybe like +8 to 10db from say the 100-300 range. So much for the frequency response numbers. The only thing I take from the typical frequency response graphs is to note roll off points as that is a bit relevant for xover points and to see if the driver has any sharp peaks or dips at a particular frequency. Other than that these numbers and graphs mean ZILCH.

Sound is not a numbers game. Numbers at best can only give you an idea. The best way to test a speaker is to listen to it. That said there are some numbers, thiele small parameters, numbers like liner xmax, Le, Qts etc that have a bit more relevance, but even with these, the numbers are only indications. That lesson would be Speaker Numbers - 201 .

catch22atplay

Rockford T2652-S shows a low of 83db at 340hz and a high of 97.5db at 16khz on axis. A low of 80db at 340hz and a high of 100.5db at 18khz 30 degrees off axis. And that's not in a car. However they were using summed Far-Field and Near-Field IEC60268-5 baffle measurements. I thought that applied to cell phone speakers and the like. But what do i know. Rockford is not known for SQ component speakers. Nuff said on that subject.

KaosTsoc

frosty2k wrote: »

Correct me if I'm wrong, but to clearly define these, I believe that SPL is a measurable quantity that is usually related to the output volume of a speaker in decibels.

In competition, SPL has become synonymous with the extreme high volume subwoofer power competitions, and SQL is the term for the competition in the still loud, but generally lower volume, maximum sound clarity group. SQL is not actually a measurable amount, unless you count a judge's score as a measurement.

I think the only written specification that might indicate SQL is usually SnR (signal to noise ratio) which is generally high for SQL, or THD (total harmonic distortion) which is generally low for SQL. I think these are usually on electronics, not speakers though.

Ok. Cool deal, this will help me in the amp dept. Thanks.

I guess the judges score could be a measurement, but that is also subjective. Hmmmm........

Thanks.

KaosTsoc

arun1963 wrote: »

Time out guys.

1. Sensitivity: Typically it should be a decibel value measured at 1 metere at 1 watt of power. But almost 100% of the sensitivity numbers tossed about for speakers mention, 'x' db at 2.83 volts measured at 1 metre. This is fine for home audio drivers not so for car speakers.

Going back to your high school physics, P=E^2/R. Where P=Power, E is the voltage and R is the impedence of the driver. Most home audio drivers are rated at 8ohms. So a signal of 2.83 volts to a speaker with an impedence of 8 ohms will yield 1 watt. But most car speakers are 4 ohms. Now the same voltage will yield how many watts? Correct, you're now measuring output at 2 watts. Basic rule of thumb, if you double the power the sound level goes up by 3 db. So in most cases you have to subtract this 3 db from the published figure.

A couple of other twists. The measuring is done at a particular frequency. Typically around the 1khz mark. Will the response be the same across all frequencies? Heck no.

Measurement is done with speakers in an enclosure, in a room, not installed in a car. The minute you install the speaker in the car, its a whole new ball game.

Here are some typical sensitivity numbers, all measured at the same 2.83v/1metre:

Polk SR 6500 - 92db 125W rms
Morel Elate - 87db 200W rms
Sony Explod - 90db 60W rms

So what do the sensitivity numbers by themselves tell me? At the end of the day, ZILCH. The first two are amazing speakers the third is pure crap. I've tossed in RMS numbers just to stir the pot a bit.

2. Frequency Response: Much discussed and argued over, to prove Brand A is better than Brand B. Most manufacturers will claim +/- 2-3db variance over a range lets say 80-20khz. Again this is measured in a room / board / non car environment. I will eat my dirty smelly sneakers if ANY speaker in the world can give me a +/- 3db response from 80-20Khz in a car :cool:.

Just not going to happen. You can get to about +/- 4-5dbs with tons of dsp, but stock install? Heck no. Simple exercise, if you have a disc with test tones set everything flat at your hu and listen to the test tones. Chances are 500-3khz will be the loudest and maybe like +8 to 10db from say the 100-300 range. So much for the frequency response numbers. The only thing I take from the typical frequency response graphs is to note roll off points as that is a bit relevant for xover points and to see if the driver has any sharp peaks or dips at a particular frequency. Other than that these numbers and graphs mean ZILCH.

Sound is not a numbers game. Numbers at best can only give you an idea. The best way to test a speaker is to listen to it. That said there are some numbers, thiele small parameters, numbers like liner xmax, Le, Qts etc that have a bit more relevance, but even with these, the numbers are only indications. That lesson would be Speaker Numbers - 201 .

Holy crap.. That must have taken some time to type that up. Man.... This is so helpful. I am getting to understand this more, and more.


Thanks.

KaosTsoc

catch22atplay wrote: »

Rockford T2652-S shows a low of 83db at 340hz and a high of 97.5db at 16khz on axis. A low of 80db at 340hz and a high of 100.5db at 18khz 30 degrees off axis. And that's not in a car. However they were using summed Far-Field and Near-Field IEC60268-5 baffle measurements. I thought that applied to cell phone speakers and the like. But what do i know. Rockford is not known for SQ component speakers. Nuff said on that subject.

Good to know. I was thinking of going with their T1 series, but after looking around, it seems that polk, DLS (which I looked at online, and they look nice) and Morel (there are more I am sure I did not list) seem to well completely blow them out of the water. Glad you said something because, I might have put them on my list. Now removed lol.

Thanks.

arun1963

catch22atplay wrote: »

Rockford T2652-S shows a low of 83db at 340hz and a high of 97.5db at 16khz on axis. A low of 80db at 340hz and a high of 100.5db at 18khz 30 degrees off axis. And that's not in a car.

Precisement. Now, if you install the said Rockford T2652-S in your car and do the test tone experiment with an spl meter you may wind up with something like:

On Axis : 340hz - 92db, 16khz - 78 db
Off Axis : 340 hz - 86db, 16 khz - 75 db

Your ears, more or less would tell you the same thing. Numbers measured outside the car mean nothing, cause I'm hearing the speakers in the car. Try the test tones exercise. 800-8khz is the loudest in a car. Again thas for your and my older ears. For the young 'uns here maybe the roll off would start at 10. even for the 16khz would not be the loudest.

If you tried to balance out all the frequencies, so that they all sounded the same level, you would end up with the boom box sound. Or worse dull lifeless sound. When I had my sr's and things were dialed in well, the spl rose gradually from 50hz to 500hz. 50hz and 80hz though were way lower than 500hz.

The rise continues from 800-3khz. The sr's have a peak around the 800khz mark which needs a major cut. But the brightest frequencies in this range is 1.25-3khz.

With the tweeter gains set at -8db for left and right, the roll off starts around the 6khz mark. just for a lark if I set the tweet gains to 0/0, the roll off starts around 8khz, 12 is lower, 16khz is way lower.

KaosTsoc

arun1963 wrote: »

Precisement. Now, if you install the said Rockford T2652-S in your car and do the test tone experiment with an spl meter you may wind up with something like:

On Axis : 340hz - 92db, 16khz - 78 db
Off Axis : 340 hz - 86db, 16 khz - 75 db

Your ears, more or less would tell you the same thing. Numbers measured outside the car mean nothing, cause I'm hearing the speakers in the car. Try the test tones exercise. 800-8khz is the loudest in a car. Again thas for your and my older ears. For the young 'uns here maybe the roll off would start at 10. even for the 16khz would not be the loudest.

If you tried to balance out all the frequencies, so that they all sounded the same level, you would end up with the boom box sound. Or worse dull lifeless sound. When I had my sr's and things were dialed in well, the spl rose gradually from 50hz to 500hz. 50hz and 80hz though were way lower than 500hz.

The rise continues from 800-3khz. The sr's have a peak around the 800khz mark which needs a major cut. But the brightest frequencies in this range is 1.25-3khz.

With the tweeter gains set at -8db for left and right, the roll off starts around the 6khz mark. just for a lark if I set the tweet gains to 0/0, the roll off starts around 8khz, 12 is lower, 16khz is way lower.

Cool deal. Thank you much for that.

Thanks.

KaosTsoc

DSkip wrote: »

I want to make a public apology to Kaos. He was supposed to hear the SR's today and I had to back out on short notice. We got home today after shopping for a Digital SLR Camera (to document said boy's life) and checked the mail, only to find $6,000 worth of medical bills from my boy's birth a month ago. This was about 90 minutes before the time we set, and with the sudden jump in stress and the immediate need to research, I backed out.

We will be setting up another time later in the week, possibly after this issue has been resolved. I know most don't care and this is mostly directed at Kaos. It also feels good to vent some as I'm still feeling the stress 3 hours later.

Thank you sir, and no worries. I understand, and you know what... life happens. I had to back out on the other guy that I was supposed to meet as well, but had to take my mom to the ER (she is fine, and good to go) so, yeah its cool.

On a positive note you have a healty baby boy, and that is so much more worth it in the end. You have to vent at some point to someone other than your significant other. Its just one of those things.. Its life..:)

Thanks

arun1963

DSkip wrote: »

How do you go about cutting that frequency? My EQ only goes up to around 12.5 khz

That was posted at 11:30 at night after a few....hey, nobodys perfect. Me least of all.

DSkip wrote: »

I want to make a public apology to Kaos......

That was a nice gesture. Yeah get ready for non stop flow of bills. How much of the bill is covered by your medical insurance?

KaosTsoc

arun1963 wrote: »

That was posted at 11:30 at night after a few....hey, nobodys perfect. Me least of all.



That was a nice gesture. Yeah get ready for non stop flow of bills. How much of the bill is covered by your medical insurance?

This is true. True in deed.

Thanks.