MOMO vs. old DB & EX2 Series listening

["Polk" Paul DiComo]

This is really a continuation of or response to the thread "I just had to comment." That thread got too long and sort of degenerated a bit at the end so I thought I'd start a new one.

Thanks to all of you who reminded us that it is always a good idea to listen to new models vs. old models that go back more than a generation. It is a good thing to do and we need to do it more often.

Al Ballard, Kim Jasper and I set up some comparison listening and here is an interim report. I say interim because we have not yet set up comparisons of new component systems vs. original DB Series component systems. This is what we found when listening to coaxials. All three of us have the same opinion on what we heard.

db650 ($120/pr) vs. EX602a ($110/pr) – The EX602a was slightly more efficient then the db650 and played a little louder for a given volume setting, but had obvious bass distortion at a high volume level. The EX602a was far more projected or "forward" in the upper midrange to the point of being "shouty," aggressive and annoying at high levels. Hard and reflective panels such as plastic door panels, dashboards, and glass windows that one finds in cars tend to accentuate this aggressive midrange characteristic. The db650 midrange was smoother and more natural in the midrange as one would expect given that it uses LP and HP crossovers while the EX has only a HP filter. Frequency response measurements confirm that the db650 has flatter response in that region. High frequency and bass extension was about the same but the db imaging was better – more open and spacious. Again, that is just as one would expect given the crossover differences and the measurements. We all agreed however that some listeners might prefer the more forward, aggressive midrange of the EX. It is all a matter of what one expects from a speaker. Some people don’t like "flat" and that's OK.

Cosmetically the new db650 won hands down – and in my car cosmetics do count. But this is not to say that the EX602a was a bad sounding speaker. Heard at moderate listening levels without a direct comparison, we found it very good sounding, easily comparable to typical coxials in the $100 - $130 range.
OUR VERDICT: db650 by a knockout

db650 ($120/pr) vs. db6520 ($220/pr.) – Just for jollies we decided to compare the new db vs. the original db coaxials even though they are not directly comparable in price. The old db has deeper bass – not surprising since that was an oversized 6.5" driver – in fact that was a big problem with that model – it didn't fit standard 6.5" holes. The old db also had better highs, more extended and brighter – to be expected give that it uses a full 1 inch tweeter while new db has a 3/4 inch. But in the midrange again the new db had the edge in smoothness and accuracy. It wasn't as big a difference as in the EX602a vs. new db comparison but it was clearly audible. New db had a slight edge in imaging and spaciousness.
Cosmetics were no contest – new db looks way nicer and it actually fits in cars without cutting!

OUR VERDICT: Slight edge to old db on absolute performance, edge to new db on value and convenience

MOMO MMC650 ($200) vs. db6520 ($220) — The db625 was slightly more efficient playing a bit louder with the same volume setting. Again the db6520 had the edge in bass extension given the larger cone area. But in every other way the MMC625 was as good or better — highs were just as extended but a bit smoother and the midrange difference was dramatic. The MOMO midrange was smoother, more natural and was way better in the lower midrange. Male voices sounded a bit thin and shouty (a little forward or aggressive by comparison) on the db and richer, fuller and less strident on the MOMO. It is the kind of difference one would expect to hear in a coaxial vs. component comparison. That is to be expected as the MOMO coaxial has the external 2nd order crossover.

OUR VERDICT: MMC650 by decision

All this being said...if you have older db or EX Series speakers and you are happy with the sound of your car system, there is no need to buy the new products. What you have already is very good. But if you are in the market for new speakers anyway, you should give them a good listen. Listening is the bottom line. I can say with confidence that based on my listening these new products are a very good value when compared to our older product. As these products hit the stores we will be very interested to hear your impressions.

Further thought
It is worth pointing out that in addition to the sonic improvements we put in a lot of effort to ensure that these new speakers are very consumer and installer friendly. We have reduced the mounting depth along with the tweeter protrusion heights, and use a multi hole bolt patterns on the baskets to accommodate the mounting specifications of the majority of cars manufactured yesterday and today.

[Jstas]

Well geez, my hand are kind of tied on a response to this until I can get to hear the new stuff.

It's interesting though that you compared only coaxials. I'd be interested to see how component sets would compare. It's been my experience that component sets have a greater ability, not by much though, to produce a fuller, richer sound because of added cone support from dust caps. Believe it or not, my ears don't lie to me. I have big Dumbo ears and they hear things. Things that most people can only pick up with sophisticated listening equipment. I've even tested it to see if I was going nuts or something. My ears are as accurate as the listening equipment but I have an 85-90% accuracy rate. I just can't differentiate the numbers between minute differences, I can only acknowledge that they exist. It's kinda like Radar from M*A*S*H.

Anyway, my point is that coaxials sacrifice a percentage of space due to the post projecting from the center of the cone. I imagine that might affect sound. The reason is, even if the dust cap is squishy like on the original dB components, the ring of glue adds strength to the cone and the dust cap adds some surface area which can affect bass response. Also, coaxials have the tweeter directly over the cone of the woofer. While that is the ideal spot for a tweeter, it can cause deflection for the woofer and color sound and frequency response. A component set doesn't usually experience problems like that and makes it a different speaker all together.

Now, I'm not as well versed in the science behind it all like the engineers at Polk Audio. I am commenting through my own studies of the subject matter, experience and general knowledge picked up from others who have been around this stuff for like forever and a half. So please don't come down on me if I am not accurate with a statement. I want to learn.

So given all of that and my lack of financial resources to duplicate the tests present here already, I'd like to see what component sets would do comparing new to old. I think there may be a difference between the coaxials and the seperates from the component sets.

[Thom]

The problem is finding old dB stuff. It's been out of production for quite a while so there's none laying around. We could probably run DX vs. MM6. If we could find dB components I'm sure the MM6 would still win. A dB component set vs. a new Momo coax might be an interesting test, but the new Momo coax's are already less expensive than the dB coax's. I'm sure the even more expensive dB components should be slightly better than the dB coax's.

One of the biggest differences between coax's and components of the "same" line is the crossover. Most coax's don't low pass the mid, they only high pass the tweeter. (The new Momo coax's have outboard crossovers and even the new dB has a low passed mid.) Another difference can be the tweeter. A smaller tweeter is usually used on a coax, but you can get away with a larger one with a component set.

The actual placement makes less difference, I think. When Jessica started competing in IASCA in '98 she was using the (then brand new) MB Quart "Q" series. The tweeter was mounted coaxially over the center of the 6.5" mid in the kicks. She blew away even the second place competitor by more than 30 points. At finals that's insane. The judges even came back after judging was completed to bring by others to listen. I don't think the tweeters affected the mids whatsoever in that install. Obviously the bigger the tweeter the more chance of it changing the mids' sound, but the Q tweeters weren't the smallest tweeters.

[Jstas]

Well, I'd let you borrow my dB components but they are being used right now and due to the lack of availability, I cherish them too much to let even Polk Audio use them for fear of irrepairable damage occurring to them.

As far as placement goes, I wasn't refferring to volume or quality of sound being the reason for ideal placement. I was meaning imaging. If you look at a typical home speaker with a seperate tweeter and woofer, you can actually measure a small degree of seperation between highs and lows. I have read websites and other publications that show graphs and animations of tests where it can be seen that the best place for a tweeter is dead center in the middle of the woofer. I just wish I could find the URL's.

The reason for that is because the tweeter is directional while the woofer is somewhat non-directional. The lower the frequencies go, the more they radiate rather than "beam" for a lack of a better term.

Since the tweeters are directional, they can be localized easily. That localization can lead to sound stage and stereo imaging skewing. To minimize, almost eliminate that, the tweeter needs to be put as close to the center of the other half of the frequecy range's production source, i.e., the woofer.

The reason for the center is because the woofer's frequency production will radiate in all directions in a 180 degree arch from the center of the woofer, at an equal rate. Unless something, like a tweeter, impedes the progress. So if those frequencies radiate from teh center of the speaker at an even rate, the best place to put the tweeter would be the center of the woofer so that the tweeter's information radiates at the same rate and is much harder to localize because it is blended with the semi-non-directional woofer information. Does that make sense? I know what I mean but it can be hard to explain.

So that's what I mean about tweeters being an obstruction. While it is the perfect place for them, they can hinder the performance of the woofer in that respect. I imagine that due to the crossovers and such, Polk has managed to minimize the effect of woofer info reflecting off of the tweeter and mounting post. However, mounting a component tweeter in the same place may yeild different results. It can be hard to do that though so most people, including me, mount them side by side, woofer/tweeter. I was just thinking that the affect on imaging may cause enough of a difference to be noticable, wether it's good or bad.

[PoweredByDodge]

thom, you mentioned the outboard xovers on the new coax's...

while a "gooder" crossover is a great thing, and LP woof / HP tweet is all well and good, outboard sucks.

when we put my buddy's new speakers in his focus, he had gotten the alpines with the outboard xovers and it utterly made me crazy.

it eliminated the ability to be able to run your own type / size / brand speaker wire directly to the speaker... you have to run the 18 gauge or whatever comes with it from the xover to the speaker, and the fact that you've gotta have something half the size of a hockey puck floating around your car when u bought coax's for ease of install versus components just is a pain.

while i understand that a better crossover is gonna be larger and may need its own casing, i think it would be wise to at least attempt to somehow build it onto the back of the speaker basket.

if that shows complete impossibility then hey, oh well... but if its possible... u guys oughta think about tryin to get it on there...

it would also allow bi-amping with complete ease and no need for a crossover (besides the one on the speaker).

other idea would be to do it like a compont xover -- where u have the crossover all small and stuff but it has screw terminals for input and output.. that way users could use their own wiring to suit their tastes...

i mean if u're gonna take the extra money of building an external crossover, woudlnt' cost you any more to throw screw terminals on it and then package it without 20 feet of wire -- the cost of the wire would be replaced by the cost of the screw terminals...

just a thought.

[Thom]

Originally posted by PoweredByDodge
thom, you mentioned the outboard xovers on the new coax's...

while a "gooder" crossover is a great thing, and LP woof / HP tweet is all well and good, outboard sucks.

when we put my buddy's new speakers in his focus, he had gotten the alpines with the outboard xovers and it utterly made me crazy.

Depends on the crossover.


it eliminated the ability to be able to run your own type / size / brand speaker wire directly to the speaker... you have to run the 18 gauge or whatever comes with it from the xover to the speaker, and the fact that you've gotta have something half the size of a hockey puck floating around your car when u bought coax's for ease of install versus components just is a pain.

while i understand that a better crossover is gonna be larger and may need its own casing, i think it would be wise to at least attempt to somehow build it onto the back of the speaker basket.

if that shows complete impossibility then hey, oh well... but if its possible... u guys oughta think about tryin to get it on there...

It's impossible on these speakers in particular. The cast baskets are big and if you look at the components in the crossover case, there's no way we could have stuck them on the speaker.


it would also allow bi-amping with complete ease and no need for a crossover (besides the one on the speaker).

other idea would be to do it like a compont xover -- where u have the crossover all small and stuff but it has screw terminals for input and output.. that way users could use their own wiring to suit their tastes...

i mean if u're gonna take the extra money of building an external crossover, woudlnt' cost you any more to throw screw terminals on it and then package it without 20 feet of wire -- the cost of the wire would be replaced by the cost of the screw terminals...

This is just a $200 set of coax's. The most common installation by far will be throwing it in as quickly as possible (in retail every minute helps). The time it would take just to wire up crossovers with screw down terminals would be the longest part of the install. I prefer that style as well but if I was in retail and trying to make money the pre- wired style is MUCH quicker.

These new Momo crossovers also have little slots through the case so you don't have to screw them down (you can if you want), you can run a zip tie through them. No need for velcro.

:D

[PoweredByDodge]

zip ties make life easy....

are the xover cases "openable" -- like could a user pop it open (even if it meant slightly damaging the cosmetics of the xover case) and solder on new speaker wires inside?

just curious... cuz then, while it may void the warranty on the xover, it wud enable "ideal" useage.

[Thom]

Yes, the case snaps open. You have to open it if you want to screw it down. It's like some of our older crossovers, the top and bottom halves snap apart and the screws go through holes in the bottom half, than snap the top half back on. New speaker wire could be soldered on, but you might have to slightly enlarge the holes which the wire runs through.

[Thom]

Originally posted by Jstas


As far as placement goes, I wasn't refferring to volume or quality of sound being the reason for ideal placement. I was meaning imaging. If you look at a typical home speaker with a seperate tweeter and woofer, you can actually measure a small degree of seperation between highs and lows. I have read websites and other publications that show graphs and animations of tests where it can be seen that the best place for a tweeter is dead center in the middle of the woofer. I just wish I could find the URL's.

In theory, yes. But there's lots of different ways to make a car sound great.


The reason for that is because the tweeter is directional while the woofer is somewhat non-directional. The lower the frequencies go, the more they radiate rather than "beam" for a lack of a better term.

Since the tweeters are directional, they can be localized easily. That localization can lead to sound stage and stereo imaging skewing. To minimize, almost eliminate that, the tweeter needs to be put as close to the center of the other half of the frequecy range's production source, i.e., the woofer.

There have been many competitors over the years ( like Scott Buwalda, Mark Eldridge, and countless others) who've won show after show with tweeters in the a- pillars. In some systems these are the only tweeters, in others they're a second set. The benefits are higher, deeper, and wider soundstage. It doesn't work in every system (I'm not happy with the tweeters up high in Jessica's car- the stage is fine, but tonally something's not quite right), and it takes the proper crossover points to pull off. I remember a car years ago that had mids on the floor in front of the seat (aiming up between the passengers' legs) and tweeters on the doors aiming toward the windshield. People can make some weird looking set- ups sound great.

[sirogenous]

I cant believe what I'm hearing here. If a speaker is reproducing sound that sounds even the slightest bit different the the original source, then in theory the speaker isn't doing it's intended job. Do you really believe you can justify a speakers inability to reproduce sounds accurately by stating that some listeners prefer a speaker that has aggresive mids or a more punchy bass. It implies that perhaps polk is more interested in market trends then the accuracy of sound reproduction. One difficulty with building speakers is what humans hear vs. what we want or think we are hearing. It's all too subjective. Our brains are simply not set up to interpret audio information. In the animal world we are one of the worst as far as hearing performance.

[sntnsupermen131]

Originally posted by sirogenous
I cant believe what I'm hearing here. If a speaker is reproducing sound that sounds even the slightest bit different the the original source, then in theory the speaker isn't doing it's intended job. Do you really believe you can justify a speakers inability to reproduce sounds accurately by stating that some listeners prefer a speaker that has aggresive mids or a more punchy bass. It implies that perhaps polk is more interested in market trends then the accuracy of sound reproduction. One difficulty with building speakers is what humans hear vs. what we want or think we are hearing. It's all too subjective. Our brains are simply not set up to interpret audio information. In the animal world we are one of the worst as far as hearing performance.
well, in theory its impossible to reproduce sounds the exact same as the original source, ESPECIALLY in a car
too many factors contribute to taking noise away or adding noise
and some people do like more agressive meds or more punchy bass...why do you think bandpass was invented....you think they want the bass exactly the way the its sposed to be...or just loud bass
different types of tweeters contribute to this also
cone..dome...balanced...horn compression all sound different but each have their own specific purposes
while yes...i want my speakers to duplicate the exact same sound...no i dont want to spend the thousands of dollars to do that...therefore we have midline speakers like polk audio that do a job good enough for a price that just about anyone will enjoy
-Cody

[PoweredByDodge]

if a speaker duplicated a sound perfectly, then 3/4 of the music i listen to now... i wouldn't listen to.

i'd find it annoying and unenjoyable to listen to.

each listener has "Desires" for their audio system... and each ear is a little more sensitive to one range of audio or another...

however, it is very common for the "mid" to be lacking in most car speakers... leaves u with a boomy / tinny sound that sounds cheap as hell.

polk has, for a while now, done a very good job of building speakers which cover that 500 to 1,500 hertz range better than any other company i've listened to yet.

speakers are like art.

u dont just connect the dots for an exact reproduction, you design -- emphasis on design -- a speaker that'll dance and sing for you the way that yourself (the designer) and the majority of your customers will truly enjoy.

while i think the EXII are a little too goddamn harsh and go to hell on high power... they're still a good speaker... the EXIII's ive got now put the EXII to utter shame, and for sound quality on lower (under say 75 or so watts) power match my DX's pretty well (which is saying a lot)... over that -- the DX just can take more of a beating and thus has served me well in that regard...

music is meant to be shaped to the vehicle... and while you can do a lot with processing you still need speakers that will help a bit too.

["Polk" Paul DiComo]

My last post before I go away for 2 weeks...

Yes the theoretical goal is perfect recreation of the original performance. Not possible at this point in time. I have heard $100,000+ audio systems that sorta came close...but not quite. No car stereo even remotely approaches the standard that sirogenous aspires to. But that doesn't mean that we (manufacturers and listeners) should not try to get as close as possible. If we (Polk Audio) were simply interested in "market trends then the accuracy of sound reproduction" one of the last things we would do is smooth out the midrange (look again at my listening notes at the beginning of this post). An inexperienced listener will hear a speaker with "projected" midrange as being louder and "clearer." Frankly there are more inexperienced listeners buying car stereo than experienced listeners. That puts our stuff at a disadvantage in sales appeal. We are betting that there are enough people who will listen a little longer and discover that flatter (more accurate and closer to sirogenous' ideal) midrange is better. Hope we are right.

But guys, let's remember that listening to music is supposed to be FUN, especially in the car. So I say if you have more fun listening to a bandpass box booming away in the hatchback and horn tweets screeching up front - more power to ya. Go for what makes your ears happy. If that is Polk, cool. If not, well we never thought we could win them all. Just have fun.

[Jstas]

I got a chance to hear the DB 6x8's today. I gotta ask a question, how easy would it be to put that 1 inch tweeter in them? I heard a definte difference.

They are a very, very nice speaker for 100 bucks a pair though! They blow the EX series out of the water IMO. They have good low end response, which is what the EX series lacked. That was my only gripe about the EX series.

But, eventhough they have good low end response (being run on 50 watts RMS too) the highs seem kind of dead. Maybe it's because I'm used to the crystal clear highs of my dB speakers in my truck, I don't know. So I was wondering, how easy would it be to stick a 1 inch dome tweeter on those speakers? That would probably be the best improvement to make. Especially if you can keep the price around 100-120 dollars a pair. They are a more than adequate replecement for the EX series and are light years ahead of the GNX and GXR series.

Since they aren't really meant as the top of the line like the old dB, I can't really compare them. But, I think that bigger tweeter would make the best improvement and give you a mid-line speaker that would just thrash EVERYTHING else in it's price range.

They had excellent, accurate mid-range. Nice and smooth with a flat response. Good low-end kick but not like a large woofer or sub-woofer. A system put together with DB speakers would defintly need a sub to reach the real low end consistiently and accurately. Overall though, they are definitly worthy of the Polk reputation and I think I am going to deck out a Harley Davidson F-150 with them. Great performance for it's price point. Still not a dB by the standards set by the originals but defintely worthy of a Polk Audio badge. I think I'd want a more heavy duty test then what the guy who had them put them through but from what I could tell, he was not pushing them as hard as they could take.

[sirogenous]

Do I smell a reference to the ol' Klipsch horn speakers? And I thought my RTA12's were dinosaurs. I thought about squeezing them between the dashboard and the front windshield of my truck. But I would have to sit in the middle of the seat while driving or I'd lose all sense of soundstaging. Not too mention they'd make driving a little harder to do. lol :p