Picked up a MTX RFL152, pics!

[SPLaudio 5,000+ posts]

i dont have a cone that will work on that basket sorry. i can build wth a different basket though.

only way those subs were loud was cutting 2 of the 4 spiders out every competior did that with those back in the day.

that is a 4 layer round wire coil...

 

[Wingman0121 10+ year member]

Is the gap big enough for an 8-layer coil? Seems pretty tight.

I don"t particularly care about the basket since it's such an odd size, what kind of sub can you build from this motor? A 15 or 18? A 10 inch fat bastard?

 

[Liquid Bass 10+ year member]

It may not need a recone man. If it's anything like my hcca the coil is most likely rubbing because the previous owner took the cone out and didn't get it aligned. I had a hell of a time getting my hcca aligned after I took the cone out

 

[DonH 5,000+ posts]

yaaaay one note wonder! never been a fan of how the woofer sounded....

 

[nateberrier 10+ year member]

Not sposed to listen to spl moofers brah. also fyi my treo csx is 874oz with a 3 inch coil 0_o. A guy at a meca comp was talking about these and how he missed them one day lol. I got really excited to see this

 

[teamquakecelica 10+ year member]

good luck with that motor...

A little insight:

-the magnetic gap on that motor is TINY.. once reconed you wount get more than 15mm xMAx

-for all that steel and ferite.. its a pretty weak motor.. decent BL in the gap.. and TERRIBLE out of the gap

-because its an "SPL" motor there is no copper in the motor... so stray/eddy currents run RAMPANT

-I understand that all companies have diffrent ideas on how to build an "SPL" sub... and this was MTX's attempt.... and it was OK.. for SPL.. nothing special at all... but it was sort of..kinda useable.. trying to convert it to a DD sub.. IMO is like trying to convert an Indy car to a station wagon... yeah it can be done... but why take the time.. go get something that is made for the purpose you want to use it for..

Ryan

 

[nateberrier 10+ year member]

I say build it into something that plays and sell it

 

[Suicide Bobb 5,000+ posts]

I say keep the dustcap, get an exact recone built with the same inverted surround, and plop the dustcap on the new recone. I hate when people take unique subs like this and throw weird recones on them that make them look nothing like the original. Ruins the point. 99% of the reason you would own one of these is for how they look!

 

[jco1385 5,000+ posts]

there are 2 of these local for $300... hmmm. i remember when they came out and were in crutchfield mag. i was droolin over them when i was like 14. lol

 

[SPLaudio 5,000+ posts]

the coil is shot look at the windings with the gaps.

no its not the be all end all motor by any means but decent.

nate that oz is total motor weight not the weight of just the slugs.

 

[Wingman0121 10+ year member]

good luck with that motor...A little insight:

-the magnetic gap on that motor is TINY.. once reconed you wount get more than 15mm xMAx

-for all that steel and ferite.. its a pretty weak motor.. decent BL in the gap.. and TERRIBLE out of the gap

-because its an "SPL" motor there is no copper in the motor... so stray/eddy currents run RAMPANT

-I understand that all companies have diffrent ideas on how to build an "SPL" sub... and this was MTX's attempt.... and it was OK.. for SPL.. nothing special at all... but it was sort of..kinda useable.. trying to convert it to a DD sub.. IMO is like trying to convert an Indy car to a station wagon... yeah it can be done... but why take the time.. go get something that is made for the purpose you want to use it for..

Ryan

Can you tell me the BL on the RFL? I had two 3hp Eclipse SW9122 motors before and those are smaller in size and weight but of course they're very different. Now if people can build good-sounding subs from team RF motor, the original Cerwin Vega Stroker, various DD motors and that mad max motor from that custom pink cone sub then why can't this do it? Even with different soft parts/cone and maybe even a new top plate if that's possible? I know the 4.35" excursion is a lie because the suspension on this sub won't even allow it to move that far, it looks like this particular sub spent most of its time within 2" of movement.

Wanna chime in on this SPLaudio? Can this be turned into something cool? I know Team PSI did a few but I donno what they say about it.

 

[FtheNutHuggers]

ok, simple: have a machine shop make you a "top plate extension". You know your top plate ID, you know your basket mounting flange ID.....make the plate extension out of 18mm low carbon steel with the same ID as your motor's top plate and OD about 2-3mm shy of the basket mounting flange ID. That leaves a little play room for the basket to mount around it. That plate will need the same primer and glue used on most motors. Now your coil center will be higher than before as your gap will be taller, but the bottom of the gap still remains at the same height from the top of your back plate. You can effectively use an 18mm taller coil and still have the same rearward stroke capability. Your coil ww center will sit 9mm higher and your coil would be overall 18mm taller than the previous coil. same rearward clearance. This would allow you to use larger gauge flat wound wire to achieve your desired final DCR with coils wired in series.

another way to change it up would be to slowly screw in bolts that are longer than the top plate is thick. make sure you put cardboard around the pole piece to be able to remove the top plate from the motor as soon as it shifts. take that to your machine shop and have them bore the ID out to whatever you choose, so long as it is smaller than the ID of your magnets. this allows you to use a pair of coils with more winding layers. Either way, make sure you get a pair of coils that are bifilar wound. Do the same thing with the top plate extension ring to make it mate up to the top plate. now that both pieces are off the motor, you can have your machine shop attach copper or aluminum shorting rings below and above the top plate assembly. ask your new cone/surround provider how many different surround options you have as far as compliance goes. it's way better to build up your compliance with surround foam thickness than to stack a number of spiders together. Let the spider do what it does best; keep the coil centered. this way you also have a relatively broken-in subwoofer after just a few minutes of high excursion use and your surround will basically remain the same throughout the life of the subwoofer. play it without a dustcap first to see if your need to add any mass around the former, above the cone joint. if so, add.....if not, glue the dust cap on and have a fun summer.

 

[Suicide Bobb 5,000+ posts]

ok, simple: have a machine shop make you a "top plate extension". You know your top plate ID, you know your basket mounting flange ID.....make the plate extension out of 18mm low carbon steel with the same ID as your motor's top plate and OD about 2-3mm shy of the basket mounting flange ID. That leaves a little play room for the basket to mount around it. That plate will need the same primer and glue used on most motors. Now your coil center will be higher than before as your gap will be taller, but the bottom of the gap still remains at the same height from the top of your back plate. You can effectively use an 18mm taller coil and still have the same rearward stroke capability. Your coil ww center will sit 9mm higher and your coil would be overall 18mm taller than the previous coil. same rearward clearance. This would allow you to use larger gauge flat wound wire to achieve your desired final DCR with coils wired in series.
another way to change it up would be to slowly screw in bolts that are longer than the top plate is thick. make sure you put cardboard around the pole piece to be able to remove the top plate from the motor as soon as it shifts. take that to your machine shop and have them bore the ID out to whatever you choose, so long as it is smaller than the ID of your magnets. this allows you to use a pair of coils with more winding layers. Either way, make sure you get a pair of coils that are bifilar wound. Do the same thing with the top plate extension ring to make it mate up to the top plate. now that both pieces are off the motor, you can have your machine shop attach copper or aluminum shorting rings below and above the top plate assembly. ask your new cone/surround provider how many different surround options you have as far as compliance goes. it's way better to build up your compliance with surround foam thickness than to stack a number of spiders together. Let the spider do what it does best; keep the coil centered. this way you also have a relatively broken-in subwoofer after just a few minutes of high excursion use and your surround will basically remain the same throughout the life of the subwoofer. play it without a dustcap first to see if your need to add any mass around the former, above the cone joint. if so, add.....if not, glue the dust cap on and have a fun summer.

I didn't understand a word you just said. Try speaking American, it's the only language I understand.

 

[teamquakecelica 10+ year member]

Can you tell me the BL on the RFL? I had two 3hp Eclipse SW9122 motors before and those are smaller in size and weight but of course they're very different. Now if people can build good-sounding subs from team RF motor, the original Cerwin Vega Stroker, various DD motors and that mad max motor from that custom pink cone sub then why can't this do it? Even with different soft parts/cone and maybe even a new top plate if that's possible? I know the 4.35" excursion is a lie because the suspension on this sub won't even allow it to move that far, it looks like this particular sub spent most of its time within 2" of movement.

Wanna chime in on this SPLaudio? Can this be turned into something cool? I know Team PSI did a few but I donno what they say about it.

I havnt heard any of those "franken woofers" you mentioned.. I have serious doubts than a reconed stroker or DD would sound "good" to me... now everyone has different ears... and if you or others like those subs.. then thats all that matters.. but I"m sure they are FAR from actually sounding "good" from a manufacturer standpoint.. you wouldnt sit one of those next to an Aura Neo and say.. "wow I like that reconed half assed stroker better"... unless you are Hellen Keller.. well you would say "GDRHFPFFFF" if you were Helen Keller.. but I digress..

a 3HP motor is VERY different than an RFL motor.. close to the same size.. yes.. same parameters??.. no where near close... the 3HP has some sound engineering and manufacturing behind it.. the end all-be-all?.. nope.. but a GREAT general purpose motor that you can rely on consistently...

A 4hp motor is another different animal.. I have NEVER heard a 4hp that I like.. they sound very punch and hollow to me.. but its all preference.. if you like.. own it... if you hate it.. sell it to someone that does liike it //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I believe the BL on the RFL was arnd 22tm.. lower than a 3hp which is in the 27tm range

 

[Haunz 10+ year member]

A little insight:

-the magnetic gap on that motor is TINY.. once reconed you wount get more than 15mm xMAx

-for all that steel and ferite.. its a pretty weak motor.. decent BL in the gap.. and TERRIBLE out of the gap

-because its an "SPL" motor there is no copper in the motor... so stray/eddy currents run RAMPANT

A thin topplate will give more xmax then a thick topplate given the same size coil, but you will get less BL. Also the vast majority of subwoofers out there do not use faraday rings. They do improve distortion figures, but its not like the motor will be no good because it dosen't have them.

OP the right spider and coil configuration should make that sub into a great daily pounder...