| sjetski71 |
Hi all, first time poster in this great subforum, have lurked plenty though.
Long story short: I recently picked up a sony SA-WM250 8" vented sub, which is rated 100 watts @ 6 ohms 28hz~khz?. Picked up it for a secondary theatre in my home just to add a few lows to the current bookshelves i have there. It was sort of an impulse buy since i picked it up on clearance for reeal cheap, but anyway. It did get mostly 5 star ratings at all the rating sites if that means anything.
I have not even hooked it up yet but i got to thinking, would i perceive a big difference in sound quality if i were to swap out the driver for something better? If the answer is yes, is there anything i should be aware of? (that oddball 6 ohm rating for example) Or are there certain drivers i should stay away from? Would a high Xmax rating really help with this sub? I wouldn't want to sink much more than $30 to $40 into this swap since that money would have been better spent on a different sub altogether ;).
I had bookmarked these 8" subs but held off buying till i could get definite answers to the above questions. I have tried researching for a few days but feel like i'm still at square one :xeye:
- Dayton 8" classic $20: http://www.partsexpress.com/pe/show...tnumber=295-310
- Dayton 8" DVC $23: http://www.partsexpress.com/pe/show...tnumber=295-480
- Pioneer B20FU20-51D 6 ohm $23: http://www.partsexpress.com/pe/show...tnumber=290-055
- Audax Aerogel 6 ohm $37: http://www.partsexpress.com/pe/show...tnumber=296-175
- Dayton 8" reference series 4 ohm or 8 ohm models ($43)
- The Apex Jr Super 8" perhaps? http://www.apexjr.com/SuperSub.htm
- This 8" Vifa sub for $23 shipped: http://cgi.ebay.com/OEM-8-DIY-DUAL-...1QQcmdZViewItem
- I can pick up two Velodyne VLR series 8" subs for $40 AC @ Overstock.com. This would leave me with an extra 8" woofer for a 'possible' future project with this Infinity three-way amp.
Many thanks in advance for any insight or recommendations. |
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| badman |
| A more viable approach would be to add a layer of plywood to the outside of the sub- a stiffer enclosure makes a world of difference. Most subs at the bargain price range employ electronic EQ, so swapping out the driver requires testing, either of the driver, or of the amplifier's transfer function. |
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| sjetski71 |
Interesting, hmm.
Would adding braces inside the enclosure bring any sort of benefit do you think? I ask because it would be a lot less work than adding plywood to the exterior then finishing it off to something visually presentable. I could also add a bit more foam-filler to the interior while i was in there, and perhaps some bonding substance to all the wood joints (?) I just might try the plywood idea though, especially if i can get my hands on some nicer slabs.
I take it that swapping drivers is too hit or miss to recommend? I'm still mulling the idea, and am hoping to stumble upon more information.
Thank you for the info |
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| nunayafb |
Aside from the important issues mentioned by badman, you also have one huge challenge to overcome. That box was designed for that woofer, hopefully. To see if any of those speakers are compatible you need to download winisd(pro) and model them in the box volume that you have, changing the tuning until the required port length matches the port you have now. If you are willing to by another port then all you need to do is be careful that the length required will fit in the box.
For volume calculation, make sure you factor in port volume and the volume occupied by the speaker basket.
Make sure you can purchase a port that will fit into the box! Sony is notorius for proprietary parts that are only manufactured for sony by sony. Or be prepared to upsize the port hole or glue a loose port in.
On a different note, why do you want to replace the woofer you have?
You need to listen to it so you can put into words what specifically you want to enhance. There are too many conflicting properties with woofers that you need to be careful of:
-high excursion woofers tend to have lower efficiency
-high efficiency woofers usually have lower excursion and therefore reduced low bass output
-cheap and small does not go well with low distortion and high output
Anyways, if the sub sounds ok or better I would advise leaving it alone. If this is for learning then by all means download the software and start modeling the woofers you linked.
Some keywords you might want to read up on:
sealed vs ported, Group delay, plate amps, efficiency, port resonance build up(ramp up?)-this will cause problems mostly with sustained bass notes-,f3,fs, Qts,Vas,rms/peak power, and many more. If you get a good understanding of all of those terms and read several articles on each you wont even need to ask whether or not you should do this project, you'll understand why. |
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| sjetski71 |
It is as i suspected. There is much calculation that needs to be done before someone undertakes what i have proposed.
With my research i had finally begun to understand that building subwoofers could be complicated, you fellas have confirmed it. I 'may' proceed with the minor enclosure modifications but will save the complicated aspects for a possible future diy sub (i like those sonotubes!) :)
Thanks again to the both of you |
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| sYkboy |
| I say just use it as is for awhile. If anything, first spend a good amount of time auditioning for where it needs to go. Placement might help. As for drivers, you may be able to find one to work well in you cabinet but then you are almost at the price of just buying a plate amp and sub and putting it in the proper enclosure. |
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| dangus |
| The best bang for the buck could be to just buy another one of those subs if the sale is still on. Two subs will play louder than one, and by planting the subs in different locations the room response will be more even than from a single sub. |
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| auplater |
| quote: | Originally posted by dangus
The best bang for the buck could be to just buy another one of those subs if the sale is still on. Two subs will play louder than one, and by planting the subs in different locations the room response will be more even than from a single sub. |
this is dead on great advice... you'll get much more "bang for the buck" by experimenting with room placement than trying to upgrade... try "NOT" placing the 2 woofers in corrners... maybe along the sidewalls, play with the phase (reverse leads to one sub)... check out your listening position, that sort of thing...
adding a second sub makes a world of difference...
auplater |
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| sjetski71 |
| quote: | Originally posted by dangus
The best bang for the buck could be to just buy another one of those subs if the sale is still on. Two subs will play louder than one, and by planting the subs in different locations the room response will be more even than from a single sub. |
hmm, oddly i hadn't thought of that, it's something i'm going to have to consider. Now hopefully i can still find more where i had bought it ($50 + tax). If it is sold out then i could just plant that same money into a small 10" or 12" sonosub project. I used to help my buddy build car sub enclosures when we were kids, i remember it being a lot of fun too. I really enjoy the research stage so maybe i should be planning my fall/winter project now :) |
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| Bogie |
| MCM has a dandy little 8" driver that goes VERY nicely into one of Bill Fitzmaurice's tiny horns... |
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| auplater |
| quote: | Originally posted by Bogie
MCM has a dandy little 8" driver that goes VERY nicely into one of Bill Fitzmaurice's tiny horns... |
Horn? what does a horn have to do with this thread?
This is about SUB-WOOFERS... not honky-horny thingies...
looks like a mis-post to me |
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| auplater |
been there...this is nothing amazing... lotsa hype... didn't like the horn sound... I've built horns way back when... lots of efficient output, not such good low end quality... great if you're into that sort of thing... not for me...
no hoof in mouth disease here... maybe at your end? |
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| nunayafb |
| Sorry bogie, I gotta agree with auplatter on this. The auto tuba rolls off at about 8.5dB/oct from 80hz down to 20hz in cab, so in a large room that thing will be a very loud woofer with no low end. notice how flat that sealed sub is, the sensitivity might be lower but with the power handling of todays drivers flat response wins. |
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| john65b |
I think I have that same sub...I also got it dirt cheap brand new (under $65). Anyway, I found a site that details a few sub mods - one of which
is stiffening the cone by coating the outside and inside of the cone with Modge Podge (kinda like elmers glue - smells like it too) - you can get it at any craft store...next was put in some Egg Crate Foam on the inside...I did a few other things too, but don't remember. These were the two biggies.
Anyway, sounded a lot better - tighter - but it was never that bad to start with, just a lttle loose...I would not replace the driver....if you really want to build one, build a passive out of a sonotube... |
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| sjetski71 |
| quote: | Originally posted by john65b
I think I have that same sub...I also got it dirt cheap brand new (under $65). Anyway, I found a site that details a few sub mods - one of which
is stiffening the cone by coating the outside and inside of the cone with Modge Podge (kinda like elmers glue - smells like it too) - you can get it at any craft store...next was put in some Egg Crate Foam on the inside...I did a few other things too, but don't remember. These were the two biggies.
Anyway, sounded a lot better - tighter - but it was never that bad to start with, just a lttle loose...I would not replace the driver....if you really want to build one, build a passive out of a sonotube... |
Each of those ideas is very interesting, and thanks for sharing this very related info, being that you have the same sub and all.
I'm more than comfortable searching but do you happen to have a link to the sub mods you mentioned? I wonder if fiberglass would make a better filler than egg crate (?) since i have a few different types packed away somewhere. I will use the sub as-is for awhile to get used to it's characteristics, then when i yearn for something better then perhaps i'll begin the modifications :). But yea, otherwise the sonosub is def a major candidate for a fall/winter project.
john65b: I've subscribed to that motorola DCP501 thread btw. You guys are really tempting me with that amp! |
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| badman |
| quote: | [i]
john65b: I've subscribed to that motorola DCP501 thread btw. You guys are really tempting me with that amp! [/B] |
Buy now for the good price |
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| john65b |
Ha! Small Forum, huh?
I have three DCP-501's, ordered (15) 2.2uF polypropylene input caps, have (15) 20K SMD resistors for the overload mod/fix, a number o extra 75V 10,000uf caps for the power supply, but can't find my soldering iron cause my basement is still getting finished!
Can't wait to dig into it.
Dude, buy it...power beyond your needs after you brdge four of the five channels. Cripes, 300 plus wpc of tripath power for $69? Unreal. I want to know where this guy gets them from so cheap... |
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| sjetski71 |
| quote: | Originally posted by badman
Buy now for the good price |
Ya, noticed the big price drop around a month or so ago. Needed different features for HT unfortunately though.
| quote: | Originally posted by john65b
Dude, buy it...power beyond your needs after you brdge four of the five channels. Cripes, 300 plus wpc of tripath power for $69? Unreal. I want to know where this guy gets them from so cheap... |
Pretty sure he had over a thousand of them originally, Thought he bought them direct liquidation(?) Unfortunately i've already picked up a HT receiver with the features i need, and already have two T-amps that are begging for a bi-amp setup. Spreads the project money awefully thin ;) |
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| sjetski71 |
| quote: | Originally posted by Bogie
MCM has a dandy little 8" driver that goes VERY nicely into one of Bill Fitzmaurice's tiny horns... |
Finally got around to researching your suggestion, and found that highly tempting driver you were speaking of...the MCM 55-2421 which goes for a paltry $31. Can someone please give me a reason not to buy this driver? From the research i've done on it so far it seems to do well in small ported enclosures, and it definitely has great specs for a small driver. I would try modeling it with winisd pro first of course, which i may download tonight.
I have been using the sony sub as-is btw, but have recently applied modge-podge to the outside of the cone, which has produced an audible difference. Next comes some box bracing, some poly-fill or fiberglass filler and modge-podge to the inside of the cone. I guess i ought to await the results of those mods before even considering buying that MCM driver.
On a side note, i'm nearly positive that i'm going to build a smaller 10" diy sub this fall/winter and almost pulled the trigger on an amp and driver, but first i'd like to hear the results of this sony venture :). |
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| kevyjo |
| I would encourage the DIY project, any expirience you have with the Sony might make it easier, but I think a DIY sub is a pretty forgiving project for the bigginner, it sounds like your ready, and you have the sony in the mean time |
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| sjetski71 |
| quote: | Originally posted by kevyjo
I would encourage the DIY project, any expirience you have with the Sony might make it easier, but I think a DIY sub is a pretty forgiving project for the bigginner, it sounds like your ready, and you have the sony in the mean time |
Slight change in schedule, but thx for the vote of confidence :)
Just recently picked up a new proficient S10 10" subwoofer (pre-built) for a song ($98 shipped) which effectively delays my DIY plans by at least a month or two. This is not necessarily a bad thing since it gives me time to research and mull over different ideas.
Have also begun to consider a tall thinner sonosub, something between 4' to 7' tall and narrow enough to just accomodate a decent 10" driver. Hoping it can drop down to 24-27hz but we'll have to see i guess. I understand that i may have to scope the smaller sonotubes or even PVC perhaps. But i like the idea of a thinner "bass column". If i do pursue this, and it turns out well, then i'll leave the door open for a second one. Anyone ever hear or see such an idea implemented before? Depending on my overall budget i would either use this infinity amp, or just "splurge" on a behringer A500. Wish that infinity amp had mono inputs but i guess i can work around the high-level inputs somehow.
The research and planning stage is half the fun in my opinion :)
Thanks again to everyone for your help and ideas. |
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| kevyjo |
| of course if you own a house and want to get kinda crazy you could do an "Infinate Baffle" sub |
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| sjetski71 |
In case anyone was curious, i completed the mods to the sony sub.
I braced the insides of the sony cabinet vertically and horizontally. Coated both sides of the paper cone with modge-podge crafts glue. Lined the inside walls with a peculiar, thin yet dense foam-type carpet pad underlay. I've seen nearly all types of carpet padding before and i can truly say this is composed of a formula that i'm unfamiliar with. Well i lined most of the cabinet walls with the stuff and left plenty of clearance by the port area. The cabinet seems extremely sturdy btw, it is at least 3/4 mdf and the front baffle area may be thicker but i didn't measure it so i can't be sure. The woofer looks sorta cheap but it had some weight to it, maybe because of the ferrite bucking magnet glued to the back...
The results you ask? Well it sounds like a totally different sub beyond any doubt. It now sounds much more like the Proficient S10 sub i bought, and more closely resembles the Bic H100 in my main theatre area. What i mean is that the bass sounds more controlled somehow, it recovers from the "boom" sounds faster. I think i can hear individual bass notes more clearly but i need to give it some critical listening to be sure.
Am i satisfied? Of course not ;), this small endeavor has piqued my cusiosity with better quality bass. I'm still likely to swap the sony 8" driver with that MCM 55-2421 i mentioned prior. I also want to scope the insides of this Proficient sub i bought, and perhaps brace and line the insides of it as well.
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Still interested in researching and possibly building that thinner/smaller sonosub. Out of curiosity, does anyone think i can drop in a quality 10" or 12" driver into a 12" x 48" ported sonotube and still have it reach down to 20-24hz ? Or is that just a pipedream for such a small piece of sonotube?
Thanks again for reading and for all the assistance.
- Steve |
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