Sony Speaker Overhaul with Polk Drivers.

LiquidSound · June 2003

Here's the situation, I've got a sony HTIB that belongs to my girlfriend. As a present to her *and myself* I want to overhaul the sony's with Polk drivers..preferrably. All new parts and even a new paint job and grill cloth replacement. Sounds like a lot of work I know..but it's for my girl *and did I mention me* That, and I've got an urge to start a new project. The system is about six years old she says. It's the SLV-AV100 reciever/vcr combo. I think it puts out about 60 watts..I can check. I wanna revamp the speaks and then get a new reciever when I have more cash. I've got measurements of the speaks, pictures and model numbers as well..but i'm on lunch and don't have time to post them just yet. Do you guys think it would be a worthwhile venture?? Remember, it's not about the effort.
Thanks in advance fellas.

hoosier21 · June 2003

I am assuming the following: you are just wanting to replace the el cheapo driver in the Sony speakers with something "better". And you are not going to worried about crossover design modifications and such.

If this is the case, go to partsexpress.com and get some good quality drivers there for alot cheaper than replacement drivers Polk offers.

RuSsMaN · June 2003

Yeah, what Hoosier said.

BeginnersLuck · June 2003

Yeah, what RuSsMaN said hoosier21 said...sorry just had to do it...

VR3 · June 2003

Yeah, What beginnersluck said about what Russman said about what Hoosier21 said about what Liquidsound wanted to know. Wow, that was cool. Get some Bose fullrangers...............

LiquidSound · June 2003

Would it not be worth the cost? I'm seeing this as a learning experience so the effort is no problem. Not to mention, if I don't change something..I'll have this gorgeous piece of work in my speaker

RuSsMaN · June 2003

Nice terminal cup. I'd look at in-expensive replacement drivers, and experiment with simple first-order networks.

Whats the driver compliment in these speakers now?

LiquidSound · June 2003

My other beef is that I'll only have a 2 way for a center speaker. I'd like to at least have a 2 way that would match the tweets in the mains..if not try to modify and add a tweet. But positioning is a **** in the scenario.

RuSsMaN · June 2003

Just mount the tweet to either size of the midbass, or do a 'free air' mount on top.

Are all the speakers simple, full-range, single driver designs? What size driver is that?

LiquidSound · June 2003

By driver compliment I'm assuming you mean what do I have in them..and simple first-order networks, crossovers yes? Sorry...speak slowly with this one.:D I need a speaker building manual to gain insight into the fundamentals of speakerworks. Is the Loudspeaker Design Cookbook a good choice? Here's the main.

LiquidSound · June 2003

The center and surround drivers are the same size, but the center has a bigger magnet and such. Both measuring 5 5/16 from tip to tip of the mounting plate. The main driver is 6 5/8 and the tweet is 3 7/8..both from tip to tip.

hotwheelman · June 2003

Nice bowl there man.:D Do get some drivers from parts express or mcm electronics, you will be glad you did.

RuSsMaN · June 2003

Those certainly look workable.

1st order - 6db/oct slope
2nd order - 12db/oct slope
3rd - 18
4th - 24

A simple 1st order network will consist of at 1 capacitor on the postive wire of the tweeter, to pass signals greater than xxxxHz. Choosing the cap will depend on the desired 'high pass' point, and the impedance of the tweeter.

Staying 'simple 1st order' as above, you can let the woofer run 'full range', out to its upper -3db downpoint (lets say 4000Hz for example), and I would put a cap on the tweeter to pass it at about 1/2 octave lower, say 3000-3500.

If you want to do a little more, but stay first order, you can add a 'choke coil' on the woofer, to pass signals less than xxxxHz (just as you would do on the tweeter above).

Vance Dickanson's cookbook is a GREAT book. However, hang out around the partsexpress forum, just read for a bit.

First step, measure the internal cab dimensions, and start shopping for a mid-bass.

Cheers,
Russ

LiquidSound · June 2003

That's the "Potato Soup" modification. Polk customer service told me about it. Better yet, check my crazy nice speaker stands. Aren't you envious.....

LiquidSound · June 2003

Am I measuring for how deep the driver can go into the cabinet?

dthomps · June 2003

Maybe I am way out of place here since I hardly understand most of the stuff Russ was spoutin' above, but you might also want to find out what impedance those speakers are.
I am pretty sure with my buddies "DREAM" system the speakers are all 3 ohms.
Just something to consider.
Looks like a really fun project.
Mike

LiquidSound · June 2003

The back of the speaks say precisely ZIP about ohms. It only gives a model number and either mayalasia or taiwan.
It should be quite a fun project. I'm not telling my girl anything about my project. I'm just going to bring her in blindfolded, let her hear the new quality and surprise her that it's her speakers making that sound. I can't wait.

by the way, this is an older system of maybe six years..and hardly a dream..heh.

RuSsMaN · June 2003

It really doesn't matter what's in the cab now, I'm going to assume probably 8 ohm drivers for a Sony rig like that.

Remove a driver, measure the 'cutout' size. Let's find a driver at LEAST that size or larger, so we don't need to fab new baffles.

There are a LOT of ohm combos we can rig in a 2-way design, don't sweat that now, whatever you get, we'll get you back to 6-8ohm total for the speaker. Start browsing for drivers in your price range.

Cheers,
Russ

LiquidSound · June 2003

The center and sat cutouts are 4 1/2in. The mains are 5 3/4 and 2 1/4. What determines the price of the drivers is the cost of the crossovers and terminal cups..which I think I need new cups at least on the mains. The others don't look so bad. Not sure of their quality though.

By the way, do you think I could put two tweeters in the center and not have any troubles? I'm all about some symmetry..that aside, would it have any benefit? Disadvantages besides cost and extra work?

I really appreciate the help...

hotwheelman · June 2003

Internal cabinet volume needs to come into play here as well, just picking a driver and placing it in there won't always yield the best result. There is a section in the loudspeaker cookbook( can't seem to find mine right now) that will tell you what you need to do to figure internal cabinet volume, from there you will use that calculation along with the fs, qts, and vas. to see which driver will work best for you. I built a pair using mcm drivers and crossover, and a pair of blank baby advent cabinets that I had purchased from parts express. Those were the best sounding little speaks until they were ripped off of me from someone that I thought I could trust, wish I had those back as they would have made decent surrounds for my h.t.:rolleyes:

Mike

LiquidSound · June 2003

Outer dimensions are as follows: Center 15 1/8W - 5 15/16H - 4 25/32D with a 1/4in. recess in the back panel

Surrounds 6 7/8W - 5 7/8H - 4 7/8D with a 1/4in recess in the back panel

Mains 7 31/32W - 16 7/8T - 9 1/8D with the front and back recessed slightly totalling 2/16in.

They're all made with ultra high quality 1/2in. plywood..heh.

LiquidSound · June 2003

Instead of replacing the drivers first, I decided to upgrade the wires first. I had several of the drivers taken out of the cabinets while checking the build quality and upon putting them back in and checking to see if they worked, I heard pure sonic trash coming from the tweeters. So I went from silly little/super skinny stock wires that came with the HTIB to Monster XP Cable and heard an entirely new depth of quality coming from the sony's. I, and my girlfriend were both rather impressed with hearing new subtleties and understanding more lyrics from the music that we can mutually enjoy.*which isn't a whole lot*

Then I added a PSW202..which added a whole new take on the situation. With my limited experience with the 202, I can say it's boomy but damn powerful. Only playing the lowest of lows and accentuating them quite a bit. But this is with very short times of break in and considering the fact you get what you pay for. *189 @ CC* not to mention this is the first actual subwoofer I've ever owned. I plan on upgrading to the 303 ASAP.

My next venture is building some nifty little speaker stands modelled much like the ones that tryrrthg built.

I'll save the drivers for last, after I've scored a copy of The Loudspeaker Cookbook and done my homework in figuring out the best drivers/possible porting for my cabinet sizes.

An interesting project it shall be.

LiquidSound · June 2003

Perhaps I should say I'm upgrading to a low level Denon or Onkyo 5.1 reciever last. That should give the system a nice kick in the ****.

burdette · June 2003

The Loudspeaker Design Cookbook or any other resource isn't going to help you much on this ... unless you have better luck than I did... because you aren't going to get the T/S parameters for any Polk drivers from Polk. And without those, the best you can do is try to match a cabinet and port combination from an actual Polk speaker. And, bottom line, if you don't have Polk's design for or actual crossover, you are *not* going to recreate the sound.

Edit: To answer your question.. no, the Loudspeaker Design Cookbook isn't the best book to start with.. from what you've said you aint' spillin' over with design experience. TLDC is.. oh... second or third tier and assumes you have some knowledge. Yes, it goes over the fundamentals, but in pretty technical prose.

Appears you have maybe half a cubic foot volume in the mains, less than 1/10 ft3 in the surrounds, and about 3/10 ft3 in the center. The surround and center are dang small... I don't know of any Polk drivers other than the HTIB ones that might work in volumes that small. The R10 and R15 are small....

Edit: no, the crossover and the terminal cup do not dictate the cost of the drivers. You select the quality of drivers you want to use and then select crossover components to match.

You ask whether this is a worthwhile venture.. and state that it is NOT about the effort. I assume it is about the ultimate result then, regardless of work involved? To answer your question.. no, I don't think this is worth the effort. ANY redesign begins with SOME component of the original that you want to or must maintain. In your case, you want to use the old cabinets and replace drivers. I don't think the old cabinets are worth, are the right size for, or are up to the challenge of what you want to do.

I agree the effort would be fun and interesting... but having designed speakers from the ground up, and having recreated Polk speakers using old components...

Honestly, I think you'd have MUCH better results and improve performance if you chose to use nonPolk drivers from someplace like Parts Express or Madisound.

Here is the page for a 2-way using a 5.25" woofer in a .. wouldn't ya know it... 0.48ft3 box.. right on the money for your main cabinets. The drivers used are VERY well thought of, and I think we could get a design for the center and surrounds as well.

http://www.speakerbuilder.net/web_files/Projects/DBP/dbp.htm

Here also is a project suitable for your main box. Uses a 6.5" woofer, so perhaps less baffle mods.

http://www.speakerbuilder.net/web_files/Projects/D2/d2main.htm

LiquidSound · July 2003

First of all, thanks burdette and all who have helped me on this venture.

Soon I realized that I shouldn't try using polk drivers in the sony's..which burdette's post reiterates. I tried to change the title of the thread but only succeded in changing the subject of the first post.

Anyway, I've decided to remove the weakest speakers in the setup, the center and surrounds, and replace them with Diy jobs. Upon completion I'll move the mains to the surround spots.

Since I'm unsure if I'd like the sound of the diy, I'll just replace the worst speaker first *the center* with this. As far as the drivers go, I'm still up for opinions. Budget on the drivers is about 60 per speaker..I'd like to not spend that much but if it's going to take a large dip in SQ then oh well. If I like the sound of the center, I'll get two more and replace the mains.

Thanks in advance for helping out this newbie...

RuSsMaN · July 2003

http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=302-752&DID=7

$25 more, finished in beech, cherry, or black - with grill.

I think you are headed down the right path. I've had REALLY good luck with Dayton, Audax, and Vifa drivers. The Dayton 6.5 goes retardedly low (f3 of 33Hz if I recall).

As far as tweeters go, especially in an MTM array, you will be hard pressed to find a better tweeter in your price range than part #279-125 at $8 each. I say that from personal experience, it is very efficient, with good power handling.

Another high quality midbass (5.25") on the cheap, is part #299-706 . These are closeouts also. I would look at a different tweeter than the one mentioned above, unless you want to experiment with resistors to match the efficiency (87db vs 94db).

Cheers,
Russ

burdette · July 2003

I'd probably spend the extra $6 for the Dayton silk dome.

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=275-070

I don't have your personal experience, Russ.. but I do believe the Dayton tweeter has much better "support" for questions on crossovers, etc, via PartsExp and other forums. Crossover designs are already out there for the silk dome and both of Dayton's popular small woofers.

The buyout woofer isn't shielded.... and he wants a center.

http://www.partsexpress.com/pe/showdetl.cfm?&User_ID=10722661&St=4040&St2=73058649&St3=77684216&DS_ID=3&Product_ID=120518&DID=7

This is Dayton's 5.25"... more expensive, but also more information and users to access to ensure success. He could still most likely get a tweeter and two woofers and make the $60 mark with crossover (or close to it). Also, the silk and the woof are within 2dB efficiency... and using two woofers...

Here is a 2-way, 2 woofer MTM design using the Dayton silk and two 6.5" woofers, including the crossover! The woofer referenced isn't shielded, but a shielded version is available for two bucks more. For the fun and learning of building a speaker, without the stress and headaches of actual design (those get fun later and when you aren't budget constrained), this seems like a great choice. Cheap, proven-design, TONS of support on the build, tons of revelry for the sound....

http://www.partsexpress.com/projectshowcase/daytoniii/dayton_iii.html

LiquidSound · July 2003

Thanks for the link, but I'm going to do my own paint job on these as well as the, yet to be sanded, mains.

Just for reference, I can go a little over 60 to include the crossover. If needed, I can always save up a few bucks more for better equipment. It's all about the sound.

Russman, could you post a link for that dayton 6.5 you speak of?

Burdette, that's a sweet speaker project. I'd love to do that but I don't have access to woodworking tools.....yet. I'm trying to befriend a skilled cabinet maker as we speak.
By the way, Is that Dayton silk tweet shielded?

Thanks

RuSsMaN · July 2003

http://www.partsexpress.com/pe/showdetl.cfm?&User_ID=13750764&St=4873&St2=-65499256&St3=83734674&DS_ID=3&Product_ID=7769&DID=7

There is a shielded version 295-306 if need be.

The Dayton tweet isn't sheilded, but you could do that for next to nothing. The closeout dome is.

Cheers,
Russ

RuSsMaN · July 2003

Mark, not to de-rail, but for reference.

Is there a rule-of-thumb for efficiency increases using multiple identical drivers (as in an mtm/array)?

Cheers,
Russ

Sony Speaker Overhaul with Polk Drivers.

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