Thoughts on an amateurs design!! advice appreciated!

[Oscar_M]

G'day guys,

I'm quite new to the speaker building game, but I have some woodworking experience and a fondness of music so I figured this would be a good project!

Given my lack of experience with speaker components and crossover design I have opted to use pre-designed kits offered by Parts-Express -

The design (attached) utilizes the "Dayton Audio RS722 Speaker Kit w/o Cabinet" to cater for the midbass-high. Drivers to be located in their own 1cuft seperate compartment, and a "Dayton Audio RSS265HF-4 10inch subwoofer" in the lower compartment, either 1cuft sealed, or 1.5-2.0cuft vented compartment. I plan to power the subwoofers with a dayton audio SA1000 amplifier and power the rs722 kit with a 100watt per channel home theatre reciever. (hopefully this will be upgraded in the near future)

My concerns revolve around the use of a subwoofer incorporated into the mains, and whether the crossover for the rs722 would pair nicely with the subwoofers? I'm hoping the subwoofers bring the chesty impact up a few notches for music, and provide reasonable thump for home theatre.

Any help/advice would be appreciated!

the cabinets will be finished with a a 2-pac paint and a glass/acrylic speaker cover. (colours or veneer perhaps I am yet to decide on!)

[billfitzmaurice]

Re: Thoughts on an amateurs design!! advice appreciated!

My concerns revolve around the use of a subwoofer incorporated into the mains

The best placement for subwoofers and mains seldom coincide, so all things considered separate subs and mains will usually give a better result.

[donradick]

Re: Thoughts on an amateurs design!! advice appreciated!

Really great project for your first time!
I would never disagree with Bill Fitzmaurice on bass issues, but I would advise initially putting the 722s on top of the
bass bins - that may give a better integration "top to bottom". If you notice that you have uneven bass response in your
normal listening positions you can separate the bass bins and the 722s and move the subs around.

In any case, I believe that you want to use your HTR and run the 722s on "small" to integrate with the subs.

[Oscar_M]

Re: Thoughts on an amateurs design!! advice appreciated!

Thanks for confirming my suspicions, ill modify the design to allow for alternative subwoofer placement. Any suggestions for a musical, punchy subwoofer solution? Price is not a major factor.

Thanks in advance

[donradick]

Re: Thoughts on an amateurs design!! advice appreciated!

Thanks for confirming my suspicions, ill modify the design to allow for alternative subwoofer placement. Any suggestions for a musical, punchy subwoofer solution? Price is not a major factor.

Thanks in advance

The Dayton Reference designs will give the highest sound quality, and there are several alternatives cheaper and more expensive.
The 12 inch version should be a good match for your 722s.
http://www.parts-express.com/dayton-...r-kit--300-742

Or you can build your own box, add a sub driver and plate amp.
There are many alternative sub designs in this forum.

[Oscar_M]

Re: Thoughts on an amateurs design!! advice appreciated!

Thanks for the suggestion, I have heard (myth?) That a 10 inch Driver will provide tighter/more responsive bass than its 12" counterpart. Do you think this statement had any validity when comparing the hf series subwoofers?

[isaeagle4031]

Re: Thoughts on an amateurs design!! advice appreciated!

You are or right, that is a myth.

[[email protected]]

Re: Thoughts on an amateurs design!! advice appreciated!

The amp you have in mind does have EQ so that should help integration.

[ReissM]

Re: Thoughts on an amateurs design!! advice appreciated!

I'm quite new to the speaker building game, but I have some woodworking experience and a fondness of music so I figured this would be a good project!

Any help/advice would be appreciated!

Welcome! Congratulations on your new hobby/addiction. Speaker design & building is extremely rewarding and loads of fun. It looks like you’ve thought about this design for a while. Looks very nice.

Some quick notes:
I ran the Thiele/Small parameters of your chosen woofer, RSS265HF-4, through UniBox 4.08 (Free Software). Double check me on this… UniBox recommends about 25 Liters (0.9 ft^3) for a sealed box, and 71 Liters (2.5 ft^3) for a vented enclosure.

SEALED: If you go with a 25 Liter sealed box, you’ll reach the X-max excursion limits of that woofer by the time you get up to about 200 Watts. You mentioned that you plan to use the SA1000 Amp (with 1000 Watts). That might be a bit overkill. You could get away with a significantly cheaper 250W or 300W amp and never know the difference.

PORTED: If you go with a ported 71 Liter box, you’ll still reach X-max cone excursion at around 250 Watts.*** So, maybe save the SA1000 for next year when you build a monster 18” house shaker. LOL.

I tend to utilize amps with 6dB of bass boost on my sealed subwoofers, but I skip the bass boost on my ported sub designs.

I like your design… keep ‘em coming.


*** I’m referring to the frequencies above 20Hz… as most ported designs have excursion issues below the port tuning freq. A subsonic filter can help with that if needed.

[johnastockman]

Re: Thoughts on an amateurs design!! advice appreciated!

No. Another myth that has been offered up as fact, along with a bunch of anecdotal evidence. I have a long background in retail audio, and not at a big-box audio emporium. My blog contains details, experiences and info I have gleaned from my time there.

I agree with having the ability to experiment with sub placement. Each room is different and present room nodes and issues that can negatively affect the bass performance and sound quality (SQ). Placement can alleviate room nodes that accentuate certain frequencies, giving a boomy/tubby SQ. I've assembled that kit (with the cabinets) for a couple friends. It's well done, the cabinets are very solid and look terrific. The overall SQ is quite good with the supplied crossover (XO). Another option: some very-respected designers have developed XOs for the RS180S & RS28A MTM config. I cannot recall the specifics right now, but I'm sure some of the guys can point you to the XO and the design itself. If it were me, I'd be tempted to use those drivers with the accomplished-designer's XO alignment. Not saying the XO development for the stock '722 kit isn't good, but there are XO options that you might want to look at. Love the cabinets you worked up, very distinctive. Friends, family and myself have been knocked silly with the subs I've made using the RSS315HF-4 (12") driver in a 2.5 ft3 sealed & well-braced cabinet with the 500W parametric EQ amp. The 10" RSS driver is equally adept in a proper enclosure, also. Before you get further, go to this link:

https://sites.google.com/site/undefinition/diy

Read everything under "Resources" at the right. It will likely take less time to read through those than it took to read this verbose post. Paul's writings in this area are super-helpful & will give you a better understanding about speaker building/designing in general and dispel many myths and BS that OEM speaker companies have offered up as fact for years. Since I worked where I did for so long, I have a unique perspective regarding the popular/recognized speaker brands and commercial speakers in general, and it's not based on conjecture or anecdotal evidence. There are companies that dispense with the hype and offer great build quality and SQ, but there not as easily found as they used to be, with the rise of the big-box audio stores. Good luck and welcome to the addiction, I mean hobby. I look forward to seeing your progress and end-result. Don't hesitate to ask ?'s if you need more info or clarification. I came here about 14 years ago, asking similar questions about XOs and why I wasn't getting decent SQ from my own efforts. Start with Paul's write-ups as a "primer". "Speaker Building 201" by Ray Alden is also a great starting-out resource.


John A.

[Oscar_M]

Re: Thoughts on an amateurs design!! advice appreciated!

Wow! Absolutely thrilled with the advice and info!

Thanks guys for clearing up the driver size myth

John I will have a read through the link you posted. And designers specifically you would recommend me checking out re the XOvers?

Reiss I agree the sa1000 is overkill but being in Australia there is a substantial shipping charge so I figured I would invest a little more money to cover the more... Ambitious audio ventures should my habit become an addiction...

Thanks again!

[Adam_G]

Re: Thoughts on an amateurs design!! advice appreciated!

Wow! Absolutely thrilled with the advice and info!

Thanks guys for clearing up the driver size myth

John I will have a read through the link you posted. And designers specifically you would recommend me checking out re the XOvers?

Reiss I agree the sa1000 is overkill but being in Australia there is a substantial shipping charge so I figured I would invest a little more money to cover the more... Ambitious audio ventures should my habit become an addiction...

Thanks again!

Go big or go home! It's expensive upfront but fun once you get going!

[donradick]

Re: Thoughts on an amateurs design!! advice appreciated!

Jeff Bagby (The Master) did an RS180 / RB28A MTM design that is pretty much considered the ultimate.
As far as I know, the RS28A crossover is pretty similar to RS28F crossovers (I may be wrong about that)

OOPs, forgot the link!

http://techtalk.parts-express.com/sh...180-MTM-Design