Peerless 830668 10"s bi-amped music only system

[mikemarion]

Hi All-

I've been lurking for quite awhile but this is my first post here.

I bought a pair of Peerless 830668 10" subs for my bi-amped home audio (music only) rig.

I am replacing a pair of 15" PA speakers (with the tweeters unplugged) crossed at 125hz or so with the Rane MX22 active x-over.... so, I think fidelity should improve.

In the past I have built ported enclosures, but as this is a music only system I'm thinking of going sealed.

The amp driving the subs is a Soundcraftsmen S860 that does 205 at 8 ohms.

The box that seems to fit the space comes out to be 1.76 cu ft (not figuring for driver displacement). At 22 inches tall, it is 3 inches shorter than the current subs. I think that is ok, since I angle up the speakers. I could make the tweeters ear level but the WAF will suffer.

I listen to electronic music, 80s, techno... so, I don't think I need to go down to 20hz. (i like a bit of boom and a "popular sound")

I solicit your feedback on:
-Enclosure type (sealed vs. ported)
-Volume of the enclosure
-Tweeter angle vs. level
-etc.

Thanks in advance!

Here are the current plans:

This is how the system looks currently:

Electronics (close up):

The satellite speaker build:
https://plus.google.com/u/0/photos/116825914925211100681/albums/5405921792152051425

42l sample box:
http://www.tymphany.com/files/resources/appnotes/Appnote_830668.pdf

 

[wintermute]

Hi Mike and welcome If you haven't already done so I would suggest downloading one of the sim programs and putting the T/S specs of the woofers into it and looking at what you get with sealed/vented.

You have a fair amount of power available so running sealed with a Linkwitz transform may be an option.

I personally use unibox for modelling (needs microsoft excell) a lot of people use winisdpro which is a standalone app.

I'm not experienced with using tilt rather than height to get tweeters essenitally "on axis" at the listening position (mine are at ear height when seated). I would think the main trade off with tilting up would be changes to ceiling bounce (which may work out well) floor bounce would I guess be reduced.

Tony.

 

[mikemarion]

Thanks Tony.

I have used WinISDPro Alpha before. So, I'll try that.

Here is the driver T/S using the specs from Madisound:

Here are two plots. The yellow line is the default (unacceptably large at 6.7 cu ft) and then my desired size (in green) at 1.75 cu ft. F3 is 44.3Hz:

So, this backs up what I've seen online... The question is: Will I be happy with a speaker with an F3 of 44Hz or should I look at a ported design?

 

[Drew Eckhardt]

So, this backs up what I've seen online... The question is: Will I be happy with a speaker with an F3 of 44Hz or should I look at a ported design?

You should loose your fear of Linkwitz transforms and gain the ability to pick box size and extension mostly independently where box size can be used as a tool to make the amplifier clip before the driver bottoms.

Ex: Linkwitz Pluto+. Peerless 830668, .5 cubic feet, second order high pass response with F = 20Hz, Q = .5, F3 = 30Hz.

Pluto + subwoofer

 

[mikemarion]

I have the DEQ2496 that has five band of parametric equalization available... would that work to provide the the necessary subwoofer equalization so that I can avoid the Linkwitz transforms that I am afraid of.

 

[mikemarion]

The design goals that won out were:
(1) I am building a speaker stand as well as a sub
(2) The 3/4 MFD I purchased was cut roughly into quarters
(3) I only want to measure to a 1/4" and then use a router to clean up the edges once assembled

Here are the plans:

I won't start cutting until later today or tomorrow so feedback is still appreciated.

 

[mikemarion]

Yesterday I cut all the panels. Starting assembly today.

The screws you see are all internal, just so I didn't have to clamp the glue blocks in place while they dry.

Photos:

 

[mikemarion]

I bought a 50oz pack of POLY-FIL at Walmart to stuff the speaker enclosures. Any guess how much I should use?

Here is the progress:

 

[mikemarion]

Online I see people recommend stuffing with .5 to 1.5 pounds per cu ft.
If I use all 50oz that I bought I am at about .8 or .9 pounds per cu ft.

Tonight I can clean up the edges with the router and sand the enclosure.

Here us is what it looks like now:

 

[wintermute]

Hi Milke are you going to put any cross bracing in there? You will get panel resonsonces with a box that big without something tying opposite sides together

On the stuffing, there is an active thread at the moment in multiway discussing that very point

Tony.

 

[mikemarion]

Hi Milke are you going to put any cross bracing in there? You will get panel resonsonces with a box that big without something tying opposite sides together

Nope. The box is glued together with no shelf brace. I used boxnotes to calculate resonances and I though there was no resonance below 300hz. I will run it through boxnotes again and check.

On the stuffing, there is an active thread at the moment in multiway discussing that very point

Awesome. I guess I should have checked here first.

Thanks Tony, I appreciate the feedback!

 

[wintermute]

ok I forgot about this being a sub, what frequency are you going to run it up too? You might still need to consider harmonics, as I haven't ever done a box that is purely a sub I've not ever thought about that..

Tony.

 

[mikemarion]

ok I forgot about this being a sub, what frequency are you going to run it up too? You might still need to consider harmonics, as I haven't ever done a box that is purely a sub I've not ever thought about that.

The old sub was crossed at 125hz @ 24 db/oct.

Almost done! Installing the 2nd driver.... photos soon.

 

[mikemarion]

First impressions...

1. Lower efficiency- had to turn down the amp that runs the tops.
2. Less boomy

Photos:

An externally hosted image should be here but it was not working when we last tested it.

 

[mikemarion]

Well, I am a bit disappointed. I find myself playing the system much louder trying to get the same effect.

So, I hooked up the old crappy 15" woofers again and I prefer them (much warmer at the 100hz region). Sure, the Peerless drivers are more probably way more accurate but far less fun.

I might try a pair of Dayton Audio 10" Titanic Mk III that I own in these enclosures.
Dayton Audio TIT280C-4 10" Titanic Mk III Subwoofer 4 Ohm 295-414

I'll probably run the T/S parameters through Win ISD Pro Alpha... since it is quire a bit of work to pull the Dayton drivers from the HT sub and bedroom system sub. Then again modeling only goes so far and since no wood needs to be cut, swapping drivers is probably the most definitive test.

The other alternative is to remove some of the stuffing or even port these enclosures... but the part I am missing seems to be in the upper bass.

 

[mikemarion]

nevermind.

I pull all the stuffing out of the speakers and they sound a million times better.

I might add some back, maybe not.

 

[wintermute]

Interesting, I had a similar experience with my 5" drivers stuffing (possibly over stuffing) tended to kill the sound.

another thought as well, Is the gain on your sub amp the same as the gain on your other amp? forget about the levels you are setting with the crossover, if the gain on the sub amp is lower than on the main amp when you turn it up your bass will get weaker... if you set it at lower levels.

Tony.

 

[Barleywater]

nevermind.

I pull all the stuffing out of the speakers and they sound a million times better.

I might add some back, maybe not.

Going Linkwitz route is much better. DEQ allows sufficient control to smooth out and extend bass as desired. Box you are using is too big and too light to avoid panel resonances.

Do you have measurements of results?

Regards,

Andrew

 

[Michael Chua]

I listen to electronic music, 80s, techno... so, I don't think I need to go down to 20hz. (i like a bit of boom and a "popular sound")

I haven't tried the 830668 but my guess is that being a subwoofer, it is probably more optimized for the lower frequencies like in the 30-40Hz region. Great for movies but I find such drivers unsuitable for music. There's no punch and definition in the midbass.

For music, my preference is to use a woofer instead of a subwoofer. With the right woofer, it's possible to achieve a good balance between the low bass (40-50Hz) and the midbass (90-200Hz).

One such woofer is the 8" Usher 8137A. I have it in a 25L 3-way ported box. Very dynamic, punchy bass. If you prefer 10", check out SB Acoustics. I haven't tried them but judging from the specs, they have some models that look promising.

Regards
Mike

 

[mikemarion]

Interesting, I had a similar experience with my 5" drivers stuffing (possibly over stuffing) tended to kill the sound.

another thought as well, Is the gain on your sub amp the same as the gain on your other amp? forget about the levels you are setting with the crossover, if the gain on the sub amp is lower than on the main amp when you turn it up your bass will get weaker... if you set it at lower levels.

Tony.

The bass amp does not have input level contols. So, I set the bass level and then bring up the input level on the amp for the tops. The levels seems to track together pretty well.