# First speakers - a little ambitious - curved array



## villain3g

*Curved arrays w/ powered subs*

When I finally decided to build a pair of speakers, I knew that I wanted to do something different. I also wanted it to be relatively "simple". The first thought was a single full range driver in a transmission line but they look like conventional floorstanding speakers. My second thought would be a line array but they require a mixer to combat the combing effect. This is apparently due to each driver from center being a little further from the listener’s ear. So I figured, why not have every driver equidistant from your ear. This would create a pretty nice listening experience for focal point.

Keeping cost and final impedance as factors, I went with 16 peerless 2" full range drivers per channel. I arranged them in a curved line array with a radius of 12 ft. I used 3/4" mdf for the sides and internal bracing. Again for cost, I used hardboard for the curved front and back. I wired it up in a configuration to end up with 4ohms. Attached are some pictures.

Originally I was listening to them in a larger room. About 25' wide by 14' deep. In that room they were placed wider apart and I was sitting at the designed height. At first they sounded messy but as I listened longer the speakers started to fill the range. After they had broken in, I was surprised at how deep they were going. I’m not up with all speaker terminology but their presence seemed broad and quite realistic. I tested the speakers with a variety of music. They excelled with acoustic guitar, vocal, and smooth jazz. Where they seemed to fall off is with electric guitar as in heavy metal. The distortion in the guitar is muddled. Maybe I need an equalizer for the different types of music.

Unfortunately I have to move them to my bedroom. They don't have the same presence but its still ok. While in my room played some test tracks through them. I was surprised to hear sound all the way down to 30hz. Now I don’t have any instrumentation to measure the drop-off, but I'd say it was usable down to 40hz. 

My next step is to stiffen the enclosure. Any advise from the seasoned veterans would be much appreciated. I plan on doubling the wall thickness to two layers of 3/4" mdf. For the curved baffles I want to use two layers of 1/2" mdf. I think it will bend enough. Flush mounting the drivers and back chamfering the baffle is on the list as well. I'll also round over the edges of the cabinet.

If all goes well with that, I want to incorporate a diy powered sub somewhere in the equation. Either one under a center channel or one under each the left and right speakers. 

Quite the lengthy first post. Mostly filled with noobish comments but hopefully you enjoyed it and have some input on the topic. If anything they look sexy...


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## villain3g

55 views and no comments? I’m like Johnny 5... "input Stephanie"... need to know if I’m on the right track. They sound pretty good for the first iteration. Has anyone else had a setup like these?


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## slim2fattycake

love the curve design and the amount of speakers lol. any filters or crossovers? I don't have much knowledge on this. Just wondering.

Are you going to add a finish or leave it like that?


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## tonyvdb

What kind of internal bracing do they have inside? I would be more concerned about getting that right first before concentrating on adding more layers to the outside.
The look is interesting are they ported or sealed cabinats?


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## Mike P.

I'm new to the line array scene but have been considering them. Your design is giving me ideas. I'll need to read up on the curved baffle solution for the combing effect.

What did 32 Peerless drivers cost?


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## robbo266317

A very interesting design, are they all in seperate enclosures? 
What sort of filling did you use?


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## looneybomber

If you do rebuild them, get the drivers closer together. The closer the better.

For internal bracing, get a brace that ties the two side walls together and a brace on that back wall...but being that it's curved, that'll help with rigidity.


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## villain3g

All drivers share the same enclosure. The filling is pillow stuffing material from the craft store. There is no crossover but I'm thinking of putting in a high pass filter around 80hz when I get the subs up and running.

In terms of internal structure, there are four diagonal braces. You can see their location in the pictures.

This is by no means the final product in terms of design and finish. I'll play around with port, although I don't think they will be necessary with powered subs filling in the low end.

Cost so far is around 250. My subs will bump that number up significantly. I'll start those in the next couple weeks.


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## Mike P.

What are your plans for subs? Do you have a design picked out?


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## looneybomber

villain3g said:


> All drivers share the same enclosure. The filling is pillow stuffing material from the craft store. There is no crossover but I'm thinking of putting in a high pass filter around 80hz when I get the subs up and running.


Don't worry about adding a passive HP XO. Your receiver will highpass it for you.


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## villain3g

For subs, I want to incorporate them into the base of each speaker. They will be 8" powered subs. Im hoping to use the Dayton RSS210HF-4:

Specifications: 
* Power handling: 280 watts RMS/500 watts max 
* VCdia: 2" 
* Le: .68 mH 
* Impedance: 4 ohms 
* Re: 3.3 ohms 
* Frequency range: 27 - 1,000 Hz 
* Fs: 28 Hz * Magnet weight: 50 oz. 
* SPL: 86.5 dB 2.83 V/1m, 83.5 dB 1W/1m 
* Vas: 1.14 cu. ft. 
* Qms: 3.08 
* Qes: .60 
* Qts: .50 
* Xmax: 9mm 
* Dimensions: A: 8-1/2", B: 7-1/4", C: 4-3/4". 

Im hoping to use these for both music and home theater. I want to keep the encloseres fairly small and port them as low in frequency as possible. I also want to angle the front baffel to give the illusion that the subs are on axis like the rest of the drivers.

Any recomendations?


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## Mike P.

> I want to keep the enclosures fairly small and port them as low in frequency as possible.


This is what a single RSS210HF-4 is capable of. A pair wired for an 8 ohm load could be powered by a 240 watt plate amp. The issue here is not knowing what kind of SPL levels the line array is capable of when crossed over at 80 hz. You would want to be sure a pair of RSS210HF-4's would be a good match in output for the line array.


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## villain3g

so your saying I should build an enclosure for both the subs? My goal was to keep them separate and have the arrays mounted on top. Each sub would be powered by a Dayton SA240 plate amp. They say it puts out 240w at 4ohms.

What program is that? Looks like a valuable tool to have.

Can you recommend a relatively inexpensive testing equipment to find the spl of the speakers?


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## Ricci

It's Winisd. It's free an quite popular. There is also Unibox which is a bit better but you need excel or an emulator. It's free too. there are others as well.


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## Mike P.

> so your saying I should build an enclosure for both the subs?


No, the above model is one RSS210HF-4 in 2.5 cu.ft. It would only take 50 watts to reach Xmax with one sub, both could be powered by a single 240 watt plate amp.


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## villain3g

I just ordered a pair of Peerless 830452 XLS 10" Subwoofers and a pair of Dayton SA240 240W Subwoofer Amplifiers. The subs had a much lower frequency than the other ones i was looking at. Down to 19hz supposedly. Im going to start with a simple sealed boxes. Once I get bored with them, Ill add some downward firing ports.


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## Mike P.

What size enclosure are you considering?


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## villain3g

Im thinking 1.5 cubic ft. I tried winISD. It seemed like volume didn’t affect the freq response too much. I pick the dimensions based purely on aesthetics within relation to the speakers. I’ve got the tuned freq to 19hz. That puts the difference in volume from loudest to softest about 6db. I don’t know if that’s noticeable. Is there a better design to get a flat freq response? Can I have a second port tuned to 30hz? Maybe a transmission line or a passive radiator. Have you had any experience with them?


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## Mike P.

You don't have the Re, BL, and the Vas is wrong in your file.

This is 1.5 net cu.ft. tuned to 20 hz with a slot port that is 1" high, 7" wide and 29" long. Input power is 240 watts with a high pass filter at 18 hz. 

Here is the driver file, save it to the Drivers folder in WinISD

View attachment Peerless 830452.wdr


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## villain3g

now thats a much nicer curve, Thanks!


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## slim2fattycake

Mike's the man. He'll always help out.


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## villain3g

Now I just wish I could get to work... Im kind of on vacation and away from home. It tough having all these ideas in your head and not being able to implement them. Also, I miss listening to my new speakers. Monday will be a fun day.


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## ampire

One of those on its side would make a sweet center channel probably depending on room size.


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## villain3g

The first one was set up as a center until I got the other one finished. It created a strange sensation that the sound was inside my head. Weird but thats the only way I can describe it. Once I get these subs done, Ill make a center channel just like the fronts. Ive been kicking around some bipole/dipole surround ideas. Maybe similar in design to the fronts but have 8 drivers on the front and 8 on the back. I dont know, We'll see.


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## villain3g

Subs are done. They wound up to be about 1.25 cubic ft internal volume with a rectangular port thats 11 x .75 x 33. I filled it with some polyfill and spray glued 1" foam the the interior walls. Theres a brace going from top to bottom and one going side to side. Construction material is 3/4mdf and the front baffel is doubled up. As you can see in the pictures, I was limited in size due to aesthetics. I think the came out well. 

The greatest improvement came when i bought my new recieiver. Its a denon 1709. Picked it up for $200. I couldnt pass that up. I chose it not only for the price but it also comes with audessy. I figured i needed some equilization for the arrays to sound right. Overall they sound great. I have them crossed over at 60hz. The bass is well controlled. Not boomy at all. I had a 15" klh sub and these blow it out of the water. There is some port noise. Maybe rounding over the port will solve that. The greatest impact is with movies and explosions. you can feel the bass more so with these that my klh.

Next step is redoing the front and back baffels on the arrays. Then going on to the center channel and surrounds. Also thinking of wiring up a selector switch on the fronts to run them at 8 or 4 ohms. The goal is to run the amp bridged for the left and right arrays.


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## Mike P.

Looks good! Rounding over the port will definitely help.


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## JCD

The combination looks really good. 

Will you be painting them?

I also had a suggestion -- putting some mopads under the array. That should isolate the sub from the speaker.

But really, that just look so cool.


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## soundemon

Very cool! not what I'd pictured when I read the title!


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## StereoClarity

Very nice concept! I've always been intrigued by arrays. I agree with Jacen, isolating the arrays form the sub is a priority. You could use a spike system and integrate it into the top part of the sub. Rounding over the port exit will help as well.

Have you stuffed the enclosures at all? Did I miss that?


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## Owen Bartley

Grant, those are really cool looking speakers. In your redesign, I'd second the advice to move the drivers closer together, and to work on some bracing before you double up the thickness of the MDF walls. I don't think with such a small panel you'll have many problems, especially if it's well braced internally. They really do look awesome though. What are you thinking for finish?


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## StereoClarity

Owen Bartley said:


> In your redesign, I'd *second* the advice to move the drivers closer together


Third'd...lol

Getting them closer together will help reduce lobing.


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## villain3g

Thanks everyone for the feedback. I did stuff the both enclosures with polyfill. I don't know the exact amount. I know that there’s about the same amount in each. The subs also have some fill in addition to 1" foam on the inner cavity.

Right now the subs are far superior to the towers. After reading up further on line arrays, it looks like I've gone against the grain on the key concepts. My next attempt at a line array will be to have a two way setup. The lines must be longer to really get the benefits from the line. I'm also toying with the idea of active crossovers and bi-amping.


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## StereoClarity

villain3g said:


> Right now the subs are far superior to the towers.


Don't feel bad buddy. Those Peerless are hard to outclass! I have a pair of the 12" version of those subs and they are just plain beautiful. True and honest music.


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## Endesereth

Wow! nice job, how do they sound?


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## villain3g

They sound pretty good but with the spacing of the drivers, comb-filtering starts around 6khz. My plan is to place a Dayton PT2C-8 at the center of the array and cross it at 5khz. This should really clear things up in the upper octaves.

While I have little knowledge of speaker design, I have even less in crossover design. From what I've read, a fourth order crossover has a very steep slope. But I’m concerned about this "phase shift". What does that mean? Is it noticeable? Is there a way to negate this shift?

What do you all recommend?


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## enigmaticEntity.

Phase shift is very noticeable if it is of the wrong angle. Most cross overs are designed to have 180 or 360 degree phase shifts. In this way, the phase shifts can be eliminated by either swapping the polarity of the cables in the case of the 180 degree phase shift, or you can build a fourth order Linkwitz-Riley or Linear-Phase cross over, which have 360 degree phase shifts and therefore no re-wiring.

Linkwitz-Riley crossovers are the most popular.

http://www.ajdesigner.com/crossover/crossoverfourth.php


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## villain3g

Second iteration. Two-way, bi-amped, 24db passive crossover at 5khz, and curved for time alignment.


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## yourgrandma

Sweet. I love epic looking speakers. Good work on the cabinets. How are you going to mount the ribbon on the curves face? Seems like the perfect job for a mill.


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## villain3g

Thanks. Im thinking of making a jig for my plunge router. It will hug the sides and be flat on top with a lip for the router to follow. I don't know, we'll see. Epic... good word. I wanted something that looked different. Im not too sure on the finish yet though.


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## villain3g

I've got them running. I went with a straight baffle in the end. It seems to have a more consistent sound when moving through the listening area. The addition of the tweeters is the most significant. Where there was an annoying confusion in metal rock and complex orchestral pieces is now a pleasant accuracy. My only concern is if I'm actually getting down to the subs. Most likely not.


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## ridecolby

Great looking project. It is unfortunate that you had to go with a flat baffle because the curved one looked really cool. What is your plan for a center to match up with these? How about surrounds?


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## ronbon

Your arrays look to me very similar to the column speakers I have seen for p.a. work. They would be hung facing out and down to the back rows of an auditorium. The distance between the line of speakers created a phase distortion that tended to cancel the higher frequencies of the outer speakers in all but the direct line of fire of the array. This helped eliminate feed back during live performances. Maybe this is why the sound seems to come from inside your head. Either that, or you humming along

Ron


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## Yad

Grant, how did you make a curved face panel ? Does usual MDF is flexible-enough ?


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## villain3g

I cut the sides with a jigsaw and sanded them together. The front was 1/4" hardboard but if I did it again I'd use 1/2" mdf.


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## villain3g

They definately don't have the same visual effect... Maybe I'll rig up the old enclosures to work for something. I've got these bi-amped and crossed at 5k.


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## Counterfiend

I think that you could still use the curved baffle for the speakers if you wanted to.
I'm not sure if you can see it, but you basically just make cuts almost all the way through the wood leaving just enough of the front of the MDF to stay together.
I'm just not sure how well that will stay together once you start to put the holes for the speakers









Pretty similar to what was done to this MDF to make it snake


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## villain3g

I made some measurements today. Denon avr-1709, rs spl meter, REW. Ran some sweeps with and without Audyssey. There is a trough from 300 down to 80 where the sub takes over. Audyssey doesn't help this dip much but it really flattens out the subs response. The freq response of the speaker is as flat as I would have liked but they sure do fill the room with sound. It seems like sound is coming from all directions. I'm considering modifying these to be similar in design to the McINTOSH XR200s. I'm thinking 3 or 4 6.5" drivers in the base with a line of mid-ranges and a line of tweeters. We'll see... The first graph is without Audyssey.


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