diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Full Range (http://www.diyaudio.com/forums/full-range/)
-   -   Which 8" full range or coaxial for $150/less? (http://www.diyaudio.com/forums/full-range/191665-8-full-range-coaxial-150-less.html)

CZ Eddie 28th June 2011 02:06 AM

Which 8" full range or coaxial for $150/less?
 
1 Attachment(s)
Guys, I need suggestions for a $150 or less 8" full range or coaxial.
This will be used primarily for pop music and home theater. Not for me, but some friends.

Needs to have decent off-axis response.

Unfortunately, these will be built into an entertainment center and spaced much closer together than ideal. See picture below for what I'm talking about. I will at least space the speakers as far apart as possible, in their respective cubby hole enclosures. I will be making the enclosures from 3/4" MDF.
A 15" sub will be located in the bottom cubby hole.

This room is about 3500-4000 cu.ft and leads to a kitchen and dining room, so probably more like close to 7000-8000 cu.ft. Pretty un-ideal. So I'm looking for best dynamics possible. We are NOT allowed to place the speakers anywhere other than the cubby holes. :(

Assuming a 40hz tune & 8" speakers, each cubby hole has 1.8 cu.ft. internal volume still available.
Not sure which AVR will be used yet, but likely something rated around 80 to 100W/channel. Like an Onkyo TX-SR6XX or 7XX.

BHTX 28th June 2011 07:38 AM

I'd definitely try to fill the holes completely, preferably with enclosure volume, to avoid nasty resonances. Plus, it'd pretty much be an infinite baffle (although perhaps not ideal as far as diffraction goes), which has plenty of advantages (smoother overall response, lack of baffle step issues, reinforcement of low frequencies, sometimes better distribution of low frequencies, etc). Also, there are some ways of attempting to get a good stereo image with the loudspeakers placed close together, some of which I've actually found somewhat acceptable and interesting.. this might not be very feasible for you though. Exhausted, as usual, so it's tough for me to think clearly, as usual. I'll post back if something pops into my head.

BHTX 28th June 2011 08:34 AM

Are those multi-channel receivers? I first assumed this was just going to be a 2.1 channel system.

Yes, from your description, I'd agree that good off-axis response would be a good characteristic for this system to have. That pretty much rules out full-range drivers, other than maybe 3", which unless used in an unconventional manner as a tweeter with a low shallow slope crossover to a wideband midbass driver, it probably wouldn't end up being much better than what's already in the picture. Such a system probably wouldn't meet your criteria for "dynamics" either. On the other hand, early floor reflections might be an issue, especially with coaxials. A large unusually thick rug might help alleviate some of this.

As far as coaxials go, there isn't much to choose from in the consumer market, but plenty in the pro audio / live sound market. However, they tend to require very complex crossovers, along with high acoustic slopes due to the use of a compression driver. Not sure if this is your cup of tea, or if it's within your capability. But yes, I do see where the use of a coaxial would be beneficial. Some of the manufacturers have passive crossovers available, although they're probably far from ideal. 8" you say? Quite a few of those. The Eminence models might seem like a good deal at first glance, but as is common with these dual concentric drivers, the high frequency response from a compression driver when used with these models is particularly horrific, imo. With that said.. Beyma, B&C, BMS, Ciare, P.Audio, Eighteen Sound, and Radian come to mind, and I'm sure I've likely missed a couple. Prices for these drivers tend to get pretty steep though, particularly when it comes with a compression driver. You might do best searching for a trusted design for one of these coaxials. If I'm not mistaken, there might be some info out there for the B&C 8CXT. I know for certain that B&C, Beyma, and Radian all provide passive crossover networks for some of their coaxial units, if you must go that route.

It seems as though the site I often refer to for measurements of such drivers is down at the moment.

As far as the subwoofer goes, I'd suggest a little something besides the usual for a potentially great sounding system.. a good compromise between good upper frequency response of the raw driver itself versus excursion and output capability, low inductance is a plus.. and then use no more than a 2nd order low-pass on the subwoofer, and try to run the 8" coaxials without an electrical high-pass filter, other than the natural 2nd order acoustic high-pass from their enclosure (i avoid 4th order slopes if at all possible.. I find them very distracting, fake and tubby sounding, unmusical, just overall nasty, etc.. it just ruins the bass for me. Then again, as with everything else stated above, this is all just my personal opinion). Especially with the woofer being right between the mains and in such close proximity, mating a subwoofer to them in this fashion should be very easy and yield good results.

chris661 28th June 2011 09:15 AM

Why 8"s?

You're using a 15" woofer, so why not take the crossover up to more like 200Hz, and give the mid-highs an easier time? The close proximity allows this, so I see no reason why not.

CZ Eddie 28th June 2011 11:45 AM

Guys, thanks for the suggestions.

Yes, multi-channel amplifier. :)

As far as using smaller drivers and bringing the 15" sub low pass up higher, this was suggested on another forum (parts express). The poster recommended the Tang Band W5-1611SA 5" Full Range Driver with a 150hz low pass on the sub.

Tang Band W5-1611SA 5" Full Range Driver

The only reason I haven't considered it further is because I have personally never run higher than a 80hz low pass on any sub, so I wasn't sure how it would sound. Or when I have, it directed voices over to the corner of the room where my sub was. I suppose that won't actually be an issue here with the sub located between the drivers.
Also, I assumed with the large volume I have available that an 8" driver would be best (9" height available).

The subwoofer btw is a DIY clone of the AV123 MFW-15 subwoofer. I've already purchased the OEM amplifier and am waiting to purchase the OEM woofer as soon as I get a response from the seller.

I will continue to respond to the thread today but be aware my responses will be short, since I'll be using my mobile phone to respond.
I promised them I would provide the best possible sound setup with the horrible restrictions & cost $$$ ceiling.
In return they have promised their next house will have a dedicated home theater/music room. :D

18Hurts 28th June 2011 02:56 PM

So you want to cram a stereo pair of speakers in a cubby hole? :eek:

Understood, I built a center channel speaker in the WAF location, 30"W x 6.5" tall and 15" deep--a "2.5 way" sealed box with four 5" woofers crossed at 1.8 KHz to a 30mm WaveCor tweeter. Two of the woofers roll off at 450Hz 6/dB (coil) for baffle-step correction and it works very well.

Full ranges are fine but you said the evil word "off-axis response". The MTM arrays work well in horizontal position if you follow the rules as far as beaming goes--horizontal forces the issue.

Another option is to use a conventional 2-way with tweeter and 4" midwoofer in vertical orientation at the edges. Cross two 6" woofers at around 300 to 400 Hz to get your baffle step. Push the pair of 6" woofers toward the center then cross your sub at 80 to 100 Hz. The vertical tweeter-mid will solve the beaming issues when laying speakers on their side.

I considered doing the same thing for my WAF center channel--the off-axis response to cover the area I needed covering killed that idea quickly. Also consider the people might turn the subwoofer off for music, since they listen to pop...the dual 6" woofers would take the load.

chops 28th June 2011 03:11 PM

I have news for you as far as the AV123 MFW-15 subwoofer is concerned. That "OEM" driver is the same exact driver as this one from PE. I know, I have two of them sitting in my old bedroom at my father's house. Same numbers stamped on the cone and basket of the PE driver and "OEM" AV123 driver. I can't remember where I saw it now (it was a couple years ago), but both drivers' measurements came out identical, further proving they are one in the same.

Dayton Audio DVC385-88 15" DVC Series Subwoofer

I'm not saying the 15" driver is bad or anything, but I don't think it's the best match for what you're wanting to run with it. There's better options out there, like the ones below.


If I were to build a sub to match up good with the quickness and dynamics of fullrange drivers, especially mounted that close to the sub, I would go with one of these drivers, in this order... I would also build a sealed enclosure for them, not ported due to the limited space and possible noise from the port(s).

1) Peerless 830500 12" XLS Subwoofer

2) Dayton Audio RSS315HF-4 12" Reference HF Subwoofer 4 Ohm High Fidelity Reference Series



As for the mains, I would get a pair of these PER channel...

Dayton Audio PS220-8 8" Point Source Full-Range Neo Driver

Along with a nice tweeter like this...

Dayton Audio PT2C-8 Planar Tweeter


Build them into a sealed enclosure MTM style (horizontal obviously). This style with those planar tweeters will give you a nice, wide horizontal and narrow vertical dispersion which is what you want and NEED in this kind of limited setup. I would do a simple passive 1st order series crossover for them.

And speaking of crossovers, I would cross them over to the sub around 150-250Hz since they are all in close proximity to each other. That relieves the fullrangers of heavy lifting and allowing them to do those dynamics without much stress, plus either one of the sub drivers mentioned above can easily and cleanly handle those frequencies.

CZ Eddie 28th June 2011 04:56 PM

Holy moly you guys are murdering the $150 budget!
Cool tips/ideas though.

borispm 28th June 2011 05:02 PM

For great off axis, try Tangband's flat cone drivers. Another good candidate is ScanSpeak's 4" glass fiber cone mid/fullrange driver. You can in fact save some money with the Vifa 3 1/2" glass fiber cone fullrange anyway. Never expect good off axis from large drivers, I would say. With the subwoofer so close to the stereo drivers, you can cross them higher, even at around 200Hz, I would say.

chops 28th June 2011 05:08 PM

Quote:

Originally Posted by CZ Eddie (Post 2622301)
Holy moly you guys are murdering the $150 budget!
Cool tips/ideas though.

How? You said $150 for fullrange or coaxial. Is that for the pair of per driver? We don't know.


Quote:

Originally Posted by borispm (Post 2622313)
For great off axis, try Tangband's flat cone drivers. Another good candidate is ScanSpeak's 4" glass fiber cone mid/fullrange driver. You can in fact save some money with the Vifa 3 1/2" glass fiber cone fullrange anyway. Never expect good off axis from large drivers, I would say. With the subwoofer so close to the stereo drivers, you can cross them higher, even at around 200Hz, I would say.

Going with those drivers would work great for off-axis, however their poor efficiency kills any chances of the system being dynamic.


All times are GMT. The time now is 06:06 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2