First Time DIY Needs Advice

[JMRod]

Hello,

I am working on putting together my first real (currently have HTIB) HTS. I have been doing research for a couple weeks now. I am convinced I want to try building my own speakers.

I am planning on purchasing a refurb Onkyo TX-NR709 for $450. THe other option i considered was a new Onkyo 616 for $390. I believe the former is a better buy.

My budget for getting my speakers started is $1500 with room to add/grow in the future. My living room is large 22'x22' ish. It is connected to an adjacent kitchen with only a 3ft wall in between. I understand that my budget probably doesnt allow for a "proper" system for my room but I plan on getting the best I can with that budget for now.

I have been told that Ascend Acoustics 340 L/C/R would be a good place to start and eventually adding their HTM200's for the rears. Also, I would eventually a sub if it doesnt fit into the budget up front.

The advice I seek is in the selection of a comparable DIY design. There are tons of designs out there and its hard to choose. I am still very interested in DIY route. I have been looking at the TRITRIX set. But the "budget" label makes me wonder if I will be happy with them. The other set that has caught my attention from the same design team is the AviaTrix. They seem to be based off the TRITRIX but a step up with better drivers. What DIY speaker are comparable to the Ascend Acoustics for around the same price point?

I am looking for a system that will serve as a 5.1 and also great for music listening. I plan on driving them with the receiver for now until I can afford an amp if it is required.

Thank you in advance for any guidance.

[oneplustwo]

My bet is that you would be happy with the Tritrix or the Aviatrix. The Ascends don't look like anything particularly fancy. I don't know them well, but it looks like electrolytic caps in the crossover which typically doesn't indicates something particularly high end. Or even middle end on this forum at least.

If you're worried about outgrowing the tritrix, you could always step up to one of the MTM designs that use Dayton reference series drivers. You'd probably still be under budget even with them.

[Lex]

Welcome Rod. Stick with these guys, they won't steer you wrong. Read, ask questions, learn and build.

Doug
Admin

[JMRod]

My bet is that you would be happy with the Tritrix or the Aviatrix. The Ascends don't look like anything particularly fancy. I don't know them well, but it looks like electrolytic caps in the crossover which typically doesn't indicates something particularly high end. Or even middle end on this forum at least.

If you're worried about outgrowing the tritrix, you could always step up to one of the MTM designs that use Dayton reference series drivers. You'd probably still be under budget even with them.

Thank for the feedback.

I will look into the upgraded Tritrix. I thought that was what the Aviatrix are suppose to be.

It seems that any of these speakers would be fine being driven by the Onkyo 709 receiver I am considering. I am not sure yet how to properly size and driving amp to speakers.

[JMRod]

Welcome Rod. Stick with these guys, they won't steer you wrong. Read, ask questions, learn and build.

Doug
Admin

Thank you for the welcome.

It definitely seems like there are some very knowledgeable people on this forum. They seem helpful too.

I will continue my learning. I currently am not at a shortage of questions but I am trying my best to do my research before I ask.

[oneplustwo]

Look into the Modula MTM or the Nat P's. They're in the completed designs thread and many many folks have build threads for them.

Also, if for your first build especially, it wouldn't be a bad idea to look into 2-way designs as well. Less crossover complexity, less cost, less driver cutouts, and arguably parity performance depending on your needs.

[---k---]

I had CJD RS150 MTM side by side with a pair of Ascend 340SEs five years ago. Very similar neutral voicing. The RS150 MTM were slightly better, especially as things got more complicated. Hearing CJD's speakers put my on DIY road. I highly recommend both.

The original TriTrix are pretty long in the tooth. I think there are a lot better options. The AviaTrix are probably a good improvement, but I'm not sure the drivers are available. My/CJD Ochocinco's use the same midwoofers but with a less expensive tweeter and are amazing for the price. I really love what those speakers do for the $$.

Spend as much as you can and stick to well know designers and you'll be good.

[BeerParty]

I think you would be very happy with the AviaTrix.

The AviaTrix are available in both a MTM and a TM version, so you could build MTMs for the front and TMs for the surrounds. The crossovers have a near wall variant so you have more flexibility in placement. The mid-woofers were on back order for a while, but they seem to be available again. Either of the receivers you have will drive them fine, I use a Denon 1709 with my AviaTrix without issue.

One caution - if you are going to use these for home theater you will want to build a subwoofer. These are excellent speakers but they will not handle the low frequencies typical in modern movies. I would build the subwoofer first, then build the mains (front left and right), then build the remaining speakers.

[JMRod]

Thanks for the feedback. I am leaning towards the Aviatrix but still looking around and consider other options including those mentioned here.

I was previously consider going for a refurb Onkyo 709 for $450 instead of a 616 refurb for $390. I just found an a NEW 709 going for $249! They are also selling the 809 for $499.

It seems the biggest upgrade from the 709 to the 809 is a larger amp. Is that worth the extra $250? I am leaning towards the 709 as the better value (steal?) since they both have preamps and I can add an amp later if I want.

[AdelaaR]

Depending on room size and if you like your ears to bleed ... that 709 should have plenty power to drive relatively small speakers like the ones you mentioned if your sub will do the lower frequencies.
Any receiver with pre-outs for $249 is indeed a very good price as you can always go for bigger front speakers and a seperate poweramp later if you want.

[JMRod]

They were sold out of the receivers. Must keep shopping. Although now I have my sights on one level up (onkyo 818 or equivalent range, a unit with preamp and MultEQ XT32). Although that above my budget and would have to save a little to step up a notch.

On a side note, I was at Best Buy the other day. I was in there listening room and I was not impressed at all. I am not sure if it was their set up or the speakers but nothing I heard made me want to buy even at half the price they were selling. They had Polks, Klispch, Bose on display among their higher end speakers. I hope the budget DIY projects I am considering sound better than these.

I must say I did listen to the Bose single thin long center speaker and woofer set. I was impressed by that especially considering it is only one speaker and a sub. BUt $1500 dollars?

[fbov]

First off, nothing ever sounds the same in the showroom as it does in your living room, and that's because the room matters; size, construction, furnishings, room treatments (rugs, drapes, etc.), among others like adjacent spaces (your kitchen) and room openings (doorways, windows). And then there's speaker/listener placement...

Second, no commercial speaker sounds as good as your DIY effort on the day you finish it. A commercial speaker may sound better if you just dropped a wad of $$$ on it, or if its prettier - human sonic judgement is highly affected by non-aural cues like expecations and visual appearance. Beware of personal bias as it's a moving target.

That said, there's a large body of research that points to some fairly universal requirements for good audio:
- low linear distortion - a flat FR curve using the intended speaker/listener locations in your room
- low non-linear distortion, especially at the highest SPL level you'd like it to play.
- the ability of the speaker to achieve the desired average SPL with the headroom required to handle the dynamics of the intended program.

Linear distortion is variation in loudness across frequency. It's linear because the frequency is part of the program being played, and it's distortion when there's too much or too little of it. Things peaks and dips in FR curves, but there's more - balance. The entire curve needs to be flat, on average, from low bass to the upper limits of your hearing. This last part is highly affected by room placement, thus the emphasis on your room and it's speaker/listener locations.

Key concept for DIY is BSC - baffle step compensation. One can design speakers for in-wall mounting, or freestanding use away from all walls and furniture, but not both. The size of the "baffle" (the board that holds the speaker drivers) matters, ranging from the entire wall to an 8-12" wide panel on the front of a box. Doing DIY, look for a design family that has freestanding and on-wall/in-wall options (as well as center channel for 5.1).

Non-linear distortion is a combination of quality drivers used within their optimum frequency and loudness range. It's non-linear because the frequencies are not contained in the program, the speaker's creating them, either as harmonics of program frequencies (harmonic distortion HD), or due to interactions between prrogram frequencies (intermodulation distortion, IM). Very hard to get this data... outside of the DIY community. Here, several posters have web sites where they show test results.

Distortion plays nicely into dynamic requirements - transient response and peak power handling. As you turn it up, distortion becomes more audible, and there's more of it due to the larger cone motions required to move the air. It's a judgement call, but one that can be based on data - program preferences, room size and loudness preferences.
- classical has great dynamics, up to +30dB, but generally low average level.
- "quality" recordings of modern/contemporary music perhaps half that dynamic range, perhaps 15-20dB
- victims of the "loudness war" only have 3-6dB of dynamic range.

The idea is to match speaker sensitivity with power handling (and amp power) to your program's dynamic requirements, your loudness preferences, and room size. This can be addressed by examples already put forth:
- Tritrix is older, "classic" drivers of 130mm size, 60W system power rating and 88.8dB@1W, 1m sensitivity, before BSC (which can take as much as -6dB off that)
- Aviatrix uses very new drivers of similar size (140mm), greater power handling (80W sysem rating) and similar sensitivity (88.7dB@1W, 1m), also before BSC is applied.
- Modual MTM/NatP use modern drivers in a 180mm class, with even greater power handling (120W system) and higher sensitivity, 90dB@1W, 1m, again with no BSC.

Note that as price increases fromn $140/pr (Tritrix kit) to $285/pr (Aviatrix) to ~$400/pr (NatP's), you get higher quality drivers, greater power handling, and greater sensitivity. This progression is fairly generic - you get what you pay for.

In a 22x22 room, a center listening position will be ~14'/4m from a speaker placed 2' from adjacent walls. Ignoring wall reflections... sound falls off -6dB for each doubling of distance (inverse square law), so you lose -12dB from each speaker due to distance. However, you gain it all back if you use 4 speakers and amps. Room reflections will only increase SPL, so let's ignore them for now. Based on rated power:
- Tritrix can achieve 106.6dB@1m (or at 4m with 4 speakers/amp channels)
- Aviatrix can achieve 107.7dB@1m
- NatP can achieve 110.8dB@1m
... and you can add 3dB to each as they all have ~2x higher "peak" power ratings

Conversely, if you remember distortion discussion, the farther you operate from maximum limits, the cleaner the sound. You still get what you pay for, even if you don't need it all!

Finally, don't forget a subwoofer. These are all music-capable systems, but LFE and certain types of music need something designed for infrasonics. I'd budget 1/4 to 1/3 here, assuming a large (12-18") driver and 500-1000W amp as minimum requirements.

This is heavy on rationale because a little understanding goes a long way toward a successful DIY project. There's more to be said - center channels, room treatments, placement options, etc. - so let's let someone else chime in!

HAve fun,
Frank

[JMRod]

Thank you fbov for that very informative reply.

I have been reading through your post and trying to understand it completely. There are still some things I dont quite understand but I have lots of research to continue.

The woofer size specs you recommend seem seem very high (woofer size and power). I have an "entertainment center station" built in my home. Basically its a 5 sided box attached to the wall on the right side face its front. The open side is where the TV and speakers would be view from. It seem that this center helps with the bass situation (adds gain?). I can put my current HTIB sub in there and it can sound very loud. I am not saying good or bad just loud for its size. I am not an acoustics expert but I believe this entertainment center station adds some gain to the base.

Again, thank for the reply and information.

[JonMarsh]

VERY nice write up and summary, Frank- appreciate you taking the time to go into this detail- thinking this is something to bookmark and extract as a reference piece.

~Jon