diy studio monitors

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I've come up with a plan for a pair of studio monitors. Using the HI VI f8, and the HI VI RT2C planar tweeter because of their incrediblely flat frequency response. Now the cabinets I want to build would be 16"wx10"dx24"h outside dementions. Giving me an internal volume of 1.64 cu ft, and with a slot port of 8.5"dx12.825"wx1.5"h would give me bass down to 32Hz so I wouldn't even need a sub. These should fit nicely on my studio table and just by coincidence fit the golden ratio almost perfectly. I would need some help designing the crossovers but I think I want to do first order around 2000hz and a 4 db attenuation ciurcut for the tweeter. please let me know what you think.

thanks
Brett R. Sanko

P.S. my internal volume includes the port I don't know whether it should or not.
 
A 1st order crossover will theoretically give perfect reconstruction and superb transient response however, it places the greatest demands on the drivers. The drivers need to be 0deg phase and flat response for about 2 octaves either side of crossover. Usually they are not and this causes magnitude and phase errors around the crossover point.

See if you can find Richard Small's AES paper on constant voltage crossovers for an excellent discussion.

wrt the port, you need to subtract the volume of the port plus 5% or so for fringe effects to get the true internal volume. Don't forget to subtract the volume of the drivers as well.
 
Ex-Moderator R.I.P.
Joined 2005
I have been looking at the RT2II which is useabledown to 2khz, but may be a bit optimistic

The RT2C is only recommendable down to 3khz

That is from specs chart and I suppose this is with 2.order filter ... 1.order 6db wont do at these frequencies
 
actually the spec sheet says recomended x-over point >1700Hz so 2000Hz should work but like you saidonly 2nd order. I definitely don't have the 2 octives of flat resonse below that so I guess a 1st order wouldn't work too good at this frequency. The woofer response gets ugly above 2500Hz so I don't want to go to high. here are the response charts. Let me know what you think the best solution would be. Maybe I need to pick a different tweeter alltogether.
 

Attachments

  • monitor drivers resp.jpeg
    monitor drivers resp.jpeg
    91.7 KB · Views: 1,939
Ex-Moderator R.I.P.
Joined 2005
Obviously old spec sheets saved at PE:D I suppose specs on Hivi site is up to date

Response curve seem a bit different too ... maybe its an older model ... weight is a bit different too, so I suppose it has been changed a bit

But without proper xo nothing will work :bawling:
 
Ex-Moderator R.I.P.
Joined 2005
A Peerless SLS 10" in 50liter closed and a Fostex FE87e might work with 6db filter ... but will it work? ... I would think it depends on the small fullrange about which I havent got a clew :clown:
but there are also TBs and Jordan ... and FR125, but low on SPL ... some like all those small fullrange drivers ... others think they dont live up to their reputation
You might be better off chosing a well proven design
 
Something very similar to what I'm planning on doing might work pretty well with some good benefits for this application if done right..

Seas T18RE/XFCTV2 (H1333) 7" Coaxial with crossover from Madisound, and if you're willing to go ported, a Dayton RSS210HF-4 actively crossed around 250 Hz LR4. You could go larger on the bass if desired, but going by your first post, I would think you'd find this more than satisfying. I just ordered a pair of these Seas coaxials myself with the Madisound crossovers the other night, planning to pair them with 2-4 10" or possibly 2 12" RS drivers per side, then build a matching center channel, and then 4 single coaxes for rear and side channels for 7.1 HT. It'll also be used for music a large portion of the time. Definitely a unique setup, I think. Depending on how close you are in relation to distance from the speakers, I think dual concentrics like these might have a big advantage to offer, especially if you're sitting anywhere within a 3 meters or so. My living room here is fairly small.

http://www.madisound.com/catalog/product_info.php?products_id=1696
http://www.madisound.com/catalog/ad...=1&inc_subcat=1&imageField.x=0&imageField.y=0
 
Flat FR is only one factor in the choice of a driver. You should also consider its distortion performance. I do not think the HiVi planar tweeter has good low-end (e.g., below 3 kHz) distortion performance. Usually, ribbon or planar tweeters have much higher distortions as frequency goes down. This is why a higher xo frequency is recommended with this type of tweeter.

If you choose and design carefully, a 2-way with an 8" woofer and a 1" dome tweeter is possible. For example, look at this design: http://www.markk.claub.net/RS225_RS28A_updates/dayton_reference_rs225.htm If you want, you can build a vented version of this excellent design.

Or if you want very high quality monitor speakers, consider a 2-way with Peerless HDS Exclusive 830884 8" midbass driver and HDS 810921 1" dome tweeter. They are very low distortion drivers. An acoustic (not electrical) 4th order filters will work very well for these. If you're interested, also look at my comment in the following post: http://www.diyaudio.com/forums/showthread.php?postid=1319026#post1319026
 
okay call me fickel but I have a whole new design. Here goes.

Vifa P17SJ-00 6.5" woofer
Vifa D27TG-05-06 1" FABRIC DOME TWEETER
In an aproximately .38 cu ft sealed box (7"x16"x10"outside)
Dayton RSS265HF-4 10" Subwoofer in a 2 cu ft ported box (f3:22hz)
All powered by a 5 channel amp and an electronic crossover set at 85hz and 2khz
And of course a 2 channel preamp
 
Those Vifa's may not be bad drivers. But they are quite old designs. When you choose drivers, I suggest relying on measurement data, espeically distortion measurements---not on just your guess. Have you looked at Zaph's driver test pages? He tested virtually all 6.5" midbass drivers and tweeters currently available on the DIY market. Also, Mark Krawiec performed very thorough tests on some of those drivers.

You can find some of the most cost-effective 6.5" 2-way designs at my website. Two are built designs and the other two are preliminary. Driver selections of these designs were based on the above test data. So the goal was to combine drivers that would give the cleanest (i.e. with lowest possible distortions) sounding 2-way speakers given the price.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.